/*
 * 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 "pipe/p_defines.h"
#include "vmw_surface.h"
#include "vmw_screen.h"
#include "vmw_buffer.h"
#include "vmw_context.h"
#include "pipebuffer/pb_bufmgr.h"

void
vmw_svga_winsys_surface_init(struct svga_winsys_screen *sws,
                             struct svga_winsys_surface *srf,
                             unsigned surf_size, SVGA3dSurfaceAllFlags flags)
{
   struct vmw_svga_winsys_surface *vsrf = vmw_svga_winsys_surface(srf);
   void *data = NULL;
   struct pb_buffer *pb_buf;
   uint32_t pb_flags;
   struct vmw_winsys_screen *vws = vsrf->screen;
   pb_flags = PIPE_MAP_WRITE | PIPE_MAP_DISCARD_WHOLE_RESOURCE;

   struct pb_manager *provider;
   struct pb_desc desc;

   mtx_lock(&vsrf->mutex);
   data = vmw_svga_winsys_buffer_map(&vws->base, vsrf->buf, pb_flags);
   if (data)
      goto out_mapped;

   provider = vws->pools.dma_fenced;
   memset(&desc, 0, sizeof(desc));
   desc.alignment = 4096;
   pb_buf = provider->create_buffer(provider, vsrf->size, &desc);
   if (pb_buf != NULL) {
      struct svga_winsys_buffer *vbuf =
         vmw_svga_winsys_buffer_wrap(pb_buf);

      data = vmw_svga_winsys_buffer_map(&vws->base, vbuf, pb_flags);
      if (data) {
         vsrf->rebind = true;
         if (vsrf->buf)
            vmw_svga_winsys_buffer_destroy(&vws->base, vsrf->buf);
         vsrf->buf = vbuf;
         goto out_mapped;
      } else {
         vmw_svga_winsys_buffer_destroy(&vws->base, vbuf);
         goto out_unlock;
      }
   }
   else {
      /* Cannot create a buffer, just unlock */
      goto out_unlock;
   }

out_mapped:
   mtx_unlock(&vsrf->mutex);

   if (data) {
      if (flags & SVGA3D_SURFACE_BIND_STREAM_OUTPUT) {
         memset(data, 0, surf_size + sizeof(SVGA3dDXSOState));
      }
      else {
         memset(data, 0, surf_size);
      }
   }

   mtx_lock(&vsrf->mutex);
   vmw_svga_winsys_buffer_unmap(&vsrf->screen->base, vsrf->buf);
out_unlock:
   mtx_unlock(&vsrf->mutex);
}

 
void *
vmw_svga_winsys_surface_map(struct svga_winsys_context *swc,
                            struct svga_winsys_surface *srf,
                            unsigned flags, bool *retry,
                            bool *rebind)
{
   struct vmw_svga_winsys_surface *vsrf = vmw_svga_winsys_surface(srf);
   void *data = NULL;
   struct pb_buffer *pb_buf;
   uint32_t pb_flags;
   struct vmw_winsys_screen *vws = vsrf->screen;

   *retry = false;
   *rebind = false;
   assert((flags & (PIPE_MAP_READ | PIPE_MAP_WRITE)) != 0);
   mtx_lock(&vsrf->mutex);

   if (vsrf->mapcount) {
      /* Other mappers will get confused if we discard. */
      flags &= ~PIPE_MAP_DISCARD_WHOLE_RESOURCE;
   }

   vsrf->rebind = false;

   /*
    * If we intend to read, there's no point discarding the
    * data if busy.
    */
   if (flags & PIPE_MAP_READ || vsrf->nodiscard)
      flags &= ~PIPE_MAP_DISCARD_WHOLE_RESOURCE;

   /*
    * Discard is a hint to a synchronized map.
    */
   if (flags & PIPE_MAP_DISCARD_WHOLE_RESOURCE)
      flags &= ~PIPE_MAP_UNSYNCHRONIZED;

   /*
    * The surface is allowed to be referenced on the command stream iff
    * we're mapping unsynchronized or discard. This is an early check.
    * We need to recheck after a failing discard map.
    */
   if (!(flags & (PIPE_MAP_DISCARD_WHOLE_RESOURCE |
                  PIPE_MAP_UNSYNCHRONIZED)) &&
       p_atomic_read(&vsrf->validated)) {
      *retry = true;
      goto out_unlock;
   }

   pb_flags = flags & (PIPE_MAP_READ_WRITE | PIPE_MAP_UNSYNCHRONIZED |
      PIPE_MAP_PERSISTENT);

   if (flags & PIPE_MAP_DISCARD_WHOLE_RESOURCE) {
      struct pb_manager *provider;
      struct pb_desc desc;

      /*
       * First, if possible, try to map existing storage with DONTBLOCK.
       */
      if (!p_atomic_read(&vsrf->validated)) {
         data = vmw_svga_winsys_buffer_map(&vws->base, vsrf->buf,
                                           PIPE_MAP_DONTBLOCK | pb_flags);
         if (data)
            goto out_mapped;
      } 

      /*
       * Attempt to get a new buffer.
       */
      provider = vws->pools.dma_fenced;
      memset(&desc, 0, sizeof(desc));
      desc.alignment = 4096;
      pb_buf = provider->create_buffer(provider, vsrf->size, &desc);
      if (pb_buf != NULL) {
         struct svga_winsys_buffer *vbuf =
            vmw_svga_winsys_buffer_wrap(pb_buf);

         data = vmw_svga_winsys_buffer_map(&vws->base, vbuf, pb_flags);
         if (data) {
            vsrf->rebind = true;
            /*
             * We've discarded data on this surface and thus
             * it's data is no longer consider referenced.
             */
            vmw_swc_surface_clear_reference(swc, vsrf);
            if (vsrf->buf)
               vmw_svga_winsys_buffer_destroy(&vws->base, vsrf->buf);
            vsrf->buf = vbuf;

            /* Rebind persistent maps immediately */
            if (flags & PIPE_MAP_PERSISTENT) {
               *rebind = true;
               vsrf->rebind = false;
            }
            goto out_mapped;
         } else
            vmw_svga_winsys_buffer_destroy(&vws->base, vbuf);
      }
      /*
       * We couldn't get and map a new buffer for some reason.
       * Fall through to an ordinary map.
       * But tell pipe driver to flush now if already on validate list,
       * Otherwise we'll overwrite previous contents.
       */
      if (!(flags & PIPE_MAP_UNSYNCHRONIZED) && 
          p_atomic_read(&vsrf->validated)) {
         *retry = true;
         goto out_unlock;
      }
   }

   pb_flags |= (flags & PIPE_MAP_DONTBLOCK);
   data = vmw_svga_winsys_buffer_map(&vws->base, vsrf->buf, pb_flags);
   if (data == NULL)
      goto out_unlock;

out_mapped:
   ++vsrf->mapcount;
   vsrf->data = data;
   vsrf->map_mode = flags & (PIPE_MAP_READ | PIPE_MAP_WRITE);
out_unlock:
   mtx_unlock(&vsrf->mutex);
   return data;
}


void
vmw_svga_winsys_surface_unmap(struct svga_winsys_context *swc,
                              struct svga_winsys_surface *srf,
                              bool *rebind)
{
   struct vmw_svga_winsys_surface *vsrf = vmw_svga_winsys_surface(srf);
   mtx_lock(&vsrf->mutex);
   if (--vsrf->mapcount == 0) {
      *rebind = vsrf->rebind;
      vsrf->rebind = false;
   } else {
      *rebind = false;
   }
   vmw_svga_winsys_buffer_unmap(&vsrf->screen->base, vsrf->buf);
   mtx_unlock(&vsrf->mutex);
}

void
vmw_svga_winsys_surface_reference(struct vmw_svga_winsys_surface **pdst,
                                  struct vmw_svga_winsys_surface *src)
{
   struct pipe_reference *src_ref;
   struct pipe_reference *dst_ref;
   struct vmw_svga_winsys_surface *dst;

   if(pdst == NULL || *pdst == src)
      return;

   dst = *pdst;

   src_ref = src ? &src->refcnt : NULL;
   dst_ref = dst ? &dst->refcnt : NULL;

   if (pipe_reference(dst_ref, src_ref)) {
      if (dst->buf)
         vmw_svga_winsys_buffer_destroy(&dst->screen->base, dst->buf);
      vmw_ioctl_surface_destroy(dst->screen, dst->sid);
#if MESA_DEBUG
      /* to detect dangling pointers */
      assert(p_atomic_read(&dst->validated) == 0);
      dst->sid = SVGA3D_INVALID_ID;
#endif
      mtx_destroy(&dst->mutex);
      FREE(dst);
   }

   *pdst = src;
}