xref: /linux/drivers/gpu/drm/xe/display/xe_panic.c (revision 68a052239fc4b351e961f698b824f7654a346091)
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 
12 struct intel_panic {
13 	struct page **pages;
14 	int page;
15 	void *vaddr;
16 };
17 
18 static void xe_panic_kunmap(struct intel_panic *panic)
19 {
20 	if (panic->vaddr) {
21 		drm_clflush_virt_range(panic->vaddr, PAGE_SIZE);
22 		kunmap_local(panic->vaddr);
23 		panic->vaddr = NULL;
24 	}
25 }
26 
27 /*
28  * The scanout buffer pages are not mapped, so for each pixel,
29  * use kmap_local_page_try_from_panic() to map the page, and write the pixel.
30  * Try to keep the map from the previous pixel, to avoid too much map/unmap.
31  */
32 static void xe_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
33 				    unsigned int y, u32 color)
34 {
35 	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
36 	struct intel_panic *panic = fb->panic;
37 	struct xe_bo *bo = gem_to_xe_bo(intel_fb_bo(&fb->base));
38 	unsigned int new_page;
39 	unsigned int offset;
40 
41 	if (fb->panic_tiling)
42 		offset = fb->panic_tiling(sb->width, x, y);
43 	else
44 		offset = y * sb->pitch[0] + x * sb->format->cpp[0];
45 
46 	new_page = offset >> PAGE_SHIFT;
47 	offset = offset % PAGE_SIZE;
48 	if (new_page != panic->page) {
49 		xe_panic_kunmap(panic);
50 		panic->page = new_page;
51 		panic->vaddr = ttm_bo_kmap_try_from_panic(&bo->ttm,
52 							  panic->page);
53 	}
54 	if (panic->vaddr) {
55 		u32 *pix = panic->vaddr + offset;
56 		*pix = color;
57 	}
58 }
59 
60 struct intel_panic *intel_panic_alloc(void)
61 {
62 	struct intel_panic *panic;
63 
64 	panic = kzalloc(sizeof(*panic), GFP_KERNEL);
65 
66 	return panic;
67 }
68 
69 int intel_panic_setup(struct intel_panic *panic, struct drm_scanout_buffer *sb)
70 {
71 	panic->page = -1;
72 	sb->set_pixel = xe_panic_page_set_pixel;
73 	return 0;
74 }
75 
76 void intel_panic_finish(struct intel_panic *panic)
77 {
78 	xe_panic_kunmap(panic);
79 	panic->page = -1;
80 }
81