diff mbox series

[iwl-next,v2,13/13] ice: cleanup Rx queue context programming functions

Message ID 20240828-e810-live-migration-jk-prep-ctx-functions-v2-13-558ab9e240f5@intel.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series ice: use <linux/packing.h> for Tx and Rx queue context data | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 3 maintainers not CCed: pabeni@redhat.com kuba@kernel.org edumazet@google.com
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 74 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 220 this patch: 216
netdev/source_inline success Was 0 now: 0

Commit Message

Keller, Jacob E Aug. 28, 2024, 8:57 p.m. UTC
The ice_copy_rxq_ctx_to_hw() and ice_write_rxq_ctx() functions perform some
defensive checks which are typically frowned upon by kernel style
guidelines.

In particular, they perform NULL checks on buffers which are never expected
to be NULL. Both functions are only called once and always have valid
buffers pointing to stack memory. These checks only serve to hide potential
programming error, as we will not produce the normal crash dump on a NULL
access.

In addition, ice_copy_rxq_ctx_to_hw() cannot fail in another way, so could
be made void.

Future support for VF Live Migration will need to introduce an inverse
function for reading Rx queue context from HW registers to unpack it, as
well as functions to pack and unpack Tx queue context from HW.

Rather than copying these style issues into the new functions, lets first
cleanup the existing code.

For the ice_copy_rxq_ctx_to_hw() function:

 * Remove the NULL parameter check.
 * Move the Rx queue index check out of this function.
 * Convert the function to a void return.
 * Use a simple int variable instead of a u8 for the for loop index.
 * Use a local variable and array syntax to access the rxq_ctx.
 * Update the function description to better align with kernel doc style.

For the ice_write_rxq_ctx() function:

 * Use the more common '= {}' syntax for initializing the context buffer.
 * Move the Rx queue index check into this function.
 * Update the function description with a Returns: to align with kernel doc
   style.

These changes align the existing write functions to current kernel
style, and will align with the style of the new functions added when we
implement live migration in a future series.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_common.c | 42 ++++++++++++-----------------
 1 file changed, 17 insertions(+), 25 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index 67273e4af7ff..bf4f4b6195f9 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -1357,34 +1357,22 @@  int ice_reset(struct ice_hw *hw, enum ice_reset_req req)
 }
 
 /**
- * ice_copy_rxq_ctx_to_hw
+ * ice_copy_rxq_ctx_to_hw - Copy packed Rx queue context to HW registers
  * @hw: pointer to the hardware structure
- * @ice_rxq_ctx: pointer to the rxq context
+ * @rxq_ctx: pointer to the packed Rx queue context
  * @rxq_index: the index of the Rx queue
- *
- * Copies rxq context from dense structure to HW register space
  */
-static int
-ice_copy_rxq_ctx_to_hw(struct ice_hw *hw, u8 *ice_rxq_ctx, u32 rxq_index)
+static void ice_copy_rxq_ctx_to_hw(struct ice_hw *hw, u8 *rxq_ctx,
+				   u32 rxq_index)
 {
-	u8 i;
-
-	if (!ice_rxq_ctx)
-		return -EINVAL;
-
-	if (rxq_index > QRX_CTRL_MAX_INDEX)
-		return -EINVAL;
-
 	/* Copy each dword separately to HW */
-	for (i = 0; i < ICE_RXQ_CTX_SIZE_DWORDS; i++) {
-		wr32(hw, QRX_CONTEXT(i, rxq_index),
-		     *((u32 *)(ice_rxq_ctx + (i * sizeof(u32)))));
+	for (int i = 0; i < ICE_RXQ_CTX_SIZE_DWORDS; i++) {
+		u32 ctx = ((u32 *)rxq_ctx)[i];
 
-		ice_debug(hw, ICE_DBG_QCTX, "qrxdata[%d]: %08X\n", i,
-			  *((u32 *)(ice_rxq_ctx + (i * sizeof(u32)))));
+		wr32(hw, QRX_CONTEXT(i, rxq_index), ctx);
+
+		ice_debug(hw, ICE_DBG_QCTX, "qrxdata[%d]: %08X\n", i, ctx);
 	}
-
-	return 0;
 }
 
 /**
@@ -1497,23 +1485,27 @@  const struct ice_ctx_ele ice_rlan_ctx_info[] = {
 /**
  * ice_write_rxq_ctx - Write Rx Queue context to hardware
  * @hw: pointer to the hardware structure
- * @rlan_ctx: pointer to the rxq context
+ * @rlan_ctx: pointer to the packed Rx queue context
  * @rxq_index: the index of the Rx queue
  *
  * Pack the sparse Rx Queue context into dense hardware format and write it
  * into the HW register space.
+ *
+ * Return: 0 on success, or -EINVAL if the Rx queue index is invalid.
  */
 int ice_write_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
 		      u32 rxq_index)
 {
-	u8 ctx_buf[ICE_RXQ_CTX_SZ] = { 0 };
+	u8 ctx_buf[ICE_RXQ_CTX_SZ] = {};
 
-	if (!rlan_ctx)
+	if (rxq_index > QRX_CTRL_MAX_INDEX)
 		return -EINVAL;
 
 	ice_pack_rxq_ctx(rlan_ctx, ctx_buf);
 
-	return ice_copy_rxq_ctx_to_hw(hw, ctx_buf, rxq_index);
+	ice_copy_rxq_ctx_to_hw(hw, ctx_buf, rxq_index);
+
+	return 0;
 }
 
 /* LAN Tx Queue Context */