xref: /linux/drivers/gpu/drm/i915/display/intel_fbdev_fb.c (revision 13c072b8e91a5ccb5855ca1ba6fe3ea467dbf94d)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include <linux/fb.h>
7 
8 #include <drm/drm_print.h>
9 
10 #include "gem/i915_gem_lmem.h"
11 
12 #include "i915_drv.h"
13 #include "intel_fbdev_fb.h"
14 
15 u32 intel_fbdev_fb_pitch_align(u32 stride)
16 {
17 	return ALIGN(stride, 64);
18 }
19 
20 bool intel_fbdev_fb_prefer_stolen(struct drm_device *drm, unsigned int size)
21 {
22 	struct drm_i915_private *i915 = to_i915(drm);
23 
24 	/* Skip stolen on MTL as Wa_22018444074 mitigation. */
25 	if (IS_METEORLAKE(i915))
26 		return false;
27 
28 	/*
29 	 * If the FB is too big, just don't use it since fbdev is not very
30 	 * important and we should probably use that space with FBC or other
31 	 * features.
32 	 */
33 	return i915->dsm.usable_size >= size * 2;
34 }
35 
36 struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size)
37 {
38 	struct drm_i915_private *i915 = to_i915(drm);
39 	struct drm_i915_gem_object *obj;
40 
41 	obj = ERR_PTR(-ENODEV);
42 	if (HAS_LMEM(i915)) {
43 		obj = i915_gem_object_create_lmem(i915, size,
44 						  I915_BO_ALLOC_CONTIGUOUS |
45 						  I915_BO_ALLOC_USER);
46 	} else {
47 		if (intel_fbdev_fb_prefer_stolen(drm, size))
48 			obj = i915_gem_object_create_stolen(i915, size);
49 		else
50 			drm_info(drm, "Allocating fbdev: Stolen memory not preferred.\n");
51 
52 		if (IS_ERR(obj))
53 			obj = i915_gem_object_create_shmem(i915, size);
54 	}
55 
56 	if (IS_ERR(obj)) {
57 		drm_err(drm, "failed to allocate framebuffer (%pe)\n", obj);
58 		return ERR_PTR(-ENOMEM);
59 	}
60 
61 	return &obj->base;
62 }
63 
64 void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj)
65 {
66 	drm_gem_object_put(obj);
67 }
68 
69 int intel_fbdev_fb_fill_info(struct drm_device *drm, struct fb_info *info,
70 			     struct drm_gem_object *_obj, struct i915_vma *vma)
71 {
72 	struct drm_i915_private *i915 = to_i915(drm);
73 	struct drm_i915_gem_object *obj = to_intel_bo(_obj);
74 	struct i915_gem_ww_ctx ww;
75 	void __iomem *vaddr;
76 	int ret;
77 
78 	if (i915_gem_object_is_lmem(obj)) {
79 		struct intel_memory_region *mem = obj->mm.region;
80 
81 		/* Use fbdev's framebuffer from lmem for discrete */
82 		info->fix.smem_start =
83 			(unsigned long)(mem->io.start +
84 					i915_gem_object_get_dma_address(obj, 0) -
85 					mem->region.start);
86 		info->fix.smem_len = obj->base.size;
87 	} else {
88 		struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
89 
90 		/* Our framebuffer is the entirety of fbdev's system memory */
91 		info->fix.smem_start =
92 			(unsigned long)(ggtt->gmadr.start + i915_ggtt_offset(vma));
93 		info->fix.smem_len = vma->size;
94 	}
95 
96 	for_i915_gem_ww(&ww, ret, false) {
97 		ret = i915_gem_object_lock(vma->obj, &ww);
98 
99 		if (ret)
100 			continue;
101 
102 		vaddr = i915_vma_pin_iomap(vma);
103 		if (IS_ERR(vaddr)) {
104 			drm_err(drm,
105 				"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
106 			ret = PTR_ERR(vaddr);
107 			continue;
108 		}
109 	}
110 
111 	if (ret)
112 		return ret;
113 
114 	info->screen_base = vaddr;
115 	info->screen_size = intel_bo_to_drm_bo(obj)->size;
116 
117 	return 0;
118 }
119