[PATCH libdrm 7/9] amdgpu: Use normal integers for device / core BO reference counting

[Michel Dänzer]

From: Michel Dänzer <michel.daen...@amd.com>

The dev_mutex / dev->bo_table_mutex is always locked when accessing the
reference counts, so no need for atomic operations.

Signed-off-by: Michel Dänzer <michel.daen...@amd.com>
---
 amdgpu/amdgpu_bo.c       |  6 +++---
 amdgpu/amdgpu_device.c   | 18 ++++++++++--------
 amdgpu/amdgpu_internal.h |  6 +++---
 3 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/amdgpu/amdgpu_bo.c b/amdgpu/amdgpu_bo.c
index 8d42db90..f40df484 100644
--- a/amdgpu/amdgpu_bo.c
+++ b/amdgpu/amdgpu_bo.c
@@ -65,7 +65,7 @@ static int amdgpu_core_bo_create(struct amdgpu_core_device 
*dev,
                return r;
        }
 
-       atomic_set(&bo->refcount, 1);
+       bo->refcount = 1;
        bo->alloc_size = size;
        bo->handle = handle;
        pthread_mutex_init(&bo->cpu_access_mutex, NULL);
@@ -95,7 +95,7 @@ static int amdgpu_bo_create(amdgpu_device_handle user_dev,
                                goto out;
                        }
                }
-               atomic_inc(&bo->refcount);
+               bo->refcount++;
        } else {
                r = amdgpu_core_bo_create(dev, size, handle, &bo);
                if (r)
@@ -467,7 +467,7 @@ static void amdgpu_core_bo_free(struct amdgpu_bo *user_bo)
        struct amdgpu_core_device *dev = user_bo->dev->core;
        struct amdgpu_core_bo *bo = user_bo->core;
 
-       if (update_references(&bo->refcount, NULL)) {
+       if (--bo->refcount == 0) {
                /* Remove the buffer from the hash tables. */
                handle_table_remove(&dev->bo_handles, bo->handle);
 
diff --git a/amdgpu/amdgpu_device.c b/amdgpu/amdgpu_device.c
index 8d9a85c2..8a99b8bb 100644
--- a/amdgpu/amdgpu_device.c
+++ b/amdgpu/amdgpu_device.c
@@ -72,6 +72,9 @@ static int fd_compare(int fd1, int fd2)
 
 static void amdgpu_device_free(struct amdgpu_core_device *dev)
 {
+       if (--dev->refcount > 0)
+               return;
+
        close(dev->fd);
 
        amdgpu_vamgr_deinit(&dev->vamgr_32);
@@ -112,7 +115,7 @@ static int amdgpu_device_init(amdgpu_device_handle user_dev)
                        break;
 
        if (dev_iter) {
-               atomic_inc(&dev_iter->core->refcount);
+               dev_iter->core->refcount++;
                user_dev->core = dev_iter->core;
                return 0;
        }
@@ -123,7 +126,7 @@ static int amdgpu_device_init(amdgpu_device_handle user_dev)
                return -ENOMEM;
        }
 
-       atomic_set(&dev->refcount, 1);
+       dev->refcount = 1;
        pthread_mutex_init(&dev->bo_table_mutex, NULL);
 
        dev->fd = user_dev->user_fd;
@@ -199,7 +202,7 @@ drm_public int amdgpu_device_initialize(int fd,
 
        for (user_dev = dev_list; user_dev; user_dev = user_dev->next) {
                if (same_file_description(user_dev->user_fd, fd)) {
-                       atomic_inc(&user_dev->refcount);
+                       user_dev->refcount++;
                        goto out;
                }
        }
@@ -233,7 +236,7 @@ drm_public int amdgpu_device_initialize(int fd,
                goto cleanup;
        }
 
-       atomic_set(&user_dev->refcount, 1);
+       user_dev->refcount = 1;
        user_dev->next = dev_list;
        dev_list = user_dev;
 
@@ -248,7 +251,7 @@ out:
 cleanup:
        if (!user_dev->core || user_dev->user_fd != user_dev->core->fd)
                close(user_dev->user_fd);
-       if (user_dev->core && update_references(&user_dev->core->refcount, 
NULL))
+       if (user_dev->core)
                amdgpu_device_free(user_dev->core);
        free(user_dev);
        pthread_mutex_unlock(&dev_mutex);
@@ -261,7 +264,7 @@ drm_public int 
amdgpu_device_deinitialize(amdgpu_device_handle user_dev)
 
        pthread_mutex_lock(&dev_mutex);
 
-       if (update_references(&user_dev->refcount, NULL)) {
+       if (--user_dev->refcount == 0) {
                struct amdgpu_device **node = &dev_list;
 
                while (*node != user_dev && (*node)->next)
@@ -271,8 +274,7 @@ drm_public int 
amdgpu_device_deinitialize(amdgpu_device_handle user_dev)
                if (user_dev->user_fd != dev->fd)
                        close(user_dev->user_fd);
 
-               if (update_references(&dev->refcount, NULL))
-                       amdgpu_device_free(dev);
+               amdgpu_device_free(dev);
 
                free(user_dev);
        }
diff --git a/amdgpu/amdgpu_internal.h b/amdgpu/amdgpu_internal.h
index 686d50ec..70566f98 100644
--- a/amdgpu/amdgpu_internal.h
+++ b/amdgpu/amdgpu_internal.h
@@ -65,7 +65,7 @@ struct amdgpu_va {
 };
 
 struct amdgpu_core_device {
-       atomic_t refcount;
+       int refcount;
        int fd;
        unsigned major_version;
        unsigned minor_version;
@@ -90,14 +90,14 @@ struct amdgpu_core_device {
 };
 
 struct amdgpu_device {
-       atomic_t refcount;
+       int refcount;
        int user_fd;
        struct amdgpu_core_device *core;
        struct amdgpu_device *next;
 };
 
 struct amdgpu_core_bo {
-       atomic_t refcount;
+       int refcount;
        amdgpu_bo_handle user_bos;
 
        uint64_t alloc_size;
-- 
2.20.1

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