From: Christian König <christian.koe...@amd.com>
Fence contexts are created on the fly (for example) by the GPU scheduler used
in the amdgpu driver as a result of an userspace request. Because of this
userspace could in theory force a wrap around of the 32bit context number
if it doesn't behave well.
Avoid this by increasing the context number to 64bits. This way even when
userspace manages to allocate a billion contexts per second it takes more
than 500 years for the context number to wrap around.
Signed-off-by: Christian König <christian.koenig at amd.com>
---
drivers/dma-buf/fence.c | 8 ++++----
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +-
drivers/gpu/drm/etnaviv/etnaviv_gpu.h | 2 +-
drivers/gpu/drm/nouveau/nouveau_fence.h | 3 ++-
drivers/gpu/drm/radeon/radeon.h | 2 +-
drivers/gpu/drm/vmwgfx/vmwgfx_fence.c | 2 +-
drivers/staging/android/sync.h | 3 ++-
include/linux/fence.h | 7 ++++---
8 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/dma-buf/fence.c b/drivers/dma-buf/fence.c
index 7b05dbe..4d51f9e 100644
--- a/drivers/dma-buf/fence.c
+++ b/drivers/dma-buf/fence.c
@@ -35,7 +35,7 @@ EXPORT_TRACEPOINT_SYMBOL(fence_emit);
* context or not. One device can have multiple separate contexts,
* and they're used if some engine can run independently of another.
*/
-static atomic_t fence_context_counter = ATOMIC_INIT(0);
+static atomic64_t fence_context_counter = ATOMIC64_INIT(0);
/**
* fence_context_alloc - allocate an array of fence contexts
@@ -44,10 +44,10 @@ static atomic_t fence_context_counter = ATOMIC_INIT(0);
* This function will return the first index of the number of fences allocated.
* The fence context is used for setting fence->context to a unique number.
*/
-unsigned fence_context_alloc(unsigned num)
+u64 fence_context_alloc(unsigned num)
{
BUG_ON(!num);
- return atomic_add_return(num, &fence_context_counter) - num;
+ return atomic64_add_return(num, &fence_context_counter) - num;
}
EXPORT_SYMBOL(fence_context_alloc);
@@ -513,7 +513,7 @@ EXPORT_SYMBOL(fence_wait_any_timeout);
*/
void
fence_init(struct fence *fence, const struct fence_ops *ops,
- spinlock_t *lock, unsigned context, unsigned seqno)
+ spinlock_t *lock, u64 context, unsigned seqno)
{
BUG_ON(!lock);
BUG_ON(!ops || !ops->wait || !ops->enable_signaling ||
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 992f00b..da3d021 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -2032,7 +2032,7 @@ struct amdgpu_device {
struct amdgpu_irq_src hpd_irq;
/* rings */
- unsigned fence_context;
+ u64 fence_context;
unsigned num_rings;
struct amdgpu_ring *rings[AMDGPU_MAX_RINGS];
bool ib_pool_ready;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index f5321e2..a69cdd5 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -125,7 +125,7 @@ struct etnaviv_gpu {
u32 completed_fence;
u32 retired_fence;
wait_queue_head_t fence_event;
- unsigned int fence_context;
+ u64 fence_context;
spinlock_t fence_spinlock;
/* worker for handling active-list retiring: */
diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.h
b/drivers/gpu/drm/nouveau/nouveau_fence.h
index 2e3a62d..64c4ce7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.h
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.h
@@ -57,7 +57,8 @@ struct nouveau_fence_priv {
int (*context_new)(struct nouveau_channel *);
void (*context_del)(struct nouveau_channel *);
- u32 contexts, context_base;
+ u32 contexts;
+ u64 context_base;
bool uevent;
};
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 80b24a4..5633ee3 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2386,7 +2386,7 @@ struct radeon_device {
struct radeon_mman mman;
struct radeon_fence_driver fence_drv[RADEON_NUM_RINGS];
wait_queue_head_t fence_queue;
- unsigned fence_context;
+ u64 fence_context;
struct mutex ring_lock;
struct radeon_ring ring[RADEON_NUM_RINGS];
bool ib_pool_ready;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
index e959df6..26ac8e8 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
@@ -46,7 +46,7 @@ struct vmw_fence_manager {
bool goal_irq_on; /* Protected by @goal_irq_mutex */
bool seqno_valid; /* Protected by @lock, and may not be set to true
without the @goal_irq_mutex held. */
- unsigned ctx;
+ u64 ctx;
};
struct vmw_user_fence {
diff --git a/drivers/staging/android/sync.h b/drivers/staging/android/sync.h
index d2a1734..ef1f7d4 100644
--- a/drivers/staging/android/sync.h
+++ b/drivers/staging/android/sync.h
@@ -68,7 +68,8 @@ struct sync_timeline {
/* protected by child_list_lock */
bool destroyed;
- int context, value;
+ u64 context;
+ int value;
struct list_head child_list_head;
spinlock_t child_list_lock;
diff --git a/include/linux/fence.h b/include/linux/fence.h
index 2b17698..350caaa 100644
--- a/include/linux/fence.h
+++ b/include/linux/fence.h
@@ -75,7 +75,8 @@ struct fence {
struct rcu_head rcu;
struct list_head cb_list;
spinlock_t *lock;
- unsigned context, seqno;
+ u64 context;
+ unsigned seqno;
unsigned long flags;
ktime_t timestamp;
int status;
@@ -178,7 +179,7 @@ struct fence_ops {
};
void fence_init(struct fence *fence, const struct fence_ops *ops,
- spinlock_t *lock, unsigned context, unsigned seqno);
+ spinlock_t *lock, u64 context, unsigned seqno);
void fence_release(struct kref *kref);
void fence_free(struct fence *fence);
@@ -352,7 +353,7 @@ static inline signed long fence_wait(struct fence *fence,
bool intr)
return ret < 0 ? ret : 0;
}
-unsigned fence_context_alloc(unsigned num);
+u64 fence_context_alloc(unsigned num);
#define FENCE_TRACE(f, fmt, args...) \
do { \
--
2.5.0
