1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2021 Collabora ltd. */
3 
4 #include <linux/err.h>
5 #include <linux/device.h>
6 #include <linux/devcoredump.h>
7 #include <linux/moduleparam.h>
8 #include <linux/iosys-map.h>
9 #include <drm/panfrost_drm.h>
10 #include <drm/drm_device.h>
11 
12 #include "panfrost_job.h"
13 #include "panfrost_gem.h"
14 #include "panfrost_regs.h"
15 #include "panfrost_dump.h"
16 #include "panfrost_device.h"
17 
18 static bool panfrost_dump_core = true;
19 module_param_named(dump_core, panfrost_dump_core, bool, 0600);
20 
21 struct panfrost_dump_iterator {
22 	void *start;
23 	struct panfrost_dump_object_header *hdr;
24 	void *data;
25 };
26 
27 static const unsigned short panfrost_dump_registers[] = {
28 	SHADER_READY_LO,
29 	SHADER_READY_HI,
30 	TILER_READY_LO,
31 	TILER_READY_HI,
32 	L2_READY_LO,
33 	L2_READY_HI,
34 	JOB_INT_MASK,
35 	JOB_INT_STAT,
36 	JS_HEAD_LO(0),
37 	JS_HEAD_HI(0),
38 	JS_TAIL_LO(0),
39 	JS_TAIL_HI(0),
40 	JS_AFFINITY_LO(0),
41 	JS_AFFINITY_HI(0),
42 	JS_CONFIG(0),
43 	JS_STATUS(0),
44 	JS_HEAD_NEXT_LO(0),
45 	JS_HEAD_NEXT_HI(0),
46 	JS_AFFINITY_NEXT_LO(0),
47 	JS_AFFINITY_NEXT_HI(0),
48 	JS_CONFIG_NEXT(0),
49 	MMU_INT_MASK,
50 	MMU_INT_STAT,
51 	AS_TRANSTAB_LO(0),
52 	AS_TRANSTAB_HI(0),
53 	AS_MEMATTR_LO(0),
54 	AS_MEMATTR_HI(0),
55 	AS_FAULTSTATUS(0),
56 	AS_FAULTADDRESS_LO(0),
57 	AS_FAULTADDRESS_HI(0),
58 	AS_STATUS(0),
59 };
60 
panfrost_core_dump_header(struct panfrost_dump_iterator * iter,u32 type,void * data_end)61 static void panfrost_core_dump_header(struct panfrost_dump_iterator *iter,
62 				      u32 type, void *data_end)
63 {
64 	struct panfrost_dump_object_header *hdr = iter->hdr;
65 
66 	hdr->magic = PANFROSTDUMP_MAGIC;
67 	hdr->type = type;
68 	hdr->file_offset = iter->data - iter->start;
69 	hdr->file_size = data_end - iter->data;
70 
71 	iter->hdr++;
72 	iter->data += hdr->file_size;
73 }
74 
75 static void
panfrost_core_dump_registers(struct panfrost_dump_iterator * iter,struct panfrost_device * pfdev,u32 as_nr,int slot)76 panfrost_core_dump_registers(struct panfrost_dump_iterator *iter,
77 			     struct panfrost_device *pfdev,
78 			     u32 as_nr, int slot)
79 {
80 	struct panfrost_dump_registers *dumpreg = iter->data;
81 	unsigned int i;
82 
83 	for (i = 0; i < ARRAY_SIZE(panfrost_dump_registers); i++, dumpreg++) {
84 		unsigned int js_as_offset = 0;
85 		unsigned int reg;
86 
87 		if (panfrost_dump_registers[i] >= JS_BASE &&
88 		    panfrost_dump_registers[i] <= JS_BASE + JS_SLOT_STRIDE)
89 			js_as_offset = slot * JS_SLOT_STRIDE;
90 		else if (panfrost_dump_registers[i] >= MMU_BASE &&
91 			 panfrost_dump_registers[i] <= MMU_BASE + MMU_AS_STRIDE)
92 			js_as_offset = (as_nr << MMU_AS_SHIFT);
93 
94 		reg = panfrost_dump_registers[i] + js_as_offset;
95 
96 		dumpreg->reg = reg;
97 		dumpreg->value = gpu_read(pfdev, reg);
98 	}
99 
100 	panfrost_core_dump_header(iter, PANFROSTDUMP_BUF_REG, dumpreg);
101 }
102 
panfrost_core_dump(struct panfrost_job * job)103 void panfrost_core_dump(struct panfrost_job *job)
104 {
105 	struct panfrost_device *pfdev = job->pfdev;
106 	struct panfrost_dump_iterator iter;
107 	struct drm_gem_object *dbo;
108 	unsigned int n_obj, n_bomap_pages;
109 	u64 *bomap, *bomap_start;
110 	size_t file_size;
111 	u32 as_nr;
112 	int slot;
113 	int ret, i;
114 
115 	as_nr = job->mmu->as;
116 	slot = panfrost_job_get_slot(job);
117 
118 	/* Only catch the first event, or when manually re-armed */
119 	if (!panfrost_dump_core)
120 		return;
121 	panfrost_dump_core = false;
122 
123 	/* At least, we dump registers and end marker */
124 	n_obj = 2;
125 	n_bomap_pages = 0;
126 	file_size = ARRAY_SIZE(panfrost_dump_registers) *
127 			sizeof(struct panfrost_dump_registers);
128 
129 	/* Add in the active buffer objects */
130 	for (i = 0; i < job->bo_count; i++) {
131 		/*
132 		 * Even though the CPU could be configured to use 16K or 64K pages, this
133 		 * is a very unusual situation for most kernel setups on SoCs that have
134 		 * a Panfrost device. Also many places across the driver make the somewhat
135 		 * arbitrary assumption that Panfrost's MMU page size is the same as the CPU's,
136 		 * so let's have a sanity check to ensure that's always the case
137 		 */
138 		dbo = job->bos[i];
139 		WARN_ON(!IS_ALIGNED(dbo->size, PAGE_SIZE));
140 
141 		file_size += dbo->size;
142 		n_bomap_pages += dbo->size >> PAGE_SHIFT;
143 		n_obj++;
144 	}
145 
146 	/* If we have any buffer objects, add a bomap object */
147 	if (n_bomap_pages) {
148 		file_size += n_bomap_pages * sizeof(*bomap);
149 		n_obj++;
150 	}
151 
152 	/* Add the size of the headers */
153 	file_size += sizeof(*iter.hdr) * n_obj;
154 
155 	/*
156 	 * Allocate the file in vmalloc memory, it's likely to be big.
157 	 * The reason behind these GFP flags is that we don't want to trigger the
158 	 * OOM killer in the event that not enough memory could be found for our
159 	 * dump file. We also don't want the allocator to do any error reporting,
160 	 * as the right behaviour is failing gracefully if a big enough buffer
161 	 * could not be allocated.
162 	 */
163 	iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN |
164 			__GFP_NORETRY);
165 	if (!iter.start) {
166 		dev_warn(pfdev->dev, "failed to allocate devcoredump file\n");
167 		return;
168 	}
169 
170 	/* Point the data member after the headers */
171 	iter.hdr = iter.start;
172 	iter.data = &iter.hdr[n_obj];
173 
174 	memset(iter.hdr, 0, iter.data - iter.start);
175 
176 	/*
177 	 * For now, we write the job identifier in the register dump header,
178 	 * so that we can decode the entire dump later with pandecode
179 	 */
180 	iter.hdr->reghdr.jc = job->jc;
181 	iter.hdr->reghdr.major = PANFROSTDUMP_MAJOR;
182 	iter.hdr->reghdr.minor = PANFROSTDUMP_MINOR;
183 	iter.hdr->reghdr.gpu_id = pfdev->features.id;
184 	iter.hdr->reghdr.nbos = job->bo_count;
185 
186 	panfrost_core_dump_registers(&iter, pfdev, as_nr, slot);
187 
188 	/* Reserve space for the bomap */
189 	if (job->bo_count) {
190 		bomap_start = bomap = iter.data;
191 		memset(bomap, 0, sizeof(*bomap) * n_bomap_pages);
192 		panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_BOMAP,
193 					  bomap + n_bomap_pages);
194 	}
195 
196 	for (i = 0; i < job->bo_count; i++) {
197 		struct iosys_map map;
198 		struct panfrost_gem_mapping *mapping;
199 		struct panfrost_gem_object *bo;
200 		struct sg_page_iter page_iter;
201 		void *vaddr;
202 
203 		bo = to_panfrost_bo(job->bos[i]);
204 		mapping = job->mappings[i];
205 
206 		if (!bo->base.sgt) {
207 			dev_err(pfdev->dev, "Panfrost Dump: BO has no sgt, cannot dump\n");
208 			iter.hdr->bomap.valid = 0;
209 			goto dump_header;
210 		}
211 
212 		ret = drm_gem_vmap_unlocked(&bo->base.base, &map);
213 		if (ret) {
214 			dev_err(pfdev->dev, "Panfrost Dump: couldn't map Buffer Object\n");
215 			iter.hdr->bomap.valid = 0;
216 			goto dump_header;
217 		}
218 
219 		WARN_ON(!mapping->active);
220 
221 		iter.hdr->bomap.data[0] = bomap - bomap_start;
222 
223 		for_each_sgtable_page(bo->base.sgt, &page_iter, 0) {
224 			struct page *page = sg_page_iter_page(&page_iter);
225 
226 			if (!IS_ERR(page)) {
227 				*bomap++ = page_to_phys(page);
228 			} else {
229 				dev_err(pfdev->dev, "Panfrost Dump: wrong page\n");
230 				*bomap++ = 0;
231 			}
232 		}
233 
234 		iter.hdr->bomap.iova = mapping->mmnode.start << PAGE_SHIFT;
235 
236 		vaddr = map.vaddr;
237 		memcpy(iter.data, vaddr, bo->base.base.size);
238 
239 		drm_gem_vunmap_unlocked(&bo->base.base, &map);
240 
241 		iter.hdr->bomap.valid = 1;
242 
243 dump_header:	panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_BO, iter.data +
244 					  bo->base.base.size);
245 	}
246 	panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_TRAILER, iter.data);
247 
248 	dev_coredumpv(pfdev->dev, iter.start, iter.data - iter.start, GFP_KERNEL);
249 }
250