drm/xe: Introduce fault injection for gt reset

To trigger gt reset failure:
 echo 100 >  /sys/kernel/debug/dri/<cardX>/fail_gt_reset/probability
 echo 2 >  /sys/kernel/debug/dri/<cardX>/fail_gt_reset/times

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
index 491506a1e12e531ff9ad43381016e60095ea5b86..2de8a0b9da1834f8e82655d21a5b605d09af9301 100644 (file)
--- a/drivers/gpu/drm/xe/xe_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_debugfs.c
@@ -5,6 +5,7 @@
 
 #include "xe_debugfs.h"
 
+#include <linux/fault-inject.h>
 #include <linux/string_helpers.h>
 
 #include <drm/drm_debugfs.h>
@@ -20,6 +21,10 @@
 #include "xe_vm.h"
 #endif
 
+#ifdef CONFIG_FAULT_INJECTION
+DECLARE_FAULT_ATTR(gt_reset_failure);
+#endif
+
 static struct xe_device *node_to_xe(struct drm_info_node *node)
 {
        return to_xe_device(node->minor->dev);
@@ -135,4 +140,9 @@ void xe_debugfs_register(struct xe_device *xe)
 
        for_each_gt(gt, xe, id)
                xe_gt_debugfs_register(gt);
+
+#ifdef CONFIG_FAULT_INJECTION
+       fault_create_debugfs_attr("fail_gt_reset", root, &gt_reset_failure);
+#endif
+
 }

diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
index 82b98740407064c7fc846da4ab5c69f6536a71eb..28bf577c7bf2eaee5d2646dd852cfa2ba6d4d07b 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt.c
+++ b/drivers/gpu/drm/xe/xe_gt.c
@@ -524,6 +524,11 @@ static int gt_reset(struct xe_gt *gt)
 
        xe_gt_info(gt, "reset started\n");
 
+       if (xe_fault_inject_gt_reset()) {
+               err = -ECANCELED;
+               goto err_fail;
+       }
+
        xe_gt_sanitize(gt);
 
        xe_device_mem_access_get(gt_to_xe(gt));
@@ -562,6 +567,7 @@ err_out:
 err_msg:
        XE_WARN_ON(xe_uc_start(&gt->uc));
        xe_device_mem_access_put(gt_to_xe(gt));
+err_fail:
        xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
 
        /* Notify userspace about gt reset failure */
@@ -583,7 +589,7 @@ void xe_gt_reset_async(struct xe_gt *gt)
        xe_gt_info(gt, "trying reset\n");
 
        /* Don't do a reset while one is already in flight */
-       if (xe_uc_reset_prepare(&gt->uc))
+       if (!xe_fault_inject_gt_reset() && xe_uc_reset_prepare(&gt->uc))
                return;
 
        xe_gt_info(gt, "reset queued\n");

diff --git a/drivers/gpu/drm/xe/xe_gt.h b/drivers/gpu/drm/xe/xe_gt.h
index 7298653a73de3c9ae7c0e910bd45a721f37b55e0..caded203a8a03558729f6375aebc42718ea273bf 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt.h
+++ b/drivers/gpu/drm/xe/xe_gt.h
@@ -7,6 +7,7 @@
 #define _XE_GT_H_
 
 #include <drm/drm_util.h>
+#include <linux/fault-inject.h>
 
 #include "xe_device_types.h"
 #include "xe_hw_engine.h"
@@ -16,6 +17,19 @@
                for_each_if(((hwe__) = (gt__)->hw_engines + (id__)) && \
                          xe_hw_engine_is_valid((hwe__)))
 
+#ifdef CONFIG_FAULT_INJECTION
+extern struct fault_attr gt_reset_failure;
+static inline bool xe_fault_inject_gt_reset(void)
+{
+       return should_fail(&gt_reset_failure, 1);
+}
+#else
+static inline bool xe_fault_inject_gt_reset(void)
+{
+       return false;
+}
+#endif
+
 struct xe_gt *xe_gt_alloc(struct xe_tile *tile);
 int xe_gt_init_early(struct xe_gt *gt);
 int xe_gt_init(struct xe_gt *gt);