drivers/llvmpipe/lp_texture.c

/**************************************************************************
 *
 * Copyright 2006 VMware, Inc.
 * 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 VMWARE 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:
  *   Keith Whitwell <keithw@vmware.com>
  *   Michel Dänzer <daenzer@vmware.com>
  */

#include <stdio.h>

#include "pipe/p_context.h"
#include "pipe/p_defines.h"

#include "util/simple_mtx.h"
#include "util/u_inlines.h"
#include "util/u_cpu_detect.h"
#include "util/format/u_format.h"
#include "util/u_math.h"
#include "util/u_memory.h"
#include "util/u_transfer.h"

#include "lp_context.h"
#include "lp_flush.h"
#include "lp_screen.h"
#include "lp_texture.h"
#include "lp_setup.h"
#include "lp_state.h"
#include "lp_rast.h"

#include "frontend/sw_winsys.h"
#include "git_sha1.h"

#ifndef _WIN32
#include "drm-uapi/drm_fourcc.h"
#endif


#ifdef DEBUG
static struct llvmpipe_resource resource_list;
static simple_mtx_t resource_list_mutex = SIMPLE_MTX_INITIALIZER;
#endif
static unsigned id_counter = 0;


/**
 * Conventional allocation path for non-display textures:
 * Compute strides and allocate data (unless asked not to).
 */
static bool
llvmpipe_texture_layout(struct llvmpipe_screen *screen,
                        struct llvmpipe_resource *lpr,
                        bool allocate)
{
   struct pipe_resource *pt = &lpr->base;
   unsigned width = pt->width0;
   unsigned height = pt->height0;
   unsigned depth = pt->depth0;
   uint64_t total_size = 0;
   unsigned layers = pt->array_size;
   unsigned num_samples = util_res_sample_count(pt);

   /* XXX: This alignment here (same for displaytarget) was added for the
    * purpose of ARB_map_buffer_alignment. I am not convinced it's needed for
    * non-buffer resources. Otherwise we'd want the max of cacheline size and
    * 16 (max size of a block for all formats) though this should not be
    * strictly necessary neither. In any case it can only affect compressed or
    * 1d textures.
    */
   uint64_t mip_align = MAX2(64, util_get_cpu_caps()->cacheline);

   /* KVM on Linux requires memory mapping to be aligned to the page size,
    * otherwise Linux kernel errors out on trying to map host GPU mapping
    * to guest (ARB_map_buffer_range). The improper alignment creates trouble
    * for the virgl driver when host uses llvmpipe, causing Qemu and crosvm to
    * bail out on the KVM error.
    */
   if (lpr->base.flags & PIPE_RESOURCE_FLAG_MAP_PERSISTENT)
      os_get_page_size(&mip_align);

   assert(LP_MAX_TEXTURE_2D_LEVELS <= LP_MAX_TEXTURE_LEVELS);
   assert(LP_MAX_TEXTURE_3D_LEVELS <= LP_MAX_TEXTURE_LEVELS);

   for (unsigned level = 0; level <= pt->last_level; level++) {
      uint64_t mipsize;
      unsigned align_x, align_y, nblocksx, nblocksy, block_size, num_slices;

      /* Row stride and image stride */

      /* For non-compressed formats we need 4x4 pixel alignment
       * so we can read/write LP_RASTER_BLOCK_SIZE when rendering to them.
       * We also want cache line size in x direction,
       * otherwise same cache line could end up in multiple threads.
       * For explicit 1d resources however we reduce this to 4x1 and
       * handle specially in render output code (as we need to do special
       * handling there for buffers in any case).
       */
      if (util_format_is_compressed(pt->format)) {
         align_x = align_y = 1;
      } else {
         align_x = LP_RASTER_BLOCK_SIZE;
         if (llvmpipe_resource_is_1d(&lpr->base))
            align_y = 1;
         else
            align_y = LP_RASTER_BLOCK_SIZE;
      }

      nblocksx = util_format_get_nblocksx(pt->format,
                                          align(width, align_x));
      nblocksy = util_format_get_nblocksy(pt->format,
                                          align(height, align_y));
      block_size = util_format_get_blocksize(pt->format);

      if (util_format_is_compressed(pt->format))
         lpr->row_stride[level] = nblocksx * block_size;
      else
         lpr->row_stride[level] = align(nblocksx * block_size,
                                        util_get_cpu_caps()->cacheline);

      lpr->img_stride[level] = (uint64_t)lpr->row_stride[level] * nblocksy;

      /* Number of 3D image slices, cube faces or texture array layers */
      if (lpr->base.target == PIPE_TEXTURE_CUBE) {
         assert(layers == 6);
      }

      if (lpr->base.target == PIPE_TEXTURE_3D)
         num_slices = depth;
      else if (lpr->base.target == PIPE_TEXTURE_1D_ARRAY ||
               lpr->base.target == PIPE_TEXTURE_2D_ARRAY ||
               lpr->base.target == PIPE_TEXTURE_CUBE ||
               lpr->base.target == PIPE_TEXTURE_CUBE_ARRAY)
         num_slices = layers;
      else
         num_slices = 1;

      mipsize = lpr->img_stride[level] * num_slices;
      lpr->mip_offsets[level] = total_size;

      total_size += align64(mipsize, mip_align);

      /* Compute size of next mipmap level */
      width = u_minify(width, 1);
      height = u_minify(height, 1);
      depth = u_minify(depth, 1);
   }

   lpr->sample_stride = total_size;
   total_size *= num_samples;

   lpr->size_required = total_size;
   if (allocate) {
      if (total_size > LP_MAX_TEXTURE_SIZE)
         goto fail;

      lpr->tex_data = align_malloc(total_size, mip_align);
      if (!lpr->tex_data) {
         return false;
      } else {
         memset(lpr->tex_data, 0, total_size);
      }
   }

   return true;

fail:
   return false;
}


/**
 * Check the size of the texture specified by 'res'.
 * \return TRUE if OK, FALSE if too large.
 */
static bool
llvmpipe_can_create_resource(struct pipe_screen *screen,
                             const struct pipe_resource *res)
{
   struct llvmpipe_resource lpr;
   memset(&lpr, 0, sizeof(lpr));
   lpr.base = *res;
   if (!llvmpipe_texture_layout(llvmpipe_screen(screen), &lpr, false))
      return false;

   return lpr.size_required <= LP_MAX_TEXTURE_SIZE;
}


static bool
llvmpipe_displaytarget_layout(struct llvmpipe_screen *screen,
                              struct llvmpipe_resource *lpr,
                              const void *map_front_private)
{
   struct sw_winsys *winsys = screen->winsys;

   /* Round up the surface size to a multiple of the tile size to
    * avoid tile clipping.
    */
   const unsigned width = MAX2(1, align(lpr->base.width0, TILE_SIZE));
   const unsigned height = MAX2(1, align(lpr->base.height0, TILE_SIZE));

   lpr->dt = winsys->displaytarget_create(winsys,
                                          lpr->base.bind,
                                          lpr->base.format,
                                          width, height,
                                          64,
                                          map_front_private,
                                          &lpr->row_stride[0] );

   return lpr->dt != NULL;
}


static struct pipe_resource *
llvmpipe_resource_create_all(struct pipe_screen *_screen,
                             const struct pipe_resource *templat,
                             const void *map_front_private,
                             bool alloc_backing)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(_screen);
   struct llvmpipe_resource *lpr = CALLOC_STRUCT(llvmpipe_resource);
   if (!lpr)
      return NULL;

   lpr->base = *templat;
   lpr->screen = screen;
   pipe_reference_init(&lpr->base.reference, 1);
   lpr->base.screen = &screen->base;

   /* assert(lpr->base.bind); */

   if (llvmpipe_resource_is_texture(&lpr->base)) {
      if (lpr->base.bind & (PIPE_BIND_DISPLAY_TARGET |
                            PIPE_BIND_SCANOUT |
                            PIPE_BIND_SHARED)) {
         /* displayable surface */
         if (!llvmpipe_displaytarget_layout(screen, lpr, map_front_private))
            goto fail;
      } else {
         /* texture map */
         if (!llvmpipe_texture_layout(screen, lpr, alloc_backing))
            goto fail;
      }
   } else {
      /* other data (vertex buffer, const buffer, etc) */
      const uint bytes = templat->width0;
      assert(util_format_get_blocksize(templat->format) == 1);
      assert(templat->height0 == 1);
      assert(templat->depth0 == 1);
      assert(templat->last_level == 0);
      /*
       * Reserve some extra storage since if we'd render to a buffer we
       * read/write always LP_RASTER_BLOCK_SIZE pixels, but the element
       * offset doesn't need to be aligned to LP_RASTER_BLOCK_SIZE.
       */
      /*
       * buffers don't really have stride but it's probably safer
       * (for code doing same calculations for buffers and textures)
       * to put something sane in there.
       */
      lpr->row_stride[0] = bytes;

      lpr->size_required = bytes;
      if (!(templat->flags & PIPE_RESOURCE_FLAG_DONT_OVER_ALLOCATE))
         lpr->size_required += (LP_RASTER_BLOCK_SIZE - 1) * 4 * sizeof(float);

      if (alloc_backing) {
         uint64_t alignment = sizeof(uint64_t) * 16;

         if (templat->flags & PIPE_RESOURCE_FLAG_MAP_PERSISTENT)
            os_get_page_size(&alignment);

         lpr->data = align_malloc(lpr->size_required, alignment);

         if (!lpr->data)
            goto fail;
         memset(lpr->data, 0, bytes);
      }
   }

   lpr->id = id_counter++;

#ifdef DEBUG
   simple_mtx_lock(&resource_list_mutex);
   list_addtail(&lpr->list, &resource_list.list);
   simple_mtx_unlock(&resource_list_mutex);
#endif

   return &lpr->base;

 fail:
   FREE(lpr);
   return NULL;
}


static struct pipe_resource *
llvmpipe_resource_create_front(struct pipe_screen *_screen,
                               const struct pipe_resource *templat,
                               const void *map_front_private)
{
   return llvmpipe_resource_create_all(_screen, templat,
                                       map_front_private, true);
}


static struct pipe_resource *
llvmpipe_resource_create(struct pipe_screen *_screen,
                         const struct pipe_resource *templat)
{
   return llvmpipe_resource_create_front(_screen, templat, NULL);
}


static struct pipe_resource *
llvmpipe_resource_create_unbacked(struct pipe_screen *_screen,
                                  const struct pipe_resource *templat,
                                  uint64_t *size_required)
{
   struct pipe_resource *pt =
      llvmpipe_resource_create_all(_screen, templat, NULL, false);
   if (!pt)
      return pt;
   struct llvmpipe_resource *lpr = llvmpipe_resource(pt);
   lpr->backable = true;
   *size_required = lpr->size_required;
   return pt;
}


static struct pipe_memory_object *
llvmpipe_memobj_create_from_handle(struct pipe_screen *pscreen,
                                   struct winsys_handle *handle,
                                   bool dedicated)
{
#ifdef PIPE_MEMORY_FD
   struct llvmpipe_memory_object *memobj = CALLOC_STRUCT(llvmpipe_memory_object);

   if (handle->type == WINSYS_HANDLE_TYPE_FD &&
       pscreen->import_memory_fd(pscreen, handle->handle, &memobj->data, &memobj->size)) {
      return &memobj->b;
   }
   free(memobj);
#endif
   return NULL;
}


static void
llvmpipe_memobj_destroy(struct pipe_screen *pscreen,
                        struct pipe_memory_object *memobj)
{
   if (!memobj)
      return;
   struct llvmpipe_memory_object *lpmo = llvmpipe_memory_object(memobj);
#ifdef PIPE_MEMORY_FD
   pscreen->free_memory_fd(pscreen, lpmo->data);
#endif
   free(lpmo);
}


static struct pipe_resource *
llvmpipe_resource_from_memobj(struct pipe_screen *pscreen,
                              const struct pipe_resource *templat,
                              struct pipe_memory_object *memobj,
                              uint64_t offset)
{
   if (!memobj)
      return NULL;
   struct llvmpipe_screen *screen = llvmpipe_screen(pscreen);
   struct llvmpipe_memory_object *lpmo = llvmpipe_memory_object(memobj);
   struct llvmpipe_resource *lpr = CALLOC_STRUCT(llvmpipe_resource);
   lpr->base = *templat;

   lpr->screen = screen;
   pipe_reference_init(&lpr->base.reference, 1);
   lpr->base.screen = &screen->base;

   if (llvmpipe_resource_is_texture(&lpr->base)) {
      /* texture map */
      if (!llvmpipe_texture_layout(screen, lpr, false))
         goto fail;
      if (lpmo->size < lpr->size_required)
         goto fail;
      lpr->tex_data = lpmo->data;
   } else {
      /* other data (vertex buffer, const buffer, etc) */
      const uint bytes = templat->width0;
      assert(util_format_get_blocksize(templat->format) == 1);
      assert(templat->height0 == 1);
      assert(templat->depth0 == 1);
      assert(templat->last_level == 0);
      /*
       * Reserve some extra storage since if we'd render to a buffer we
       * read/write always LP_RASTER_BLOCK_SIZE pixels, but the element
       * offset doesn't need to be aligned to LP_RASTER_BLOCK_SIZE.
       */
      /*
       * buffers don't really have stride but it's probably safer
       * (for code doing same calculations for buffers and textures)
       * to put something reasonable in there.
       */
      lpr->row_stride[0] = bytes;

      lpr->size_required = bytes;
      if (!(templat->flags & PIPE_RESOURCE_FLAG_DONT_OVER_ALLOCATE))
         lpr->size_required += (LP_RASTER_BLOCK_SIZE - 1) * 4 * sizeof(float);

      if (lpmo->size < lpr->size_required)
         goto fail;
      lpr->data = lpmo->data;
   }
   lpr->id = id_counter++;
   lpr->imported_memory = true;

#ifdef DEBUG
   simple_mtx_lock(&resource_list_mutex);
   list_addtail(&lpr->list, &resource_list.list);
   simple_mtx_unlock(&resource_list_mutex);
#endif

   return &lpr->base;

fail:
   free(lpr);
   return NULL;
}

static void
llvmpipe_resource_destroy(struct pipe_screen *pscreen,
                          struct pipe_resource *pt)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(pscreen);
   struct llvmpipe_resource *lpr = llvmpipe_resource(pt);

   if (!lpr->backable && !lpr->user_ptr) {
      if (lpr->dt) {
         /* display target */
         struct sw_winsys *winsys = screen->winsys;
         winsys->displaytarget_destroy(winsys, lpr->dt);
      } else if (llvmpipe_resource_is_texture(pt)) {
         /* free linear image data */
         if (lpr->tex_data) {
            if (!lpr->imported_memory)
               align_free(lpr->tex_data);
            lpr->tex_data = NULL;
         }
      } else if (lpr->data) {
         if (!lpr->imported_memory)
            align_free(lpr->data);
      }
   }
#ifdef DEBUG
   simple_mtx_lock(&resource_list_mutex);
   if (!list_is_empty(&lpr->list))
      list_del(&lpr->list);
   simple_mtx_unlock(&resource_list_mutex);
#endif

   FREE(lpr);
}


/**
 * Map a resource for read/write.
 */
void *
llvmpipe_resource_map(struct pipe_resource *resource,
                      unsigned level,
                      unsigned layer,
                      enum lp_texture_usage tex_usage)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);
   uint8_t *map;

   assert(level < LP_MAX_TEXTURE_LEVELS);
   assert(layer < (u_minify(resource->depth0, level) + resource->array_size - 1));

   assert(tex_usage == LP_TEX_USAGE_READ ||
          tex_usage == LP_TEX_USAGE_READ_WRITE ||
          tex_usage == LP_TEX_USAGE_WRITE_ALL);

   if (lpr->dt) {
      /* display target */
      struct llvmpipe_screen *screen = lpr->screen;
      struct sw_winsys *winsys = screen->winsys;
      unsigned dt_usage;

      if (tex_usage == LP_TEX_USAGE_READ) {
         dt_usage = PIPE_MAP_READ;
      } else {
         dt_usage = PIPE_MAP_READ_WRITE;
      }

      assert(level == 0);
      assert(layer == 0);

      /* FIXME: keep map count? */
      map = winsys->displaytarget_map(winsys, lpr->dt, dt_usage);

      /* install this linear image in texture data structure */
      lpr->tex_data = map;

      return map;
   } else if (llvmpipe_resource_is_texture(resource)) {

      map = llvmpipe_get_texture_image_address(lpr, layer, level);
      return map;
   } else {
      return lpr->data;
   }
}


/**
 * Unmap a resource.
 */
void
llvmpipe_resource_unmap(struct pipe_resource *resource,
                        unsigned level,
                        unsigned layer)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);

   if (lpr->dt) {
      /* display target */
      struct llvmpipe_screen *lp_screen = lpr->screen;
      struct sw_winsys *winsys = lp_screen->winsys;

      assert(level == 0);
      assert(layer == 0);

      winsys->displaytarget_unmap(winsys, lpr->dt);
   }
}


void *
llvmpipe_resource_data(struct pipe_resource *resource)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);

   assert(!llvmpipe_resource_is_texture(resource));

   return lpr->data;
}


static struct pipe_resource *
llvmpipe_resource_from_handle(struct pipe_screen *_screen,
                              const struct pipe_resource *template,
                              struct winsys_handle *whandle,
                              unsigned usage)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(_screen);
   struct sw_winsys *winsys = screen->winsys;
   struct llvmpipe_resource *lpr;

   /* XXX Seems like from_handled depth textures doesn't work that well */

   lpr = CALLOC_STRUCT(llvmpipe_resource);
   if (!lpr) {
      goto no_lpr;
   }

   lpr->base = *template;
   lpr->screen = screen;
   pipe_reference_init(&lpr->base.reference, 1);
   lpr->base.screen = _screen;

   /*
    * Looks like unaligned displaytargets work just fine,
    * at least sampler/render ones.
    */
#if 0
   assert(lpr->base.width0 == width);
   assert(lpr->base.height0 == height);
#endif

   lpr->dt = winsys->displaytarget_from_handle(winsys,
                                               template,
                                               whandle,
                                               &lpr->row_stride[0]);
   if (!lpr->dt) {
      goto no_dt;
   }

   lpr->id = id_counter++;

#ifdef DEBUG
   simple_mtx_lock(&resource_list_mutex);
   list_addtail(&lpr->list, &resource_list.list);
   simple_mtx_unlock(&resource_list_mutex);
#endif

   return &lpr->base;

no_dt:
   FREE(lpr);
no_lpr:
   return NULL;
}


static bool
llvmpipe_resource_get_handle(struct pipe_screen *screen,
                             struct pipe_context *ctx,
                             struct pipe_resource *pt,
                             struct winsys_handle *whandle,
                             unsigned usage)
{
   struct sw_winsys *winsys = llvmpipe_screen(screen)->winsys;
   struct llvmpipe_resource *lpr = llvmpipe_resource(pt);

   assert(lpr->dt);
   if (!lpr->dt)
      return false;

   return winsys->displaytarget_get_handle(winsys, lpr->dt, whandle);
}


static struct pipe_resource *
llvmpipe_resource_from_user_memory(struct pipe_screen *_screen,
                                   const struct pipe_resource *resource,
                                   void *user_memory)
{
   struct llvmpipe_screen *screen = llvmpipe_screen(_screen);
   struct llvmpipe_resource *lpr;

   lpr = CALLOC_STRUCT(llvmpipe_resource);
   if (!lpr) {
      return NULL;
   }

   lpr->base = *resource;
   lpr->screen = screen;
   pipe_reference_init(&lpr->base.reference, 1);
   lpr->base.screen = _screen;

   if (llvmpipe_resource_is_texture(&lpr->base)) {
      if (!llvmpipe_texture_layout(screen, lpr, false))
         goto fail;

      lpr->tex_data = user_memory;
   } else
      lpr->data = user_memory;
   lpr->user_ptr = true;
#ifdef DEBUG
   simple_mtx_lock(&resource_list_mutex);
   list_addtail(&lpr->list, &resource_list.list);
   simple_mtx_unlock(&resource_list_mutex);
#endif
   return &lpr->base;
fail:
   FREE(lpr);
   return NULL;
}


void *
llvmpipe_transfer_map_ms(struct pipe_context *pipe,
                         struct pipe_resource *resource,
                         unsigned level,
                         unsigned usage,
                         unsigned sample,
                         const struct pipe_box *box,
                         struct pipe_transfer **transfer)
{
   struct llvmpipe_context *llvmpipe = llvmpipe_context(pipe);
   struct llvmpipe_screen *screen = llvmpipe_screen(pipe->screen);
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);
   struct llvmpipe_transfer *lpt;
   struct pipe_transfer *pt;
   uint8_t *map;
   enum pipe_format format;

   assert(resource);
   assert(level <= resource->last_level);

   /*
    * Transfers, like other pipe operations, must happen in order, so flush
    * the context if necessary.
    */
   if (!(usage & PIPE_MAP_UNSYNCHRONIZED)) {
      bool read_only = !(usage & PIPE_MAP_WRITE);
      bool do_not_block = !!(usage & PIPE_MAP_DONTBLOCK);
      if (!llvmpipe_flush_resource(pipe, resource,
                                   level,
                                   read_only,
                                   true, /* cpu_access */
                                   do_not_block,
                                   __func__)) {
         /*
          * It would have blocked, but gallium frontend requested no to.
          */
         assert(do_not_block);
         return NULL;
      }
   }

   /* Check if we're mapping a current constant buffer */
   if ((usage & PIPE_MAP_WRITE) &&
       (resource->bind & PIPE_BIND_CONSTANT_BUFFER)) {
      unsigned i;
      for (i = 0; i < ARRAY_SIZE(llvmpipe->constants[PIPE_SHADER_FRAGMENT]); ++i) {
         if (resource == llvmpipe->constants[PIPE_SHADER_FRAGMENT][i].buffer) {
            /* constants may have changed */
            llvmpipe->dirty |= LP_NEW_FS_CONSTANTS;
            break;
         }
      }
   }

   lpt = CALLOC_STRUCT(llvmpipe_transfer);
   if (!lpt)
      return NULL;
   pt = &lpt->base;
   pipe_resource_reference(&pt->resource, resource);
   pt->box = *box;
   pt->level = level;
   pt->stride = lpr->row_stride[level];
   pt->layer_stride = lpr->img_stride[level];
   pt->usage = usage;
   *transfer = pt;

   assert(level < LP_MAX_TEXTURE_LEVELS);

   /*
   printf("tex_transfer_map(%d, %d  %d x %d of %d x %d,  usage %d)\n",
          transfer->x, transfer->y, transfer->width, transfer->height,
          transfer->texture->width0,
          transfer->texture->height0,
          transfer->usage);
   */

   enum lp_texture_usage tex_usage;
   const char *mode;
   if (usage == PIPE_MAP_READ) {
      tex_usage = LP_TEX_USAGE_READ;
      mode = "read";
   } else {
      tex_usage = LP_TEX_USAGE_READ_WRITE;
      mode = "read/write";
   }

   if (0) {
      printf("transfer map tex %u  mode %s\n", lpr->id, mode);
   }

   format = lpr->base.format;

   map = llvmpipe_resource_map(resource, level, box->z, tex_usage);


   /* May want to do different things here depending on read/write nature
    * of the map:
    */
   if (usage & PIPE_MAP_WRITE) {
      /* Do something to notify sharing contexts of a texture change.
       */
      screen->timestamp++;
   }

   map +=
      box->y / util_format_get_blockheight(format) * pt->stride +
      box->x / util_format_get_blockwidth(format) * util_format_get_blocksize(format);

   map += sample * lpr->sample_stride;
   return map;
}


static void *
llvmpipe_transfer_map(struct pipe_context *pipe,
                      struct pipe_resource *resource,
                      unsigned level,
                      unsigned usage,
                      const struct pipe_box *box,
                      struct pipe_transfer **transfer)
{
   return llvmpipe_transfer_map_ms(pipe, resource, level, usage, 0,
                                   box, transfer);
}


static void
llvmpipe_transfer_unmap(struct pipe_context *pipe,
                        struct pipe_transfer *transfer)
{
   assert(transfer->resource);

   llvmpipe_resource_unmap(transfer->resource,
                           transfer->level,
                           transfer->box.z);

   /* Effectively do the texture_update work here - if texture images
    * needed post-processing to put them into hardware layout, this is
    * where it would happen.  For llvmpipe, nothing to do.
    */
   assert (transfer->resource);
   pipe_resource_reference(&transfer->resource, NULL);
   FREE(transfer);
}


unsigned int
llvmpipe_is_resource_referenced(struct pipe_context *pipe,
                                struct pipe_resource *presource,
                                unsigned level)
{
   struct llvmpipe_context *llvmpipe = llvmpipe_context(pipe);
   if (!(presource->bind & (PIPE_BIND_DEPTH_STENCIL |
                            PIPE_BIND_RENDER_TARGET |
                            PIPE_BIND_SAMPLER_VIEW |
                            PIPE_BIND_CONSTANT_BUFFER |
                            PIPE_BIND_SHADER_BUFFER |
                            PIPE_BIND_SHADER_IMAGE)))
      return LP_UNREFERENCED;

   return lp_setup_is_resource_referenced(llvmpipe->setup, presource);
}


/**
 * Returns the largest possible alignment for a format in llvmpipe
 */
unsigned
llvmpipe_get_format_alignment(enum pipe_format format)
{
   const struct util_format_description *desc = util_format_description(format);
   unsigned size = 0;

   for (unsigned i = 0; i < desc->nr_channels; ++i) {
      size += desc->channel[i].size;
   }

   unsigned bytes = size / 8;

   if (!util_is_power_of_two_or_zero(bytes)) {
      bytes /= desc->nr_channels;
   }

   if (bytes % 2 || bytes < 1) {
      return 1;
   } else {
      return bytes;
   }
}


/**
 * Create buffer which wraps user-space data.
 * XXX unreachable.
 */
struct pipe_resource *
llvmpipe_user_buffer_create(struct pipe_screen *screen,
                            void *ptr,
                            unsigned bytes,
                            unsigned bind_flags)
{
   struct llvmpipe_resource *buffer;

   buffer = CALLOC_STRUCT(llvmpipe_resource);
   if (!buffer)
      return NULL;

   buffer->screen = llvmpipe_screen(screen);
   pipe_reference_init(&buffer->base.reference, 1);
   buffer->base.screen = screen;
   buffer->base.format = PIPE_FORMAT_R8_UNORM; /* ?? */
   buffer->base.bind = bind_flags;
   buffer->base.usage = PIPE_USAGE_IMMUTABLE;
   buffer->base.flags = 0;
   buffer->base.width0 = bytes;
   buffer->base.height0 = 1;
   buffer->base.depth0 = 1;
   buffer->base.array_size = 1;
   buffer->user_ptr = true;
   buffer->data = ptr;

   return &buffer->base;
}


/**
 * Compute size (in bytes) need to store a texture image / mipmap level,
 * for just one cube face, one array layer or one 3D texture slice
 */
static unsigned
tex_image_face_size(const struct llvmpipe_resource *lpr, unsigned level)
{
   return lpr->img_stride[level];
}


/**
 * Return pointer to a 2D texture image/face/slice.
 * No tiled/linear conversion is done.
 */
uint8_t *
llvmpipe_get_texture_image_address(struct llvmpipe_resource *lpr,
                                   unsigned face_slice, unsigned level)
{
   assert(llvmpipe_resource_is_texture(&lpr->base));

   unsigned offset = lpr->mip_offsets[level];

   if (face_slice > 0)
      offset += face_slice * tex_image_face_size(lpr, level);

   return (uint8_t *) lpr->tex_data + offset;
}


/**
 * Return size of resource in bytes
 */
unsigned
llvmpipe_resource_size(const struct pipe_resource *resource)
{
   const struct llvmpipe_resource *lpr = llvmpipe_resource_const(resource);
   unsigned size = 0;

   if (llvmpipe_resource_is_texture(resource)) {
      /* Note this will always return 0 for displaytarget resources */
      size = lpr->total_alloc_size;
   } else {
      size = resource->width0;
   }
   return size;
}


static void
llvmpipe_memory_barrier(struct pipe_context *pipe,
                        unsigned flags)
{
   /* this may be an overly large hammer for this nut. */
   llvmpipe_finish(pipe, "barrier");
}


static struct pipe_memory_allocation *
llvmpipe_allocate_memory(struct pipe_screen *screen, uint64_t size)
{
   uint64_t alignment;
   if (!os_get_page_size(&alignment))
      alignment = 256;
   return os_malloc_aligned(size, alignment);
}


static void
llvmpipe_free_memory(struct pipe_screen *screen,
                     struct pipe_memory_allocation *pmem)
{
   os_free_aligned(pmem);
}


#ifdef PIPE_MEMORY_FD

static const char *driver_id = "llvmpipe" MESA_GIT_SHA1;


static struct pipe_memory_allocation *
llvmpipe_allocate_memory_fd(struct pipe_screen *screen,
                            uint64_t size,
                            int *fd)
{
   uint64_t alignment;
   if (!os_get_page_size(&alignment))
      alignment = 256;
   return os_malloc_aligned_fd(size, alignment, fd,
                               "llvmpipe memory fd", driver_id);
}


static bool
llvmpipe_import_memory_fd(struct pipe_screen *screen,
                          int fd,
                          struct pipe_memory_allocation **ptr,
                          uint64_t *size)
{
   return os_import_memory_fd(fd, (void**)ptr, size, driver_id);
}


static void
llvmpipe_free_memory_fd(struct pipe_screen *screen,
                        struct pipe_memory_allocation *pmem)
{
   os_free_fd(pmem);
}

#endif


static bool
llvmpipe_resource_bind_backing(struct pipe_screen *screen,
                               struct pipe_resource *pt,
                               struct pipe_memory_allocation *pmem,
                               uint64_t offset)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(pt);

   if (!lpr->backable)
      return false;

   if (llvmpipe_resource_is_texture(&lpr->base)) {
      if (lpr->size_required > LP_MAX_TEXTURE_SIZE)
         return false;

      lpr->tex_data = (char *)pmem + offset;
   } else
      lpr->data = (char *)pmem + offset;
   lpr->backing_offset = offset;

   return true;
}


static void *
llvmpipe_map_memory(struct pipe_screen *screen,
                    struct pipe_memory_allocation *pmem)
{
   return pmem;
}


static void
llvmpipe_unmap_memory(struct pipe_screen *screen,
                      struct pipe_memory_allocation *pmem)
{
}


#ifdef DEBUG
void
llvmpipe_print_resources(void)
{
   struct llvmpipe_resource *lpr;
   unsigned n = 0, total = 0;

   debug_printf("LLVMPIPE: current resources:\n");
   simple_mtx_lock(&resource_list_mutex);
   LIST_FOR_EACH_ENTRY(lpr, &resource_list.list, list) {
      unsigned size = llvmpipe_resource_size(&lpr->base);
      debug_printf("resource %u at %p, size %ux%ux%u: %u bytes, refcount %u\n",
                   lpr->id, (void *) lpr,
                   lpr->base.width0, lpr->base.height0, lpr->base.depth0,
                   size, lpr->base.reference.count);
      total += size;
      n++;
   }
   simple_mtx_unlock(&resource_list_mutex);
   debug_printf("LLVMPIPE: total size of %u resources: %u\n", n, total);
}
#endif


static void
llvmpipe_get_resource_info(struct pipe_screen *screen,
                           struct pipe_resource *resource,
                           unsigned *stride,
                           unsigned *offset)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);

   *stride = lpr->row_stride[0];
   *offset = 0;
}


static bool
llvmpipe_resource_get_param(struct pipe_screen *screen,
                            struct pipe_context *context,
                            struct pipe_resource *resource,
                            unsigned plane,
                            unsigned layer,
                            unsigned level,
                            enum pipe_resource_param param,
                            unsigned handle_usage,
                            uint64_t *value)
{
   struct llvmpipe_resource *lpr = llvmpipe_resource(resource);
   struct winsys_handle whandle;

   switch (param) {
   case PIPE_RESOURCE_PARAM_NPLANES:
      *value = 1;
      return true;
   case PIPE_RESOURCE_PARAM_STRIDE:
      *value = lpr->row_stride[level];
      return true;
   case PIPE_RESOURCE_PARAM_OFFSET:
      *value = lpr->mip_offsets[level] + (lpr->img_stride[level] * layer);
      return true;
   case PIPE_RESOURCE_PARAM_LAYER_STRIDE:
      *value = lpr->img_stride[level];
      return true;
#ifndef _WIN32
   case PIPE_RESOURCE_PARAM_MODIFIER:
      *value = DRM_FORMAT_MOD_INVALID;
      return true;
#endif
   case PIPE_RESOURCE_PARAM_HANDLE_TYPE_SHARED:
   case PIPE_RESOURCE_PARAM_HANDLE_TYPE_KMS:
   case PIPE_RESOURCE_PARAM_HANDLE_TYPE_FD:
      if (!lpr->dt)
         return false;

      memset(&whandle, 0, sizeof(whandle));
      if (param == PIPE_RESOURCE_PARAM_HANDLE_TYPE_SHARED)
         whandle.type = WINSYS_HANDLE_TYPE_SHARED;
      else if (param == PIPE_RESOURCE_PARAM_HANDLE_TYPE_KMS)
         whandle.type = WINSYS_HANDLE_TYPE_KMS;
      else if (param == PIPE_RESOURCE_PARAM_HANDLE_TYPE_FD)
         whandle.type = WINSYS_HANDLE_TYPE_FD;

      if (!llvmpipe_resource_get_handle(screen, context, resource,
                                        &whandle, handle_usage)) {
         return false;
      }
      *value = (uint64_t)(uintptr_t)whandle.handle;
      return true;
   default:
      break;
   }
   assert(0);
   *value = 0;
   return false;
}


void
llvmpipe_init_screen_resource_funcs(struct pipe_screen *screen)
{
#ifdef DEBUG
   /* init linked list for tracking resources */
   {
      static bool first_call = true;
      if (first_call) {
         memset(&resource_list, 0, sizeof(resource_list));
         list_inithead(&resource_list.list);
         first_call = false;
      }
   }
#endif

   screen->resource_create = llvmpipe_resource_create;
/*   screen->resource_create_front = llvmpipe_resource_create_front; */
   screen->resource_destroy = llvmpipe_resource_destroy;
   screen->resource_from_handle = llvmpipe_resource_from_handle;
   screen->resource_from_memobj = llvmpipe_resource_from_memobj;
   screen->resource_get_handle = llvmpipe_resource_get_handle;
   screen->can_create_resource = llvmpipe_can_create_resource;

   screen->resource_create_unbacked = llvmpipe_resource_create_unbacked;

   screen->memobj_create_from_handle = llvmpipe_memobj_create_from_handle;
   screen->memobj_destroy = llvmpipe_memobj_destroy;

   screen->resource_get_info = llvmpipe_get_resource_info;
   screen->resource_get_param = llvmpipe_resource_get_param;
   screen->resource_from_user_memory = llvmpipe_resource_from_user_memory;
   screen->allocate_memory = llvmpipe_allocate_memory;
   screen->free_memory = llvmpipe_free_memory;
#ifdef PIPE_MEMORY_FD
   screen->allocate_memory_fd = llvmpipe_allocate_memory_fd;
   screen->import_memory_fd = llvmpipe_import_memory_fd;
   screen->free_memory_fd = llvmpipe_free_memory_fd;
#endif
   screen->map_memory = llvmpipe_map_memory;
   screen->unmap_memory = llvmpipe_unmap_memory;

   screen->resource_bind_backing = llvmpipe_resource_bind_backing;
}


void
llvmpipe_init_context_resource_funcs(struct pipe_context *pipe)
{
   pipe->buffer_map = llvmpipe_transfer_map;
   pipe->buffer_unmap = llvmpipe_transfer_unmap;
   pipe->texture_map = llvmpipe_transfer_map;
   pipe->texture_unmap = llvmpipe_transfer_unmap;

   pipe->transfer_flush_region = u_default_transfer_flush_region;
   pipe->buffer_subdata = u_default_buffer_subdata;
   pipe->texture_subdata = u_default_texture_subdata;

   pipe->memory_barrier = llvmpipe_memory_barrier;
}