linux/drivers/gpu/drm/etnaviv/etnaviv_dump.c
Lucas Stach ca8cb69580 drm/etnaviv: fix deadlock in GPU coredump
The GPU coredump function violates the locking order by holding the MMU
context lock while trying to acquire the etnaviv_gem_object lock. This
results in a possible ABBA deadlock with other codepaths which follow
the established locking order.
Fortunately this is easy to fix by dropping the MMU context lock
earlier, as the BO dumping doesn't need the MMU context to be stable.
The only thing the BO dumping cares about are the BO mappings, which
are stable across the lifetime of the job.

Fixes: 27b67278e0 (drm/etnaviv: rework MMU handling)
[ Not really the first bad commit, but the one where this fix applies
  cleanly. Stable kernels need a manual backport. ]
Reported-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
2019-10-29 18:11:06 +01:00

230 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015-2018 Etnaviv Project
*/
#include <linux/devcoredump.h>
#include <linux/moduleparam.h>
#include "etnaviv_cmdbuf.h"
#include "etnaviv_dump.h"
#include "etnaviv_gem.h"
#include "etnaviv_gpu.h"
#include "etnaviv_mmu.h"
#include "etnaviv_sched.h"
#include "state.xml.h"
#include "state_hi.xml.h"
static bool etnaviv_dump_core = true;
module_param_named(dump_core, etnaviv_dump_core, bool, 0600);
struct core_dump_iterator {
void *start;
struct etnaviv_dump_object_header *hdr;
void *data;
};
static const unsigned short etnaviv_dump_registers[] = {
VIVS_HI_AXI_STATUS,
VIVS_HI_CLOCK_CONTROL,
VIVS_HI_IDLE_STATE,
VIVS_HI_AXI_CONFIG,
VIVS_HI_INTR_ENBL,
VIVS_HI_CHIP_IDENTITY,
VIVS_HI_CHIP_FEATURE,
VIVS_HI_CHIP_MODEL,
VIVS_HI_CHIP_REV,
VIVS_HI_CHIP_DATE,
VIVS_HI_CHIP_TIME,
VIVS_HI_CHIP_MINOR_FEATURE_0,
VIVS_HI_CACHE_CONTROL,
VIVS_HI_AXI_CONTROL,
VIVS_PM_POWER_CONTROLS,
VIVS_PM_MODULE_CONTROLS,
VIVS_PM_MODULE_STATUS,
VIVS_PM_PULSE_EATER,
VIVS_MC_MMU_FE_PAGE_TABLE,
VIVS_MC_MMU_TX_PAGE_TABLE,
VIVS_MC_MMU_PE_PAGE_TABLE,
VIVS_MC_MMU_PEZ_PAGE_TABLE,
VIVS_MC_MMU_RA_PAGE_TABLE,
VIVS_MC_DEBUG_MEMORY,
VIVS_MC_MEMORY_BASE_ADDR_RA,
VIVS_MC_MEMORY_BASE_ADDR_FE,
VIVS_MC_MEMORY_BASE_ADDR_TX,
VIVS_MC_MEMORY_BASE_ADDR_PEZ,
VIVS_MC_MEMORY_BASE_ADDR_PE,
VIVS_MC_MEMORY_TIMING_CONTROL,
VIVS_MC_BUS_CONFIG,
VIVS_FE_DMA_STATUS,
VIVS_FE_DMA_DEBUG_STATE,
VIVS_FE_DMA_ADDRESS,
VIVS_FE_DMA_LOW,
VIVS_FE_DMA_HIGH,
VIVS_FE_AUTO_FLUSH,
};
static void etnaviv_core_dump_header(struct core_dump_iterator *iter,
u32 type, void *data_end)
{
struct etnaviv_dump_object_header *hdr = iter->hdr;
hdr->magic = cpu_to_le32(ETDUMP_MAGIC);
hdr->type = cpu_to_le32(type);
hdr->file_offset = cpu_to_le32(iter->data - iter->start);
hdr->file_size = cpu_to_le32(data_end - iter->data);
iter->hdr++;
iter->data += hdr->file_size;
}
static void etnaviv_core_dump_registers(struct core_dump_iterator *iter,
struct etnaviv_gpu *gpu)
{
struct etnaviv_dump_registers *reg = iter->data;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(etnaviv_dump_registers); i++, reg++) {
reg->reg = etnaviv_dump_registers[i];
reg->value = gpu_read(gpu, etnaviv_dump_registers[i]);
}
etnaviv_core_dump_header(iter, ETDUMP_BUF_REG, reg);
}
static void etnaviv_core_dump_mmu(struct core_dump_iterator *iter,
struct etnaviv_iommu_context *mmu, size_t mmu_size)
{
etnaviv_iommu_dump(mmu, iter->data);
etnaviv_core_dump_header(iter, ETDUMP_BUF_MMU, iter->data + mmu_size);
}
static void etnaviv_core_dump_mem(struct core_dump_iterator *iter, u32 type,
void *ptr, size_t size, u64 iova)
{
memcpy(iter->data, ptr, size);
iter->hdr->iova = cpu_to_le64(iova);
etnaviv_core_dump_header(iter, type, iter->data + size);
}
void etnaviv_core_dump(struct etnaviv_gem_submit *submit)
{
struct etnaviv_gpu *gpu = submit->gpu;
struct core_dump_iterator iter;
struct etnaviv_gem_object *obj;
unsigned int n_obj, n_bomap_pages;
size_t file_size, mmu_size;
__le64 *bomap, *bomap_start;
int i;
/* Only catch the first event, or when manually re-armed */
if (!etnaviv_dump_core)
return;
etnaviv_dump_core = false;
mutex_lock(&gpu->mmu_context->lock);
mmu_size = etnaviv_iommu_dump_size(gpu->mmu_context);
/* We always dump registers, mmu, ring, hanging cmdbuf and end marker */
n_obj = 5;
n_bomap_pages = 0;
file_size = ARRAY_SIZE(etnaviv_dump_registers) *
sizeof(struct etnaviv_dump_registers) +
mmu_size + gpu->buffer.size + submit->cmdbuf.size;
/* Add in the active buffer objects */
for (i = 0; i < submit->nr_bos; i++) {
obj = submit->bos[i].obj;
file_size += obj->base.size;
n_bomap_pages += obj->base.size >> PAGE_SHIFT;
n_obj++;
}
/* If we have any buffer objects, add a bomap object */
if (n_bomap_pages) {
file_size += n_bomap_pages * sizeof(__le64);
n_obj++;
}
/* Add the size of the headers */
file_size += sizeof(*iter.hdr) * n_obj;
/* Allocate the file in vmalloc memory, it's likely to be big */
iter.start = __vmalloc(file_size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
PAGE_KERNEL);
if (!iter.start) {
mutex_unlock(&gpu->mmu_context->lock);
dev_warn(gpu->dev, "failed to allocate devcoredump file\n");
return;
}
/* Point the data member after the headers */
iter.hdr = iter.start;
iter.data = &iter.hdr[n_obj];
memset(iter.hdr, 0, iter.data - iter.start);
etnaviv_core_dump_registers(&iter, gpu);
etnaviv_core_dump_mmu(&iter, gpu->mmu_context, mmu_size);
etnaviv_core_dump_mem(&iter, ETDUMP_BUF_RING, gpu->buffer.vaddr,
gpu->buffer.size,
etnaviv_cmdbuf_get_va(&gpu->buffer,
&gpu->mmu_context->cmdbuf_mapping));
etnaviv_core_dump_mem(&iter, ETDUMP_BUF_CMD,
submit->cmdbuf.vaddr, submit->cmdbuf.size,
etnaviv_cmdbuf_get_va(&submit->cmdbuf,
&gpu->mmu_context->cmdbuf_mapping));
mutex_unlock(&gpu->mmu_context->lock);
/* Reserve space for the bomap */
if (n_bomap_pages) {
bomap_start = bomap = iter.data;
memset(bomap, 0, sizeof(*bomap) * n_bomap_pages);
etnaviv_core_dump_header(&iter, ETDUMP_BUF_BOMAP,
bomap + n_bomap_pages);
} else {
/* Silence warning */
bomap_start = bomap = NULL;
}
for (i = 0; i < submit->nr_bos; i++) {
struct etnaviv_vram_mapping *vram;
struct page **pages;
void *vaddr;
obj = submit->bos[i].obj;
vram = submit->bos[i].mapping;
mutex_lock(&obj->lock);
pages = etnaviv_gem_get_pages(obj);
mutex_unlock(&obj->lock);
if (!IS_ERR(pages)) {
int j;
iter.hdr->data[0] = bomap - bomap_start;
for (j = 0; j < obj->base.size >> PAGE_SHIFT; j++)
*bomap++ = cpu_to_le64(page_to_phys(*pages++));
}
iter.hdr->iova = cpu_to_le64(vram->iova);
vaddr = etnaviv_gem_vmap(&obj->base);
if (vaddr)
memcpy(iter.data, vaddr, obj->base.size);
etnaviv_core_dump_header(&iter, ETDUMP_BUF_BO, iter.data +
obj->base.size);
}
etnaviv_core_dump_header(&iter, ETDUMP_BUF_END, iter.data);
dev_coredumpv(gpu->dev, iter.start, iter.data - iter.start, GFP_KERNEL);
}