drm/amd: Refactor find_system_memory()

find_system_memory() pulls out two fields from an SMBIOS type 17
device and sets them on KFD devices. The data offsets are counted
to find interesting data.

Instead use a struct representation to access the members and pull
out the two specific fields.

No intended functional changes.

Link: https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.8.0.pdf
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Link: https://lore.kernel.org/r/20250206214847.3334595-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index 4936697e6fc2b6fc2a5904188be5fef12a5598b2..28516ae968327ede8a99f0bc461547faef3be6e7 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -950,24 +950,23 @@ static void kfd_update_system_properties(void)
        up_read(&topology_lock);
 }
 
-static void find_system_memory(const struct dmi_header *dm,
-       void *private)
+static void find_system_memory(const struct dmi_header *dm, void *private)
 {
+       struct dmi_mem_device *memdev = container_of(dm, struct dmi_mem_device, header);
        struct kfd_mem_properties *mem;
-       u16 mem_width, mem_clock;
        struct kfd_topology_device *kdev =
                (struct kfd_topology_device *)private;
-       const u8 *dmi_data = (const u8 *)(dm + 1);
-
-       if (dm->type == DMI_ENTRY_MEM_DEVICE && dm->length >= 0x15) {
-               mem_width = (u16)(*(const u16 *)(dmi_data + 0x6));
-               mem_clock = (u16)(*(const u16 *)(dmi_data + 0x11));
-               list_for_each_entry(mem, &kdev->mem_props, list) {
-                       if (mem_width != 0xFFFF && mem_width != 0)
-                               mem->width = mem_width;
-                       if (mem_clock != 0)
-                               mem->mem_clk_max = mem_clock;
-               }
+
+       if (memdev->header.type != DMI_ENTRY_MEM_DEVICE)
+               return;
+       if (memdev->header.length < sizeof(struct dmi_mem_device))
+               return;
+
+       list_for_each_entry(mem, &kdev->mem_props, list) {
+               if (memdev->total_width != 0xFFFF && memdev->total_width != 0)
+                       mem->width = memdev->total_width;
+               if (memdev->speed != 0)
+                       mem->mem_clk_max = memdev->speed;
        }
 }
 

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.h b/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
index 155b5c410af1651ae245fdb0aa2ce8ac33a5edf5..f06c9db7ddde92366906707fe869f10ea8a463f3 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
@@ -24,6 +24,7 @@
 #ifndef __KFD_TOPOLOGY_H__
 #define __KFD_TOPOLOGY_H__
 
+#include <linux/dmi.h>
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/kfd_sysfs.h>
@@ -179,6 +180,22 @@ struct kfd_system_properties {
        struct attribute        attr_props;
 };
 
+struct dmi_mem_device {
+       struct dmi_header header;
+       u16 physical_handle;
+       u16 error_handle;
+       u16 total_width;
+       u16 data_width;
+       u16 size;
+       u8 form_factor;
+       u8 device_set;
+       u8 device_locator;
+       u8 bank_locator;
+       u8 memory_type;
+       u16 type_detail;
+       u16 speed;
+} __packed;
+
 struct kfd_topology_device *kfd_create_topology_device(
                struct list_head *device_list);
 void kfd_release_topology_device_list(struct list_head *device_list);