kolibrios/drivers/video/drm/radeon/radeon_cs.c

/*
 * Copyright 2008 Jerome Glisse.
 * All Rights Reserved.
 *
 * 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 (including the next
 * paragraph) 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
 * PRECISION INSIGHT AND/OR ITS SUPPLIERS 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:
 *    Jerome Glisse <glisse@freedesktop.org>
 */
#include <linux/list_sort.h>
#include <drm/drmP.h>
#include <drm/radeon_drm.h>
#include "radeon_reg.h"
#include "radeon.h"
#include "radeon_trace.h"

#define RADEON_CS_MAX_PRIORITY		32u
#define RADEON_CS_NUM_BUCKETS		(RADEON_CS_MAX_PRIORITY + 1)

/* This is based on the bucket sort with O(n) time complexity.
 * An item with priority "i" is added to bucket[i]. The lists are then
 * concatenated in descending order.
 */
struct radeon_cs_buckets {
	struct list_head bucket[RADEON_CS_NUM_BUCKETS];
};

static void radeon_cs_buckets_init(struct radeon_cs_buckets *b)
{
	unsigned i;

	for (i = 0; i < RADEON_CS_NUM_BUCKETS; i++)
		INIT_LIST_HEAD(&b->bucket[i]);
}

static void radeon_cs_buckets_add(struct radeon_cs_buckets *b,
				  struct list_head *item, unsigned priority)
{
	/* Since buffers which appear sooner in the relocation list are
	 * likely to be used more often than buffers which appear later
	 * in the list, the sort mustn't change the ordering of buffers
	 * with the same priority, i.e. it must be stable.
	 */
	list_add_tail(item, &b->bucket[min(priority, RADEON_CS_MAX_PRIORITY)]);
}

static void radeon_cs_buckets_get_list(struct radeon_cs_buckets *b,
				       struct list_head *out_list)
{
	unsigned i;

	/* Connect the sorted buckets in the output list. */
	for (i = 0; i < RADEON_CS_NUM_BUCKETS; i++) {
		list_splice(&b->bucket[i], out_list);
	}
}

static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
{
	struct drm_device *ddev = p->rdev->ddev;
	struct radeon_cs_chunk *chunk;
	struct radeon_cs_buckets buckets;
	unsigned i;
	bool need_mmap_lock = false;
	int r;

	if (p->chunk_relocs == NULL) {
		return 0;
	}
	chunk = p->chunk_relocs;
	p->dma_reloc_idx = 0;
	/* FIXME: we assume that each relocs use 4 dwords */
	p->nrelocs = chunk->length_dw / 4;
	p->relocs = kcalloc(p->nrelocs, sizeof(struct radeon_bo_list), GFP_KERNEL);
	if (p->relocs == NULL) {
		return -ENOMEM;
	}

	radeon_cs_buckets_init(&buckets);

	for (i = 0; i < p->nrelocs; i++) {
		struct drm_radeon_cs_reloc *r;
		struct drm_gem_object *gobj;
		unsigned priority;

		r = (struct drm_radeon_cs_reloc *)&chunk->kdata[i*4];
		gobj = drm_gem_object_lookup(ddev, p->filp, r->handle);
		if (gobj == NULL) {
			DRM_ERROR("gem object lookup failed 0x%x\n",
				  r->handle);
			return -ENOENT;
		}
		p->relocs[i].robj = gem_to_radeon_bo(gobj);

		/* The userspace buffer priorities are from 0 to 15. A higher
		 * number means the buffer is more important.
		 * Also, the buffers used for write have a higher priority than
		 * the buffers used for read only, which doubles the range
		 * to 0 to 31. 32 is reserved for the kernel driver.
		 */
		priority = (r->flags & RADEON_RELOC_PRIO_MASK) * 2
			   + !!r->write_domain;

		/* the first reloc of an UVD job is the msg and that must be in
		   VRAM, also but everything into VRAM on AGP cards and older
		   IGP chips to avoid image corruptions */
		if (p->ring == R600_RING_TYPE_UVD_INDEX &&
		    (i == 0 || drm_pci_device_is_agp(p->rdev->ddev) ||
		     p->rdev->family == CHIP_RS780 ||
		     p->rdev->family == CHIP_RS880)) {

			/* TODO: is this still needed for NI+ ? */
			p->relocs[i].prefered_domains =
				RADEON_GEM_DOMAIN_VRAM;

			p->relocs[i].allowed_domains =
				RADEON_GEM_DOMAIN_VRAM;

			/* prioritize this over any other relocation */
			priority = RADEON_CS_MAX_PRIORITY;
		} else {
			uint32_t domain = r->write_domain ?
				r->write_domain : r->read_domains;

			if (domain & RADEON_GEM_DOMAIN_CPU) {
				DRM_ERROR("RADEON_GEM_DOMAIN_CPU is not valid "
					  "for command submission\n");
				return -EINVAL;
			}

			p->relocs[i].prefered_domains = domain;
			if (domain == RADEON_GEM_DOMAIN_VRAM)
				domain |= RADEON_GEM_DOMAIN_GTT;
			p->relocs[i].allowed_domains = domain;
		}
/*
		if (radeon_ttm_tt_has_userptr(p->relocs[i].robj->tbo.ttm)) {
			uint32_t domain = p->relocs[i].prefered_domains;
			if (!(domain & RADEON_GEM_DOMAIN_GTT)) {
				DRM_ERROR("Only RADEON_GEM_DOMAIN_GTT is "
					  "allowed for userptr BOs\n");
				return -EINVAL;
			}
			need_mmap_lock = true;
			domain = RADEON_GEM_DOMAIN_GTT;
			p->relocs[i].prefered_domains = domain;
			p->relocs[i].allowed_domains = domain;
		}
*/
		p->relocs[i].tv.bo = &p->relocs[i].robj->tbo;
		p->relocs[i].tv.shared = !r->write_domain;

		radeon_cs_buckets_add(&buckets, &p->relocs[i].tv.head,
				      priority);
	}

	radeon_cs_buckets_get_list(&buckets, &p->validated);

	if (p->cs_flags & RADEON_CS_USE_VM)
		p->vm_bos = radeon_vm_get_bos(p->rdev, p->ib.vm,
					      &p->validated);

	r = radeon_bo_list_validate(p->rdev, &p->ticket, &p->validated, p->ring);

	return r;
}

static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority)
{
	p->priority = priority;

	switch (ring) {
	default:
		DRM_ERROR("unknown ring id: %d\n", ring);
		return -EINVAL;
	case RADEON_CS_RING_GFX:
		p->ring = RADEON_RING_TYPE_GFX_INDEX;
		break;
	case RADEON_CS_RING_COMPUTE:
		if (p->rdev->family >= CHIP_TAHITI) {
			if (p->priority > 0)
				p->ring = CAYMAN_RING_TYPE_CP1_INDEX;
			else
				p->ring = CAYMAN_RING_TYPE_CP2_INDEX;
		} else
			p->ring = RADEON_RING_TYPE_GFX_INDEX;
		break;
	case RADEON_CS_RING_DMA:
		if (p->rdev->family >= CHIP_CAYMAN) {
			if (p->priority > 0)
				p->ring = R600_RING_TYPE_DMA_INDEX;
			else
				p->ring = CAYMAN_RING_TYPE_DMA1_INDEX;
		} else if (p->rdev->family >= CHIP_RV770) {
			p->ring = R600_RING_TYPE_DMA_INDEX;
		} else {
			return -EINVAL;
		}
		break;
	case RADEON_CS_RING_UVD:
		p->ring = R600_RING_TYPE_UVD_INDEX;
		break;
	case RADEON_CS_RING_VCE:
		/* TODO: only use the low priority ring for now */
		p->ring = TN_RING_TYPE_VCE1_INDEX;
		break;
	}
	return 0;
}

static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
{
	struct radeon_bo_list *reloc;
	int r;

	list_for_each_entry(reloc, &p->validated, tv.head) {
		struct reservation_object *resv;

		resv = reloc->robj->tbo.resv;
		r = radeon_sync_resv(p->rdev, &p->ib.sync, resv,
				     reloc->tv.shared);
		if (r)
			return r;
	}
	return 0;
}

/* XXX: note that this is called from the legacy UMS CS ioctl as well */
int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
{
	struct drm_radeon_cs *cs = data;
	uint64_t *chunk_array_ptr;
	unsigned size, i;
	u32 ring = RADEON_CS_RING_GFX;
	s32 priority = 0;

	INIT_LIST_HEAD(&p->validated);

	if (!cs->num_chunks) {
		return 0;
	}

	/* get chunks */
	p->idx = 0;
	p->ib.sa_bo = NULL;
	p->const_ib.sa_bo = NULL;
	p->chunk_ib = NULL;
	p->chunk_relocs = NULL;
	p->chunk_flags = NULL;
	p->chunk_const_ib = NULL;
	p->chunks_array = kcalloc(cs->num_chunks, sizeof(uint64_t), GFP_KERNEL);
	if (p->chunks_array == NULL) {
		return -ENOMEM;
	}
	chunk_array_ptr = (uint64_t *)(unsigned long)(cs->chunks);
	if (copy_from_user(p->chunks_array, chunk_array_ptr,
			       sizeof(uint64_t)*cs->num_chunks)) {
		return -EFAULT;
	}
	p->cs_flags = 0;
	p->nchunks = cs->num_chunks;
	p->chunks = kcalloc(p->nchunks, sizeof(struct radeon_cs_chunk), GFP_KERNEL);
	if (p->chunks == NULL) {
		return -ENOMEM;
	}
	for (i = 0; i < p->nchunks; i++) {
		struct drm_radeon_cs_chunk __user **chunk_ptr = NULL;
		struct drm_radeon_cs_chunk user_chunk;
		uint32_t __user *cdata;

		chunk_ptr = (void __user*)(unsigned long)p->chunks_array[i];
		if (copy_from_user(&user_chunk, chunk_ptr,
				       sizeof(struct drm_radeon_cs_chunk))) {
			return -EFAULT;
		}
		p->chunks[i].length_dw = user_chunk.length_dw;
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_RELOCS) {
			p->chunk_relocs = &p->chunks[i];
		}
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_IB) {
			p->chunk_ib = &p->chunks[i];
			/* zero length IB isn't useful */
			if (p->chunks[i].length_dw == 0)
				return -EINVAL;
		}
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_CONST_IB) {
			p->chunk_const_ib = &p->chunks[i];
			/* zero length CONST IB isn't useful */
			if (p->chunks[i].length_dw == 0)
				return -EINVAL;
		}
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_FLAGS) {
			p->chunk_flags = &p->chunks[i];
			/* zero length flags aren't useful */
			if (p->chunks[i].length_dw == 0)
				return -EINVAL;
		}

		size = p->chunks[i].length_dw;
		cdata = (void __user *)(unsigned long)user_chunk.chunk_data;
		p->chunks[i].user_ptr = cdata;
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_CONST_IB)
			continue;

		if (user_chunk.chunk_id == RADEON_CHUNK_ID_IB) {
			if (!p->rdev || !(p->rdev->flags & RADEON_IS_AGP))
				continue;
		}

		p->chunks[i].kdata = drm_malloc_ab(size, sizeof(uint32_t));
		size *= sizeof(uint32_t);
		if (p->chunks[i].kdata == NULL) {
			return -ENOMEM;
		}
		if (copy_from_user(p->chunks[i].kdata, cdata, size)) {
			return -EFAULT;
		}
		if (user_chunk.chunk_id == RADEON_CHUNK_ID_FLAGS) {
			p->cs_flags = p->chunks[i].kdata[0];
			if (p->chunks[i].length_dw > 1)
				ring = p->chunks[i].kdata[1];
			if (p->chunks[i].length_dw > 2)
				priority = (s32)p->chunks[i].kdata[2];
		}
	}

	/* these are KMS only */
	if (p->rdev) {
		if ((p->cs_flags & RADEON_CS_USE_VM) &&
		    !p->rdev->vm_manager.enabled) {
			DRM_ERROR("VM not active on asic!\n");
			return -EINVAL;
		}

		if (radeon_cs_get_ring(p, ring, priority))
			return -EINVAL;

		/* we only support VM on some SI+ rings */
		if ((p->cs_flags & RADEON_CS_USE_VM) == 0) {
			if (p->rdev->asic->ring[p->ring]->cs_parse == NULL) {
				DRM_ERROR("Ring %d requires VM!\n", p->ring);
				return -EINVAL;
			}
		} else {
			if (p->rdev->asic->ring[p->ring]->ib_parse == NULL) {
				DRM_ERROR("VM not supported on ring %d!\n",
					  p->ring);
				return -EINVAL;
			}
		}
	}

	return 0;
}

static int cmp_size_smaller_first(void *priv, struct list_head *a,
				  struct list_head *b)
{
	struct radeon_bo_list *la = list_entry(a, struct radeon_bo_list, tv.head);
	struct radeon_bo_list *lb = list_entry(b, struct radeon_bo_list, tv.head);

	/* Sort A before B if A is smaller. */
	return (int)la->robj->tbo.num_pages - (int)lb->robj->tbo.num_pages;
}

/**
 * cs_parser_fini() - clean parser states
 * @parser:	parser structure holding parsing context.
 * @error:	error number
 *
 * If error is set than unvalidate buffer, otherwise just free memory
 * used by parsing context.
 **/
static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error, bool backoff)
{
	unsigned i;

	if (!error) {
		/* Sort the buffer list from the smallest to largest buffer,
		 * which affects the order of buffers in the LRU list.
		 * This assures that the smallest buffers are added first
		 * to the LRU list, so they are likely to be later evicted
		 * first, instead of large buffers whose eviction is more
		 * expensive.
		 *
		 * This slightly lowers the number of bytes moved by TTM
		 * per frame under memory pressure.
		 */
		list_sort(NULL, &parser->validated, cmp_size_smaller_first);

		ttm_eu_fence_buffer_objects(&parser->ticket,
					    &parser->validated,
					    &parser->ib.fence->base);
	} else if (backoff) {
		ttm_eu_backoff_reservation(&parser->ticket,
					   &parser->validated);
	}

	if (parser->relocs != NULL) {
		for (i = 0; i < parser->nrelocs; i++) {
			struct radeon_bo *bo = parser->relocs[i].robj;
			if (bo == NULL)
				continue;

			drm_gem_object_unreference_unlocked(&bo->gem_base);
		}
	}
	kfree(parser->track);
	kfree(parser->relocs);
	drm_free_large(parser->vm_bos);
	for (i = 0; i < parser->nchunks; i++)
		drm_free_large(parser->chunks[i].kdata);
	kfree(parser->chunks);
	kfree(parser->chunks_array);
	radeon_ib_free(parser->rdev, &parser->ib);
	radeon_ib_free(parser->rdev, &parser->const_ib);
}

static int radeon_cs_ib_chunk(struct radeon_device *rdev,
			      struct radeon_cs_parser *parser)
{
	int r;

	if (parser->chunk_ib == NULL)
		return 0;

	if (parser->cs_flags & RADEON_CS_USE_VM)
		return 0;

	r = radeon_cs_parse(rdev, parser->ring, parser);
	if (r || parser->parser_error) {
		DRM_ERROR("Invalid command stream !\n");
		return r;
	}

	r = radeon_cs_sync_rings(parser);
	if (r) {
		if (r != -ERESTARTSYS)
			DRM_ERROR("Failed to sync rings: %i\n", r);
		return r;
	}

	if (parser->ring == R600_RING_TYPE_UVD_INDEX)
		radeon_uvd_note_usage(rdev);
	else if ((parser->ring == TN_RING_TYPE_VCE1_INDEX) ||
		 (parser->ring == TN_RING_TYPE_VCE2_INDEX))
		radeon_vce_note_usage(rdev);

	r = radeon_ib_schedule(rdev, &parser->ib, NULL, true);
	if (r) {
		DRM_ERROR("Failed to schedule IB !\n");
	}
	return r;
}

static int radeon_bo_vm_update_pte(struct radeon_cs_parser *p,
				   struct radeon_vm *vm)
{
	struct radeon_device *rdev = p->rdev;
	struct radeon_bo_va *bo_va;
	int i, r;

	r = radeon_vm_update_page_directory(rdev, vm);
	if (r)
		return r;

	r = radeon_vm_clear_freed(rdev, vm);
	if (r)
		return r;

	if (vm->ib_bo_va == NULL) {
		DRM_ERROR("Tmp BO not in VM!\n");
		return -EINVAL;
	}

	r = radeon_vm_bo_update(rdev, vm->ib_bo_va,
				&rdev->ring_tmp_bo.bo->tbo.mem);
	if (r)
		return r;

	for (i = 0; i < p->nrelocs; i++) {
		struct radeon_bo *bo;

		bo = p->relocs[i].robj;
		bo_va = radeon_vm_bo_find(vm, bo);
		if (bo_va == NULL) {
			dev_err(rdev->dev, "bo %p not in vm %p\n", bo, vm);
			return -EINVAL;
		}

		r = radeon_vm_bo_update(rdev, bo_va, &bo->tbo.mem);
		if (r)
			return r;

		radeon_sync_fence(&p->ib.sync, bo_va->last_pt_update);
	}

	return radeon_vm_clear_invalids(rdev, vm);
}

static int radeon_cs_ib_vm_chunk(struct radeon_device *rdev,
				 struct radeon_cs_parser *parser)
{
	struct radeon_fpriv *fpriv = parser->filp->driver_priv;
	struct radeon_vm *vm = &fpriv->vm;
	int r;

	if (parser->chunk_ib == NULL)
		return 0;
	if ((parser->cs_flags & RADEON_CS_USE_VM) == 0)
		return 0;

	if (parser->const_ib.length_dw) {
		r = radeon_ring_ib_parse(rdev, parser->ring, &parser->const_ib);
		if (r) {
			return r;
		}
	}

	r = radeon_ring_ib_parse(rdev, parser->ring, &parser->ib);
	if (r) {
		return r;
	}

	if (parser->ring == R600_RING_TYPE_UVD_INDEX)
		radeon_uvd_note_usage(rdev);

	mutex_lock(&vm->mutex);
	r = radeon_bo_vm_update_pte(parser, vm);
	if (r) {
		goto out;
	}

	r = radeon_cs_sync_rings(parser);
	if (r) {
		if (r != -ERESTARTSYS)
			DRM_ERROR("Failed to sync rings: %i\n", r);
		goto out;
	}

	if ((rdev->family >= CHIP_TAHITI) &&
	    (parser->chunk_const_ib != NULL)) {
		r = radeon_ib_schedule(rdev, &parser->ib, &parser->const_ib, true);
	} else {
		r = radeon_ib_schedule(rdev, &parser->ib, NULL, true);
	}

out:
	mutex_unlock(&vm->mutex);
	return r;
}

static int radeon_cs_handle_lockup(struct radeon_device *rdev, int r)
{
	if (r == -EDEADLK) {
		r = radeon_gpu_reset(rdev);
		if (!r)
			r = -EAGAIN;
	}
	return r;
}

static int radeon_cs_ib_fill(struct radeon_device *rdev, struct radeon_cs_parser *parser)
{
	struct radeon_cs_chunk *ib_chunk;
	struct radeon_vm *vm = NULL;
	int r;

	if (parser->chunk_ib == NULL)
		return 0;

	if (parser->cs_flags & RADEON_CS_USE_VM) {
		struct radeon_fpriv *fpriv = parser->filp->driver_priv;
		vm = &fpriv->vm;

		if ((rdev->family >= CHIP_TAHITI) &&
		    (parser->chunk_const_ib != NULL)) {
			ib_chunk = parser->chunk_const_ib;
			if (ib_chunk->length_dw > RADEON_IB_VM_MAX_SIZE) {
				DRM_ERROR("cs IB CONST too big: %d\n", ib_chunk->length_dw);
				return -EINVAL;
			}
			r =  radeon_ib_get(rdev, parser->ring, &parser->const_ib,
					   vm, ib_chunk->length_dw * 4);
			if (r) {
				DRM_ERROR("Failed to get const ib !\n");
				return r;
			}
			parser->const_ib.is_const_ib = true;
			parser->const_ib.length_dw = ib_chunk->length_dw;
			if (copy_from_user(parser->const_ib.ptr,
					       ib_chunk->user_ptr,
					       ib_chunk->length_dw * 4))
				return -EFAULT;
		}

		ib_chunk = parser->chunk_ib;
		if (ib_chunk->length_dw > RADEON_IB_VM_MAX_SIZE) {
			DRM_ERROR("cs IB too big: %d\n", ib_chunk->length_dw);
			return -EINVAL;
		}
	}
	ib_chunk = parser->chunk_ib;

	r =  radeon_ib_get(rdev, parser->ring, &parser->ib,
			   vm, ib_chunk->length_dw * 4);
	if (r) {
		DRM_ERROR("Failed to get ib !\n");
		return r;
	}
	parser->ib.length_dw = ib_chunk->length_dw;
	if (ib_chunk->kdata)
		memcpy(parser->ib.ptr, ib_chunk->kdata, ib_chunk->length_dw * 4);
	else if (copy_from_user(parser->ib.ptr, ib_chunk->user_ptr, ib_chunk->length_dw * 4))
		return -EFAULT;
	return 0;
}

int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
{
	struct radeon_device *rdev = dev->dev_private;
	struct radeon_cs_parser parser;
	int r;

	down_read(&rdev->exclusive_lock);
	if (!rdev->accel_working) {
		up_read(&rdev->exclusive_lock);
		return -EBUSY;
	}
	/* initialize parser */
	memset(&parser, 0, sizeof(struct radeon_cs_parser));
	parser.filp = filp;
	parser.rdev = rdev;
	parser.dev = rdev->dev;
	parser.family = rdev->family;
	r = radeon_cs_parser_init(&parser, data);
	if (r) {
		DRM_ERROR("Failed to initialize parser !\n");
		radeon_cs_parser_fini(&parser, r, false);
		up_read(&rdev->exclusive_lock);
		r = radeon_cs_handle_lockup(rdev, r);
		return r;
	}

	r = radeon_cs_ib_fill(rdev, &parser);
	if (!r) {
		r = radeon_cs_parser_relocs(&parser);
		if (r && r != -ERESTARTSYS)
			DRM_ERROR("Failed to parse relocation %d!\n", r);
	}

	if (r) {
		radeon_cs_parser_fini(&parser, r, false);
		up_read(&rdev->exclusive_lock);
		r = radeon_cs_handle_lockup(rdev, r);
		return r;
	}

	trace_radeon_cs(&parser);

	r = radeon_cs_ib_chunk(rdev, &parser);
	if (r) {
		goto out;
	}
	r = radeon_cs_ib_vm_chunk(rdev, &parser);
	if (r) {
		goto out;
	}
out:
	radeon_cs_parser_fini(&parser, r, true);
	up_read(&rdev->exclusive_lock);
	r = radeon_cs_handle_lockup(rdev, r);
	return r;
}

/**
 * radeon_cs_packet_parse() - parse cp packet and point ib index to next packet
 * @parser:	parser structure holding parsing context.
 * @pkt:	where to store packet information
 *
 * Assume that chunk_ib_index is properly set. Will return -EINVAL
 * if packet is bigger than remaining ib size. or if packets is unknown.
 **/
int radeon_cs_packet_parse(struct radeon_cs_parser *p,
			   struct radeon_cs_packet *pkt,
			   unsigned idx)
{
	struct radeon_cs_chunk *ib_chunk = p->chunk_ib;
	struct radeon_device *rdev = p->rdev;
	uint32_t header;
	int ret = 0, i;

	if (idx >= ib_chunk->length_dw) {
		DRM_ERROR("Can not parse packet at %d after CS end %d !\n",
			  idx, ib_chunk->length_dw);
		return -EINVAL;
	}
	header = radeon_get_ib_value(p, idx);
	pkt->idx = idx;
	pkt->type = RADEON_CP_PACKET_GET_TYPE(header);
	pkt->count = RADEON_CP_PACKET_GET_COUNT(header);
	pkt->one_reg_wr = 0;
	switch (pkt->type) {
	case RADEON_PACKET_TYPE0:
		if (rdev->family < CHIP_R600) {
			pkt->reg = R100_CP_PACKET0_GET_REG(header);
			pkt->one_reg_wr =
				RADEON_CP_PACKET0_GET_ONE_REG_WR(header);
		} else
			pkt->reg = R600_CP_PACKET0_GET_REG(header);
		break;
	case RADEON_PACKET_TYPE3:
		pkt->opcode = RADEON_CP_PACKET3_GET_OPCODE(header);
		break;
	case RADEON_PACKET_TYPE2:
		pkt->count = -1;
		break;
	default:
		DRM_ERROR("Unknown packet type %d at %d !\n", pkt->type, idx);
		ret = -EINVAL;
		goto dump_ib;
	}
	if ((pkt->count + 1 + pkt->idx) >= ib_chunk->length_dw) {
		DRM_ERROR("Packet (%d:%d:%d) end after CS buffer (%d) !\n",
			  pkt->idx, pkt->type, pkt->count, ib_chunk->length_dw);
		ret = -EINVAL;
		goto dump_ib;
	}
	return 0;

dump_ib:
	for (i = 0; i < ib_chunk->length_dw; i++) {
		if (i == idx)
			printk("\t0x%08x <---\n", radeon_get_ib_value(p, i));
		else
			printk("\t0x%08x\n", radeon_get_ib_value(p, i));
	}
	return ret;
}

/**
 * radeon_cs_packet_next_is_pkt3_nop() - test if the next packet is P3 NOP
 * @p:		structure holding the parser context.
 *
 * Check if the next packet is NOP relocation packet3.
 **/
bool radeon_cs_packet_next_is_pkt3_nop(struct radeon_cs_parser *p)
{
	struct radeon_cs_packet p3reloc;
	int r;

	r = radeon_cs_packet_parse(p, &p3reloc, p->idx);
	if (r)
		return false;
	if (p3reloc.type != RADEON_PACKET_TYPE3)
		return false;
	if (p3reloc.opcode != RADEON_PACKET3_NOP)
		return false;
	return true;
}

/**
 * radeon_cs_dump_packet() - dump raw packet context
 * @p:		structure holding the parser context.
 * @pkt:	structure holding the packet.
 *
 * Used mostly for debugging and error reporting.
 **/
void radeon_cs_dump_packet(struct radeon_cs_parser *p,
			   struct radeon_cs_packet *pkt)
{
	volatile uint32_t *ib;
	unsigned i;
	unsigned idx;

	ib = p->ib.ptr;
	idx = pkt->idx;
	for (i = 0; i <= (pkt->count + 1); i++, idx++)
		DRM_INFO("ib[%d]=0x%08X\n", idx, ib[idx]);
}

/**
 * radeon_cs_packet_next_reloc() - parse next (should be reloc) packet
 * @parser:		parser structure holding parsing context.
 * @data:		pointer to relocation data
 * @offset_start:	starting offset
 * @offset_mask:	offset mask (to align start offset on)
 * @reloc:		reloc informations
 *
 * Check if next packet is relocation packet3, do bo validation and compute
 * GPU offset using the provided start.
 **/
int radeon_cs_packet_next_reloc(struct radeon_cs_parser *p,
				struct radeon_bo_list **cs_reloc,
				int nomm)
{
	struct radeon_cs_chunk *relocs_chunk;
	struct radeon_cs_packet p3reloc;
	unsigned idx;
	int r;

	if (p->chunk_relocs == NULL) {
		DRM_ERROR("No relocation chunk !\n");
		return -EINVAL;
	}
	*cs_reloc = NULL;
	relocs_chunk = p->chunk_relocs;
	r = radeon_cs_packet_parse(p, &p3reloc, p->idx);
	if (r)
		return r;
	p->idx += p3reloc.count + 2;
	if (p3reloc.type != RADEON_PACKET_TYPE3 ||
	    p3reloc.opcode != RADEON_PACKET3_NOP) {
		DRM_ERROR("No packet3 for relocation for packet at %d.\n",
			  p3reloc.idx);
		radeon_cs_dump_packet(p, &p3reloc);
		return -EINVAL;
	}
	idx = radeon_get_ib_value(p, p3reloc.idx + 1);
	if (idx >= relocs_chunk->length_dw) {
		DRM_ERROR("Relocs at %d after relocations chunk end %d !\n",
			  idx, relocs_chunk->length_dw);
		radeon_cs_dump_packet(p, &p3reloc);
		return -EINVAL;
	}
	/* FIXME: we assume reloc size is 4 dwords */
	if (nomm) {
		*cs_reloc = p->relocs;
		(*cs_reloc)->gpu_offset =
			(u64)relocs_chunk->kdata[idx + 3] << 32;
		(*cs_reloc)->gpu_offset |= relocs_chunk->kdata[idx + 0];
	} else
		*cs_reloc = &p->relocs[(idx / 4)];
	return 0;
}