drm/vmwgfx: Fix handling of dumb buffers

Dumb buffers can be used in kms but also through prime with gallium's
resource_from_handle. In the second case the dumb buffers can be
rendered by the GPU where with the regular DRM kms interfaces they
are mapped and written to by the CPU. Because the same buffer can
be written to by the GPU and CPU vmwgfx needs to use vmw_surface (object
which properly tracks dirty state of the guest and gpu memory)
instead of vmw_bo (which is just guest side memory).

Furthermore the dumb buffer handles are expected to be gem objects by
a lot of userspace.

Make vmwgfx accept gem handles in prime and kms but internally switch
to vmw_surface's to properly track the dirty state of the objects between
the GPU and CPU.

Fixes new kwin and kde on wayland.

Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Fixes: b32233acceff ("drm/vmwgfx: Fix prime import/export")
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.9+
Reviewed-by: Maaz Mombasawala <maaz.mombasawala@broadcom.com>
Reviewed-by: Martin Krastev <martin.krastev@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240722184313.181318-4-zack.rusin@broadcom.com

1 files changed, 76 insertions, 51 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index 00144632c600..f42ebc4a7c22 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0 OR MIT
 /**************************************************************************
  *
- * Copyright © 2011-2023 VMware, Inc., Palo Alto, CA., USA
- * All Rights Reserved.
+ * Copyright (c) 2011-2024 Broadcom. All Rights Reserved. The term
+ * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
@@ -28,15 +28,39 @@
 
 #include "vmwgfx_bo.h"
 #include "vmwgfx_drv.h"
-
+#include "vmwgfx_resource_priv.h"
 
 #include <drm/ttm/ttm_placement.h>
 
 static void vmw_bo_release(struct vmw_bo *vbo)
 {
+	struct vmw_resource *res;
+
 	WARN_ON(vbo->tbo.base.funcs &&
 		kref_read(&vbo->tbo.base.refcount) != 0);
 	vmw_bo_unmap(vbo);
+
+	xa_destroy(&vbo->detached_resources);
+	WARN_ON(vbo->is_dumb && !vbo->dumb_surface);
+	if (vbo->is_dumb && vbo->dumb_surface) {
+		res = &vbo->dumb_surface->res;
+		WARN_ON(vbo != res->guest_memory_bo);
+		WARN_ON(!res->guest_memory_bo);
+		if (res->guest_memory_bo) {
+			/* Reserve and switch the backing mob. */
+			mutex_lock(&res->dev_priv->cmdbuf_mutex);
+			(void)vmw_resource_reserve(res, false, true);
+			vmw_resource_mob_detach(res);
+			if (res->coherent)
+				vmw_bo_dirty_release(res->guest_memory_bo);
+			res->guest_memory_bo = NULL;
+			res->guest_memory_offset = 0;
+			vmw_resource_unreserve(res, false, false, false, NULL,
+					       0);
+			mutex_unlock(&res->dev_priv->cmdbuf_mutex);
+		}
+		vmw_surface_unreference(&vbo->dumb_surface);
+	}
 	drm_gem_object_release(&vbo->tbo.base);
 }
 
@@ -326,6 +350,11 @@ void vmw_bo_pin_reserved(struct vmw_bo *vbo, bool pin)
  */
 void *vmw_bo_map_and_cache(struct vmw_bo *vbo)
 {
+	return vmw_bo_map_and_cache_size(vbo, vbo->tbo.base.size);
+}
+
+void *vmw_bo_map_and_cache_size(struct vmw_bo *vbo, size_t size)
+{
 	struct ttm_buffer_object *bo = &vbo->tbo;
 	bool not_used;
 	void *virtual;
@@ -335,9 +364,10 @@ void *vmw_bo_map_and_cache(struct vmw_bo *vbo)
 	if (virtual)
 		return virtual;
 
-	ret = ttm_bo_kmap(bo, 0, PFN_UP(bo->base.size), &vbo->map);
+	ret = ttm_bo_kmap(bo, 0, PFN_UP(size), &vbo->map);
 	if (ret)
-		DRM_ERROR("Buffer object map failed: %d.\n", ret);
+		DRM_ERROR("Buffer object map failed: %d (size: bo = %zu, map = %zu).\n",
+			  ret, bo->base.size, size);
 
 	return ttm_kmap_obj_virtual(&vbo->map, &not_used);
 }
@@ -390,6 +420,7 @@ static int vmw_bo_init(struct vmw_private *dev_priv,
 	BUILD_BUG_ON(TTM_MAX_BO_PRIORITY <= 3);
 	vmw_bo->tbo.priority = 3;
 	vmw_bo->res_tree = RB_ROOT;
+	xa_init(&vmw_bo->detached_resources);
 
 	params->size = ALIGN(params->size, PAGE_SIZE);
 	drm_gem_private_object_init(vdev, &vmw_bo->tbo.base, params->size);
@@ -654,52 +685,6 @@ void vmw_bo_fence_single(struct ttm_buffer_object *bo,
 	dma_fence_put(&fence->base);
 }
 
-
-/**
- * vmw_dumb_create - Create a dumb kms buffer
- *
- * @file_priv: Pointer to a struct drm_file identifying the caller.
- * @dev: Pointer to the drm device.
- * @args: Pointer to a struct drm_mode_create_dumb structure
- * Return: Zero on success, negative error code on failure.
- *
- * This is a driver callback for the core drm create_dumb functionality.
- * Note that this is very similar to the vmw_bo_alloc ioctl, except
- * that the arguments have a different format.
- */
-int vmw_dumb_create(struct drm_file *file_priv,
-		    struct drm_device *dev,
-		    struct drm_mode_create_dumb *args)
-{
-	struct vmw_private *dev_priv = vmw_priv(dev);
-	struct vmw_bo *vbo;
-	int cpp = DIV_ROUND_UP(args->bpp, 8);
-	int ret;
-
-	switch (cpp) {
-	case 1: /* DRM_FORMAT_C8 */
-	case 2: /* DRM_FORMAT_RGB565 */
-	case 4: /* DRM_FORMAT_XRGB8888 */
-		break;
-	default:
-		/*
-		 * Dumb buffers don't allow anything else.
-		 * This is tested via IGT's dumb_buffers
-		 */
-		return -EINVAL;
-	}
-
-	args->pitch = args->width * cpp;
-	args->size = ALIGN(args->pitch * args->height, PAGE_SIZE);
-
-	ret = vmw_gem_object_create_with_handle(dev_priv, file_priv,
-						args->size, &args->handle,
-						&vbo);
-	/* drop reference from allocate - handle holds it now */
-	drm_gem_object_put(&vbo->tbo.base);
-	return ret;
-}
-
 /**
  * vmw_bo_swap_notify - swapout notify callback.
  *
@@ -853,3 +838,43 @@ void vmw_bo_placement_set_default_accelerated(struct vmw_bo *bo)
 
 	vmw_bo_placement_set(bo, domain, domain);
 }
+
+void vmw_bo_add_detached_resource(struct vmw_bo *vbo, struct vmw_resource *res)
+{
+	xa_store(&vbo->detached_resources, (unsigned long)res, res, GFP_KERNEL);
+}
+
+void vmw_bo_del_detached_resource(struct vmw_bo *vbo, struct vmw_resource *res)
+{
+	xa_erase(&vbo->detached_resources, (unsigned long)res);
+}
+
+struct vmw_surface *vmw_bo_surface(struct vmw_bo *vbo)
+{
+	unsigned long index;
+	struct vmw_resource *res = NULL;
+	struct vmw_surface *surf = NULL;
+	struct rb_node *rb_itr = vbo->res_tree.rb_node;
+
+	if (vbo->is_dumb && vbo->dumb_surface) {
+		res = &vbo->dumb_surface->res;
+		goto out;
+	}
+
+	xa_for_each(&vbo->detached_resources, index, res) {
+		if (res->func->res_type == vmw_res_surface)
+			goto out;
+	}
+
+	for (rb_itr = rb_first(&vbo->res_tree); rb_itr;
+	     rb_itr = rb_next(rb_itr)) {
+		res = rb_entry(rb_itr, struct vmw_resource, mob_node);
+		if (res->func->res_type == vmw_res_surface)
+			goto out;
+	}
+
+out:
+	if (res)
+		surf = vmw_res_to_srf(res);
+	return surf;
+}