The TPM will respond to TPM_GET_CAP with TPM_ERR_INVALID_POSTINIT if
TPM_STARTUP has not been issued. Detect this and automatically
issue TPM_STARTUP.
This is for embedded applications where the kernel is the first thing
to touch the TPM.
Signed-off-by: Jason Gunthorpe <jguntho...@obsidianresearch.com>
---
drivers/char/tpm/tpm.c | 43 +++++++++++++++++++++++++++++++++++++++----
drivers/char/tpm/tpm.h | 6 ++++++
2 files changed, 45 insertions(+), 4 deletions(-)
changes in v2:
- Created a tpm_startup function as per Kent's comment
- Fixed the TPM_ST_* constants to be 16 bit
- Provide ST_STATE and ST_DEACTIVATED constants for future users
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 817f0ee..5d79093 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -473,7 +473,7 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct
tpm_cmd_t *cmd,
return -EFAULT;
err = be32_to_cpu(cmd->header.out.return_code);
- if (err != 0)
+ if (err != 0 && desc)
dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
return err;
@@ -489,6 +489,16 @@ static const struct tpm_input_header tpm_getcap_header = {
.ordinal = TPM_ORD_GET_CAP
};
+#define TPM_ORD_STARTUP cpu_to_be32(153)
+#define TPM_ST_CLEAR cpu_to_be16(1)
+#define TPM_ST_STATE cpu_to_be16(2)
+#define TPM_ST_DEACTIVATED cpu_to_be16(3)
+static const struct tpm_input_header tpm_startup_header = {
+ .tag = TPM_TAG_RQU_COMMAND,
+ .length = cpu_to_be32(12),
+ .ordinal = TPM_ORD_STARTUP
+};
+
ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
const char *desc)
{
@@ -532,6 +542,15 @@ void tpm_gen_interrupt(struct tpm_chip *chip)
}
EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
+static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
+{
+ struct tpm_cmd_t start_cmd;
+ start_cmd.header.in = tpm_startup_header;
+ start_cmd.params.startup_in.startup_type = startup_type;
+ return transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
+ "attempting to start the TPM");
+}
+
int tpm_get_timeouts(struct tpm_chip *chip)
{
struct tpm_cmd_t tpm_cmd;
@@ -545,11 +564,27 @@ int tpm_get_timeouts(struct tpm_chip *chip)
tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
+ rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0);
- rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
- "attempting to determine the timeouts");
- if (rc)
+ if (rc == TPM_ERR_INVALID_POSTINIT) {
+ /* The TPM is not started, we are the first to talk to it.
+ Execute a startup command. */
+ dev_info(chip->dev, "Issuing TPM_STARTUP");
+ if (tpm_startup(chip, TPM_ST_CLEAR))
+ return rc;
+
+ tpm_cmd.header.in = tpm_getcap_header;
+ tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
+ tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
+ tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
+ rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0);
+ }
+ if (rc) {
+ dev_err(chip->dev,
+ "A TPM error (%d) occurred attempting to determine the
timeouts\n",
+ rc);
goto duration;
+ }
if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
be32_to_cpu(tpm_cmd.header.out.length)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 917f727..2d583ef 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -41,6 +41,7 @@ enum tpm_addr {
#define TPM_WARN_DOING_SELFTEST 0x802
#define TPM_ERR_DEACTIVATED 0x6
#define TPM_ERR_DISABLED 0x7
+#define TPM_ERR_INVALID_POSTINIT 38
#define TPM_HEADER_SIZE 10
extern ssize_t tpm_show_pubek(struct device *, struct device_attribute *attr,
@@ -269,6 +270,10 @@ struct tpm_pcrextend_in {
u8 hash[TPM_DIGEST_SIZE];
}__attribute__((packed));
+struct tpm_startup_in {
+ __be16 startup_type;
+} __packed;
+
typedef union {
struct tpm_getcap_params_out getcap_out;
struct tpm_readpubek_params_out readpubek_out;
@@ -277,6 +282,7 @@ typedef union {
struct tpm_pcrread_in pcrread_in;
struct tpm_pcrread_out pcrread_out;
struct tpm_pcrextend_in pcrextend_in;
+ struct tpm_startup_in startup_in;
} tpm_cmd_params;
struct tpm_cmd_t {
--
1.7.4.1
--
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