xref: /linux/drivers/gpu/drm/i915/display/intel_fbdev_fb.c (revision a1d0a0549d425cb21e2be4b7fd4f76e0379e6f2d)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include <linux/fb.h>
7 
8 #include "gem/i915_gem_lmem.h"
9 
10 #include "i915_drv.h"
11 #include "intel_fbdev_fb.h"
12 
13 struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size)
14 {
15 	struct drm_i915_private *dev_priv = to_i915(drm);
16 	struct drm_i915_gem_object *obj;
17 
18 	obj = ERR_PTR(-ENODEV);
19 	if (HAS_LMEM(dev_priv)) {
20 		obj = i915_gem_object_create_lmem(dev_priv, size,
21 						  I915_BO_ALLOC_CONTIGUOUS |
22 						  I915_BO_ALLOC_USER);
23 	} else {
24 		/*
25 		 * If the FB is too big, just don't use it since fbdev is not very
26 		 * important and we should probably use that space with FBC or other
27 		 * features.
28 		 *
29 		 * Also skip stolen on MTL as Wa_22018444074 mitigation.
30 		 */
31 		if (!IS_METEORLAKE(dev_priv) && size * 2 < dev_priv->dsm.usable_size)
32 			obj = i915_gem_object_create_stolen(dev_priv, size);
33 		if (IS_ERR(obj))
34 			obj = i915_gem_object_create_shmem(dev_priv, size);
35 	}
36 
37 	if (IS_ERR(obj)) {
38 		drm_err(drm, "failed to allocate framebuffer (%pe)\n", obj);
39 		return ERR_PTR(-ENOMEM);
40 	}
41 
42 	return &obj->base;
43 }
44 
45 void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj)
46 {
47 	drm_gem_object_put(obj);
48 }
49 
50 int intel_fbdev_fb_fill_info(struct drm_device *drm, struct fb_info *info,
51 			     struct drm_gem_object *_obj, struct i915_vma *vma)
52 {
53 	struct drm_i915_private *i915 = to_i915(drm);
54 	struct drm_i915_gem_object *obj = to_intel_bo(_obj);
55 	struct i915_gem_ww_ctx ww;
56 	void __iomem *vaddr;
57 	int ret;
58 
59 	if (i915_gem_object_is_lmem(obj)) {
60 		struct intel_memory_region *mem = obj->mm.region;
61 
62 		/* Use fbdev's framebuffer from lmem for discrete */
63 		info->fix.smem_start =
64 			(unsigned long)(mem->io.start +
65 					i915_gem_object_get_dma_address(obj, 0) -
66 					mem->region.start);
67 		info->fix.smem_len = obj->base.size;
68 	} else {
69 		struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
70 
71 		/* Our framebuffer is the entirety of fbdev's system memory */
72 		info->fix.smem_start =
73 			(unsigned long)(ggtt->gmadr.start + i915_ggtt_offset(vma));
74 		info->fix.smem_len = vma->size;
75 	}
76 
77 	for_i915_gem_ww(&ww, ret, false) {
78 		ret = i915_gem_object_lock(vma->obj, &ww);
79 
80 		if (ret)
81 			continue;
82 
83 		vaddr = i915_vma_pin_iomap(vma);
84 		if (IS_ERR(vaddr)) {
85 			drm_err(drm,
86 				"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
87 			ret = PTR_ERR(vaddr);
88 			continue;
89 		}
90 	}
91 
92 	if (ret)
93 		return ret;
94 
95 	info->screen_base = vaddr;
96 	info->screen_size = intel_bo_to_drm_bo(obj)->size;
97 
98 	return 0;
99 }
100