The UFS host software uses a combination of a host register set,
and Transfer Request Descriptors in system memory to communicate
with host controller hardware. In its mmio space, a separate places
are assigned to UTP Transfer Request Descriptor ("utrd") list, and
to UTP Task Management Request Descriptor ("utmrd") list.

The provided API supports utrd-typed requests: nop out
and device management commands. It also supports utmrd-type
requests: task management requests.
Other UPIU types are not supported for now.

We utilize the already existing code for tag and task work queues.
That is, all utrd-typed UPIUs are "disguised" as device management
commands. Similarly, the utmrd-typed UPUIs uses the task management
infrastructure.

It is up to the caller to fill the upiu request properly,
as it will be copied without any further input validations.

Signed-off-by: Avri Altman <avri.alt...@wdc.com>
Reviewed-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Bart Van Assche <bart.vanass...@wdc.com>
---
 drivers/scsi/ufs/ufs.h    |   1 +
 drivers/scsi/ufs/ufshcd.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.h |   7 ++
 3 files changed, 184 insertions(+)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index f5800c32..58087d3 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -414,6 +414,7 @@ enum {
        MASK_RSP_UPIU_DATA_SEG_LEN      = 0xFFFF,
        MASK_RSP_EXCEPTION_EVENT        = 0x10000,
        MASK_TM_SERVICE_RESP            = 0xFF,
+       MASK_TM_FUNC                    = 0xFF,
 };
 
 /* Task management service response */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ccad830..9515bc7 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5676,6 +5676,182 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int 
lun_id, int task_id,
 }
 
 /**
+ * ufshcd_issue_devman_upiu_cmd - API for sending "utrd" type requests
+ * @hba:       per-adapter instance
+ * @req_upiu:  upiu request
+ * @rsp_upiu:  upiu reply
+ * @msgcode:   message code, one of UPIU Transaction Codes Initiator to Target
+ * @desc_buff: pointer to descriptor buffer, NULL if NA
+ * @buff_len:  descriptor size, 0 if NA
+ * @desc_op:   descriptor operation
+ *
+ * Those type of requests uses UTP Transfer Request Descriptor - utrd.
+ * Therefore, it "rides" the device management infrastructure: uses its tag and
+ * tasks work queues.
+ *
+ * Since there is only one available tag for device management commands,
+ * the caller is expected to hold the hba->dev_cmd.lock mutex.
+ */
+static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
+                                       struct utp_upiu_req *req_upiu,
+                                       struct utp_upiu_req *rsp_upiu,
+                                       u8 *desc_buff, int *buff_len,
+                                       int cmd_type,
+                                       enum query_opcode desc_op)
+{
+       struct ufshcd_lrb *lrbp;
+       int err = 0;
+       int tag;
+       struct completion wait;
+       unsigned long flags;
+       u32 upiu_flags;
+
+       down_read(&hba->clk_scaling_lock);
+
+       wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+       init_completion(&wait);
+       lrbp = &hba->lrb[tag];
+       WARN_ON(lrbp->cmd);
+
+       lrbp->cmd = NULL;
+       lrbp->sense_bufflen = 0;
+       lrbp->sense_buffer = NULL;
+       lrbp->task_tag = tag;
+       lrbp->lun = 0;
+       lrbp->intr_cmd = true;
+       hba->dev_cmd.type = cmd_type;
+
+       switch (hba->ufs_version) {
+       case UFSHCI_VERSION_10:
+       case UFSHCI_VERSION_11:
+               lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+               break;
+       default:
+               lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;
+               break;
+       }
+
+       /* update the task tag in the request upiu */
+       req_upiu->header.dword_0 |= cpu_to_be32(tag);
+
+       ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+
+       /* just copy the upiu request as it is */
+       memcpy(lrbp->ucd_req_ptr, req_upiu, sizeof(*lrbp->ucd_req_ptr));
+       if (desc_buff && desc_op == UPIU_QUERY_OPCODE_WRITE_DESC) {
+               /* The Data Segment Area is optional depending upon the query
+                * function value. for WRITE DESCRIPTOR, the data segment
+                * follows right after the tsf.
+                */
+               memcpy(lrbp->ucd_req_ptr + 1, desc_buff, *buff_len);
+               *buff_len = 0;
+       }
+
+       memset(lrbp->ucd_rsp_ptr, 0, sizeof(struct utp_upiu_rsp));
+
+       hba->dev_cmd.complete = &wait;
+
+       /* Make sure descriptors are ready before ringing the doorbell */
+       wmb();
+       spin_lock_irqsave(hba->host->host_lock, flags);
+       ufshcd_send_command(hba, tag);
+       spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+       /*
+        * ignore the returning value here - ufshcd_check_query_response is
+        * bound to fail since dev_cmd.query and dev_cmd.type were left empty.
+        * read the response directly ignoring all errors.
+        */
+       ufshcd_wait_for_dev_cmd(hba, lrbp, QUERY_REQ_TIMEOUT);
+
+       /* just copy the upiu response as it is */
+       memcpy(rsp_upiu, lrbp->ucd_rsp_ptr, sizeof(*rsp_upiu));
+
+       ufshcd_put_dev_cmd_tag(hba, tag);
+       wake_up(&hba->dev_cmd.tag_wq);
+       up_read(&hba->clk_scaling_lock);
+       return err;
+}
+
+/**
+ * ufshcd_exec_raw_upiu_cmd - API function for sending raw upiu commands
+ * @hba:       per-adapter instance
+ * @req_upiu:  upiu request
+ * @rsp_upiu:  upiu reply - only 8 DW as we do not support scsi commands
+ * @msgcode:   message code, one of UPIU Transaction Codes Initiator to Target
+ * @desc_buff: pointer to descriptor buffer, NULL if NA
+ * @buff_len:  descriptor size, 0 if NA
+ * @desc_op:   descriptor operation
+ *
+ * Supports UTP Transfer requests (nop and query), and UTP Task
+ * Management requests.
+ * It is up to the caller to fill the upiu conent properly, as it will
+ * be copied without any further input validations.
+ */
+int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
+                            struct utp_upiu_req *req_upiu,
+                            struct utp_upiu_req *rsp_upiu,
+                            int msgcode,
+                            u8 *desc_buff, int *buff_len,
+                            enum query_opcode desc_op)
+{
+       int err;
+       int cmd_type = DEV_CMD_TYPE_QUERY;
+       struct utp_task_req_desc treq = { { 0 }, };
+       int ocs_value;
+       u8 tm_f = be32_to_cpu(req_upiu->header.dword_1) >> 16 & MASK_TM_FUNC;
+
+       if (desc_buff && desc_op != UPIU_QUERY_OPCODE_WRITE_DESC) {
+               err = -ENOTSUPP;
+               goto out;
+       }
+
+       switch (msgcode) {
+       case UPIU_TRANSACTION_NOP_OUT:
+               cmd_type = DEV_CMD_TYPE_NOP;
+               /* fall through */
+       case UPIU_TRANSACTION_QUERY_REQ:
+               ufshcd_hold(hba, false);
+               mutex_lock(&hba->dev_cmd.lock);
+               err = ufshcd_issue_devman_upiu_cmd(hba, req_upiu, rsp_upiu,
+                                                  desc_buff, buff_len,
+                                                  cmd_type, desc_op);
+               mutex_unlock(&hba->dev_cmd.lock);
+               ufshcd_release(hba);
+
+               break;
+       case UPIU_TRANSACTION_TASK_REQ:
+               treq.header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
+               treq.header.dword_2 = cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+
+               memcpy(&treq.req_header, req_upiu, sizeof(*req_upiu));
+
+               err = __ufshcd_issue_tm_cmd(hba, &treq, tm_f);
+               if (err == -ETIMEDOUT)
+                       break;
+
+               ocs_value = le32_to_cpu(treq.header.dword_2) & MASK_OCS;
+               if (ocs_value != OCS_SUCCESS) {
+                       dev_err(hba->dev, "%s: failed, ocs = 0x%x\n", __func__,
+                               ocs_value);
+                       break;
+               }
+
+               memcpy(rsp_upiu, &treq.rsp_header, sizeof(*rsp_upiu));
+
+               break;
+       default:
+               err = -EINVAL;
+
+               break;
+       }
+
+out:
+       return err;
+}
+
+/**
  * ufshcd_eh_device_reset_handler - device reset handler registered to
  *                                    scsi layer.
  * @cmd: SCSI command pointer
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 54e6fe8..0878134 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -895,6 +895,13 @@ int ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum 
desc_idn desc_id,
 
 u32 ufshcd_get_local_unipro_ver(struct ufs_hba *hba);
 
+int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
+                            struct utp_upiu_req *req_upiu,
+                            struct utp_upiu_req *rsp_upiu,
+                            int msgcode,
+                            u8 *desc_buff, int *buff_len,
+                            enum query_opcode desc_op);
+
 /* Wrapper functions for safely calling variant operations */
 static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
 {
-- 
1.9.1

Reply via email to