Add a bsg endpoint that supports UPIUs. For now, just provide an API to allocate and remove ufs-bsg node. We will use this framework to manage ufs devices by sending UPIU transactions. For the time being, implements an empty bsg_request() - will add some more functionality in coming patches. Nonetheless, we reveal here the protocol we are planning to use: UFS Transport Protocol Transactions. UFS transactions consist of packets called UFS Protocol Information Units (UPIU). There are UPIU’s defined for UFS SCSI commands, responses, data in and data out, task management, utility functions, vendor functions, transaction synchronization and control, and more. By using UPIUs, we get access to the most fine-grained internals of this protocol, and able to communicate with the device in ways, that are sometimes beyond the capacity of the ufs driver. Moreover and as a result, our core structure - ufs_bsg_node has a pretty lean structure: using upiu transactions that contains the outmost detailed info, so we don't really need complex constructs to support it. Signed-off-by: Avri Altman <avri.altman@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Bart Van Assche <Bart.VanAssche@xxxxxxx> --- Documentation/scsi/ufs.txt | 20 +++++++++ drivers/scsi/ufs/Kconfig | 19 ++++++++ drivers/scsi/ufs/Makefile | 3 +- drivers/scsi/ufs/ufs_bsg.c | 93 ++++++++++++++++++++++++++++++++++++++++ drivers/scsi/ufs/ufs_bsg.h | 23 ++++++++++ drivers/scsi/ufs/ufshcd.c | 4 ++ drivers/scsi/ufs/ufshcd.h | 3 ++ include/uapi/scsi/scsi_bsg_ufs.h | 30 ++++++++++++- 8 files changed, 193 insertions(+), 2 deletions(-) create mode 100644 drivers/scsi/ufs/ufs_bsg.c create mode 100644 drivers/scsi/ufs/ufs_bsg.h diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.txt index 41a6164..2616d5f 100644 --- a/Documentation/scsi/ufs.txt +++ b/Documentation/scsi/ufs.txt @@ -128,6 +128,26 @@ The current UFSHCD implementation supports following functionality, In this version of UFSHCD Query requests and power management functionality are not implemented. +4. BSG Support +------------------ + +This transport driver supports exchanging UFS protocol information units +(UPIUs) with an UFS device. Typically, user space will allocate +struct ufs_bsg_request and struct ufs_bsg_reply (see ufs_bsg.h) as +request_upiu and reply_upiu respectively. Filling those UPIUs should +be done in accordance with JEDEC spec UFS2.1 paragraph 10.7. +*Caveat emptor*: The driver makes no further input validations and sends the +UPIU to the device as it is. Open the bsg device in /dev/ufs-bsg and +send SG_IO with the applicable sg_io_v4: + + io_hdr_v4.guard = 'Q'; + io_hdr_v4.protocol = BSG_PROTOCOL_SCSI; + io_hdr_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_TRANSPORT; + io_hdr_v4.response = (__u64)reply_upiu; + io_hdr_v4.max_response_len = reply_len; + io_hdr_v4.request_len = request_len; + io_hdr_v4.request = (__u64)request_upiu; + UFS Specifications can be found at, UFS - http://www.jedec.org/sites/default/files/docs/JESD220.pdf UFSHCI - http://www.jedec.org/sites/default/files/docs/JESD223.pdf diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig index e09fe6a..83ba979 100644 --- a/drivers/scsi/ufs/Kconfig +++ b/drivers/scsi/ufs/Kconfig @@ -109,3 +109,22 @@ config SCSI_UFS_HISI Select this if you have UFS controller on Hisilicon chipset. If unsure, say N. + +config SCSI_UFS_BSG + bool "Universal Flash Storage BSG device node" + depends on SCSI_UFSHCD + select BLK_DEV_BSGLIB + help + Universal Flash Storage (UFS) is SCSI transport specification for + accessing flash storage on digital cameras, mobile phones and + consumer electronic devices. + An UFS controller communicates with an UFS device by exchanging + UFS Protocol Information Units (UPIUs). + UPIUs can not only be used as a transport layer for the SCSI protocol + but are also used by the UFS native command set. + This transport driver supports exchanging UFS protocol information units + with an UFS device. See also the ufshcd driver, which is a SCSI driver + that supports UFS devices. + + Select this if you need a bsg device node for your UFS controller. + If unsure, say N. diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile index 2c50f03..aca4813 100644 --- a/drivers/scsi/ufs/Makefile +++ b/drivers/scsi/ufs/Makefile @@ -4,7 +4,8 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210. obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o -ufshcd-core-objs := ufshcd.o ufs-sysfs.o +ufshcd-core-y += ufshcd.o ufs-sysfs.o +ufshcd-core-$(CONFIG_SCSI_UFS_BSG) += ufs_bsg.o obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o obj-$(CONFIG_SCSI_UFS_HISI) += ufs-hisi.o diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c new file mode 100644 index 0000000..1036c52 --- /dev/null +++ b/drivers/scsi/ufs/ufs_bsg.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * bsg endpoint that supports UPIUs + * + * Copyright (C) 2018 Western Digital Corporation + */ +#include "ufs_bsg.h" + + +static int ufs_bsg_request(struct bsg_job *job) +{ + struct ufs_bsg_request *bsg_request = job->request; + struct ufs_bsg_reply *bsg_reply = job->reply; + int ret = -ENOTSUPP; + + bsg_reply->reply_payload_rcv_len = 0; + + /* Do Nothing for now */ + dev_err(job->dev, "unsupported message_code 0x%x\n", + bsg_request->msgcode); + + bsg_reply->result = ret; + job->reply_len = sizeof(struct ufs_bsg_reply) + + bsg_reply->reply_payload_rcv_len; + + bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len); + + return ret; +} + +/** + * ufs_bsg_remove - detach and remove the added ufs-bsg node + * + * Should be called when unloading the driver. + */ +void ufs_bsg_remove(struct ufs_hba *hba) +{ + struct device *bsg_dev = &hba->bsg_dev; + + if (!hba->bsg_queue) + return; + + bsg_unregister_queue(hba->bsg_queue); + + device_del(bsg_dev); + put_device(bsg_dev); +} + +static inline void ufs_bsg_node_release(struct device *dev) +{ + put_device(dev->parent); +} + +/** + * ufs_bsg_probe - Add ufs bsg device node + * @hba: per adapter object + * + * Called during initial loading of the driver, and before scsi_scan_host. + */ +int ufs_bsg_probe(struct ufs_hba *hba) +{ + struct device *bsg_dev = &hba->bsg_dev; + struct Scsi_Host *shost = hba->host; + struct device *parent = &shost->shost_gendev; + struct request_queue *q; + int ret; + + device_initialize(bsg_dev); + + bsg_dev->parent = get_device(parent); + bsg_dev->release = ufs_bsg_node_release; + + dev_set_name(bsg_dev, "ufs-bsg"); + + ret = device_add(bsg_dev); + if (ret) + goto out; + + q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), ufs_bsg_request, 0); + if (IS_ERR(q)) { + ret = PTR_ERR(q); + goto out; + } + + hba->bsg_queue = q; + + return 0; + +out: + dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no); + put_device(bsg_dev); + return ret; +} diff --git a/drivers/scsi/ufs/ufs_bsg.h b/drivers/scsi/ufs/ufs_bsg.h new file mode 100644 index 0000000..d099187 --- /dev/null +++ b/drivers/scsi/ufs/ufs_bsg.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Western Digital Corporation + */ +#ifndef UFS_BSG_H +#define UFS_BSG_H + +#include <linux/bsg-lib.h> +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> + +#include "ufshcd.h" +#include "ufs.h" + +#ifdef CONFIG_SCSI_UFS_BSG +void ufs_bsg_remove(struct ufs_hba *hba); +int ufs_bsg_probe(struct ufs_hba *hba); +#else +static inline void ufs_bsg_remove(struct ufs_hba *hba) {} +static inline int ufs_bsg_probe(struct ufs_hba *hba) {return 0; } +#endif + +#endif /* UFS_BSG_H */ diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index fdbf07a..7f376fb 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -46,6 +46,7 @@ #include "ufs_quirks.h" #include "unipro.h" #include "ufs-sysfs.h" +#include "ufs_bsg.h" #define CREATE_TRACE_POINTS #include <trace/events/ufs.h> @@ -6633,6 +6634,8 @@ static int ufshcd_probe_hba(struct ufs_hba *hba) hba->clk_scaling.is_allowed = true; } + ufs_bsg_probe(hba); + scsi_scan_host(hba->host); pm_runtime_put_sync(hba->dev); } @@ -7854,6 +7857,7 @@ int ufshcd_shutdown(struct ufs_hba *hba) */ void ufshcd_remove(struct ufs_hba *hba) { + ufs_bsg_remove(hba); ufs_sysfs_remove_nodes(hba->dev); scsi_remove_host(hba->host); /* disable interrupts */ diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 33fdd3f..54e6fe8 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -702,6 +702,9 @@ struct ufs_hba { struct rw_semaphore clk_scaling_lock; struct ufs_desc_size desc_size; atomic_t scsi_block_reqs_cnt; + + struct device bsg_dev; + struct request_queue *bsg_queue; }; /* Returns true if clocks can be gated. Otherwise false */ diff --git a/include/uapi/scsi/scsi_bsg_ufs.h b/include/uapi/scsi/scsi_bsg_ufs.h index 4108ce3..3b83375 100644 --- a/include/uapi/scsi/scsi_bsg_ufs.h +++ b/include/uapi/scsi/scsi_bsg_ufs.h @@ -1,8 +1,9 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* - * TBD - UFS Transport SGIO v4 BSG Message Support + * UFS Transport SGIO v4 BSG Message Support * * Copyright (C) 2011-2013 Samsung India Software Operations + * Copyright (C) 2018 Western Digital Corporation */ #ifndef SCSI_BSG_UFS_H #define SCSI_BSG_UFS_H @@ -69,6 +70,33 @@ struct utp_upiu_req { union { struct utp_upiu_cmd sc; struct utp_upiu_query qr; + struct utp_upiu_query tr; + /* use utp_upiu_query to host the 4 dwords of uic command */ + struct utp_upiu_query uc; }; }; + +/* request (CDB) structure of the sg_io_v4 */ +struct ufs_bsg_request { + uint32_t msgcode; + struct utp_upiu_req upiu_req; +}; + +/* response (request sense data) structure of the sg_io_v4 */ +struct ufs_bsg_reply { + /* + * The completion result. Result exists in two forms: + * if negative, it is an -Exxx system errno value. There will + * be no further reply information supplied. + * else, it's the 4-byte scsi error result, with driver, host, + * msg and status fields. The per-msgcode reply structure + * will contain valid data. + */ + uint32_t result; + + /* If there was reply_payload, how much was received? */ + uint32_t reply_payload_rcv_len; + + struct utp_upiu_req upiu_rsp; +}; #endif /* UFS_BSG_H */ -- 1.9.1
