[PATCH v2 2/5] [SCSI] ufshcd: UFS UTP Transfer requests handling

From: Santosh Y
Date: Fri Feb 24 2012 - 02:20:17 EST

From: Santosh Yaraganavi <santoshsy@xxxxxxxxx>

This patch adds support for Transfer request handling.

ufshcd includes following implementations:
- SCSI queuecommand
- Compose UPIU(UFS Protocol information unit)
- Issue commands to UFS host controller
- Handle completed commands

Signed-off-by: Santosh Yaraganavi <santoshsy@xxxxxxxxx>
Signed-off-by: Vinayak Holikatti <vinholikatti@xxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxxxx>
Reviewed-by: Vishak G <vishak.g@xxxxxxxxxxx>
Reviewed-by: Girish K S <girish.shivananjappa@xxxxxxxxxx>
---
v1 -> v2:
- Use bitops.h defined functions to perform bit operations.
Ex: set_bit(), __set_bit, clear_bit...
- ufshcd_map_sg(): remove BUG_ON on scsi_dma_map() failure
and return error value.
- ufshcd_compose_upiu(): add missing break in switch case,
remove unused parameter "hba".
- ufshcd_slave_alloc(): set sdev->use_10_for_ms = 1, since UFS
does not support MODE_SENSE_6.
- ufshcd_scsi_cmd_status(): add missing break in switch case.
Add ufshcd_adjust_lun_qdepth to adjust LUN queue depth
if SAM_STAT_TASK_SET_FULL is received from the device.
- ufshcd_transfer_rsp_status(): combine cases with same error code.

drivers/scsi/ufs/ufshcd.c | 500 +++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 500 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index abf617e..e4335f5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -63,6 +63,7 @@
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
+#include <scsi/scsi_tcq.h>
#include <scsi/scsi_dbg.h>

#include "ufs.h"
@@ -75,6 +76,8 @@ enum {
UFSHCD_MAX_CHANNEL = 0,
UFSHCD_MAX_ID = 1,
UFSHCD_MAX_LUNS = 8,
+ UFSHCD_CMD_PER_LUN = 32,
+ UFSHCD_CAN_QUEUE = 32,
};

/* UFSHCD states */
@@ -128,6 +131,7 @@ struct uic_command {
* @host: Scsi_Host instance of the driver
* @pdev: PCI device handle
* @lrb: local reference block
+ * @outstanding_reqs: Bits representing outstanding transfer requests
* @capabilities: UFS Controller Capabilities
* @nutrs: Transfer Request Queue depth supported by controller
* @nutmrs: Task Management Queue depth supported by controller
@@ -154,6 +158,8 @@ struct ufs_hba {

struct ufshcd_lrb *lrb;

+ unsigned long outstanding_reqs;
+
u32 capabilities;
int nutrs;
int nutmrs;
@@ -174,12 +180,28 @@ struct ufs_hba {
* @ucd_cmd_ptr: UCD address of the command
* @ucd_rsp_ptr: Response UPIU address for this command
* @ucd_prdt_ptr: PRDT address of the command
+ * @cmd: pointer to SCSI command
+ * @sense_buffer: pointer sense buffer address of the SCSI command
+ * @sense_bufflen: Length of the sense buffer
+ * @scsi_status: SCSI status of the command
+ * @command_type: SCSI, UFS, Query.
+ * @task_tag: Task tag of the command
+ * @lun: LUN of the command
*/
struct ufshcd_lrb {
struct utp_transfer_req_desc *utr_descriptor_ptr;
struct utp_upiu_cmd *ucd_cmd_ptr;
struct utp_upiu_rsp *ucd_rsp_ptr;
struct ufshcd_sg_entry *ucd_prdt_ptr;
+
+ struct scsi_cmnd *cmd;
+ u8 *sense_buffer;
+ unsigned int sense_bufflen;
+ int scsi_status;
+
+ int command_type;
+ int task_tag;
+ unsigned int lun;
};

/**
@@ -206,6 +228,18 @@ static inline int ufshcd_is_device_present(u32 reg_hcs)
}

/**
+ * ufshcd_get_tr_ocs - Get the UTRD Overall Command Status
+ * @lrb: pointer to local command reference block
+ *
+ * This function is used to get the OCS field from UTRD
+ * Returns the OCS field in the UTRD
+ */
+static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
+{
+ return lrbp->utr_descriptor_ptr->header.dword_2 & MASK_OCS;
+}
+
+/**
* ufshcd_get_lists_status - Check UCRDY, UTRLRDY and UTMRLRDY
* @reg: Register value of host controller status
*
@@ -273,6 +307,36 @@ static inline void ufshcd_free_hba_memory(struct ufs_hba *hba)
}

/**
+ * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * This function checks the response UPIU for valid transaction type in
+ * response field
+ * Returns 0 on success, non-zero on failure
+ */
+static inline int
+ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+ return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
+ UPIU_TRANSACTION_RESPONSE) ? 0 :
+ (DID_ERROR << 16 |
+ COMMAND_COMPLETE << 8);
+}
+
+/**
+ * ufshcd_get_rsp_upiu_result - Get the result from response UPIU
+ * @ucd_rsp_ptr: pointer to response UPIU
+ *
+ * This function gets the response status and scsi_status from response UPIU
+ * Returns the response result code.
+ */
+static inline int
+ufshcd_get_rsp_upiu_result(struct utp_upiu_rsp *ucd_rsp_ptr)
+{
+ return be32_to_cpu(ucd_rsp_ptr->header.dword_1) & MASK_RSP_UPIU_RESULT;
+}
+
+/**
* ufshcd_config_int_aggr - Configure interrupt aggregation values
* currently there is no use case where we want to configure
* interrupt aggregation dynamically. So to configure interrupt
@@ -348,6 +412,34 @@ static inline int ufshcd_is_hba_active(struct ufs_hba *hba)
}

/**
+ * ufshcd_send_command - Send SCSI or device management commands
+ * @hba: per adapter instance
+ * @task_tag: Task tag of the command
+ */
+static inline
+void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
+{
+ __set_bit(task_tag, &hba->outstanding_reqs);
+ writel((1 << task_tag),
+ (hba->mmio_base + REG_UTP_TRANSFER_REQ_DOOR_BELL));
+}
+
+/**
+ * ufshcd_copy_sense_data - Copy sense data in case of check condition
+ * @lrb - pointer to local reference block
+ */
+static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
+{
+ int len;
+ if (lrbp->sense_buffer) {
+ len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
+ memcpy(lrbp->sense_buffer,
+ lrbp->ucd_rsp_ptr->sense_data,
+ min_t(int, len, SCSI_SENSE_BUFFERSIZE));
+ }
+}
+
+/**
* ufshcd_hba_capabilities - Read controller capabilities
* @hba: per adapter instance
*/
@@ -384,6 +476,46 @@ ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
}

/**
+ * ufshcd_map_sg - Map scatter-gather list to prdt
+ * @lrbp - pointer to local reference block
+ *
+ * Returns 0 in case of success, non-zero value in case of failure
+ */
+static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
+{
+ struct ufshcd_sg_entry *prd_table;
+ struct scatterlist *sg;
+ struct scsi_cmnd *cmd;
+ int sg_segments;
+ int i;
+
+ cmd = lrbp->cmd;
+ sg_segments = scsi_dma_map(cmd);
+ if (sg_segments < 0)
+ return sg_segments;
+
+ if (sg_segments) {
+ lrbp->utr_descriptor_ptr->prd_table_length =
+ cpu_to_le16((u16) (sg_segments));
+
+ prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
+
+ scsi_for_each_sg(cmd, sg, sg_segments, i) {
+ prd_table[i].size =
+ cpu_to_le32(((u32) sg_dma_len(sg))-1);
+ prd_table[i].base_addr =
+ cpu_to_le32(sg->dma_address);
+ prd_table[i].upper_addr =
+ cpu_to_le32((sg->dma_address >> 32));
+ }
+ } else {
+ lrbp->utr_descriptor_ptr->prd_table_length = 0;
+ }
+
+ return 0;
+}
+
+/**
* ufshcd_int_config - enable/disable interrupts
* @hba: per adapter instance
* @option: interrupt option
@@ -407,6 +539,127 @@ static void ufshcd_int_config(struct ufs_hba *hba, u32 option)
}

/**
+ * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @lrb - pointer to local reference block
+ */
+static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
+{
+ struct utp_transfer_req_desc *req_desc;
+ struct utp_upiu_cmd *ucd_cmd_ptr;
+ u32 data_direction;
+ u32 upiu_flags;
+
+ ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
+ req_desc = lrbp->utr_descriptor_ptr;
+
+ switch (lrbp->command_type) {
+ case UTP_CMD_TYPE_SCSI:
+ if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
+ data_direction = UTP_DEVICE_TO_HOST;
+ upiu_flags = UPIU_CMD_FLAGS_READ;
+ } else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
+ data_direction = UTP_HOST_TO_DEVICE;
+ upiu_flags = UPIU_CMD_FLAGS_WRITE;
+ } else {
+ data_direction = UTP_NO_DATA_TRANSFER;
+ upiu_flags = UPIU_CMD_FLAGS_NONE;
+ }
+
+ /* Transfer request descriptor header fields */
+ req_desc->header.dword_0 =
+ cpu_to_le32(data_direction | UTP_SCSI_COMMAND);
+
+ /*
+ * assigning invalid value for command status. Controller
+ * updates OCS on command completion, with the command
+ * status
+ */
+ req_desc->header.dword_2 =
+ cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+
+ /* command descriptor fields */
+ ucd_cmd_ptr->header.dword_0 =
+ cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
+ upiu_flags,
+ lrbp->lun,
+ lrbp->task_tag));
+ ucd_cmd_ptr->header.dword_1 =
+ cpu_to_be32(
+ UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
+ 0,
+ 0,
+ 0));
+
+ /* Total EHS length and Data segment length will be zero */
+ ucd_cmd_ptr->header.dword_2 = 0;
+
+ ucd_cmd_ptr->exp_data_transfer_len =
+ cpu_to_be32(lrbp->cmd->transfersize);
+
+ memcpy(ucd_cmd_ptr->cdb,
+ lrbp->cmd->cmnd,
+ (min_t(unsigned short,
+ lrbp->cmd->cmd_len,
+ MAX_CDB_SIZE)));
+ break;
+ case UTP_CMD_TYPE_DEV_MANAGE:
+ /* For query function implementation */
+ break;
+ case UTP_CMD_TYPE_UFS:
+ /* For UFS native command implementation */
+ break;
+ } /* end of switch, command_type */
+}
+
+/**
+ * ufshcd_queuecommand - main entry point for SCSI requests
+ * @cmd: command from SCSI Midlayer
+ * @done: call back function
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
+{
+ struct ufshcd_lrb *lrbp;
+ struct ufs_hba *hba;
+ unsigned long flags;
+ int tag;
+ int err = 0;
+
+ hba = (struct ufs_hba *) &host->hostdata[0];
+
+ tag = cmd->request->tag;
+
+ if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) {
+ err = SCSI_MLQUEUE_HOST_BUSY;
+ goto out;
+ }
+
+ lrbp = &hba->lrb[tag];
+
+ lrbp->cmd = cmd;
+ lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
+ lrbp->sense_buffer = cmd->sense_buffer;
+ lrbp->task_tag = tag;
+ lrbp->lun = cmd->device->lun;
+
+ lrbp->command_type = UTP_CMD_TYPE_SCSI;
+
+ /* form UPIU before issuing the command */
+ ufshcd_compose_upiu(lrbp);
+ err = ufshcd_map_sg(lrbp);
+ if (err)
+ goto out;
+
+ /* issue command to the controller */
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ ufshcd_send_command(hba, tag);
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+out:
+ return err;
+}
+
+/**
* ufshcd_memory_alloc - allocate memory for host memory space data structures
* @hba: per adapter instance
*
@@ -644,6 +897,7 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba)
ufshcd_config_int_aggr(hba, INT_AGGR_CONFIG);

hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
+ scsi_scan_host(hba->host);
out:
return err;
}
@@ -743,6 +997,235 @@ static int ufshcd_initialize_hba(struct ufs_hba *hba)
}

/**
+ * ufshcd_slave_alloc - handle initial SCSI device configurations
+ * @sdev: pointer to SCSI device
+ *
+ * Returns success
+ */
+static int ufshcd_slave_alloc(struct scsi_device *sdev)
+{
+ struct ufs_hba *hba;
+
+ hba = (struct ufs_hba *)sdev->host->hostdata;
+ sdev->tagged_supported = 1;
+
+ /* Mode sense(6) is not supported by UFS, so use Mode sense(10) */
+ sdev->use_10_for_ms = 1;
+ scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
+
+ /*
+ * Inform SCSI Midlayer that the LUN queue depth is same as the
+ * controller queue depth. If a LUN queue depth is less than the
+ * controller queue depth and if the LUN reports
+ * SAM_STAT_TASK_SET_FULL, the LUN queue depth will be adjusted
+ * with scsi_adjust_queue_depth.
+ */
+ scsi_activate_tcq(sdev, hba->nutrs);
+ return 0;
+}
+
+/**
+ * ufshcd_slave_destroy - remove SCSI device configurations
+ * @sdev: pointer to SCSI device
+ */
+static void ufshcd_slave_destroy(struct scsi_device *sdev)
+{
+ struct ufs_hba *hba;
+
+ hba = (struct ufs_hba *)sdev->host->hostdata;
+ scsi_deactivate_tcq(sdev, hba->nutrs);
+}
+
+/**
+ * ufshcd_adjust_lun_qdepth - Update LUN queue depth if device responds with
+ * SAM_STAT_TASK_SET_FULL SCSI command status.
+ * @cmd: pointer to SCSI command
+ */
+static void ufshcd_adjust_lun_qdepth(struct scsi_cmnd *cmd)
+{
+ struct ufs_hba *hba;
+ int i;
+ int lun_qdepth = 0;
+
+ hba = (struct ufs_hba *) cmd->device->host->hostdata;
+
+ /*
+ * LUN queue depth can be obtained by counting outstanding commands
+ * on the LUN.
+ */
+ for (i = 0; i < hba->nutrs; i++) {
+ if (test_bit(i, &hba->outstanding_reqs)) {
+
+ /*
+ * Check if the outstanding command belongs
+ * to the LUN which reported SAM_STAT_TASK_SET_FULL.
+ */
+ if (cmd->device->lun == hba->lrb[i].lun)
+ lun_qdepth++;
+ }
+ }
+
+ /*
+ * LUN queue depth will be total outstanding commands, except the
+ * command for which the LUN reported SAM_STAT_TASK_SET_FULL.
+ */
+ scsi_adjust_queue_depth(cmd->device, MSG_SIMPLE_TAG, lun_qdepth - 1);
+}
+
+/**
+ * ufshcd_scsi_cmd_status - Update SCSI command result based on SCSI status
+ * @lrb: pointer to local reference block of completed command
+ * @scsi_status: SCSI command status
+ *
+ * Returns value base on SCSI command status
+ */
+static inline int
+ufshcd_scsi_cmd_status(struct ufshcd_lrb *lrbp, int scsi_status)
+{
+ int result = 0;
+
+ switch (scsi_status) {
+ case SAM_STAT_GOOD:
+ result |= DID_OK << 16 |
+ COMMAND_COMPLETE << 8 |
+ SAM_STAT_GOOD;
+ break;
+ case SAM_STAT_CHECK_CONDITION:
+ result |= DRIVER_SENSE << 24 |
+ DRIVER_OK << 16 |
+ COMMAND_COMPLETE << 8 |
+ SAM_STAT_CHECK_CONDITION;
+ ufshcd_copy_sense_data(lrbp);
+ break;
+ case SAM_STAT_BUSY:
+ result |= DID_BUS_BUSY << 16 |
+ SAM_STAT_BUSY;
+ break;
+ case SAM_STAT_TASK_SET_FULL:
+
+ /*
+ * If a LUN reports SAM_STAT_TASK_SET_FULL, then the LUN queue
+ * depth needs to be adjusted to the exact number of
+ * outstanding commands the LUN can handle at any given time.
+ */
+ ufshcd_adjust_lun_qdepth(lrbp->cmd);
+ result |= DID_SOFT_ERROR << 16 |
+ SAM_STAT_TASK_SET_FULL;
+ break;
+ case SAM_STAT_TASK_ABORTED:
+ result |= DID_ABORT << 16 |
+ ABORT_TASK << 8 |
+ SAM_STAT_TASK_ABORTED;
+ break;
+ default:
+ result |= DID_ERROR << 16;
+ break;
+ } /* end of switch */
+
+ return result;
+}
+
+/**
+ * ufshcd_transfer_rsp_status - Get overall status of the response
+ * @hba: per adapter instance
+ * @lrb: pointer to local reference block of completed command
+ *
+ * Returns result of the command to notify SCSI midlayer
+ */
+static inline int
+ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+ int result = 0;
+ int scsi_status;
+ int ocs;
+
+ /* overall command status of utrd */
+ ocs = ufshcd_get_tr_ocs(lrbp);
+
+ switch (ocs) {
+ case OCS_SUCCESS:
+
+ /* check if the returned transfer response is valid */
+ result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
+ if (result) {
+ dev_err(&hba->pdev->dev,
+ "Invalid response = %x\n", result);
+ break;
+ }
+
+ /*
+ * get the response UPIU result to extract
+ * the SCSI command status
+ */
+ result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+ /*
+ * get the result based on SCSI status response
+ * to notify the SCSI midlayer of the command status
+ */
+ scsi_status = result & MASK_SCSI_STATUS;
+ result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+ break;
+ case OCS_ABORTED:
+ result |= DID_ABORT << 16 | ABORT_TASK << 8;
+ break;
+ case OCS_INVALID_CMD_TABLE_ATTR:
+ case OCS_INVALID_PRDT_ATTR:
+ case OCS_MISMATCH_DATA_BUF_SIZE:
+ case OCS_MISMATCH_RESP_UPIU_SIZE:
+ case OCS_PEER_COMM_FAILURE:
+ case OCS_FATAL_ERROR:
+ default:
+ result |= DID_ERROR << 16;
+ dev_err(&hba->pdev->dev,
+ "OCS error from controller = %x\n", ocs);
+ break;
+ } /* end of switch */
+
+ return result;
+}
+
+/**
+ * ufshcd_transfer_req_compl - handle SCSI and query command completion
+ * @hba: per adapter instance
+ */
+static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
+{
+ struct ufshcd_lrb *lrb;
+ unsigned long completed_reqs;
+ u32 tr_doorbell;
+ int result;
+ int index;
+
+ lrb = hba->lrb;
+ tr_doorbell =
+ readl(hba->mmio_base + REG_UTP_TRANSFER_REQ_DOOR_BELL);
+ completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
+
+ for (index = 0; index < hba->nutrs; index++) {
+ if (test_bit(index, &completed_reqs)) {
+
+ result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
+
+ if (lrb[index].cmd) {
+ scsi_dma_unmap(lrb[index].cmd);
+ lrb[index].cmd->result = result;
+ lrb[index].cmd->scsi_done(lrb[index].cmd);
+
+ /* Mark completed command as NULL in LRB */
+ lrb[index].cmd = NULL;
+ }
+ } /* end of if */
+ } /* end of for */
+
+ /* clear corresponding bits of completed commands */
+ hba->outstanding_reqs ^= completed_reqs;
+
+ /* Reset interrupt aggregation counters */
+ ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+}
+
+/**
* ufshcd_uic_cc_handler - handle UIC command completion
* @work: pointer to a work queue structure
*
@@ -773,6 +1256,9 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
{
if (intr_status & UIC_COMMAND_COMPL)
schedule_work(&hba->uic_workq);
+
+ if (intr_status & UTP_TRANSFER_REQ_COMPL)
+ ufshcd_transfer_req_compl(hba);
}

/**
@@ -809,7 +1295,13 @@ static struct scsi_host_template ufshcd_driver_template = {
.module = THIS_MODULE,
.name = UFSHCD,
.proc_name = UFSHCD,
+ .queuecommand = ufshcd_queuecommand,
+ .slave_alloc = ufshcd_slave_alloc,
+ .slave_destroy = ufshcd_slave_destroy,
.this_id = -1,
+ .sg_tablesize = SG_ALL,
+ .cmd_per_lun = UFSHCD_CMD_PER_LUN,
+ .can_queue = UFSHCD_CAN_QUEUE,
};

/**
@@ -1003,6 +1495,7 @@ ufshcd_probe(struct pci_dev *pdev, const struct pci_device_id *id)
host->max_lun = UFSHCD_MAX_LUNS;
host->max_channel = UFSHCD_MAX_CHANNEL;
host->unique_id = host->host_no;
+ host->max_cmd_len = MAX_CDB_SIZE;

/* Initialize work queues */
INIT_WORK(&hba->uic_workq, ufshcd_uic_cc_handler);
@@ -1014,6 +1507,13 @@ ufshcd_probe(struct pci_dev *pdev, const struct pci_device_id *id)
goto out_lrb_free;
}

+ /* Enable SCSI tag mapping */
+ err = scsi_init_shared_tag_map(host, host->can_queue);
+ if (err) {
+ dev_err(&pdev->dev, "init shared queue failed\n");
+ goto out_free_irq;
+ }
+
pci_set_drvdata(pdev, hba);

err = scsi_add_host(host, &pdev->dev);
--
1.7.5.4

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