src/gallium/drivers/svga/svga_resource_buffer_upload.c - platform/external/mesa3d - Git at Google

 /**********************************************************
  * Copyright 2008-2009 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, 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 AUTHORS OR COPYRIGHT HOLDERS
  * 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 "os/os_thread.h"
 #include "pipe/p_state.h"
 #include "pipe/p_defines.h"
 #include "util/u_inlines.h"
 #include "util/u_math.h"
 #include "util/u_memory.h"

 #include "svga_cmd.h"
 #include "svga_context.h"
 #include "svga_debug.h"
 #include "svga_resource_buffer.h"
 #include "svga_resource_buffer_upload.h"
 #include "svga_screen.h"
 #include "svga_winsys.h"


 /**
  * Allocate a winsys_buffer (ie. DMA, aka GMR memory).
  *
  * It will flush and retry in case the first attempt to create a DMA buffer
  * fails, so it should not be called from any function involved in flushing
  * to avoid recursion.
  */
 struct svga_winsys_buffer *
 svga_winsys_buffer_create( struct svga_context *svga,
                            unsigned alignment,
                            unsigned usage,
                            unsigned size )
 {
    struct svga_screen *svgascreen = svga_screen(svga->pipe.screen);
    struct svga_winsys_screen *sws = svgascreen->sws;
    struct svga_winsys_buffer *buf;

    /* Just try */
    buf = sws->buffer_create(sws, alignment, usage, size);
    if (!buf) {
       SVGA_DBG(DEBUG_DMA|DEBUG_PERF, "flushing context to find %d bytes GMR\n",
                size);

       /* Try flushing all pending DMAs */
       svga_context_flush(svga, NULL);
       buf = sws->buffer_create(sws, alignment, usage, size);
    }

    return buf;
 }


 void
 svga_buffer_destroy_hw_storage(struct svga_screen *ss, struct svga_buffer *sbuf)
 {
    struct svga_winsys_screen *sws = ss->sws;

    assert(!sbuf->map.count);
    assert(sbuf->hwbuf);
    if (sbuf->hwbuf) {
       sws->buffer_destroy(sws, sbuf->hwbuf);
       sbuf->hwbuf = NULL;
    }
 }


 /**
  * Allocate DMA'ble storage for the buffer.
  *
  * Called before mapping a buffer.
  */
 enum pipe_error
 svga_buffer_create_hw_storage(struct svga_screen *ss,
                               struct svga_buffer *sbuf)
 {
    assert(!sbuf->user);

    if (!sbuf->hwbuf) {
       struct svga_winsys_screen *sws = ss->sws;
       unsigned alignment = 16;
       unsigned usage = 0;
       unsigned size = sbuf->b.b.width0;

       sbuf->hwbuf = sws->buffer_create(sws, alignment, usage, size);
       if (!sbuf->hwbuf)
          return PIPE_ERROR_OUT_OF_MEMORY;

       assert(!sbuf->dma.pending);
    }

    return PIPE_OK;
 }


 enum pipe_error
 svga_buffer_create_host_surface(struct svga_screen *ss,
                                 struct svga_buffer *sbuf)
 {
    assert(!sbuf->user);

    if (!sbuf->handle) {
       sbuf->key.flags = 0;

       sbuf->key.format = SVGA3D_BUFFER;
       if (sbuf->b.b.bind & PIPE_BIND_VERTEX_BUFFER)
          sbuf->key.flags |= SVGA3D_SURFACE_HINT_VERTEXBUFFER;
       if (sbuf->b.b.bind & PIPE_BIND_INDEX_BUFFER)
          sbuf->key.flags |= SVGA3D_SURFACE_HINT_INDEXBUFFER;

       sbuf->key.size.width = sbuf->b.b.width0;
       sbuf->key.size.height = 1;
       sbuf->key.size.depth = 1;

       sbuf->key.numFaces = 1;
       sbuf->key.numMipLevels = 1;
       sbuf->key.cachable = 1;

       SVGA_DBG(DEBUG_DMA, "surface_create for buffer sz %d\n", sbuf->b.b.width0);

       sbuf->handle = svga_screen_surface_create(ss, &sbuf->key);
       if (!sbuf->handle)
          return PIPE_ERROR_OUT_OF_MEMORY;

       /* Always set the discard flag on the first time the buffer is written
        * as svga_screen_surface_create might have passed a recycled host
        * buffer.
        */
       sbuf->dma.flags.discard = TRUE;

       SVGA_DBG(DEBUG_DMA, "   --> got sid %p sz %d (buffer)\n", sbuf->handle, sbuf->b.b.width0);
    }

    return PIPE_OK;
 }


 void
 svga_buffer_destroy_host_surface(struct svga_screen *ss,
                                  struct svga_buffer *sbuf)
 {
    if (sbuf->handle) {
       SVGA_DBG(DEBUG_DMA, " ungrab sid %p sz %d\n", sbuf->handle, sbuf->b.b.width0);
       svga_screen_surface_destroy(ss, &sbuf->key, &sbuf->handle);
    }
 }


 /**
  * Variant of SVGA3D_BufferDMA which leaves the copy box temporarily in blank.
  */
 static enum pipe_error
 svga_buffer_upload_command(struct svga_context *svga,
                            struct svga_buffer *sbuf)
 {
    struct svga_winsys_context *swc = svga->swc;
    struct svga_winsys_buffer *guest = sbuf->hwbuf;
    struct svga_winsys_surface *host = sbuf->handle;
    SVGA3dTransferType transfer = SVGA3D_WRITE_HOST_VRAM;
    SVGA3dCmdSurfaceDMA *cmd;
    uint32 numBoxes = sbuf->map.num_ranges;
    SVGA3dCopyBox *boxes;
    SVGA3dCmdSurfaceDMASuffix *pSuffix;
    unsigned region_flags;
    unsigned surface_flags;
    struct pipe_resource *dummy;

    if (transfer == SVGA3D_WRITE_HOST_VRAM) {
       region_flags = SVGA_RELOC_READ;
       surface_flags = SVGA_RELOC_WRITE;
    }
    else if (transfer == SVGA3D_READ_HOST_VRAM) {
       region_flags = SVGA_RELOC_WRITE;
       surface_flags = SVGA_RELOC_READ;
    }
    else {
       assert(0);
       return PIPE_ERROR_BAD_INPUT;
    }

    assert(numBoxes);

    cmd = SVGA3D_FIFOReserve(swc,
                             SVGA_3D_CMD_SURFACE_DMA,
                             sizeof *cmd + numBoxes * sizeof *boxes + sizeof *pSuffix,
                             2);
    if (!cmd)
       return PIPE_ERROR_OUT_OF_MEMORY;

    swc->region_relocation(swc, &cmd->guest.ptr, guest, 0, region_flags);
    cmd->guest.pitch = 0;

    swc->surface_relocation(swc, &cmd->host.sid, host, surface_flags);
    cmd->host.face = 0;
    cmd->host.mipmap = 0;

    cmd->transfer = transfer;

    sbuf->dma.boxes = (SVGA3dCopyBox *)&cmd[1];
    sbuf->dma.svga = svga;

    /* Increment reference count */
    dummy = NULL;
    pipe_resource_reference(&dummy, &sbuf->b.b);

    pSuffix = (SVGA3dCmdSurfaceDMASuffix *)((uint8_t*)cmd + sizeof *cmd + numBoxes * sizeof *boxes);
    pSuffix->suffixSize = sizeof *pSuffix;
    pSuffix->maximumOffset = sbuf->b.b.width0;
    pSuffix->flags = sbuf->dma.flags;

    SVGA_FIFOCommitAll(swc);

    sbuf->dma.flags.discard = FALSE;

    return PIPE_OK;
 }


 /**
  * Patch up the upload DMA command reserved by svga_buffer_upload_command
  * with the final ranges.
  */
 void
 svga_buffer_upload_flush(struct svga_context *svga,
                          struct svga_buffer *sbuf)
 {
    SVGA3dCopyBox *boxes;
    unsigned i;
    struct pipe_resource *dummy;

    if (!sbuf->dma.pending) {
       return;
    }

    assert(sbuf->handle);
    assert(sbuf->hwbuf);
    assert(sbuf->map.num_ranges);
    assert(sbuf->dma.svga == svga);
    assert(sbuf->dma.boxes);

    /*
     * Patch the DMA command with the final copy box.
     */

    SVGA_DBG(DEBUG_DMA, "dma to sid %p\n", sbuf->handle);

    boxes = sbuf->dma.boxes;
    for (i = 0; i < sbuf->map.num_ranges; ++i) {
       SVGA_DBG(DEBUG_DMA, "  bytes %u - %u\n",
                sbuf->map.ranges[i].start, sbuf->map.ranges[i].end);

       boxes[i].x = sbuf->map.ranges[i].start;
       boxes[i].y = 0;
       boxes[i].z = 0;
       boxes[i].w = sbuf->map.ranges[i].end - sbuf->map.ranges[i].start;
       boxes[i].h = 1;
       boxes[i].d = 1;
       boxes[i].srcx = sbuf->map.ranges[i].start;
       boxes[i].srcy = 0;
       boxes[i].srcz = 0;
    }

    sbuf->map.num_ranges = 0;

    assert(sbuf->head.prev && sbuf->head.next);
    LIST_DEL(&sbuf->head);
 #ifdef DEBUG
    sbuf->head.next = sbuf->head.prev = NULL;
 #endif
    sbuf->dma.pending = FALSE;
    sbuf->dma.flags.discard = FALSE;
    sbuf->dma.flags.unsynchronized = FALSE;

    sbuf->dma.svga = NULL;
    sbuf->dma.boxes = NULL;

    /* Decrement reference count (and potentially destroy) */
    dummy = &sbuf->b.b;
    pipe_resource_reference(&dummy, NULL);
 }


 /**
  * Note a dirty range.
  *
  * This function only notes the range down. It doesn't actually emit a DMA
  * upload command. That only happens when a context tries to refer to this
  * buffer, and the DMA upload command is added to that context's command
  * buffer.
  *
  * We try to lump as many contiguous DMA transfers together as possible.
  */
 void
 svga_buffer_add_range(struct svga_buffer *sbuf,
                       unsigned start,
                       unsigned end)
 {
    unsigned i;
    unsigned nearest_range;
    unsigned nearest_dist;

    assert(end > start);

    if (sbuf->map.num_ranges < SVGA_BUFFER_MAX_RANGES) {
       nearest_range = sbuf->map.num_ranges;
       nearest_dist = ~0;
    } else {
       nearest_range = SVGA_BUFFER_MAX_RANGES - 1;
       nearest_dist = 0;
    }

    /*
     * Try to grow one of the ranges.
     */

    for (i = 0; i < sbuf->map.num_ranges; ++i) {
       int left_dist;
       int right_dist;
       int dist;

       left_dist = start - sbuf->map.ranges[i].end;
       right_dist = sbuf->map.ranges[i].start - end;
       dist = MAX2(left_dist, right_dist);

       if (dist <= 0) {
          /*
           * Ranges are contiguous or overlapping -- extend this one and return.
           *
           * Note that it is not this function's task to prevent overlapping
           * ranges, as the GMR was already given so it is too late to do
           * anything.  If the ranges overlap here it must surely be because
           * PIPE_TRANSFER_UNSYNCHRONIZED was set.
           */

          sbuf->map.ranges[i].start = MIN2(sbuf->map.ranges[i].start, start);
          sbuf->map.ranges[i].end   = MAX2(sbuf->map.ranges[i].end,   end);
          return;
       }
       else {
          /*
           * Discontiguous ranges -- keep track of the nearest range.
           */

          if (dist < nearest_dist) {
             nearest_range = i;
             nearest_dist = dist;
          }
       }
    }

    /*
     * We cannot add a new range to an existing DMA command, so patch-up the
     * pending DMA upload and start clean.
     */

    svga_buffer_upload_flush(sbuf->dma.svga, sbuf);

    assert(!sbuf->dma.pending);
    assert(!sbuf->dma.svga);
    assert(!sbuf->dma.boxes);

    if (sbuf->map.num_ranges < SVGA_BUFFER_MAX_RANGES) {
       /*
        * Add a new range.
        */

       sbuf->map.ranges[sbuf->map.num_ranges].start = start;
       sbuf->map.ranges[sbuf->map.num_ranges].end = end;
       ++sbuf->map.num_ranges;
    } else {
       /*
        * Everything else failed, so just extend the nearest range.
        *
        * It is OK to do this because we always keep a local copy of the
        * host buffer data, for SW TNL, and the host never modifies the buffer.
        */

       assert(nearest_range < SVGA_BUFFER_MAX_RANGES);
       assert(nearest_range < sbuf->map.num_ranges);
       sbuf->map.ranges[nearest_range].start = MIN2(sbuf->map.ranges[nearest_range].start, start);
       sbuf->map.ranges[nearest_range].end   = MAX2(sbuf->map.ranges[nearest_range].end,   end);
    }
 }


 /**
  * Copy the contents of the malloc buffer to a hardware buffer.
  */
 static enum pipe_error
 svga_buffer_update_hw(struct svga_screen *ss, struct svga_buffer *sbuf)
 {
    assert(!sbuf->user);
    if (!sbuf->hwbuf) {
       enum pipe_error ret;
       void *map;

       assert(sbuf->swbuf);
       if (!sbuf->swbuf)
          return PIPE_ERROR;

       ret = svga_buffer_create_hw_storage(ss, sbuf);
       if (ret != PIPE_OK)
          return ret;

       pipe_mutex_lock(ss->swc_mutex);
       map = ss->sws->buffer_map(ss->sws, sbuf->hwbuf, PIPE_TRANSFER_WRITE);
       assert(map);
       if (!map) {
 	 pipe_mutex_unlock(ss->swc_mutex);
          svga_buffer_destroy_hw_storage(ss, sbuf);
          return PIPE_ERROR;
       }

       memcpy(map, sbuf->swbuf, sbuf->b.b.width0);
       ss->sws->buffer_unmap(ss->sws, sbuf->hwbuf);

       /* This user/malloc buffer is now indistinguishable from a gpu buffer */
       assert(!sbuf->map.count);
       if (!sbuf->map.count) {
          if (sbuf->user)
             sbuf->user = FALSE;
          else
             align_free(sbuf->swbuf);
          sbuf->swbuf = NULL;
       }

       pipe_mutex_unlock(ss->swc_mutex);
    }

    return PIPE_OK;
 }


 /**
  * Upload the buffer to the host in a piecewise fashion.
  *
  * Used when the buffer is too big to fit in the GMR aperture.
  */
 static enum pipe_error
 svga_buffer_upload_piecewise(struct svga_screen *ss,
                              struct svga_context *svga,
                              struct svga_buffer *sbuf)
 {
    struct svga_winsys_screen *sws = ss->sws;
    const unsigned alignment = sizeof(void *);
    const unsigned usage = 0;
    unsigned i;

    assert(sbuf->map.num_ranges);
    assert(!sbuf->dma.pending);

    SVGA_DBG(DEBUG_DMA, "dma to sid %p\n", sbuf->handle);

    for (i = 0; i < sbuf->map.num_ranges; ++i) {
       struct svga_buffer_range *range = &sbuf->map.ranges[i];
       unsigned offset = range->start;
       unsigned size = range->end - range->start;

       while (offset < range->end) {
          struct svga_winsys_buffer *hwbuf;
          uint8_t *map;
          enum pipe_error ret;

          if (offset + size > range->end)
             size = range->end - offset;

          hwbuf = sws->buffer_create(sws, alignment, usage, size);
          while (!hwbuf) {
             size /= 2;
             if (!size)
                return PIPE_ERROR_OUT_OF_MEMORY;
             hwbuf = sws->buffer_create(sws, alignment, usage, size);
          }

          SVGA_DBG(DEBUG_DMA, "  bytes %u - %u\n",
                   offset, offset + size);

          map = sws->buffer_map(sws, hwbuf,
                                PIPE_TRANSFER_WRITE |
                                PIPE_TRANSFER_DISCARD_RANGE);
          assert(map);
          if (map) {
             memcpy(map, sbuf->swbuf, size);
             sws->buffer_unmap(sws, hwbuf);
          }

          ret = SVGA3D_BufferDMA(svga->swc,
                                 hwbuf, sbuf->handle,
                                 SVGA3D_WRITE_HOST_VRAM,
                                 size, 0, offset, sbuf->dma.flags);
          if (ret != PIPE_OK) {
             svga_context_flush(svga, NULL);
             ret =  SVGA3D_BufferDMA(svga->swc,
                                     hwbuf, sbuf->handle,
                                     SVGA3D_WRITE_HOST_VRAM,
                                     size, 0, offset, sbuf->dma.flags);
             assert(ret == PIPE_OK);
          }

          sbuf->dma.flags.discard = FALSE;

          sws->buffer_destroy(sws, hwbuf);

          offset += size;
       }
    }

    sbuf->map.num_ranges = 0;

    return PIPE_OK;
 }


 /* Get (or create/upload) the winsys surface handle so that we can
  * refer to this buffer in fifo commands.
  */
 struct svga_winsys_surface *
 svga_buffer_handle(struct svga_context *svga,
                    struct pipe_resource *buf)
 {
    struct pipe_screen *screen = svga->pipe.screen;
    struct svga_screen *ss = svga_screen(screen);
    struct svga_buffer *sbuf;
    enum pipe_error ret;

    if (!buf)
       return NULL;

    sbuf = svga_buffer(buf);

    assert(!sbuf->map.count);
    assert(!sbuf->user);

    if (!sbuf->handle) {
       ret = svga_buffer_create_host_surface(ss, sbuf);
       if (ret != PIPE_OK)
 	 return NULL;
    }

    assert(sbuf->handle);

    if (sbuf->map.num_ranges) {
       if (!sbuf->dma.pending) {
          /*
           * No pending DMA upload yet, so insert a DMA upload command now.
           */

          /*
           * Migrate the data from swbuf -> hwbuf if necessary.
           */
          ret = svga_buffer_update_hw(ss, sbuf);
          if (ret == PIPE_OK) {
             /*
              * Queue a dma command.
              */

             ret = svga_buffer_upload_command(svga, sbuf);
             if (ret == PIPE_ERROR_OUT_OF_MEMORY) {
                svga_context_flush(svga, NULL);
                ret = svga_buffer_upload_command(svga, sbuf);
                assert(ret == PIPE_OK);
             }
             if (ret == PIPE_OK) {
                sbuf->dma.pending = TRUE;
                assert(!sbuf->head.prev && !sbuf->head.next);
                LIST_ADDTAIL(&sbuf->head, &svga->dirty_buffers);
             }
          }
          else if (ret == PIPE_ERROR_OUT_OF_MEMORY) {
             /*
              * The buffer is too big to fit in the GMR aperture, so break it in
              * smaller pieces.
              */
             ret = svga_buffer_upload_piecewise(ss, svga, sbuf);
          }

          if (ret != PIPE_OK) {
             /*
              * Something unexpected happened above. There is very little that
              * we can do other than proceeding while ignoring the dirty ranges.
              */
             assert(0);
             sbuf->map.num_ranges = 0;
          }
       }
       else {
          /*
           * There a pending dma already. Make sure it is from this context.
           */
          assert(sbuf->dma.svga == svga);
       }
    }

    assert(!sbuf->map.num_ranges || sbuf->dma.pending);

    return sbuf->handle;
 }


 void
 svga_context_flush_buffers(struct svga_context *svga)
 {
    struct list_head *curr, *next;
    struct svga_buffer *sbuf;

    curr = svga->dirty_buffers.next;
    next = curr->next;
    while(curr != &svga->dirty_buffers) {
       sbuf = LIST_ENTRY(struct svga_buffer, curr, head);

       assert(p_atomic_read(&sbuf->b.b.reference.count) != 0);
       assert(sbuf->dma.pending);

       svga_buffer_upload_flush(svga, sbuf);

       curr = next;
       next = curr->next;
    }
 }
	/**********************************************************
	* Copyright 2008-2009 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, 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 AUTHORS OR COPYRIGHT HOLDERS
	* 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 "os/os_thread.h"
	#include "pipe/p_state.h"
	#include "pipe/p_defines.h"
	#include "util/u_inlines.h"
	#include "util/u_math.h"
	#include "util/u_memory.h"

	#include "svga_cmd.h"
	#include "svga_context.h"
	#include "svga_debug.h"
	#include "svga_resource_buffer.h"
	#include "svga_resource_buffer_upload.h"
	#include "svga_screen.h"
	#include "svga_winsys.h"


	/**
	* Allocate a winsys_buffer (ie. DMA, aka GMR memory).
	*
	* It will flush and retry in case the first attempt to create a DMA buffer
	* fails, so it should not be called from any function involved in flushing
	* to avoid recursion.
	*/
	struct svga_winsys_buffer *
	svga_winsys_buffer_create( struct svga_context *svga,
	unsigned alignment,
	unsigned usage,
	unsigned size )
	{
	struct svga_screen *svgascreen = svga_screen(svga->pipe.screen);
	struct svga_winsys_screen *sws = svgascreen->sws;
	struct svga_winsys_buffer *buf;

	/* Just try */
	buf = sws->buffer_create(sws, alignment, usage, size);
	if (!buf) {
	SVGA_DBG(DEBUG_DMA\|DEBUG_PERF, "flushing context to find %d bytes GMR\n",
	size);

	/* Try flushing all pending DMAs */
	svga_context_flush(svga, NULL);
	buf = sws->buffer_create(sws, alignment, usage, size);
	}

	return buf;
	}


	void
	svga_buffer_destroy_hw_storage(struct svga_screen ss, struct svga_buffer sbuf)
	{
	struct svga_winsys_screen *sws = ss->sws;

	assert(!sbuf->map.count);
	assert(sbuf->hwbuf);
	if (sbuf->hwbuf) {
	sws->buffer_destroy(sws, sbuf->hwbuf);
	sbuf->hwbuf = NULL;
	}
	}



	/**
	* Allocate DMA'ble storage for the buffer.
	*
	* Called before mapping a buffer.
	*/
	enum pipe_error
	svga_buffer_create_hw_storage(struct svga_screen *ss,
	struct svga_buffer *sbuf)
	{
	assert(!sbuf->user);

	if (!sbuf->hwbuf) {
	struct svga_winsys_screen *sws = ss->sws;
	unsigned alignment = 16;
	unsigned usage = 0;
	unsigned size = sbuf->b.b.width0;

	sbuf->hwbuf = sws->buffer_create(sws, alignment, usage, size);
	if (!sbuf->hwbuf)
	return PIPE_ERROR_OUT_OF_MEMORY;

	assert(!sbuf->dma.pending);
	}

	return PIPE_OK;
	}



	enum pipe_error
	svga_buffer_create_host_surface(struct svga_screen *ss,
	struct svga_buffer *sbuf)
	{
	assert(!sbuf->user);

	if (!sbuf->handle) {
	sbuf->key.flags = 0;

	sbuf->key.format = SVGA3D_BUFFER;
	if (sbuf->b.b.bind & PIPE_BIND_VERTEX_BUFFER)
	sbuf->key.flags \|= SVGA3D_SURFACE_HINT_VERTEXBUFFER;
	if (sbuf->b.b.bind & PIPE_BIND_INDEX_BUFFER)
	sbuf->key.flags \|= SVGA3D_SURFACE_HINT_INDEXBUFFER;

	sbuf->key.size.width = sbuf->b.b.width0;
	sbuf->key.size.height = 1;
	sbuf->key.size.depth = 1;

	sbuf->key.numFaces = 1;
	sbuf->key.numMipLevels = 1;
	sbuf->key.cachable = 1;

	SVGA_DBG(DEBUG_DMA, "surface_create for buffer sz %d\n", sbuf->b.b.width0);

	sbuf->handle = svga_screen_surface_create(ss, &sbuf->key);
	if (!sbuf->handle)
	return PIPE_ERROR_OUT_OF_MEMORY;

	/* Always set the discard flag on the first time the buffer is written
	* as svga_screen_surface_create might have passed a recycled host
	* buffer.
	*/
	sbuf->dma.flags.discard = TRUE;

	SVGA_DBG(DEBUG_DMA, " --> got sid %p sz %d (buffer)\n", sbuf->handle, sbuf->b.b.width0);
	}

	return PIPE_OK;
	}


	void
	svga_buffer_destroy_host_surface(struct svga_screen *ss,
	struct svga_buffer *sbuf)
	{
	if (sbuf->handle) {
	SVGA_DBG(DEBUG_DMA, " ungrab sid %p sz %d\n", sbuf->handle, sbuf->b.b.width0);
	svga_screen_surface_destroy(ss, &sbuf->key, &sbuf->handle);
	}
	}


	/**
	* Variant of SVGA3D_BufferDMA which leaves the copy box temporarily in blank.
	*/
	static enum pipe_error
	svga_buffer_upload_command(struct svga_context *svga,
	struct svga_buffer *sbuf)
	{
	struct svga_winsys_context *swc = svga->swc;
	struct svga_winsys_buffer *guest = sbuf->hwbuf;
	struct svga_winsys_surface *host = sbuf->handle;
	SVGA3dTransferType transfer = SVGA3D_WRITE_HOST_VRAM;
	SVGA3dCmdSurfaceDMA *cmd;
	uint32 numBoxes = sbuf->map.num_ranges;
	SVGA3dCopyBox *boxes;
	SVGA3dCmdSurfaceDMASuffix *pSuffix;
	unsigned region_flags;
	unsigned surface_flags;
	struct pipe_resource *dummy;

	if (transfer == SVGA3D_WRITE_HOST_VRAM) {
	region_flags = SVGA_RELOC_READ;
	surface_flags = SVGA_RELOC_WRITE;
	}
	else if (transfer == SVGA3D_READ_HOST_VRAM) {
	region_flags = SVGA_RELOC_WRITE;
	surface_flags = SVGA_RELOC_READ;
	}
	else {
	assert(0);
	return PIPE_ERROR_BAD_INPUT;
	}

	assert(numBoxes);

	cmd = SVGA3D_FIFOReserve(swc,
	SVGA_3D_CMD_SURFACE_DMA,
	sizeof cmd + numBoxes sizeof boxes + sizeof pSuffix,
	2);
	if (!cmd)
	return PIPE_ERROR_OUT_OF_MEMORY;

	swc->region_relocation(swc, &cmd->guest.ptr, guest, 0, region_flags);
	cmd->guest.pitch = 0;

	swc->surface_relocation(swc, &cmd->host.sid, host, surface_flags);
	cmd->host.face = 0;
	cmd->host.mipmap = 0;

	cmd->transfer = transfer;

	sbuf->dma.boxes = (SVGA3dCopyBox *)&cmd[1];
	sbuf->dma.svga = svga;

	/* Increment reference count */
	dummy = NULL;
	pipe_resource_reference(&dummy, &sbuf->b.b);

	pSuffix = (SVGA3dCmdSurfaceDMASuffix )((uint8_t)cmd + sizeof cmd + numBoxes sizeof *boxes);
	pSuffix->suffixSize = sizeof *pSuffix;
	pSuffix->maximumOffset = sbuf->b.b.width0;
	pSuffix->flags = sbuf->dma.flags;

	SVGA_FIFOCommitAll(swc);

	sbuf->dma.flags.discard = FALSE;

	return PIPE_OK;
	}


	/**
	* Patch up the upload DMA command reserved by svga_buffer_upload_command
	* with the final ranges.
	*/
	void
	svga_buffer_upload_flush(struct svga_context *svga,
	struct svga_buffer *sbuf)
	{
	SVGA3dCopyBox *boxes;
	unsigned i;
	struct pipe_resource *dummy;

	if (!sbuf->dma.pending) {
	return;
	}

	assert(sbuf->handle);
	assert(sbuf->hwbuf);
	assert(sbuf->map.num_ranges);
	assert(sbuf->dma.svga == svga);
	assert(sbuf->dma.boxes);

	/*
	* Patch the DMA command with the final copy box.
	*/

	SVGA_DBG(DEBUG_DMA, "dma to sid %p\n", sbuf->handle);

	boxes = sbuf->dma.boxes;
	for (i = 0; i < sbuf->map.num_ranges; ++i) {
	SVGA_DBG(DEBUG_DMA, " bytes %u - %u\n",
	sbuf->map.ranges[i].start, sbuf->map.ranges[i].end);

	boxes[i].x = sbuf->map.ranges[i].start;
	boxes[i].y = 0;
	boxes[i].z = 0;
	boxes[i].w = sbuf->map.ranges[i].end - sbuf->map.ranges[i].start;
	boxes[i].h = 1;
	boxes[i].d = 1;
	boxes[i].srcx = sbuf->map.ranges[i].start;
	boxes[i].srcy = 0;
	boxes[i].srcz = 0;
	}

	sbuf->map.num_ranges = 0;

	assert(sbuf->head.prev && sbuf->head.next);
	LIST_DEL(&sbuf->head);
	#ifdef DEBUG
	sbuf->head.next = sbuf->head.prev = NULL;
	#endif
	sbuf->dma.pending = FALSE;
	sbuf->dma.flags.discard = FALSE;
	sbuf->dma.flags.unsynchronized = FALSE;

	sbuf->dma.svga = NULL;
	sbuf->dma.boxes = NULL;

	/* Decrement reference count (and potentially destroy) */
	dummy = &sbuf->b.b;
	pipe_resource_reference(&dummy, NULL);
	}


	/**
	* Note a dirty range.
	*
	* This function only notes the range down. It doesn't actually emit a DMA
	* upload command. That only happens when a context tries to refer to this
	* buffer, and the DMA upload command is added to that context's command
	* buffer.
	*
	* We try to lump as many contiguous DMA transfers together as possible.
	*/
	void
	svga_buffer_add_range(struct svga_buffer *sbuf,
	unsigned start,
	unsigned end)
	{
	unsigned i;
	unsigned nearest_range;
	unsigned nearest_dist;

	assert(end > start);

	if (sbuf->map.num_ranges < SVGA_BUFFER_MAX_RANGES) {
	nearest_range = sbuf->map.num_ranges;
	nearest_dist = ~0;
	} else {
	nearest_range = SVGA_BUFFER_MAX_RANGES - 1;
	nearest_dist = 0;
	}

	/*
	* Try to grow one of the ranges.
	*/

	for (i = 0; i < sbuf->map.num_ranges; ++i) {
	int left_dist;
	int right_dist;
	int dist;

	left_dist = start - sbuf->map.ranges[i].end;
	right_dist = sbuf->map.ranges[i].start - end;
	dist = MAX2(left_dist, right_dist);

	if (dist <= 0) {
	/*
	* Ranges are contiguous or overlapping -- extend this one and return.
	*
	* Note that it is not this function's task to prevent overlapping
	* ranges, as the GMR was already given so it is too late to do
	* anything. If the ranges overlap here it must surely be because
	* PIPE_TRANSFER_UNSYNCHRONIZED was set.
	*/

	sbuf->map.ranges[i].start = MIN2(sbuf->map.ranges[i].start, start);
	sbuf->map.ranges[i].end = MAX2(sbuf->map.ranges[i].end, end);
	return;
	}
	else {
	/*
	* Discontiguous ranges -- keep track of the nearest range.
	*/

	if (dist < nearest_dist) {
	nearest_range = i;
	nearest_dist = dist;
	}
	}
	}

	/*
	* We cannot add a new range to an existing DMA command, so patch-up the
	* pending DMA upload and start clean.
	*/

	svga_buffer_upload_flush(sbuf->dma.svga, sbuf);

	assert(!sbuf->dma.pending);
	assert(!sbuf->dma.svga);
	assert(!sbuf->dma.boxes);

	if (sbuf->map.num_ranges < SVGA_BUFFER_MAX_RANGES) {
	/*
	* Add a new range.
	*/

	sbuf->map.ranges[sbuf->map.num_ranges].start = start;
	sbuf->map.ranges[sbuf->map.num_ranges].end = end;
	++sbuf->map.num_ranges;
	} else {
	/*
	* Everything else failed, so just extend the nearest range.
	*
	* It is OK to do this because we always keep a local copy of the
	* host buffer data, for SW TNL, and the host never modifies the buffer.
	*/

	assert(nearest_range < SVGA_BUFFER_MAX_RANGES);
	assert(nearest_range < sbuf->map.num_ranges);
	sbuf->map.ranges[nearest_range].start = MIN2(sbuf->map.ranges[nearest_range].start, start);
	sbuf->map.ranges[nearest_range].end = MAX2(sbuf->map.ranges[nearest_range].end, end);
	}
	}



	/**
	* Copy the contents of the malloc buffer to a hardware buffer.
	*/
	static enum pipe_error
	svga_buffer_update_hw(struct svga_screen ss, struct svga_buffer sbuf)
	{
	assert(!sbuf->user);
	if (!sbuf->hwbuf) {
	enum pipe_error ret;
	void *map;

	assert(sbuf->swbuf);
	if (!sbuf->swbuf)
	return PIPE_ERROR;

	ret = svga_buffer_create_hw_storage(ss, sbuf);
	if (ret != PIPE_OK)
	return ret;

	pipe_mutex_lock(ss->swc_mutex);
	map = ss->sws->buffer_map(ss->sws, sbuf->hwbuf, PIPE_TRANSFER_WRITE);
	assert(map);
	if (!map) {
	pipe_mutex_unlock(ss->swc_mutex);
	svga_buffer_destroy_hw_storage(ss, sbuf);
	return PIPE_ERROR;
	}

	memcpy(map, sbuf->swbuf, sbuf->b.b.width0);
	ss->sws->buffer_unmap(ss->sws, sbuf->hwbuf);

	/* This user/malloc buffer is now indistinguishable from a gpu buffer */
	assert(!sbuf->map.count);
	if (!sbuf->map.count) {
	if (sbuf->user)
	sbuf->user = FALSE;
	else
	align_free(sbuf->swbuf);
	sbuf->swbuf = NULL;
	}

	pipe_mutex_unlock(ss->swc_mutex);
	}

	return PIPE_OK;
	}


	/**
	* Upload the buffer to the host in a piecewise fashion.
	*
	* Used when the buffer is too big to fit in the GMR aperture.
	*/
	static enum pipe_error
	svga_buffer_upload_piecewise(struct svga_screen *ss,
	struct svga_context *svga,
	struct svga_buffer *sbuf)
	{
	struct svga_winsys_screen *sws = ss->sws;
	const unsigned alignment = sizeof(void *);
	const unsigned usage = 0;
	unsigned i;

	assert(sbuf->map.num_ranges);
	assert(!sbuf->dma.pending);

	SVGA_DBG(DEBUG_DMA, "dma to sid %p\n", sbuf->handle);

	for (i = 0; i < sbuf->map.num_ranges; ++i) {
	struct svga_buffer_range *range = &sbuf->map.ranges[i];
	unsigned offset = range->start;
	unsigned size = range->end - range->start;

	while (offset < range->end) {
	struct svga_winsys_buffer *hwbuf;
	uint8_t *map;
	enum pipe_error ret;

	if (offset + size > range->end)
	size = range->end - offset;

	hwbuf = sws->buffer_create(sws, alignment, usage, size);
	while (!hwbuf) {
	size /= 2;
	if (!size)
	return PIPE_ERROR_OUT_OF_MEMORY;
	hwbuf = sws->buffer_create(sws, alignment, usage, size);
	}

	SVGA_DBG(DEBUG_DMA, " bytes %u - %u\n",
	offset, offset + size);

	map = sws->buffer_map(sws, hwbuf,
	PIPE_TRANSFER_WRITE \|
	PIPE_TRANSFER_DISCARD_RANGE);
	assert(map);
	if (map) {
	memcpy(map, sbuf->swbuf, size);
	sws->buffer_unmap(sws, hwbuf);
	}

	ret = SVGA3D_BufferDMA(svga->swc,
	hwbuf, sbuf->handle,
	SVGA3D_WRITE_HOST_VRAM,
	size, 0, offset, sbuf->dma.flags);
	if (ret != PIPE_OK) {
	svga_context_flush(svga, NULL);
	ret = SVGA3D_BufferDMA(svga->swc,
	hwbuf, sbuf->handle,
	SVGA3D_WRITE_HOST_VRAM,
	size, 0, offset, sbuf->dma.flags);
	assert(ret == PIPE_OK);
	}

	sbuf->dma.flags.discard = FALSE;

	sws->buffer_destroy(sws, hwbuf);

	offset += size;
	}
	}

	sbuf->map.num_ranges = 0;

	return PIPE_OK;
	}




	/* Get (or create/upload) the winsys surface handle so that we can
	* refer to this buffer in fifo commands.
	*/
	struct svga_winsys_surface *
	svga_buffer_handle(struct svga_context *svga,
	struct pipe_resource *buf)
	{
	struct pipe_screen *screen = svga->pipe.screen;
	struct svga_screen *ss = svga_screen(screen);
	struct svga_buffer *sbuf;
	enum pipe_error ret;

	if (!buf)
	return NULL;

	sbuf = svga_buffer(buf);

	assert(!sbuf->map.count);
	assert(!sbuf->user);

	if (!sbuf->handle) {
	ret = svga_buffer_create_host_surface(ss, sbuf);
	if (ret != PIPE_OK)
	return NULL;
	}

	assert(sbuf->handle);

	if (sbuf->map.num_ranges) {
	if (!sbuf->dma.pending) {
	/*
	* No pending DMA upload yet, so insert a DMA upload command now.
	*/

	/*
	* Migrate the data from swbuf -> hwbuf if necessary.
	*/
	ret = svga_buffer_update_hw(ss, sbuf);
	if (ret == PIPE_OK) {
	/*
	* Queue a dma command.
	*/

	ret = svga_buffer_upload_command(svga, sbuf);
	if (ret == PIPE_ERROR_OUT_OF_MEMORY) {
	svga_context_flush(svga, NULL);
	ret = svga_buffer_upload_command(svga, sbuf);
	assert(ret == PIPE_OK);
	}
	if (ret == PIPE_OK) {
	sbuf->dma.pending = TRUE;
	assert(!sbuf->head.prev && !sbuf->head.next);
	LIST_ADDTAIL(&sbuf->head, &svga->dirty_buffers);
	}
	}
	else if (ret == PIPE_ERROR_OUT_OF_MEMORY) {
	/*
	* The buffer is too big to fit in the GMR aperture, so break it in
	* smaller pieces.
	*/
	ret = svga_buffer_upload_piecewise(ss, svga, sbuf);
	}

	if (ret != PIPE_OK) {
	/*
	* Something unexpected happened above. There is very little that
	* we can do other than proceeding while ignoring the dirty ranges.
	*/
	assert(0);
	sbuf->map.num_ranges = 0;
	}
	}
	else {
	/*
	* There a pending dma already. Make sure it is from this context.
	*/
	assert(sbuf->dma.svga == svga);
	}
	}

	assert(!sbuf->map.num_ranges \|\| sbuf->dma.pending);

	return sbuf->handle;
	}



	void
	svga_context_flush_buffers(struct svga_context *svga)
	{
	struct list_head curr, next;
	struct svga_buffer *sbuf;

	curr = svga->dirty_buffers.next;
	next = curr->next;
	while(curr != &svga->dirty_buffers) {
	sbuf = LIST_ENTRY(struct svga_buffer, curr, head);

	assert(p_atomic_read(&sbuf->b.b.reference.count) != 0);
	assert(sbuf->dma.pending);

	svga_buffer_upload_flush(svga, sbuf);

	curr = next;
	next = curr->next;
	}
	}