dma-buf/fence: make fence context 64 bit v2

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>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1464786612-5010-2-git-send-email-deathsimple@vodafone.de

diff --git a/drivers/dma-buf/fence.c b/drivers/dma-buf/fence.c
index 7b05dbe..4d51f9e 100644 (file)
--- 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 (file)
--- 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/amd/amdgpu/amdgpu_sa.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c
index 8bf84ef..b16366c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c
@@ -427,7 +427,7 @@ 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 f5321e2..a69cdd5 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 b56885c..ebb34dc 100644 (file)
--- 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..18a97c6 100644 (file)
--- 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);
@@ -352,27 +353,27 @@ 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)