[PATCH 2/2] drm/amdgpu: add work function for GPU reset event

[Shashank Sharma]

From: Shashank Sharma <shashank.sharma at amd.com>

This patch adds a work function, which will get scheduled
in event of a GPU reset, and will send a uevent to user with
some reset context infomration, like a PID and some flags.

The userspace can do some recovery and post-processing work
based on this event.

V2:
- Changed the name of the work to gpu_reset_event_work
  (Christian)
- Added a structure to accommodate some additional information
  (like a PID and some flags)

Cc: Alexander Deucher <alexander.deucher at amd.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  7 +++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index d8b854fcbffa..7df219fe363f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -813,6 +813,11 @@ struct amd_powerplay {
 #define AMDGPU_RESET_MAGIC_NUM 64
 #define AMDGPU_MAX_DF_PERFMONS 4
 #define AMDGPU_PRODUCT_NAME_LEN 64
+struct amdgpu_reset_event_ctx {
+	uint64_t pid;
+	uint32_t flags;
+};
+
 struct amdgpu_device {
 	struct device			*dev;
 	struct pci_dev			*pdev;
@@ -1063,6 +1068,7 @@ struct amdgpu_device {
 
 	int asic_reset_res;
 	struct work_struct		xgmi_reset_work;
+	struct work_struct		gpu_reset_event_work;
 	struct list_head		reset_list;
 
 	long				gfx_timeout;
@@ -1097,6 +1103,7 @@ struct amdgpu_device {
 	pci_channel_state_t		pci_channel_state;
 
 	struct amdgpu_reset_control     *reset_cntl;
+	struct amdgpu_reset_event_ctx   reset_event_ctx;
 	uint32_t                        ip_versions[MAX_HWIP][HWIP_MAX_INSTANCE];
 
 	bool				ram_is_direct_mapped;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index ed077de426d9..c43d099da06d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -73,6 +73,7 @@
 #include <linux/pm_runtime.h>
 
 #include <drm/drm_drv.h>
+#include <drm/drm_sysfs.h>
 
 MODULE_FIRMWARE("amdgpu/vega10_gpu_info.bin");
 MODULE_FIRMWARE("amdgpu/vega12_gpu_info.bin");
@@ -3277,6 +3278,23 @@ bool amdgpu_device_has_dc_support(struct amdgpu_device *adev)
 	return amdgpu_device_asic_has_dc_support(adev->asic_type);
 }
 
+static void amdgpu_device_reset_event_func(struct work_struct *__work)
+{
+	struct amdgpu_device *adev = container_of(__work, struct amdgpu_device,
+						  gpu_reset_event_work);
+	struct amdgpu_reset_event_ctx *event_ctx = &adev->reset_event_ctx;
+
+	/*
+	 * A GPU reset has happened, indicate the userspace and pass the
+	 * following information:
+	 *	- pid of the process involved,
+	 *	- if the VRAM is valid or not,
+	 *	- indicate that userspace may want to collect the ftrace event
+	 * data from the trace event.
+	 */
+	drm_sysfs_reset_event(&adev->ddev, event_ctx->pid, event_ctx->flags);
+}
+
 static void amdgpu_device_xgmi_reset_func(struct work_struct *__work)
 {
 	struct amdgpu_device *adev =
@@ -3525,6 +3543,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 			  amdgpu_device_delay_enable_gfx_off);
 
 	INIT_WORK(&adev->xgmi_reset_work, amdgpu_device_xgmi_reset_func);
+	INIT_WORK(&adev->gpu_reset_event_work, amdgpu_device_reset_event_func);
 
 	adev->gfx.gfx_off_req_count = 1;
 	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
-- 
2.32.0