There are situations when code needs to access SMBIOS entry table area. For example, to pass it via sysfs to userspace when it's not allowed to get SMBIOS info via /dev/mem.
Signed-off-by: Ivan Khoronzhuk ivan.khoronzhuk@linaro.org --- drivers/firmware/dmi_scan.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/dmi.h | 2 ++ 2 files changed, 36 insertions(+)
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 420c8d8..ae9204a 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -113,6 +113,7 @@ static void dmi_table(u8 *buf, int len, int num, } }
+static unsigned char smbios_header[32]; static phys_addr_t dmi_base; static u16 dmi_len; static u16 dmi_num; @@ -474,6 +475,7 @@ static int __init dmi_present(const u8 *buf) if (memcmp(buf, "_SM_", 4) == 0 && buf[5] < 32 && dmi_checksum(buf, buf[5])) { smbios_ver = get_unaligned_be16(buf + 6); + memcpy(smbios_header, buf, buf[5]);
/* Some BIOS report weird SMBIOS version, fix that up */ switch (smbios_ver) { @@ -505,6 +507,7 @@ static int __init dmi_present(const u8 *buf) pr_info("SMBIOS %d.%d present.\n", dmi_ver >> 8, dmi_ver & 0xFF); } else { + memcpy(smbios_header, buf, 15); dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F); pr_info("Legacy DMI %d.%d present.\n", @@ -531,6 +534,7 @@ static int __init dmi_smbios3_present(const u8 *buf) dmi_ver &= 0xFFFFFF; dmi_len = get_unaligned_le32(buf + 12); dmi_base = get_unaligned_le64(buf + 16); + memcpy(smbios_header, buf, buf[6]);
/* * The 64-bit SMBIOS 3.0 entry point no longer has a field @@ -944,3 +948,33 @@ void dmi_memdev_name(u16 handle, const char **bank, const char **device) } } EXPORT_SYMBOL_GPL(dmi_memdev_name); + +/** + * dmi_get_smbios_entry_area - copy SMBIOS entry point area to array. + * @entry - pointer on array to read area in, current max size is 32 bytes. + * + * returns -ENODATA if table is not available, otherwise returns actual + * size of SMBIOS entry point area. + */ +int dmi_get_smbios_entry_area(char *table) +{ + int size = 0; + + if (!dmi_available) + return -ENODATA; + + if (memcmp(smbios_header, "_SM3_", 5) == 0) + size = smbios_header[6]; + else if (memcmp(smbios_header, "_SM_", 4) == 0) + size = smbios_header[5]; + else if (memcmp(smbios_header, "_DMI_", 5) == 0) + size = 15; + + memcpy(table, smbios_header, size); + + if (!size) + return -ENODATA; + + return size; +} +EXPORT_SYMBOL_GPL(dmi_get_smbios_entry_area); diff --git a/include/linux/dmi.h b/include/linux/dmi.h index f820f0a..4b7f2a3 100644 --- a/include/linux/dmi.h +++ b/include/linux/dmi.h @@ -109,6 +109,7 @@ extern int dmi_walk(void (*decode)(const struct dmi_header *, void *), void *private_data); extern bool dmi_match(enum dmi_field f, const char *str); extern void dmi_memdev_name(u16 handle, const char **bank, const char **device); +int dmi_get_smbios_entry_area(char *table);
#else
@@ -140,6 +141,7 @@ static inline void dmi_memdev_name(u16 handle, const char **bank, const char **device) { } static inline const struct dmi_system_id * dmi_first_match(const struct dmi_system_id *list) { return NULL; } +static int dmi_get_smbios_entry_area(char *table) { return -ENODATA; }
#endif