drm/amdgpu/kfd: Add shared SDMA reset functionality with callback support

This patch introduces shared SDMA reset functionality between AMDGPU and KFD.
The implementation includes the following key changes:

1. Added `amdgpu_sdma_reset_queue`:
   - Resets a specific SDMA queue by instance ID.
   - Invokes registered pre-reset and post-reset callbacks to allow KFD and AMDGPU
     to save/restore their state during the reset process.

2. Added `amdgpu_set_on_reset_callbacks`:
   - Allows KFD and AMDGPU to register callback functions for pre-reset and
     post-reset operations.
   - Callbacks are stored in a global linked list and invoked in the correct order
     during SDMA reset.

This patch ensures that both AMDGPU and KFD can handle SDMA reset events
gracefully, with proper state saving and restoration. It also provides a flexible
callback mechanism for future extensions.

v2: fix CamelCase and put the SDMA helper into amdgpu_sdma.c (Alex)

v3: rename the `amdgpu_register_on_reset_callbacks` function to
      `amdgpu_sdma_register_on_reset_callbacks`
    move global reset_callback_list to struct amdgpu_sdma (Alex)

v4: Update the reset callback function description and
   rename the reset function to amdgpu_sdma_reset_engine (Alex)

Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Suggested-by: Jiadong Zhu <Jiadong.Zhu@amd.com>
Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
index 174badca27e7d457de939cdfd4bbfaf24c3877df..fe39198307ec553f401fb822c8c22f63f75a8397 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
@@ -460,3 +460,76 @@ void amdgpu_sdma_sysfs_reset_mask_fini(struct amdgpu_device *adev)
                        device_remove_file(adev->dev, &dev_attr_sdma_reset_mask);
        }
 }
+
+/**
+ * amdgpu_sdma_register_on_reset_callbacks - Register SDMA reset callbacks
+ * @funcs: Pointer to the callback structure containing pre_reset and post_reset functions
+ *
+ * This function allows KFD and AMDGPU to register their own callbacks for handling
+ * pre-reset and post-reset operations for engine reset. These are needed because engine
+ * reset will stop all queues on that engine.
+ */
+void amdgpu_sdma_register_on_reset_callbacks(struct amdgpu_device *adev, struct sdma_on_reset_funcs *funcs)
+{
+       if (!funcs)
+               return;
+
+       /* Initialize the list node in the callback structure */
+       INIT_LIST_HEAD(&funcs->list);
+
+       /* Add the callback structure to the global list */
+       list_add_tail(&funcs->list, &adev->sdma.reset_callback_list);
+}
+
+/**
+ * amdgpu_sdma_reset_engine - Reset a specific SDMA engine
+ * @adev: Pointer to the AMDGPU device
+ * @instance_id: ID of the SDMA engine instance to reset
+ *
+ * This function performs the following steps:
+ * 1. Calls all registered pre_reset callbacks to allow KFD and AMDGPU to save their state.
+ * 2. Resets the specified SDMA engine instance.
+ * 3. Calls all registered post_reset callbacks to allow KFD and AMDGPU to restore their state.
+ *
+ * Returns: 0 on success, or a negative error code on failure.
+ */
+int amdgpu_sdma_reset_engine(struct amdgpu_device *adev, uint32_t instance_id)
+{
+       struct sdma_on_reset_funcs *funcs;
+       int ret;
+
+       /* Invoke all registered pre_reset callbacks */
+       list_for_each_entry(funcs, &adev->sdma.reset_callback_list, list) {
+               if (funcs->pre_reset) {
+                       ret = funcs->pre_reset(adev, instance_id);
+                       if (ret) {
+                               dev_err(adev->dev,
+                               "beforeReset callback failed for instance %u: %d\n",
+                                       instance_id, ret);
+                               return ret;
+                       }
+               }
+       }
+
+       /* Perform the SDMA reset for the specified instance */
+       ret = amdgpu_dpm_reset_sdma(adev, 1 << instance_id);
+       if (ret) {
+               dev_err(adev->dev, "Failed to reset SDMA instance %u\n", instance_id);
+               return ret;
+       }
+
+       /* Invoke all registered post_reset callbacks */
+       list_for_each_entry(funcs, &adev->sdma.reset_callback_list, list) {
+               if (funcs->post_reset) {
+                       ret = funcs->post_reset(adev, instance_id);
+                       if (ret) {
+                               dev_err(adev->dev,
+                               "afterReset callback failed for instance %u: %d\n",
+                                       instance_id, ret);
+                               return ret;
+                       }
+               }
+       }
+
+       return 0;
+}

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
index 5f60736051d1477c73f95aaab24b92af9a3bff57..f91d7584855767ad27315eb7639223a0e44da671 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.h
@@ -98,6 +98,13 @@ struct amdgpu_sdma_ras {
        struct amdgpu_ras_block_object ras_block;
 };
 
+struct sdma_on_reset_funcs {
+       int (*pre_reset)(struct amdgpu_device *adev, uint32_t instance_id);
+       int (*post_reset)(struct amdgpu_device *adev, uint32_t instance_id);
+       /* Linked list node to store this structure in a list; */
+       struct list_head list;
+};
+
 struct amdgpu_sdma {
        struct amdgpu_sdma_instance instance[AMDGPU_MAX_SDMA_INSTANCES];
        struct amdgpu_irq_src   trap_irq;
@@ -118,6 +125,7 @@ struct amdgpu_sdma {
        struct amdgpu_sdma_ras  *ras;
        uint32_t                *ip_dump;
        uint32_t                supported_reset;
+       struct list_head        reset_callback_list;
 };
 
 /*
@@ -157,6 +165,9 @@ struct amdgpu_buffer_funcs {
                                 uint32_t byte_count);
 };
 
+void amdgpu_sdma_register_on_reset_callbacks(struct amdgpu_device *adev, struct sdma_on_reset_funcs *funcs);
+int amdgpu_sdma_reset_engine(struct amdgpu_device *adev, uint32_t instance_id);
+
 #define amdgpu_emit_copy_buffer(adev, ib, s, d, b, t) (adev)->mman.buffer_funcs->emit_copy_buffer((ib),  (s), (d), (b), (t))
 #define amdgpu_emit_fill_buffer(adev, ib, s, d, b) (adev)->mman.buffer_funcs->emit_fill_buffer((ib), (s), (d), (b))
 

diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
index 9925b183c07f7872d4553021e93486708321f728..aab9e9fe0cb821c221c2317016344377cd87fdfe 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
@@ -1477,7 +1477,7 @@ static int sdma_v4_4_2_sw_init(struct amdgpu_ip_block *ip_block)
        r = amdgpu_sdma_sysfs_reset_mask_init(adev);
        if (r)
                return r;
-
+       INIT_LIST_HEAD(&adev->sdma.reset_callback_list);
        return r;
 }