diff mbox series

[net-next,06/12] nfp: avoid reclaiming resource mutex by mistake

Message ID 20230724094821.14295-7-louis.peens@corigine.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series nfp: add support for multi-pf configuration | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
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: 1342 this patch: 1342
netdev/cc_maintainers warning 2 maintainers not CCed: edumazet@google.com niklas.soderlund@corigine.com
netdev/build_clang success Errors and warnings before: 1365 this patch: 1365
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: 1365 this patch: 1365
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Louis Peens July 24, 2023, 9:48 a.m. UTC 
From: Yinjun Zhang <yinjun.zhang@corigine.com>

Multiple PFs of the same controller use the same interface
id. So we shouldn't unconditionally reclaim resource mutex
when probing, because the mutex may be held by another PF
from the same controller.

Now give it some time to release the mutex, and reclaim it
if timeout.

Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
---
 .../netronome/nfp/nfpcore/nfp_mutex.c         | 21 +++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c
index 7bc17b94ac60..1b9170d9da77 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c
@@ -343,6 +343,7 @@  int nfp_cpp_mutex_reclaim(struct nfp_cpp *cpp, int target,
 {
 	const u32 mur = NFP_CPP_ID(target, 3, 0);	/* atomic_read */
 	const u32 muw = NFP_CPP_ID(target, 4, 0);	/* atomic_write */
+	unsigned long timeout = jiffies + 2 * HZ;
 	u16 interface = nfp_cpp_interface(cpp);
 	int err;
 	u32 tmp;
@@ -351,13 +352,21 @@  int nfp_cpp_mutex_reclaim(struct nfp_cpp *cpp, int target,
 	if (err)
 		return err;
 
-	/* Check lock */
-	err = nfp_cpp_readl(cpp, mur, address, &tmp);
-	if (err < 0)
-		return err;
+	/* Check lock. Note that PFs from the same controller use same interface ID.
+	 * So considering that the lock may be held by other PFs from the same
+	 * controller, we give it some time to release the lock, and only reclaim it
+	 * if timeout.
+	 */
+	while (time_is_after_jiffies(timeout)) {
+		err = nfp_cpp_readl(cpp, mur, address, &tmp);
+		if (err < 0)
+			return err;
 
-	if (nfp_mutex_is_unlocked(tmp) || nfp_mutex_owner(tmp) != interface)
-		return 0;
+		if (nfp_mutex_is_unlocked(tmp) || nfp_mutex_owner(tmp) != interface)
+			return 0;
+
+		msleep_interruptible(10);
+	}
 
 	/* Bust the lock */
 	err = nfp_cpp_writel(cpp, muw, address, nfp_mutex_unlocked(interface));