drm/i915/pmu: Do not use colons or dashes in PMU names

We use PCI device path in the registered PMU name in order to distinguish
between multiple GPUs. But since tools/perf reserves a special meaning to
dash and colon characters we need to transliterate them to something else.
We choose an underscore.

v2:
 * Use strreplace. (Chris)
 * Dashes are not good either. (Chris)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reported-by: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Fixes: 05488673 ("drm/i915/pmu: Support multiple GPUs")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110113253.12535-1-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/i915_pmu.c

@@ -1117,12 +1117,17 @@ void i915_pmu_register(struct drm_i915_private *i915)
 	hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	pmu->timer.function = i915_sample;
 
-	if (!is_igp(i915))
+	if (!is_igp(i915)) {
 		pmu->name = kasprintf(GFP_KERNEL,
-				      "i915-%s",
+				      "i915_%s",
 				      dev_name(i915->drm.dev));
-	else
+		if (pmu->name) {
+			/* tools/perf reserves colons as special. */
+			strreplace((char *)pmu->name, ':', '_');
+		}
+	} else {
 		pmu->name = "i915";
+	}
 	if (!pmu->name)
 		goto err;