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Subject[PATCH v3 08/20] tpm: factor out tpm1_get_random into tpm1-cmd.c
Date
Factor out get random implementation from tpm-interface.c
into tpm1_get_random function in tpm1-cmd.c.
No functional changes.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
V2-V3: Rebase

drivers/char/tpm/tpm-interface.c | 58 +++++-----------------------------------
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm1-cmd.c | 55 +++++++++++++++++++++++++++++++++++++
3 files changed, 63 insertions(+), 51 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 59ca0cdda811..c15957fef08f 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -801,14 +801,6 @@ int tpm_pm_resume(struct device *dev)
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);

-#define TPM_ORD_GET_RANDOM 70
-#define TPM_GETRANDOM_RESULT_SIZE 18
-static const struct tpm_input_header tpm_getrandom_header = {
- .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
- .length = cpu_to_be32(14),
- .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
-};
-
/**
* tpm_get_random() - get random bytes from the TPM's RNG
* @chip: a &struct tpm_chip instance, %NULL for the default chip
@@ -819,58 +811,22 @@ static const struct tpm_input_header tpm_getrandom_header = {
*/
int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
- struct tpm_cmd_t tpm_cmd;
- u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
- int err, total = 0, retries = 5;
- u8 *dest = out;
+ int rc;

- if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+ if (!out || max > TPM_MAX_RNG_DATA)
return -EINVAL;

chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;

- if (chip->flags & TPM_CHIP_FLAG_TPM2) {
- err = tpm2_get_random(chip, out, max);
- tpm_put_ops(chip);
- return err;
- }
-
- do {
- tpm_cmd.header.in = tpm_getrandom_header;
- tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
-
- err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
- TPM_GETRANDOM_RESULT_SIZE + num_bytes,
- offsetof(struct tpm_getrandom_out,
- rng_data),
- 0, "attempting get random");
- if (err)
- break;
-
- recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
- if (recd > num_bytes) {
- total = -EFAULT;
- break;
- }
-
- rlength = be32_to_cpu(tpm_cmd.header.out.length);
- if (rlength < TPM_HEADER_SIZE +
- offsetof(struct tpm_getrandom_out, rng_data) +
- recd) {
- total = -EFAULT;
- break;
- }
- memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
-
- dest += recd;
- total += recd;
- num_bytes -= recd;
- } while (retries-- && total < max);
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_get_random(chip, out, max);
+ else
+ rc = tpm1_get_random(chip, out, max);

tpm_put_ops(chip);
- return total ? total : -EIO;
+ return rc;
}
EXPORT_SYMBOL_GPL(tpm_get_random);

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 1c1980c79c30..496a56156e77 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -551,6 +551,7 @@ int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
const char *log_msg);
ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
const char *desc, size_t min_cap_length);
+int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max);
unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);
int tpm_pm_suspend(struct device *dev);
int tpm_pm_resume(struct device *dev);
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index 8aa3e3cfed71..e7e0528e2e06 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -470,3 +470,58 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
return rc;
}
EXPORT_SYMBOL_GPL(tpm1_getcap);
+
+#define TPM_ORD_GET_RANDOM 70
+#define TPM_GETRANDOM_RESULT_SIZE 18
+static const struct tpm_input_header tpm_getrandom_header = {
+ .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
+ .length = cpu_to_be32(14),
+ .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
+};
+
+int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+ struct tpm_cmd_t tpm_cmd;
+ u32 recd;
+ u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
+ u32 rlength;
+ int err, total = 0, retries = 5;
+ u8 *dest = out;
+
+ if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+ return -EINVAL;
+
+ do {
+ tpm_cmd.header.in = tpm_getrandom_header;
+ tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
+
+ err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
+ TPM_GETRANDOM_RESULT_SIZE + num_bytes,
+ offsetof(struct tpm_getrandom_out,
+ rng_data),
+ 0, "attempting get random");
+ if (err)
+ break;
+
+ recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
+ if (recd > num_bytes) {
+ total = -EFAULT;
+ break;
+ }
+
+ rlength = be32_to_cpu(tpm_cmd.header.out.length);
+ if (rlength < TPM_HEADER_SIZE +
+ offsetof(struct tpm_getrandom_out, rng_data) +
+ recd) {
+ total = -EFAULT;
+ break;
+ }
+ memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
+
+ dest += recd;
+ total += recd;
+ num_bytes -= recd;
+ } while (retries-- && (size_t)total < max);
+
+ return total ? total : -EIO;
+}
--
2.14.4
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