[PATCH 1/4] firmware: dmi: Remember the memory type

Jean Delvare
2019-11-18T09:25:46Z

Store the memory type while walking the memory slots, and provide a
way to retrieve it later.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
---
drivers/firmware/dmi_scan.c | 25 ++++++++++++++++++++++++-
include/linux/dmi.h | 2 ++
2 files changed, 26 insertions(+), 1 deletion(-)

--- linux-5.3.orig/drivers/firmware/dmi_scan.c 2019-10-08 14:27:23.783640227 +0200
+++ linux-5.3/drivers/firmware/dmi_scan.c 2019-10-08 16:35:35.442803880 +0200
@@ -35,6 +35,7 @@ static struct dmi_memdev_info {
const char *bank;
u64 size; /* bytes */
u16 handle;
+ u8 type; /* DDR2, DDR3, DDR4 etc */
} *dmi_memdev;
static int dmi_memdev_nr;

@@ -391,7 +392,7 @@ static void __init save_mem_devices(cons
u64 bytes;
u16 size;

- if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x12)
+ if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x13)
return;
if (nr >= dmi_memdev_nr) {
pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
@@ -400,6 +401,7 @@ static void __init save_mem_devices(cons
dmi_memdev[nr].handle = get_unaligned(&dm->handle);
dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
+ dmi_memdev[nr].type = d[0x12];

size = get_unaligned((u16 *)&d[0xC]);
if (size == 0)
@@ -1128,3 +1130,24 @@ u64 dmi_memdev_size(u16 handle)
return ~0ull;
}
EXPORT_SYMBOL_GPL(dmi_memdev_size);
+
+/**
+ * dmi_memdev_type - get the memory type
+ * @handle: DMI structure handle
+ *
+ * Return the DMI memory type of the module in the slot associated with the
+ * given DMI handle, or 0x0 if no such DMI handle exists.
+ */
+u8 dmi_memdev_type(u16 handle)
+{
+ int n;
+
+ if (dmi_memdev) {
+ for (n = 0; n < dmi_memdev_nr; n++) {
+ if (handle == dmi_memdev[n].handle)
+ return dmi_memdev[n].type;
+ }
+ }
+ return 0x0; /* Not a valid value */
+}
+EXPORT_SYMBOL_GPL(dmi_memdev_type);
--- linux-5.3.orig/include/linux/dmi.h 2019-10-04 16:14:24.575714482 +0200
+++ linux-5.3/include/linux/dmi.h 2019-10-08 17:42:19.726907967 +0200
@@ -113,6 +113,7 @@ extern int dmi_walk(void (*decode)(const
extern bool dmi_match(enum dmi_field f, const char *str);
extern void dmi_memdev_name(u16 handle, const char **bank, const char **device);
extern u64 dmi_memdev_size(u16 handle);
+extern u8 dmi_memdev_type(u16 handle);

#else

@@ -142,6 +143,7 @@ static inline bool dmi_match(enum dmi_fi
static inline void dmi_memdev_name(u16 handle, const char **bank,
const char **device) { }
static inline u64 dmi_memdev_size(u16 handle) { return ~0ul; }
+static inline u8 dmi_memdev_type(u16 handle) { return 0x0; }
static inline const struct dmi_system_id *
dmi_first_match(const struct dmi_system_id *list) { return NULL; }