zink: avoid the descriptor set multiplier for bindless buffers

the bindless descriptor buffer is already correctly sized, so it needs
to avoid the huge set multiplier or it'll explode all available vram

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21216>

src/gallium/drivers/zink/zink_descriptors.c

@@ -1489,7 +1489,7 @@ zink_descriptors_init_bindless(struct zink_context *ctx)
       unsigned bind = ZINK_BIND_RESOURCE_DESCRIPTOR | ZINK_BIND_SAMPLER_DESCRIPTOR;
       VkDeviceSize size;
       VKSCR(GetDescriptorSetLayoutSizeEXT)(screen->dev, screen->bindless_layout, &size);
-      struct pipe_resource *pres = pipe_buffer_create(&screen->base, bind, 0, size);
+      struct pipe_resource *pres = pipe_buffer_create(&screen->base, bind, ZINK_USAGE_BINDLESS, size);
       ctx->dd.db.bindless_db = zink_resource(pres);
       ctx->dd.db.bindless_db_map = pipe_buffer_map(&ctx->base, pres, PIPE_MAP_READ | PIPE_MAP_WRITE, &ctx->dd.db.bindless_db_xfer);
       zink_batch_bind_db(ctx);

src/gallium/drivers/zink/zink_resource.c

@@ -180,7 +180,8 @@ create_bci(struct zink_screen *screen, const struct pipe_resource *templ, unsign
 
    if (bind & ZINK_BIND_DESCRIPTOR) {
       /* gallium sizes are all uint32_t, while the total size of this buffer may exceed that limit */
-      bci.size *= ZINK_DESCRIPTOR_BUFFER_MULTIPLIER;
+      if (templ->usage != ZINK_USAGE_BINDLESS)
+         bci.size *= ZINK_DESCRIPTOR_BUFFER_MULTIPLIER;
       bci.usage = 0;
       if (bind & ZINK_BIND_SAMPLER_DESCRIPTOR)
          bci.usage |= VK_BUFFER_USAGE_SAMPLER_DESCRIPTOR_BUFFER_BIT_EXT;

src/gallium/drivers/zink/zink_resource.h

@@ -27,6 +27,7 @@
 #include "zink_types.h"
 
 #define ZINK_MAP_TEMPORARY (PIPE_MAP_DRV_PRV << 0)
+#define ZINK_USAGE_BINDLESS 128 //this is used for bindless descriptors
 #define ZINK_BIND_SAMPLER_DESCRIPTOR (1u << 26)
 #define ZINK_BIND_RESOURCE_DESCRIPTOR (1u << 27)
 #define ZINK_BIND_DESCRIPTOR (ZINK_BIND_SAMPLER_DESCRIPTOR | ZINK_BIND_RESOURCE_DESCRIPTOR)