ice: use same function to snapshot both NVM and Shadow RAM

The ice driver supports a region for both the flat NVM contents as well as
the Shadow RAM which is a layer built on top of the flash during device
initialization.

These regions use an almost identical read function, except that the NVM
needs to set the direct flag when reading, while Shadow RAM needs to read
without the direct flag set. They each call ice_read_flat_nvm with the only
difference being whether to set the direct flash flag.

The NVM region read function also was fixed to read the NVM in blocks to
avoid a situation where the firmware reclaims the lock due to taking too
long.

Note that the region snapshot function takes the ops pointer so the
function can easily determine which region to read. Make use of this and
re-use the NVM snapshot function for both the NVM and Shadow RAM regions.
This makes Shadow RAM benefit from the same block approach as the NVM
region. It also reduces code in the ice driver.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -1596,21 +1596,22 @@ void ice_devlink_destroy_vf_port(struct ice_vf *vf)
 
 #define ICE_DEVLINK_READ_BLK_SIZE (1024 * 1024)
 
+static const struct devlink_region_ops ice_nvm_region_ops;
+static const struct devlink_region_ops ice_sram_region_ops;
+
 /**
  * ice_devlink_nvm_snapshot - Capture a snapshot of the NVM flash contents
  * @devlink: the devlink instance
- * @ops: the devlink region being snapshotted
+ * @ops: the devlink region to snapshot
  * @extack: extended ACK response structure
  * @data: on exit points to snapshot data buffer
  *
- * This function is called in response to the DEVLINK_CMD_REGION_TRIGGER for
- * the nvm-flash devlink region. It captures a snapshot of the full NVM flash
- * contents, including both banks of flash. This snapshot can later be viewed
- * via the devlink-region interface.
+ * This function is called in response to a DEVLINK_CMD_REGION_NEW for either
+ * the nvm-flash or shadow-ram region.
  *
- * It captures the flash using the FLASH_ONLY bit set when reading via
- * firmware, so it does not read the current Shadow RAM contents. For that,
- * use the shadow-ram region.
+ * It captures a snapshot of the NVM or Shadow RAM flash contents. This
+ * snapshot can then later be viewed via the DEVLINK_CMD_REGION_READ netlink
+ * interface.
  *
  * @returns zero on success, and updates the data pointer. Returns a non-zero
  * error code on failure.
@@ -1622,17 +1623,27 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink,
 	struct ice_pf *pf = devlink_priv(devlink);
 	struct device *dev = ice_pf_to_dev(pf);
 	struct ice_hw *hw = &pf->hw;
+	bool read_shadow_ram;
 	u8 *nvm_data, *tmp, i;
 	u32 nvm_size, left;
 	s8 num_blks;
 	int status;
 
-	nvm_size = hw->flash.flash_size;
+	if (ops == &ice_nvm_region_ops) {
+		read_shadow_ram = false;
+		nvm_size = hw->flash.flash_size;
+	} else if (ops == &ice_sram_region_ops) {
+		read_shadow_ram = true;
+		nvm_size = hw->flash.sr_words * 2u;
+	} else {
+		NL_SET_ERR_MSG_MOD(extack, "Unexpected region in snapshot function");
+		return -EOPNOTSUPP;
+	}
+
 	nvm_data = vzalloc(nvm_size);
 	if (!nvm_data)
 		return -ENOMEM;
 
-
 	num_blks = DIV_ROUND_UP(nvm_size, ICE_DEVLINK_READ_BLK_SIZE);
 	tmp = nvm_data;
 	left = nvm_size;
@@ -1656,7 +1667,7 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink,
 		}
 
 		status = ice_read_flat_nvm(hw, i * ICE_DEVLINK_READ_BLK_SIZE,
-					   &read_sz, tmp, false);
+					   &read_sz, tmp, read_shadow_ram);
 		if (status) {
 			dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n",
 				read_sz, status, hw->adminq.sq_last_status);
@@ -1676,66 +1687,6 @@ static int ice_devlink_nvm_snapshot(struct devlink *devlink,
 	return 0;
 }
 
-/**
- * ice_devlink_sram_snapshot - Capture a snapshot of the Shadow RAM contents
- * @devlink: the devlink instance
- * @ops: the devlink region being snapshotted
- * @extack: extended ACK response structure
- * @data: on exit points to snapshot data buffer
- *
- * This function is called in response to the DEVLINK_CMD_REGION_TRIGGER for
- * the shadow-ram devlink region. It captures a snapshot of the shadow ram
- * contents. This snapshot can later be viewed via the devlink-region
- * interface.
- *
- * @returns zero on success, and updates the data pointer. Returns a non-zero
- * error code on failure.
- */
-static int
-ice_devlink_sram_snapshot(struct devlink *devlink,
-			  const struct devlink_region_ops __always_unused *ops,
-			  struct netlink_ext_ack *extack, u8 **data)
-{
-	struct ice_pf *pf = devlink_priv(devlink);
-	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_hw *hw = &pf->hw;
-	u8 *sram_data;
-	u32 sram_size;
-	int err;
-
-	sram_size = hw->flash.sr_words * 2u;
-	sram_data = vzalloc(sram_size);
-	if (!sram_data)
-		return -ENOMEM;
-
-	err = ice_acquire_nvm(hw, ICE_RES_READ);
-	if (err) {
-		dev_dbg(dev, "ice_acquire_nvm failed, err %d aq_err %d\n",
-			err, hw->adminq.sq_last_status);
-		NL_SET_ERR_MSG_MOD(extack, "Failed to acquire NVM semaphore");
-		vfree(sram_data);
-		return err;
-	}
-
-	/* Read from the Shadow RAM, rather than directly from NVM */
-	err = ice_read_flat_nvm(hw, 0, &sram_size, sram_data, true);
-	if (err) {
-		dev_dbg(dev, "ice_read_flat_nvm failed after reading %u bytes, err %d aq_err %d\n",
-			sram_size, err, hw->adminq.sq_last_status);
-		NL_SET_ERR_MSG_MOD(extack,
-				   "Failed to read Shadow RAM contents");
-		ice_release_nvm(hw);
-		vfree(sram_data);
-		return err;
-	}
-
-	ice_release_nvm(hw);
-
-	*data = sram_data;
-
-	return 0;
-}
-
 /**
  * ice_devlink_devcaps_snapshot - Capture snapshot of device capabilities
  * @devlink: the devlink instance
@@ -1789,7 +1740,7 @@ static const struct devlink_region_ops ice_nvm_region_ops = {
 static const struct devlink_region_ops ice_sram_region_ops = {
 	.name = "shadow-ram",
 	.destructor = vfree,
-	.snapshot = ice_devlink_sram_snapshot,
+	.snapshot = ice_devlink_nvm_snapshot,
 };
 
 static const struct devlink_region_ops ice_devcaps_region_ops = {