net/ice/base: extract logic of flat NVM read to function

The ice_read_sr_buf_aq function implements logic to correctly break
apart NVM reads into 4Kb chunks. Additionally, it ensures that each read
never crosses a Shadow RAM sector boundary. This logic is useful when
reading the flat NVM as a byte-addressable stream.

Extract that logic in terms of bytes and implement it as
ice_read_flat_nvm. Use this new function to implement ice_read_sr_buf_aq
function.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Qiming Yang <qiming.yang@intel.com>

diff --git a/drivers/net/ice/base/ice_nvm.c b/drivers/net/ice/base/ice_nvm.c
index 5dd702d..80420af 100644 (file)
--- a/drivers/net/ice/base/ice_nvm.c
+++ b/drivers/net/ice/base/ice_nvm.c
@@ -49,6 +49,74 @@ ice_aq_read_nvm(struct ice_hw *hw, u16 module_typeid, u32 offset, u16 length,
        return ice_aq_send_cmd(hw, &desc, data, length, cd);
 }
 
+/**
+ * ice_read_flat_nvm - Read portion of NVM by flat offset
+ * @hw: pointer to the HW struct
+ * @offset: offset from beginning of NVM
+ * @length: (in) number of bytes to read; (out) number of bytes actually read
+ * @data: buffer to return data in (sized to fit the specified length)
+ * @read_shadow_ram: if true, read from shadow RAM instead of NVM
+ *
+ * Reads a portion of the NVM, as a flat memory space. This function correctly
+ * breaks read requests across Shadow RAM sectors and ensures that no single
+ * read request exceeds the maximum 4Kb read for a single AdminQ command.
+ *
+ * Returns a status code on failure. Note that the data pointer may be
+ * partially updated if some reads succeed before a failure.
+ */
+enum ice_status
+ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
+                 bool read_shadow_ram)
+{
+       enum ice_status status;
+       u32 inlen = *length;
+       u32 bytes_read = 0;
+       bool last_cmd;
+
+       ice_debug(hw, ICE_DBG_TRACE, "%s\n", __func__);
+
+       *length = 0;
+
+       /* Verify the length of the read if this is for the Shadow RAM */
+       if (read_shadow_ram && ((offset + inlen) > (hw->nvm.sr_words * 2u))) {
+               ice_debug(hw, ICE_DBG_NVM,
+                         "NVM error: requested data is beyond Shadow RAM limit\n");
+               return ICE_ERR_PARAM;
+       }
+
+       do {
+               u32 read_size, sector_offset;
+
+               /* ice_aq_read_nvm cannot read more than 4Kb at a time.
+                * Additionally, a read from the Shadow RAM may not cross over
+                * a sector boundary. Conveniently, the sector size is also
+                * 4Kb.
+                */
+               sector_offset = offset % ICE_AQ_MAX_BUF_LEN;
+               read_size = MIN_T(u32, ICE_AQ_MAX_BUF_LEN - sector_offset,
+                                 inlen - bytes_read);
+
+               last_cmd = !(bytes_read + read_size < inlen);
+
+               /* ice_aq_read_nvm takes the length as a u16. Our read_size is
+                * calculated using a u32, but the ICE_AQ_MAX_BUF_LEN maximum
+                * size guarantees that it will fit within the 2 bytes.
+                */
+               status = ice_aq_read_nvm(hw, ICE_AQC_NVM_START_POINT,
+                                        offset, (u16)read_size,
+                                        data + bytes_read, last_cmd,
+                                        read_shadow_ram, NULL);
+               if (status)
+                       break;
+
+               bytes_read += read_size;
+               offset += read_size;
+       } while (!last_cmd);
+
+       *length = bytes_read;
+       return status;
+}
+
 /**
  * ice_check_sr_access_params - verify params for Shadow RAM R/W operations.
  * @hw: pointer to the HW structure
@@ -144,55 +212,29 @@ ice_read_sr_word_aq(struct ice_hw *hw, u16 offset, u16 *data)
  * @words: (in) number of words to read; (out) number of words actually read
  * @data: words read from the Shadow RAM
  *
- * Reads 16 bit words (data buf) from the SR using the ice_read_sr_aq
- * method. Ownership of the NVM is taken before reading the buffer and later
- * released.
+ * Reads 16 bit words (data buf) from the Shadow RAM. Ownership of the NVM is
+ * taken before reading the buffer and later released.
  */
 static enum ice_status
 ice_read_sr_buf_aq(struct ice_hw *hw, u16 offset, u16 *words, u16 *data)
 {
+       u32 bytes = *words * 2, i;
        enum ice_status status;
-       bool last_cmd = false;
-       u16 words_read = 0;
-       u16 i = 0;
 
        ice_debug(hw, ICE_DBG_TRACE, "%s\n", __func__);
 
-       do {
-               u16 read_size, off_w;
-
-               /* Calculate number of bytes we should read in this step.
-                * It's not allowed to read more than one page at a time or
-                * to cross page boundaries.
-                */
-               off_w = offset % ICE_SR_SECTOR_SIZE_IN_WORDS;
-               read_size = off_w ?
-                       MIN_T(u16, *words,
-                             (ICE_SR_SECTOR_SIZE_IN_WORDS - off_w)) :
-                       MIN_T(u16, (*words - words_read),
-                             ICE_SR_SECTOR_SIZE_IN_WORDS);
-
-               /* Check if this is last command, if so set proper flag */
-               if ((words_read + read_size) >= *words)
-                       last_cmd = true;
-
-               status = ice_read_sr_aq(hw, offset, read_size,
-                                       data + words_read, last_cmd);
-               if (status)
-                       goto read_nvm_buf_aq_exit;
+       /* ice_read_flat_nvm takes into account the 4Kb AdminQ and Shadow RAM
+        * sector restrictions necessary when reading from the NVM.
+        */
+       status = ice_read_flat_nvm(hw, offset * 2, &bytes, (u8 *)data, true);
 
-               /* Increment counter for words already read and move offset to
-                * new read location
-                */
-               words_read += read_size;
-               offset += read_size;
-       } while (words_read < *words);
+       /* Report the number of words successfully read */
+       *words = bytes / 2;
 
+       /* Byte swap the words up to the amount we actually read */
        for (i = 0; i < *words; i++)
                data[i] = LE16_TO_CPU(((_FORCE_ __le16 *)data)[i]);
 
-read_nvm_buf_aq_exit:
-       *words = words_read;
        return status;
 }
 

diff --git a/drivers/net/ice/base/ice_nvm.h b/drivers/net/ice/base/ice_nvm.h
index d5b7b2d..8dbda82 100644 (file)
--- a/drivers/net/ice/base/ice_nvm.h
+++ b/drivers/net/ice/base/ice_nvm.h
@@ -84,6 +84,9 @@ ice_nvm_access_get_features(struct ice_nvm_access_cmd *cmd,
 enum ice_status
 ice_handle_nvm_access(struct ice_hw *hw, struct ice_nvm_access_cmd *cmd,
                      union ice_nvm_access_data *data);
+enum ice_status
+ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
+                 bool read_shadow_ram);
 enum ice_status ice_init_nvm(struct ice_hw *hw);
 enum ice_status ice_read_sr_word(struct ice_hw *hw, u16 offset, u16 *data);
 enum ice_status