Commit 497d7cee authored by Alex Deucher's avatar Alex Deucher
Browse files

drm/amdgpu: add a spinlock to wb allocation 



As we use wb slots more dynamically, we need to lock
access to avoid racing on allocation or free.

Reviewed-by: default avatarShaoyun.liu <shaoyunl@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 754c366e

drivers/gpu/drm/amd/amdgpu/amdgpu.h

+1 −0
Original line number Diff line number Diff line
@@ -502,6 +502,7 @@ struct amdgpu_wb { 
	uint64_t		gpu_addr;

	u32			num_wb;	/* Number of wb slots actually reserved for amdgpu. */

	unsigned long		used[DIV_ROUND_UP(AMDGPU_MAX_WB, BITS_PER_LONG)];

	spinlock_t		lock;

};



int amdgpu_device_wb_get(struct amdgpu_device *adev, u32 *wb);

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

+10 −1
Original line number Diff line number Diff line
@@ -1482,13 +1482,17 @@ static int amdgpu_device_wb_init(struct amdgpu_device *adev) 
 */

int amdgpu_device_wb_get(struct amdgpu_device *adev, u32 *wb)

{

	unsigned long offset = find_first_zero_bit(adev->wb.used, adev->wb.num_wb);

	unsigned long flags, offset;



	spin_lock_irqsave(&adev->wb.lock, flags);

	offset = find_first_zero_bit(adev->wb.used, adev->wb.num_wb);

	if (offset < adev->wb.num_wb) {

		__set_bit(offset, adev->wb.used);

		spin_unlock_irqrestore(&adev->wb.lock, flags);

		*wb = offset << 3; /* convert to dw offset */

		return 0;

	} else {

		spin_unlock_irqrestore(&adev->wb.lock, flags);

		return -EINVAL;

	}

}
@@ -1503,9 +1507,13 @@ int amdgpu_device_wb_get(struct amdgpu_device *adev, u32 *wb) 
 */

void amdgpu_device_wb_free(struct amdgpu_device *adev, u32 wb)

{

	unsigned long flags;



	wb >>= 3;

	spin_lock_irqsave(&adev->wb.lock, flags);

	if (wb < adev->wb.num_wb)

		__clear_bit(wb, adev->wb.used);

	spin_unlock_irqrestore(&adev->wb.lock, flags);

}



/**
@@ -4061,6 +4069,7 @@ int amdgpu_device_init(struct amdgpu_device *adev, 
	spin_lock_init(&adev->se_cac_idx_lock);

	spin_lock_init(&adev->audio_endpt_idx_lock);

	spin_lock_init(&adev->mm_stats.lock);

	spin_lock_init(&adev->wb.lock);



	INIT_LIST_HEAD(&adev->shadow_list);

	mutex_init(&adev->shadow_list_lock);