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authorNayna Jain <nayna@linux.vnet.ibm.com>2017-01-23 10:26:26 +0300
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2017-02-03 23:03:14 +0300
commite46e22f12b19f0068b02afcf6edb716b4f49934f (patch)
treee56538bada035a1d05b6ca606f3ea07184b314b8 /drivers/char
parentc1f92b4b04ad7006bdcbd1d5bb63f2864b06b7f8 (diff)
downloadlinux-e46e22f12b19f0068b02afcf6edb716b4f49934f.tar.xz
tpm: enhance read_log_of() to support Physical TPM event log
Physical TPMs use Open Firmware Device Tree bindings that are similar to the IBM Power virtual TPM to support event log. However, these properties store the values in different endianness for Physical and Virtual TPM. This patch fixes the endianness issue by doing appropriate conversion based on Physical or Virtual TPM. Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Kenneth Goldman <kgold@linux.vnet.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_of.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index 7dee42d7b5e0..de57d4ac8901 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -27,6 +27,8 @@ int tpm_read_log_of(struct tpm_chip *chip)
const u32 *sizep;
const u64 *basep;
struct tpm_bios_log *log;
+ u32 size;
+ u64 base;
log = &chip->log;
if (chip->dev.parent && chip->dev.parent->of_node)
@@ -41,18 +43,35 @@ int tpm_read_log_of(struct tpm_chip *chip)
if (sizep == NULL || basep == NULL)
return -EIO;
- if (*sizep == 0) {
+ /*
+ * For both vtpm/tpm, firmware has log addr and log size in big
+ * endian format. But in case of vtpm, there is a method called
+ * sml-handover which is run during kernel init even before
+ * device tree is setup. This sml-handover function takes care
+ * of endianness and writes to sml-base and sml-size in little
+ * endian format. For this reason, vtpm doesn't need conversion
+ * but physical tpm needs the conversion.
+ */
+ if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
+ size = be32_to_cpup(sizep);
+ base = be64_to_cpup(basep);
+ } else {
+ size = *sizep;
+ base = *basep;
+ }
+
+ if (size == 0) {
dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
return -EIO;
}
- log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
+ log->bios_event_log = kmalloc(size, GFP_KERNEL);
if (!log->bios_event_log)
return -ENOMEM;
- log->bios_event_log_end = log->bios_event_log + *sizep;
+ log->bios_event_log_end = log->bios_event_log + size;
- memcpy(log->bios_event_log, __va(*basep), *sizep);
+ memcpy(log->bios_event_log, __va(base), size);
return 0;
}