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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2014-10-14 16:41:27 +0200
committerKees Cook <keescook@google.com>2015-10-07 13:12:50 -0700
commit9390abcdbc7cb720109a63e7157d3561b22631bf (patch)
tree8b83bfd9b88d3921ec09e1bd246423af802d1695
parentcb7c0454c3cb6ad7f86a0c6546ba9cfb963a7888 (diff)
downloadlinux-linaro-stable-9390abcdbc7cb720109a63e7157d3561b22631bf.tar.gz
UPSTREAM: dmi: add support for SMBIOS 3.0 64-bit entry point
The DMTF SMBIOS reference spec v3.0.0 defines a new 64-bit entry point, which enables support for SMBIOS structure tables residing at a physical offset over 4 GB. This is especially important for upcoming arm64 platforms whose system RAM resides entirely above the 4 GB boundary. For the UEFI case, this code attempts to detect the new SMBIOS 3.0 header magic at the offset passed in the SMBIOS3_TABLE_GUID UEFI configuration table. If this configuration table is not provided, or if we fail to parse the header, we fall back to using the legacy SMBIOS_TABLE_GUID configuration table. This is in line with the spec, that allows both configuration tables to be provided, but mandates that they must point to the same structure table, unless the version pointed to by the 64-bit entry point is a superset of the 32-bit one. For the non-UEFI case, the detection logic is modified to look for the SMBIOS 3.0 header magic before it looks for the legacy header magic. Note that this patch is based on version 3.0.0d [draft] of the specification, which is expected not to deviate from the final version in ways that would affect the correctness of this implementation. Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tony Luck <tony.luck@intel.com> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> (cherry picked from commit fc43026278b23b3515cf8f909ec29df94b3ae1a2) Signed-off-by: Tomasz Figa <tfiga@chromium.org> Bug: 24475017 Change-Id: I02fae4d34964865455129f67ecc81754de9b3987 Signed-off-by: Kees Cook <keescook@google.com>
-rw-r--r--drivers/firmware/dmi_scan.c79
1 files changed, 72 insertions, 7 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 17afc51f3054..c5f7b4e9eb6c 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -93,6 +93,12 @@ static void dmi_table(u8 *buf, int len, int num,
const struct dmi_header *dm = (const struct dmi_header *)data;
/*
+ * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
+ */
+ if (dm->type == DMI_ENTRY_END_OF_TABLE)
+ break;
+
+ /*
* We want to know the total length (formatted area and
* strings) before decoding to make sure we won't run off the
* table in dmi_decode or dmi_string
@@ -107,7 +113,7 @@ static void dmi_table(u8 *buf, int len, int num,
}
}
-static u32 dmi_base;
+static phys_addr_t dmi_base;
static u16 dmi_len;
static u16 dmi_num;
@@ -467,7 +473,7 @@ static int __init dmi_present(const u8 *buf)
if (memcmp(buf, "_SM_", 4) == 0 &&
buf[5] < 32 && dmi_checksum(buf, buf[5])) {
- smbios_ver = (buf[6] << 8) + buf[7];
+ smbios_ver = get_unaligned_be16(buf + 6);
/* Some BIOS report weird SMBIOS version, fix that up */
switch (smbios_ver) {
@@ -489,10 +495,9 @@ static int __init dmi_present(const u8 *buf)
buf += 16;
if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {
- dmi_num = (buf[13] << 8) | buf[12];
- dmi_len = (buf[7] << 8) | buf[6];
- dmi_base = (buf[11] << 24) | (buf[10] << 16) |
- (buf[9] << 8) | buf[8];
+ dmi_num = get_unaligned_le16(buf + 12);
+ dmi_len = get_unaligned_le16(buf + 6);
+ dmi_base = get_unaligned_le32(buf + 8);
if (dmi_walk_early(dmi_decode) == 0) {
if (smbios_ver) {
@@ -514,12 +519,72 @@ static int __init dmi_present(const u8 *buf)
return 1;
}
+/*
+ * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
+ * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
+ */
+static int __init dmi_smbios3_present(const u8 *buf)
+{
+ if (memcmp(buf, "_SM3_", 5) == 0 &&
+ buf[6] < 32 && dmi_checksum(buf, buf[6])) {
+ dmi_ver = get_unaligned_be16(buf + 7);
+ dmi_len = get_unaligned_le32(buf + 12);
+ dmi_base = get_unaligned_le64(buf + 16);
+
+ /*
+ * The 64-bit SMBIOS 3.0 entry point no longer has a field
+ * containing the number of structures present in the table.
+ * Instead, it defines the table size as a maximum size, and
+ * relies on the end-of-table structure type (#127) to be used
+ * to signal the end of the table.
+ * So let's define dmi_num as an upper bound as well: each
+ * structure has a 4 byte header, so dmi_len / 4 is an upper
+ * bound for the number of structures in the table.
+ */
+ dmi_num = dmi_len / 4;
+
+ if (dmi_walk_early(dmi_decode) == 0) {
+ pr_info("SMBIOS %d.%d present.\n",
+ dmi_ver >> 8, dmi_ver & 0xFF);
+ dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
+ pr_debug("DMI: %s\n", dmi_ids_string);
+ return 0;
+ }
+ }
+ return 1;
+}
+
void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
char buf[32];
if (efi_enabled(EFI_CONFIG_TABLES)) {
+ /*
+ * According to the DMTF SMBIOS reference spec v3.0.0, it is
+ * allowed to define both the 64-bit entry point (smbios3) and
+ * the 32-bit entry point (smbios), in which case they should
+ * either both point to the same SMBIOS structure table, or the
+ * table pointed to by the 64-bit entry point should contain a
+ * superset of the table contents pointed to by the 32-bit entry
+ * point (section 5.2)
+ * This implies that the 64-bit entry point should have
+ * precedence if it is defined and supported by the OS. If we
+ * have the 64-bit entry point, but fail to decode it, fall
+ * back to the legacy one (if available)
+ */
+ if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
+ p = dmi_early_remap(efi.smbios3, 32);
+ if (p == NULL)
+ goto error;
+ memcpy_fromio(buf, p, 32);
+ dmi_early_unmap(p, 32);
+
+ if (!dmi_smbios3_present(buf)) {
+ dmi_available = 1;
+ goto out;
+ }
+ }
if (efi.smbios == EFI_INVALID_TABLE_ADDR)
goto error;
@@ -552,7 +617,7 @@ void __init dmi_scan_machine(void)
memset(buf, 0, 16);
for (q = p; q < p + 0x10000; q += 16) {
memcpy_fromio(buf + 16, q, 16);
- if (!dmi_present(buf)) {
+ if (!dmi_smbios3_present(buf) || !dmi_present(buf)) {
dmi_available = 1;
dmi_early_unmap(p, 0x10000);
goto out;