[PATCH 2/4] drm/amdgpu/sdma: Refactor SDMA reset functionality and add callback support

[<jesse.zhang@amd.com>]

From: "Jesse.zhang@amd.com" <Jesse.zhang@amd.com>

This patch refactors the SDMA reset functionality in the `sdma_v4_4_2` driver
to improve modularity and support shared usage between AMDGPU and KFD. The
changes include:

1. **Refactored SDMA Reset Logic**:
   - Split the `sdma_v4_4_2_reset_queue` function into two separate functions:
     - `sdma_v4_4_2_stop_queue`: Stops the SDMA queue before reset.
     - `sdma_v4_4_2_restore_queue`: Restores the SDMA queue after reset.
   - These functions are now used as callbacks for the shared reset mechanism.

2. **Added Callback Support**:
   - Introduced a new structure `sdma_v4_4_2_reset_funcs` to hold the stop and
     restore callbacks.
   - Added `sdma_v4_4_2_set_reset_funcs` to register these callbacks with the
     shared reset mechanism using `amdgpu_set_on_reset_callbacks`.

3. **Fixed Reset Queue Function**:
   - Modified `sdma_v4_4_2_reset_queue` to use the shared `amdgpu_sdma_reset_queue`
     function, ensuring consistency across the driver.

This patch ensures that SDMA reset functionality is more modular, reusable, and
aligned with the shared reset mechanism between AMDGPU and KFD.

Suggested-by: Jiadong Zhu <Jiadong.Zhu@amd.com>
Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 32 +++++++++++++++++++++---
 1 file changed, 28 insertions(+), 4 deletions(-)

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 64c163dd708f..3e60456b0db0 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c
@@ -105,6 +105,7 @@ static void sdma_v4_4_2_set_buffer_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_vm_pte_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_irq_funcs(struct amdgpu_device *adev);
 static void sdma_v4_4_2_set_ras_funcs(struct amdgpu_device *adev);
+static void sdma_v4_4_2_set_reset_funcs(struct amdgpu_device *adev);
 
 static u32 sdma_v4_4_2_get_reg_offset(struct amdgpu_device *adev,
 		u32 instance, u32 offset)
@@ -1330,6 +1331,7 @@ static int sdma_v4_4_2_early_init(struct amdgpu_ip_block *ip_block)
 	sdma_v4_4_2_set_vm_pte_funcs(adev);
 	sdma_v4_4_2_set_irq_funcs(adev);
 	sdma_v4_4_2_set_ras_funcs(adev);
+	sdma_v4_4_2_set_reset_funcs(adev);
 
 	return 0;
 }
@@ -1605,8 +1607,14 @@ static int sdma_v4_4_2_soft_reset(struct amdgpu_ip_block *ip_block)
 static int sdma_v4_4_2_reset_queue(struct amdgpu_ring *ring, unsigned int vmid)
 {
 	struct amdgpu_device *adev = ring->adev;
-	int i, r;
+	u32 id = GET_INST(SDMA0, ring->me);
+	return amdgpu_sdma_reset_instance(adev, id);
+}
+
+static int sdma_v4_4_2_stop_queue(struct amdgpu_device *adev, uint32_t instance_id)
+{
 	u32 inst_mask;
+	struct amdgpu_ring *ring = &adev->sdma.instance[instance_id].ring;
 
 	if (amdgpu_sriov_vf(adev))
 		return -EINVAL;
@@ -1617,10 +1625,16 @@ static int sdma_v4_4_2_reset_queue(struct amdgpu_ring *ring, unsigned int vmid)
 	if (adev->sdma.has_page_queue)
 		sdma_v4_4_2_inst_page_stop(adev, inst_mask);
 
-	r = amdgpu_dpm_reset_sdma(adev, 1 << GET_INST(SDMA0, ring->me));
-	if (r)
-		return r;
+	return 0;
+}
 
+static int sdma_v4_4_2_restore_queue(struct amdgpu_device *adev, uint32_t instance_id)
+{
+	int i;
+	u32 inst_mask;
+	struct amdgpu_ring *ring = &adev->sdma.instance[instance_id].ring;
+
+	inst_mask = 1 << ring->me;
 	udelay(50);
 
 	for (i = 0; i < adev->usec_timeout; i++) {
@@ -1638,6 +1652,16 @@ static int sdma_v4_4_2_reset_queue(struct amdgpu_ring *ring, unsigned int vmid)
 	return sdma_v4_4_2_inst_start(adev, inst_mask, true);
 }
 
+static struct sdma_on_reset_funcs sdma_v4_4_2_reset_funcs = {
+	.pre_reset = sdma_v4_4_2_stop_queue,
+	.post_reset = sdma_v4_4_2_restore_queue,
+};
+
+static void sdma_v4_4_2_set_reset_funcs(struct amdgpu_device *adev)
+{
+	amdgpu_sdma_register_on_reset_callbacks(adev, &sdma_v4_4_2_reset_funcs);
+}
+
 static int sdma_v4_4_2_set_trap_irq_state(struct amdgpu_device *adev,
 					struct amdgpu_irq_src *source,
 					unsigned type,
-- 
2.25.1