intel_guc_log.c
/*
* 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.
*
*/
#include <linux/debugfs.h>
#include <linux/relay.h>
#include "intel_guc_log.h"
#include "i915_drv.h"
static void guc_log_capture_logs(struct intel_guc *guc);
/**
* DOC: GuC firmware log
*
* Firmware log is enabled by setting i915.guc_log_level to non-negative level.
* Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
* i915_guc_load_status will print out firmware loading status and scratch
* registers value.
*
*/
static int guc_log_flush_complete(struct intel_guc *guc)
{
u32 action[] = {
INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE
};
return intel_guc_send(guc, action, ARRAY_SIZE(action));
}
static int guc_log_flush(struct intel_guc *guc)
{
u32 action[] = {
INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
0
};
return intel_guc_send(guc, action, ARRAY_SIZE(action));
}
static int guc_log_control(struct intel_guc *guc, u32 control_val)
{
u32 action[] = {
INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
control_val
};
return intel_guc_send(guc, action, ARRAY_SIZE(action));
}
/*
* Sub buffer switch callback. Called whenever relay has to switch to a new
* sub buffer, relay stays on the same sub buffer if 0 is returned.
*/
static int subbuf_start_callback(struct rchan_buf *buf,
void *subbuf,
void *prev_subbuf,
size_t prev_padding)
{
/* Use no-overwrite mode by default, where relay will stop accepting
* new data if there are no empty sub buffers left.
* There is no strict synchronization enforced by relay between Consumer
* and Producer. In overwrite mode, there is a possibility of getting
* inconsistent/garbled data, the producer could be writing on to the
* same sub buffer from which Consumer is reading. This can't be avoided
* unless Consumer is fast enough and can always run in tandem with
* Producer.
*/
if (relay_buf_full(buf))
return 0;
return 1;
}
/*
* file_create() callback. Creates relay file in debugfs.
*/
static struct dentry *create_buf_file_callback(const char *filename,
struct dentry *parent,
umode_t mode,
struct rchan_buf *buf,
int *is_global)
{
struct dentry *buf_file;
/* This to enable the use of a single buffer for the relay channel and
* correspondingly have a single file exposed to User, through which
* it can collect the logs in order without any post-processing.
* Need to set 'is_global' even if parent is NULL for early logging.
*/
*is_global = 1;
if (!parent)
return NULL;
/* Not using the channel filename passed as an argument, since for each
* channel relay appends the corresponding CPU number to the filename
* passed in relay_open(). This should be fine as relay just needs a
* dentry of the file associated with the channel buffer and that file's
* name need not be same as the filename passed as an argument.
*/
buf_file = debugfs_create_file("guc_log", mode,
parent, buf, &relay_file_operations);
return buf_file;
}
/*
* file_remove() default callback. Removes relay file in debugfs.
*/
static int remove_buf_file_callback(struct dentry *dentry)
{
debugfs_remove(dentry);
return 0;
}
/* relay channel callbacks */
static struct rchan_callbacks relay_callbacks = {
.subbuf_start = subbuf_start_callback,
.create_buf_file = create_buf_file_callback,
.remove_buf_file = remove_buf_file_callback,
};
static int guc_log_relay_file_create(struct intel_guc *guc)
{
struct drm_i915_private *dev_priv = guc_to_i915(guc);
struct dentry *log_dir;
int ret;
if (i915_modparams.guc_log_level < 0)
return 0;
/* For now create the log file in /sys/kernel/debug/dri/0 dir */
log_dir = dev_priv->drm.primary->debugfs_root;
/* If /sys/kernel/debug/dri/0 location do not exist, then debugfs is
* not mounted and so can't create the relay file.
* The relay API seems to fit well with debugfs only, for availing relay
* there are 3 requirements which can be met for debugfs file only in a
* straightforward/clean manner :-
* i) Need the associated dentry pointer of the file, while opening the
* relay channel.
* ii) Should be able to use 'relay_file_operations' fops for the file.
* iii) Set the 'i_private' field of file's inode to the pointer of
* relay channel buffer.
*/
if (!log_dir) {
DRM_ERROR("Debugfs dir not available yet for GuC log file\n");
return -ENODEV;
}
ret = relay_late_setup_files(guc->log.runtime.relay_chan, "guc_log", log_dir);
if (ret < 0 && ret != -EEXIST) {
DRM_ERROR("Couldn't associate relay chan with file %d\n", ret);
return ret;
}
return 0;
}
static void guc_move_to_next_buf(struct intel_guc *guc)
{
/* Make sure the updates made in the sub buffer are visible when
* Consumer sees the following update to offset inside the sub buffer.
*/
smp_wmb();
/* All data has been written, so now move the offset of sub buffer. */
relay_reserve(guc->log.runtime.relay_chan, guc->log.vma->obj->base.size);
/* Switch to the next sub buffer */
relay_flush(guc->log.runtime.relay_chan);
}
static void *guc_get_write_buffer(struct intel_guc *guc)
{
if (!guc->log.runtime.relay_chan)
return NULL;
/* Just get the base address of a new sub buffer and copy data into it
* ourselves. NULL will be returned in no-overwrite mode, if all sub
* buffers are full. Could have used the relay_write() to indirectly
* copy the data, but that would have been bit convoluted, as we need to
* write to only certain locations inside a sub buffer which cannot be
* done without using relay_reserve() along with relay_write(). So its
* better to use relay_reserve() alone.
*/
return relay_reserve(guc->log.runtime.relay_chan, 0);
}
static bool guc_check_log_buf_overflow(struct intel_guc *guc,
enum guc_log_buffer_type type,
unsigned int full_cnt)
{
unsigned int prev_full_cnt = guc->log.prev_overflow_count[type];
bool overflow = false;
if (full_cnt != prev_full_cnt) {
overflow = true;
guc->log.prev_overflow_count[type] = full_cnt;
guc->log.total_overflow_count[type] += full_cnt - prev_full_cnt;
if (full_cnt < prev_full_cnt) {
/* buffer_full_cnt is a 4 bit counter */
guc->log.total_overflow_count[type] += 16;
}
DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
}
return overflow;
}
static unsigned int guc_get_log_buffer_size(enum guc_log_buffer_type type)
{
switch (type) {
case GUC_ISR_LOG_BUFFER:
return (GUC_LOG_ISR_PAGES + 1) * PAGE_SIZE;
case GUC_DPC_LOG_BUFFER:
return (GUC_LOG_DPC_PAGES + 1) * PAGE_SIZE;
case GUC_CRASH_DUMP_LOG_BUFFER:
return (GUC_LOG_CRASH_PAGES + 1) * PAGE_SIZE;
default:
MISSING_CASE(type);
}
return 0;
}
static void guc_read_update_log_buffer(struct intel_guc *guc)
{
unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
struct guc_log_buffer_state log_buf_state_local;
enum guc_log_buffer_type type;
void *src_data, *dst_data;
bool new_overflow;
if (WARN_ON(!guc->log.runtime.buf_addr))
return;
/* Get the pointer to shared GuC log buffer */
log_buf_state = src_data = guc->log.runtime.buf_addr;
/* Get the pointer to local buffer to store the logs */
log_buf_snapshot_state = dst_data = guc_get_write_buffer(guc);
/* Actual logs are present from the 2nd page */
src_data += PAGE_SIZE;
dst_data += PAGE_SIZE;
for (type = GUC_ISR_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
/* Make a copy of the state structure, inside GuC log buffer
* (which is uncached mapped), on the stack to avoid reading
* from it multiple times.
*/
memcpy(&log_buf_state_local, log_buf_state,
sizeof(struct guc_log_buffer_state));
buffer_size = guc_get_log_buffer_size(type);
read_offset = log_buf_state_local.read_ptr;
write_offset = log_buf_state_local.sampled_write_ptr;
full_cnt = log_buf_state_local.buffer_full_cnt;
/* Bookkeeping stuff */
guc->log.flush_count[type] += log_buf_state_local.flush_to_file;
new_overflow = guc_check_log_buf_overflow(guc, type, full_cnt);
/* Update the state of shared log buffer */
log_buf_state->read_ptr = write_offset;
log_buf_state->flush_to_file = 0;
log_buf_state++;
if (unlikely(!log_buf_snapshot_state))
continue;
/* First copy the state structure in snapshot buffer */
memcpy(log_buf_snapshot_state, &log_buf_state_local,
sizeof(struct guc_log_buffer_state));
/* The write pointer could have been updated by GuC firmware,
* after sending the flush interrupt to Host, for consistency
* set write pointer value to same value of sampled_write_ptr
* in the snapshot buffer.
*/
log_buf_snapshot_state->write_ptr = write_offset;
log_buf_snapshot_state++;
/* Now copy the actual logs. */
if (unlikely(new_overflow)) {
/* copy the whole buffer in case of overflow */
read_offset = 0;
write_offset = buffer_size;
} else if (unlikely((read_offset > buffer_size) ||
(write_offset > buffer_size))) {
DRM_ERROR("invalid log buffer state\n");
/* copy whole buffer as offsets are unreliable */
read_offset = 0;
write_offset = buffer_size;
}
/* Just copy the newly written data */
if (read_offset > write_offset) {
i915_memcpy_from_wc(dst_data, src_data, write_offset);
bytes_to_copy = buffer_size - read_offset;
} else {
bytes_to_copy = write_offset - read_offset;
}
i915_memcpy_from_wc(dst_data + read_offset,
src_data + read_offset, bytes_to_copy);
src_data += buffer_size;
dst_data += buffer_size;
}
if (log_buf_snapshot_state)
guc_move_to_next_buf(guc);
else {
/* Used rate limited to avoid deluge of messages, logs might be
* getting consumed by User at a slow rate.
*/
DRM_ERROR_RATELIMITED("no sub-buffer to capture logs\n");
guc->log.capture_miss_count++;
}
}
static void capture_logs_work(struct work_struct *work)
{
struct intel_guc *guc =
container_of(work, struct intel_guc, log.runtime.flush_work);
guc_log_capture_logs(guc);
}
static bool guc_log_has_runtime(struct intel_guc *guc)
{
return guc->log.runtime.buf_addr != NULL;
}
static int guc_log_runtime_create(struct intel_guc *guc)
{
struct drm_i915_private *dev_priv = guc_to_i915(guc);
void *vaddr;
struct rchan *guc_log_relay_chan;
size_t n_subbufs, subbuf_size;
int ret;
lockdep_assert_held(&dev_priv->drm.struct_mutex);
GEM_BUG_ON(guc_log_has_runtime(guc));
ret = i915_gem_object_set_to_wc_domain(guc->log.vma->obj, true);
if (ret)
return ret;
/* Create a WC (Uncached for read) vmalloc mapping of log
* buffer pages, so that we can directly get the data
* (up-to-date) from memory.
*/
vaddr = i915_gem_object_pin_map(guc->log.vma->obj, I915_MAP_WC);
if (IS_ERR(vaddr)) {
DRM_ERROR("Couldn't map log buffer pages %d\n", ret);
return PTR_ERR(vaddr);
}
guc->log.runtime.buf_addr = vaddr;
/* Keep the size of sub buffers same as shared log buffer */
subbuf_size = guc->log.vma->obj->base.size;
/* Store up to 8 snapshots, which is large enough to buffer sufficient
* boot time logs and provides enough leeway to User, in terms of
* latency, for consuming the logs from relay. Also doesn't take
* up too much memory.
*/
n_subbufs = 8;
/* Create a relay channel, so that we have buffers for storing
* the GuC firmware logs, the channel will be linked with a file
* later on when debugfs is registered.
*/
guc_log_relay_chan = relay_open(NULL, NULL, subbuf_size,
n_subbufs, &relay_callbacks, dev_priv);
if (!guc_log_relay_chan) {
DRM_ERROR("Couldn't create relay chan for GuC logging\n");
ret = -ENOMEM;
goto err_vaddr;
}
GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
guc->log.runtime.relay_chan = guc_log_relay_chan;
INIT_WORK(&guc->log.runtime.flush_work, capture_logs_work);
/*
* GuC log buffer flush work item has to do register access to
* send the ack to GuC and this work item, if not synced before
* suspend, can potentially get executed after the GFX device is
* suspended.
* By marking the WQ as freezable, we don't have to bother about
* flushing of this work item from the suspend hooks, the pending
* work item if any will be either executed before the suspend
* or scheduled later on resume. This way the handling of work
* item can be kept same between system suspend & rpm suspend.
*/
guc->log.runtime.flush_wq = alloc_ordered_workqueue("i915-guc_log",
WQ_HIGHPRI | WQ_FREEZABLE);
if (!guc->log.runtime.flush_wq) {
DRM_ERROR("Couldn't allocate the wq for GuC logging\n");
ret = -ENOMEM;
goto err_relaychan;
}
return 0;
err_relaychan:
relay_close(guc->log.runtime.relay_chan);
err_vaddr:
i915_gem_object_unpin_map(guc->log.vma->obj);
guc->log.runtime.buf_addr = NULL;
return ret;
}
static void guc_log_runtime_destroy(struct intel_guc *guc)
{
/*
* It's possible that the runtime stuff was never allocated because
* guc_log_level was < 0 at the time
**/
if (!guc_log_has_runtime(guc))
return;
destroy_workqueue(guc->log.runtime.flush_wq);
relay_close(guc->log.runtime.relay_chan);
i915_gem_object_unpin_map(guc->log.vma->obj);
guc->log.runtime.buf_addr = NULL;
}
static int guc_log_late_setup(struct intel_guc *guc)
{
struct drm_i915_private *dev_priv = guc_to_i915(guc);
int ret;
lockdep_assert_held(&dev_priv->drm.struct_mutex);
if (!guc_log_has_runtime(guc)) {
/* If log_level was set as -1 at boot time, then setup needed to
* handle log buffer flush interrupts would not have been done yet,
* so do that now.
*/
ret = guc_log_runtime_create(guc);
if (ret)
goto err;
}
ret = guc_log_relay_file_create(guc);
if (ret)
goto err_runtime;
return 0;
err_runtime:
guc_log_runtime_destroy(guc);
err:
/* logging will remain off */
i915_modparams.guc_log_level = -1;
return ret;
}
static void guc_log_capture_logs(struct intel_guc *guc)
{
struct drm_i915_private *dev_priv = guc_to_i915(guc);
guc_read_update_log_buffer(guc);
/* Generally device is expected to be active only at this
* time, so get/put should be really quick.
*/
intel_runtime_pm_get(dev_priv);
guc_log_flush_complete(guc);
intel_runtime_pm_put(dev_priv);
}
static void guc_flush_logs(struct intel_guc *guc)
{
struct drm_i915_private *dev_priv = guc_to_i915(guc);
if (!i915_modparams.enable_guc_submission ||
(i915_modparams.guc_log_level < 0))
return;
/* First disable the interrupts, will be renabled afterwards */
gen9_disable_guc_interrupts(dev_priv);
/* Before initiating the forceful flush, wait for any pending/ongoing
* flush to complete otherwise forceful flush may not actually happen.
*/
flush_work(&guc->log.runtime.flush_work);
/* Ask GuC to update the log buffer state */
guc_log_flush(guc);
/* GuC would have updated log buffer by now, so capture it */
guc_log_capture_logs(guc);
}
int intel_guc_log_create(struct intel_guc *guc)
{
struct i915_vma *vma;
unsigned long offset;
u32 flags;
u32 size;
int ret;
GEM_BUG_ON(guc->log.vma);
if (i915_modparams.guc_log_level > GUC_LOG_VERBOSITY_MAX)
i915_modparams.guc_log_level = GUC_LOG_VERBOSITY_MAX;
/* The first page is to save log buffer state. Allocate one
* extra page for others in case for overlap */
size = (1 + GUC_LOG_DPC_PAGES + 1 +
GUC_LOG_ISR_PAGES + 1 +
GUC_LOG_CRASH_PAGES + 1) << PAGE_SHIFT;
/* We require SSE 4.1 for fast reads from the GuC log buffer and
* it should be present on the chipsets supporting GuC based
* submisssions.
*/
if (WARN_ON(!i915_has_memcpy_from_wc())) {
ret = -EINVAL;
goto err;
}
vma = intel_guc_allocate_vma(guc, size);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto err;
}
guc->log.vma = vma;
if (i915_modparams.guc_log_level >= 0) {
ret = guc_log_runtime_create(guc);
if (ret < 0)
goto err_vma;
}
/* each allocated unit is a page */
flags = GUC_LOG_VALID | GUC_LOG_NOTIFY_ON_HALF_FULL |
(GUC_LOG_DPC_PAGES << GUC_LOG_DPC_SHIFT) |
(GUC_LOG_ISR_PAGES << GUC_LOG_ISR_SHIFT) |
(GUC_LOG_CRASH_PAGES << GUC_LOG_CRASH_SHIFT);
offset = guc_ggtt_offset(vma) >> PAGE_SHIFT; /* in pages */
guc->log.flags = (offset << GUC_LOG_BUF_ADDR_SHIFT) | flags;
return 0;
err_vma:
i915_vma_unpin_and_release(&guc->log.vma);
err:
/* logging will be off */
i915_modparams.guc_log_level = -1;
return ret;
}
void intel_guc_log_destroy(struct intel_guc *guc)
{
guc_log_runtime_destroy(guc);
i915_vma_unpin_and_release(&guc->log.vma);
}
int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val)
{
struct intel_guc *guc = &dev_priv->guc;
union guc_log_control log_param;
int ret;
log_param.value = control_val;
if (log_param.verbosity < GUC_LOG_VERBOSITY_MIN ||
log_param.verbosity > GUC_LOG_VERBOSITY_MAX)
return -EINVAL;
/* This combination doesn't make sense & won't have any effect */
if (!log_param.logging_enabled && (i915_modparams.guc_log_level < 0))
return 0;
ret = guc_log_control(guc, log_param.value);
if (ret < 0) {
DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
return ret;
}
if (log_param.logging_enabled) {
i915_modparams.guc_log_level = log_param.verbosity;
/* If log_level was set as -1 at boot time, then the relay channel file
* wouldn't have been created by now and interrupts also would not have
* been enabled. Try again now, just in case.
*/
ret = guc_log_late_setup(guc);
if (ret < 0) {
DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
return ret;
}
/* GuC logging is currently the only user of Guc2Host interrupts */
gen9_enable_guc_interrupts(dev_priv);
} else {
/* Once logging is disabled, GuC won't generate logs & send an
* interrupt. But there could be some data in the log buffer
* which is yet to be captured. So request GuC to update the log
* buffer state and then collect the left over logs.
*/
guc_flush_logs(guc);
/* As logging is disabled, update log level to reflect that */
i915_modparams.guc_log_level = -1;
}
return ret;
}
void i915_guc_log_register(struct drm_i915_private *dev_priv)
{
if (!i915_modparams.enable_guc_submission ||
(i915_modparams.guc_log_level < 0))
return;
mutex_lock(&dev_priv->drm.struct_mutex);
guc_log_late_setup(&dev_priv->guc);
mutex_unlock(&dev_priv->drm.struct_mutex);
}
void i915_guc_log_unregister(struct drm_i915_private *dev_priv)
{
if (!i915_modparams.enable_guc_submission)
return;
mutex_lock(&dev_priv->drm.struct_mutex);
/* GuC logging is currently the only user of Guc2Host interrupts */
gen9_disable_guc_interrupts(dev_priv);
guc_log_runtime_destroy(&dev_priv->guc);
mutex_unlock(&dev_priv->drm.struct_mutex);
}