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>

drivers/net/ethernet/intel/ice/ice_common.h

@@ -28,6 +28,8 @@ ice_acquire_res(struct ice_hw *hw, enum ice_aq_res_ids res,
 		enum ice_aq_res_access_type access, u32 timeout);
 void ice_release_res(struct ice_hw *hw, enum ice_aq_res_ids res);
 enum ice_status ice_init_nvm(struct ice_hw *hw);
+enum ice_status ice_read_sr_buf(struct ice_hw *hw, u16 offset, u16 *words,
+				u16 *data);
 enum ice_status
 ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
 		struct ice_aq_desc *desc, void *buf, u16 buf_size,

drivers/net/ethernet/intel/ice/ice_ethtool.c

@@ -203,6 +203,55 @@ static void ice_set_msglevel(struct net_device *netdev, u32 data)
 #endif /* !CONFIG_DYNAMIC_DEBUG */
 }
 
+static int ice_get_eeprom_len(struct net_device *netdev)
+{
+	struct ice_netdev_priv *np = netdev_priv(netdev);
+	struct ice_pf *pf = np->vsi->back;
+
+	return (int)(pf->hw.nvm.sr_words * sizeof(u16));
+}
+
+static int
+ice_get_eeprom(struct net_device *netdev, struct ethtool_eeprom *eeprom,
+	       u8 *bytes)
+{
+	struct ice_netdev_priv *np = netdev_priv(netdev);
+	u16 first_word, last_word, nwords;
+	struct ice_vsi *vsi = np->vsi;
+	struct ice_pf *pf = vsi->back;
+	struct ice_hw *hw = &pf->hw;
+	enum ice_status status;
+	struct device *dev;
+	int ret = 0;
+	u16 *buf;
+
+	dev = &pf->pdev->dev;
+
+	eeprom->magic = hw->vendor_id | (hw->device_id << 16);
+
+	first_word = eeprom->offset >> 1;
+	last_word = (eeprom->offset + eeprom->len - 1) >> 1;
+	nwords = last_word - first_word + 1;
+
+	buf = devm_kcalloc(dev, nwords, sizeof(u16), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	status = ice_read_sr_buf(hw, first_word, &nwords, buf);
+	if (status) {
+		dev_err(dev, "ice_read_sr_buf failed, err %d aq_err %d\n",
+			status, hw->adminq.sq_last_status);
+		eeprom->len = sizeof(u16) * nwords;
+		ret = -EIO;
+		goto out;
+	}
+
+	memcpy(bytes, (u8 *)buf + (eeprom->offset & 1), eeprom->len);
+out:
+	devm_kfree(dev, buf);
+	return ret;
+}
+
 static void ice_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
 {
 	struct ice_netdev_priv *np = netdev_priv(netdev);
@@ -1699,6 +1748,8 @@ static const struct ethtool_ops ice_ethtool_ops = {
 	.get_msglevel           = ice_get_msglevel,
 	.set_msglevel           = ice_set_msglevel,
 	.get_link		= ethtool_op_get_link,
+	.get_eeprom_len		= ice_get_eeprom_len,
+	.get_eeprom		= ice_get_eeprom,
 	.get_strings		= ice_get_strings,
 	.set_phys_id		= ice_set_phys_id,
 	.get_ethtool_stats      = ice_get_ethtool_stats,

drivers/net/ethernet/intel/ice/ice_nvm.c

@@ -124,6 +124,62 @@ ice_read_sr_word_aq(struct ice_hw *hw, u16 offset, u16 *data)
 	return status;
 }
 
+/**
+ * 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
@@ -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;
+}