Add superpipe supporting infrastructure to device driver for the IBM CXL Flash adapter. This patch allows userspace applications to take advantage of the accelerated I/O features that this adapter provides and bypass the traditional filesystem stack. Signed-off-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx> Signed-off-by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx> --- Documentation/powerpc/cxlflash.txt | 298 ++++++ drivers/scsi/cxlflash/Makefile | 2 +- drivers/scsi/cxlflash/common.h | 17 + drivers/scsi/cxlflash/main.c | 23 +- drivers/scsi/cxlflash/superpipe.c | 2076 ++++++++++++++++++++++++++++++++++++ drivers/scsi/cxlflash/superpipe.h | 142 +++ include/uapi/scsi/Kbuild | 1 + include/uapi/scsi/cxlflash_ioctl.h | 132 +++ 8 files changed, 2689 insertions(+), 2 deletions(-) create mode 100644 Documentation/powerpc/cxlflash.txt create mode 100644 drivers/scsi/cxlflash/superpipe.c create mode 100644 drivers/scsi/cxlflash/superpipe.h create mode 100644 include/uapi/scsi/cxlflash_ioctl.h diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.txt new file mode 100644 index 0000000..c4d3849 --- /dev/null +++ b/Documentation/powerpc/cxlflash.txt @@ -0,0 +1,298 @@ +Introduction +============ + + The IBM Power architecture provides support for CAPI (Coherent + Accelerator Power Interface), which is available to certain PCIe slots + on Power 8 systems. CAPI can be thought of as a special tunneling + protocol through PCIe that allow PCIe adapters to look like special + purpose co-processors which can read or write an application's + memory and generate page faults. As a result, the host interface to + an adapter running in CAPI mode does not require the data buffers to + be mapped to the device's memory (IOMMU bypass) nor does it require + memory to be pinned. + + On Linux, Coherent Accelerator (CXL) kernel services present CAPI + devices as a PCI device by implementing a virtual PCI host bridge. + This abstraction simplifies the infrastructure and programming + model, allowing for drivers to look similar to other native PCI + device drivers. + + CXL provides a mechanism by which user space applications can + directly talk to a device (network or storage) bypassing the typical + kernel/device driver stack. The CXL Flash Adapter Driver enables a + user space application direct access to Flash storage. + + The CXL Flash Adapter Driver is a kernel module that sits in the + SCSI stack as a low level device driver (below the SCSI disk and + protocol drivers) for the IBM CXL Flash Adapter. This driver is + responsible for the initialization of the adapter, setting up the + special path for user space access, and performing error recovery. It + communicates directly the Flash Accelerator Functional Unit (AFU) + as described in Documentation/powerpc/cxl.txt. + + The cxlflash driver supports two, mutually exclusive, modes of + operation at the device (LUN) level: + + - Any flash device (LUN) can be configured to be accessed as a + regular disk device (i.e.: /dev/sdc). This is the default mode. + + - Any flash device (LUN) can be configured to be accessed from + user space with a special block library. This mode further + specifies the means of accessing the device and provides for + either raw access to the entire LUN (referred to as direct + or physical LUN access) or access to a kernel/AFU-mediated + partition of the LUN (referred to as virtual LUN access). The + segmentation of a disk device into virtual LUNs is assisted + by special translation services provided by the Flash AFU. + +Overview +======== + + The Coherent Accelerator Interface Architecture (CAIA) introduces a + concept of a master context. A master typically has special privileges + granted to it by the kernel or hypervisor allowing it to perform AFU + wide management and control. The master may or may not be involved + directly in each user I/O, but at the minimum is involved in the + initial setup before the user application is allowed to send requests + directly to the AFU. + + The CXL Flash Adapter Driver establishes a master context with the + AFU. It uses memory mapped I/O (MMIO) for this control and setup. The + Adapter Problem Space Memory Map looks like this: + + +-------------------------------+ + | 512 * 64 KB User MMIO | + | (per context) | + | User Accessible | + +-------------------------------+ + | 512 * 128 B per context | + | Provisioning and Control | + | Trusted Process accessible | + +-------------------------------+ + | 64 KB Global | + | Trusted Process accessible | + +-------------------------------+ + + This driver configures itself into the SCSI software stack as an + adapter driver. The driver is the only entity that is considered a + Trusted Process to program the Provisioning and Control and Global + areas in the MMIO Space shown above. The master context driver + discovers all LUNs attached to the CXL Flash adapter and instantiates + scsi block devices (/dev/sdb, /dev/sdc etc.) for each unique LUN + seen from each path. + + Once these scsi block devices are instantiated, an application + written to a specification provided by the block library may get + access to the Flash from user space (without requiring a system call). + + This master context driver also provides a series of ioctls for this + block library to enable this user space access. The driver supports + two modes for accessing the block device. + + The first mode is called a virtual mode. In this mode a single scsi + block device (/dev/sdb) may be carved up into any number of distinct + virtual LUNs. The virtual LUNs may be resized as long as the sum of + the sizes of all the virtual LUNs, along with the meta-data associated + with it does not exceed the physical capacity. + + The second mode is called the physical mode. In this mode a single + block device (/dev/sdb) may be opened directly by the block library + and the entire space for the LUN is available to the application. + + Only the physical mode provides persistence of the data. i.e. The + data written to the block device will survive application exit and + restart and also reboot. The virtual LUNs do not persist (i.e. do + not survive after the application terminates or the system reboots). + + +Block library API +================= + + Applications intending to get access to the CXL Flash from user + space should use the block library, as it abstracts the details of + interfacing directly with the cxlflash driver that are necessary for + performing administrative actions (i.e.: setup, tear down, resize). + The block library can be thought of as a 'user' of services, + implemented as IOCTLs, that are provided by the cxlflash driver + specifically for devices (LUNs) operating in user space access + mode. While it is not a requirement that applications understand + the interface between the block library and the cxlflash driver, + a high-level overview of each supported service (IOCTL) is provided + below. + + The block library can be found on GitHub: + http://www.github.com/mikehollinger/ibmcapikv + + +CXL Flash Driver IOCTLs +======================= + + Users, such as the block library, that wish to interface with a flash + device (LUN) via user space access need to use the services provided + by the cxlflash driver. As these services are implemented as ioctls, + a file descriptor handle must first be obtained in order to establish + the communication channel between a user and the kernel. This file + descriptor is obtained by opening the device special file associated + with the scsi disk device (/dev/sdb) that was created during LUN + discovery. As per the location of the cxlflash driver within the + SCSI protocol stack, this open is actually not seen by the cxlflash + driver. Upon successful open, the user receives a file descriptor + (herein referred to as fd1) that should be used for issuing the + subsequent ioctls listed below. + + The structure definitions for these IOCTLs are available in: + uapi/scsi/cxlflash_ioctl.h + +DK_CXLFLASH_ATTACH +------------------ + + This ioctl obtains, initializes, and starts a context using the CXL + kernel services. These services specify a context id (u16) by which + to uniquely identify the context and its allocated resources. The + services additionally provide a second file descriptor (herein + referred to as fd2) that is used by the block library to initiate + memory mapped I/O (via mmap()) to the CXL flash device and poll for + completion events. This file descriptor is intentionally installed by + this driver and not the CXL kernel services to allow for intermediary + notification and access in the event of a non-user-initiated close(), + such as a killed process. This design point is described in further + detail in the description for the DK_CXLFLASH_DETACH ioctl. + + There are a few important aspects regarding the "tokens" (context id + and fd2) that are provided back to the user: + + - These tokens are only valid for the process under which they + were created. The child of a forked process cannot continue + to use the context id or file descriptor created by its parent + (see DK_CXLFLASH_CLONE for further details). + + - These tokens are only valid for the lifetime of the context and + the process under which they were created. Once either is + destroyed, the tokens are to be considered stale and subsequent + usage will result in errors. + + - When a context is no longer needed, the user shall detach from + the context via the DK_CXLFLASH_DETACH ioctl. + + - A close on fd2 will invalidate the tokens. This operation is not + required by the user. + +DK_CXLFLASH_USER_DIRECT +----------------------- + This ioctl is responsible for transitioning the LUN to direct + (physical) mode access and configuring the AFU for direct access from + user space on a per-context basis. Additionally, the block size and + last logical block address (LBA) are returned to the user. + + As mentioned previously, when operating in user space access mode, + LUNs may be accessed in whole or in part. Only one mode is allowed + at a time and if one mode is active (outstanding references exist), + requests to use the LUN in a different mode are denied. + + The AFU is configured for direct access from user space by adding an + entry to the AFU's resource handle table. The index of the entry is + treated as a resource handle that is returned to the user. The user + is then able to use the handle to reference the LUN during I/O. + +DK_CXLFLASH_USER_VIRTUAL +------------------------ + This ioctl is responsible for transitioning the LUN to virtual mode + of access and configuring the AFU for virtual access from user space + on a per-context basis. Additionally, the block size and last logical + block address (LBA) are returned to the user. + + As mentioned previously, when operating in user space access mode, + LUNs may be accessed in whole or in part. Only one mode is allowed + at a time and if one mode is active (outstanding references exist), + requests to use the LUN in a different mode are denied. + + The AFU is configured for virtual access from user space by adding + an entry to the AFU's resource handle table. The index of the entry + is treated as a resource handle that is returned to the user. The + user is then able to use the handle to reference the LUN during I/O. + + By default, the virtual LUN is created with a size of 0. The user + would need to use the DK_CXLFLASH_VLUN_RESIZE ioctl to adjust the grow + the virtual LUN to a desired size. To avoid having to perform this + resize for the initial creation of the virtual LUN, the user has the + option of specifying a size as part of the DK_CXLFLASH_USER_VIRTUAL + ioctl, such that when success is returned to the user, the + resource handle that is provided is already referencing provisioned + storage. This is reflected by the last LBA being a non-zero value. + +DK_CXLFLASH_VLUN_RESIZE +----------------------- + This ioctl is responsible for resizing a previously created virtual + LUN and will fail if invoked upon a LUN that is not in virtual + mode. Upon success, an updated last LBA is returned to the user + indicating the new size of the virtual LUN associated with the + resource handle. + + The partitioning of virtual LUNs is jointly mediated by the cxlflash + driver and the AFU. An allocation table is kept for each LUN that is + operating in the virtual mode and used to program a LUN translation + table that the AFU references when provided with a resource handle. + +DK_CXLFLASH_RELEASE +------------------- + This ioctl is responsible for releasing a previously obtained + reference to either a physical or virtual LUN. This can be + thought of as the inverse of the DK_CXLFLASH_USER_DIRECT or + DK_CXLFLASH_USER_VIRTUAL ioctls. Upon success, the resource handle + is no longer valid and the entry in the resource handle table is + made available to be used again. + + As part of the release process for virtual LUNs, the virtual LUN + is first resized to 0 to clear out and free the translation tables + associated with the virtual LUN reference. + +DK_CXLFLASH_DETACH +------------------ + This ioctl is responsible for unregistering a context with the + cxlflash driver and release outstanding resources that were + not explicitly released via the DK_CXLFLASH_RELEASE ioctl. Upon + success, all "tokens" which had been provided to the user from the + DK_CXLFLASH_ATTACH onward are no longer valid. + +DK_CXLFLASH_CLONE +----------------- + This ioctl is responsible for cloning a previously created + context to a more recently created context. It exists solely to + support maintaining user space access to storage after a process + forks. Upon success, the child process (which invoked the ioctl) + will have access to the same LUNs via the same resource handle(s) + and fd2 as the parent, but under a different context. + + Context sharing across processes is not supported with CXL and + therefore each fork must be met with establishing a new context + for the child process. This ioctl simplifies the state management + and playback required by a user in such a scenario. When a process + forks, child process can clone the parents context by first creating + a context (via DK_CXLFLASH_ATTACH) and then using this ioctl to + perform the clone from the parent to the child. + + The clone itself is fairly simple. The resource handle and lun + translation tables are copied from the parent context to the child's + and then synced with the AFU. + +DK_CXLFLASH_VERIFY +------------------ + The DK_CXLFLASH_VERIFY ioctl is used to detect various changes such + as the capacity of the disk changing, the number of LUNs visible + changing, etc. In cases where the changes affect the application + (such as a LUN resize), the cxlflash driver will report the changed + state to the application. + +DK_CXLFLASH_RECOVER_AFU +----------------------- + This ioctl is used to drive recovery (if such an action is warranted) + by resetting the adapter. Any state associated with all the open + contexts, will be re-established. + +DK_CXLFLASH_MANAGE_LUN +---------------------- + This ioctl is used to switch a LUN from a mode where it is available + for file-system access (legacy), to a mode where it is set aside for + exclusive user space access (superpipe). In case a LUN is visible + across multiple ports and adapters, this ioctl is used to uniquely + identify each LUN by its World Wide Node Name (WWNN). diff --git a/drivers/scsi/cxlflash/Makefile b/drivers/scsi/cxlflash/Makefile index dc95e20..3de309c 100644 --- a/drivers/scsi/cxlflash/Makefile +++ b/drivers/scsi/cxlflash/Makefile @@ -1,2 +1,2 @@ obj-$(CONFIG_CXLFLASH) += cxlflash.o -cxlflash-y += main.o +cxlflash-y += main.o superpipe.o diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h index 155c2f7..3b16857 100644 --- a/drivers/scsi/cxlflash/common.h +++ b/drivers/scsi/cxlflash/common.h @@ -107,6 +107,16 @@ struct cxlflash_cfg { struct pci_pool *cxlflash_cmd_pool; struct pci_dev *parent_dev; + struct mutex ctx_tbl_list_mutex; + struct ctx_info *ctx_tbl[MAX_CONTEXT]; + struct list_head ctx_err_recovery; /* contexts w/ recovery pending */ + struct file_operations cxl_fops; + + atomic_t num_user_contexts; + + struct list_head lluns; /* list of llun_info structs */ + spinlock_t slock; + wait_queue_head_t tmf_waitq; bool tmf_active; wait_queue_head_t eeh_waitq; @@ -182,5 +192,12 @@ int cxlflash_afu_reset(struct cxlflash_cfg *); struct afu_cmd *cxlflash_cmd_checkout(struct afu *); void cxlflash_cmd_checkin(struct afu_cmd *); int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8); +void cxlflash_list_init(void); +void cxlflash_list_terminate(void); +int cxlflash_ioctl(struct scsi_device *, int, void __user *); +void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *); +int cxlflash_mark_contexts_error(struct cxlflash_cfg *); +void cxlflash_term_luns(struct cxlflash_cfg *); + #endif /* ifndef _CXLFLASH_COMMON_H */ diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index e1f93ef..b87964b 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -498,11 +498,15 @@ static int cxlflash_eh_host_reset_handler(struct scsi_cmnd *scp) switch (cfg->eeh_active) { case EEH_STATE_NONE: + cfg->eeh_active = EEH_STATE_FAILED; + cxlflash_mark_contexts_error(cfg); rcr = cxlflash_afu_reset(cfg); if (rcr == 0) rc = SUCCESS; else rc = FAILED; + cfg->eeh_active = EEH_STATE_NONE; + wake_up_all(&cfg->eeh_waitq); break; case EEH_STATE_ACTIVE: wait_event(cfg->eeh_waitq, cfg->eeh_active != EEH_STATE_ACTIVE); @@ -697,6 +701,7 @@ static struct scsi_host_template driver_template = { .module = THIS_MODULE, .name = CXLFLASH_ADAPTER_NAME, .info = cxlflash_driver_info, + .ioctl = cxlflash_ioctl, .proc_name = CXLFLASH_NAME, .queuecommand = cxlflash_queuecommand, .eh_device_reset_handler = cxlflash_eh_device_reset_handler, @@ -845,6 +850,7 @@ static void cxlflash_remove(struct pci_dev *pdev) switch (cfg->init_state) { case INIT_STATE_SCSI: + cxlflash_term_luns(cfg); scsi_remove_host(cfg->host); scsi_host_put(cfg->host); /* Fall through */ @@ -1984,7 +1990,7 @@ retry: } else if (unlikely(newval < 0)) { /* This should be rare. i.e. Only if two threads race and * decrement before the MMIO read is done. In this case - * just benefit from the other thread having updated + * just benefit from the other thread having updated * afu->room. */ if (nretry++ < MC_ROOM_RETRY_CNT) { @@ -2244,6 +2250,11 @@ static int cxlflash_probe(struct pci_dev *pdev, INIT_WORK(&cfg->work_q, cxlflash_worker_thread); cfg->lr_state = LINK_RESET_INVALID; cfg->lr_port = -1; + mutex_init(&cfg->ctx_tbl_list_mutex); + spin_lock_init(&cfg->slock); + INIT_LIST_HEAD(&cfg->ctx_err_recovery); + INIT_LIST_HEAD(&cfg->lluns); + pci_set_drvdata(pdev, cfg); @@ -2305,6 +2316,7 @@ out_remove: static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev, pci_channel_state_t state) { + int rc = 0; struct cxlflash_cfg *cfg = pci_get_drvdata(pdev); pr_debug("%s: pdev=%p state=%u\n", __func__, pdev, state); @@ -2314,6 +2326,11 @@ static pci_ers_result_t cxlflash_pci_error_detected(struct pci_dev *pdev, cfg->eeh_active = EEH_STATE_ACTIVE; udelay(100); + rc = cxlflash_mark_contexts_error(cfg); + if (unlikely(rc)) + pr_err("%s: Failed to mark contexts in error!(rc=%d)\n", + __func__, rc); + term_mc(cfg, UNDO_START); stop_afu(cfg); @@ -2394,6 +2411,8 @@ static int __init init_cxlflash(void) pr_info("%s: IBM Power CXL Flash Adapter: %s\n", __func__, CXLFLASH_DRIVER_DATE); + cxlflash_list_init(); + return pci_register_driver(&cxlflash_driver); } @@ -2402,6 +2421,8 @@ static int __init init_cxlflash(void) */ static void __exit exit_cxlflash(void) { + cxlflash_list_terminate(); + pci_unregister_driver(&cxlflash_driver); } diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c new file mode 100644 index 0000000..631cc6b --- /dev/null +++ b/drivers/scsi/cxlflash/superpipe.c @@ -0,0 +1,2076 @@ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/delay.h> +#include <linux/file.h> +#include <linux/moduleparam.h> +#include <linux/syscalls.h> +#include <misc/cxl.h> +#include <asm/unaligned.h> + +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi_cmnd.h> +#include <uapi/scsi/cxlflash_ioctl.h> + +#include "sislite.h" +#include "common.h" +#include "superpipe.h" + +static struct cxlflash_global global; + +/** + * marshal_det_to_rele() - translate detach to release structure + * @detach: Destination structure for the translate/copy. + * @rele: Source structure from which to translate/copy. + */ +static void marshal_det_to_rele(struct dk_cxlflash_detach *detach, + struct dk_cxlflash_release *release) +{ + release->hdr = detach->hdr; + release->context_id = detach->context_id; +} + +/** + * create_local() - allocate and initialize a local LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: World Wide Node Name for LUN. + * + * Return: Allocated local llun_info structure on success, NULL on failure + */ +static struct llun_info *create_local(struct scsi_device *sdev, u8 *wwid) +{ + struct llun_info *lli = NULL; + + lli = kzalloc(sizeof(*lli), GFP_KERNEL); + if (unlikely(!lli)) { + pr_err("%s: could not allocate lli\n", __func__); + goto out; + } + + lli->sdev = sdev; + lli->newly_created = true; + lli->host_no = sdev->host->host_no; + lli->in_table = false; + + memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN); +out: + return lli; +} + +/** + * create_global() - allocate and initialize a global LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: World Wide Node Name for LUN. + * + * Return: Allocated global glun_info structure on success, NULL on failure + */ +static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid) +{ + struct glun_info *gli = NULL; + + gli = kzalloc(sizeof(*gli), GFP_KERNEL); + if (unlikely(!gli)) { + pr_err("%s: could not allocate gli\n", __func__); + goto out; + } + + memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN); +out: + return gli; +} + +/** + * lookup_local() - find a local LUN information structure by WWID + * @cfg: Internal structure associated with the host. + * @wwid: WWID associated with LUN. + * + * Return: Found local lun_info structure on success, NULL on failure + */ +static struct llun_info *lookup_local(struct cxlflash_cfg *cfg, u8 *wwid) +{ + struct llun_info *lli, *temp; + ulong lock_flags; + + spin_lock_irqsave(&cfg->slock, lock_flags); + + list_for_each_entry_safe(lli, temp, &cfg->lluns, list) + if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN)) { + lli->newly_created = false; + spin_unlock_irqrestore(&cfg->slock, lock_flags); + return lli; + } + + spin_unlock_irqrestore(&cfg->slock, lock_flags); + return NULL; +} + +/** + * lookup_global() - find a global LUN information structure by WWID + * @wwid: WWID associated with LUN. + * + * Return: Found global lun_info structure on success, NULL on failure + */ +static struct glun_info *lookup_global(u8 *wwid) +{ + struct glun_info *gli, *temp; + ulong lock_flags; + + spin_lock_irqsave(&global.slock, lock_flags); + + list_for_each_entry_safe(gli, temp, &global.gluns, list) + if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN)) { + spin_unlock_irqrestore(&global.slock, lock_flags); + return gli; + } + + spin_unlock_irqrestore(&global.slock, lock_flags); + return NULL; +} + +/** + * lookup_lun() - find or create a local LUN information structure + * @sdev: SCSI device associated with LUN. + * @wwid: WWID associated with LUN. + * + * When a local LUN is not found and a global LUN is also not found, both + * a global LUN and local LUN are created. The global LUN is added to the + * global list and the local LUN is returned. + * + * Return: Found/Allocated local lun_info structure on success, NULL on failure + */ +static struct llun_info *lookup_lun(struct scsi_device *sdev, u8 *wwid) +{ + struct llun_info *lli = NULL; + struct glun_info *gli = NULL; + struct Scsi_Host *shost = sdev->host; + struct cxlflash_cfg *cfg = shost_priv(shost); + ulong lock_flags; + + if (unlikely(!wwid)) + goto out; + + lli = lookup_local(cfg, wwid); + if (lli) + goto out; + + lli = create_local(sdev, wwid); + if (unlikely(!lli)) + goto out; + + gli = lookup_global(wwid); + if (gli) { + lli->parent = gli; + spin_lock_irqsave(&cfg->slock, lock_flags); + list_add(&lli->list, &cfg->lluns); + spin_unlock_irqrestore(&cfg->slock, lock_flags); + goto out; + } + + gli = create_global(sdev, wwid); + if (unlikely(!gli)) { + kfree(lli); + lli = NULL; + goto out; + } + + lli->parent = gli; + spin_lock_irqsave(&cfg->slock, lock_flags); + list_add(&lli->list, &cfg->lluns); + spin_unlock_irqrestore(&cfg->slock, lock_flags); + + spin_lock_irqsave(&global.slock, lock_flags); + list_add(&gli->list, &global.gluns); + spin_unlock_irqrestore(&global.slock, lock_flags); + +out: + pr_debug("%s: returning %p\n", __func__, lli); + return lli; +} + +/** + * cxlflash_term_luns() - Delete all entries from local lun list, free. + * @cfg: Internal structure associated with the host. + */ +void cxlflash_term_luns(struct cxlflash_cfg *cfg) +{ + struct llun_info *lli, *temp; + ulong lock_flags; + + spin_lock_irqsave(&cfg->slock, lock_flags); + list_for_each_entry_safe(lli, temp, &cfg->lluns, list) { + list_del(&lli->list); + kfree(lli); + } + spin_unlock_irqrestore(&cfg->slock, lock_flags); +} + +/** + * cxlflash_list_init() - initializes the global LUN list + */ +void cxlflash_list_init(void) +{ + INIT_LIST_HEAD(&global.gluns); + spin_lock_init(&global.slock); + global.err_page = NULL; +} + +/** + * cxlflash_list_terminate() - frees resources associated with global LUN list + */ +void cxlflash_list_terminate(void) +{ + struct glun_info *gli, *temp; + ulong flags = 0; + + spin_lock_irqsave(&global.slock, flags); + list_for_each_entry_safe(gli, temp, &global.gluns, list) { + list_del(&gli->list); + kfree(gli); + } + + if (global.err_page) { + __free_page(global.err_page); + global.err_page = NULL; + } + spin_unlock_irqrestore(&global.slock, flags); +} + +/** + * cxlflash_stop_term_user_contexts() - stops/terminates known user contexts + * @cfg: Internal structure associated with the host. + * + * When the host needs to go down, all users must be quiesced and their + * memory freed. This is accomplished by putting the contexts in error + * state which will notify the user and let them 'drive' the teardown. + * Meanwhile, this routine camps until all user contexts have been removed. + */ +void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg) +{ + int i, found; + + cfg->eeh_active = EEH_STATE_FAILED; + cxlflash_mark_contexts_error(cfg); + + while (true) { + found = false; + + for (i = 0; i < MAX_CONTEXT; i++) + if (cfg->ctx_tbl[i]) { + found = true; + break; + } + + if (!found && list_empty(&cfg->ctx_err_recovery)) + return; + + pr_debug("%s: Wait for user context to quiesce...\n", __func__); + wake_up_all(&cfg->eeh_waitq); + ssleep(1); + } +} + +/** + * find_error_context() - locates a context by cookie on the error recovery list + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context by id. + * @file: Desired context by file. + * + * Return: Found context on success, NULL on failure + */ +static struct ctx_info *find_error_context(struct cxlflash_cfg *cfg, u64 rctxid, + struct file *file) +{ + struct ctx_info *ctxi; + + list_for_each_entry(ctxi, &cfg->ctx_err_recovery, list) + if ((ctxi->ctxid == rctxid) || (ctxi->file == file)) + return ctxi; + + return NULL; +} + +/** + * get_context() - obtains a validated and locked context reference + * @cfg: Internal structure associated with the host. + * @rctxid: Desired context (raw, undecoded format). + * @arg: LUN information or file associated with request. + * @ctx_ctrl: Control information to 'steer' desired lookup. + * + * NOTE: despite the name pid, in linux, current->pid actually refers + * to the lightweight process id (tid) and can change if the process is + * multi threaded. The tgid remains constant for the process and only changes + * when the process of fork. For all intents and purposes, think of tgid + * as a pid in the traditional sense. + * + * Return: Validated context on success, NULL on failure + */ +struct ctx_info *get_context(struct cxlflash_cfg *cfg, u64 rctxid, + void *arg, enum ctx_ctrl ctx_ctrl) +{ + struct ctx_info *ctxi = NULL; + struct lun_access *lun_access = NULL; + struct file *file = NULL; + struct llun_info *lli = arg; + u64 ctxid = DECODE_CTXID(rctxid); + int rc; + pid_t pid = current->tgid, ctxpid = 0; + + if (ctx_ctrl & CTX_CTRL_FILE) { + lli = NULL; + file = (struct file *)arg; + } + + if (ctx_ctrl & CTX_CTRL_CLONE) + pid = current->parent->tgid; + + if (likely(ctxid < MAX_CONTEXT)) { +retry: + rc = mutex_lock_interruptible(&cfg->ctx_tbl_list_mutex); + if (rc) + goto out; + + ctxi = cfg->ctx_tbl[ctxid]; + if (ctxi) + if ((file && (ctxi->file != file)) || + (!file && (ctxi->ctxid != rctxid))) + ctxi = NULL; + + if ((ctx_ctrl & CTX_CTRL_ERR) || + (!ctxi && (ctx_ctrl & CTX_CTRL_ERR_FALLBACK))) + ctxi = find_error_context(cfg, rctxid, file); + mutex_unlock(&cfg->ctx_tbl_list_mutex); + if (!ctxi) + goto out; + + rc = mutex_trylock(&ctxi->mutex); + if (!rc) + goto retry; + + ctxpid = ctxi->pid; + if (likely(!(ctx_ctrl & CTX_CTRL_NOPID))) + if (pid != ctxpid) + goto denied; + + if (lli) { + list_for_each_entry(lun_access, &ctxi->luns, list) + if (lun_access->lli == lli) + goto out; + goto denied; + } + } + +out: + pr_debug("%s: rctxid=%016llX ctxinfo=%p ctxpid=%u pid=%u ctx_ctrl=%u\n", + __func__, rctxid, ctxi, ctxpid, pid, ctx_ctrl); + + return ctxi; + +denied: + mutex_unlock(&ctxi->mutex); + ctxi = NULL; + goto out; +} + +/** + * afu_attach() - attach a context to the AFU + * @cfg: Internal structure associated with the host. + * @ctxi: Context to attach. + * + * Upon setting the context capabilities, they must be confirmed with + * a read back operation as the context might have been closed since + * the mailbox was unlocked. When this occurs, registration is failed. + * + * Return: 0 on success, -errno on failure + */ +static int afu_attach(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) +{ + struct afu *afu = cfg->afu; + struct sisl_ctrl_map *ctrl_map = ctxi->ctrl_map; + int rc = 0; + u64 val; + + /* Unlock cap and restrict user to read/write cmds in translated mode */ + readq_be(&ctrl_map->mbox_r); + val = (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD); + writeq_be(val, &ctrl_map->ctx_cap); + val = readq_be(&ctrl_map->ctx_cap); + if (val != (SISL_CTX_CAP_READ_CMD | SISL_CTX_CAP_WRITE_CMD)) { + pr_err("%s: ctx may be closed val=%016llX\n", __func__, val); + rc = -EAGAIN; + goto out; + } + + /* Set up MMIO registers pointing to the RHT */ + writeq_be((u64)ctxi->rht_start, &ctrl_map->rht_start); + val = SISL_RHT_CNT_ID((u64)MAX_RHT_PER_CONTEXT, (u64)(afu->ctx_hndl)); + writeq_be(val, &ctrl_map->rht_cnt_id); +out: + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * read_cap16() - issues a SCSI READ_CAP16 command + * @sdev: SCSI device associated with LUN. + * @lli: LUN destined for capacity request. + * + * Return: 0 on success, -1 on failure + */ +static int read_cap16(struct scsi_device *sdev, struct llun_info *lli) +{ + struct glun_info *gli = lli->parent; + u8 scsi_cmd[MAX_COMMAND_SIZE]; + u8 *cmd_buf = NULL; + u8 *sense_buf = NULL; + int rc = 0; + int result = 0; + + memset(scsi_cmd, 0, sizeof(scsi_cmd)); + cmd_buf = kzalloc(CMD_BUFSIZE, GFP_KERNEL); + sense_buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); + if (!cmd_buf || !sense_buf) { + rc = -ENOMEM; + goto out; + } + + scsi_cmd[0] = SERVICE_ACTION_IN_16; /* read cap(16) */ + scsi_cmd[1] = SAI_READ_CAPACITY_16; /* service action */ + put_unaligned_be32(CMD_BUFSIZE, &scsi_cmd[10]); + + pr_debug("%s: sending cmd(0x%x)\n", __func__, scsi_cmd[0]); + + result = scsi_execute(sdev, scsi_cmd, DMA_FROM_DEVICE, cmd_buf, + CMD_BUFSIZE, sense_buf, + (MC_DISCOVERY_TIMEOUT*HZ), 5, 0, NULL); + + if (result) { + pr_err("%s: command failed, result=0x%x\n", __func__, result); + rc = -EIO; + goto out; + } + + /* + * Read cap was successful, grab values from the buffer; + * note that we don't need to worry about unaligned access + * as the buffer is allocated on an aligned boundary. + */ + spin_lock(&gli->slock); + gli->max_lba = swab64(*((u64 *)&cmd_buf[0])); + gli->blk_len = swab32(*((u32 *)&cmd_buf[8])); + spin_unlock(&gli->slock); + +out: + kfree(cmd_buf); + kfree(sense_buf); + pr_debug("%s: maxlba=%lld blklen=%d rc=%d\n", __func__, + gli->max_lba, gli->blk_len, rc); + return rc; +} + +/** + * get_rhte() - obtains validated resource handle table entry reference + * @ctxi: Context owning the resource handle. + * @rhndl: Resource handle associated with entry. + * @lli: LUN associated with request. + * + * Return: Validated RHTE on success, NULL on failure + */ +struct sisl_rht_entry *get_rhte(struct ctx_info *ctxi, res_hndl_t rhndl, + struct llun_info *lli) +{ + struct sisl_rht_entry *rhte = NULL; + + if (unlikely(!ctxi->rht_start)) { + pr_err("%s: Context does not have allocated RHT!\n", __func__); + goto out; + } + + if (unlikely(rhndl >= MAX_RHT_PER_CONTEXT)) { + pr_err("%s: Bad resource handle! (%d)\n", __func__, rhndl); + goto out; + } + + if (unlikely(ctxi->rht_lun[rhndl] != lli)) { + pr_err("%s: Bad resource handle LUN! (%d)\n", __func__, rhndl); + goto out; + } + + rhte = &ctxi->rht_start[rhndl]; + if (unlikely(rhte->nmask == 0)) { + pr_err("%s: Unopened resource handle! (%d)\n", __func__, rhndl); + rhte = NULL; + goto out; + } + +out: + return rhte; +} + +/** + * rhte_checkout() - obtains free/empty resource handle table entry + * @ctxi: Context owning the resource handle. + * @lli: LUN associated with request. + * + * Return: Free RHTE on success, NULL on failure + */ +struct sisl_rht_entry *rhte_checkout(struct ctx_info *ctxi, + struct llun_info *lli) +{ + struct sisl_rht_entry *rhte = NULL; + int i; + + /* Find a free RHT entry */ + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) + if (ctxi->rht_start[i].nmask == 0) { + rhte = &ctxi->rht_start[i]; + ctxi->rht_out++; + break; + } + + if (likely(rhte)) + ctxi->rht_lun[i] = lli; + + pr_debug("%s: returning rhte=%p (%d)\n", __func__, rhte, i); + return rhte; +} + +/** + * rhte_checkin() - releases a resource handle table entry + * @ctxi: Context owning the resource handle. + * @rhte: RHTE to release. + */ +void rhte_checkin(struct ctx_info *ctxi, + struct sisl_rht_entry *rhte) +{ + rhte->nmask = 0; + rhte->fp = 0; + ctxi->rht_out--; + ctxi->rht_lun[rhte - ctxi->rht_start] = NULL; +} + +/** + * rhte_format1() - populates a RHTE for format 1 + * @rhte: RHTE to populate. + * @lun_id: LUN ID of LUN associated with RHTE. + * @perm: Desired permissions for RHTE. + * @port_sel: Port selection mask + */ +static void rht_format1(struct sisl_rht_entry *rhte, u64 lun_id, u32 perm, + u32 port_sel) +{ + /* + * Populate the Format 1 RHT entry for direct access (physical + * LUN) using the synchronization sequence defined in the + * SISLite specification. + */ + struct sisl_rht_entry_f1 dummy = { 0 }; + struct sisl_rht_entry_f1 *rhte_f1 = (struct sisl_rht_entry_f1 *)rhte; + + memset(rhte_f1, 0, sizeof(*rhte_f1)); + rhte_f1->fp = SISL_RHT_FP(1U, 0); + dma_wmb(); /* Make setting of format bit visible */ + + rhte_f1->lun_id = lun_id; + dma_wmb(); /* Make setting of LUN id visible */ + + /* + * Use a dummy RHT Format 1 entry to build the second dword + * of the entry that must be populated in a single write when + * enabled (valid bit set to TRUE). + */ + dummy.valid = 0x80; + dummy.fp = SISL_RHT_FP(1U, perm); + dummy.port_sel = port_sel; + rhte_f1->dw = dummy.dw; + + dma_wmb(); /* Make remaining RHT entry fields visible */ +} + +/** + * cxlflash_lun_attach() - attaches a user to a LUN and manages the LUN's mode + * @lli: LUN to attach. + * @mode: Desired mode of the LUN. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_lun_attach(struct glun_info *gli, enum lun_mode mode) +{ + int rc = 0; + + spin_lock(&gli->slock); + if (gli->mode == MODE_NONE) + gli->mode = mode; + else if (gli->mode != mode) { + pr_err("%s: LUN operating in mode %d, requested mode %d\n", + __func__, gli->mode, mode); + rc = -EINVAL; + goto out; + } + + gli->users++; + WARN_ON(gli->users <= 0); +out: + pr_debug("%s: Returning rc=%d gli->mode=%u gli->users=%u\n", + __func__, rc, gli->mode, gli->users); + spin_unlock(&gli->slock); + return rc; +} + +/** + * cxlflash_lun_detach() - detaches a user from a LUN and resets the LUN's mode + * @lli: LUN to detach. + */ +void cxlflash_lun_detach(struct glun_info *gli) +{ + spin_lock(&gli->slock); + WARN_ON(gli->mode == MODE_NONE); + if (--gli->users == 0) + gli->mode = MODE_NONE; + pr_debug("%s: gli->users=%u\n", __func__, gli->users); + WARN_ON(gli->users < 0); + spin_unlock(&gli->slock); +} + +/** + * _cxlflash_disk_release() - releases the specified resource entry + * @sdev: SCSI device associated with LUN. + * @ctxi: Context owning resources. + * @release: Release ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +int _cxlflash_disk_release(struct scsi_device *sdev, + struct ctx_info *ctxi, + struct dk_cxlflash_release *release) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct afu *afu = cfg->afu; + bool unlock_ctx = false; + + res_hndl_t rhndl = release->rsrc_handle; + + int rc = 0; + u64 ctxid = DECODE_CTXID(release->context_id), + rctxid = release->context_id; + + struct sisl_rht_entry *rhte; + struct sisl_rht_entry_f1 *rhte_f1; + + pr_debug("%s: ctxid=%llu rhndl=0x%llx gli->mode=%u gli->users=%u\n", + __func__, ctxid, release->rsrc_handle, gli->mode, gli->users); + + if (!ctxi) { + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%llu)\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + unlock_ctx = true; + } + + rhte = get_rhte(ctxi, rhndl, lli); + if (unlikely(!rhte)) { + pr_err("%s: Bad resource handle! (%d)\n", __func__, rhndl); + rc = -EINVAL; + goto out; + } + + switch (gli->mode) { + case MODE_PHYSICAL: + /* + * Clear the Format 1 RHT entry for direct access + * (physical LUN) using the synchronization sequence + * defined in the SISLite specification. + */ + rhte_f1 = (struct sisl_rht_entry_f1 *)rhte; + + rhte_f1->valid = 0; + dma_wmb(); /* Make revocation of RHT entry visible */ + + rhte_f1->lun_id = 0; + dma_wmb(); /* Make clearing of LUN id visible */ + + rhte_f1->dw = 0; + dma_wmb(); /* Make RHT entry bottom-half clearing visible */ + + cxlflash_afu_sync(afu, ctxid, rhndl, AFU_HW_SYNC); + break; + default: + BUG(); + goto out; + } + + rhte_checkin(ctxi, rhte); + cxlflash_lun_detach(gli); + +out: + if (unlock_ctx) + mutex_unlock(&ctxi->mutex); + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; +} + +int cxlflash_disk_release(struct scsi_device *sdev, + struct dk_cxlflash_release *release) +{ + return _cxlflash_disk_release(sdev, NULL, release); +} + +/** + * destroy_context() - releases a context + * @cfg: Internal structure associated with the host. + * @ctxi: Context to release. + * + * Note that the rht_lun member of the context was cut from a single + * allocation when the context was created and therefore does not need + * to be explicitly freed. Also note that we conditionally check for the + * existence of the context control map before clearing the RHT registers + * and context capbilities because it is possible to destroy a context + * while the context is in the error state (previous mapping was removed + * [so we don't have to worry about clearing] and context is waiting for + * a new mapping). + */ +static void destroy_context(struct cxlflash_cfg *cfg, + struct ctx_info *ctxi) +{ + WARN_ON(!list_empty(&ctxi->luns)); + + /* Clear RHT registers and drop all capabilities for this context */ + if (ctxi->ctrl_map) { + writeq_be(0, &ctxi->ctrl_map->rht_start); + writeq_be(0, &ctxi->ctrl_map->rht_cnt_id); + writeq_be(0, &ctxi->ctrl_map->ctx_cap); + } + + /* Free the RHT memory */ + free_page((ulong)ctxi->rht_start); + + /* Free the context; note that rht_lun was allocated at same time */ + kfree(ctxi); + atomic_dec_if_positive(&cfg->num_user_contexts); +} + +/** + * create_context() - allocates and initializes a context + * @cfg: Internal structure associated with the host. + * @ctx: Previously obtained CXL context reference. + * @ctxid: Previously obtained process element associated with CXL context. + * @adap_fd: Previously obtained adapter fd associated with CXL context. + * @file: Previously obtained file associated with CXL context. + * @perms: User-specified permissions. + * + * The context's mutex is locked when an allocated context is returned. + * + * Return: Allocated context on success, NULL on failure + */ +static struct ctx_info *create_context(struct cxlflash_cfg *cfg, + struct cxl_context *ctx, int ctxid, + int adap_fd, struct file *file, + u32 perms) +{ + char *tmp = NULL; + size_t size; + struct afu *afu = cfg->afu; + struct ctx_info *ctxi = NULL; + struct sisl_rht_entry *rhte; + + size = (MAX_RHT_PER_CONTEXT * sizeof(*ctxi->rht_lun)); + size += sizeof(*ctxi); + + tmp = kzalloc(size, GFP_KERNEL); + if (unlikely(!tmp)) { + pr_err("%s: Unable to allocate context! (%ld)\n", + __func__, size); + goto out; + } + + rhte = (struct sisl_rht_entry *)get_zeroed_page(GFP_KERNEL); + if (unlikely(!rhte)) { + pr_err("%s: Unable to allocate RHT!\n", __func__); + goto err; + } + + ctxi = (struct ctx_info *)tmp; + ctxi->rht_lun = (struct llun_info **)(tmp + sizeof(*ctxi)); + ctxi->rht_start = rhte; + ctxi->rht_perms = perms; + + ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl; + ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid); + ctxi->lfd = adap_fd; + ctxi->pid = current->tgid; /* tgid = pid */ + ctxi->ctx = ctx; + ctxi->file = file; + mutex_init(&ctxi->mutex); + INIT_LIST_HEAD(&ctxi->luns); + INIT_LIST_HEAD(&ctxi->list); /* initialize for list_empty() */ + + atomic_inc(&cfg->num_user_contexts); + mutex_lock(&ctxi->mutex); +out: + return ctxi; + +err: + kfree(tmp); + goto out; +} + +/** + * _cxlflash_disk_detach() - detaches a LUN from a context + * @sdev: SCSI device associated with LUN. + * @ctxi: Context owning resources. + * @detach: Detach ioctl data structure. + * + * As part of the detach, all per-context resources associated with the LUN + * are cleaned up. When detaching the last LUN for a context, the context + * itself is cleaned up and released. + * + * Return: 0 on success, -errno on failure + */ +static int _cxlflash_disk_detach(struct scsi_device *sdev, + struct ctx_info *ctxi, + struct dk_cxlflash_detach *detach) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct llun_info *lli = sdev->hostdata; + struct lun_access *lun_access, *t; + struct dk_cxlflash_release rel; + bool unlock_ctx = false; + + int i; + int rc = 0; + int lfd; + u64 ctxid = DECODE_CTXID(detach->context_id), + rctxid = detach->context_id; + + pr_debug("%s: ctxid=%llu\n", __func__, ctxid); + + if (!ctxi) { + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%llu)\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + unlock_ctx = true; + } + + /* Cleanup outstanding resources tied to this LUN */ + if (ctxi->rht_out) { + marshal_det_to_rele(detach, &rel); + for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) { + if (ctxi->rht_lun[i] == lli) { + rel.rsrc_handle = i; + _cxlflash_disk_release(sdev, ctxi, &rel); + } + + /* No need to loop further if we're done */ + if (ctxi->rht_out == 0) + break; + } + } + + /* Take our LUN out of context, free the node */ + list_for_each_entry_safe(lun_access, t, &ctxi->luns, list) + if (lun_access->lli == lli) { + list_del(&lun_access->list); + kfree(lun_access); + lun_access = NULL; + break; + } + + /* Tear down context following last LUN cleanup */ + if (list_empty(&ctxi->luns)) { + mutex_lock(&cfg->ctx_tbl_list_mutex); + + /* Might not have been in error list so conditionally remove */ + if (!list_empty(&ctxi->list)) + list_del(&ctxi->list); + cfg->ctx_tbl[ctxid] = NULL; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + mutex_unlock(&ctxi->mutex); + + lfd = ctxi->lfd; + destroy_context(cfg, ctxi); + ctxi = NULL; + unlock_ctx = false; + + /* + * As a last step, clean up external resources when not + * already on an external cleanup thread, ie: close(adap_fd). + * + * NOTE: this will free up the context from the CXL services, + * allowing it to dole out the same context_id on a future + * (or even currently in-flight) disk_attach operation. + */ + if (lfd != -1) + sys_close(lfd); + } + +out: + if (unlock_ctx) + mutex_unlock(&ctxi->mutex); + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; +} + +static int cxlflash_disk_detach(struct scsi_device *sdev, + struct dk_cxlflash_detach *detach) +{ + return _cxlflash_disk_detach(sdev, NULL, detach); +} + +/** + * cxlflash_cxl_release() - release handler for adapter file descriptor + * @inode: Filesystem inode associated with fd. + * @file: File installed with adapter file descriptor. + * + * This routine is the release handler for the fops registered with + * the CXL services on an initial attach for a context. It is called + * when a close is performed on the adapter file descriptor returned + * to the user. Programmatically, the user is not required to perform + * the close, as it is handled internally via the detach ioctl when + * a context is being removed. Note that nothing prevents the user + * from performing a close, but the user should be aware that doing + * so is considered catastrophic and subsequent usage of the superpipe + * API with previously saved off tokens will fail. + * + * When initiated from an external close (either by the user or via + * a process tear down), the routine derives the context reference + * and calls detach for each LUN associated with the context. The + * final detach operation will cause the context itself to be freed. + * Note that the saved off lfd is reset prior to calling detach to + * signify that the final detach should not perform a close. + * + * When initiated from a detach operation as part of the tear down + * of a context, the context is first completely freed and then the + * close is performed. This routine will fail to derive the context + * reference (due to the context having already been freed) and then + * call into the CXL release entry point. + * + * Thus, with exception to when the CXL process element (context id) + * lookup fails (a case that should theoretically never occur), every + * call into this routine results in a complete freeing of a context. + * + * As part of the detach, all per-context resources associated with the LUN + * are cleaned up. When detaching the last LUN for a context, the context + * itself is cleaned up and released. + * + * Return: 0 on success + */ +static int cxlflash_cxl_release(struct inode *inode, struct file *file) +{ + struct cxl_context *ctx = cxl_fops_get_context(file); + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + struct ctx_info *ctxi = NULL; + struct dk_cxlflash_detach detach = { { 0 }, 0 }; + struct lun_access *lun_access, *t; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + int ctxid; + + ctxid = cxl_process_element(ctx); + if (unlikely(ctxid < 0)) { + pr_err("%s: Context %p was closed! (%d)\n", + __func__, ctx, ctxid); + goto out; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + ctxi = get_context(cfg, ctxid, file, ctrl | CTX_CTRL_CLONE); + if (!ctxi) { + pr_debug("%s: Context %d already free!\n", + __func__, ctxid); + goto out_release; + } + + pr_debug("%s: Another process owns context %d!\n", + __func__, ctxid); + mutex_unlock(&ctxi->mutex); + goto out; + } + + pr_debug("%s: close(%d) for context %d\n", + __func__, ctxi->lfd, ctxid); + + /* Reset the file descriptor to indicate we're on a close() thread */ + ctxi->lfd = -1; + detach.context_id = ctxi->ctxid; + list_for_each_entry_safe(lun_access, t, &ctxi->luns, list) + _cxlflash_disk_detach(lun_access->sdev, ctxi, &detach); +out_release: + cxl_fd_release(inode, file); +out: + pr_debug("%s: returning\n", __func__); + return 0; +} + +/** + * unmap_context() - clears a previously established mapping + * @ctxi: Context owning the mapping. + * + * This routine is used to switch between the error notification page + * (dummy page of all 1's) and the real mapping (established by the CXL + * fault handler). + */ +static void unmap_context(struct ctx_info *ctxi) +{ + unmap_mapping_range(ctxi->file->f_mapping, 0, 0, 1); +} + +/** + * get_err_page() - obtains and allocates the error notification page + * + * Return: error notification page on success, NULL on failure + */ +static struct page *get_err_page(void) +{ + struct page *err_page = global.err_page; + ulong flags = 0; + + if (unlikely(!err_page)) { + err_page = alloc_page(GFP_KERNEL); + if (unlikely(!err_page)) { + pr_err("%s: Unable to allocate err_page!\n", __func__); + goto out; + } + + memset(page_address(err_page), -1, PAGE_SIZE); + + /* Serialize update w/ other threads to avoid a leak */ + spin_lock_irqsave(&global.slock, flags); + if (likely(!global.err_page)) + global.err_page = err_page; + else { + __free_page(err_page); + err_page = global.err_page; + } + spin_unlock_irqrestore(&global.slock, flags); + } + +out: + pr_debug("%s: returning err_page=%p\n", __func__, err_page); + return err_page; +} + +/** + * cxlflash_mmap_fault() - mmap fault handler for adapter file descriptor + * @vma: VM area associated with mapping. + * @vmf: VM fault associated with current fault. + * + * To support error notification via MMIO, faults are 'caught' by this routine + * that was inserted before passing back the adapter file descriptor on attach. + * When a fault occurs, this routine evaluates if error recovery is active and + * if so, installs the error page to 'notify' the user about the error state. + * During normal operation, the fault is simply handled by the original fault + * handler that was installed by CXL services as part of initializing the + * adapter file descriptor. + * + * Return: 0 on success, VM_FAULT_SIGBUS on failure + */ +static int cxlflash_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct file *file = vma->vm_file; + struct cxl_context *ctx = cxl_fops_get_context(file); + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + struct ctx_info *ctxi = NULL; + struct page *err_page = NULL; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + int rc = 0; + int ctxid; + + ctxid = cxl_process_element(ctx); + if (unlikely(ctxid < 0)) { + pr_err("%s: Context %p was closed! (%d)\n", + __func__, ctx, ctxid); + goto err; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%d)\n", __func__, ctxid); + goto err; + } + + pr_debug("%s: fault(%d) for context %d\n", + __func__, ctxi->lfd, ctxid); + + if (likely(!ctxi->err_recovery_active)) + rc = ctxi->cxl_mmap_vmops->fault(vma, vmf); + else { + pr_debug("%s: err recovery active, use err_page!\n", __func__); + + err_page = get_err_page(); + if (unlikely(!err_page)) { + pr_err("%s: Could not obtain error page!\n", __func__); + rc = VM_FAULT_RETRY; + goto out; + } + + get_page(err_page); + vmf->page = err_page; + } + +out: + if (likely(ctxi)) + mutex_unlock(&ctxi->mutex); + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; + +err: + rc = VM_FAULT_SIGBUS; + goto out; +} + +/* + * Local MMAP vmops to 'catch' faults + */ +static const struct vm_operations_struct cxlflash_mmap_vmops = { + .fault = cxlflash_mmap_fault, +}; + +/** + * cxlflash_cxl_mmap() - mmap handler for adapter file descriptor + * @file: File installed with adapter file descriptor. + * @vma: VM area associated with mapping. + * + * Installs local mmap vmops to 'catch' faults for error notification support. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_cxl_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct cxl_context *ctx = cxl_fops_get_context(file); + struct cxlflash_cfg *cfg = container_of(file->f_op, struct cxlflash_cfg, + cxl_fops); + struct ctx_info *ctxi = NULL; + enum ctx_ctrl ctrl = CTX_CTRL_ERR_FALLBACK | CTX_CTRL_FILE; + int ctxid; + int rc = 0; + + ctxid = cxl_process_element(ctx); + if (unlikely(ctxid < 0)) { + pr_err("%s: Context %p was closed! (%d)\n", + __func__, ctx, ctxid); + rc = -EIO; + goto out; + } + + ctxi = get_context(cfg, ctxid, file, ctrl); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%d)\n", __func__, ctxid); + rc = -EIO; + goto out; + } + + pr_debug("%s: mmap(%d) for context %d\n", __func__, ctxi->lfd, ctxid); + + rc = cxl_fd_mmap(file, vma); + if (likely(!rc)) { + /* Insert ourself in the mmap fault handler path */ + ctxi->cxl_mmap_vmops = vma->vm_ops; + vma->vm_ops = &cxlflash_mmap_vmops; + } + +out: + if (likely(ctxi)) + mutex_unlock(&ctxi->mutex); + return rc; +} + +/* + * Local fops for adapter file descriptor + */ +static const struct file_operations cxlflash_cxl_fops = { + .owner = THIS_MODULE, + .mmap = cxlflash_cxl_mmap, + .release = cxlflash_cxl_release, +}; + +/** + * cxlflash_mark_contexts_error() - move contexts to error state and list + * @cfg: Internal structure associated with the host. + * + * A context is only moved over to the error list when there are no outstanding + * references to it. This ensures that a running operation has completed. After + * marking all contexts in error, the CPU is scheduled to allow user threads + * time to respond to the freshly installed error page. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg) +{ + int i, rc = 0; + struct ctx_info *ctxi = NULL; + + mutex_lock(&cfg->ctx_tbl_list_mutex); + + for (i = 0; i < MAX_CONTEXT; i++) { + ctxi = cfg->ctx_tbl[i]; + if (ctxi) { + mutex_lock(&ctxi->mutex); + cfg->ctx_tbl[i] = NULL; + list_add(&ctxi->list, &cfg->ctx_err_recovery); + ctxi->err_recovery_active = true; + ctxi->ctrl_map = NULL; + unmap_context(ctxi); + mutex_unlock(&ctxi->mutex); + } + } + + mutex_unlock(&cfg->ctx_tbl_list_mutex); + schedule(); + return rc; +} + +/* + * Dummy NULL fops + */ +static const struct file_operations null_fops = { + .owner = THIS_MODULE, +}; + +/** + * cxlflash_disk_attach() - attach a LUN to a context + * @sdev: SCSI device associated with LUN. + * @attach: Attach ioctl data structure. + * + * Creates a context and attaches LUN to it. A LUN can only be attached + * one time to a context (subsequent attaches for the same context/LUN pair + * are not supported). Additional LUNs can be attached to a context by + * specifying the 'reuse' flag defined in the cxlflash_ioctl.h header. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_attach(struct scsi_device *sdev, + struct dk_cxlflash_attach *attach) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct afu *afu = cfg->afu; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct cxl_ioctl_start_work *work; + struct ctx_info *ctxi = NULL; + struct lun_access *lun_access = NULL; + int rc = 0; + u32 perms; + int ctxid = -1; + u64 rctxid = 0UL; + struct file *file; + + struct cxl_context *ctx; + + int fd = -1; + + /* On first attach set fileops */ + if (atomic_read(&cfg->num_user_contexts) == 0) + cfg->cxl_fops = cxlflash_cxl_fops; + + if (attach->num_interrupts > 4) { + pr_err("%s: Cannot support this many interrupts %llu\n", + __func__, attach->num_interrupts); + rc = -EINVAL; + goto out; + } + + if (gli->max_lba == 0) { + pr_debug("%s: No capacity info yet for this LUN (%016llX)\n", + __func__, lli->lun_id[sdev->channel]); + rc = read_cap16(sdev, lli); + if (rc) { + pr_err("%s: Invalid device! (%d)\n", __func__, rc); + rc = -ENODEV; + goto out; + } + pr_debug("%s: LBA = %016llX\n", __func__, gli->max_lba); + pr_debug("%s: BLK_LEN = %08X\n", __func__, gli->blk_len); + } + + if (attach->hdr.flags & DK_CXLFLASH_ATTACH_REUSE_CONTEXT) { + rctxid = attach->context_id; + ctxi = get_context(cfg, rctxid, NULL, 0); + if (!ctxi) { + pr_err("%s: Bad context! (%016llX)\n", + __func__, rctxid); + rc = -EINVAL; + goto out; + } + + list_for_each_entry(lun_access, &ctxi->luns, list) + if (lun_access->lli == lli) { + pr_err("%s: Already attached!\n", __func__); + rc = -EINVAL; + goto out; + } + } + + lun_access = kzalloc(sizeof(*lun_access), GFP_KERNEL); + if (unlikely(!lun_access)) { + pr_err("%s: Unable to allocate lun_access!\n", __func__); + rc = -ENOMEM; + goto out; + } + + lun_access->lli = lli; + lun_access->sdev = sdev; + + /* Non-NULL context indicates reuse */ + if (ctxi) { + pr_debug("%s: Reusing context for LUN! (%016llX)\n", + __func__, rctxid); + list_add(&lun_access->list, &ctxi->luns); + fd = ctxi->lfd; + goto out_attach; + } + + ctx = cxl_dev_context_init(cfg->dev); + if (unlikely(IS_ERR_OR_NULL(ctx))) { + pr_err("%s: Could not initialize context %p\n", __func__, ctx); + rc = -ENODEV; + goto err0; + } + + ctxid = cxl_process_element(ctx); + if (unlikely((ctxid > MAX_CONTEXT) || (ctxid < 0))) { + pr_err("%s: ctxid (%d) invalid!\n", __func__, ctxid); + rc = -EPERM; + goto err1; + } + + file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd); + if (unlikely(fd < 0)) { + rc = -ENODEV; + pr_err("%s: Could not get file descriptor\n", __func__); + goto err1; + } + + /* Translate read/write O_* flags from fcntl.h to AFU permission bits */ + perms = SISL_RHT_PERM(attach->hdr.flags + 1); + + ctxi = create_context(cfg, ctx, ctxid, fd, file, perms); + if (unlikely(!ctxi)) { + pr_err("%s: Failed to create context! (%d)\n", __func__, ctxid); + goto err2; + } + + work = &ctxi->work; + work->num_interrupts = attach->num_interrupts; + work->flags = CXL_START_WORK_NUM_IRQS; + + rc = cxl_start_work(ctx, work); + if (unlikely(rc)) { + pr_debug("%s: Could not start context rc=%d\n", __func__, rc); + goto err3; + } + + rc = afu_attach(cfg, ctxi); + if (unlikely(rc)) { + pr_err("%s: Could not attach AFU rc %d\n", __func__, rc); + goto err4; + } + + /* + * No error paths after this point. Once the fd is installed it's + * visible to user space and can't be undone safely on this thread. + */ + list_add(&lun_access->list, &ctxi->luns); + mutex_lock(&cfg->ctx_tbl_list_mutex); + cfg->ctx_tbl[ctxid] = ctxi; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + fd_install(fd, file); + +out_attach: + attach->hdr.return_flags = 0; + attach->context_id = ctxi->ctxid; + attach->block_size = gli->blk_len; + attach->mmio_size = sizeof(afu->afu_map->hosts[0].harea); + attach->last_lba = gli->max_lba; + attach->max_xfer = (sdev->host->max_sectors * 512) / gli->blk_len; + +out: + attach->adap_fd = fd; + + if (ctxi) + mutex_unlock(&ctxi->mutex); + + pr_debug("%s: returning ctxid=%d fd=%d bs=%lld rc=%d llba=%lld\n", + __func__, ctxid, fd, attach->block_size, rc, attach->last_lba); + return rc; + +err4: + cxl_stop_context(ctx); +err3: + destroy_context(cfg, ctxi); +err2: + /* + * Here, we're overriding the fops with a dummy all-NULL fops because + * fput() calls the release fop, which will cause us to mistakenly + * call into the CXL code. Rather than try to add yet more complexity + * to that routine (cxlflash_cxl_release) we should try to fix the + * issue here. + */ + file->f_op = &null_fops; + fput(file); + put_unused_fd(fd); + fd = -1; +err1: + cxl_release_context(ctx); +err0: + kfree(lun_access); + goto out; +} + +/** + * cxlflash_manage_lun() - handles lun management activities + * @sdev: SCSI device associated with LUN. + * @manage: Manage ioctl data structure. + * + * This routine is used to notify the driver about a LUN's WWID and associate + * SCSI devices (sdev) with a global LUN instance. Additionally it serves to + * change a LUN's operating mode: legacy or superpipe. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_manage_lun(struct scsi_device *sdev, + struct dk_cxlflash_manage_lun *manage) +{ + int rc = 0; + struct llun_info *lli = NULL; + u64 flags = manage->hdr.flags; + u32 chan = sdev->channel; + + lli = lookup_lun(sdev, manage->wwid); + pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n", + __func__, get_unaligned_le64(&manage->wwid[0]), + get_unaligned_le64(&manage->wwid[8]), + manage->hdr.flags, lli); + if (unlikely(!lli)) { + rc = -ENOMEM; + goto out; + } + + if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) { + if (lli->newly_created) + lli->port_sel = CHAN2PORT(chan); + else + lli->port_sel = BOTH_PORTS; + /* Store off lun in unpacked, AFU-friendly format */ + lli->lun_id[chan] = lun_to_lunid(sdev->lun); + sdev->hostdata = lli; + } else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) { + if (lli->parent->mode != MODE_NONE) + rc = -EBUSY; + else + sdev->hostdata = NULL; + } + +out: + pr_debug("%s: returning rc=%d\n", __func__, rc); + return rc; +} + +/** + * recover_context() - recovers a context in error + * @cfg: Internal structure associated with the host. + * @ctxi: Context to release. + * + * Restablishes the state for a context-in-error. + * + * Return: 0 on success, -errno on failure + */ +static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) +{ + int rc = 0; + int old_fd, fd = -1; + int ctxid = -1; + struct file *file; + struct cxl_context *ctx; + struct afu *afu = cfg->afu; + + ctx = cxl_dev_context_init(cfg->dev); + if (unlikely(IS_ERR_OR_NULL(ctx))) { + pr_err("%s: Could not initialize context %p\n", __func__, ctx); + rc = -ENODEV; + goto out; + } + + ctxid = cxl_process_element(ctx); + if (unlikely((ctxid > MAX_CONTEXT) || (ctxid < 0))) { + pr_err("%s: ctxid (%d) invalid!\n", __func__, ctxid); + rc = -EPERM; + goto err1; + } + + file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd); + if (unlikely(fd < 0)) { + rc = -ENODEV; + pr_err("%s: Could not get file descriptor\n", __func__); + goto err1; + } + + rc = cxl_start_work(ctx, &ctxi->work); + if (unlikely(rc)) { + pr_err("%s: Could not start context rc=%d\n", __func__, rc); + goto err2; + } + + /* Update with new MMIO area based on updated context id */ + ctxi->ctrl_map = &afu->afu_map->ctrls[ctxid].ctrl; + + rc = afu_attach(cfg, ctxi); + if (rc) { + pr_err("%s: Could not attach AFU rc %d\n", __func__, rc); + goto err3; + } + + /* + * No error paths after this point. Once the fd is installed it's + * visible to user space and can't be undone safely on this thread. + */ + old_fd = ctxi->lfd; + ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid); + ctxi->lfd = fd; + ctxi->ctx = ctx; + ctxi->file = file; + + /* Put context back in table (note the reinit of the context list) */ + mutex_lock(&cfg->ctx_tbl_list_mutex); + list_del_init(&ctxi->list); + cfg->ctx_tbl[ctxid] = ctxi; + mutex_unlock(&cfg->ctx_tbl_list_mutex); + fd_install(fd, file); + + /* Release the original adapter fd and associated CXL resources */ + sys_close(old_fd); +out: + pr_debug("%s: returning ctxid=%d fd=%d rc=%d\n", + __func__, ctxid, fd, rc); + return rc; + +err3: + cxl_stop_context(ctx); +err2: + fput(file); + put_unused_fd(fd); +err1: + cxl_release_context(ctx); + goto out; +} + +/** + * check_eeh() - checks and responds to the current EEH state + * @cfg: Internal structure associated with the host. + * + * This routine can block and should only be used on process context. + * Note that when waking up from waiting on the EEH event to clear, + * the state must be checked again in case another EEH has occurred or + * the previous event failed recovery. + * + * Return: 0 on success, -errno on failure + */ +static int check_eeh(struct cxlflash_cfg *cfg) +{ + int rc = 0; + +retry: + switch (cfg->eeh_active) { + case EEH_STATE_ACTIVE: + pr_debug("%s: EEH Active, going to wait...\n", __func__); + rc = wait_event_interruptible(cfg->eeh_waitq, + cfg->eeh_active != + EEH_STATE_ACTIVE); + if (unlikely(rc)) + goto out; + goto retry; + case EEH_STATE_FAILED: + pr_debug("%s: EEH Failed\n", __func__); + rc = -ENODEV; + goto out; + case EEH_STATE_NONE: + break; + } +out: + return rc; +} + +/** + * cxlflash_afu_recover() - initiates AFU recovery + * @sdev: SCSI device associated with LUN. + * @recover: Recover ioctl data structure. + * + * Because a user can detect an error condition before the kernel, it is + * quite possible for this routine to act as the kernel's EEH detection + * source (MMIO read of mbox_r). Because of this, there is a window of + * time where an EEH might have been detected but not yet 'serviced' + * (callback invoked, causing the EEH state to flip). To avoid looping + * in this routine during that window, a 1 second sleep is in place + * between the time the MMIO failure is detected and the time a wait + * on the EEH wait queue is attempted. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_afu_recover(struct scsi_device *sdev, + struct dk_cxlflash_recover_afu *recover) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct llun_info *lli = sdev->hostdata; + struct afu *afu = cfg->afu; + struct ctx_info *ctxi = NULL; + u64 ctxid = DECODE_CTXID(recover->context_id), + rctxid = recover->context_id; + long reg; + int rc = 0; + + pr_debug("%s: reason 0x%016llX rctxid=%016llX\n", __func__, + recover->reason, rctxid); + +retry: + /* Ensure that this process is attached to the context */ + ctxi = get_context(cfg, rctxid, lli, CTX_CTRL_ERR_FALLBACK); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%llu)\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + if (ctxi->err_recovery_active) { + rc = recover_context(cfg, ctxi); + if (unlikely(rc)) { + pr_err("%s: Recovery failed for context %llu (rc=%d)\n", + __func__, ctxid, rc); + goto out; + } + + ctxi->err_recovery_active = false; + recover->context_id = ctxi->ctxid; + recover->adap_fd = ctxi->lfd; + recover->mmio_size = sizeof(afu->afu_map->hosts[0].harea); + recover->hdr.return_flags |= + DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET; + goto out; + } + + /* Test if in error state */ + reg = readq_be(&afu->ctrl_map->mbox_r); + if (reg == -1) { + pr_info("%s: MMIO read fail! Wait for recovery...\n", __func__); + mutex_unlock(&ctxi->mutex); + ctxi = NULL; + ssleep(1); + rc = check_eeh(cfg); + if (unlikely(rc)) + goto out; + goto retry; + } + + pr_debug("%s: MMIO working, no recovery required!\n", __func__); +out: + if (likely(ctxi)) + mutex_unlock(&ctxi->mutex); + return rc; +} + +/** + * process_sense() - evaluates and processes sense data + * @sdev: SCSI device associated with LUN. + * @verify: Verify ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +static int process_sense(struct scsi_device *sdev, + struct dk_cxlflash_verify *verify) +{ + struct request_sense_data *sense_data = (struct request_sense_data *) + &verify->sense_data; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + u64 prev_lba = gli->max_lba; + int rc = 0; + + switch (sense_data->sense_key) { + case NO_SENSE: + case RECOVERED_ERROR: + /* fall through */ + case NOT_READY: + break; + case UNIT_ATTENTION: + switch (sense_data->add_sense_key) { + case 0x29: /* Power on Reset or Device Reset */ + /* fall through */ + case 0x2A: /* Device settings/capacity changed */ + rc = read_cap16(sdev, lli); + if (rc) { + rc = -ENODEV; + break; + } + if (prev_lba != gli->max_lba) + pr_debug("%s: Capacity changed old=%lld " + "new=%lld\n", __func__, prev_lba, + gli->max_lba); + break; + case 0x3F: /* Report LUNs changed, Rescan. */ + scsi_scan_host(cfg->host); + break; + default: + rc = -EIO; + break; + } + break; + default: + rc = -EIO; + break; + } + pr_debug("%s: sense_key %x asc %x rc %d\n", __func__, + sense_data->sense_key, sense_data->add_sense_key, rc); + return rc; +} + +/** + * cxlflash_disk_verify() - verifies a LUN is the same and handle size changes + * @sdev: SCSI device associated with LUN. + * @verify: Verify ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_verify(struct scsi_device *sdev, + struct dk_cxlflash_verify *verify) +{ + int rc = 0; + struct ctx_info *ctxi = NULL; + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + struct sisl_rht_entry *rhte = NULL; + res_hndl_t rhndl = verify->rsrc_handle; + u64 ctxid = DECODE_CTXID(verify->context_id), + rctxid = verify->context_id; + u64 last_lba = 0; + + pr_debug("%s: ctxid=%llu rhndl=0x%llx, hint=0x%llx\n", + __func__, ctxid, verify->rsrc_handle, verify->hint); + + ctxi = get_context(cfg, rctxid, lli, 0); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%llu)\n", __func__, ctxid); + rc = -EINVAL; + goto out; + } + + rhte = get_rhte(ctxi, rhndl, lli); + if (unlikely(!rhte)) { + pr_err("%s: Bad resource handle! (%d)\n", __func__, rhndl); + rc = -EINVAL; + goto out; + } + + /* + * Look at the hint/sense to see if it requires us to redrive + * inquiry (i.e. the Unit attention is due to the WWN changing). + */ + if (verify->hint & DK_CXLFLASH_VERIFY_HINT_SENSE) { + rc = process_sense(sdev, verify); + if (unlikely(rc)) { + pr_err("%s: Failed to validate sense data! (%d)\n", + __func__, rc); + goto out; + } + } + + switch (gli->mode) { + case MODE_PHYSICAL: + last_lba = gli->max_lba; + break; + default: + BUG(); + } + + verify->last_lba = last_lba; + +out: + if (likely(ctxi)) + mutex_unlock(&ctxi->mutex); + pr_debug("%s: returning rc=%d llba=%lld\n", + __func__, rc, verify->last_lba); + return rc; +} + +/** + * decode_ioctl() - translates an encoded ioctl to an easily identifiable string + * @cmd: The ioctl command to decode. + * + * Return: A string identifying the decoded ioctl. + */ +static char *decode_ioctl(int cmd) +{ + switch (cmd) { + case DK_CXLFLASH_ATTACH: + return __stringify_1(DK_CXLFLASH_ATTACH); + case DK_CXLFLASH_USER_DIRECT: + return __stringify_1(DK_CXLFLASH_USER_DIRECT); + case DK_CXLFLASH_RELEASE: + return __stringify_1(DK_CXLFLASH_RELEASE); + case DK_CXLFLASH_DETACH: + return __stringify_1(DK_CXLFLASH_DETACH); + case DK_CXLFLASH_VERIFY: + return __stringify_1(DK_CXLFLASH_VERIFY); + case DK_CXLFLASH_RECOVER_AFU: + return __stringify_1(DK_CXLFLASH_RECOVER_AFU); + case DK_CXLFLASH_MANAGE_LUN: + return __stringify_1(DK_CXLFLASH_MANAGE_LUN); + } + + return "UNKNOWN"; +} + +/** + * cxlflash_disk_direct_open() - opens a direct (physical) disk + * @sdev: SCSI device associated with LUN. + * @arg: UDirect ioctl data structure. + * + * On successful return, the user is informed of the resource handle + * to be used to identify the direct lun and the size (in blocks) of + * the direct lun in last LBA format. + * + * Return: 0 on success, -errno on failure + */ +static int cxlflash_disk_direct_open(struct scsi_device *sdev, void *arg) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct afu *afu = cfg->afu; + struct llun_info *lli = sdev->hostdata; + struct glun_info *gli = lli->parent; + + struct dk_cxlflash_udirect *pphys = (struct dk_cxlflash_udirect *)arg; + + u64 ctxid = DECODE_CTXID(pphys->context_id), + rctxid = pphys->context_id; + u64 lun_size = 0; + u64 last_lba = 0; + u64 rsrc_handle = -1; + u32 port = CHAN2PORT(sdev->channel); + + int rc = 0; + + struct ctx_info *ctxi = NULL; + struct sisl_rht_entry *rhte = NULL; + + pr_debug("%s: ctxid=%llu ls=0x%llx\n", __func__, ctxid, lun_size); + + rc = cxlflash_lun_attach(gli, MODE_PHYSICAL); + if (unlikely(rc)) { + pr_err("%s: Failed to attach to LUN! (PHYSICAL)\n", __func__); + goto out; + } + + ctxi = get_context(cfg, rctxid, lli, 0); + if (unlikely(!ctxi)) { + pr_err("%s: Bad context! (%llu)\n", __func__, ctxid); + rc = -EINVAL; + goto err1; + } + + rhte = rhte_checkout(ctxi, lli); + if (unlikely(!rhte)) { + pr_err("%s: too many opens for this context\n", __func__); + rc = -EMFILE; /* too many opens */ + goto err1; + } + + rsrc_handle = (rhte - ctxi->rht_start); + + rht_format1(rhte, lli->lun_id[sdev->channel], ctxi->rht_perms, port); + cxlflash_afu_sync(afu, ctxid, rsrc_handle, AFU_LW_SYNC); + + last_lba = gli->max_lba; + pphys->hdr.return_flags = 0; + pphys->last_lba = last_lba; + pphys->rsrc_handle = rsrc_handle; + +out: + if (likely(ctxi)) + mutex_unlock(&ctxi->mutex); + pr_debug("%s: returning handle 0x%llx rc=%d llba %lld\n", + __func__, rsrc_handle, rc, last_lba); + return rc; + +err1: + cxlflash_lun_detach(gli); + goto out; +} + +/** + * ioctl_common() - common IOCTL handler for driver + * @sdev: SCSI device associated with LUN. + * @cmd: IOCTL command. + * + * Handles common fencing operations that are valid for multiple ioctls. In + * the event of an EEH failure, allow through ioctls that are cleanup oriented + * in nature. + * + * Return: 0 on success, -errno on failure + */ +static int ioctl_common(struct scsi_device *sdev, int cmd) +{ + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct llun_info *lli = sdev->hostdata; + int rc = 0; + + if (unlikely(!lli)) { + pr_debug("%s: Unknown LUN\n", __func__); + rc = -EINVAL; + goto out; + } + + rc = check_eeh(cfg); + if (unlikely(rc) && (cfg->eeh_active == EEH_STATE_FAILED)) { + switch (cmd) { + case DK_CXLFLASH_VLUN_RESIZE: + case DK_CXLFLASH_RELEASE: + case DK_CXLFLASH_DETACH: + pr_debug("%s: Command override! (%d)\n", __func__, rc); + rc = 0; + break; + } + } +out: + return rc; +} + +/** + * cxlflash_ioctl() - IOCTL handler for driver + * @sdev: SCSI device associated with LUN. + * @cmd: IOCTL command. + * @arg: Userspace ioctl data structure. + * + * Return: 0 on success, -errno on failure + */ +int cxlflash_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) +{ + typedef int (*sioctl) (struct scsi_device *, void *); + + struct cxlflash_cfg *cfg = (struct cxlflash_cfg *)sdev->host->hostdata; + struct afu *afu = cfg->afu; + struct dk_cxlflash_hdr *hdr; + char buf[MAX_CXLFLASH_IOCTL_SZ]; + size_t size = 0; + bool known_ioctl = false; + int idx; + int rc = 0; + struct Scsi_Host *shost = sdev->host; + sioctl do_ioctl = NULL; + + static const struct { + size_t size; + sioctl ioctl; + } ioctl_tbl[] = { /* NOTE: order matters here */ + {sizeof(struct dk_cxlflash_attach), (sioctl)cxlflash_disk_attach}, + {sizeof(struct dk_cxlflash_udirect), cxlflash_disk_direct_open}, + {sizeof(struct dk_cxlflash_release), (sioctl)cxlflash_disk_release}, + {sizeof(struct dk_cxlflash_detach), (sioctl)cxlflash_disk_detach}, + {sizeof(struct dk_cxlflash_verify), (sioctl)cxlflash_disk_verify}, + {sizeof(struct dk_cxlflash_recover_afu), (sioctl)cxlflash_afu_recover}, + {sizeof(struct dk_cxlflash_manage_lun), (sioctl)cxlflash_manage_lun}, + }; + + /* Restrict command set to physical support only for internal LUN */ + if (afu->internal_lun) + switch (cmd) { + case DK_CXLFLASH_RELEASE: + pr_err("%s: %s not supported for lun_mode=%d\n", + __func__, decode_ioctl(cmd), afu->internal_lun); + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + switch (cmd) { + case DK_CXLFLASH_ATTACH: + case DK_CXLFLASH_USER_DIRECT: + case DK_CXLFLASH_RELEASE: + case DK_CXLFLASH_DETACH: + case DK_CXLFLASH_VERIFY: + case DK_CXLFLASH_RECOVER_AFU: + pr_debug("%s: %s (%08X) on dev(%d/%d/%d/%llu)\n", __func__, + decode_ioctl(cmd), cmd, shost->host_no, sdev->channel, + sdev->id, sdev->lun); + rc = ioctl_common(sdev, cmd); + if (unlikely(rc)) + goto cxlflash_ioctl_exit; + + /* fall through */ + + case DK_CXLFLASH_MANAGE_LUN: + known_ioctl = true; + idx = _IOC_NR(cmd) - _IOC_NR(DK_CXLFLASH_ATTACH); + size = ioctl_tbl[idx].size; + do_ioctl = ioctl_tbl[idx].ioctl; + + if (likely(do_ioctl)) + break; + + /* fall through */ + default: + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + if (unlikely(copy_from_user(&buf, arg, size))) { + pr_err("%s: copy_from_user() fail! " + "size=%lu cmd=%d (%s) arg=%p\n", + __func__, size, cmd, decode_ioctl(cmd), arg); + rc = -EFAULT; + goto cxlflash_ioctl_exit; + } + + hdr = (struct dk_cxlflash_hdr *)&buf; + if (hdr->version != 0) { + pr_err("%s: Version %u not supported for %s\n", + __func__, hdr->version, decode_ioctl(cmd)); + rc = -EINVAL; + goto cxlflash_ioctl_exit; + } + + rc = do_ioctl(sdev, (void *)&buf); + if (likely(!rc)) + if (unlikely(copy_to_user(arg, &buf, size))) { + pr_err("%s: copy_to_user() fail! " + "size=%lu cmd=%d (%s) arg=%p\n", + __func__, size, cmd, decode_ioctl(cmd), arg); + rc = -EFAULT; + } + + /* fall through to exit */ + +cxlflash_ioctl_exit: + if (unlikely(rc && known_ioctl)) + pr_err("%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) " + "returned rc %d\n", __func__, + decode_ioctl(cmd), cmd, shost->host_no, + sdev->channel, sdev->id, sdev->lun, rc); + else + pr_debug("%s: ioctl %s (%08X) on dev(%d/%d/%d/%llu) " + "returned rc %d\n", __func__, decode_ioctl(cmd), + cmd, shost->host_no, sdev->channel, sdev->id, + sdev->lun, rc); + return rc; +} + diff --git a/drivers/scsi/cxlflash/superpipe.h b/drivers/scsi/cxlflash/superpipe.h new file mode 100644 index 0000000..6166527 --- /dev/null +++ b/drivers/scsi/cxlflash/superpipe.h @@ -0,0 +1,142 @@ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _CXLFLASH_SUPERPIPE_H +#define _CXLFLASH_SUPERPIPE_H + +#define MC_DISCOVERY_TIMEOUT 5 /* 5 secs */ + +#define CHAN2PORT(_x) ((_x) + 1) +#define PORT2CHAN(_x) ((_x) - 1) + +enum lun_mode { + MODE_NONE = 0, + MODE_PHYSICAL +}; + +/* SCSI Defines */ + +struct request_sense_data { + uint8_t err_code; /* error class and code */ + uint8_t rsvd0; + uint8_t sense_key; +#define CXLFLASH_VENDOR_UNIQUE 0x09 +#define CXLFLASH_EQUAL_CMD 0x0C + uint8_t sense_byte0; + uint8_t sense_byte1; + uint8_t sense_byte2; + uint8_t sense_byte3; + uint8_t add_sense_length; + uint8_t add_sense_byte0; + uint8_t add_sense_byte1; + uint8_t add_sense_byte2; + uint8_t add_sense_byte3; + uint8_t add_sense_key; + uint8_t add_sense_qualifier; + uint8_t fru; + uint8_t flag_byte; + uint8_t field_ptrM; + uint8_t field_ptrL; +}; + +/* Global (entire driver, spans adapters) lun_info structure */ +struct glun_info { + u64 max_lba; /* from read cap(16) */ + u32 blk_len; /* from read cap(16) */ + enum lun_mode mode; /* NONE, PHYSICAL */ + int users; /* Number of users w/ references to LUN */ + + u8 wwid[16]; + + spinlock_t slock; + + struct list_head list; +}; + +/* Local (per-adapter) lun_info structure */ +struct llun_info { + u64 lun_id[CXLFLASH_NUM_FC_PORTS]; /* from REPORT_LUNS */ + u32 host_no; /* host_no from Scsi_host */ + u32 port_sel; /* What port to use for this LUN */ + bool newly_created; /* Whether the LUN was just discovered */ + bool in_table; /* Whether a LUN table entry was created */ + + u8 wwid[16]; /* Keep a duplicate copy here? */ + + struct glun_info *parent; /* Pointer to entry in global lun structure */ + struct scsi_device *sdev; + struct list_head list; +}; + +struct lun_access { + struct llun_info *lli; + struct scsi_device *sdev; + struct list_head list; +}; + +enum ctx_ctrl { + CTX_CTRL_CLONE = (1 << 1), + CTX_CTRL_ERR = (1 << 2), + CTX_CTRL_ERR_FALLBACK = (1 << 3), + CTX_CTRL_NOPID = (1 << 4), + CTX_CTRL_FILE = (1 << 5) +}; + +#define ENCODE_CTXID(_ctx, _id) (((((u64)_ctx) & 0xFFFFFFFF0) << 28) | _id) +#define DECODE_CTXID(_val) (_val & 0xFFFFFFFF) + +struct ctx_info { + struct sisl_ctrl_map *ctrl_map; /* initialized at startup */ + struct sisl_rht_entry *rht_start; /* 1 page (req'd for alignment), + alloc/free on attach/detach */ + u32 rht_out; /* Number of checked out RHT entries */ + u32 rht_perms; /* User-defined permissions for RHT entries */ + struct llun_info **rht_lun; /* Mapping of RHT entries to LUNs */ + + struct cxl_ioctl_start_work work; + u64 ctxid; + int lfd; + pid_t pid; + bool err_recovery_active; + struct mutex mutex; /* Context protection */ + struct cxl_context *ctx; + struct list_head luns; /* LUNs attached to this context */ + const struct vm_operations_struct *cxl_mmap_vmops; + struct file *file; + struct list_head list; /* Link contexts in error recovery */ +}; + +struct cxlflash_global { + spinlock_t slock; + struct list_head gluns;/* list of glun_info structs */ + struct page *err_page; /* One page of all 0xF for error notification */ +}; + + +int cxlflash_disk_release(struct scsi_device *, struct dk_cxlflash_release *); +int _cxlflash_disk_release(struct scsi_device *, struct ctx_info *, + struct dk_cxlflash_release *); + +int cxlflash_lun_attach(struct glun_info *, enum lun_mode); +void cxlflash_lun_detach(struct glun_info *); + +struct ctx_info *get_context(struct cxlflash_cfg *, u64, void *, enum ctx_ctrl); + +struct sisl_rht_entry *get_rhte(struct ctx_info *, res_hndl_t, + struct llun_info *); + +struct sisl_rht_entry *rhte_checkout(struct ctx_info *, struct llun_info *); +void rhte_checkin(struct ctx_info *, struct sisl_rht_entry *); + +#endif /* ifndef _CXLFLASH_SUPERPIPE_H */ diff --git a/include/uapi/scsi/Kbuild b/include/uapi/scsi/Kbuild index 75746d5..d791e0a 100644 --- a/include/uapi/scsi/Kbuild +++ b/include/uapi/scsi/Kbuild @@ -3,3 +3,4 @@ header-y += fc/ header-y += scsi_bsg_fc.h header-y += scsi_netlink.h header-y += scsi_netlink_fc.h +header-y += cxlflash_ioctl.h diff --git a/include/uapi/scsi/cxlflash_ioctl.h b/include/uapi/scsi/cxlflash_ioctl.h new file mode 100644 index 0000000..bdaae75 --- /dev/null +++ b/include/uapi/scsi/cxlflash_ioctl.h @@ -0,0 +1,132 @@ +/* + * CXL Flash Device Driver + * + * Written by: Manoj N. Kumar <manoj@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>, IBM Corporation + * + * Copyright (C) 2015 IBM Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _CXLFLASH_IOCTL_H +#define _CXLFLASH_IOCTL_H + +#include <linux/types.h> + +/* + * Structure and flag definitions CXL Flash superpipe ioctls + */ + +struct dk_cxlflash_hdr { + __u16 version; /* Version data */ + __u16 rsvd[3]; /* Reserved for future use */ + __u64 flags; /* Input flags */ + __u64 return_flags; /* Returned flags */ +}; + +/* + * Notes: + * ----- + * The 'context_id' field of all ioctl structures contains the context + * identifier for a context in the lower 32-bits (upper 32-bits are not + * to be used when identifying a context to the AFU). That said, the value + * in its entirety (all 64-bits) is to be treated as an opaque cookie and + * should be presented as such when issuing ioctls. + * + * For DK_CXLFLASH_ATTACH ioctl, user specifies read/write access + * permissions via the O_RDONLY, O_WRONLY, and O_RDWR flags defined in + * the fcntl.h header file. + */ +#define DK_CXLFLASH_ATTACH_REUSE_CONTEXT 0x8000000000000000ULL + +struct dk_cxlflash_attach { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 num_interrupts; /* Requested number of interrupts */ + __u64 context_id; /* Returned context */ + __u64 mmio_size; /* Returned size of MMIO area */ + __u64 block_size; /* Returned block size, in bytes */ + __u64 adap_fd; /* Returned adapter file descriptor */ + __u64 last_lba; /* Returned last LBA on the device */ + __u64 max_xfer; /* Returned max transfer size, blocks */ +}; + +struct dk_cxlflash_detach { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 context_id; /* Context to detach */ +}; + +struct dk_cxlflash_udirect { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 context_id; /* Context to own physical resources */ + __u64 rsrc_handle; /* Returned resource handle */ + __u64 last_lba; /* Returned last LBA on the device */ +}; + +struct dk_cxlflash_release { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 context_id; /* Context owning resources */ + __u64 rsrc_handle; /* Resource handle to release */ +}; + +#define DK_CXLFLASH_VERIFY_SENSE_LEN 18 +#define DK_CXLFLASH_VERIFY_HINT_SENSE 0x8000000000000000ULL + +struct dk_cxlflash_verify { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 context_id; /* Context owning resources to verify */ + __u64 rsrc_handle; /* Resource handle of LUN */ + __u64 hint; /* Reasons for verify */ + __u64 last_lba; /* Returned last LBA of device */ + __u8 sense_data[DK_CXLFLASH_VERIFY_SENSE_LEN]; /* SCSI sense data */ + __u8 pad[6]; /* Pad to next 8-byte boundary */ +}; + +#define DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET 0x8000000000000000ULL + +struct dk_cxlflash_recover_afu { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u64 reason; /* Reason for recovery request */ + __u64 context_id; /* Context to recover / updated ID */ + __u64 mmio_size; /* Returned size of MMIO area */ + __u64 adap_fd; /* Returned adapter file descriptor */ +}; + +#define DK_CXLFLASH_MANAGE_LUN_WWID_LEN 16 +#define DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE 0x8000000000000000ULL +#define DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE 0x4000000000000000ULL +#define DK_CXLFLASH_MANAGE_LUN_ALL_PORTS_ACCESSIBLE 0x2000000000000000ULL + +struct dk_cxlflash_manage_lun { + struct dk_cxlflash_hdr hdr; /* Common fields */ + __u8 wwid[DK_CXLFLASH_MANAGE_LUN_WWID_LEN]; /* Page83 WWID, NAA-6 */ +}; + +union cxlflash_ioctls { + struct dk_cxlflash_attach attach; + struct dk_cxlflash_detach detach; + struct dk_cxlflash_udirect udirect; + struct dk_cxlflash_release release; + struct dk_cxlflash_verify verify; + struct dk_cxlflash_recover_afu recover_afu; + struct dk_cxlflash_manage_lun manage_lun; +}; + +#define MAX_CXLFLASH_IOCTL_SZ (sizeof(union cxlflash_ioctls)) + + +#define CXL_MAGIC 0xCA +#define CXL_IOW(_n, _s) _IOW(CXL_MAGIC, _n, struct _s) + +#define DK_CXLFLASH_ATTACH CXL_IOW(0x80, dk_cxlflash_attach) +#define DK_CXLFLASH_USER_DIRECT CXL_IOW(0x81, dk_cxlflash_udirect) +#define DK_CXLFLASH_RELEASE CXL_IOW(0x84, dk_cxlflash_release) +#define DK_CXLFLASH_DETACH CXL_IOW(0x85, dk_cxlflash_detach) +#define DK_CXLFLASH_VERIFY CXL_IOW(0x86, dk_cxlflash_verify) +#define DK_CXLFLASH_RECOVER_AFU CXL_IOW(0x88, dk_cxlflash_recover_afu) +#define DK_CXLFLASH_MANAGE_LUN CXL_IOW(0x89, dk_cxlflash_manage_lun) + +#endif /* ifndef _CXLFLASH_IOCTL_H */ -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
