diff mbox series

[v6,net-next,10/12] net: enetc: optimize the allocation of tx_bdr

Message ID 20241030093924.1251343-11-wei.fang@nxp.com (mailing list archive)
State Accepted
Commit 9e7f2116199d5b88e9fa6375a3b3aba4c6e08895
Delegated to: Netdev Maintainers
Headers show
Series add basic support for i.MX95 NETC | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
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: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: andrew+netdev@lunn.ch
netdev/build_clang success Errors and warnings before: 3 this patch: 3
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: 5 this patch: 5
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-11-02--06-00 (tests: 779)

Commit Message

Wei Fang Oct. 30, 2024, 9:39 a.m. UTC 
From: Clark Wang <xiaoning.wang@nxp.com>

There is a situation where num_tx_rings cannot be divided by bdr_int_num.
For example, num_tx_rings is 8 and bdr_int_num is 3. According to the
previous logic, this results in two tx_bdr corresponding memories not
being allocated, so when sending packets to tx ring 6 or 7, wild pointers
will be accessed. Of course, this issue doesn't exist on LS1028A, because
its num_tx_rings is 8, and bdr_int_num is either 1 or 2. However, there
is a risk for the upcoming i.MX95. Therefore, it is necessary to ensure
that each tx_bdr can be allocated to the corresponding memory.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
v6: only add a opening comment in the code
---
 drivers/net/ethernet/freescale/enetc/enetc.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index f292c5ef27b7..89d919c713df 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -3084,10 +3084,10 @@  static void enetc_int_vector_destroy(struct enetc_ndev_priv *priv, int i)
 int enetc_alloc_msix(struct enetc_ndev_priv *priv)
 {
 	struct pci_dev *pdev = priv->si->pdev;
+	int v_tx_rings, v_remainder;
 	int num_stack_tx_queues;
 	int first_xdp_tx_ring;
 	int i, n, err, nvec;
-	int v_tx_rings;
 
 	nvec = ENETC_BDR_INT_BASE_IDX + priv->bdr_int_num;
 	/* allocate MSIX for both messaging and Rx/Tx interrupts */
@@ -3101,9 +3101,15 @@  int enetc_alloc_msix(struct enetc_ndev_priv *priv)
 
 	/* # of tx rings per int vector */
 	v_tx_rings = priv->num_tx_rings / priv->bdr_int_num;
+	v_remainder = priv->num_tx_rings % priv->bdr_int_num;
 
 	for (i = 0; i < priv->bdr_int_num; i++) {
-		err = enetc_int_vector_init(priv, i, v_tx_rings);
+		/* Distribute the remaining TX rings to the first v_remainder
+		 * interrupt vectors
+		 */
+		int num_tx_rings = i < v_remainder ? v_tx_rings + 1 : v_tx_rings;
+
+		err = enetc_int_vector_init(priv, i, num_tx_rings);
 		if (err)
 			goto fail;
 	}