[PATCH libdrm 2/3] amdgpu: add a function to find bo by cpu mapping (v2)

[Junwei Zhang]

Userspace needs to know if the user memory is from BO or malloc.

v2: update mutex range and rebase

Signed-off-by: Junwei Zhang <Jerry.Zhang at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>
---
 amdgpu/amdgpu.h    | 23 +++++++++++++++++++++++
 amdgpu/amdgpu_bo.c | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/amdgpu/amdgpu.h b/amdgpu/amdgpu.h
index be83b45..a8c353c 100644
--- a/amdgpu/amdgpu.h
+++ b/amdgpu/amdgpu.h
@@ -678,6 +678,29 @@ int amdgpu_create_bo_from_user_mem(amdgpu_device_handle dev,
 				    amdgpu_bo_handle *buf_handle);
 
 /**
+ * Validate if the user memory comes from BO
+ *
+ * \param dev - [in] Device handle. See #amdgpu_device_initialize()
+ * \param cpu - [in] CPU address of user allocated memory which we
+ * want to map to GPU address space (make GPU accessible)
+ * (This address must be correctly aligned).
+ * \param size - [in] Size of allocation (must be correctly aligned)
+ * \param buf_handle - [out] Buffer handle for the userptr memory
+ * if the user memory is not from BO, the buf_handle will be NULL.
+ * \param offset_in_bo - [out] offset in this BO for this user memory
+ *
+ *
+ * \return   0 on success\n
+ *          <0 - Negative POSIX Error code
+ *
+*/
+int amdgpu_find_bo_by_cpu_mapping(amdgpu_device_handle dev,
+				  void *cpu,
+				  uint64_t size,
+				  amdgpu_bo_handle *buf_handle,
+				  uint64_t *offset_in_bo);
+
+/**
  * Free previosuly allocated memory
  *
  * \param   dev	       - \c [in] Device handle. See #amdgpu_device_initialize()
diff --git a/amdgpu/amdgpu_bo.c b/amdgpu/amdgpu_bo.c
index b24e698..b790e9b 100644
--- a/amdgpu/amdgpu_bo.c
+++ b/amdgpu/amdgpu_bo.c
@@ -529,6 +529,45 @@ int amdgpu_bo_wait_for_idle(amdgpu_bo_handle bo,
 	}
 }
 
+int amdgpu_find_bo_by_cpu_mapping(amdgpu_device_handle dev,
+				  void *cpu,
+				  uint64_t size,
+				  amdgpu_bo_handle *buf_handle,
+				  uint64_t *offset_in_bo)
+{
+	int i;
+	struct amdgpu_bo *bo;
+
+	if (cpu == NULL || size == 0)
+		return -EINVAL;
+
+	/*
+	 * Workaround for a buggy application which tries to import previously
+	 * exposed CPU pointers. If we find a real world use case we should
+	 * improve that by asking the kernel for the right handle.
+	 */
+	pthread_mutex_lock(&dev->bo_table_mutex);
+	for (i = 0; i < dev->bo_handles.max_key; i++) {
+		bo = handle_table_lookup(&dev->bo_handles, i);
+		if (!bo || !bo->cpu_ptr || size > bo->alloc_size)
+			continue;
+		if (cpu >= bo->cpu_ptr && cpu < (bo->cpu_ptr + bo->alloc_size))
+			break;
+	}
+
+	if (i < dev->bo_handles.max_key) {
+		atomic_inc(&bo->refcount);
+		*buf_handle = bo;
+		*offset_in_bo = cpu - bo->cpu_ptr;
+	} else {
+		*buf_handle = NULL;
+		*offset_in_bo = 0;
+	}
+	pthread_mutex_unlock(&dev->bo_table_mutex);
+
+	return 0;
+}
+
 int amdgpu_create_bo_from_user_mem(amdgpu_device_handle dev,
 				    void *cpu,
 				    uint64_t size,
-- 
1.9.1