Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ccdf6341 authored by Robert Bragg's avatar Robert Bragg Committed by Daniel Vetter
Browse files

drm/i915: Add dev.i915.perf_stream_paranoid sysctl option 



Consistent with the kernel.perf_event_paranoid sysctl option that can
allow non-root users to access system wide cpu metrics, this can
optionally allow non-root users to access system wide OA counter metrics
from Gen graphics hardware.

Signed-off-by: default avatarRobert Bragg <robert@sixbynine.org>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarSourab Gupta <sourab.gupta@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161107194957.3385-9-robert@sixbynine.org
parent 442b8c06

drivers/gpu/drm/i915/i915_drv.h

+1 −0
Original line number Diff line number Diff line
@@ -2194,6 +2194,7 @@ struct drm_i915_private { 
		bool initialized;



		struct kobject *metrics_kobj;

		struct ctl_table_header *sysctl_header;



		struct mutex lock;

		struct list_head streams;

drivers/gpu/drm/i915/i915_perf.c

+49 −1
Original line number Diff line number Diff line
@@ -64,6 +64,11 @@ 
#define POLL_FREQUENCY 200

#define POLL_PERIOD (NSEC_PER_SEC / POLL_FREQUENCY)



/* for sysctl proc_dointvec_minmax of dev.i915.perf_stream_paranoid */

static int zero;

static int one = 1;

static u32 i915_perf_stream_paranoid = true;



/* The maximum exponent the hardware accepts is 63 (essentially it selects one

 * of the 64bit timestamp bits to trigger reports from) but there's currently

 * no known use case for sampling as infrequently as once per 47 thousand years.
@@ -1207,7 +1212,13 @@ i915_perf_open_ioctl_locked(struct drm_i915_private *dev_priv, 
		}

	}



	if (!specific_ctx && !capable(CAP_SYS_ADMIN)) {

	/* Similar to perf's kernel.perf_paranoid_cpu sysctl option

	 * we check a dev.i915.perf_stream_paranoid sysctl option

	 * to determine if it's ok to access system wide OA counters

	 * without CAP_SYS_ADMIN privileges.

	 */

	if (!specific_ctx &&

	    i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) {

		DRM_ERROR("Insufficient privileges to open system-wide i915 perf stream\n");

		ret = -EACCES;

		goto err_ctx;
@@ -1460,6 +1471,39 @@ void i915_perf_unregister(struct drm_i915_private *dev_priv) 
	dev_priv->perf.metrics_kobj = NULL;

}



static struct ctl_table oa_table[] = {

	{

	 .procname = "perf_stream_paranoid",

	 .data = &i915_perf_stream_paranoid,

	 .maxlen = sizeof(i915_perf_stream_paranoid),

	 .mode = 0644,

	 .proc_handler = proc_dointvec_minmax,

	 .extra1 = &zero,

	 .extra2 = &one,

	 },

	{}

};



static struct ctl_table i915_root[] = {

	{

	 .procname = "i915",

	 .maxlen = 0,

	 .mode = 0555,

	 .child = oa_table,

	 },

	{}

};



static struct ctl_table dev_root[] = {

	{

	 .procname = "dev",

	 .maxlen = 0,

	 .mode = 0555,

	 .child = i915_root,

	 },

	{}

};



void i915_perf_init(struct drm_i915_private *dev_priv)

{

	if (!IS_HASWELL(dev_priv))
@@ -1490,6 +1534,8 @@ void i915_perf_init(struct drm_i915_private *dev_priv) 
	dev_priv->perf.oa.n_builtin_sets =

		i915_oa_n_builtin_metric_sets_hsw;



	dev_priv->perf.sysctl_header = register_sysctl_table(dev_root);



	dev_priv->perf.initialized = true;

}
@@ -1498,6 +1544,8 @@ void i915_perf_fini(struct drm_i915_private *dev_priv) 
	if (!dev_priv->perf.initialized)

		return;



	unregister_sysctl_table(dev_priv->perf.sysctl_header);



	memset(&dev_priv->perf.oa.ops, 0, sizeof(dev_priv->perf.oa.ops));

	dev_priv->perf.initialized = false;

}