ufs: query descriptor API

Introduces the API for sending queries with descriptors.
A descriptor is a block or page of parameters that describe the device.
The descriptors are classified into types and can range in size
from 2 bytes through 255 bytes.
All descriptors have a length value as their first element, and a type
identification element as their second byte.
All descriptors are readable and some may be write once.
They are accessed using their type, index and selector.

Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Acked-by: Santosh Y <santoshsy@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

2 files changed, 128 insertions, 28 deletions

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index f42d1cee652a..1545cd7877d0 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -41,7 +41,8 @@
 
 #define MAX_CDB_SIZE    16
 #define GENERAL_UPIU_REQUEST_SIZE 32
-#define QUERY_DESC_MAX_SIZE       256
+#define QUERY_DESC_MAX_SIZE       255
+#define QUERY_DESC_MIN_SIZE       2
 #define QUERY_OSF_SIZE            (GENERAL_UPIU_REQUEST_SIZE - \
                                         (sizeof(struct utp_upiu_header)))
 
@@ -117,6 +118,20 @@ enum attr_idn {
         QUERY_ATTR_IDN_EE_STATUS        = 0x0E,
 };
 
+/* Descriptor idn for Query requests */
+enum desc_idn {
+        QUERY_DESC_IDN_DEVICE           = 0x0,
+        QUERY_DESC_IDN_CONFIGURAION     = 0x1,
+        QUERY_DESC_IDN_UNIT             = 0x2,
+        QUERY_DESC_IDN_RFU_0            = 0x3,
+        QUERY_DESC_IDN_INTERCONNECT     = 0x4,
+        QUERY_DESC_IDN_STRING           = 0x5,
+        QUERY_DESC_IDN_RFU_1            = 0x6,
+        QUERY_DESC_IDN_GEOMETRY         = 0x7,
+        QUERY_DESC_IDN_POWER            = 0x8,
+        QUERY_DESC_IDN_RFU_2            = 0x9,
+};
+
 /* Exception event mask values */
 enum {
         MASK_EE_STATUS          = 0xFFFF,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 0c2877251251..ed533f43f231 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -459,7 +459,7 @@ void ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 
         /* Get the descriptor */
         if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
-                u8 *descp = (u8 *)&lrbp->ucd_rsp_ptr +
+                u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
                                 GENERAL_UPIU_REQUEST_SIZE;
                 u16 len;
 
@@ -1134,6 +1134,30 @@ out_put_tag:
 }
 
 /**
+ * ufshcd_init_query() - init the query response and request parameters
+ * @hba: per-adapter instance
+ * @request: address of the request pointer to be initialized
+ * @response: address of the response pointer to be initialized
+ * @opcode: operation to perform
+ * @idn: flag idn to access
+ * @index: LU number to access
+ * @selector: query/flag/descriptor further identification
+ */
+static inline void ufshcd_init_query(struct ufs_hba *hba,
+                struct ufs_query_req **request, struct ufs_query_res **response,
+                enum query_opcode opcode, u8 idn, u8 index, u8 selector)
+{
+        *request = &hba->dev_cmd.query.request;
+        *response = &hba->dev_cmd.query.response;
+        memset(*request, 0, sizeof(struct ufs_query_req));
+        memset(*response, 0, sizeof(struct ufs_query_res));
+        (*request)->upiu_req.opcode = opcode;
+        (*request)->upiu_req.idn = idn;
+        (*request)->upiu_req.index = index;
+        (*request)->upiu_req.selector = selector;
+}
+
+/**
  * ufshcd_query_flag() - API function for sending flag query requests
  * hba: per-adapter instance
  * query_opcode: flag query to perform
@@ -1145,17 +1169,15 @@ out_put_tag:
 static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
                         enum flag_idn idn, bool *flag_res)
 {
-        struct ufs_query_req *request;
-        struct ufs_query_res *response;
-        int err;
+        struct ufs_query_req *request = NULL;
+        struct ufs_query_res *response = NULL;
+        int err, index = 0, selector = 0;
 
         BUG_ON(!hba);
 
         mutex_lock(&hba->dev_cmd.lock);
-        request = &hba->dev_cmd.query.request;
-        response = &hba->dev_cmd.query.response;
-        memset(request, 0, sizeof(struct ufs_query_req));
-        memset(response, 0, sizeof(struct ufs_query_res));
+        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+                        selector);
 
         switch (opcode) {
         case UPIU_QUERY_OPCODE_SET_FLAG:
@@ -1180,12 +1202,8 @@ static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
                 err = -EINVAL;
                 goto out_unlock;
         }
-        request->upiu_req.opcode = opcode;
-        request->upiu_req.idn = idn;
 
-        /* Send query request */
-        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY,
-                        QUERY_REQ_TIMEOUT);
+        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
 
         if (err) {
                 dev_err(hba->dev,
@@ -1217,8 +1235,8 @@ out_unlock:
 static int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
                         enum attr_idn idn, u8 index, u8 selector, u32 *attr_val)
 {
-        struct ufs_query_req *request;
-        struct ufs_query_res *response;
+        struct ufs_query_req *request = NULL;
+        struct ufs_query_res *response = NULL;
         int err;
 
         BUG_ON(!hba);
@@ -1231,10 +1249,8 @@ static int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
         }
 
         mutex_lock(&hba->dev_cmd.lock);
-        request = &hba->dev_cmd.query.request;
-        response = &hba->dev_cmd.query.response;
-        memset(request, 0, sizeof(struct ufs_query_req));
-        memset(response, 0, sizeof(struct ufs_query_res));
+        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+                        selector);
 
         switch (opcode) {
         case UPIU_QUERY_OPCODE_WRITE_ATTR:
@@ -1251,14 +1267,7 @@ static int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
                 goto out_unlock;
         }
 
-        request->upiu_req.opcode = opcode;
-        request->upiu_req.idn = idn;
-        request->upiu_req.index = index;
-        request->upiu_req.selector = selector;
-
-        /* Send query request */
-        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY,
-                                                QUERY_REQ_TIMEOUT);
+        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
 
         if (err) {
                 dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
@@ -1275,6 +1284,82 @@ out:
 }
 
 /**
+ * ufshcd_query_descriptor - API function for sending descriptor requests
+ * hba: per-adapter instance
+ * opcode: attribute opcode
+ * idn: attribute idn to access
+ * index: index field
+ * selector: selector field
+ * desc_buf: the buffer that contains the descriptor
+ * buf_len: length parameter passed to the device
+ *
+ * Returns 0 for success, non-zero in case of failure.
+ * The buf_len parameter will contain, on return, the length parameter
+ * received on the response.
+ */
+int ufshcd_query_descriptor(struct ufs_hba *hba,
+                        enum query_opcode opcode, enum desc_idn idn, u8 index,
+                        u8 selector, u8 *desc_buf, int *buf_len)
+{
+        struct ufs_query_req *request = NULL;
+        struct ufs_query_res *response = NULL;
+        int err;
+
+        BUG_ON(!hba);
+
+        if (!desc_buf) {
+                dev_err(hba->dev, "%s: descriptor buffer required for opcode 0x%x\n",
+                                __func__, opcode);
+                err = -EINVAL;
+                goto out;
+        }
+
+        if (*buf_len <= QUERY_DESC_MIN_SIZE || *buf_len > QUERY_DESC_MAX_SIZE) {
+                dev_err(hba->dev, "%s: descriptor buffer size (%d) is out of range\n",
+                                __func__, *buf_len);
+                err = -EINVAL;
+                goto out;
+        }
+
+        mutex_lock(&hba->dev_cmd.lock);
+        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
+                        selector);
+        hba->dev_cmd.query.descriptor = desc_buf;
+        request->upiu_req.length = *buf_len;
+
+        switch (opcode) {
+        case UPIU_QUERY_OPCODE_WRITE_DESC:
+                request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+                break;
+        case UPIU_QUERY_OPCODE_READ_DESC:
+                request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+                break;
+        default:
+                dev_err(hba->dev,
+                                "%s: Expected query descriptor opcode but got = 0x%.2x\n",
+                                __func__, opcode);
+                err = -EINVAL;
+                goto out_unlock;
+        }
+
+        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
+
+        if (err) {
+                dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
+                                __func__, opcode, idn, err);
+                goto out_unlock;
+        }
+
+        hba->dev_cmd.query.descriptor = NULL;
+        *buf_len = response->upiu_res.length;
+
+out_unlock:
+        mutex_unlock(&hba->dev_cmd.lock);
+out:
+        return err;
+}
+
+/**
  * ufshcd_memory_alloc - allocate memory for host memory space data structures
  * @hba: per adapter instance
  *