svga/drm/vmw_context.c

/*
 * Copyright (c) 2009-2024 Broadcom. All Rights Reserved.
 * The term “Broadcom” refers to Broadcom Inc.
 * and/or its subsidiaries.
 * SPDX-License-Identifier: MIT
 */


#include "svga_cmd.h"

#include "util/u_debug.h"
#include "util/u_memory.h"
#include "util/u_debug_stack.h"
#include "util/u_debug_flush.h"
#include "util/u_hash_table.h"
#include "util/u_bitmask.h"
#include "util/u_atomic.h"
#include "pipebuffer/pb_buffer.h"
#include "pipebuffer/pb_validate.h"

#include "svga_winsys.h"
#include "vmw_context.h"
#include "vmw_screen.h"
#include "vmw_buffer.h"
#include "vmw_surface.h"
#include "vmw_fence.h"
#include "vmw_shader.h"
#include "vmw_query.h"

#define VMW_COMMAND_SIZE (64*1024)
#define VMW_SURFACE_RELOCS (1024)
#define VMW_SHADER_RELOCS (1024)
#define VMW_REGION_RELOCS (512)

#define VMW_MUST_FLUSH_STACK 8

/*
 * A factor applied to the maximum mob memory size to determine
 * the optimial time to preemptively flush the command buffer.
 * The constant is based on some performance trials with SpecViewperf.
 */
#define VMW_MAX_MOB_MEM_FACTOR  2

/*
 * A factor applied to the maximum surface memory size to determine
 * the optimial time to preemptively flush the command buffer.
 * The constant is based on some performance trials with SpecViewperf.
 */
#define VMW_MAX_SURF_MEM_FACTOR 2


struct vmw_buffer_relocation
{
   struct pb_buffer *buffer;
   bool is_mob;
   uint32 offset;

   union {
      struct {
	 struct SVGAGuestPtr *where;
      } region;
      struct {
	 SVGAMobId *id;
	 uint32 *offset_into_mob;
      } mob;
   };
};

struct vmw_ctx_validate_item {
   union {
      struct vmw_svga_winsys_surface *vsurf;
      struct vmw_svga_winsys_shader *vshader;
   };
   bool referenced;
};

struct vmw_svga_winsys_context
{
   struct svga_winsys_context base;

   struct vmw_winsys_screen *vws;
   struct hash_table *hash;

#if MESA_DEBUG
   bool must_flush;
   struct debug_stack_frame must_flush_stack[VMW_MUST_FLUSH_STACK];
   struct debug_flush_ctx *fctx;
#endif

   struct {
      uint8_t buffer[VMW_COMMAND_SIZE];
      uint32_t size;
      uint32_t used;
      uint32_t reserved;
   } command;

   struct {
      struct vmw_ctx_validate_item items[VMW_SURFACE_RELOCS];
      uint32_t size;
      uint32_t used;
      uint32_t staged;
      uint32_t reserved;
   } surface;

   struct {
      struct vmw_buffer_relocation relocs[VMW_REGION_RELOCS];
      uint32_t size;
      uint32_t used;
      uint32_t staged;
      uint32_t reserved;
   } region;

   struct {
      struct vmw_ctx_validate_item items[VMW_SHADER_RELOCS];
      uint32_t size;
      uint32_t used;
      uint32_t staged;
      uint32_t reserved;
   } shader;

   struct pb_validate *validate;

   /**
    * The amount of surface, GMR or MOB memory that is referred by the commands
    * currently batched in the context command buffer.
    */
   uint64_t seen_surfaces;
   uint64_t seen_regions;
   uint64_t seen_mobs;

   int32_t refcount;

   /* Bitmask of userspace managed surfaces */
   struct util_bitmask *surface_id_bm;

   /**
    * Whether this context should fail to reserve more commands, not because it
    * ran out of command space, but because a substantial ammount of GMR was
    * referred.
    */
   bool preemptive_flush;
};


static inline struct vmw_svga_winsys_context *
vmw_svga_winsys_context(struct svga_winsys_context *swc)
{
   assert(swc);
   return (struct vmw_svga_winsys_context *)swc;
}


static inline enum pb_usage_flags
vmw_translate_to_pb_flags(unsigned flags)
{
   enum pb_usage_flags f = 0;
   if (flags & SVGA_RELOC_READ)
      f |= PB_USAGE_GPU_READ;

   if (flags & SVGA_RELOC_WRITE)
      f |= PB_USAGE_GPU_WRITE;

   return f;
}

static enum pipe_error
vmw_swc_flush(struct svga_winsys_context *swc,
              struct pipe_fence_handle **pfence)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_winsys_screen *vws = vswc->vws;
   struct pipe_fence_handle *fence = NULL;
   unsigned i;
   enum pipe_error ret;

   /*
    * If we hit a retry, lock the mutex and retry immediately.
    * If we then still hit a retry, sleep until another thread
    * wakes us up after it has released its buffers from the
    * validate list.
    *
    * If we hit another error condition, we still need to broadcast since
    * pb_validate_validate releases validated buffers in its error path.
    */

   ret = pb_validate_validate(vswc->validate);
   if (ret != PIPE_OK) {
      mtx_lock(&vws->cs_mutex);
      while (ret == PIPE_ERROR_RETRY) {
         ret = pb_validate_validate(vswc->validate);
         if (ret == PIPE_ERROR_RETRY) {
            cnd_wait(&vws->cs_cond, &vws->cs_mutex);
         }
      }
      if (ret != PIPE_OK) {
         cnd_broadcast(&vws->cs_cond);
      }
      mtx_unlock(&vws->cs_mutex);
   }

   assert(ret == PIPE_OK);
   if(ret == PIPE_OK) {

      /* Apply relocations */
      for(i = 0; i < vswc->region.used; ++i) {
         struct vmw_buffer_relocation *reloc = &vswc->region.relocs[i];
         struct SVGAGuestPtr ptr;

         if(!vmw_dma_bufmgr_region_ptr(reloc->buffer, &ptr))
            assert(0);

         ptr.offset += reloc->offset;

	 if (reloc->is_mob) {
	    if (reloc->mob.id)
	       *reloc->mob.id = ptr.gmrId;
	    if (reloc->mob.offset_into_mob)
	       *reloc->mob.offset_into_mob = ptr.offset;
	    else {
	       assert(ptr.offset == 0);
	    }
	 } else
	    *reloc->region.where = ptr;
      }

      if (vswc->command.used || pfence != NULL)
         vmw_ioctl_command(vws,
                           vswc->base.cid,
                           0,
                           vswc->command.buffer,
                           vswc->command.used,
                           &fence,
                           vswc->base.imported_fence_fd,
                           vswc->base.hints);

      pb_validate_fence(vswc->validate, fence);
      mtx_lock(&vws->cs_mutex);
      cnd_broadcast(&vws->cs_cond);
      mtx_unlock(&vws->cs_mutex);
   }

   vswc->command.used = 0;
   vswc->command.reserved = 0;

   for(i = 0; i < vswc->surface.used + vswc->surface.staged; ++i) {
      struct vmw_ctx_validate_item *isurf = &vswc->surface.items[i];
      if (isurf->referenced)
         p_atomic_dec(&isurf->vsurf->validated);
      vmw_svga_winsys_surface_reference(&isurf->vsurf, NULL);
   }

   _mesa_hash_table_clear(vswc->hash, NULL);
   vswc->surface.used = 0;
   vswc->surface.reserved = 0;

   for(i = 0; i < vswc->shader.used + vswc->shader.staged; ++i) {
      struct vmw_ctx_validate_item *ishader = &vswc->shader.items[i];
      if (ishader->referenced)
         p_atomic_dec(&ishader->vshader->validated);
      vmw_svga_winsys_shader_reference(&ishader->vshader, NULL);
   }

   vswc->shader.used = 0;
   vswc->shader.reserved = 0;

   vswc->region.used = 0;
   vswc->region.reserved = 0;

#if MESA_DEBUG
   vswc->must_flush = false;
   debug_flush_flush(vswc->fctx);
#endif
   swc->hints &= ~SVGA_HINT_FLAG_CAN_PRE_FLUSH;
   swc->hints &= ~SVGA_HINT_FLAG_EXPORT_FENCE_FD;
   vswc->preemptive_flush = false;
   vswc->seen_surfaces = 0;
   vswc->seen_regions = 0;
   vswc->seen_mobs = 0;

   if (vswc->base.imported_fence_fd != -1) {
      close(vswc->base.imported_fence_fd);
      vswc->base.imported_fence_fd = -1;
   }

   if(pfence)
      vmw_fence_reference(vswc->vws, pfence, fence);

   vmw_fence_reference(vswc->vws, &fence, NULL);

   return ret;
}


static void *
vmw_swc_reserve(struct svga_winsys_context *swc,
                uint32_t nr_bytes, uint32_t nr_relocs )
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);

#if MESA_DEBUG
   /* Check if somebody forgot to check the previous failure */
   if(vswc->must_flush) {
      debug_printf("Forgot to flush:\n");
      debug_backtrace_dump(vswc->must_flush_stack, VMW_MUST_FLUSH_STACK);
      assert(!vswc->must_flush);
   }
   debug_flush_might_flush(vswc->fctx);
#endif

   assert(nr_bytes <= vswc->command.size);
   if(nr_bytes > vswc->command.size)
      return NULL;

   if(vswc->preemptive_flush ||
      vswc->command.used + nr_bytes > vswc->command.size ||
      vswc->surface.used + nr_relocs > vswc->surface.size ||
      vswc->shader.used + nr_relocs > vswc->shader.size ||
      vswc->region.used + nr_relocs > vswc->region.size) {
#if MESA_DEBUG
      vswc->must_flush = true;
      debug_backtrace_capture(vswc->must_flush_stack, 1,
                              VMW_MUST_FLUSH_STACK);
#endif
      return NULL;
   }

   assert(vswc->command.used + nr_bytes <= vswc->command.size);
   assert(vswc->surface.used + nr_relocs <= vswc->surface.size);
   assert(vswc->shader.used + nr_relocs <= vswc->shader.size);
   assert(vswc->region.used + nr_relocs <= vswc->region.size);

   vswc->command.reserved = nr_bytes;
   vswc->surface.reserved = nr_relocs;
   vswc->surface.staged = 0;
   vswc->shader.reserved = nr_relocs;
   vswc->shader.staged = 0;
   vswc->region.reserved = nr_relocs;
   vswc->region.staged = 0;

   return vswc->command.buffer + vswc->command.used;
}

static unsigned
vmw_swc_get_command_buffer_size(struct svga_winsys_context *swc)
{
   const struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   return vswc->command.used;
}

static void
vmw_swc_context_relocation(struct svga_winsys_context *swc,
			   uint32 *cid)
{
   *cid = swc->cid;
}

static bool
vmw_swc_add_validate_buffer(struct vmw_svga_winsys_context *vswc,
			    struct pb_buffer *pb_buf,
			    unsigned flags)
{
   ASSERTED enum pipe_error ret;
   unsigned translated_flags;
   bool already_present;

   translated_flags = vmw_translate_to_pb_flags(flags);
   ret = pb_validate_add_buffer(vswc->validate, pb_buf, translated_flags,
                                vswc->hash, &already_present);
   assert(ret == PIPE_OK);
   return !already_present;
}

static void
vmw_swc_region_relocation(struct svga_winsys_context *swc,
                          struct SVGAGuestPtr *where,
                          struct svga_winsys_buffer *buffer,
                          uint32 offset,
                          unsigned flags)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_buffer_relocation *reloc;

   assert(vswc->region.staged < vswc->region.reserved);

   reloc = &vswc->region.relocs[vswc->region.used + vswc->region.staged];
   reloc->region.where = where;

   /*
    * pb_validate holds a refcount to the buffer, so no need to
    * refcount it again in the relocation.
    */
   reloc->buffer = vmw_pb_buffer(buffer);
   reloc->offset = offset;
   reloc->is_mob = false;
   ++vswc->region.staged;

   if (vmw_swc_add_validate_buffer(vswc, reloc->buffer, flags)) {
      vswc->seen_regions += reloc->buffer->base.size;
      if ((swc->hints & SVGA_HINT_FLAG_CAN_PRE_FLUSH) &&
          vswc->seen_regions >= VMW_GMR_POOL_SIZE/5)
         vswc->preemptive_flush = true;
   }

#if MESA_DEBUG
   if (!(flags & SVGA_RELOC_INTERNAL))
      debug_flush_cb_reference(vswc->fctx, vmw_debug_flush_buf(buffer));
#endif
}

static void
vmw_swc_mob_relocation(struct svga_winsys_context *swc,
		       SVGAMobId *id,
		       uint32 *offset_into_mob,
		       struct svga_winsys_buffer *buffer,
		       uint32 offset,
		       unsigned flags)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_buffer_relocation *reloc;
   struct pb_buffer *pb_buffer = vmw_pb_buffer(buffer);

   if (id) {
      assert(vswc->region.staged < vswc->region.reserved);

      reloc = &vswc->region.relocs[vswc->region.used + vswc->region.staged];
      reloc->mob.id = id;
      reloc->mob.offset_into_mob = offset_into_mob;

      /*
       * pb_validate holds a refcount to the buffer, so no need to
       * refcount it again in the relocation.
       */
      reloc->buffer = pb_buffer;
      reloc->offset = offset;
      reloc->is_mob = true;
      ++vswc->region.staged;
   }

   if (vmw_swc_add_validate_buffer(vswc, pb_buffer, flags)) {
      vswc->seen_mobs += pb_buffer->base.size;

      if ((swc->hints & SVGA_HINT_FLAG_CAN_PRE_FLUSH) &&
          vswc->seen_mobs >=
            vswc->vws->ioctl.max_mob_memory / VMW_MAX_MOB_MEM_FACTOR)
         vswc->preemptive_flush = true;
   }

#if MESA_DEBUG
   if (!(flags & SVGA_RELOC_INTERNAL))
      debug_flush_cb_reference(vswc->fctx, vmw_debug_flush_buf(buffer));
#endif
}


/**
 * vmw_swc_surface_clear_reference - Clear referenced info for a surface
 *
 * @swc:   Pointer to an svga_winsys_context
 * @vsurf: Pointer to a vmw_svga_winsys_surface, the referenced info of which
 *         we want to clear
 *
 * This is primarily used by a discard surface map to indicate that the
 * surface data is no longer referenced by a draw call, and mapping it
 * should therefore no longer cause a flush.
 */
void
vmw_swc_surface_clear_reference(struct svga_winsys_context *swc,
                                struct vmw_svga_winsys_surface *vsurf)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_ctx_validate_item *isrf =
      util_hash_table_get(vswc->hash, vsurf);

   if (isrf && isrf->referenced) {
      isrf->referenced = false;
      p_atomic_dec(&vsurf->validated);
   }
}

static void
vmw_swc_surface_only_relocation(struct svga_winsys_context *swc,
				uint32 *where,
				struct vmw_svga_winsys_surface *vsurf,
				unsigned flags)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_ctx_validate_item *isrf;

   assert(vswc->surface.staged < vswc->surface.reserved);
   isrf = util_hash_table_get(vswc->hash, vsurf);

   if (isrf == NULL) {
      isrf = &vswc->surface.items[vswc->surface.used + vswc->surface.staged];
      vmw_svga_winsys_surface_reference(&isrf->vsurf, vsurf);
      isrf->referenced = false;

      _mesa_hash_table_insert(vswc->hash, vsurf, isrf);
      ++vswc->surface.staged;

      vswc->seen_surfaces += vsurf->size;
      if ((swc->hints & SVGA_HINT_FLAG_CAN_PRE_FLUSH) &&
          vswc->seen_surfaces >=
            vswc->vws->ioctl.max_surface_memory / VMW_MAX_SURF_MEM_FACTOR)
         vswc->preemptive_flush = true;
   }

   if (!(flags & SVGA_RELOC_INTERNAL) && !isrf->referenced) {
      isrf->referenced = true;
      p_atomic_inc(&vsurf->validated);
   }

   if (where)
      *where = vsurf->sid;
}

static void
vmw_swc_surface_relocation(struct svga_winsys_context *swc,
                           uint32 *where,
                           uint32 *mobid,
                           struct svga_winsys_surface *surface,
                           unsigned flags)
{
   struct vmw_svga_winsys_surface *vsurf;

   assert(swc->have_gb_objects || mobid == NULL);

   if (!surface) {
      *where = SVGA3D_INVALID_ID;
      if (mobid)
         *mobid = SVGA3D_INVALID_ID;
      return;
   }

   vsurf = vmw_svga_winsys_surface(surface);
   vmw_swc_surface_only_relocation(swc, where, vsurf, flags);

   if (swc->have_gb_objects && vsurf->buf != NULL) {

      /*
       * Make sure backup buffer ends up fenced.
       */

      mtx_lock(&vsurf->mutex);
      assert(vsurf->buf != NULL);

      /*
       * An internal reloc means that the surface transfer direction
       * is opposite to the MOB transfer direction...
       */
      if ((flags & SVGA_RELOC_INTERNAL) &&
          (flags & (SVGA_RELOC_READ | SVGA_RELOC_WRITE)) !=
          (SVGA_RELOC_READ | SVGA_RELOC_WRITE))
         flags ^= (SVGA_RELOC_READ | SVGA_RELOC_WRITE);
      vmw_swc_mob_relocation(swc, mobid, NULL, (struct svga_winsys_buffer *)
                             vsurf->buf, 0, flags);
      mtx_unlock(&vsurf->mutex);
   }
}

static void
vmw_swc_shader_relocation(struct svga_winsys_context *swc,
			  uint32 *shid,
			  uint32 *mobid,
			  uint32 *offset,
			  struct svga_winsys_gb_shader *shader,
                          unsigned flags)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_winsys_screen *vws = vswc->vws;
   struct vmw_svga_winsys_shader *vshader;
   struct vmw_ctx_validate_item *ishader;

   if(!shader) {
      *shid = SVGA3D_INVALID_ID;
      return;
   }

   vshader = vmw_svga_winsys_shader(shader);

   if (!vws->base.have_vgpu10) {
      assert(vswc->shader.staged < vswc->shader.reserved);
      ishader = util_hash_table_get(vswc->hash, vshader);

      if (ishader == NULL) {
         ishader = &vswc->shader.items[vswc->shader.used + vswc->shader.staged];
         vmw_svga_winsys_shader_reference(&ishader->vshader, vshader);
         ishader->referenced = false;

         _mesa_hash_table_insert(vswc->hash, vshader, ishader);
         ++vswc->shader.staged;
      }

      if (!ishader->referenced) {
         ishader->referenced = true;
         p_atomic_inc(&vshader->validated);
      }
   }

   if (shid)
      *shid = vshader->shid;

   if (vshader->buf)
      vmw_swc_mob_relocation(swc, mobid, offset, vshader->buf,
			     0, SVGA_RELOC_READ);
}

static void
vmw_swc_query_relocation(struct svga_winsys_context *swc,
                         SVGAMobId *id,
                         struct svga_winsys_gb_query *query)
{
   /* Queries are backed by one big MOB */
   vmw_swc_mob_relocation(swc, id, NULL, query->buf, 0,
                          SVGA_RELOC_READ | SVGA_RELOC_WRITE);
}

static void
vmw_swc_commit(struct svga_winsys_context *swc)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);

   assert(vswc->command.used + vswc->command.reserved <= vswc->command.size);
   vswc->command.used += vswc->command.reserved;
   vswc->command.reserved = 0;

   assert(vswc->surface.staged <= vswc->surface.reserved);
   assert(vswc->surface.used + vswc->surface.staged <= vswc->surface.size);
   vswc->surface.used += vswc->surface.staged;
   vswc->surface.staged = 0;
   vswc->surface.reserved = 0;

   assert(vswc->shader.staged <= vswc->shader.reserved);
   assert(vswc->shader.used + vswc->shader.staged <= vswc->shader.size);
   vswc->shader.used += vswc->shader.staged;
   vswc->shader.staged = 0;
   vswc->shader.reserved = 0;

   assert(vswc->region.staged <= vswc->region.reserved);
   assert(vswc->region.used + vswc->region.staged <= vswc->region.size);
   vswc->region.used += vswc->region.staged;
   vswc->region.staged = 0;
   vswc->region.reserved = 0;
}


static void
vmw_swc_destroy(struct svga_winsys_context *swc)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   unsigned i;

   for(i = 0; i < vswc->surface.used; ++i) {
      struct vmw_ctx_validate_item *isurf = &vswc->surface.items[i];
      if (isurf->referenced)
         p_atomic_dec(&isurf->vsurf->validated);
      vmw_svga_winsys_surface_reference(&isurf->vsurf, NULL);
   }

   for(i = 0; i < vswc->shader.used; ++i) {
      struct vmw_ctx_validate_item *ishader = &vswc->shader.items[i];
      if (ishader->referenced)
         p_atomic_dec(&ishader->vshader->validated);
      vmw_svga_winsys_shader_reference(&ishader->vshader, NULL);
   }

   if (vmw_has_userspace_surface(vswc->vws))
      util_bitmask_destroy(vswc->surface_id_bm);
   _mesa_hash_table_destroy(vswc->hash, NULL);
   pb_validate_destroy(vswc->validate);
   vmw_ioctl_context_destroy(vswc->vws, swc->cid);
   if (vswc->vws->swc == swc)
      vswc->vws->swc = NULL;
#if MESA_DEBUG
   debug_flush_ctx_destroy(vswc->fctx);
#endif
   FREE(vswc);
}

void
vmw_swc_unref(struct svga_winsys_context *swc)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   if (p_atomic_dec_zero(&vswc->refcount)) {
      vmw_swc_destroy(swc);
   }
}

/**
 * vmw_svga_winsys_vgpu10_shader_screate - The winsys shader_crate callback
 *
 * @swc: The winsys context.
 * @shaderId: Previously allocated shader id.
 * @shaderType: The shader type.
 * @bytecode: The shader bytecode
 * @bytecodelen: The length of the bytecode.
 *
 * Creates an svga_winsys_gb_shader structure and allocates a buffer for the
 * shader code and copies the shader code into the buffer. Shader
 * resource creation is not done.
 */
static struct svga_winsys_gb_shader *
vmw_svga_winsys_vgpu10_shader_create(struct svga_winsys_context *swc,
                                     uint32 shaderId,
                                     SVGA3dShaderType shaderType,
                                     const uint32 *bytecode,
                                     uint32 bytecodeLen,
                                     const SVGA3dDXShaderSignatureHeader *sgnInfo,
                                     uint32 sgnLen)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   struct vmw_svga_winsys_shader *shader;
   shader = vmw_svga_shader_create(&vswc->vws->base, shaderType, bytecode,
                                   bytecodeLen, sgnInfo, sgnLen);
   if (!shader)
      return NULL;

   shader->shid = shaderId;
   return svga_winsys_shader(shader);
}

/**
 * vmw_svga_winsys_vgpu10_shader_destroy - The winsys shader_destroy callback.
 *
 * @swc: The winsys context.
 * @shader: A shader structure previously allocated by shader_create.
 *
 * Frees the shader structure and the buffer holding the shader code.
 */
static void
vmw_svga_winsys_vgpu10_shader_destroy(struct svga_winsys_context *swc,
                                      struct svga_winsys_gb_shader *shader)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);

   vmw_svga_winsys_shader_destroy(&vswc->vws->base, shader);
}

/**
 * vmw_svga_winsys_resource_rebind - The winsys resource_rebind callback
 *
 * @swc: The winsys context.
 * @surface: The surface to be referenced.
 * @shader: The shader to be referenced.
 * @flags: Relocation flags.
 *
 * This callback is needed because shader backing buffers are sub-allocated, and
 * hence the kernel fencing is not sufficient. The buffers need to be put on
 * the context's validation list and fenced after command submission to avoid
 * reuse of busy shader buffers. In addition, surfaces need to be put on the
 * validation list in order for the driver to regard them as referenced
 * by the command stream.
 */
static enum pipe_error
vmw_svga_winsys_resource_rebind(struct svga_winsys_context *swc,
                                struct svga_winsys_surface *surface,
                                struct svga_winsys_gb_shader *shader,
                                unsigned flags)
{
   /**
    * Need to reserve one validation item for either the surface or
    * the shader.
    */
   if (!vmw_swc_reserve(swc, 0, 1))
      return PIPE_ERROR_OUT_OF_MEMORY;

   if (surface)
      vmw_swc_surface_relocation(swc, NULL, NULL, surface, flags);
   else if (shader)
      vmw_swc_shader_relocation(swc, NULL, NULL, NULL, shader, flags);

   vmw_swc_commit(swc);

   return PIPE_OK;
}

struct svga_winsys_context *
vmw_svga_winsys_context_create(struct svga_winsys_screen *sws)
{
   struct vmw_winsys_screen *vws = vmw_winsys_screen(sws);
   struct vmw_svga_winsys_context *vswc;

   vswc = CALLOC_STRUCT(vmw_svga_winsys_context);
   if(!vswc)
      return NULL;

   vswc->base.destroy = vmw_swc_unref;
   vswc->base.reserve = vmw_swc_reserve;
   vswc->base.get_command_buffer_size = vmw_swc_get_command_buffer_size;
   vswc->base.surface_relocation = vmw_swc_surface_relocation;
   vswc->base.region_relocation = vmw_swc_region_relocation;
   vswc->base.mob_relocation = vmw_swc_mob_relocation;
   vswc->base.query_relocation = vmw_swc_query_relocation;
   vswc->base.query_bind = vmw_swc_query_bind;
   vswc->base.context_relocation = vmw_swc_context_relocation;
   vswc->base.shader_relocation = vmw_swc_shader_relocation;
   vswc->base.commit = vmw_swc_commit;
   vswc->base.flush = vmw_swc_flush;
   vswc->base.surface_map = vmw_svga_winsys_surface_map;
   vswc->base.surface_unmap = vmw_svga_winsys_surface_unmap;

   vswc->base.shader_create = vmw_svga_winsys_vgpu10_shader_create;
   vswc->base.shader_destroy = vmw_svga_winsys_vgpu10_shader_destroy;

   vswc->base.resource_rebind = vmw_svga_winsys_resource_rebind;

   if (sws->have_vgpu10)
      vswc->base.cid = vmw_ioctl_extended_context_create(vws, sws->have_vgpu10);
   else
      vswc->base.cid = vmw_ioctl_context_create(vws);

   if (vswc->base.cid == -1)
      goto out_no_context;

   vswc->base.imported_fence_fd = -1;

   vswc->base.have_gb_objects = sws->have_gb_objects;

   vswc->vws = vws;

   vswc->command.size = VMW_COMMAND_SIZE;
   vswc->surface.size = VMW_SURFACE_RELOCS;
   vswc->shader.size = VMW_SHADER_RELOCS;
   vswc->region.size = VMW_REGION_RELOCS;

   vswc->validate = pb_validate_create();
   if(!vswc->validate)
      goto out_no_validate;

   vswc->hash = util_hash_table_create_ptr_keys();
   if (!vswc->hash)
      goto out_no_hash;

   if (vmw_has_userspace_surface(vws)) {
      if(!(vswc->surface_id_bm = util_bitmask_create()))
         goto out_no_user_srf;
      /**
       * First id assigned is 0 which is invalid for surface id. Consume the
       * first id.
       */
      vmw_swc_surface_add_userspace_id(&vswc->base);
   }

   /**
    * The context refcount is initialized to 2, one reference is for the context
    * itself and the other is for vws screen. One unref is done when context
    * destroy is called and the other when the either vws screen is destroyed
    * or it initializes another context.
    * This ensures that a screen always has access to its last created context.
    * The vws screen needs this context to submit surface commands for userspace
    * managed surfaces.
    */
   p_atomic_set(&vswc->refcount, 1);
   if (vws->swc)
      vmw_swc_unref(vws->swc);
   vws->swc = &vswc->base;
   p_atomic_inc(&vswc->refcount);

#if MESA_DEBUG
   vswc->fctx = debug_flush_ctx_create(true, VMW_DEBUG_FLUSH_STACK);
#endif

   vswc->base.force_coherent = vws->force_coherent;
   return &vswc->base;

out_no_user_srf:
   _mesa_hash_table_destroy(vswc->hash, NULL);
out_no_hash:
   pb_validate_destroy(vswc->validate);
out_no_validate:
   vmw_ioctl_context_destroy(vws, vswc->base.cid);
out_no_context:
   FREE(vswc);
   return NULL;
}

void
vmw_swc_surface_clear_userspace_id(struct svga_winsys_context *swc,
                                   uint32 sid)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   util_bitmask_clear(vswc->surface_id_bm, sid);
}

uint32_t
vmw_swc_surface_add_userspace_id(struct svga_winsys_context *swc)
{
   struct vmw_svga_winsys_context *vswc = vmw_svga_winsys_context(swc);
   return util_bitmask_add(vswc->surface_id_bm);
}