drm/i915/perf: always consider holding preemption a privileged op

The ordering of the checks in the existing code can lead to holding
preemption not being considered as privileged op.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 84de59d7deeb ("drm/i915/perf: allow holding preemption on filtered ctx")
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191111095308.2550-1-lionel.g.landwerlin@intel.com
(cherry picked from commit 0b0120d4c7b013eba59b33254febc0a6e4049e13)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index a8c2318d3d5edfd2611a9f516511ee25b808dbc3..00317ea19a4afb31ef12ac61f61e034626770489 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -3307,15 +3307,6 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
                }
        }
 
-       if (props->hold_preemption) {
-               if (!props->single_context) {
-                       DRM_DEBUG("preemption disable with no context\n");
-                       ret = -EINVAL;
-                       goto err;
-               }
-               privileged_op = true;
-       }
-
        /*
         * On Haswell the OA unit supports clock gating off for a specific
         * context and in this mode there's no visibility of metrics for the
@@ -3335,12 +3326,21 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf,
         * doesn't request global stream access (i.e. query based sampling
         * using MI_RECORD_PERF_COUNT.
         */
-       if (IS_HASWELL(perf->i915) && specific_ctx && !props->hold_preemption)
+       if (IS_HASWELL(perf->i915) && specific_ctx)
                privileged_op = false;
        else if (IS_GEN(perf->i915, 12) && specific_ctx &&
                 (props->sample_flags & SAMPLE_OA_REPORT) == 0)
                privileged_op = false;
 
+       if (props->hold_preemption) {
+               if (!props->single_context) {
+                       DRM_DEBUG("preemption disable with no context\n");
+                       ret = -EINVAL;
+                       goto err;
+               }
+               privileged_op = true;
+       }
+
        /* 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