drm/amdgpu: add pre_asic_init callback for SOC15

We need to restore some registers prior to running asic
init to work around a firmware bug.

Acked-by: Nirmoy Das <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

···
 	return amdgpu_gart_table_vram_alloc(adev);
 }
 
+/**
+ * gmc_v9_0_save_registers - saves regs
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * This saves potential register values that should be
+ * restored upon resume
+ */
+static void gmc_v9_0_save_registers(struct amdgpu_device *adev)
+{
+	if (adev->asic_type == CHIP_RAVEN)
+		adev->gmc.sdpif_register = RREG32_SOC15(DCE, 0, mmDCHUBBUB_SDPIF_MMIO_CNTRL_0);
+}
+
 static int gmc_v9_0_sw_init(void *handle)
 {
 	int r, vram_width = 0, vram_type = 0, vram_vendor = 0;
···
 
 	amdgpu_vm_manager_init(adev);
 
+	gmc_v9_0_save_registers(adev);
+
 	return 0;
 }
 
···
  *
  * This restores register values, saved at suspend.
  */
-static void gmc_v9_0_restore_registers(struct amdgpu_device *adev)
+void gmc_v9_0_restore_registers(struct amdgpu_device *adev)
 {
 	if (adev->asic_type == CHIP_RAVEN)
 		WREG32_SOC15(DCE, 0, mmDCHUBBUB_SDPIF_MMIO_CNTRL_0, adev->gmc.sdpif_register);
···
 }
 
 /**
- * gmc_v9_0_save_registers - saves regs
- *
- * @adev: amdgpu_device pointer
- *
- * This saves potential register values that should be
- * restored upon resume
- */
-static void gmc_v9_0_save_registers(struct amdgpu_device *adev)
-{
-	if (adev->asic_type == CHIP_RAVEN)
-		adev->gmc.sdpif_register = RREG32_SOC15(DCE, 0, mmDCHUBBUB_SDPIF_MMIO_CNTRL_0);
-}
-
-/**
  * gmc_v9_0_gart_disable - gart disable
  *
  * @adev: amdgpu_device pointer
···
 	if (r)
 		return r;
 
-	gmc_v9_0_save_registers(adev);
-
 	return 0;
 }
 
···
 	int r;
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
-	gmc_v9_0_restore_registers(adev);
 	r = gmc_v9_0_hw_init(adev);
 	if (r)
 		return r;

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.h

···
 
 extern const struct amd_ip_funcs gmc_v9_0_ip_funcs;
 extern const struct amdgpu_ip_block_version gmc_v9_0_ip_block;
+
+void gmc_v9_0_restore_registers(struct amdgpu_device *adev);
 #endif

drivers/gpu/drm/amd/amdgpu/soc15.c

···
 	return (nak_r + nak_g);
 }
 
+static void soc15_pre_asic_init(struct amdgpu_device *adev)
+{
+	gmc_v9_0_restore_registers(adev);
+}
+
 static const struct amdgpu_asic_funcs soc15_asic_funcs =
 {
 	.read_disabled_bios = &soc15_read_disabled_bios,
···
 	.need_reset_on_init = &soc15_need_reset_on_init,
 	.get_pcie_replay_count = &soc15_get_pcie_replay_count,
 	.supports_baco = &soc15_supports_baco,
+	.pre_asic_init = &soc15_pre_asic_init,
 };
 
 static const struct amdgpu_asic_funcs vega20_asic_funcs =
···
 	.need_reset_on_init = &soc15_need_reset_on_init,
 	.get_pcie_replay_count = &soc15_get_pcie_replay_count,
 	.supports_baco = &soc15_supports_baco,
+	.pre_asic_init = &soc15_pre_asic_init,
 };
 
 static int soc15_common_early_init(void *handle)