linux-core/drm_bo_move.c


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 * 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
 * VA LINUX SYSTEMS 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.
 */

#ifndef __NOUVEAU_DRM_H__
#define __NOUVEAU_DRM_H__

#define NOUVEAU_DRM_HEADER_PATCHLEVEL 11

struct drm_nouveau_channel_alloc {
	uint32_t     fb_ctxdma_handle;
	uint32_t     tt_ctxdma_handle;

	int          channel;
	uint32_t     put_base;
	/* FIFO control regs */
	drm_handle_t ctrl;
	int          ctrl_size;
	/* DMA command buffer */
	drm_handle_t cmdbuf;
	int          cmdbuf_size;
	/* Notifier memory */
	drm_handle_t notifier;
	int          notifier_size;
};

struct drm_nouveau_channel_free {
	int channel;
};

struct drm_nouveau_grobj_alloc {
	int      channel;
	uint32_t handle;
	int      class;
};

#define NOUVEAU_MEM_ACCESS_RO	1
#define NOUVEAU_MEM_ACCESS_WO	2
#define NOUVEAU_MEM_ACCESS_RW	3
struct drm_nouveau_notifierobj_alloc {
	int      channel;
	uint32_t handle;
	int      count;

	uint32_t offset;
};

struct drm_nouveau_gpuobj_free {
	int      channel;
	uint32_t handle;
};

/* This is needed to avoid a race condition.
 * Otherwise you may be writing in the fetch area.
 * Is this large enough, as it's only 32 bytes, and the maximum fetch size is 256 bytes?
 */
#define NOUVEAU_DMA_SKIPS 8

#define NOUVEAU_MEM_FB			0x00000001
#define NOUVEAU_MEM_AGP			0x00000002
#define NOUVEAU_MEM_FB_ACCEPTABLE	0x00000004
#define NOUVEAU_MEM_AGP_ACCEPTABLE	0x00000008
#define NOUVEAU_MEM_PCI			0x00000010
#define NOUVEAU_MEM_PCI_ACCEPTABLE	0x00000020
#define NOUVEAU_MEM_PINNED		0x00000040
#define NOUVEAU_MEM_USER_BACKED		0x00000080
#define NOUVEAU_MEM_MAPPED		0x00000100
#define NOUVEAU_MEM_TILE		0x00000200
#define NOUVEAU_MEM_TILE_ZETA		0x00000400
#define NOUVEAU_MEM_INSTANCE		0x01000000 /* internal */
#define NOUVEAU_MEM_NOTIFIER            0x02000000 /* internal */
#define NOUVEAU_MEM_NOVM		0x04000000 /* internal */
#define NOUVEAU_MEM_USER		0x08000000 /* internal */
#define NOUVEAU_MEM_INTERNAL (NOUVEAU_MEM_INSTANCE | \
			      NOUVEAU_MEM_NOTIFIER | \
			      NOUVEAU_MEM_NOVM | \
			      NOUVEAU_MEM_USER)

struct drm_nouveau_mem_alloc {
	int flags;
	int alignment;
	uint64_t size;	// in bytes
	uint64_t offset;
	drm_handle_t map_handle;
};

struct drm_nouveau_mem_free {
	uint64_t offset;
	int flags;
};

struct drm_nouveau_mem_tile {
	uint64_t offset;
	uint64_t delta;
	uint64_t size;
	int flags;
};

/* FIXME : maybe unify {GET,SET}PARAMs */
#define NOUVEAU_GETPARAM_PCI_VENDOR      3
#define NOUVEAU_GETPARAM_PCI_DEVICE      4
#define NOUVEAU_GETPARAM_BUS_TYPE        5
#define NOUVEAU_GETPARAM_FB_PHYSICAL     6
#define NOUVEAU_GETPARAM_AGP_PHYSICAL    7
#define NOUVEAU_GETPARAM_FB_SIZE         8
#define NOUVEAU_GETPARAM_AGP_SIZE        9
#define NOUVEAU_GETPARAM_PCI_PHYSICAL    10
#define NOUVEAU_GETPARAM_CHIPSET_ID      11
struct drm_nouveau_getparam {
	uint64_t param;
	uint64_t value;
};

#define NOUVEAU_SETPARAM_CMDBUF_LOCATION 1
#define NOUVEAU_SETPARAM_CMDBUF_SIZE     2
struct drm_nouveau_setparam {
	uint64_t param;
	uint64_t value;
};

enum nouveau_card_type {
	NV_UNKNOWN =0,
	NV_04      =4,
	NV_05      =5,
	NV_10      =10,
	NV_11      =11,
	NV_17      =17,
	NV_20      =20,
	NV_30      =30,
	NV_40      =40,
	NV_44      =44,
	NV_50      =50,
	NV_LAST    =0xffff,
};

enum nouveau_bus_type {
	NV_AGP     =0,
	NV_PCI     =1,
	NV_PCIE    =2,
};

#define NOUVEAU_MAX_SAREA_CLIPRECTS 16

struct drm_nouveau_sarea {
	/* the cliprects */
	struct drm_clip_rect boxes[NOUVEAU_MAX_SAREA_CLIPRECTS];
	unsigned int nbox;
};

#define DRM_NOUVEAU_CARD_INIT          0x00
#define DRM_NOUVEAU_GETPARAM           0x01
#define DRM_NOUVEAU_SETPARAM           0x02
#define DRM_NOUVEAU_CHANNEL_ALLOC      0x03
#define DRM_NOUVEAU_CHANNEL_FREE       0x04
#define DRM_NOUVEAU_GROBJ_ALLOC        0x05
#define DRM_NOUVEAU_NOTIFIEROBJ_ALLOC  0x06
#define DRM_NOUVEAU_GPUOBJ_FREE        0x07
#define DRM_NOUVEAU_MEM_ALLOC          0x08
#define DRM_NOUVEAU_MEM_FREE           0x09
#define DRM_NOUVEAU_MEM_TILE           0x0a

#endif /* __NOUVEAU_DRM_H__ */
/**************************************************************************
 *
 * Copyright (c) 2007 Tungsten Graphics, Inc., Cedar Park, TX., USA
 * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS 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: Thomas Hellstr�m <thomas-at-tungstengraphics-dot-com>
 */

#include "drmP.h"

/**
 * Free the old memory node unless it's a pinned region and we
 * have not been requested to free also pinned regions.
 */

static void drm_bo_free_old_node(struct drm_buffer_object *bo)
{
	struct drm_bo_mem_reg *old_mem = &bo->mem;

	if (old_mem->mm_node && (old_mem->mm_node != bo->pinned_node)) {
		mutex_lock(&bo->dev->struct_mutex);
		drm_mm_put_block(old_mem->mm_node);
		old_mem->mm_node = NULL;
		mutex_unlock(&bo->dev->struct_mutex);
	}
	old_mem->mm_node = NULL;
}

int drm_bo_move_ttm(struct drm_buffer_object *bo,
		    int evict, int no_wait, struct drm_bo_mem_reg *new_mem)
{
	struct drm_ttm *ttm = bo->ttm;
	struct drm_bo_mem_reg *old_mem = &bo->mem;
	uint64_t save_flags = old_mem->flags;
	uint64_t save_proposed_flags = old_mem->proposed_flags;
	int ret;

	if (old_mem->mem_type == DRM_BO_MEM_TT) {
		if (evict)
			drm_ttm_evict(ttm);
		else
			drm_ttm_unbind(ttm);

		drm_bo_free_old_node(bo);
		DRM_FLAG_MASKED(old_mem->flags,
				DRM_BO_FLAG_CACHED | DRM_BO_FLAG_MAPPABLE |
				DRM_BO_FLAG_MEM_LOCAL, DRM_BO_MASK_MEMTYPE);
		old_mem->mem_type = DRM_BO_MEM_LOCAL;
		save_flags = old_mem->flags;
	}
	if (new_mem->mem_type != DRM_BO_MEM_LOCAL) {
		ret = drm_ttm_bind(ttm, new_mem);
		if (ret)
			return ret;
	}

	*old_mem = *new_mem;
	new_mem->mm_node = NULL;
	old_mem->proposed_flags = save_proposed_flags;
	DRM_FLAG_MASKED(save_flags, new_mem->flags, DRM_BO_MASK_MEMTYPE);
	return 0;
}
EXPORT_SYMBOL(drm_bo_move_ttm);

/**
 * \c Return a kernel virtual address to the buffer object PCI memory.
 *
 * \param bo The buffer object.
 * \return Failure indication.
 *
 * Returns -EINVAL if the buffer object is currently not mappable.
 * Returns -ENOMEM if the ioremap operation failed.
 * Otherwise returns zero.
 *
 * After a successfull call, bo->iomap contains the virtual address, or NULL
 * if the buffer object content is not accessible through PCI space.
 * Call bo->mutex locked.
 */

int drm_mem_reg_ioremap(struct drm_device *dev, struct drm_bo_mem_reg *mem,
			void **virtual)
{
	struct drm_buffer_manager *bm = &dev->bm;
	struct drm_mem_type_manager *man = &bm->man[mem->mem_type];
	unsigned long bus_offset;
	unsigned long bus_size;
	unsigned long bus_base;
	int ret;
	void *addr;

	*virtual = NULL;
	ret = drm_bo_pci_offset(dev, mem, &bus_base, &bus_offset, &bus_size);
	if (ret || bus_size == 0)
		return ret;

	if (!(man->flags & _DRM_FLAG_NEEDS_IOREMAP))
		addr = (void *)(((u8 *) man->io_addr) + bus_offset);
	else {
		addr = ioremap_nocache(bus_base + bus_offset, bus_size);
		if (!addr)
			return -ENOMEM;
	}
	*virtual = addr;
	return 0;
}
EXPORT_SYMBOL(drm_mem_reg_ioremap);

/**
 * \c Unmap mapping obtained using drm_bo_ioremap
 *
 * \param bo The buffer object.
 *
 * Call bo->mutex locked.
 */

void drm_mem_reg_iounmap(struct drm_device *dev, struct drm_bo_mem_reg *mem,
			 void *virtual)
{
	struct drm_buffer_manager *bm;
	struct drm_mem_type_manager *man;

	bm = &dev->bm;
	man = &bm->man[mem->mem_type];

	if (virtual && (man->flags & _DRM_FLAG_NEEDS_IOREMAP))
		iounmap(virtual);
}

static int drm_copy_io_page(void *dst, void *src, unsigned long page)
{
	uint32_t *dstP =
	    (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
	uint32_t *srcP =
	    (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));

	int i;
	for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
		iowrite32(ioread32(srcP++), dstP++);
	return 0;
}

static int drm_copy_io_ttm_page(struct drm_ttm *ttm, void *src,
				unsigned long page)
{
	struct page *d = drm_ttm_get_page(ttm, page);
	void *dst;

	if (!d)
		return -ENOMEM;

	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
	dst = kmap(d);
	if (!dst)
		return -ENOMEM;

	memcpy_fromio(dst, src, PAGE_SIZE);
	kunmap(d);
	return 0;
}

static int drm_copy_ttm_io_page(struct drm_ttm *ttm, void *dst, unsigned long page)
{
	struct page *s = drm_ttm_get_page(ttm, page);
	void *src;

	if (!s)
		return -ENOMEM;

	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
	src = kmap(s);
	if (!src)
		return -ENOMEM;

	memcpy_toio(dst, src, PAGE_SIZE);
	kunmap(s);
	return 0;
}

int drm_bo_move_memcpy(struct drm_buffer_object *bo,
		       int evict, int no_wait, struct drm_bo_mem_reg *new_mem)
{
	struct drm_device *dev = bo->dev;
	struct drm_mem_type_manager *man = &dev->bm.man[new_mem->mem_type];
	struct drm_ttm *ttm = bo->ttm;
	struct drm_bo_mem_reg *old_mem = &bo->mem;
	struct drm_bo_mem_reg old_copy = *old_mem;
	void *old_iomap;
	void *new_iomap;
	int ret;
	uint64_t save_flags = old_mem->flags;
	uint64_t save_proposed_flags = old_mem->proposed_flags;
	unsigned long i;
	unsigned long page;
	unsigned long add = 0;
	int dir;

	ret = drm_mem_reg_ioremap(dev, old_mem, &old_iomap);
	if (ret)
		return ret;
	ret = drm_mem_reg_ioremap(dev, new_mem, &new_iomap);
	if (ret)
		goto out;

	if (old_iomap == NULL && new_iomap == NULL)
		goto out2;
	if (old_iomap == NULL && ttm == NULL)
		goto out2;

	add = 0;
	dir = 1;

	if ((old_mem->mem_type == new_mem->mem_type) &&
	    (new_mem->mm_node->start <
	     old_mem->mm_node->start + old_mem->mm_node->size)) {
		dir = -1;
		add = new_mem->num_pages - 1;
	}

	for (i = 0; i < new_mem->num_pages; ++i) {
		page = i * dir + add;
		if (old_iomap == NULL)
			ret = drm_copy_ttm_io_page(ttm, new_iomap, page);
		else if (new_iomap == NULL)
			ret = drm_copy_io_ttm_page(ttm, old_iomap, page);
		else
			ret = drm_copy_io_page(new_iomap, old_iomap, page);
		if (ret)
			goto out1;
	}
	mb();
out2:
	drm_bo_free_old_node(bo);

	*old_mem = *new_mem;
	new_mem->mm_node = NULL;
	old_mem->proposed_flags = save_proposed_flags;
	DRM_FLAG_MASKED(save_flags, new_mem->flags, DRM_BO_MASK_MEMTYPE);

	if ((man->flags & _DRM_FLAG_MEMTYPE_FIXED) && (ttm != NULL)) {
		drm_ttm_unbind(ttm);
		drm_ttm_destroy(ttm);
		bo->ttm = NULL;
	}

out1:
	drm_mem_reg_iounmap(dev, new_mem, new_iomap);
out:
	drm_mem_reg_iounmap(dev, &old_copy, old_iomap);
	return ret;
}
EXPORT_SYMBOL(drm_bo_move_memcpy);

/*
 * Transfer a buffer object's memory and LRU status to a newly
 * created object. User-space references remains with the old
 * object. Call bo->mutex locked.
 */

int drm_buffer_object_transfer(struct drm_buffer_object *bo,
			       struct drm_buffer_object **new_obj)
{
	struct drm_buffer_object *fbo;
	struct drm_device *dev = bo->dev;
	struct drm_buffer_manager *bm = &dev->bm;

	fbo = drm_ctl_calloc(1, sizeof(*fbo), DRM_MEM_BUFOBJ);
	if (!fbo)
		return -ENOMEM;

	*fbo = *bo;
	mutex_init(&fbo->mutex);
	mutex_lock(&fbo->mutex);
	mutex_lock(&dev->struct_mutex);

	DRM_INIT_WAITQUEUE(&bo->event_queue);
	INIT_LIST_HEAD(&fbo->ddestroy);
	INIT_LIST_HEAD(&fbo->lru);
	INIT_LIST_HEAD(&fbo->pinned_lru);
#ifdef DRM_ODD_MM_COMPAT
	INIT_LIST_HEAD(&fbo->vma_list);
	INIT_LIST_HEAD(&fbo->p_mm_list);
#endif

	fbo->fence = drm_fence_reference_locked(bo->fence);
	fbo->pinned_node = NULL;
	fbo->mem.mm_node->private = (void *)fbo;
	atomic_set(&fbo->usage, 1);
	atomic_inc(&bm->count);
	mutex_unlock(&dev->struct_mutex);
	mutex_unlock(&fbo->mutex);

	*new_obj = fbo;
	return 0;
}

/*
 * Since move is underway, we need to block signals in this function.
 * We cannot restart until it has finished.
 */

int drm_bo_move_accel_cleanup(struct drm_buffer_object *bo,
			      int evict, int no_wait, uint32_t fence_class,
			      uint32_t fence_type, uint32_t fence_flags,
			      struct drm_bo_mem_reg *new_mem)
{
	struct drm_device *dev = bo->dev;
	struct drm_mem_type_manager *man = &dev->bm.man[new_mem->mem_type];
	struct drm_bo_mem_reg *old_mem = &bo->mem;
	int ret;
	uint64_t save_flags = old_mem->flags;
	uint64_t save_proposed_flags = old_mem->proposed_flags;
	struct drm_buffer_object *old_obj;

	if (bo->fence)
		drm_fence_usage_deref_unlocked(&bo->fence);
	ret = drm_fence_object_create(dev, fence_class, fence_type,
				      fence_flags | DRM_FENCE_FLAG_EMIT,
				      &bo->fence);
	bo->fence_type = fence_type;
	if (ret)
		return ret;

#ifdef DRM_ODD_MM_COMPAT
	/*
	 * In this mode, we don't allow pipelining a copy blit,
	 * since the buffer will be accessible from user space
	 * the moment we return and rebuild the page tables.
	 *
	 * With normal vm operation, page tables are rebuilt
	 * on demand using fault(), which waits for buffer idle.
	 */
	if (1)
#else
	if (evict || ((bo->mem.mm_node == bo->pinned_node) &&
		      bo->mem.mm_node != NULL))
#endif
	{
		ret = drm_bo_wait(bo, 0, 1, 0);
		if (ret)
			return ret;

		drm_bo_free_old_node(bo);

		if ((man->flags & _DRM_FLAG_MEMTYPE_FIXED) && (bo->ttm != NULL)) {
			drm_ttm_unbind(bo->ttm);
			drm_ttm_destroy(bo->ttm);
			bo->ttm = NULL;
		}
	} else {

		/* This should help pipeline ordinary buffer moves.
		 *
		 * Hang old buffer memory on a new buffer object,
		 * and leave it to be released when the GPU
		 * operation has completed.
		 */

		ret = drm_buffer_object_transfer(bo, &old_obj);

		if (ret)
			return ret;

		if (!(man->flags & _DRM_FLAG_MEMTYPE_FIXED))
			old_obj->ttm = NULL;
		else
			bo->ttm = NULL;

		mutex_lock(&dev->struct_mutex);
		list_del_init(&old_obj->lru);
		DRM_FLAG_MASKED(bo->priv_flags, 0, _DRM_BO_FLAG_UNFENCED);
		drm_bo_add_to_lru(old_obj);

		drm_bo_usage_deref_locked(&old_obj);
		mutex_unlock(&dev->struct_mutex);

	}

	*old_mem = *new_mem;
	new_mem->mm_node = NULL;
	old_mem->proposed_flags = save_proposed_flags;
	DRM_FLAG_MASKED(save_flags, new_mem->flags, DRM_BO_MASK_MEMTYPE);
	return 0;
}
EXPORT_SYMBOL(drm_bo_move_accel_cleanup);

int drm_bo_same_page(unsigned long offset,
		     unsigned long offset2)
{
	return (offset & PAGE_MASK) == (offset2 & PAGE_MASK);
}
EXPORT_SYMBOL(drm_bo_same_page);

unsigned long drm_bo_offset_end(unsigned long offset,
				unsigned long end)
{
	offset = (offset + PAGE_SIZE) & PAGE_MASK;
	return (end < offset) ? end : offset;
}
EXPORT_SYMBOL(drm_bo_offset_end);

static pgprot_t drm_kernel_io_prot(uint32_t map_type)
{
	pgprot_t tmp = PAGE_KERNEL;

#if defined(__i386__) || defined(__x86_64__)
#ifdef USE_PAT_WC
#warning using pat
	if (drm_use_pat() && map_type == _DRM_TTM) {
		pgprot_val(tmp) |= _PAGE_PAT;
		return tmp;
	}
#endif
	if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
		pgprot_val(tmp) |= _PAGE_PCD;
		pgprot_val(tmp) &= ~_PAGE_PWT;
	}
#elif defined(__powerpc__)
	pgprot_val(tmp) |= _PAGE_NO_CACHE;
	if (map_type == _DRM_REGISTERS)
		pgprot_val(tmp) |= _PAGE_GUARDED;
#endif
#if defined(__ia64__)
	if (map_type == _DRM_TTM)
		tmp = pgprot_writecombine(tmp);
	else
		tmp = pgprot_noncached(tmp);
#endif
	return tmp;
}

static int drm_bo_ioremap(struct drm_buffer_object *bo, unsigned long bus_base,
			  unsigned long bus_offset, unsigned long bus_size,
			  struct drm_bo_kmap_obj *map)
{
	struct drm_device *dev = bo->dev;
	struct drm_bo_mem_reg *mem = &bo->mem;
	struct drm_mem_type_manager *man = &dev->bm.man[mem->mem_type];

	if (!(man->flags & _DRM_FLAG_NEEDS_IOREMAP)) {
		map->bo_kmap_type = bo_map_premapped;
		map->virtual = (void *)(((u8 *) man->io_addr) + bus_offset);
	} else {
		map->bo_kmap_type = bo_map_iomap;
		map->virtual = ioremap_nocache(bus_base + bus_offset, bus_size);
	}
	return (!map->virtual) ? -ENOMEM : 0;
}

static int drm_bo_kmap_ttm(struct drm_buffer_object *bo,
			   unsigned long start_page, unsigned long num_pages,
			   struct drm_bo_kmap_obj *map)
{
	struct drm_device *dev = bo->dev;
	struct drm_bo_mem_reg *mem = &bo->mem;
	struct drm_mem_type_manager *man = &dev->bm.man[mem->mem_type];
	pgprot_t prot;
	struct drm_ttm *ttm = bo->ttm;
	struct page *d;
	int i;

	BUG_ON(!ttm);

	if (num_pages == 1 && (mem->flags & DRM_BO_FLAG_CACHED)) {

		/*
		 * We're mapping a single page, and the desired
		 * page protection is consistent with the bo.
		 */

		map->bo_kmap_type = bo_map_kmap;
		map->page = drm_ttm_get_page(ttm, start_page);
		map->virtual = kmap(map->page);
	} else {
		/*
		 * Populate the part we're mapping;
		 */

		for (i = start_page; i < start_page + num_pages; ++i) {
			d = drm_ttm_get_page(ttm, i);
			if (!d)
				return -ENOMEM;
		}

		/*
		 * We need to use vmap to get the desired page protection
		 * or to make the buffer object look contigous.
		 */

		prot = (mem->flags & DRM_BO_FLAG_CACHED) ?
			PAGE_KERNEL :
			drm_kernel_io_prot(man->drm_bus_maptype);
		map->bo_kmap_type = bo_map_vmap;
		map->virtual = vmap(ttm->pages + start_page,
				    num_pages, 0, prot);
	}
	return (!map->virtual) ? -ENOMEM : 0;
}

/*
 * This function is to be used for kernel mapping of buffer objects.
 * It chooses the appropriate mapping method depending on the memory type
 * and caching policy the buffer currently has.
 * Mapping multiple pages or buffers that live in io memory is a bit slow and
 * consumes vmalloc space. Be restrictive with such mappings.
 * Mapping single pages usually returns the logical kernel address,
 * (which is fast)
 * BUG may use slower temporary mappings for high memory pages or
 * uncached / write-combined pages.
 *
 * The function fills in a drm_bo_kmap_obj which can be used to return the
 * kernel virtual address of the buffer.
 *
 * Code servicing a non-priviliged user request is only allowed to map one
 * page at a time. We might need to implement a better scheme to stop such
 * processes from consuming all vmalloc space.
 */

int drm_bo_kmap(struct drm_buffer_object *bo, unsigned long start_page,
		unsigned long num_pages, struct drm_bo_kmap_obj *map)
{
	int ret;
	unsigned long bus_base;
	unsigned long bus_offset;
	unsigned long bus_size;

	map->virtual = NULL;

	if (num_pages > bo->num_pages)
		return -EINVAL;
	if (start_page > bo->num_pages)
		return -EINVAL;
#if 0
	if (num_pages > 1 && !DRM_SUSER(DRM_CURPROC))
		return -EPERM;
#endif
	ret = drm_bo_pci_offset(bo->dev, &bo->mem, &bus_base,
				&bus_offset, &bus_size);

	if (ret)
		return ret;

	if (bus_size == 0) {
		return drm_bo_kmap_ttm(bo, start_page, num_pages, map);
	} else {
		bus_offset += start_page << PAGE_SHIFT;
		bus_size = num_pages << PAGE_SHIFT;
		return drm_bo_ioremap(bo, bus_base, bus_offset, bus_size, map);
	}
}
EXPORT_SYMBOL(drm_bo_kmap);

void drm_bo_kunmap(struct drm_bo_kmap_obj *map)
{
	if (!map->virtual)
		return;

	switch (map->bo_kmap_type) {
	case bo_map_iomap:
		iounmap(map->virtual);
		break;
	case bo_map_vmap:
		vunmap(map->virtual);
		break;
	case bo_map_kmap:
		kunmap(map->page);
		break;
	case bo_map_premapped:
		break;
	default:
		BUG();
	}
	map->virtual = NULL;
	map->page = NULL;
}
EXPORT_SYMBOL(drm_bo_kunmap);