drm/amdkfd: report xgmi bandwidth between direct peers to the kfd

Report the min/max bandwidth in megabytes to the kfd for direct
xgmi connections only. Indirect peers will report 0 since
indirect route is unknown.

Signed-off-by: Jonathan Kim <[e-mail]>
Reviewed-by: Felix Kuehling <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 	return  (uint8_t)ret;
 }
 
+int amdgpu_amdkfd_get_xgmi_bandwidth_mbytes(struct kgd_dev *dst, struct kgd_dev *src, bool is_min)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)dst, *peer_adev;
+	int num_links;
+
+	if (adev->asic_type != CHIP_ALDEBARAN)
+		return 0;
+
+	if (src)
+		peer_adev = (struct amdgpu_device *)src;
+
+	/* num links returns 0 for indirect peers since indirect route is unknown. */
+	num_links = is_min ? 1 : amdgpu_xgmi_get_num_links(adev, peer_adev);
+	if (num_links < 0) {
+		DRM_ERROR("amdgpu: failed to get xgmi num links between node %d and %d. ret = %d\n",
+			adev->gmc.xgmi.physical_node_id,
+			peer_adev->gmc.xgmi.physical_node_id, num_links);
+		num_links = 0;
+	}
+
+	/* Aldebaran xGMI DPM is defeatured so assume x16 x 25Gbps for bandwidth. */
+	return (num_links * 16 * 25000)/BITS_PER_BYTE;
+}
+
 uint64_t amdgpu_amdkfd_get_mmio_remap_phys_addr(struct kgd_dev *kgd)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)kgd;

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

···
 uint32_t amdgpu_amdkfd_get_asic_rev_id(struct kgd_dev *kgd);
 int amdgpu_amdkfd_get_noretry(struct kgd_dev *kgd);
 uint8_t amdgpu_amdkfd_get_xgmi_hops_count(struct kgd_dev *dst, struct kgd_dev *src);
+int amdgpu_amdkfd_get_xgmi_bandwidth_mbytes(struct kgd_dev *dst, struct kgd_dev *src, bool is_min);
 
 /* Read user wptr from a specified user address space with page fault
  * disabled. The memory must be pinned and mapped to the hardware when

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

···
 	return	-EINVAL;
 }
 
+int amdgpu_xgmi_get_num_links(struct amdgpu_device *adev,
+		struct amdgpu_device *peer_adev)
+{
+	struct psp_xgmi_topology_info *top = &adev->psp.xgmi_context.top_info;
+	int i;
+
+	for (i = 0 ; i < top->num_nodes; ++i)
+		if (top->nodes[i].node_id == peer_adev->gmc.xgmi.node_id)
+			return top->nodes[i].num_links;
+	return	-EINVAL;
+}
+
 int amdgpu_xgmi_add_device(struct amdgpu_device *adev)
 {
 	struct psp_xgmi_topology_info *top_info;

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

···
 int amdgpu_xgmi_set_pstate(struct amdgpu_device *adev, int pstate);
 int amdgpu_xgmi_get_hops_count(struct amdgpu_device *adev,
 		struct amdgpu_device *peer_adev);
+int amdgpu_xgmi_get_num_links(struct amdgpu_device *adev,
+		struct amdgpu_device *peer_adev);
 uint64_t amdgpu_xgmi_get_relative_phy_addr(struct amdgpu_device *adev,
 					   uint64_t addr);
 static inline bool amdgpu_xgmi_same_hive(struct amdgpu_device *adev,

drivers/gpu/drm/amd/amdkfd/kfd_crat.c

···
 		sub_type_hdr->flags |= CRAT_IOLINK_FLAGS_BI_DIRECTIONAL;
 		sub_type_hdr->io_interface_type = CRAT_IOLINK_TYPE_XGMI;
 		sub_type_hdr->num_hops_xgmi = 1;
+		if (adev->asic_type == CHIP_ALDEBARAN) {
+			sub_type_hdr->minimum_bandwidth_mbs =
+					amdgpu_amdkfd_get_xgmi_bandwidth_mbytes(
+							kdev->kgd, NULL, true);
+			sub_type_hdr->maximum_bandwidth_mbs =
+					sub_type_hdr->minimum_bandwidth_mbs;
+		}
 	} else {
 		sub_type_hdr->io_interface_type = CRAT_IOLINK_TYPE_PCIEXPRESS;
 	}
···
 	sub_type_hdr->proximity_domain_to = proximity_domain_to;
 	sub_type_hdr->num_hops_xgmi =
 		amdgpu_amdkfd_get_xgmi_hops_count(kdev->kgd, peer_kdev->kgd);
+	sub_type_hdr->maximum_bandwidth_mbs =
+		amdgpu_amdkfd_get_xgmi_bandwidth_mbytes(kdev->kgd, peer_kdev->kgd, false);
+	sub_type_hdr->minimum_bandwidth_mbs = sub_type_hdr->maximum_bandwidth_mbs ?
+		amdgpu_amdkfd_get_xgmi_bandwidth_mbytes(kdev->kgd, NULL, true) : 0;
+
 	return 0;
 }