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Commit 98515461 authored by Depeng Shao's avatar Depeng Shao Committed by Pritam Sarkar
Browse files

msm: camera: memmgr: Remove the mutex lock for kref variable 



kref operation is atmoic operation, so no need to use mutex
to protect it, and the cam_mem_put_cpu_buf is also called
in spinlock context, so we can't use mutex lock in this
function. This change removes the mutex lock for kref
variable protextion.

CRs-Fixed: 3786887
Change-Id: Ic05bdafacf06cde6a8d8dbae7512e5d22eb7f514
Signed-off-by: default avatarDepeng Shao <quic_depengs@quicinc.com>
parent 6b4232c9

drivers/cam_req_mgr/cam_mem_mgr.c

+4 −25
Original line number Diff line number Diff line
@@ -188,7 +188,6 @@ static int32_t cam_mem_get_slot(void) 
		set_bit(idx, tbl.bitmap);

		tbl.bufq[idx].active = true;

		mutex_init(&tbl.bufq[idx].q_lock);

		mutex_init(&tbl.bufq[idx].ref_lock);

		mutex_unlock(&tbl.m_lock);

		return idx;

	}
@@ -202,13 +201,10 @@ static void cam_mem_put_slot(int32_t idx) 
	mutex_lock(&tbl.m_lock);

	mutex_lock(&tbl.bufq[idx].q_lock);

	tbl.bufq[idx].active = false;

	kref_init(&tbl.bufq[idx].krefcount);

	kref_init(&tbl.bufq[idx].urefcount);

	mutex_unlock(&tbl.bufq[idx].q_lock);

	mutex_lock(&tbl.bufq[idx].ref_lock);

	memset(&tbl.bufq[idx].krefcount, 0, sizeof(struct kref));

	memset(&tbl.bufq[idx].urefcount, 0, sizeof(struct kref));

	mutex_unlock(&tbl.bufq[idx].ref_lock);

	mutex_destroy(&tbl.bufq[idx].q_lock);

	mutex_destroy(&tbl.bufq[idx].ref_lock);

	clear_bit(idx, tbl.bitmap);

	mutex_unlock(&tbl.m_lock);

}
@@ -301,18 +297,15 @@ int cam_mem_get_cpu_buf(int32_t buf_handle, uintptr_t *vaddr_ptr, size_t *len) 
		return -EINVAL;

	}



	mutex_lock(&tbl.bufq[idx].ref_lock);

	if (tbl.bufq[idx].kmdvaddr && kref_get_unless_zero(&tbl.bufq[idx].krefcount)) {

		*vaddr_ptr = tbl.bufq[idx].kmdvaddr;

		*len = tbl.bufq[idx].len;

	} else {

		mutex_unlock(&tbl.bufq[idx].ref_lock);

		CAM_ERR(CAM_MEM,

			"No KMD access request, vaddr= %p, idx= %d, handle= %d",

			tbl.bufq[idx].kmdvaddr, idx, buf_handle);

		return -EINVAL;

	}

	mutex_unlock(&tbl.bufq[idx].ref_lock);



	return 0;

}
@@ -971,13 +964,10 @@ static int cam_mem_mgr_cleanup_table(void) 
		tbl.bufq[i].num_hdl = 0;

		tbl.bufq[i].dma_buf = NULL;

		tbl.bufq[i].active = false;

		kref_init(&tbl.bufq[i].krefcount);

		kref_init(&tbl.bufq[i].urefcount);

		mutex_unlock(&tbl.bufq[i].q_lock);

		mutex_lock(&tbl.bufq[i].ref_lock);

		memset(&tbl.bufq[i].krefcount, 0, sizeof(struct kref));

		memset(&tbl.bufq[i].urefcount, 0, sizeof(struct kref));

		mutex_unlock(&tbl.bufq[i].ref_lock);

		mutex_destroy(&tbl.bufq[i].q_lock);

		mutex_destroy(&tbl.bufq[i].ref_lock);

	}



	bitmap_zero(tbl.bitmap, tbl.bits);
@@ -1103,7 +1093,6 @@ static void cam_mem_util_unmap_wrapper(struct kref *kref) 


	cam_mem_util_unmap(idx);



	mutex_destroy(&tbl.bufq[idx].ref_lock);

}



void cam_mem_put_cpu_buf(int32_t buf_handle)
@@ -1137,7 +1126,6 @@ void cam_mem_put_cpu_buf(int32_t buf_handle) 
		return;

	}



	mutex_lock(&tbl.bufq[idx].ref_lock);

	kref_put(&tbl.bufq[idx].krefcount, cam_mem_util_unmap_dummy);



	krefcount = kref_read(&tbl.bufq[idx].krefcount);
@@ -1155,10 +1143,7 @@ void cam_mem_put_cpu_buf(int32_t buf_handle) 
			"Unbalanced release Called buf_handle: %u, idx: %d",

			tbl.bufq[idx].buf_handle, idx);

	}

	mutex_unlock(&tbl.bufq[idx].ref_lock);



	if (unmap)

		mutex_destroy(&tbl.bufq[idx].ref_lock);



}

EXPORT_SYMBOL(cam_mem_put_cpu_buf);
@@ -1202,7 +1187,6 @@ int cam_mem_mgr_release(struct cam_mem_mgr_release_cmd *cmd) 


	CAM_DBG(CAM_MEM, "Releasing hdl = %x, idx = %d", cmd->buf_handle, idx);



	mutex_lock(&tbl.bufq[idx].ref_lock);

	kref_put(&tbl.bufq[idx].urefcount, cam_mem_util_unmap_dummy);



	urefcount = kref_read(&tbl.bufq[idx].urefcount);
@@ -1222,11 +1206,6 @@ int cam_mem_mgr_release(struct cam_mem_mgr_release_cmd *cmd) 
			"Called unmap from here, buf_handle: %u, idx: %d", cmd->buf_handle, idx);

	}



	mutex_unlock(&tbl.bufq[idx].ref_lock);



	if (unmap)

		mutex_destroy(&tbl.bufq[idx].ref_lock);



	return rc;

}

drivers/cam_req_mgr/cam_mem_mgr.h

+0 −2
Original line number Diff line number Diff line
@@ -48,7 +48,6 @@ enum cam_smmu_mapping_client { 
 * @smmu_mapping_client: Client buffer (User or kernel)

 * @urefcount:      Reference counter to track whether the buffer is

 *                  mapped and in use by umd

 * @ref_lock:       Mutex lock for refcount

 */

struct cam_mem_buf_queue {

	struct dma_buf *dma_buf;
@@ -67,7 +66,6 @@ struct cam_mem_buf_queue { 
	struct kref krefcount;

	enum cam_smmu_mapping_client smmu_mapping_client;

	struct kref urefcount;

	struct mutex ref_lock;

};



/**