drm/i915: Add i915 perf infrastructure
Adds base i915 perf infrastructure for Gen performance metrics.
This adds a DRM_IOCTL_I915_PERF_OPEN ioctl that takes an array of uint64
properties to configure a stream of metrics and returns a new fd usable
with standard VFS system calls including read() to read typed and sized
records; ioctl() to enable or disable capture and poll() to wait for
data.
A stream is opened something like:
uint64_t properties[] = {
/* Single context sampling */
DRM_I915_PERF_PROP_CTX_HANDLE, ctx_handle,
/* Include OA reports in samples */
DRM_I915_PERF_PROP_SAMPLE_OA, true,
/* OA unit configuration */
DRM_I915_PERF_PROP_OA_METRICS_SET, metrics_set_id,
DRM_I915_PERF_PROP_OA_FORMAT, report_format,
DRM_I915_PERF_PROP_OA_EXPONENT, period_exponent,
};
struct drm_i915_perf_open_param parm = {
.flags = I915_PERF_FLAG_FD_CLOEXEC |
I915_PERF_FLAG_FD_NONBLOCK |
I915_PERF_FLAG_DISABLED,
.properties_ptr = (uint64_t)properties,
.num_properties = sizeof(properties) / 16,
};
int fd = drmIoctl(drm_fd, DRM_IOCTL_I915_PERF_OPEN, ¶m);
Records read all start with a common { type, size } header with
DRM_I915_PERF_RECORD_SAMPLE being of most interest. Sample records
contain an extensible number of fields and it's the
DRM_I915_PERF_PROP_SAMPLE_xyz properties given when opening that
determine what's included in every sample.
No specific streams are supported yet so any attempt to open a stream
will return an error.
v2:
use i915_gem_context_get() - Chris Wilson
v3:
update read() interface to avoid passing state struct - Chris Wilson
fix some rebase fallout, with i915-perf init/deinit
v4:
s/DRM_IORW/DRM_IOW/ - Emil Velikov
Signed-off-by: Robert Bragg <robert@sixbynine.org>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Sourab Gupta <sourab.gupta@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161107194957.3385-2-robert@sixbynine.org
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
new file mode 100644
index 0000000..777ce65
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -0,0 +1,449 @@
+/*
+ * Copyright © 2015-2016 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.
+ *
+ * Authors:
+ * Robert Bragg <robert@sixbynine.org>
+ */
+
+#include <linux/anon_inodes.h>
+
+#include "i915_drv.h"
+
+struct perf_open_properties {
+ u32 sample_flags;
+
+ u64 single_context:1;
+ u64 ctx_handle;
+};
+
+static ssize_t i915_perf_read_locked(struct i915_perf_stream *stream,
+ struct file *file,
+ char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ /* Note we keep the offset (aka bytes read) separate from any
+ * error status so that the final check for whether we return
+ * the bytes read with a higher precedence than any error (see
+ * comment below) doesn't need to be handled/duplicated in
+ * stream->ops->read() implementations.
+ */
+ size_t offset = 0;
+ int ret = stream->ops->read(stream, buf, count, &offset);
+
+ /* If we've successfully copied any data then reporting that
+ * takes precedence over any internal error status, so the
+ * data isn't lost.
+ *
+ * For example ret will be -ENOSPC whenever there is more
+ * buffered data than can be copied to userspace, but that's
+ * only interesting if we weren't able to copy some data
+ * because it implies the userspace buffer is too small to
+ * receive a single record (and we never split records).
+ *
+ * Another case with ret == -EFAULT is more of a grey area
+ * since it would seem like bad form for userspace to ask us
+ * to overrun its buffer, but the user knows best:
+ *
+ * http://yarchive.net/comp/linux/partial_reads_writes.html
+ */
+ return offset ?: (ret ?: -EAGAIN);
+}
+
+static ssize_t i915_perf_read(struct file *file,
+ char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct i915_perf_stream *stream = file->private_data;
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+ ssize_t ret;
+
+ if (!(file->f_flags & O_NONBLOCK)) {
+ /* Allow false positives from stream->ops->wait_unlocked.
+ */
+ do {
+ ret = stream->ops->wait_unlocked(stream);
+ if (ret)
+ return ret;
+
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_read_locked(stream, file,
+ buf, count, ppos);
+ mutex_unlock(&dev_priv->perf.lock);
+ } while (ret == -EAGAIN);
+ } else {
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_read_locked(stream, file, buf, count, ppos);
+ mutex_unlock(&dev_priv->perf.lock);
+ }
+
+ return ret;
+}
+
+static unsigned int i915_perf_poll_locked(struct i915_perf_stream *stream,
+ struct file *file,
+ poll_table *wait)
+{
+ unsigned int streams = 0;
+
+ stream->ops->poll_wait(stream, file, wait);
+
+ if (stream->ops->can_read(stream))
+ streams |= POLLIN;
+
+ return streams;
+}
+
+static unsigned int i915_perf_poll(struct file *file, poll_table *wait)
+{
+ struct i915_perf_stream *stream = file->private_data;
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+ int ret;
+
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_poll_locked(stream, file, wait);
+ mutex_unlock(&dev_priv->perf.lock);
+
+ return ret;
+}
+
+static void i915_perf_enable_locked(struct i915_perf_stream *stream)
+{
+ if (stream->enabled)
+ return;
+
+ /* Allow stream->ops->enable() to refer to this */
+ stream->enabled = true;
+
+ if (stream->ops->enable)
+ stream->ops->enable(stream);
+}
+
+static void i915_perf_disable_locked(struct i915_perf_stream *stream)
+{
+ if (!stream->enabled)
+ return;
+
+ /* Allow stream->ops->disable() to refer to this */
+ stream->enabled = false;
+
+ if (stream->ops->disable)
+ stream->ops->disable(stream);
+}
+
+static long i915_perf_ioctl_locked(struct i915_perf_stream *stream,
+ unsigned int cmd,
+ unsigned long arg)
+{
+ switch (cmd) {
+ case I915_PERF_IOCTL_ENABLE:
+ i915_perf_enable_locked(stream);
+ return 0;
+ case I915_PERF_IOCTL_DISABLE:
+ i915_perf_disable_locked(stream);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static long i915_perf_ioctl(struct file *file,
+ unsigned int cmd,
+ unsigned long arg)
+{
+ struct i915_perf_stream *stream = file->private_data;
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+ long ret;
+
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_ioctl_locked(stream, cmd, arg);
+ mutex_unlock(&dev_priv->perf.lock);
+
+ return ret;
+}
+
+static void i915_perf_destroy_locked(struct i915_perf_stream *stream)
+{
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+
+ if (stream->enabled)
+ i915_perf_disable_locked(stream);
+
+ if (stream->ops->destroy)
+ stream->ops->destroy(stream);
+
+ list_del(&stream->link);
+
+ if (stream->ctx) {
+ mutex_lock(&dev_priv->drm.struct_mutex);
+ i915_gem_context_put(stream->ctx);
+ mutex_unlock(&dev_priv->drm.struct_mutex);
+ }
+
+ kfree(stream);
+}
+
+static int i915_perf_release(struct inode *inode, struct file *file)
+{
+ struct i915_perf_stream *stream = file->private_data;
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+
+ mutex_lock(&dev_priv->perf.lock);
+ i915_perf_destroy_locked(stream);
+ mutex_unlock(&dev_priv->perf.lock);
+
+ return 0;
+}
+
+
+static const struct file_operations fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .release = i915_perf_release,
+ .poll = i915_perf_poll,
+ .read = i915_perf_read,
+ .unlocked_ioctl = i915_perf_ioctl,
+};
+
+
+static struct i915_gem_context *
+lookup_context(struct drm_i915_private *dev_priv,
+ struct drm_i915_file_private *file_priv,
+ u32 ctx_user_handle)
+{
+ struct i915_gem_context *ctx;
+ int ret;
+
+ ret = i915_mutex_lock_interruptible(&dev_priv->drm);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ctx = i915_gem_context_lookup(file_priv, ctx_user_handle);
+ if (!IS_ERR(ctx))
+ i915_gem_context_get(ctx);
+
+ mutex_unlock(&dev_priv->drm.struct_mutex);
+
+ return ctx;
+}
+
+static int
+i915_perf_open_ioctl_locked(struct drm_i915_private *dev_priv,
+ struct drm_i915_perf_open_param *param,
+ struct perf_open_properties *props,
+ struct drm_file *file)
+{
+ struct i915_gem_context *specific_ctx = NULL;
+ struct i915_perf_stream *stream = NULL;
+ unsigned long f_flags = 0;
+ int stream_fd;
+ int ret;
+
+ if (props->single_context) {
+ u32 ctx_handle = props->ctx_handle;
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+
+ specific_ctx = lookup_context(dev_priv, file_priv, ctx_handle);
+ if (IS_ERR(specific_ctx)) {
+ ret = PTR_ERR(specific_ctx);
+ if (ret != -EINTR)
+ DRM_ERROR("Failed to look up context with ID %u for opening perf stream\n",
+ ctx_handle);
+ goto err;
+ }
+ }
+
+ if (!specific_ctx && !capable(CAP_SYS_ADMIN)) {
+ DRM_ERROR("Insufficient privileges to open system-wide i915 perf stream\n");
+ ret = -EACCES;
+ goto err_ctx;
+ }
+
+ stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+ if (!stream) {
+ ret = -ENOMEM;
+ goto err_ctx;
+ }
+
+ stream->sample_flags = props->sample_flags;
+ stream->dev_priv = dev_priv;
+ stream->ctx = specific_ctx;
+
+ /*
+ * TODO: support sampling something
+ *
+ * For now this is as far as we can go.
+ */
+ DRM_ERROR("Unsupported i915 perf stream configuration\n");
+ ret = -EINVAL;
+ goto err_alloc;
+
+ list_add(&stream->link, &dev_priv->perf.streams);
+
+ if (param->flags & I915_PERF_FLAG_FD_CLOEXEC)
+ f_flags |= O_CLOEXEC;
+ if (param->flags & I915_PERF_FLAG_FD_NONBLOCK)
+ f_flags |= O_NONBLOCK;
+
+ stream_fd = anon_inode_getfd("[i915_perf]", &fops, stream, f_flags);
+ if (stream_fd < 0) {
+ ret = stream_fd;
+ goto err_open;
+ }
+
+ if (!(param->flags & I915_PERF_FLAG_DISABLED))
+ i915_perf_enable_locked(stream);
+
+ return stream_fd;
+
+err_open:
+ list_del(&stream->link);
+ if (stream->ops->destroy)
+ stream->ops->destroy(stream);
+err_alloc:
+ kfree(stream);
+err_ctx:
+ if (specific_ctx) {
+ mutex_lock(&dev_priv->drm.struct_mutex);
+ i915_gem_context_put(specific_ctx);
+ mutex_unlock(&dev_priv->drm.struct_mutex);
+ }
+err:
+ return ret;
+}
+
+/* Note we copy the properties from userspace outside of the i915 perf
+ * mutex to avoid an awkward lockdep with mmap_sem.
+ *
+ * Note this function only validates properties in isolation it doesn't
+ * validate that the combination of properties makes sense or that all
+ * properties necessary for a particular kind of stream have been set.
+ */
+static int read_properties_unlocked(struct drm_i915_private *dev_priv,
+ u64 __user *uprops,
+ u32 n_props,
+ struct perf_open_properties *props)
+{
+ u64 __user *uprop = uprops;
+ int i;
+
+ memset(props, 0, sizeof(struct perf_open_properties));
+
+ if (!n_props) {
+ DRM_ERROR("No i915 perf properties given");
+ return -EINVAL;
+ }
+
+ /* Considering that ID = 0 is reserved and assuming that we don't
+ * (currently) expect any configurations to ever specify duplicate
+ * values for a particular property ID then the last _PROP_MAX value is
+ * one greater than the maximum number of properties we expect to get
+ * from userspace.
+ */
+ if (n_props >= DRM_I915_PERF_PROP_MAX) {
+ DRM_ERROR("More i915 perf properties specified than exist");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < n_props; i++) {
+ u64 id, value;
+ int ret;
+
+ ret = get_user(id, uprop);
+ if (ret)
+ return ret;
+
+ ret = get_user(value, uprop + 1);
+ if (ret)
+ return ret;
+
+ switch ((enum drm_i915_perf_property_id)id) {
+ case DRM_I915_PERF_PROP_CTX_HANDLE:
+ props->single_context = 1;
+ props->ctx_handle = value;
+ break;
+ default:
+ MISSING_CASE(id);
+ DRM_ERROR("Unknown i915 perf property ID");
+ return -EINVAL;
+ }
+
+ uprop += 2;
+ }
+
+ return 0;
+}
+
+int i915_perf_open_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_i915_perf_open_param *param = data;
+ struct perf_open_properties props;
+ u32 known_open_flags;
+ int ret;
+
+ if (!dev_priv->perf.initialized) {
+ DRM_ERROR("i915 perf interface not available for this system");
+ return -ENOTSUPP;
+ }
+
+ known_open_flags = I915_PERF_FLAG_FD_CLOEXEC |
+ I915_PERF_FLAG_FD_NONBLOCK |
+ I915_PERF_FLAG_DISABLED;
+ if (param->flags & ~known_open_flags) {
+ DRM_ERROR("Unknown drm_i915_perf_open_param flag\n");
+ return -EINVAL;
+ }
+
+ ret = read_properties_unlocked(dev_priv,
+ u64_to_user_ptr(param->properties_ptr),
+ param->num_properties,
+ &props);
+ if (ret)
+ return ret;
+
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_open_ioctl_locked(dev_priv, param, &props, file);
+ mutex_unlock(&dev_priv->perf.lock);
+
+ return ret;
+}
+
+void i915_perf_init(struct drm_i915_private *dev_priv)
+{
+ INIT_LIST_HEAD(&dev_priv->perf.streams);
+ mutex_init(&dev_priv->perf.lock);
+
+ dev_priv->perf.initialized = true;
+}
+
+void i915_perf_fini(struct drm_i915_private *dev_priv)
+{
+ if (!dev_priv->perf.initialized)
+ return;
+
+ /* Currently nothing to clean up */
+
+ dev_priv->perf.initialized = false;
+}