xref: /linux/drivers/gpu/drm/i915/display/intel_fbdev_fb.c (revision 74ba587f402d5501af2c85e50cf1e4044263b6ca)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include <drm/drm_fb_helper.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_display_core.h"
14 #include "intel_display_types.h"
15 #include "intel_fb.h"
16 #include "intel_fbdev_fb.h"
17 
18 struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_fb_helper *helper,
19 					       struct drm_fb_helper_surface_size *sizes)
20 {
21 	struct intel_display *display = to_intel_display(helper->dev);
22 	struct drm_i915_private *dev_priv = to_i915(display->drm);
23 	struct drm_framebuffer *fb;
24 	struct drm_mode_fb_cmd2 mode_cmd = {};
25 	struct drm_i915_gem_object *obj;
26 	int size;
27 
28 	/* we don't do packed 24bpp */
29 	if (sizes->surface_bpp == 24)
30 		sizes->surface_bpp = 32;
31 
32 	mode_cmd.width = sizes->surface_width;
33 	mode_cmd.height = sizes->surface_height;
34 
35 	mode_cmd.pitches[0] = ALIGN(mode_cmd.width *
36 				    DIV_ROUND_UP(sizes->surface_bpp, 8), 64);
37 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
38 							  sizes->surface_depth);
39 
40 	size = mode_cmd.pitches[0] * mode_cmd.height;
41 	size = PAGE_ALIGN(size);
42 
43 	obj = ERR_PTR(-ENODEV);
44 	if (HAS_LMEM(dev_priv)) {
45 		obj = i915_gem_object_create_lmem(dev_priv, size,
46 						  I915_BO_ALLOC_CONTIGUOUS |
47 						  I915_BO_ALLOC_USER);
48 	} else {
49 		/*
50 		 * If the FB is too big, just don't use it since fbdev is not very
51 		 * important and we should probably use that space with FBC or other
52 		 * features.
53 		 *
54 		 * Also skip stolen on MTL as Wa_22018444074 mitigation.
55 		 */
56 		if (!display->platform.meteorlake && size * 2 < dev_priv->dsm.usable_size)
57 			obj = i915_gem_object_create_stolen(dev_priv, size);
58 		if (IS_ERR(obj))
59 			obj = i915_gem_object_create_shmem(dev_priv, size);
60 	}
61 
62 	if (IS_ERR(obj)) {
63 		drm_err(display->drm, "failed to allocate framebuffer (%pe)\n", obj);
64 		return ERR_PTR(-ENOMEM);
65 	}
66 
67 	fb = intel_framebuffer_create(intel_bo_to_drm_bo(obj),
68 				      drm_get_format_info(display->drm,
69 							  mode_cmd.pixel_format,
70 							  mode_cmd.modifier[0]),
71 				      &mode_cmd);
72 	i915_gem_object_put(obj);
73 
74 	return to_intel_framebuffer(fb);
75 }
76 
77 int intel_fbdev_fb_fill_info(struct intel_display *display, struct fb_info *info,
78 			     struct drm_gem_object *_obj, struct i915_vma *vma)
79 {
80 	struct drm_i915_private *i915 = to_i915(display->drm);
81 	struct drm_i915_gem_object *obj = to_intel_bo(_obj);
82 	struct i915_gem_ww_ctx ww;
83 	void __iomem *vaddr;
84 	int ret;
85 
86 	if (i915_gem_object_is_lmem(obj)) {
87 		struct intel_memory_region *mem = obj->mm.region;
88 
89 		/* Use fbdev's framebuffer from lmem for discrete */
90 		info->fix.smem_start =
91 			(unsigned long)(mem->io.start +
92 					i915_gem_object_get_dma_address(obj, 0) -
93 					mem->region.start);
94 		info->fix.smem_len = obj->base.size;
95 	} else {
96 		struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
97 
98 		/* Our framebuffer is the entirety of fbdev's system memory */
99 		info->fix.smem_start =
100 			(unsigned long)(ggtt->gmadr.start + i915_ggtt_offset(vma));
101 		info->fix.smem_len = vma->size;
102 	}
103 
104 	for_i915_gem_ww(&ww, ret, false) {
105 		ret = i915_gem_object_lock(vma->obj, &ww);
106 
107 		if (ret)
108 			continue;
109 
110 		vaddr = i915_vma_pin_iomap(vma);
111 		if (IS_ERR(vaddr)) {
112 			drm_err(display->drm,
113 				"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
114 			ret = PTR_ERR(vaddr);
115 			continue;
116 		}
117 	}
118 
119 	if (ret)
120 		return ret;
121 
122 	info->screen_base = vaddr;
123 	info->screen_size = intel_bo_to_drm_bo(obj)->size;
124 
125 	return 0;
126 }
127