drivers/gpu/drm/radeon/r600_dma.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2013 Advanced Micro Devices, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Authors: Alex Deucher
  */
 #include <drm/drmP.h>
 #include "radeon.h"
 #include "radeon_asic.h"
 #include "r600d.h"

 u32 r600_gpu_check_soft_reset(struct radeon_device *rdev);

 /*
  * DMA
  * Starting with R600, the GPU has an asynchronous
  * DMA engine.  The programming model is very similar
  * to the 3D engine (ring buffer, IBs, etc.), but the
  * DMA controller has it's own packet format that is
  * different form the PM4 format used by the 3D engine.
  * It supports copying data, writing embedded data,
  * solid fills, and a number of other things.  It also
  * has support for tiling/detiling of buffers.
  */

 /**
  * r600_dma_get_rptr - get the current read pointer
  *
  * @rdev: radeon_device pointer
  * @ring: radeon ring pointer
  *
  * Get the current rptr from the hardware (r6xx+).
  */
 uint32_t r600_dma_get_rptr(struct radeon_device *rdev,
 			   struct radeon_ring *ring)
 {
 	u32 rptr;

 	if (rdev->wb.enabled)
 		rptr = rdev->wb.wb[ring->rptr_offs/4];
 	else
 		rptr = RREG32(DMA_RB_RPTR);

 	return (rptr & 0x3fffc) >> 2;
 }

 /**
  * r600_dma_get_wptr - get the current write pointer
  *
  * @rdev: radeon_device pointer
  * @ring: radeon ring pointer
  *
  * Get the current wptr from the hardware (r6xx+).
  */
 uint32_t r600_dma_get_wptr(struct radeon_device *rdev,
 			   struct radeon_ring *ring)
 {
 	return (RREG32(DMA_RB_WPTR) & 0x3fffc) >> 2;
 }

 /**
  * r600_dma_set_wptr - commit the write pointer
  *
  * @rdev: radeon_device pointer
  * @ring: radeon ring pointer
  *
  * Write the wptr back to the hardware (r6xx+).
  */
 void r600_dma_set_wptr(struct radeon_device *rdev,
 		       struct radeon_ring *ring)
 {
 	WREG32(DMA_RB_WPTR, (ring->wptr << 2) & 0x3fffc);
 }

 /**
  * r600_dma_stop - stop the async dma engine
  *
  * @rdev: radeon_device pointer
  *
  * Stop the async dma engine (r6xx-evergreen).
  */
 void r600_dma_stop(struct radeon_device *rdev)
 {
 	u32 rb_cntl = RREG32(DMA_RB_CNTL);

 	if (rdev->asic->copy.copy_ring_index == R600_RING_TYPE_DMA_INDEX)
 		radeon_ttm_set_active_vram_size(rdev, rdev->mc.visible_vram_size);

 	rb_cntl &= ~DMA_RB_ENABLE;
 	WREG32(DMA_RB_CNTL, rb_cntl);

 	rdev->ring[R600_RING_TYPE_DMA_INDEX].ready = false;
 }

 /**
  * r600_dma_resume - setup and start the async dma engine
  *
  * @rdev: radeon_device pointer
  *
  * Set up the DMA ring buffer and enable it. (r6xx-evergreen).
  * Returns 0 for success, error for failure.
  */
 int r600_dma_resume(struct radeon_device *rdev)
 {
 	struct radeon_ring *ring = &rdev->ring[R600_RING_TYPE_DMA_INDEX];
 	u32 rb_cntl, dma_cntl, ib_cntl;
 	u32 rb_bufsz;
 	int r;

 	WREG32(DMA_SEM_INCOMPLETE_TIMER_CNTL, 0);
 	WREG32(DMA_SEM_WAIT_FAIL_TIMER_CNTL, 0);

 	/* Set ring buffer size in dwords */
 	rb_bufsz = order_base_2(ring->ring_size / 4);
 	rb_cntl = rb_bufsz << 1;
 #ifdef __BIG_ENDIAN
 	rb_cntl |= DMA_RB_SWAP_ENABLE | DMA_RPTR_WRITEBACK_SWAP_ENABLE;
 #endif
 	WREG32(DMA_RB_CNTL, rb_cntl);

 	/* Initialize the ring buffer's read and write pointers */
 	WREG32(DMA_RB_RPTR, 0);
 	WREG32(DMA_RB_WPTR, 0);

 	/* set the wb address whether it's enabled or not */
 	WREG32(DMA_RB_RPTR_ADDR_HI,
 	       upper_32_bits(rdev->wb.gpu_addr + R600_WB_DMA_RPTR_OFFSET) & 0xFF);
 	WREG32(DMA_RB_RPTR_ADDR_LO,
 	       ((rdev->wb.gpu_addr + R600_WB_DMA_RPTR_OFFSET) & 0xFFFFFFFC));

 	if (rdev->wb.enabled)
 		rb_cntl |= DMA_RPTR_WRITEBACK_ENABLE;

 	WREG32(DMA_RB_BASE, ring->gpu_addr >> 8);

 	/* enable DMA IBs */
 	ib_cntl = DMA_IB_ENABLE;
 #ifdef __BIG_ENDIAN
 	ib_cntl |= DMA_IB_SWAP_ENABLE;
 #endif
 	WREG32(DMA_IB_CNTL, ib_cntl);

 	dma_cntl = RREG32(DMA_CNTL);
 	dma_cntl &= ~CTXEMPTY_INT_ENABLE;
 	WREG32(DMA_CNTL, dma_cntl);

 	if (rdev->family >= CHIP_RV770)
 		WREG32(DMA_MODE, 1);

 	ring->wptr = 0;
 	WREG32(DMA_RB_WPTR, ring->wptr << 2);

 	WREG32(DMA_RB_CNTL, rb_cntl | DMA_RB_ENABLE);

 	ring->ready = true;

 	r = radeon_ring_test(rdev, R600_RING_TYPE_DMA_INDEX, ring);
 	if (r) {
 		ring->ready = false;
 		return r;
 	}

 	if (rdev->asic->copy.copy_ring_index == R600_RING_TYPE_DMA_INDEX)
 		radeon_ttm_set_active_vram_size(rdev, rdev->mc.real_vram_size);

 	return 0;
 }

 /**
  * r600_dma_fini - tear down the async dma engine
  *
  * @rdev: radeon_device pointer
  *
  * Stop the async dma engine and free the ring (r6xx-evergreen).
  */
 void r600_dma_fini(struct radeon_device *rdev)
 {
 	r600_dma_stop(rdev);
 	radeon_ring_fini(rdev, &rdev->ring[R600_RING_TYPE_DMA_INDEX]);
 }

 /**
  * r600_dma_is_lockup - Check if the DMA engine is locked up
  *
  * @rdev: radeon_device pointer
  * @ring: radeon_ring structure holding ring information
  *
  * Check if the async DMA engine is locked up.
  * Returns true if the engine appears to be locked up, false if not.
  */
 bool r600_dma_is_lockup(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	u32 reset_mask = r600_gpu_check_soft_reset(rdev);

 	if (!(reset_mask & RADEON_RESET_DMA)) {
 		radeon_ring_lockup_update(rdev, ring);
 		return false;
 	}
 	return radeon_ring_test_lockup(rdev, ring);
 }


 /**
  * r600_dma_ring_test - simple async dma engine test
  *
  * @rdev: radeon_device pointer
  * @ring: radeon_ring structure holding ring information
  *
  * Test the DMA engine by writing using it to write an
  * value to memory. (r6xx-SI).
  * Returns 0 for success, error for failure.
  */
 int r600_dma_ring_test(struct radeon_device *rdev,
 		       struct radeon_ring *ring)
 {
 	unsigned i;
 	int r;
 	unsigned index;
 	u32 tmp;
 	u64 gpu_addr;

 	if (ring->idx == R600_RING_TYPE_DMA_INDEX)
 		index = R600_WB_DMA_RING_TEST_OFFSET;
 	else
 		index = CAYMAN_WB_DMA1_RING_TEST_OFFSET;

 	gpu_addr = rdev->wb.gpu_addr + index;

 	tmp = 0xCAFEDEAD;
 	rdev->wb.wb[index/4] = cpu_to_le32(tmp);

 	r = radeon_ring_lock(rdev, ring, 4);
 	if (r) {
 		DRM_ERROR("radeon: dma failed to lock ring %d (%d).\n", ring->idx, r);
 		return r;
 	}
 	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1));
 	radeon_ring_write(ring, lower_32_bits(gpu_addr));
 	radeon_ring_write(ring, upper_32_bits(gpu_addr) & 0xff);
 	radeon_ring_write(ring, 0xDEADBEEF);
 	radeon_ring_unlock_commit(rdev, ring, false);

 	for (i = 0; i < rdev->usec_timeout; i++) {
 		tmp = le32_to_cpu(rdev->wb.wb[index/4]);
 		if (tmp == 0xDEADBEEF)
 			break;
 		DRM_UDELAY(1);
 	}

 	if (i < rdev->usec_timeout) {
 		DRM_INFO("ring test on %d succeeded in %d usecs\n", ring->idx, i);
 	} else {
 		DRM_ERROR("radeon: ring %d test failed (0x%08X)\n",
 			  ring->idx, tmp);
 		r = -EINVAL;
 	}
 	return r;
 }

 /**
  * r600_dma_fence_ring_emit - emit a fence on the DMA ring
  *
  * @rdev: radeon_device pointer
  * @fence: radeon fence object
  *
  * Add a DMA fence packet to the ring to write
  * the fence seq number and DMA trap packet to generate
  * an interrupt if needed (r6xx-r7xx).
  */
 void r600_dma_fence_ring_emit(struct radeon_device *rdev,
 			      struct radeon_fence *fence)
 {
 	struct radeon_ring *ring = &rdev->ring[fence->ring];
 	u64 addr = rdev->fence_drv[fence->ring].gpu_addr;

 	/* write the fence */
 	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_FENCE, 0, 0, 0));
 	radeon_ring_write(ring, addr & 0xfffffffc);
 	radeon_ring_write(ring, (upper_32_bits(addr) & 0xff));
 	radeon_ring_write(ring, lower_32_bits(fence->seq));
 	/* generate an interrupt */
 	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_TRAP, 0, 0, 0));
 }

 /**
  * r600_dma_semaphore_ring_emit - emit a semaphore on the dma ring
  *
  * @rdev: radeon_device pointer
  * @ring: radeon_ring structure holding ring information
  * @semaphore: radeon semaphore object
  * @emit_wait: wait or signal semaphore
  *
  * Add a DMA semaphore packet to the ring wait on or signal
  * other rings (r6xx-SI).
  */
 bool r600_dma_semaphore_ring_emit(struct radeon_device *rdev,
 				  struct radeon_ring *ring,
 				  struct radeon_semaphore *semaphore,
 				  bool emit_wait)
 {
 	u64 addr = semaphore->gpu_addr;
 	u32 s = emit_wait ? 0 : 1;

 	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_SEMAPHORE, 0, s, 0));
 	radeon_ring_write(ring, addr & 0xfffffffc);
 	radeon_ring_write(ring, upper_32_bits(addr) & 0xff);

 	return true;
 }

 /**
  * r600_dma_ib_test - test an IB on the DMA engine
  *
  * @rdev: radeon_device pointer
  * @ring: radeon_ring structure holding ring information
  *
  * Test a simple IB in the DMA ring (r6xx-SI).
  * Returns 0 on success, error on failure.
  */
 int r600_dma_ib_test(struct radeon_device *rdev, struct radeon_ring *ring)
 {
 	struct radeon_ib ib;
 	unsigned i;
 	unsigned index;
 	int r;
 	u32 tmp = 0;
 	u64 gpu_addr;

 	if (ring->idx == R600_RING_TYPE_DMA_INDEX)
 		index = R600_WB_DMA_RING_TEST_OFFSET;
 	else
 		index = CAYMAN_WB_DMA1_RING_TEST_OFFSET;

 	gpu_addr = rdev->wb.gpu_addr + index;

 	r = radeon_ib_get(rdev, ring->idx, &ib, NULL, 256);
 	if (r) {
 		DRM_ERROR("radeon: failed to get ib (%d).\n", r);
 		return r;
 	}

 	ib.ptr[0] = DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1);
 	ib.ptr[1] = lower_32_bits(gpu_addr);
 	ib.ptr[2] = upper_32_bits(gpu_addr) & 0xff;
 	ib.ptr[3] = 0xDEADBEEF;
 	ib.length_dw = 4;

 	r = radeon_ib_schedule(rdev, &ib, NULL, false);
 	if (r) {
 		radeon_ib_free(rdev, &ib);
 		DRM_ERROR("radeon: failed to schedule ib (%d).\n", r);
 		return r;
 	}
 	r = radeon_fence_wait(ib.fence, false);
 	if (r) {
 		DRM_ERROR("radeon: fence wait failed (%d).\n", r);
 		return r;
 	}
 	for (i = 0; i < rdev->usec_timeout; i++) {
 		tmp = le32_to_cpu(rdev->wb.wb[index/4]);
 		if (tmp == 0xDEADBEEF)
 			break;
 		DRM_UDELAY(1);
 	}
 	if (i < rdev->usec_timeout) {
 		DRM_INFO("ib test on ring %d succeeded in %u usecs\n", ib.fence->ring, i);
 	} else {
 		DRM_ERROR("radeon: ib test failed (0x%08X)\n", tmp);
 		r = -EINVAL;
 	}
 	radeon_ib_free(rdev, &ib);
 	return r;
 }

 /**
  * r600_dma_ring_ib_execute - Schedule an IB on the DMA engine
  *
  * @rdev: radeon_device pointer
  * @ib: IB object to schedule
  *
  * Schedule an IB in the DMA ring (r6xx-r7xx).
  */
 void r600_dma_ring_ib_execute(struct radeon_device *rdev, struct radeon_ib *ib)
 {
 	struct radeon_ring *ring = &rdev->ring[ib->ring];

 	if (rdev->wb.enabled) {
 		u32 next_rptr = ring->wptr + 4;
 		while ((next_rptr & 7) != 5)
 			next_rptr++;
 		next_rptr += 3;
 		radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1));
 		radeon_ring_write(ring, ring->next_rptr_gpu_addr & 0xfffffffc);
 		radeon_ring_write(ring, upper_32_bits(ring->next_rptr_gpu_addr) & 0xff);
 		radeon_ring_write(ring, next_rptr);
 	}

 	/* The indirect buffer packet must end on an 8 DW boundary in the DMA ring.
 	 * Pad as necessary with NOPs.
 	 */
 	while ((ring->wptr & 7) != 5)
 		radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_NOP, 0, 0, 0));
 	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_INDIRECT_BUFFER, 0, 0, 0));
 	radeon_ring_write(ring, (ib->gpu_addr & 0xFFFFFFE0));
 	radeon_ring_write(ring, (ib->length_dw << 16) | (upper_32_bits(ib->gpu_addr) & 0xFF));

 }

 /**
  * r600_copy_dma - copy pages using the DMA engine
  *
  * @rdev: radeon_device pointer
  * @src_offset: src GPU address
  * @dst_offset: dst GPU address
  * @num_gpu_pages: number of GPU pages to xfer
  * @resv: reservation object to sync to
  *
  * Copy GPU paging using the DMA engine (r6xx).
  * Used by the radeon ttm implementation to move pages if
  * registered as the asic copy callback.
  */
 struct radeon_fence *r600_copy_dma(struct radeon_device *rdev,
 				   uint64_t src_offset, uint64_t dst_offset,
 				   unsigned num_gpu_pages,
 				   struct reservation_object *resv)
 {
 	struct radeon_semaphore *sem = NULL;
 	struct radeon_fence *fence;
 	int ring_index = rdev->asic->copy.dma_ring_index;
 	struct radeon_ring *ring = &rdev->ring[ring_index];
 	u32 size_in_dw, cur_size_in_dw;
 	int i, num_loops;
 	int r = 0;

 	r = radeon_semaphore_create(rdev, &sem);
 	if (r) {
 		DRM_ERROR("radeon: moving bo (%d).\n", r);
 		return ERR_PTR(r);
 	}

 	size_in_dw = (num_gpu_pages << RADEON_GPU_PAGE_SHIFT) / 4;
 	num_loops = DIV_ROUND_UP(size_in_dw, 0xFFFE);
 	r = radeon_ring_lock(rdev, ring, num_loops * 4 + 8);
 	if (r) {
 		DRM_ERROR("radeon: moving bo (%d).\n", r);
 		radeon_semaphore_free(rdev, &sem, NULL);
 		return ERR_PTR(r);
 	}

 	radeon_semaphore_sync_resv(rdev, sem, resv, false);
 	radeon_semaphore_sync_rings(rdev, sem, ring->idx);

 	for (i = 0; i < num_loops; i++) {
 		cur_size_in_dw = size_in_dw;
 		if (cur_size_in_dw > 0xFFFE)
 			cur_size_in_dw = 0xFFFE;
 		size_in_dw -= cur_size_in_dw;
 		radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_COPY, 0, 0, cur_size_in_dw));
 		radeon_ring_write(ring, dst_offset & 0xfffffffc);
 		radeon_ring_write(ring, src_offset & 0xfffffffc);
 		radeon_ring_write(ring, (((upper_32_bits(dst_offset) & 0xff) << 16) |
 					 (upper_32_bits(src_offset) & 0xff)));
 		src_offset += cur_size_in_dw * 4;
 		dst_offset += cur_size_in_dw * 4;
 	}

 	r = radeon_fence_emit(rdev, &fence, ring->idx);
 	if (r) {
 		radeon_ring_unlock_undo(rdev, ring);
 		radeon_semaphore_free(rdev, &sem, NULL);
 		return ERR_PTR(r);
 	}

 	radeon_ring_unlock_commit(rdev, ring, false);
 	radeon_semaphore_free(rdev, &sem, fence);

 	return fence;
 }
	/*
	* Copyright 2013 Advanced Micro Devices, Inc.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	* OTHER DEALINGS IN THE SOFTWARE.
	*
	* Authors: Alex Deucher
	*/
	#include <drm/drmP.h>
	#include "radeon.h"
	#include "radeon_asic.h"
	#include "r600d.h"

	u32 r600_gpu_check_soft_reset(struct radeon_device *rdev);

	/*
	* DMA
	* Starting with R600, the GPU has an asynchronous
	* DMA engine. The programming model is very similar
	* to the 3D engine (ring buffer, IBs, etc.), but the
	* DMA controller has it's own packet format that is
	* different form the PM4 format used by the 3D engine.
	* It supports copying data, writing embedded data,
	* solid fills, and a number of other things. It also
	* has support for tiling/detiling of buffers.
	*/

	/**
	* r600_dma_get_rptr - get the current read pointer
	*
	* @rdev: radeon_device pointer
	* @ring: radeon ring pointer
	*
	* Get the current rptr from the hardware (r6xx+).
	*/
	uint32_t r600_dma_get_rptr(struct radeon_device *rdev,
	struct radeon_ring *ring)
	{
	u32 rptr;

	if (rdev->wb.enabled)
	rptr = rdev->wb.wb[ring->rptr_offs/4];
	else
	rptr = RREG32(DMA_RB_RPTR);

	return (rptr & 0x3fffc) >> 2;
	}

	/**
	* r600_dma_get_wptr - get the current write pointer
	*
	* @rdev: radeon_device pointer
	* @ring: radeon ring pointer
	*
	* Get the current wptr from the hardware (r6xx+).
	*/
	uint32_t r600_dma_get_wptr(struct radeon_device *rdev,
	struct radeon_ring *ring)
	{
	return (RREG32(DMA_RB_WPTR) & 0x3fffc) >> 2;
	}

	/**
	* r600_dma_set_wptr - commit the write pointer
	*
	* @rdev: radeon_device pointer
	* @ring: radeon ring pointer
	*
	* Write the wptr back to the hardware (r6xx+).
	*/
	void r600_dma_set_wptr(struct radeon_device *rdev,
	struct radeon_ring *ring)
	{
	WREG32(DMA_RB_WPTR, (ring->wptr << 2) & 0x3fffc);
	}

	/**
	* r600_dma_stop - stop the async dma engine
	*
	* @rdev: radeon_device pointer
	*
	* Stop the async dma engine (r6xx-evergreen).
	*/
	void r600_dma_stop(struct radeon_device *rdev)
	{
	u32 rb_cntl = RREG32(DMA_RB_CNTL);

	if (rdev->asic->copy.copy_ring_index == R600_RING_TYPE_DMA_INDEX)
	radeon_ttm_set_active_vram_size(rdev, rdev->mc.visible_vram_size);

	rb_cntl &= ~DMA_RB_ENABLE;
	WREG32(DMA_RB_CNTL, rb_cntl);

	rdev->ring[R600_RING_TYPE_DMA_INDEX].ready = false;
	}

	/**
	* r600_dma_resume - setup and start the async dma engine
	*
	* @rdev: radeon_device pointer
	*
	* Set up the DMA ring buffer and enable it. (r6xx-evergreen).
	* Returns 0 for success, error for failure.
	*/
	int r600_dma_resume(struct radeon_device *rdev)
	{
	struct radeon_ring *ring = &rdev->ring[R600_RING_TYPE_DMA_INDEX];
	u32 rb_cntl, dma_cntl, ib_cntl;
	u32 rb_bufsz;
	int r;

	WREG32(DMA_SEM_INCOMPLETE_TIMER_CNTL, 0);
	WREG32(DMA_SEM_WAIT_FAIL_TIMER_CNTL, 0);

	/* Set ring buffer size in dwords */
	rb_bufsz = order_base_2(ring->ring_size / 4);
	rb_cntl = rb_bufsz << 1;
	#ifdef __BIG_ENDIAN
	rb_cntl \|= DMA_RB_SWAP_ENABLE \| DMA_RPTR_WRITEBACK_SWAP_ENABLE;
	#endif
	WREG32(DMA_RB_CNTL, rb_cntl);

	/* Initialize the ring buffer's read and write pointers */
	WREG32(DMA_RB_RPTR, 0);
	WREG32(DMA_RB_WPTR, 0);

	/* set the wb address whether it's enabled or not */
	WREG32(DMA_RB_RPTR_ADDR_HI,
	upper_32_bits(rdev->wb.gpu_addr + R600_WB_DMA_RPTR_OFFSET) & 0xFF);
	WREG32(DMA_RB_RPTR_ADDR_LO,
	((rdev->wb.gpu_addr + R600_WB_DMA_RPTR_OFFSET) & 0xFFFFFFFC));

	if (rdev->wb.enabled)
	rb_cntl \|= DMA_RPTR_WRITEBACK_ENABLE;

	WREG32(DMA_RB_BASE, ring->gpu_addr >> 8);

	/* enable DMA IBs */
	ib_cntl = DMA_IB_ENABLE;
	#ifdef __BIG_ENDIAN
	ib_cntl \|= DMA_IB_SWAP_ENABLE;
	#endif
	WREG32(DMA_IB_CNTL, ib_cntl);

	dma_cntl = RREG32(DMA_CNTL);
	dma_cntl &= ~CTXEMPTY_INT_ENABLE;
	WREG32(DMA_CNTL, dma_cntl);

	if (rdev->family >= CHIP_RV770)
	WREG32(DMA_MODE, 1);

	ring->wptr = 0;
	WREG32(DMA_RB_WPTR, ring->wptr << 2);

	WREG32(DMA_RB_CNTL, rb_cntl \| DMA_RB_ENABLE);

	ring->ready = true;

	r = radeon_ring_test(rdev, R600_RING_TYPE_DMA_INDEX, ring);
	if (r) {
	ring->ready = false;
	return r;
	}

	if (rdev->asic->copy.copy_ring_index == R600_RING_TYPE_DMA_INDEX)
	radeon_ttm_set_active_vram_size(rdev, rdev->mc.real_vram_size);

	return 0;
	}

	/**
	* r600_dma_fini - tear down the async dma engine
	*
	* @rdev: radeon_device pointer
	*
	* Stop the async dma engine and free the ring (r6xx-evergreen).
	*/
	void r600_dma_fini(struct radeon_device *rdev)
	{
	r600_dma_stop(rdev);
	radeon_ring_fini(rdev, &rdev->ring[R600_RING_TYPE_DMA_INDEX]);
	}

	/**
	* r600_dma_is_lockup - Check if the DMA engine is locked up
	*
	* @rdev: radeon_device pointer
	* @ring: radeon_ring structure holding ring information
	*
	* Check if the async DMA engine is locked up.
	* Returns true if the engine appears to be locked up, false if not.
	*/
	bool r600_dma_is_lockup(struct radeon_device rdev, struct radeon_ring ring)
	{
	u32 reset_mask = r600_gpu_check_soft_reset(rdev);

	if (!(reset_mask & RADEON_RESET_DMA)) {
	radeon_ring_lockup_update(rdev, ring);
	return false;
	}
	return radeon_ring_test_lockup(rdev, ring);
	}


	/**
	* r600_dma_ring_test - simple async dma engine test
	*
	* @rdev: radeon_device pointer
	* @ring: radeon_ring structure holding ring information
	*
	* Test the DMA engine by writing using it to write an
	* value to memory. (r6xx-SI).
	* Returns 0 for success, error for failure.
	*/
	int r600_dma_ring_test(struct radeon_device *rdev,
	struct radeon_ring *ring)
	{
	unsigned i;
	int r;
	unsigned index;
	u32 tmp;
	u64 gpu_addr;

	if (ring->idx == R600_RING_TYPE_DMA_INDEX)
	index = R600_WB_DMA_RING_TEST_OFFSET;
	else
	index = CAYMAN_WB_DMA1_RING_TEST_OFFSET;

	gpu_addr = rdev->wb.gpu_addr + index;

	tmp = 0xCAFEDEAD;
	rdev->wb.wb[index/4] = cpu_to_le32(tmp);

	r = radeon_ring_lock(rdev, ring, 4);
	if (r) {
	DRM_ERROR("radeon: dma failed to lock ring %d (%d).\n", ring->idx, r);
	return r;
	}
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1));
	radeon_ring_write(ring, lower_32_bits(gpu_addr));
	radeon_ring_write(ring, upper_32_bits(gpu_addr) & 0xff);
	radeon_ring_write(ring, 0xDEADBEEF);
	radeon_ring_unlock_commit(rdev, ring, false);

	for (i = 0; i < rdev->usec_timeout; i++) {
	tmp = le32_to_cpu(rdev->wb.wb[index/4]);
	if (tmp == 0xDEADBEEF)
	break;
	DRM_UDELAY(1);
	}

	if (i < rdev->usec_timeout) {
	DRM_INFO("ring test on %d succeeded in %d usecs\n", ring->idx, i);
	} else {
	DRM_ERROR("radeon: ring %d test failed (0x%08X)\n",
	ring->idx, tmp);
	r = -EINVAL;
	}
	return r;
	}

	/**
	* r600_dma_fence_ring_emit - emit a fence on the DMA ring
	*
	* @rdev: radeon_device pointer
	* @fence: radeon fence object
	*
	* Add a DMA fence packet to the ring to write
	* the fence seq number and DMA trap packet to generate
	* an interrupt if needed (r6xx-r7xx).
	*/
	void r600_dma_fence_ring_emit(struct radeon_device *rdev,
	struct radeon_fence *fence)
	{
	struct radeon_ring *ring = &rdev->ring[fence->ring];
	u64 addr = rdev->fence_drv[fence->ring].gpu_addr;

	/* write the fence */
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_FENCE, 0, 0, 0));
	radeon_ring_write(ring, addr & 0xfffffffc);
	radeon_ring_write(ring, (upper_32_bits(addr) & 0xff));
	radeon_ring_write(ring, lower_32_bits(fence->seq));
	/* generate an interrupt */
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_TRAP, 0, 0, 0));
	}

	/**
	* r600_dma_semaphore_ring_emit - emit a semaphore on the dma ring
	*
	* @rdev: radeon_device pointer
	* @ring: radeon_ring structure holding ring information
	* @semaphore: radeon semaphore object
	* @emit_wait: wait or signal semaphore
	*
	* Add a DMA semaphore packet to the ring wait on or signal
	* other rings (r6xx-SI).
	*/
	bool r600_dma_semaphore_ring_emit(struct radeon_device *rdev,
	struct radeon_ring *ring,
	struct radeon_semaphore *semaphore,
	bool emit_wait)
	{
	u64 addr = semaphore->gpu_addr;
	u32 s = emit_wait ? 0 : 1;

	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_SEMAPHORE, 0, s, 0));
	radeon_ring_write(ring, addr & 0xfffffffc);
	radeon_ring_write(ring, upper_32_bits(addr) & 0xff);

	return true;
	}

	/**
	* r600_dma_ib_test - test an IB on the DMA engine
	*
	* @rdev: radeon_device pointer
	* @ring: radeon_ring structure holding ring information
	*
	* Test a simple IB in the DMA ring (r6xx-SI).
	* Returns 0 on success, error on failure.
	*/
	int r600_dma_ib_test(struct radeon_device rdev, struct radeon_ring ring)
	{
	struct radeon_ib ib;
	unsigned i;
	unsigned index;
	int r;
	u32 tmp = 0;
	u64 gpu_addr;

	if (ring->idx == R600_RING_TYPE_DMA_INDEX)
	index = R600_WB_DMA_RING_TEST_OFFSET;
	else
	index = CAYMAN_WB_DMA1_RING_TEST_OFFSET;

	gpu_addr = rdev->wb.gpu_addr + index;

	r = radeon_ib_get(rdev, ring->idx, &ib, NULL, 256);
	if (r) {
	DRM_ERROR("radeon: failed to get ib (%d).\n", r);
	return r;
	}

	ib.ptr[0] = DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1);
	ib.ptr[1] = lower_32_bits(gpu_addr);
	ib.ptr[2] = upper_32_bits(gpu_addr) & 0xff;
	ib.ptr[3] = 0xDEADBEEF;
	ib.length_dw = 4;

	r = radeon_ib_schedule(rdev, &ib, NULL, false);
	if (r) {
	radeon_ib_free(rdev, &ib);
	DRM_ERROR("radeon: failed to schedule ib (%d).\n", r);
	return r;
	}
	r = radeon_fence_wait(ib.fence, false);
	if (r) {
	DRM_ERROR("radeon: fence wait failed (%d).\n", r);
	return r;
	}
	for (i = 0; i < rdev->usec_timeout; i++) {
	tmp = le32_to_cpu(rdev->wb.wb[index/4]);
	if (tmp == 0xDEADBEEF)
	break;
	DRM_UDELAY(1);
	}
	if (i < rdev->usec_timeout) {
	DRM_INFO("ib test on ring %d succeeded in %u usecs\n", ib.fence->ring, i);
	} else {
	DRM_ERROR("radeon: ib test failed (0x%08X)\n", tmp);
	r = -EINVAL;
	}
	radeon_ib_free(rdev, &ib);
	return r;
	}

	/**
	* r600_dma_ring_ib_execute - Schedule an IB on the DMA engine
	*
	* @rdev: radeon_device pointer
	* @ib: IB object to schedule
	*
	* Schedule an IB in the DMA ring (r6xx-r7xx).
	*/
	void r600_dma_ring_ib_execute(struct radeon_device rdev, struct radeon_ib ib)
	{
	struct radeon_ring *ring = &rdev->ring[ib->ring];

	if (rdev->wb.enabled) {
	u32 next_rptr = ring->wptr + 4;
	while ((next_rptr & 7) != 5)
	next_rptr++;
	next_rptr += 3;
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_WRITE, 0, 0, 1));
	radeon_ring_write(ring, ring->next_rptr_gpu_addr & 0xfffffffc);
	radeon_ring_write(ring, upper_32_bits(ring->next_rptr_gpu_addr) & 0xff);
	radeon_ring_write(ring, next_rptr);
	}

	/* The indirect buffer packet must end on an 8 DW boundary in the DMA ring.
	* Pad as necessary with NOPs.
	*/
	while ((ring->wptr & 7) != 5)
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_NOP, 0, 0, 0));
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_INDIRECT_BUFFER, 0, 0, 0));
	radeon_ring_write(ring, (ib->gpu_addr & 0xFFFFFFE0));
	radeon_ring_write(ring, (ib->length_dw << 16) \| (upper_32_bits(ib->gpu_addr) & 0xFF));

	}

	/**
	* r600_copy_dma - copy pages using the DMA engine
	*
	* @rdev: radeon_device pointer
	* @src_offset: src GPU address
	* @dst_offset: dst GPU address
	* @num_gpu_pages: number of GPU pages to xfer
	* @resv: reservation object to sync to
	*
	* Copy GPU paging using the DMA engine (r6xx).
	* Used by the radeon ttm implementation to move pages if
	* registered as the asic copy callback.
	*/
	struct radeon_fence r600_copy_dma(struct radeon_device rdev,
	uint64_t src_offset, uint64_t dst_offset,
	unsigned num_gpu_pages,
	struct reservation_object *resv)
	{
	struct radeon_semaphore *sem = NULL;
	struct radeon_fence *fence;
	int ring_index = rdev->asic->copy.dma_ring_index;
	struct radeon_ring *ring = &rdev->ring[ring_index];
	u32 size_in_dw, cur_size_in_dw;
	int i, num_loops;
	int r = 0;

	r = radeon_semaphore_create(rdev, &sem);
	if (r) {
	DRM_ERROR("radeon: moving bo (%d).\n", r);
	return ERR_PTR(r);
	}

	size_in_dw = (num_gpu_pages << RADEON_GPU_PAGE_SHIFT) / 4;
	num_loops = DIV_ROUND_UP(size_in_dw, 0xFFFE);
	r = radeon_ring_lock(rdev, ring, num_loops * 4 + 8);
	if (r) {
	DRM_ERROR("radeon: moving bo (%d).\n", r);
	radeon_semaphore_free(rdev, &sem, NULL);
	return ERR_PTR(r);
	}

	radeon_semaphore_sync_resv(rdev, sem, resv, false);
	radeon_semaphore_sync_rings(rdev, sem, ring->idx);

	for (i = 0; i < num_loops; i++) {
	cur_size_in_dw = size_in_dw;
	if (cur_size_in_dw > 0xFFFE)
	cur_size_in_dw = 0xFFFE;
	size_in_dw -= cur_size_in_dw;
	radeon_ring_write(ring, DMA_PACKET(DMA_PACKET_COPY, 0, 0, cur_size_in_dw));
	radeon_ring_write(ring, dst_offset & 0xfffffffc);
	radeon_ring_write(ring, src_offset & 0xfffffffc);
	radeon_ring_write(ring, (((upper_32_bits(dst_offset) & 0xff) << 16) \|
	(upper_32_bits(src_offset) & 0xff)));
	src_offset += cur_size_in_dw * 4;
	dst_offset += cur_size_in_dw * 4;
	}

	r = radeon_fence_emit(rdev, &fence, ring->idx);
	if (r) {
	radeon_ring_unlock_undo(rdev, ring);
	radeon_semaphore_free(rdev, &sem, NULL);
	return ERR_PTR(r);
	}

	radeon_ring_unlock_commit(rdev, ring, false);
	radeon_semaphore_free(rdev, &sem, fence);

	return fence;
	}