From: Christian König christian.koenig@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.
v2: fix printf formats as well.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/fence.c | 8 ++++---- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_gpu.h | 2 +- drivers/gpu/drm/nouveau/nouveau_fence.h | 3 ++- drivers/gpu/drm/qxl/qxl_release.c | 2 +- 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 | 13 +++++++------ 10 files changed, 21 insertions(+), 18 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 3d0cec2..7d25977 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -2045,7 +2045,7 @@ 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/amd/amdgpu/amdgpu_sa.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c index 48618ee..d8af37a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c @@ -428,7 +428,7 @@ void amdgpu_sa_bo_dump_debug_info(struct amdgpu_sa_manager *sa_manager, soffset, eoffset, eoffset - soffset);
if (i->fence) - seq_printf(m, " protected by 0x%08x on context %d", + seq_printf(m, " protected by 0x%08x on context %llu", i->fence->seqno, i->fence->context);
seq_printf(m, "\n"); diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h index f233ac4..6a69214 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h @@ -123,7 +123,7 @@ 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/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c index 4efa8e2..f599cd0 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -96,7 +96,7 @@ retry: return 0;
if (have_drawable_releases && sc > 300) { - FENCE_WARN(fence, "failed to wait on release %d " + FENCE_WARN(fence, "failed to wait on release %llu " "after spincount %d\n", fence->context & ~0xf0000000, sc); goto signaled; 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 8e689b4..96308e3 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 afa0752..9298677 100644 --- a/drivers/staging/android/sync.h +++ b/drivers/staging/android/sync.h @@ -96,7 +96,8 @@ 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 5aa95eb..a2c4f53 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; @@ -176,7 +177,7 @@ 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); @@ -350,27 +351,27 @@ 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 { \ struct fence *__ff = (f); \ if (config_enabled(CONFIG_FENCE_TRACE)) \ - pr_info("f %u#%u: " fmt, \ + pr_info("f %llu#%u: " fmt, \ __ff->context, __ff->seqno, ##args); \ } while (0)
#define FENCE_WARN(f, fmt, args...) \ do { \ struct fence *__ff = (f); \ - pr_warn("f %u#%u: " fmt, __ff->context, __ff->seqno, \ + pr_warn("f %llu#%u: " fmt, __ff->context, __ff->seqno, \ ##args); \ } while (0)
#define FENCE_ERR(f, fmt, args...) \ do { \ struct fence *__ff = (f); \ - pr_err("f %u#%u: " fmt, __ff->context, __ff->seqno, \ + pr_err("f %llu#%u: " fmt, __ff->context, __ff->seqno, \ ##args); \ } while (0)