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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpu/drm/i915/gt/sysfs_engines.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/i915/gt/sysfs_engines.c')
-rw-r--r--drivers/gpu/drm/i915/gt/sysfs_engines.c540
1 files changed, 540 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/sysfs_engines.c b/drivers/gpu/drm/i915/gt/sysfs_engines.c
new file mode 100644
index 000000000..f2d9858d8
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/sysfs_engines.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+
+#include "i915_drv.h"
+#include "intel_engine.h"
+#include "intel_engine_heartbeat.h"
+#include "sysfs_engines.h"
+
+struct kobj_engine {
+ struct kobject base;
+ struct intel_engine_cs *engine;
+};
+
+static struct intel_engine_cs *kobj_to_engine(struct kobject *kobj)
+{
+ return container_of(kobj, struct kobj_engine, base)->engine;
+}
+
+static ssize_t
+name_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", kobj_to_engine(kobj)->name);
+}
+
+static struct kobj_attribute name_attr =
+__ATTR(name, 0444, name_show, NULL);
+
+static ssize_t
+class_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", kobj_to_engine(kobj)->uabi_class);
+}
+
+static struct kobj_attribute class_attr =
+__ATTR(class, 0444, class_show, NULL);
+
+static ssize_t
+inst_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", kobj_to_engine(kobj)->uabi_instance);
+}
+
+static struct kobj_attribute inst_attr =
+__ATTR(instance, 0444, inst_show, NULL);
+
+static ssize_t
+mmio_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "0x%x\n", kobj_to_engine(kobj)->mmio_base);
+}
+
+static struct kobj_attribute mmio_attr =
+__ATTR(mmio_base, 0444, mmio_show, NULL);
+
+static const char * const vcs_caps[] = {
+ [ilog2(I915_VIDEO_CLASS_CAPABILITY_HEVC)] = "hevc",
+ [ilog2(I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC)] = "sfc",
+};
+
+static const char * const vecs_caps[] = {
+ [ilog2(I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC)] = "sfc",
+};
+
+static ssize_t repr_trim(char *buf, ssize_t len)
+{
+ /* Trim off the trailing space and replace with a newline */
+ if (len > PAGE_SIZE)
+ len = PAGE_SIZE;
+ if (len > 0)
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static ssize_t
+__caps_show(struct intel_engine_cs *engine,
+ unsigned long caps, char *buf, bool show_unknown)
+{
+ const char * const *repr;
+ int count, n;
+ ssize_t len;
+
+ switch (engine->class) {
+ case VIDEO_DECODE_CLASS:
+ repr = vcs_caps;
+ count = ARRAY_SIZE(vcs_caps);
+ break;
+
+ case VIDEO_ENHANCEMENT_CLASS:
+ repr = vecs_caps;
+ count = ARRAY_SIZE(vecs_caps);
+ break;
+
+ default:
+ repr = NULL;
+ count = 0;
+ break;
+ }
+ GEM_BUG_ON(count > BITS_PER_LONG);
+
+ len = 0;
+ for_each_set_bit(n, &caps, show_unknown ? BITS_PER_LONG : count) {
+ if (n >= count || !repr[n]) {
+ if (GEM_WARN_ON(show_unknown))
+ len += snprintf(buf + len, PAGE_SIZE - len,
+ "[%x] ", n);
+ } else {
+ len += snprintf(buf + len, PAGE_SIZE - len,
+ "%s ", repr[n]);
+ }
+ if (GEM_WARN_ON(len >= PAGE_SIZE))
+ break;
+ }
+ return repr_trim(buf, len);
+}
+
+static ssize_t
+caps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return __caps_show(engine, engine->uabi_capabilities, buf, true);
+}
+
+static struct kobj_attribute caps_attr =
+__ATTR(capabilities, 0444, caps_show, NULL);
+
+static ssize_t
+all_caps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ return __caps_show(kobj_to_engine(kobj), -1, buf, false);
+}
+
+static struct kobj_attribute all_caps_attr =
+__ATTR(known_capabilities, 0444, all_caps_show, NULL);
+
+static ssize_t
+max_spin_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+ unsigned long long duration, clamped;
+ int err;
+
+ /*
+ * When waiting for a request, if is it currently being executed
+ * on the GPU, we busywait for a short while before sleeping. The
+ * premise is that most requests are short, and if it is already
+ * executing then there is a good chance that it will complete
+ * before we can setup the interrupt handler and go to sleep.
+ * We try to offset the cost of going to sleep, by first spinning
+ * on the request -- if it completed in less time than it would take
+ * to go sleep, process the interrupt and return back to the client,
+ * then we have saved the client some latency, albeit at the cost
+ * of spinning on an expensive CPU core.
+ *
+ * While we try to avoid waiting at all for a request that is unlikely
+ * to complete, deciding how long it is worth spinning is for is an
+ * arbitrary decision: trading off power vs latency.
+ */
+
+ err = kstrtoull(buf, 0, &duration);
+ if (err)
+ return err;
+
+ clamped = intel_clamp_max_busywait_duration_ns(engine, duration);
+ if (duration != clamped)
+ return -EINVAL;
+
+ WRITE_ONCE(engine->props.max_busywait_duration_ns, duration);
+
+ return count;
+}
+
+static ssize_t
+max_spin_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->props.max_busywait_duration_ns);
+}
+
+static struct kobj_attribute max_spin_attr =
+__ATTR(max_busywait_duration_ns, 0644, max_spin_show, max_spin_store);
+
+static ssize_t
+max_spin_default(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->defaults.max_busywait_duration_ns);
+}
+
+static struct kobj_attribute max_spin_def =
+__ATTR(max_busywait_duration_ns, 0444, max_spin_default, NULL);
+
+static ssize_t
+timeslice_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+ unsigned long long duration, clamped;
+ int err;
+
+ /*
+ * Execlists uses a scheduling quantum (a timeslice) to alternate
+ * execution between ready-to-run contexts of equal priority. This
+ * ensures that all users (though only if they of equal importance)
+ * have the opportunity to run and prevents livelocks where contexts
+ * may have implicit ordering due to userspace semaphores.
+ */
+
+ err = kstrtoull(buf, 0, &duration);
+ if (err)
+ return err;
+
+ clamped = intel_clamp_timeslice_duration_ms(engine, duration);
+ if (duration != clamped)
+ return -EINVAL;
+
+ WRITE_ONCE(engine->props.timeslice_duration_ms, duration);
+
+ if (execlists_active(&engine->execlists))
+ set_timer_ms(&engine->execlists.timer, duration);
+
+ return count;
+}
+
+static ssize_t
+timeslice_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->props.timeslice_duration_ms);
+}
+
+static struct kobj_attribute timeslice_duration_attr =
+__ATTR(timeslice_duration_ms, 0644, timeslice_show, timeslice_store);
+
+static ssize_t
+timeslice_default(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->defaults.timeslice_duration_ms);
+}
+
+static struct kobj_attribute timeslice_duration_def =
+__ATTR(timeslice_duration_ms, 0444, timeslice_default, NULL);
+
+static ssize_t
+stop_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+ unsigned long long duration, clamped;
+ int err;
+
+ /*
+ * When we allow ourselves to sleep before a GPU reset after disabling
+ * submission, even for a few milliseconds, gives an innocent context
+ * the opportunity to clear the GPU before the reset occurs. However,
+ * how long to sleep depends on the typical non-preemptible duration
+ * (a similar problem to determining the ideal preempt-reset timeout
+ * or even the heartbeat interval).
+ */
+
+ err = kstrtoull(buf, 0, &duration);
+ if (err)
+ return err;
+
+ clamped = intel_clamp_stop_timeout_ms(engine, duration);
+ if (duration != clamped)
+ return -EINVAL;
+
+ WRITE_ONCE(engine->props.stop_timeout_ms, duration);
+ return count;
+}
+
+static ssize_t
+stop_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->props.stop_timeout_ms);
+}
+
+static struct kobj_attribute stop_timeout_attr =
+__ATTR(stop_timeout_ms, 0644, stop_show, stop_store);
+
+static ssize_t
+stop_default(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->defaults.stop_timeout_ms);
+}
+
+static struct kobj_attribute stop_timeout_def =
+__ATTR(stop_timeout_ms, 0444, stop_default, NULL);
+
+static ssize_t
+preempt_timeout_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+ unsigned long long timeout, clamped;
+ int err;
+
+ /*
+ * After initialising a preemption request, we give the current
+ * resident a small amount of time to vacate the GPU. The preemption
+ * request is for a higher priority context and should be immediate to
+ * maintain high quality of service (and avoid priority inversion).
+ * However, the preemption granularity of the GPU can be quite coarse
+ * and so we need a compromise.
+ */
+
+ err = kstrtoull(buf, 0, &timeout);
+ if (err)
+ return err;
+
+ clamped = intel_clamp_preempt_timeout_ms(engine, timeout);
+ if (timeout != clamped)
+ return -EINVAL;
+
+ WRITE_ONCE(engine->props.preempt_timeout_ms, timeout);
+
+ if (READ_ONCE(engine->execlists.pending[0]))
+ set_timer_ms(&engine->execlists.preempt, timeout);
+
+ return count;
+}
+
+static ssize_t
+preempt_timeout_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->props.preempt_timeout_ms);
+}
+
+static struct kobj_attribute preempt_timeout_attr =
+__ATTR(preempt_timeout_ms, 0644, preempt_timeout_show, preempt_timeout_store);
+
+static ssize_t
+preempt_timeout_default(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->defaults.preempt_timeout_ms);
+}
+
+static struct kobj_attribute preempt_timeout_def =
+__ATTR(preempt_timeout_ms, 0444, preempt_timeout_default, NULL);
+
+static ssize_t
+heartbeat_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+ unsigned long long delay, clamped;
+ int err;
+
+ /*
+ * We monitor the health of the system via periodic heartbeat pulses.
+ * The pulses also provide the opportunity to perform garbage
+ * collection. However, we interpret an incomplete pulse (a missed
+ * heartbeat) as an indication that the system is no longer responsive,
+ * i.e. hung, and perform an engine or full GPU reset. Given that the
+ * preemption granularity can be very coarse on a system, the optimal
+ * value for any workload is unknowable!
+ */
+
+ err = kstrtoull(buf, 0, &delay);
+ if (err)
+ return err;
+
+ clamped = intel_clamp_heartbeat_interval_ms(engine, delay);
+ if (delay != clamped)
+ return -EINVAL;
+
+ err = intel_engine_set_heartbeat(engine, delay);
+ if (err)
+ return err;
+
+ return count;
+}
+
+static ssize_t
+heartbeat_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->props.heartbeat_interval_ms);
+}
+
+static struct kobj_attribute heartbeat_interval_attr =
+__ATTR(heartbeat_interval_ms, 0644, heartbeat_show, heartbeat_store);
+
+static ssize_t
+heartbeat_default(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+ struct intel_engine_cs *engine = kobj_to_engine(kobj);
+
+ return sprintf(buf, "%lu\n", engine->defaults.heartbeat_interval_ms);
+}
+
+static struct kobj_attribute heartbeat_interval_def =
+__ATTR(heartbeat_interval_ms, 0444, heartbeat_default, NULL);
+
+static void kobj_engine_release(struct kobject *kobj)
+{
+ kfree(kobj);
+}
+
+static struct kobj_type kobj_engine_type = {
+ .release = kobj_engine_release,
+ .sysfs_ops = &kobj_sysfs_ops
+};
+
+static struct kobject *
+kobj_engine(struct kobject *dir, struct intel_engine_cs *engine)
+{
+ struct kobj_engine *ke;
+
+ ke = kzalloc(sizeof(*ke), GFP_KERNEL);
+ if (!ke)
+ return NULL;
+
+ kobject_init(&ke->base, &kobj_engine_type);
+ ke->engine = engine;
+
+ if (kobject_add(&ke->base, dir, "%s", engine->name)) {
+ kobject_put(&ke->base);
+ return NULL;
+ }
+
+ /* xfer ownership to sysfs tree */
+ return &ke->base;
+}
+
+static void add_defaults(struct kobj_engine *parent)
+{
+ static const struct attribute *files[] = {
+ &max_spin_def.attr,
+ &stop_timeout_def.attr,
+#if CONFIG_DRM_I915_HEARTBEAT_INTERVAL
+ &heartbeat_interval_def.attr,
+#endif
+ NULL
+ };
+ struct kobj_engine *ke;
+
+ ke = kzalloc(sizeof(*ke), GFP_KERNEL);
+ if (!ke)
+ return;
+
+ kobject_init(&ke->base, &kobj_engine_type);
+ ke->engine = parent->engine;
+
+ if (kobject_add(&ke->base, &parent->base, "%s", ".defaults")) {
+ kobject_put(&ke->base);
+ return;
+ }
+
+ if (sysfs_create_files(&ke->base, files))
+ return;
+
+ if (intel_engine_has_timeslices(ke->engine) &&
+ sysfs_create_file(&ke->base, &timeslice_duration_def.attr))
+ return;
+
+ if (intel_engine_has_preempt_reset(ke->engine) &&
+ sysfs_create_file(&ke->base, &preempt_timeout_def.attr))
+ return;
+}
+
+void intel_engines_add_sysfs(struct drm_i915_private *i915)
+{
+ static const struct attribute *files[] = {
+ &name_attr.attr,
+ &class_attr.attr,
+ &inst_attr.attr,
+ &mmio_attr.attr,
+ &caps_attr.attr,
+ &all_caps_attr.attr,
+ &max_spin_attr.attr,
+ &stop_timeout_attr.attr,
+#if CONFIG_DRM_I915_HEARTBEAT_INTERVAL
+ &heartbeat_interval_attr.attr,
+#endif
+ NULL
+ };
+
+ struct device *kdev = i915->drm.primary->kdev;
+ struct intel_engine_cs *engine;
+ struct kobject *dir;
+
+ dir = kobject_create_and_add("engine", &kdev->kobj);
+ if (!dir)
+ return;
+
+ for_each_uabi_engine(engine, i915) {
+ struct kobject *kobj;
+
+ kobj = kobj_engine(dir, engine);
+ if (!kobj)
+ goto err_engine;
+
+ if (sysfs_create_files(kobj, files))
+ goto err_object;
+
+ if (intel_engine_has_timeslices(engine) &&
+ sysfs_create_file(kobj, &timeslice_duration_attr.attr))
+ goto err_engine;
+
+ if (intel_engine_has_preempt_reset(engine) &&
+ sysfs_create_file(kobj, &preempt_timeout_attr.attr))
+ goto err_engine;
+
+ add_defaults(container_of(kobj, struct kobj_engine, base));
+
+ if (0) {
+err_object:
+ kobject_put(kobj);
+err_engine:
+ dev_err(kdev, "Failed to add sysfs engine '%s'\n",
+ engine->name);
+ break;
+ }
+ }
+}