drivers/gpu/drm/panfrost/panfrost_dump.c

   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
  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
  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
 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                         *bomap++ = page_to_phys(sg_page_iter_page(&page_iter));
 225
 226                 iter.hdr->bomap.iova = mapping->mmnode.start << PAGE_SHIFT;
 227
 228                 vaddr = map.vaddr;
 229                 memcpy(iter.data, vaddr, bo->base.base.size);
 230
 231                 drm_gem_vunmap_unlocked(&bo->base.base, &map);
 232
 233                 iter.hdr->bomap.valid = 1;
 234
 235 dump_header:    panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_BO, iter.data +
 236                                           bo->base.base.size);
 237         }
 238         panfrost_core_dump_header(&iter, PANFROSTDUMP_BUF_TRAILER, iter.data);
 239
 240         dev_coredumpv(pfdev->dev, iter.start, iter.data - iter.start, GFP_KERNEL);
 241 }