[PATCH i-g-t 1/2] lib/xe_eudebug: Introduce preempt_timeout helpers

[Dominik Karol Piątkowski]

This patch introduces preempt_timeout helpers:
 - xe_eudebug_set_preempt_timeout_to_max
   Sets preempt_timeout_us for given engine_class to maximum.
 - xe_eudebug_restore_preempt_timeout
   Sets preempt_timeout_us for given engine_class to previous value.

Signed-off-by: Dominik Karol Piątkowski <dominik.karol.piatkowski at intel.com>
---
 lib/xe/xe_eudebug.c | 120 ++++++++++++++++++++++++++++++++++++++++++++
 lib/xe/xe_eudebug.h |   3 ++
 2 files changed, 123 insertions(+)

diff --git a/lib/xe/xe_eudebug.c b/lib/xe/xe_eudebug.c
index 2c7cd2ae1..229f9e6a1 100644
--- a/lib/xe/xe_eudebug.c
+++ b/lib/xe/xe_eudebug.c
@@ -16,6 +16,7 @@
 #include "intel_pat.h"
 #include "xe_eudebug.h"
 #include "xe_ioctl.h"
+#include "xe_drm.h"
 
 struct event_trigger {
 	xe_eudebug_trigger_fn fn;
@@ -1717,6 +1718,125 @@ bool xe_eudebug_enable(int fd, bool enable)
 	return old;
 }
 
+/**
+ * xe_eudebug_set_preempt_timeout_to_max
+ * @fd: xe client
+ * @engine_class: engine class to modify (drm_xe_engine_class_instance->engine_class)
+ * @value: pointer to variable to store previous preempt_timeout value in, needed for restore
+ *
+ * Sets preempt_timeout_us for given engine_class to maximum.
+ *
+ * Returns: true on success, false on failure.
+ */
+bool xe_eudebug_set_preempt_timeout_to_max(int fd, uint16_t engine_class, uint32_t *value)
+{
+	int engines_fd;
+	int gt_fd;
+	uint32_t max_value;
+
+	igt_assert(engine_class == DRM_XE_ENGINE_CLASS_RENDER ||
+		   engine_class == DRM_XE_ENGINE_CLASS_COMPUTE);
+
+	gt_fd = xe_sysfs_gt_open(fd, 0);
+	if (gt_fd == -1) {
+		igt_debug("Failed to open gt.\n");
+
+		return false;
+	}
+
+	if (engine_class == DRM_XE_ENGINE_CLASS_RENDER)
+		engines_fd = openat(gt_fd, "engines/rcs", O_RDONLY);
+	else
+		engines_fd = openat(gt_fd, "engines/ccs", O_RDONLY);
+
+	if (engines_fd == -1) {
+		igt_debug("Failed to open engine class.\n");
+		close(gt_fd);
+
+		return false;
+	}
+
+	if (!__igt_sysfs_get_u32(engines_fd, "preempt_timeout_us", value)) {
+		igt_debug("Failed to read preempt_timeout_us.\n");
+		close(engines_fd);
+		close(gt_fd);
+
+		return false;
+	}
+
+	if (!__igt_sysfs_get_u32(engines_fd, "preempt_timeout_max", &max_value)) {
+		igt_debug("Failed to read preempt_timeout_max.\n");
+		close(engines_fd);
+		close(gt_fd);
+
+		return false;
+	}
+
+	if (!__igt_sysfs_set_u32(engines_fd, "preempt_timeout_us", max_value)) {
+		igt_debug("Failed to write preempt_timeout_us.\n");
+		close(engines_fd);
+		close(gt_fd);
+
+		return false;
+	}
+
+	close(engines_fd);
+	close(gt_fd);
+
+	return true;
+}
+
+/**
+ * xe_eudebug_restore_preempt_timeout
+ * @fd: xe client
+ * @engine_class: engine class to modify (drm_xe_engine_class_instance->engine_class)
+ * @value: previous preempt_timeout value
+ *
+ * Sets preempt_timeout_us for given engine_class to previous value.
+ *
+ * Returns: true on success, false on failure.
+ */
+bool xe_eudebug_restore_preempt_timeout(int fd, uint16_t engine_class, uint32_t value)
+{
+	int engines_fd;
+	int gt_fd;
+
+	igt_assert(engine_class == DRM_XE_ENGINE_CLASS_RENDER ||
+		   engine_class == DRM_XE_ENGINE_CLASS_COMPUTE);
+
+	gt_fd = xe_sysfs_gt_open(fd, 0);
+	if (gt_fd == -1) {
+		igt_debug("Failed to open gt.\n");
+
+		return false;
+	}
+
+	if (engine_class == DRM_XE_ENGINE_CLASS_RENDER)
+		engines_fd = openat(gt_fd, "engines/rcs", O_RDONLY);
+	else
+		engines_fd = openat(gt_fd, "engines/ccs", O_RDONLY);
+
+	if (engines_fd == -1) {
+		igt_debug("Failed to open engine class.\n");
+		close(gt_fd);
+
+		return false;
+	}
+
+	if (!__igt_sysfs_set_u32(engines_fd, "preempt_timeout_us", value)) {
+		igt_debug("Failed to write preempt_timeout_us.\n");
+		close(engines_fd);
+		close(gt_fd);
+
+		return false;
+	}
+
+	close(engines_fd);
+	close(gt_fd);
+
+	return true;
+}
+
 /* Eu debugger wrappers around resource creating xe ioctls. */
 
 /**
diff --git a/lib/xe/xe_eudebug.h b/lib/xe/xe_eudebug.h
index 29ab68fee..144035862 100644
--- a/lib/xe/xe_eudebug.h
+++ b/lib/xe/xe_eudebug.h
@@ -167,6 +167,9 @@ void xe_eudebug_client_set_data(struct xe_eudebug_client *c, void *ptr);
 
 bool xe_eudebug_enable(int fd, bool enable);
 
+bool xe_eudebug_set_preempt_timeout_to_max(int fd, uint16_t engine_class, uint32_t *value);
+bool xe_eudebug_restore_preempt_timeout(int fd, uint16_t engine_class, uint32_t value);
+
 int xe_eudebug_client_open_driver(struct xe_eudebug_client *c);
 void xe_eudebug_client_close_driver(struct xe_eudebug_client *c, int fd);
 uint32_t xe_eudebug_client_vm_create(struct xe_eudebug_client *c, int fd,
-- 
2.34.1