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alistair23-linux/drivers/gpu/drm/i915/intel_guc_log.h

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/*
* Copyright © 2014-2017 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#ifndef _INTEL_GUC_LOG_H_
#define _INTEL_GUC_LOG_H_
#include <linux/mutex.h>
#include <linux/relay.h>
#include <linux/workqueue.h>
#include "intel_guc_fwif.h"
#include "i915_gem.h"
struct intel_guc;
#ifdef CONFIG_DRM_I915_DEBUG_GUC
#define CRASH_BUFFER_SIZE SZ_2M
#define DPC_BUFFER_SIZE SZ_8M
#define ISR_BUFFER_SIZE SZ_8M
#else
#define CRASH_BUFFER_SIZE SZ_8K
#define DPC_BUFFER_SIZE SZ_32K
#define ISR_BUFFER_SIZE SZ_32K
#endif
drm/i915/guc: Fix lockdep due to log relay channel handling under struct_mutex This patch fixes lockdep issue due to circular locking dependency of struct_mutex, i_mutex_key, mmap_sem, relay_channels_mutex. For GuC log relay channel we create debugfs file that requires i_mutex_key lock and we are doing that under struct_mutex. So we introduced newer dependency as: &dev->struct_mutex --> &sb->s_type->i_mutex_key#3 --> &mm->mmap_sem However, there is dependency from mmap_sem to struct_mutex. Hence we separate the relay create/destroy operation from under struct_mutex. Also added runtime check of relay buffer status. Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> ====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc6-CI-Patchwork_7614+ #1 Not tainted ------------------------------------------------------ debugfs_test/1388 is trying to acquire lock: (&dev->struct_mutex){+.+.}, at: [<00000000d5e1d915>] i915_mutex_lock_interruptible+0x47/0x130 [i915] but task is already holding lock: (&mm->mmap_sem){++++}, at: [<0000000029a9c131>] __do_page_fault+0x106/0x560 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++}: _copy_to_user+0x1e/0x70 filldir+0x8c/0xf0 dcache_readdir+0xeb/0x160 iterate_dir+0xdc/0x140 SyS_getdents+0xa0/0x130 entry_SYSCALL_64_fastpath+0x1c/0x89 -> #2 (&sb->s_type->i_mutex_key#3){++++}: start_creating+0x59/0x110 __debugfs_create_file+0x2e/0xe0 relay_create_buf_file+0x62/0x80 relay_late_setup_files+0x84/0x250 guc_log_late_setup+0x4f/0x110 [i915] i915_guc_log_register+0x32/0x40 [i915] i915_driver_load+0x7b6/0x1720 [i915] i915_pci_probe+0x2e/0x90 [i915] pci_device_probe+0x9c/0x120 driver_probe_device+0x2a3/0x480 __driver_attach+0xd9/0xe0 bus_for_each_dev+0x57/0x90 bus_add_driver+0x168/0x260 driver_register+0x52/0xc0 do_one_initcall+0x39/0x150 do_init_module+0x56/0x1ef load_module+0x231c/0x2d70 SyS_finit_module+0xa5/0xe0 entry_SYSCALL_64_fastpath+0x1c/0x89 -> #1 (relay_channels_mutex){+.+.}: relay_open+0x12c/0x2b0 intel_guc_log_runtime_create+0xab/0x230 [i915] intel_guc_init+0x81/0x120 [i915] intel_uc_init+0x29/0xa0 [i915] i915_gem_init+0x182/0x530 [i915] i915_driver_load+0xaa9/0x1720 [i915] i915_pci_probe+0x2e/0x90 [i915] pci_device_probe+0x9c/0x120 driver_probe_device+0x2a3/0x480 __driver_attach+0xd9/0xe0 bus_for_each_dev+0x57/0x90 bus_add_driver+0x168/0x260 driver_register+0x52/0xc0 do_one_initcall+0x39/0x150 do_init_module+0x56/0x1ef load_module+0x231c/0x2d70 SyS_finit_module+0xa5/0xe0 entry_SYSCALL_64_fastpath+0x1c/0x89 -> #0 (&dev->struct_mutex){+.+.}: __mutex_lock+0x81/0x9b0 i915_mutex_lock_interruptible+0x47/0x130 [i915] i915_gem_fault+0x201/0x790 [i915] __do_fault+0x15/0x70 __handle_mm_fault+0x677/0xdc0 handle_mm_fault+0x14f/0x2f0 __do_page_fault+0x2d1/0x560 page_fault+0x4c/0x60 other info that might help us debug this: Chain exists of: &dev->struct_mutex --> &sb->s_type->i_mutex_key#3 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&sb->s_type->i_mutex_key#3); lock(&mm->mmap_sem); lock(&dev->struct_mutex); *** DEADLOCK *** 1 lock held by debugfs_test/1388: #0: (&mm->mmap_sem){++++}, at: [<0000000029a9c131>] __do_page_fault+0x106/0x560 stack backtrace: CPU: 2 PID: 1388 Comm: debugfs_test Not tainted 4.15.0-rc6-CI-Patchwork_7614+ #1 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./J4205-ITX, BIOS P1.10 09/29/2016 Call Trace: dump_stack+0x5f/0x86 print_circular_bug.isra.18+0x1d0/0x2c0 __lock_acquire+0x14ae/0x1b60 ? lock_acquire+0xaf/0x200 lock_acquire+0xaf/0x200 ? i915_mutex_lock_interruptible+0x47/0x130 [i915] __mutex_lock+0x81/0x9b0 ? i915_mutex_lock_interruptible+0x47/0x130 [i915] ? i915_mutex_lock_interruptible+0x47/0x130 [i915] ? i915_mutex_lock_interruptible+0x47/0x130 [i915] i915_mutex_lock_interruptible+0x47/0x130 [i915] ? __pm_runtime_resume+0x4f/0x80 i915_gem_fault+0x201/0x790 [i915] __do_fault+0x15/0x70 ? _raw_spin_unlock+0x29/0x40 __handle_mm_fault+0x677/0xdc0 handle_mm_fault+0x14f/0x2f0 __do_page_fault+0x2d1/0x560 ? page_fault+0x36/0x60 page_fault+0x4c/0x60 v2: Added lock protection to guc->log.runtime.relay_chan (Chris) Fixed locking inside guc_flush_logs uncovered by new lockdep. v3: Locking guc_read_update_log_buffer entirely with relay_lock. (Chris) Prepared intel_guc_init_early. Moved relay_lock inside relay_create relay_destroy, relay_file_create, guc_read_update_log_buffer. (Michal) Removed struct_mutex lock around guc_log_flush and removed usage of guc_log_has_relay() from runtime_create path as it needs struct_mutex lock. v4: Handle NULL relay sub buffer pointer earlier in read_update_log_buffer (Chris). Fixed comment suffix **/. (Michal) Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104693 Testcase: igt/debugfs_test/read_all_entries # with enable_guc=1 and guc_log_level=1 Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Marta Lofstedt <marta.lofstedt@intel.com> Cc: Michal Winiarski <michal.winiarski@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/1516808821-3638-3-git-send-email-sagar.a.kamble@intel.com
2018-01-24 08:46:58 -07:00
/*
* While we're using plain log level in i915, GuC controls are much more...
* "elaborate"? We have a couple of bits for verbosity, separate bit for actual
* log enabling, and separate bit for default logging - which "conveniently"
* ignores the enable bit.
*/
#define GUC_LOG_LEVEL_DISABLED 0
#define GUC_LOG_LEVEL_NON_VERBOSE 1
#define GUC_LOG_LEVEL_IS_ENABLED(x) ((x) > GUC_LOG_LEVEL_DISABLED)
#define GUC_LOG_LEVEL_IS_VERBOSE(x) ((x) > GUC_LOG_LEVEL_NON_VERBOSE)
#define GUC_LOG_LEVEL_TO_VERBOSITY(x) ({ \
typeof(x) _x = (x); \
GUC_LOG_LEVEL_IS_VERBOSE(_x) ? _x - 2 : 0; \
})
#define GUC_VERBOSITY_TO_LOG_LEVEL(x) ((x) + 2)
#define GUC_LOG_LEVEL_MAX GUC_VERBOSITY_TO_LOG_LEVEL(GUC_LOG_VERBOSITY_MAX)
struct intel_guc_log {
u32 level;
struct i915_vma *vma;
struct {
void *buf_addr;
struct workqueue_struct *flush_wq;
struct work_struct flush_work;
struct rchan *channel;
struct mutex lock;
u32 full_count;
} relay;
/* logging related stats */
struct {
u32 sampled_overflow;
u32 overflow;
u32 flush;
} stats[GUC_MAX_LOG_BUFFER];
};
void intel_guc_log_init_early(struct intel_guc_log *log);
int intel_guc_log_create(struct intel_guc_log *log);
void intel_guc_log_destroy(struct intel_guc_log *log);
int intel_guc_log_set_level(struct intel_guc_log *log, u32 level);
bool intel_guc_log_relay_enabled(const struct intel_guc_log *log);
int intel_guc_log_relay_open(struct intel_guc_log *log);
void intel_guc_log_relay_flush(struct intel_guc_log *log);
void intel_guc_log_relay_close(struct intel_guc_log *log);
void intel_guc_log_handle_flush_event(struct intel_guc_log *log);
static inline u32 intel_guc_log_get_level(struct intel_guc_log *log)
{
return log->level;
}
#endif