1// SPDX-License-Identifier: MIT
2/* Copyright © 2025 Intel Corporation */
3
4#include <drm/drm_cache.h>
5#include <drm/drm_panic.h>
6
7#include "intel_display_types.h"
8#include "intel_fb.h"
9#include "intel_panic.h"
10#include "xe_bo.h"
11#include "xe_res_cursor.h"
12
13struct intel_panic {
14 struct xe_res_cursor res;
15 struct iosys_map vmap;
16
17 int page;
18};
19
20static void xe_panic_kunmap(struct intel_panic *panic)
21{
22 if (!panic->vmap.is_iomem && iosys_map_is_set(map: &panic->vmap)) {
23 drm_clflush_virt_range(addr: panic->vmap.vaddr, PAGE_SIZE);
24 kunmap_local(panic->vmap.vaddr);
25 }
26 iosys_map_clear(map: &panic->vmap);
27 panic->page = -1;
28}
29
30/*
31 * The scanout buffer pages are not mapped, so for each pixel,
32 * use kmap_local_page_try_from_panic() to map the page, and write the pixel.
33 * Try to keep the map from the previous pixel, to avoid too much map/unmap.
34 */
35static void xe_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
36 unsigned int y, u32 color)
37{
38 struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
39 struct intel_panic *panic = fb->panic;
40 struct xe_bo *bo = gem_to_xe_bo(obj: intel_fb_bo(&fb->base));
41 unsigned int new_page;
42 unsigned int offset;
43
44 if (fb->panic_tiling)
45 offset = fb->panic_tiling(sb->width, x, y);
46 else
47 offset = y * sb->pitch[0] + x * sb->format->cpp[0];
48
49 new_page = offset >> PAGE_SHIFT;
50 offset = offset % PAGE_SIZE;
51 if (new_page != panic->page) {
52 if (xe_bo_is_vram(bo)) {
53 /* Display is always mapped on root tile */
54 struct xe_vram_region *vram = xe_bo_device(bo)->mem.vram;
55
56 if (panic->page < 0 || new_page < panic->page) {
57 xe_res_first(res: bo->ttm.resource, start: new_page * PAGE_SIZE,
58 size: bo->ttm.base.size - new_page * PAGE_SIZE, cur: &panic->res);
59 } else {
60 xe_res_next(cur: &panic->res, PAGE_SIZE * (new_page - panic->page));
61 }
62 iosys_map_set_vaddr_iomem(map: &panic->vmap,
63 vaddr_iomem: vram->mapping + panic->res.start);
64 } else {
65 xe_panic_kunmap(panic);
66 iosys_map_set_vaddr(map: &panic->vmap,
67 vaddr: ttm_bo_kmap_try_from_panic(bo: &bo->ttm,
68 page: new_page));
69 }
70 panic->page = new_page;
71 }
72
73 if (iosys_map_is_set(map: &panic->vmap))
74 iosys_map_wr(&panic->vmap, offset, u32, color);
75}
76
77struct intel_panic *intel_panic_alloc(void)
78{
79 struct intel_panic *panic;
80
81 panic = kzalloc(sizeof(*panic), GFP_KERNEL);
82
83 return panic;
84}
85
86int intel_panic_setup(struct intel_panic *panic, struct drm_scanout_buffer *sb)
87{
88 struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
89 struct xe_bo *bo = gem_to_xe_bo(obj: intel_fb_bo(&fb->base));
90
91 if (xe_bo_is_vram(bo) && !xe_bo_is_visible_vram(bo))
92 return -ENODEV;
93
94 panic->page = -1;
95 sb->set_pixel = xe_panic_page_set_pixel;
96 return 0;
97}
98
99void intel_panic_finish(struct intel_panic *panic)
100{
101 xe_panic_kunmap(panic);
102}
103

source code of linux/drivers/gpu/drm/xe/display/xe_panic.c