[PATCH/RESEND V4 10/17] scsi: ufs: introduce well known logical unit in ufs

Dolev Raviv
2014-09-23T07:32:27Z

From: Subhash Jadavani <subhashj@codeaurora.org>

UFS device may have standard LUs and LUN id could be from 0x00 to 0x7F.
UFS device specification use "Peripheral Device Addressing Format"
(SCSI SAM-5) for standard LUs.

UFS device may also have the Well Known LUs (also referred as W-LU) which
again could be from 0x00 to 0x7F. For W-LUs, UFS device specification only
allows the "Extended Addressing Format" (SCSI SAM-5) which means the W-LUNs
would start from 0xC100 onwards.

This means max. LUN number reported from UFS device could be 0xC17F hence
this patch advertise the "max_lun" as 0xC17F which will allow SCSI mid
layer to detect the W-LUs as well.

But once the W-LUs are detected, UFSHCD driver may get the commands with
SCSI LUN id upto 0xC17F but UPIU LUN id field is only 8-bit wide so it
requires the mapping of SCSI LUN id to UPIU LUN id. This patch also add
support for this mapping.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 4ca99ed..37d64c1 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -49,9 +49,28 @@
#define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
(byte1 << 8) | (byte0))
-
+/*
+ * UFS device may have standard LUs and LUN id could be from 0x00 to
+ * 0x7F. Standard LUs use "Peripheral Device Addressing Format".
+ * UFS device may also have the Well Known LUs (also referred as W-LU)
+ * which again could be from 0x00 to 0x7F. For W-LUs, device only use
+ * the "Extended Addressing Format" which means the W-LUNs would be
+ * from 0xc100 (SCSI_W_LUN_BASE) onwards.
+ * This means max. LUN number reported from UFS device could be 0xC17F.
+ */
+#define UFS_UPIU_MAX_UNIT_NUM_ID 0x7F
+#define UFS_MAX_LUNS (SCSI_W_LUN_BASE + UFS_UPIU_MAX_UNIT_NUM_ID)
+#define UFS_UPIU_WLUN_ID (1 << 7)
#define UFS_UPIU_MAX_GENERAL_LUN 8

+/* Well known logical unit id in LUN field of UPIU */
+enum {
+ UFS_UPIU_REPORT_LUNS_WLUN = 0x81,
+ UFS_UPIU_UFS_DEVICE_WLUN = 0xD0,
+ UFS_UPIU_BOOT_WLUN = 0xB0,
+ UFS_UPIU_RPMB_WLUN = 0xC4,
+};
+
/*
* UFS Protocol Information Unit related definitions
*/
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1c5422b..de41630 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -100,7 +100,6 @@ static u32 ufs_query_desc_max_size[] = {
enum {
UFSHCD_MAX_CHANNEL = 0,
UFSHCD_MAX_ID = 1,
- UFSHCD_MAX_LUNS = 8,
UFSHCD_CMD_PER_LUN = 32,
UFSHCD_CAN_QUEUE = 32,
};
@@ -901,6 +900,21 @@ static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
return ret;
}

+/*
+ * ufshcd_scsi_to_upiu_lun - maps scsi LUN to UPIU LUN
+ * @scsi_lun: scsi LUN id
+ *
+ * Returns UPIU LUN id
+ */
+static inline u8 ufshcd_scsi_to_upiu_lun(unsigned int scsi_lun)
+{
+ if (scsi_is_wlun(scsi_lun))
+ return (scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID)
+ | UFS_UPIU_WLUN_ID;
+ else
+ return scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID;
+}
+
/**
* ufshcd_upiu_wlun_to_scsi_wlun - maps UPIU W-LUN id to SCSI W-LUN ID
* @scsi_lun: UPIU W-LUN id
@@ -970,7 +984,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
lrbp->sense_buffer = cmd->sense_buffer;
lrbp->task_tag = tag;
- lrbp->lun = cmd->device->lun;
+ lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
lrbp->intr_cmd = false;
lrbp->command_type = UTP_CMD_TYPE_SCSI;

@@ -1524,7 +1538,7 @@ static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
* Unit descriptors are only available for general purpose LUs (LUN id
* from 0 to 7) and RPMB Well known LU.
*/
- if (lun >= UFS_UPIU_MAX_GENERAL_LUN)
+ if (lun != UFS_UPIU_RPMB_WLUN && (lun >= UFS_UPIU_MAX_GENERAL_LUN))
return -EOPNOTSUPP;

return ufshcd_read_desc_param(hba, QUERY_DESC_IDN_UNIT, lun,
@@ -2155,6 +2169,44 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
}

/**
+ * ufshcd_set_queue_depth - set lun queue depth
+ * @sdev: pointer to SCSI device
+ *
+ * Read bLUQueueDepth value and activate scsi tagged command
+ * queueing. For WLUN, queue depth is set to 1. For best-effort
+ * cases (bLUQueueDepth = 0) the queue depth is set to a maximum
+ * value that host can queue.
+ */
+static void ufshcd_set_queue_depth(struct scsi_device *sdev)
+{
+ int ret = 0;
+ u8 lun_qdepth;
+ struct ufs_hba *hba;
+
+ hba = shost_priv(sdev->host);
+
+ lun_qdepth = hba->nutrs;
+ ret = ufshcd_read_unit_desc_param(hba,
+ ufshcd_scsi_to_upiu_lun(sdev->lun),
+ UNIT_DESC_PARAM_LU_Q_DEPTH,
+ &lun_qdepth,
+ sizeof(lun_qdepth));
+
+ /* Some WLUN doesn't support unit descriptor */
+ if (ret == -EOPNOTSUPP)
+ lun_qdepth = 1;
+ else if (!lun_qdepth)
+ /* eventually, we can figure out the real queue depth */
+ lun_qdepth = hba->nutrs;
+ else
+ lun_qdepth = min_t(int, lun_qdepth, hba->nutrs);
+
+ dev_dbg(hba->dev, "%s: activate tcq with queue depth %d\n",
+ __func__, lun_qdepth);
+ scsi_activate_tcq(sdev, lun_qdepth);
+}
+
+/**
* ufshcd_slave_alloc - handle initial SCSI device configurations
* @sdev: pointer to SCSI device
*
@@ -2163,8 +2215,6 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
static int ufshcd_slave_alloc(struct scsi_device *sdev)
{
struct ufs_hba *hba;
- u8 lun_qdepth;
- int ret;

hba = shost_priv(sdev->host);
sdev->tagged_supported = 1;
@@ -2179,20 +2229,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)
/* REPORT SUPPORTED OPERATION CODES is not supported */
sdev->no_report_opcodes = 1;

- ret = ufshcd_read_unit_desc_param(hba,
- sdev->lun,
- UNIT_DESC_PARAM_LU_Q_DEPTH,
- &lun_qdepth,
- sizeof(lun_qdepth));
- if (!ret || !lun_qdepth)
- /* eventually, we can figure out the real queue depth */
- lun_qdepth = hba->nutrs;
- else
- lun_qdepth = min_t(int, lun_qdepth, hba->nutrs);

- dev_dbg(hba->dev, "%s: activate tcq with queue depth %d\n",
- __func__, lun_qdepth);
- scsi_activate_tcq(sdev, lun_qdepth);
+ ufshcd_set_queue_depth(sdev);

return 0;
}
@@ -2255,6 +2293,9 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev)

hba = shost_priv(sdev->host);
scsi_deactivate_tcq(sdev, hba->nutrs);
+ /* Drop the reference as it won't be needed anymore */
+ if (ufshcd_scsi_to_upiu_lun(sdev->lun) == UFS_UPIU_UFS_DEVICE_WLUN)
+ hba->sdev_ufs_device = NULL;
}

/**
@@ -2972,7 +3013,10 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
lun_id, task_tag);
task_req_upiup->header.dword_1 =
UPIU_HEADER_DWORD(0, tm_function, 0, 0);
-
+ /*
+ * The host shall provide the same value for LUN field in the basic
+ * header and for Input Parameter.
+ */
task_req_upiup->input_param1 = cpu_to_be32(lun_id);
task_req_upiup->input_param2 = cpu_to_be32(task_id);

@@ -4038,7 +4082,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
host->can_queue = hba->nutrs;
host->cmd_per_lun = hba->nutrs;
host->max_id = UFSHCD_MAX_ID;
- host->max_lun = UFSHCD_MAX_LUNS;
+ host->max_lun = UFS_MAX_LUNS;
host->max_channel = UFSHCD_MAX_CHANNEL;
host->unique_id = host->host_no;
host->max_cmd_len = MAX_CDB_SIZE;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8365ad4..9b5f77f 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -124,7 +124,7 @@ struct ufshcd_lrb {

int command_type;
int task_tag;
- unsigned int lun;
+ u8 lun; /* UPIU LUN id field is only 8-bit wide */
bool intr_cmd;
};

@@ -266,6 +266,11 @@ struct ufs_hba {

struct Scsi_Host *host;
struct device *dev;
+ /*
+ * This field is to keep a reference to "scsi_device" corresponding to
+ * "UFS device" W-LU.
+ */
+ struct scsi_device *sdev_ufs_device;

struct ufshcd_lrb *lrb;
unsigned long lrb_in_use;