ice: Implement support for normal get_eeprom[_len] ethtool ops

Add support for get_eeprom and get_eeprom_len ethtool ops

Specification states that PF software accesses NVM (shadow-ram) via AQ
commands (e.g. NVM Read, NVM Write) in the range 0x000000-0x00FFFF (64KB),
so the get_eeprom_len op should return 64KB.  If additional regions of the
16MB NVM must be read, another access method must be used.

The ethtool kernel code, by default, will ask for multiple page-size hunks
of the NVM not to exceed the value returned by ice_get_eeprom_len().
ice_read_sr_buf() deals with arch page sizes different than 4KB.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.c b/drivers/net/ethernet/intel/ice/ice_nvm.c
index 3274c543283c..ce64cecdae9c 100644
--- a/drivers/net/ethernet/intel/ice/ice_nvm.c
+++ b/drivers/net/ethernet/intel/ice/ice_nvm.c
@@ -125,6 +125,62 @@ ice_read_sr_word_aq(struct ice_hw *hw, u16 offset, u16 *data)
 }
 
 /**
+ * ice_read_sr_buf_aq - Reads Shadow RAM buf via AQ
+ * @hw: pointer to the HW structure
+ * @offset: offset of the Shadow RAM word to read (0x000000 - 0x001FFF)
+ * @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.
+ */
+static enum ice_status
+ice_read_sr_buf_aq(struct ice_hw *hw, u16 offset, u16 *words, u16 *data)
+{
+	enum ice_status status;
+	bool last_cmd = false;
+	u16 words_read = 0;
+	u16 i = 0;
+
+	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(*words,
+			    (u16)(ICE_SR_SECTOR_SIZE_IN_WORDS - off_w)) :
+			min((*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;
+
+		/* Increment counter for words already read and move offset to
+		 * new read location
+		 */
+		words_read += read_size;
+		offset += read_size;
+	} while (words_read < *words);
+
+	for (i = 0; i < *words; i++)
+		data[i] = le16_to_cpu(((__le16 *)data)[i]);
+
+read_nvm_buf_aq_exit:
+	*words = words_read;
+	return status;
+}
+
+/**
  * ice_acquire_nvm - Generic request for acquiring the NVM ownership
  * @hw: pointer to the HW structure
  * @access: NVM access type (read or write)
@@ -234,3 +290,28 @@ enum ice_status ice_init_nvm(struct ice_hw *hw)
 
 	return status;
 }
+
+/**
+ * ice_read_sr_buf - Reads Shadow RAM buf and acquire lock if necessary
+ * @hw: pointer to the HW structure
+ * @offset: offset of the Shadow RAM word to read (0x000000 - 0x001FFF)
+ * @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_nvm_buf_aq
+ * method. The buf read is preceded by the NVM ownership take
+ * and followed by the release.
+ */
+enum ice_status
+ice_read_sr_buf(struct ice_hw *hw, u16 offset, u16 *words, u16 *data)
+{
+	enum ice_status status;
+
+	status = ice_acquire_nvm(hw, ICE_RES_READ);
+	if (!status) {
+		status = ice_read_sr_buf_aq(hw, offset, words, data);
+		ice_release_nvm(hw);
+	}
+
+	return status;
+}