@@ -94,6 +94,9 @@ i915-y += dvo_ch7017.o \
# virtual gpu code
i915-y += i915_vgpu.o
+# perf code
+i915-y += i915_perf.o
+
# legacy horrors
i915-y += i915_dma.o
@@ -1012,6 +1012,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
if (ret < 0)
goto out_free_priv;
+ /* Must at least be initialized before trying to pin any context
+ * which i915_perf hooks into.
+ */
+ i915_perf_init(dev);
+
intel_pm_setup(dev);
intel_runtime_pm_get(dev_priv);
@@ -1203,6 +1208,7 @@ int i915_driver_unload(struct drm_device *dev)
return ret;
}
+ i915_perf_fini(dev);
intel_power_domains_fini(dev_priv);
intel_gpu_ips_teardown();
@@ -1379,6 +1385,7 @@ const struct drm_ioctl_desc i915_ioctls[] = {
DRM_IOCTL_DEF_DRV(I915_GEM_USERPTR, i915_gem_userptr_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_GETPARAM, i915_gem_context_getparam_ioctl, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_SETPARAM, i915_gem_context_setparam_ioctl, DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF_DRV(I915_PERF_OPEN, i915_perf_open_ioctl, DRM_RENDER_ALLOW),
};
int i915_max_ioctl = ARRAY_SIZE(i915_ioctls);
@@ -1732,6 +1732,81 @@ struct intel_wm_config {
bool sprites_scaled;
};
+struct i915_perf_read_state {
+ int count;
+ ssize_t read;
+ char __user *buf;
+};
+
+struct i915_perf_stream {
+ struct drm_i915_private *dev_priv;
+
+ struct list_head link;
+
+ u32 sample_flags;
+
+ struct intel_context *ctx;
+ bool enabled;
+
+ /* Enables the collection of HW samples, either in response to
+ * I915_PERF_IOCTL_ENABLE or implicitly called when stream is
+ * opened without I915_PERF_FLAG_DISABLED.
+ */
+ void (*enable)(struct i915_perf_stream *stream);
+
+ /* Disables the collection of HW samples, either in response to
+ * I915_PERF_IOCTL_DISABLE or implicitly called before
+ * destroying the stream.
+ */
+ void (*disable)(struct i915_perf_stream *stream);
+
+ /* Return: true if any i915 perf records are ready to read()
+ * for this stream.
+ */
+ bool (*can_read)(struct i915_perf_stream *stream);
+
+ /* Call poll_wait, passing a wait queue that will be woken
+ * once there is something ready to read() for the stream
+ */
+ void (*poll_wait)(struct i915_perf_stream *stream,
+ struct file *file,
+ poll_table *wait);
+
+ /* For handling a blocking read, wait until there is something
+ * to ready to read() for the stream. E.g. wait on the same
+ * wait queue that would be passed to poll_wait() until
+ * ->can_read() returns true (if its safe to call ->can_read()
+ * without the i915 perf lock held).
+ */
+ int (*wait_unlocked)(struct i915_perf_stream *stream);
+
+ /* Copy as many buffered i915 perf samples and records for
+ * this stream to userspace as will fit in the given buffer.
+ *
+ * Only write complete records.
+ *
+ * read_state->count is the length of read_state->buf
+ *
+ * Update read_state->read with the number of bytes written.
+ *
+ * Return: the number of records appended (may be zero if not
+ * enough space), or errno.
+ *
+ * Only return an EFAULT from copying to the userspace buffer
+ * if zero records have been appended, otherwise squash the
+ * EFAULT error and report what records were successfully
+ * copied.
+ */
+ int (*read)(struct i915_perf_stream *stream,
+ struct i915_perf_read_state *read_state);
+
+ /* Cleanup any stream specific resources.
+ *
+ * The stream will always be disabled before this is called.
+ */
+ void (*destroy)(struct i915_perf_stream *stream);
+};
+
struct drm_i915_private {
struct drm_device *dev;
struct kmem_cache *objects;
@@ -1983,6 +2058,12 @@ struct drm_i915_private {
struct i915_runtime_pm pm;
+ struct {
+ bool initialized;
+ struct mutex lock;
+ struct list_head streams;
+ } perf;
+
/* Abstract the submission mechanism (legacy ringbuffer or execlists) away */
struct {
int (*execbuf_submit)(struct i915_execbuffer_params *params,
@@ -3251,6 +3332,9 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
+int i915_perf_open_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file);
+
/* i915_gem_evict.c */
int __must_check i915_gem_evict_something(struct drm_device *dev,
struct i915_address_space *vm,
@@ -3366,6 +3450,10 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
u32 batch_len,
bool is_master);
+/* i915_perf.c */
+extern void i915_perf_init(struct drm_device *dev);
+extern void i915_perf_fini(struct drm_device *dev);
+
/* i915_suspend.c */
extern int i915_save_state(struct drm_device *dev);
extern int i915_restore_state(struct drm_device *dev);
new file mode 100644
@@ -0,0 +1,442 @@
+/*
+ * Copyright © 2015 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/anon_inodes.h>
+#include <linux/sizes.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)
+{
+ struct drm_i915_private *dev_priv = stream->dev_priv;
+ struct i915_perf_read_state state = { count, 0, buf };
+ int ret;
+
+ if (file->f_flags & O_NONBLOCK) {
+ if (!stream->can_read(stream))
+ return -EAGAIN;
+ } else {
+ mutex_unlock(&dev_priv->perf.lock);
+ ret = stream->wait_unlocked(stream);
+ mutex_lock(&dev_priv->perf.lock);
+
+ if (ret)
+ return ret;
+ }
+
+ ret = stream->read(stream, &state);
+ if (ret < 0) {
+ /* can relax this later if needs be, but this is the only
+ * errno expected here atm...
+ */
+ WARN_ON(ret != -EFAULT);
+ return ret;
+ }
+
+ if (ret == 0)
+ return -ENOSPC;
+
+ return state.read;
+}
+
+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;
+
+ 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->poll_wait(stream, file, wait);
+
+ if (stream->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->enable() to refer to this */
+ stream->enabled = true;
+
+ if (stream->enable)
+ stream->enable(stream);
+}
+
+static void i915_perf_disable_locked(struct i915_perf_stream *stream)
+{
+ if (!stream->enabled)
+ return;
+
+ /* Allow stream->disable() to refer to this */
+ stream->enabled = false;
+
+ if (stream->disable)
+ stream->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->destroy)
+ stream->destroy(stream);
+
+ list_del(&stream->link);
+
+ if (stream->ctx) {
+ mutex_lock(&dev_priv->dev->struct_mutex);
+ i915_gem_context_unreference(stream->ctx);
+ mutex_unlock(&dev_priv->dev->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 intel_context *
+lookup_context(struct drm_i915_private *dev_priv,
+ struct file *user_filp,
+ u32 ctx_user_handle)
+{
+ struct intel_context *ctx;
+
+ mutex_lock(&dev_priv->dev->struct_mutex);
+ list_for_each_entry(ctx, &dev_priv->context_list, link) {
+ struct drm_file *drm_file;
+
+ if (!ctx->file_priv)
+ continue;
+
+ drm_file = ctx->file_priv->file;
+
+ if (user_filp->private_data == drm_file &&
+ ctx->user_handle == ctx_user_handle) {
+ i915_gem_context_reference(ctx);
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+
+ return ctx;
+ }
+ }
+ mutex_unlock(&dev_priv->dev->struct_mutex);
+
+ return NULL;
+}
+
+int i915_perf_open_ioctl_locked(struct drm_device *dev,
+ struct drm_i915_perf_open_param *param,
+ struct perf_open_properties *props,
+ struct drm_file *file)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_context *specific_ctx = NULL;
+ struct i915_perf_stream *stream = NULL;
+ unsigned long f_flags = 0;
+ int stream_fd;
+ int ret = 0;
+
+ if (props->single_context) {
+ u32 ctx_handle = props->ctx_handle;
+
+ specific_ctx = lookup_context(dev_priv, file->filp, ctx_handle);
+ if (!specific_ctx) {
+ DRM_ERROR("Failed to look up context with ID %u for opening perf stream\n",
+ ctx_handle);
+ ret = -EINVAL;
+ 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->destroy)
+ stream->destroy(stream);
+err_alloc:
+ kfree(stream);
+err_ctx:
+ if (specific_ctx) {
+ mutex_lock(&dev_priv->dev->struct_mutex);
+ i915_gem_context_unreference(specific_ctx);
+ mutex_unlock(&dev_priv->dev->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;
+ }
+
+ 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, (u64 __user *)uprop);
+ if (ret)
+ return ret;
+
+ if (id == 0 || id >= DRM_I915_PERF_PROP_MAX) {
+ DRM_ERROR("Unknown i915 perf property ID");
+ return -EINVAL;
+ }
+
+ ret = get_user(value, (u64 __user *)uprop + 1);
+ if (ret)
+ return ret;
+
+ switch ((enum drm_i915_perf_property_id)id) {
+ case DRM_I915_PERF_CTX_HANDLE_PROP:
+ props->single_context = 1;
+ props->ctx_handle = value;
+ break;
+
+ case DRM_I915_PERF_PROP_MAX:
+ BUG();
+ }
+
+ 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 = 0;
+ 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,
+ to_user_ptr(param->properties),
+ param->n_properties,
+ &props);
+ if (ret)
+ return ret;
+
+ mutex_lock(&dev_priv->perf.lock);
+ ret = i915_perf_open_ioctl_locked(dev, param, &props, file);
+ mutex_unlock(&dev_priv->perf.lock);
+
+ return ret;
+}
+
+void i915_perf_init(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = to_i915(dev);
+
+ INIT_LIST_HEAD(&dev_priv->perf.streams);
+ mutex_init(&dev_priv->perf.lock);
+
+ dev_priv->perf.initialized = true;
+}
+
+void i915_perf_fini(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = to_i915(dev);
+
+ if (!dev_priv->perf.initialized)
+ return;
+
+ /* Currently nothing to clean up */
+
+ dev_priv->perf.initialized = false;
+}
@@ -230,6 +230,7 @@ typedef struct _drm_i915_sarea {
#define DRM_I915_GEM_USERPTR 0x33
#define DRM_I915_GEM_CONTEXT_GETPARAM 0x34
#define DRM_I915_GEM_CONTEXT_SETPARAM 0x35
+#define DRM_I915_PERF_OPEN 0x36
#define DRM_IOCTL_I915_INIT DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
#define DRM_IOCTL_I915_FLUSH DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -283,6 +284,7 @@ typedef struct _drm_i915_sarea {
#define DRM_IOCTL_I915_GEM_USERPTR DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_USERPTR, struct drm_i915_gem_userptr)
#define DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_GETPARAM, struct drm_i915_gem_context_param)
#define DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_SETPARAM, struct drm_i915_gem_context_param)
+#define DRM_IOCTL_I915_PERF_OPEN DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_PERF_OPEN, struct drm_i915_perf_open_param)
/* Allow drivers to submit batchbuffers directly to hardware, relying
* on the security mechanisms provided by hardware.
@@ -1170,4 +1172,71 @@ struct drm_i915_gem_context_param {
__u64 value;
};
+#define I915_PERF_FLAG_FD_CLOEXEC (1<<0)
+#define I915_PERF_FLAG_FD_NONBLOCK (1<<1)
+#define I915_PERF_FLAG_DISABLED (1<<2)
+
+enum drm_i915_perf_property_id {
+ /**
+ * Open the stream for a specific context handle (as used with
+ * execbuffer2). A stream opened for a specific context this way
+ * won't typically require root privileges.
+ */
+ DRM_I915_PERF_CTX_HANDLE_PROP = 1,
+
+ DRM_I915_PERF_PROP_MAX /* non-ABI */
+};
+
+struct drm_i915_perf_open_param {
+ /** CLOEXEC, NONBLOCK... */
+ __u32 flags;
+
+ /**
+ * Pointer to array of u64 (id, value) pairs configuring the stream
+ * to open.
+ */
+ __u64 __user properties;
+
+ /** The number of u64 (id, value) pairs */
+ __u32 n_properties;
+};
+
+#define I915_PERF_IOCTL_ENABLE _IO('i', 0x0)
+#define I915_PERF_IOCTL_DISABLE _IO('i', 0x1)
+
+/**
+ * Common to all i915 perf records
+ */
+struct drm_i915_perf_record_header {
+ __u32 type;
+ __u16 pad;
+ __u16 size;
+};
+
+enum drm_i915_perf_record_type {
+
+ /**
+ * Samples are the work horse record type whose contents are extensible
+ * and defined when opening an i915 perf stream based on the given
+ * properties.
+ *
+ * Boolean properties following the naming convention
+ * DRM_I915_PERF_SAMPLE_xyz_PROP request the inclusion of 'xyz' data in
+ * every sample.
+ *
+ * The order of these sample properties given by userspace has no
+ * affect on the ordering of data within a sample. The order will be
+ * documented here.
+ *
+ * struct {
+ * struct drm_i915_perf_record_header header;
+ *
+ * TODO: itemize extensible sample data here
+ * };
+ */
+ DRM_I915_PERF_RECORD_SAMPLE = 1,
+
+ DRM_I915_PERF_RECORD_MAX /* non-ABI */
+};
+
#endif /* _UAPI_I915_DRM_H_ */
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_CTX_HANDLE_PROP, ctx_handle, /* Include OA reports in samples */ DRM_I915_PERF_SAMPLE_OA_PROP, true, /* OA unit configuration */ DRM_I915_PERF_OA_METRICS_SET_PROP, metrics_set_id, DRM_I915_PERF_OA_FORMAT_PROP, report_format, DRM_I915_PERF_OA_EXPONENT_PROP, 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 = properties, .n_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_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. Signed-off-by: Robert Bragg <robert@sixbynine.org> --- drivers/gpu/drm/i915/Makefile | 3 + drivers/gpu/drm/i915/i915_dma.c | 7 + drivers/gpu/drm/i915/i915_drv.h | 88 ++++++++ drivers/gpu/drm/i915/i915_perf.c | 442 +++++++++++++++++++++++++++++++++++++++ include/uapi/drm/i915_drm.h | 69 ++++++ 5 files changed, 609 insertions(+) create mode 100644 drivers/gpu/drm/i915/i915_perf.c