drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c - third_party/kernel - Git at Google

 /*
  * Copyright 2014 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.
  *
  */

 #include <linux/dma-mapping.h>

 #include "amdgpu.h"
 #include "amdgpu_ih.h"

 /**
  * amdgpu_ih_ring_init - initialize the IH state
  *
  * @adev: amdgpu_device pointer
  * @ih: ih ring to initialize
  * @ring_size: ring size to allocate
  * @use_bus_addr: true when we can use dma_alloc_coherent
  *
  * Initializes the IH state and allocates a buffer
  * for the IH ring buffer.
  * Returns 0 for success, errors for failure.
  */
 int amdgpu_ih_ring_init(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih,
 			unsigned ring_size, bool use_bus_addr)
 {
 	u32 rb_bufsz;
 	int r;

 	/* Align ring size */
 	rb_bufsz = order_base_2(ring_size / 4);
 	ring_size = (1 << rb_bufsz) * 4;
 	ih->ring_size = ring_size;
 	ih->ptr_mask = ih->ring_size - 1;
 	ih->rptr = 0;
 	ih->use_bus_addr = use_bus_addr;

 	if (use_bus_addr) {
 		dma_addr_t dma_addr;

 		if (ih->ring)
 			return 0;

 		/* add 8 bytes for the rptr/wptr shadows and
 		 * add them to the end of the ring allocation.
 		 */
 		ih->ring = dma_alloc_coherent(adev->dev, ih->ring_size + 8,
 					      &dma_addr, GFP_KERNEL);
 		if (ih->ring == NULL)
 			return -ENOMEM;

 		ih->gpu_addr = dma_addr;
 		ih->wptr_addr = dma_addr + ih->ring_size;
 		ih->wptr_cpu = &ih->ring[ih->ring_size / 4];
 		ih->rptr_addr = dma_addr + ih->ring_size + 4;
 		ih->rptr_cpu = &ih->ring[(ih->ring_size / 4) + 1];
 	} else {
 		unsigned wptr_offs, rptr_offs;

 		r = amdgpu_device_wb_get(adev, &wptr_offs);
 		if (r)
 			return r;

 		r = amdgpu_device_wb_get(adev, &rptr_offs);
 		if (r) {
 			amdgpu_device_wb_free(adev, wptr_offs);
 			return r;
 		}

 		r = amdgpu_bo_create_kernel(adev, ih->ring_size, PAGE_SIZE,
 					    AMDGPU_GEM_DOMAIN_GTT,
 					    &ih->ring_obj, &ih->gpu_addr,
 					    (void **)&ih->ring);
 		if (r) {
 			amdgpu_device_wb_free(adev, rptr_offs);
 			amdgpu_device_wb_free(adev, wptr_offs);
 			return r;
 		}

 		ih->wptr_addr = adev->wb.gpu_addr + wptr_offs * 4;
 		ih->wptr_cpu = &adev->wb.wb[wptr_offs];
 		ih->rptr_addr = adev->wb.gpu_addr + rptr_offs * 4;
 		ih->rptr_cpu = &adev->wb.wb[rptr_offs];
 	}

 	init_waitqueue_head(&ih->wait_process);
 	return 0;
 }

 /**
  * amdgpu_ih_ring_fini - tear down the IH state
  *
  * @adev: amdgpu_device pointer
  * @ih: ih ring to tear down
  *
  * Tears down the IH state and frees buffer
  * used for the IH ring buffer.
  */
 void amdgpu_ih_ring_fini(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
 {

 	if (!ih->ring)
 		return;

 	if (ih->use_bus_addr) {

 		/* add 8 bytes for the rptr/wptr shadows and
 		 * add them to the end of the ring allocation.
 		 */
 		dma_free_coherent(adev->dev, ih->ring_size + 8,
 				  (void *)ih->ring, ih->gpu_addr);
 		ih->ring = NULL;
 	} else {
 		amdgpu_bo_free_kernel(&ih->ring_obj, &ih->gpu_addr,
 				      (void **)&ih->ring);
 		amdgpu_device_wb_free(adev, (ih->wptr_addr - ih->gpu_addr) / 4);
 		amdgpu_device_wb_free(adev, (ih->rptr_addr - ih->gpu_addr) / 4);
 	}
 }

 /**
  * amdgpu_ih_ring_write - write IV to the ring buffer
  *
  * @ih: ih ring to write to
  * @iv: the iv to write
  * @num_dw: size of the iv in dw
  *
  * Writes an IV to the ring buffer using the CPU and increment the wptr.
  * Used for testing and delegating IVs to a software ring.
  */
 void amdgpu_ih_ring_write(struct amdgpu_ih_ring *ih, const uint32_t *iv,
 			  unsigned int num_dw)
 {
 	uint32_t wptr = le32_to_cpu(*ih->wptr_cpu) >> 2;
 	unsigned int i;

 	for (i = 0; i < num_dw; ++i)
 	        ih->ring[wptr++] = cpu_to_le32(iv[i]);

 	wptr <<= 2;
 	wptr &= ih->ptr_mask;

 	/* Only commit the new wptr if we don't overflow */
 	if (wptr != READ_ONCE(ih->rptr)) {
 		wmb();
 		WRITE_ONCE(*ih->wptr_cpu, cpu_to_le32(wptr));
 	}
 }

 /* Waiter helper that checks current rptr matches or passes checkpoint wptr */
 static bool amdgpu_ih_has_checkpoint_processed(struct amdgpu_device *adev,
 					struct amdgpu_ih_ring *ih,
 					uint32_t checkpoint_wptr,
 					uint32_t *prev_rptr)
 {
 	uint32_t cur_rptr = ih->rptr | (*prev_rptr & ~ih->ptr_mask);

 	/* rptr has wrapped. */
 	if (cur_rptr < *prev_rptr)
 		cur_rptr += ih->ptr_mask + 1;
 	*prev_rptr = cur_rptr;

 	/* check ring is empty to workaround missing wptr overflow flag */
 	return cur_rptr >= checkpoint_wptr ||
 	       (cur_rptr & ih->ptr_mask) == amdgpu_ih_get_wptr(adev, ih);
 }

 /**
  * amdgpu_ih_wait_on_checkpoint_process - wait to process IVs up to checkpoint
  *
  * @adev: amdgpu_device pointer
  * @ih: ih ring to process
  *
  * Used to ensure ring has processed IVs up to the checkpoint write pointer.
  */
 int amdgpu_ih_wait_on_checkpoint_process(struct amdgpu_device *adev,
 					struct amdgpu_ih_ring *ih)
 {
 	uint32_t checkpoint_wptr, rptr;

 	if (!ih->enabled || adev->shutdown)
 		return -ENODEV;

 	checkpoint_wptr = amdgpu_ih_get_wptr(adev, ih);
 	/* Order wptr with rptr. */
 	rmb();
 	rptr = READ_ONCE(ih->rptr);

 	/* wptr has wrapped. */
 	if (rptr > checkpoint_wptr)
 		checkpoint_wptr += ih->ptr_mask + 1;

 	return wait_event_interruptible(ih->wait_process,
 				amdgpu_ih_has_checkpoint_processed(adev, ih,
 						checkpoint_wptr, &rptr));
 }

 /**
  * amdgpu_ih_process - interrupt handler
  *
  * @adev: amdgpu_device pointer
  * @ih: ih ring to process
  *
  * Interrupt hander (VI), walk the IH ring.
  * Returns irq process return code.
  */
 int amdgpu_ih_process(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
 {
 	unsigned int count;
 	u32 wptr;

 	if (!ih->enabled || adev->shutdown)
 		return IRQ_NONE;

 	wptr = amdgpu_ih_get_wptr(adev, ih);

 restart_ih:
 	count  = AMDGPU_IH_MAX_NUM_IVS;
 	DRM_DEBUG("%s: rptr %d, wptr %d\n", __func__, ih->rptr, wptr);

 	/* Order reading of wptr vs. reading of IH ring data */
 	rmb();

 	while (ih->rptr != wptr && --count) {
 		amdgpu_irq_dispatch(adev, ih);
 		ih->rptr &= ih->ptr_mask;
 	}

 	amdgpu_ih_set_rptr(adev, ih);
 	wake_up_all(&ih->wait_process);

 	/* make sure wptr hasn't changed while processing */
 	wptr = amdgpu_ih_get_wptr(adev, ih);
 	if (wptr != ih->rptr)
 		goto restart_ih;

 	return IRQ_HANDLED;
 }

 /**
  * amdgpu_ih_decode_iv_helper - decode an interrupt vector
  *
  * @adev: amdgpu_device pointer
  * @ih: ih ring to process
  * @entry: IV entry
  *
  * Decodes the interrupt vector at the current rptr
  * position and also advance the position for for Vega10
  * and later GPUs.
  */
 void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
 				struct amdgpu_ih_ring *ih,
 				struct amdgpu_iv_entry *entry)
 {
 	/* wptr/rptr are in bytes! */
 	u32 ring_index = ih->rptr >> 2;
 	uint32_t dw[8];

 	dw[0] = le32_to_cpu(ih->ring[ring_index + 0]);
 	dw[1] = le32_to_cpu(ih->ring[ring_index + 1]);
 	dw[2] = le32_to_cpu(ih->ring[ring_index + 2]);
 	dw[3] = le32_to_cpu(ih->ring[ring_index + 3]);
 	dw[4] = le32_to_cpu(ih->ring[ring_index + 4]);
 	dw[5] = le32_to_cpu(ih->ring[ring_index + 5]);
 	dw[6] = le32_to_cpu(ih->ring[ring_index + 6]);
 	dw[7] = le32_to_cpu(ih->ring[ring_index + 7]);

 	entry->client_id = dw[0] & 0xff;
 	entry->src_id = (dw[0] >> 8) & 0xff;
 	entry->ring_id = (dw[0] >> 16) & 0xff;
 	entry->vmid = (dw[0] >> 24) & 0xf;
 	entry->vmid_src = (dw[0] >> 31);
 	entry->timestamp = dw[1] | ((u64)(dw[2] & 0xffff) << 32);
 	entry->timestamp_src = dw[2] >> 31;
 	entry->pasid = dw[3] & 0xffff;
 	entry->pasid_src = dw[3] >> 31;
 	entry->src_data[0] = dw[4];
 	entry->src_data[1] = dw[5];
 	entry->src_data[2] = dw[6];
 	entry->src_data[3] = dw[7];

 	/* wptr/rptr are in bytes! */
 	ih->rptr += 32;
 }
	/*
	* Copyright 2014 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.
	*
	*/

	#include <linux/dma-mapping.h>

	#include "amdgpu.h"
	#include "amdgpu_ih.h"

	/**
	* amdgpu_ih_ring_init - initialize the IH state
	*
	* @adev: amdgpu_device pointer
	* @ih: ih ring to initialize
	* @ring_size: ring size to allocate
	* @use_bus_addr: true when we can use dma_alloc_coherent
	*
	* Initializes the IH state and allocates a buffer
	* for the IH ring buffer.
	* Returns 0 for success, errors for failure.
	*/
	int amdgpu_ih_ring_init(struct amdgpu_device adev, struct amdgpu_ih_ring ih,
	unsigned ring_size, bool use_bus_addr)
	{
	u32 rb_bufsz;
	int r;

	/* Align ring size */
	rb_bufsz = order_base_2(ring_size / 4);
	ring_size = (1 << rb_bufsz) * 4;
	ih->ring_size = ring_size;
	ih->ptr_mask = ih->ring_size - 1;
	ih->rptr = 0;
	ih->use_bus_addr = use_bus_addr;

	if (use_bus_addr) {
	dma_addr_t dma_addr;

	if (ih->ring)
	return 0;

	/* add 8 bytes for the rptr/wptr shadows and
	* add them to the end of the ring allocation.
	*/
	ih->ring = dma_alloc_coherent(adev->dev, ih->ring_size + 8,
	&dma_addr, GFP_KERNEL);
	if (ih->ring == NULL)
	return -ENOMEM;

	ih->gpu_addr = dma_addr;
	ih->wptr_addr = dma_addr + ih->ring_size;
	ih->wptr_cpu = &ih->ring[ih->ring_size / 4];
	ih->rptr_addr = dma_addr + ih->ring_size + 4;
	ih->rptr_cpu = &ih->ring[(ih->ring_size / 4) + 1];
	} else {
	unsigned wptr_offs, rptr_offs;

	r = amdgpu_device_wb_get(adev, &wptr_offs);
	if (r)
	return r;

	r = amdgpu_device_wb_get(adev, &rptr_offs);
	if (r) {
	amdgpu_device_wb_free(adev, wptr_offs);
	return r;
	}

	r = amdgpu_bo_create_kernel(adev, ih->ring_size, PAGE_SIZE,
	AMDGPU_GEM_DOMAIN_GTT,
	&ih->ring_obj, &ih->gpu_addr,
	(void **)&ih->ring);
	if (r) {
	amdgpu_device_wb_free(adev, rptr_offs);
	amdgpu_device_wb_free(adev, wptr_offs);
	return r;
	}

	ih->wptr_addr = adev->wb.gpu_addr + wptr_offs * 4;
	ih->wptr_cpu = &adev->wb.wb[wptr_offs];
	ih->rptr_addr = adev->wb.gpu_addr + rptr_offs * 4;
	ih->rptr_cpu = &adev->wb.wb[rptr_offs];
	}

	init_waitqueue_head(&ih->wait_process);
	return 0;
	}

	/**
	* amdgpu_ih_ring_fini - tear down the IH state
	*
	* @adev: amdgpu_device pointer
	* @ih: ih ring to tear down
	*
	* Tears down the IH state and frees buffer
	* used for the IH ring buffer.
	*/
	void amdgpu_ih_ring_fini(struct amdgpu_device adev, struct amdgpu_ih_ring ih)
	{

	if (!ih->ring)
	return;

	if (ih->use_bus_addr) {

	/* add 8 bytes for the rptr/wptr shadows and
	* add them to the end of the ring allocation.
	*/
	dma_free_coherent(adev->dev, ih->ring_size + 8,
	(void *)ih->ring, ih->gpu_addr);
	ih->ring = NULL;
	} else {
	amdgpu_bo_free_kernel(&ih->ring_obj, &ih->gpu_addr,
	(void **)&ih->ring);
	amdgpu_device_wb_free(adev, (ih->wptr_addr - ih->gpu_addr) / 4);
	amdgpu_device_wb_free(adev, (ih->rptr_addr - ih->gpu_addr) / 4);
	}
	}

	/**
	* amdgpu_ih_ring_write - write IV to the ring buffer
	*
	* @ih: ih ring to write to
	* @iv: the iv to write
	* @num_dw: size of the iv in dw
	*
	* Writes an IV to the ring buffer using the CPU and increment the wptr.
	* Used for testing and delegating IVs to a software ring.
	*/
	void amdgpu_ih_ring_write(struct amdgpu_ih_ring ih, const uint32_t iv,
	unsigned int num_dw)
	{
	uint32_t wptr = le32_to_cpu(*ih->wptr_cpu) >> 2;
	unsigned int i;

	for (i = 0; i < num_dw; ++i)
	ih->ring[wptr++] = cpu_to_le32(iv[i]);

	wptr <<= 2;
	wptr &= ih->ptr_mask;

	/* Only commit the new wptr if we don't overflow */
	if (wptr != READ_ONCE(ih->rptr)) {
	wmb();
	WRITE_ONCE(*ih->wptr_cpu, cpu_to_le32(wptr));
	}
	}

	/* Waiter helper that checks current rptr matches or passes checkpoint wptr */
	static bool amdgpu_ih_has_checkpoint_processed(struct amdgpu_device *adev,
	struct amdgpu_ih_ring *ih,
	uint32_t checkpoint_wptr,
	uint32_t *prev_rptr)
	{
	uint32_t cur_rptr = ih->rptr \| (*prev_rptr & ~ih->ptr_mask);

	/* rptr has wrapped. */
	if (cur_rptr < *prev_rptr)
	cur_rptr += ih->ptr_mask + 1;
	*prev_rptr = cur_rptr;

	/* check ring is empty to workaround missing wptr overflow flag */
	return cur_rptr >= checkpoint_wptr \|\|
	(cur_rptr & ih->ptr_mask) == amdgpu_ih_get_wptr(adev, ih);
	}

	/**
	* amdgpu_ih_wait_on_checkpoint_process - wait to process IVs up to checkpoint
	*
	* @adev: amdgpu_device pointer
	* @ih: ih ring to process
	*
	* Used to ensure ring has processed IVs up to the checkpoint write pointer.
	*/
	int amdgpu_ih_wait_on_checkpoint_process(struct amdgpu_device *adev,
	struct amdgpu_ih_ring *ih)
	{
	uint32_t checkpoint_wptr, rptr;

	if (!ih->enabled \|\| adev->shutdown)
	return -ENODEV;

	checkpoint_wptr = amdgpu_ih_get_wptr(adev, ih);
	/* Order wptr with rptr. */
	rmb();
	rptr = READ_ONCE(ih->rptr);

	/* wptr has wrapped. */
	if (rptr > checkpoint_wptr)
	checkpoint_wptr += ih->ptr_mask + 1;

	return wait_event_interruptible(ih->wait_process,
	amdgpu_ih_has_checkpoint_processed(adev, ih,
	checkpoint_wptr, &rptr));
	}

	/**
	* amdgpu_ih_process - interrupt handler
	*
	* @adev: amdgpu_device pointer
	* @ih: ih ring to process
	*
	* Interrupt hander (VI), walk the IH ring.
	* Returns irq process return code.
	*/
	int amdgpu_ih_process(struct amdgpu_device adev, struct amdgpu_ih_ring ih)
	{
	unsigned int count;
	u32 wptr;

	if (!ih->enabled \|\| adev->shutdown)
	return IRQ_NONE;

	wptr = amdgpu_ih_get_wptr(adev, ih);

	restart_ih:
	count = AMDGPU_IH_MAX_NUM_IVS;
	DRM_DEBUG("%s: rptr %d, wptr %d\n", __func__, ih->rptr, wptr);

	/* Order reading of wptr vs. reading of IH ring data */
	rmb();

	while (ih->rptr != wptr && --count) {
	amdgpu_irq_dispatch(adev, ih);
	ih->rptr &= ih->ptr_mask;
	}

	amdgpu_ih_set_rptr(adev, ih);
	wake_up_all(&ih->wait_process);

	/* make sure wptr hasn't changed while processing */
	wptr = amdgpu_ih_get_wptr(adev, ih);
	if (wptr != ih->rptr)
	goto restart_ih;

	return IRQ_HANDLED;
	}

	/**
	* amdgpu_ih_decode_iv_helper - decode an interrupt vector
	*
	* @adev: amdgpu_device pointer
	* @ih: ih ring to process
	* @entry: IV entry
	*
	* Decodes the interrupt vector at the current rptr
	* position and also advance the position for for Vega10
	* and later GPUs.
	*/
	void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
	struct amdgpu_ih_ring *ih,
	struct amdgpu_iv_entry *entry)
	{
	/* wptr/rptr are in bytes! */
	u32 ring_index = ih->rptr >> 2;
	uint32_t dw[8];

	dw[0] = le32_to_cpu(ih->ring[ring_index + 0]);
	dw[1] = le32_to_cpu(ih->ring[ring_index + 1]);
	dw[2] = le32_to_cpu(ih->ring[ring_index + 2]);
	dw[3] = le32_to_cpu(ih->ring[ring_index + 3]);
	dw[4] = le32_to_cpu(ih->ring[ring_index + 4]);
	dw[5] = le32_to_cpu(ih->ring[ring_index + 5]);
	dw[6] = le32_to_cpu(ih->ring[ring_index + 6]);
	dw[7] = le32_to_cpu(ih->ring[ring_index + 7]);

	entry->client_id = dw[0] & 0xff;
	entry->src_id = (dw[0] >> 8) & 0xff;
	entry->ring_id = (dw[0] >> 16) & 0xff;
	entry->vmid = (dw[0] >> 24) & 0xf;
	entry->vmid_src = (dw[0] >> 31);
	entry->timestamp = dw[1] \| ((u64)(dw[2] & 0xffff) << 32);
	entry->timestamp_src = dw[2] >> 31;
	entry->pasid = dw[3] & 0xffff;
	entry->pasid_src = dw[3] >> 31;
	entry->src_data[0] = dw[4];
	entry->src_data[1] = dw[5];
	entry->src_data[2] = dw[6];
	entry->src_data[3] = dw[7];

	/* wptr/rptr are in bytes! */
	ih->rptr += 32;
	}