drm/nouveau: add spinlock around ramht modifications

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_ramht.c b/drivers/gpu/drm/nouveau/nouveau_ramht.c
index ccbc8d69ea686760cf7af3c5e9022cc176c9d51c..de34b6bb059f5789cdcf2fd83a3dcac1506bb664 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_ramht.c
+++ b/drivers/gpu/drm/nouveau/nouveau_ramht.c
@@ -27,13 +27,13 @@
 #include "nouveau_drv.h"
 #include "nouveau_ramht.h"
 
-static uint32_t
-nouveau_ramht_hash_handle(struct nouveau_channel *chan, uint32_t handle)
+static u32
+nouveau_ramht_hash_handle(struct nouveau_channel *chan, u32 handle)
 {
        struct drm_device *dev = chan->dev;
        struct drm_nouveau_private *dev_priv = dev->dev_private;
        struct nouveau_ramht *ramht = chan->ramht;
-       uint32_t hash = 0;
+       u32 hash = 0;
        int i;
 
        NV_DEBUG(dev, "ch%d handle=0x%08x\n", chan->id, handle);
@@ -53,10 +53,10 @@ nouveau_ramht_hash_handle(struct nouveau_channel *chan, uint32_t handle)
 
 static int
 nouveau_ramht_entry_valid(struct drm_device *dev, struct nouveau_gpuobj *ramht,
-                         uint32_t offset)
+                         u32 offset)
 {
        struct drm_nouveau_private *dev_priv = dev->dev_private;
-       uint32_t ctx = nv_ro32(ramht, offset + 4);
+       u32 ctx = nv_ro32(ramht, offset + 4);
 
        if (dev_priv->card_type < NV_40)
                return ((ctx & NV_RAMHT_CONTEXT_VALID) != 0);
@@ -72,7 +72,8 @@ nouveau_ramht_insert(struct nouveau_channel *chan, u32 handle,
        struct nouveau_instmem_engine *instmem = &dev_priv->engine.instmem;
        struct nouveau_ramht_entry *entry;
        struct nouveau_gpuobj *ramht = chan->ramht->gpuobj;
-       uint32_t ctx, co, ho;
+       unsigned long flags;
+       u32 ctx, co, ho;
 
        if (nouveau_ramht_find(chan, handle))
                return -EEXIST;
@@ -83,7 +84,6 @@ nouveau_ramht_insert(struct nouveau_channel *chan, u32 handle,
        entry->channel = chan;
        entry->gpuobj = NULL;
        entry->handle = handle;
-       list_add(&entry->head, &chan->ramht->entries);
        nouveau_gpuobj_ref(gpuobj, &entry->gpuobj);
 
        if (dev_priv->card_type < NV_40) {
@@ -105,6 +105,9 @@ nouveau_ramht_insert(struct nouveau_channel *chan, u32 handle,
                }
        }
 
+       spin_lock_irqsave(&chan->ramht->lock, flags);
+       list_add(&entry->head, &chan->ramht->entries);
+
        co = ho = nouveau_ramht_hash_handle(chan, handle);
        do {
                if (!nouveau_ramht_entry_valid(dev, ramht, co)) {
@@ -114,6 +117,7 @@ nouveau_ramht_insert(struct nouveau_channel *chan, u32 handle,
                        nv_wo32(ramht, co + 0, handle);
                        nv_wo32(ramht, co + 4, ctx);
 
+                       spin_unlock_irqrestore(&chan->ramht->lock, flags);
                        instmem->flush(dev);
                        return 0;
                }
@@ -127,12 +131,13 @@ nouveau_ramht_insert(struct nouveau_channel *chan, u32 handle,
 
        NV_ERROR(dev, "RAMHT space exhausted. ch=%d\n", chan->id);
        list_del(&entry->head);
+       spin_unlock_irqrestore(&chan->ramht->lock, flags);
        kfree(entry);
        return -ENOMEM;
 }
 
-void
-nouveau_ramht_remove(struct nouveau_channel *chan, u32 handle)
+static void
+nouveau_ramht_remove_locked(struct nouveau_channel *chan, u32 handle)
 {
        struct drm_device *dev = chan->dev;
        struct drm_nouveau_private *dev_priv = dev->dev_private;
@@ -173,17 +178,35 @@ nouveau_ramht_remove(struct nouveau_channel *chan, u32 handle)
                 chan->id, handle);
 }
 
+void
+nouveau_ramht_remove(struct nouveau_channel *chan, u32 handle)
+{
+       struct nouveau_ramht *ramht = chan->ramht;
+       unsigned long flags;
+
+       spin_lock_irqsave(&ramht->lock, flags);
+       nouveau_ramht_remove_locked(chan, handle);
+       spin_unlock_irqrestore(&ramht->lock, flags);
+}
+
 struct nouveau_gpuobj *
 nouveau_ramht_find(struct nouveau_channel *chan, u32 handle)
 {
+       struct nouveau_ramht *ramht = chan->ramht;
        struct nouveau_ramht_entry *entry;
+       struct nouveau_gpuobj *gpuobj = NULL;
+       unsigned long flags;
 
+       spin_lock_irqsave(&ramht->lock, flags);
        list_for_each_entry(entry, &chan->ramht->entries, head) {
-               if (entry->channel == chan && entry->handle == handle)
-                       return entry->gpuobj;
+               if (entry->channel == chan && entry->handle == handle) {
+                       gpuobj = entry->gpuobj;
+                       break;
+               }
        }
+       spin_unlock_irqrestore(&ramht->lock, flags);
 
-       return NULL;
+       return gpuobj;
 }
 
 int
@@ -197,36 +220,49 @@ nouveau_ramht_new(struct drm_device *dev, struct nouveau_gpuobj *gpuobj,
                return -ENOMEM;
 
        ramht->dev = dev;
-       ramht->refcount = 1;
+       kref_init(&ramht->refcount);
        ramht->bits = drm_order(gpuobj->size / 8);
        INIT_LIST_HEAD(&ramht->entries);
+       spin_lock_init(&ramht->lock);
        nouveau_gpuobj_ref(gpuobj, &ramht->gpuobj);
 
        *pramht = ramht;
        return 0;
 }
 
+static void
+nouveau_ramht_del(struct kref *ref)
+{
+       struct nouveau_ramht *ramht =
+               container_of(ref, struct nouveau_ramht, refcount);
+
+       nouveau_gpuobj_ref(NULL, &ramht->gpuobj);
+       kfree(ramht);
+}
+
 void
 nouveau_ramht_ref(struct nouveau_ramht *ref, struct nouveau_ramht **ptr,
                  struct nouveau_channel *chan)
 {
        struct nouveau_ramht_entry *entry, *tmp;
        struct nouveau_ramht *ramht;
+       unsigned long flags;
 
        if (ref)
-               ref->refcount++;
+               kref_get(&ref->refcount);
 
        ramht = *ptr;
        if (ramht) {
+               spin_lock_irqsave(&ramht->lock, flags);
                list_for_each_entry_safe(entry, tmp, &ramht->entries, head) {
-                       if (entry->channel == chan)
-                               nouveau_ramht_remove(chan, entry->handle);
-               }
+                       if (entry->channel != chan)
+                               continue;
 
-               if (--ramht->refcount == 0) {
-                       nouveau_gpuobj_ref(NULL, &ramht->gpuobj);
-                       kfree(ramht);
+                       nouveau_ramht_remove_locked(chan, entry->handle);
                }
+               spin_unlock_irqrestore(&ramht->lock, flags);
+
+               kref_put(&ramht->refcount, nouveau_ramht_del);
        }
        *ptr = ref;
 }

diff --git a/drivers/gpu/drm/nouveau/nouveau_ramht.h b/drivers/gpu/drm/nouveau/nouveau_ramht.h
index f37737a93642626de66caa65b880f9224ec01d1c..b79cb5e1a8f1cc8f4404eeea4e37fb4fe0e19d7e 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_ramht.h
+++ b/drivers/gpu/drm/nouveau/nouveau_ramht.h
@@ -34,7 +34,8 @@ struct nouveau_ramht_entry {
 
 struct nouveau_ramht {
        struct drm_device *dev;
-       int refcount;
+       struct kref refcount;
+       spinlock_t lock;
        struct nouveau_gpuobj *gpuobj;
        struct list_head entries;
        int bits;