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.khoronz...@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..7cae713 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 inline int dmi_get_smbios_entry_area(char *table) { return -ENODATA; }
#endif
--
1.9.1
--
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