drm/amdkfd: Allow building KFD on ARM64 (v2)

ifdef x86_64 specific code.
Allow enabling CONFIG_HSA_AMD on ARM64.

v2: Fixed a compiler warning due to an unused variable

CC: Mark Nutter <Mark.Nutter@arm.com>
Signed-off-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Tested-by: NMark Nutter <Mark.Nutter@arm.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/Kconfig

@@ -4,8 +4,8 @@
 
 config HSA_AMD
 	bool "HSA kernel driver for AMD GPU devices"
-	depends on DRM_AMDGPU && X86_64
-	imply AMD_IOMMU_V2
+	depends on DRM_AMDGPU && (X86_64 || ARM64)
+	imply AMD_IOMMU_V2 if X86_64
 	select MMU_NOTIFIER
 	help
 	  Enable this if you want to use HSA features on AMD GPU devices.

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

@@ -863,6 +863,7 @@ static int kfd_fill_mem_info_for_cpu(int numa_node_id, int *avail_size,
 	return 0;
 }
 
+#if CONFIG_X86_64
 static int kfd_fill_iolink_info_for_cpu(int numa_node_id, int *avail_size,
 				uint32_t *num_entries,
 				struct crat_subtype_iolink *sub_type_hdr)
@@ -905,6 +906,7 @@ static int kfd_fill_iolink_info_for_cpu(int numa_node_id, int *avail_size,
 
 	return 0;
 }
+#endif
 
 /* kfd_create_vcrat_image_cpu - Create Virtual CRAT for CPU
  *
@@ -920,7 +922,9 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
 	struct crat_subtype_generic *sub_type_hdr;
 	int avail_size = *size;
 	int numa_node_id;
+#ifdef CONFIG_X86_64
 	uint32_t entries = 0;
+#endif
 	int ret = 0;
 
 	if (!pcrat_image || avail_size < VCRAT_SIZE_FOR_CPU)
@@ -982,6 +986,7 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
 			sub_type_hdr->length);
 
 		/* Fill in Subtype: IO Link */
+#ifdef CONFIG_X86_64
 		ret = kfd_fill_iolink_info_for_cpu(numa_node_id, &avail_size,
 				&entries,
 				(struct crat_subtype_iolink *)sub_type_hdr);
@@ -992,6 +997,9 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
 
 		sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr +
 				sub_type_hdr->length * entries);
+#else
+		pr_info("IO link not available for non x86 platforms\n");
+#endif
 
 		crat_table->num_domains++;
 	}

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

@@ -1392,7 +1392,6 @@ int kfd_topology_enum_kfd_devices(uint8_t idx, struct kfd_dev **kdev)
 
 static int kfd_cpumask_to_apic_id(const struct cpumask *cpumask)
 {
-	const struct cpuinfo_x86 *cpuinfo;
 	int first_cpu_of_numa_node;
 
 	if (!cpumask || cpumask == cpu_none_mask)
@@ -1400,9 +1399,11 @@ static int kfd_cpumask_to_apic_id(const struct cpumask *cpumask)
 	first_cpu_of_numa_node = cpumask_first(cpumask);
 	if (first_cpu_of_numa_node >= nr_cpu_ids)
 		return -1;
-	cpuinfo = &cpu_data(first_cpu_of_numa_node);
-
-	return cpuinfo->apicid;
+#ifdef CONFIG_X86_64
+	return cpu_data(first_cpu_of_numa_node).apicid;
+#else
+	return first_cpu_of_numa_node;
+#endif
 }
 
 /* kfd_numa_node_to_apic_id - Returns the APIC ID of the first logical processor