CPP mutex cache was introduced to work around the fact that the
same host could successfully acquire a lock multiple times. It
used to collapse multiple users to the same struct nfp_cpp_mutex
and track use count. Unfortunately it's racy. Since we now force
all nfp_mutex_lock() callers within the host to actually succeed
at acquiring the lock we no longer need the cache, let's remove it.
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
.../ethernet/netronome/nfp/nfpcore/nfp_cppcore.c | 43 +---------------------
1 file changed, 2 insertions(+), 41 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
index e2267b421af0..6337342c5b62 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c
@@ -66,10 +66,8 @@ struct nfp_cpp_resource {
};
struct nfp_cpp_mutex {
- struct list_head list;
struct nfp_cpp *cpp;
int target;
- u16 usage;
u16 depth;
unsigned long long address;
u32 key;
@@ -86,7 +84,6 @@ struct nfp_cpp {
const struct nfp_cpp_operations *op;
struct list_head resource_list; /* NFP CPP resource list */
- struct list_head mutex_cache; /* Mutex cache */
rwlock_t resource_lock;
wait_queue_head_t waitq;
@@ -187,24 +184,6 @@ void nfp_cpp_free(struct nfp_cpp *cpp)
{
struct nfp_cpp_area_cache *cache, *ctmp;
struct nfp_cpp_resource *res, *rtmp;
- struct nfp_cpp_mutex *mutex, *mtmp;
-
- /* There should be no mutexes in the cache at this point. */
- WARN_ON(!list_empty(&cpp->mutex_cache));
- /* .. but if there are, unlock them and complain. */
- list_for_each_entry_safe(mutex, mtmp, &cpp->mutex_cache, list) {
- dev_err(cpp->dev.parent, "Dangling mutex: @%d::0x%llx, %d locks
held by %d owners\n",
- mutex->target, (unsigned long long)mutex->address,
- mutex->depth, mutex->usage);
-
- /* Forcing an unlock */
- mutex->depth = 1;
- nfp_cpp_mutex_unlock(mutex);
-
- /* Forcing a free */
- mutex->usage = 1;
- nfp_cpp_mutex_free(mutex);
- }
/* Remove all caches */
list_for_each_entry_safe(cache, ctmp, &cpp->area_cache_list, entry) {
@@ -1127,7 +1106,6 @@ nfp_cpp_from_operations(const struct nfp_cpp_operations
*ops,
rwlock_init(&cpp->resource_lock);
init_waitqueue_head(&cpp->waitq);
lockdep_set_class(&cpp->resource_lock, &nfp_cpp_resource_lock_key);
- INIT_LIST_HEAD(&cpp->mutex_cache);
INIT_LIST_HEAD(&cpp->resource_list);
INIT_LIST_HEAD(&cpp->area_cache_list);
mutex_init(&cpp->area_cache_mutex);
@@ -1536,14 +1514,6 @@ struct nfp_cpp_mutex *nfp_cpp_mutex_alloc(struct nfp_cpp
*cpp, int target,
if (err)
return NULL;
- /* Look for mutex on cache list */
- list_for_each_entry(mutex, &cpp->mutex_cache, list) {
- if (mutex->target == target && mutex->address == address) {
- mutex->usage++;
- return mutex;
- }
- }
-
err = nfp_cpp_readl(cpp, mur, address + 4, &tmp);
if (err < 0)
return NULL;
@@ -1560,10 +1530,6 @@ struct nfp_cpp_mutex *nfp_cpp_mutex_alloc(struct nfp_cpp
*cpp, int target,
mutex->address = address;
mutex->key = key;
mutex->depth = 0;
- mutex->usage = 1;
-
- /* Add mutex to cache list */
- list_add(&mutex->list, &cpp->mutex_cache);
return mutex;
}
@@ -1574,11 +1540,6 @@ struct nfp_cpp_mutex *nfp_cpp_mutex_alloc(struct nfp_cpp
*cpp, int target,
*/
void nfp_cpp_mutex_free(struct nfp_cpp_mutex *mutex)
{
- if (--mutex->usage)
- return;
-
- /* Remove mutex from cache */
- list_del(&mutex->list);
kfree(mutex);
}
@@ -1611,8 +1572,8 @@ int nfp_cpp_mutex_lock(struct nfp_cpp_mutex *mutex)
if (time_is_before_eq_jiffies(warn_at)) {
warn_at = jiffies + 60 * HZ;
dev_warn(mutex->cpp->dev.parent,
- "Warning: waiting for NFP mutex [usage:%hd
depth:%hd target:%d addr:%llx key:%08x]\n",
- mutex->usage, mutex->depth,
+ "Warning: waiting for NFP mutex [depth:%hd
target:%d addr:%llx key:%08x]\n",
+ mutex->depth,
mutex->target, mutex->address, mutex->key);
}
}
--
2.11.0
