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author | Thomas Hellstrom <thellstrom@vmware.com> | 2012-11-20 13:16:47 +0100 |
---|---|---|
committer | Dave Airlie <airlied@redhat.com> | 2012-11-28 09:36:05 +0100 |
commit | 384cc2f9688994dfd505011ba3b08e0a702030b0 (patch) | |
tree | 9d7f8d1f3a68d88442d35cd13a67563571147f29 /drivers/gpu/drm/drm_hashtab.c | |
parent | drm/vmwgfx: Add and make use of a header for surface size calculation. (diff) | |
download | linux-384cc2f9688994dfd505011ba3b08e0a702030b0.tar.xz linux-384cc2f9688994dfd505011ba3b08e0a702030b0.zip |
drm: Add a hash-tab rcu-safe API
While hashtab should now be RCU-safe, Add a drm_ht_xxx_api for consumers
to use to make it obvious what locking mechanism is used.
Document the way the rcu-safe interface should be used.
Don't use rcu-safe list traversal in modify operations where we should use
a spinlock / mutex anyway.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/drm_hashtab.c')
-rw-r--r-- | drivers/gpu/drm/drm_hashtab.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c index 5729e390aa4e..80254547a3f8 100644 --- a/drivers/gpu/drm/drm_hashtab.c +++ b/drivers/gpu/drm/drm_hashtab.c @@ -67,7 +67,7 @@ void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key) hashed_key = hash_long(key, ht->order); DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key); h_list = &ht->table[hashed_key]; - hlist_for_each_entry_rcu(entry, list, h_list, head) + hlist_for_each_entry(entry, list, h_list, head) DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key); } @@ -81,7 +81,7 @@ static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht, hashed_key = hash_long(key, ht->order); h_list = &ht->table[hashed_key]; - hlist_for_each_entry_rcu(entry, list, h_list, head) { + hlist_for_each_entry(entry, list, h_list, head) { if (entry->key == key) return list; if (entry->key > key) @@ -90,6 +90,24 @@ static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht, return NULL; } +static struct hlist_node *drm_ht_find_key_rcu(struct drm_open_hash *ht, + unsigned long key) +{ + struct drm_hash_item *entry; + struct hlist_head *h_list; + struct hlist_node *list; + unsigned int hashed_key; + + hashed_key = hash_long(key, ht->order); + h_list = &ht->table[hashed_key]; + hlist_for_each_entry_rcu(entry, list, h_list, head) { + if (entry->key == key) + return list; + if (entry->key > key) + break; + } + return NULL; +} int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) { @@ -102,7 +120,7 @@ int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item) hashed_key = hash_long(key, ht->order); h_list = &ht->table[hashed_key]; parent = NULL; - hlist_for_each_entry_rcu(entry, list, h_list, head) { + hlist_for_each_entry(entry, list, h_list, head) { if (entry->key == key) return -EINVAL; if (entry->key > key) @@ -152,7 +170,7 @@ int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, { struct hlist_node *list; - list = drm_ht_find_key(ht, key); + list = drm_ht_find_key_rcu(ht, key); if (!list) return -EINVAL; |