drm/amdgpu: add interface for setting ASPM

Support NAVI10 ASPM setting.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -87,6 +87,8 @@ struct amdgpu_nbio_funcs {
 	void (*query_ras_error_count)(struct amdgpu_device *adev,
 					void *ras_error_status);
 	int (*ras_late_init)(struct amdgpu_device *adev);
+	void (*enable_aspm)(struct amdgpu_device *adev,
+			    bool enable);
 };
 
 struct amdgpu_nbio {

drivers/gpu/drm/amd/amdgpu/nbio_v2_3.c

@@ -28,10 +28,12 @@
 #include "nbio/nbio_2_3_offset.h"
 #include "nbio/nbio_2_3_sh_mask.h"
 #include <uapi/linux/kfd_ioctl.h>
+#include <linux/pci.h>
 
 #define smnPCIE_CONFIG_CNTL	0x11180044
 #define smnCPM_CONTROL		0x11180460
 #define smnPCIE_CNTL2		0x11180070
+#define smnPCIE_LC_CNTL		0x11140280
 
 #define mmBIF_SDMA2_DOORBELL_RANGE		0x01d6
 #define mmBIF_SDMA2_DOORBELL_RANGE_BASE_IDX	2
@@ -312,6 +314,42 @@ static void nbio_v2_3_init_registers(struct amdgpu_device *adev)
 		WREG32_PCIE(smnPCIE_CONFIG_CNTL, data);
 }
 
+#define NAVI10_PCIE__LC_L0S_INACTIVITY_DEFAULT		0x00000000 // off by default, no gains over L1
+#define NAVI10_PCIE__LC_L1_INACTIVITY_DEFAULT		0x00000009 // 1=1us, 9=1ms
+#define NAVI10_PCIE__LC_L1_INACTIVITY_TBT_DEFAULT	0x0000000E // 4ms
+
+static void nbio_v2_3_enable_aspm(struct amdgpu_device *adev,
+				  bool enable)
+{
+	uint32_t def, data;
+
+	def = data = RREG32_PCIE(smnPCIE_LC_CNTL);
+
+	if (enable) {
+		/* Disable ASPM L0s/L1 first */
+		data &= ~(PCIE_LC_CNTL__LC_L0S_INACTIVITY_MASK | PCIE_LC_CNTL__LC_L1_INACTIVITY_MASK);
+
+		data |= NAVI10_PCIE__LC_L0S_INACTIVITY_DEFAULT << PCIE_LC_CNTL__LC_L0S_INACTIVITY__SHIFT;
+
+		if (pci_is_thunderbolt_attached(adev->pdev))
+			data |= NAVI10_PCIE__LC_L1_INACTIVITY_TBT_DEFAULT  << PCIE_LC_CNTL__LC_L1_INACTIVITY__SHIFT;
+		else
+			data |= NAVI10_PCIE__LC_L1_INACTIVITY_DEFAULT << PCIE_LC_CNTL__LC_L1_INACTIVITY__SHIFT;
+
+		data &= ~PCIE_LC_CNTL__LC_PMI_TO_L1_DIS_MASK;
+	} else {
+		/* Disbale ASPM L1 */
+		data &= ~PCIE_LC_CNTL__LC_L1_INACTIVITY_MASK;
+		/* Disable ASPM TxL0s */
+		data &= ~PCIE_LC_CNTL__LC_L0S_INACTIVITY_MASK;
+		/* Disable ACPI L1 */
+		data |= PCIE_LC_CNTL__LC_PMI_TO_L1_DIS_MASK;
+	}
+
+	if (def != data)
+		WREG32_PCIE(smnPCIE_LC_CNTL, data);
+}
+
 const struct amdgpu_nbio_funcs nbio_v2_3_funcs = {
 	.get_hdp_flush_req_offset = nbio_v2_3_get_hdp_flush_req_offset,
 	.get_hdp_flush_done_offset = nbio_v2_3_get_hdp_flush_done_offset,
@@ -332,4 +370,5 @@ const struct amdgpu_nbio_funcs nbio_v2_3_funcs = {
 	.ih_control = nbio_v2_3_ih_control,
 	.init_registers = nbio_v2_3_init_registers,
 	.remap_hdp_registers = nbio_v2_3_remap_hdp_registers,
+	.enable_aspm = nbio_v2_3_enable_aspm,
 };