Commit 5a142824 authored by Tao Zhou's avatar Tao Zhou Committed by Alex Deucher
Browse files

drm/amdgpu: read CPER ring via debugfs 



We read CPER data from read pointer to write pointer without changing
the pointers.

Signed-off-by: default avatarTao Zhou <tao.zhou1@amd.com>
Reviewed-by: default avatarHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 4d614ce8

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

+36 −11
Original line number Diff line number Diff line
@@ -500,6 +500,7 @@ static ssize_t amdgpu_debugfs_ring_read(struct file *f, char __user *buf, 
{

	struct amdgpu_ring *ring = file_inode(f)->i_private;

	uint32_t value, result, early[3];

	uint64_t p;

	loff_t i;

	int r;
@@ -523,6 +524,7 @@ static ssize_t amdgpu_debugfs_ring_read(struct file *f, char __user *buf, 
		}

	}



	if (ring->funcs->type != AMDGPU_RING_TYPE_CPER) {

		while (size) {

			if (*pos >= (ring->ring_size + 12))

				return result;
@@ -536,6 +538,29 @@ static ssize_t amdgpu_debugfs_ring_read(struct file *f, char __user *buf, 
			size -= 4;

			*pos += 4;

		}

	} else {

		p = early[0];

		if (early[0] <= early[1])

			size = (early[1] - early[0]);

		else

			size = ring->ring_size - (early[0] - early[1]);



		while (size) {

			if (p == early[1])

				return result;



			value = ring->ring[p];

			r = put_user(value, (uint32_t *)buf);

			if (r)

				return r;



			buf += 4;

			result += 4;

			size--;

			p++;

			p &= ring->ptr_mask;

		}

	}



	return result;

}