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>
---
drivers/scsi/ufs/Kconfig | 19 ++++++
drivers/scsi/ufs/Makefile | 3 +
drivers/scsi/ufs/ufs_bsg.c | 156 +++++++++++++++++++++++++++++++++++++++++++++
drivers/scsi/ufs/ufs_bsg.h | 64 +++++++++++++++++++
drivers/scsi/ufs/ufshcd.c | 4 ++
drivers/scsi/ufs/ufshcd.h | 2 +
6 files changed, 248 insertions(+)
create mode 100644 drivers/scsi/ufs/ufs_bsg.c
create mode 100644 drivers/scsi/ufs/ufs_bsg.h
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..80041ab 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -5,6 +5,9 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
ufshcd-core-objs := ufshcd.o ufs-sysfs.o
+ifeq ($(CONFIG_SCSI_UFS_BSG),y)
+ufshcd-core-objs += ufs_bsg.o
+endif
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..d33ada9
--- /dev/null
+++ b/drivers/scsi/ufs/ufs_bsg.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * bsg endpoint that supports UPIUs
+ *
+ * Copyright (C) 2018 Western Digital Corporation
+ */
+#include "ufs_bsg.h"
+
+struct ufs_bsg_node {
+ struct device dev;
+ struct request_queue *q;
+};
+
+
+static inline struct ufs_bsg_node *dev_to_ufs_node(struct device *d)
+{
+ return container_of(d, struct ufs_bsg_node, dev);
+}
+
+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;
+ if (ret)
+ job->reply_len = sizeof(uint32_t);
+ else
+ job->reply_len = sizeof(struct ufs_bsg_reply) +
+ bsg_reply->reply_payload_rcv_len;
+
+ bsg_job_done(job, bsg_reply->result, bsg_reply->reply_payload_rcv_len);
+
+ return ret;
+}
+
+static void ufs_bsg_node_delete(struct ufs_bsg_node *node)
+{
+ struct device *dev = &node->dev;
+
+ if (node->q)
+ bsg_unregister_queue(node->q);
+
+ device_del(dev);
+
+ put_device(dev);
+}
+
+/**
+ * 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)
+{
+ if (!hba->bsg_node)
+ return;
+
+ ufs_bsg_node_delete(hba->bsg_node);
+}
+
+static void ufs_bsg_node_release(struct device *dev)
+{
+ struct ufs_bsg_node *node = dev_to_ufs_node(dev);
+
+ put_device(dev->parent);
+ kfree(node);
+}
+
+static struct ufs_bsg_node *ufs_bsg_node_alloc(struct Scsi_Host *shost)
+{
+ struct ufs_bsg_node *node;
+ struct device *parent = &shost->shost_gendev;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return NULL;
+
+ device_initialize(&node->dev);
+
+ node->dev.parent = get_device(parent);
+ node->dev.release = ufs_bsg_node_release;
+
+ dev_set_name(&node->dev, "ufs-bsg-%d:0", shost->host_no);
+
+ return node;
+}
+
+static int ufs_bsg_initialize(struct Scsi_Host *shost,
+ struct ufs_bsg_node *node)
+{
+ struct request_queue *q;
+
+ q = bsg_setup_queue(&node->dev, dev_name(&node->dev),
+ ufs_bsg_request, 0);
+ if (IS_ERR(q))
+ return PTR_ERR(q);
+ node->q = q;
+
+ return 0;
+}
+
+static int ufs_bsg_node_add(struct ufs_bsg_node *node)
+{
+ struct device *dev = &node->dev;
+ struct Scsi_Host *shost = dev_to_shost(dev->parent);
+ int error;
+
+ error = device_add(dev);
+ if (error)
+ return error;
+
+ if (ufs_bsg_initialize(shost, node))
+ dev_err(dev, "fail to initialize a bsg dev %d\n",
+ shost->host_no);
+
+ return 0;
+}
+
+/**
+ * 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 ufs_bsg_node *node;
+ int ret;
+
+ node = ufs_bsg_node_alloc(hba->host);
+ if (!node) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = ufs_bsg_node_add(node);
+ if (ret)
+ goto out_free_node;
+
+ hba->bsg_node = node;
+
+ return 0;
+
+out_free_node:
+ put_device(&node->dev);
+out:
+ return ret;
+}
diff --git a/drivers/scsi/ufs/ufs_bsg.h b/drivers/scsi/ufs/ufs_bsg.h
new file mode 100644
index 0000000..36d3a12
--- /dev/null
+++ b/drivers/scsi/ufs/ufs_bsg.h
@@ -0,0 +1,64 @@
+/* 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"
+
+#define UPIU_TRANSACTION_UIC_CMD 0x1F
+
+enum {
+ REQ_UPIU_SIZE_DWORDS = 8,
+ RSP_UPIU_SIZE_DWORDS = 8,
+};
+
+struct ufs_bsg_request {
+ uint32_t msgcode;
+ struct utp_upiu_header header;
+ union {
+ 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;
+ } tsf;
+};
+
+
+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_header header;
+ union {
+ struct utp_upiu_query qr;
+ struct utp_upiu_query tr;
+ struct utp_upiu_query uc;
+ } tsf;
+};
+
+#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 d021c3a..e53e145 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>
@@ -6621,6 +6622,8 @@ 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);
}
@@ -7844,6 +7847,7 @@ 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..46ea7c3 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -702,6 +702,8 @@ struct ufs_hba {
struct rw_semaphore clk_scaling_lock;
struct ufs_desc_size desc_size;
atomic_t scsi_block_reqs_cnt;
+
+ struct ufs_bsg_node *bsg_node;
};
/* Returns true if clocks can be gated. Otherwise false */
--
1.9.1
