The patch simply replaces all msleep function calls with usleep_range calls
in the generic drivers.
Tested with an Infineon TPM 1.2, using the generic tpm-tis module, for a
thousand PCR extends, we see results going from 1m57s unpatched to 40s
with the new patch. We obtain similar results when using the original and
patched tpm_infineon driver, which is also part of the patch.
Similarly with a STM TPM 2.0, using the CRB driver, it takes about 20ms per
extend unpatched and around 7ms with the new patch.
Note that the PCR consistency is untouched with this patch, each TPM has
been tested with 10 million extends and the aggregated PCR value is
continuously verified to be correct.
As an extension of this work, this could potentially and easily be applied
to other vendor's drivers. Still, these changes are not included in the
proposed patch as they are untested.
Signed-off-by: Hamza Attak <ha...@hpe.com>
---
drivers/char/tpm/tpm-interface.c | 18 +++++++++++-------
drivers/char/tpm/tpm.h | 11 +++++++++--
drivers/char/tpm/tpm2-cmd.c | 6 +++---
drivers/char/tpm/tpm_infineon.c | 17 ++++++++++-------
drivers/char/tpm/tpm_tis_core.c | 11 +++++++----
5 files changed, 40 insertions(+), 23 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index bd2128e..95276d1 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -395,7 +395,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf,
size_t bufsiz,
goto out;
}
- msleep(TPM_TIMEOUT); /* CHECK */
+ usleep_range(TPM_TIMEOUT_US,
+ TPM_TIMEOUT_US + TPM_TIMEOUT_RANGE_US);
rmb();
} while (time_before(jiffies, stop));
@@ -836,13 +837,13 @@ int tpm_do_selftest(struct tpm_chip *chip)
{
int rc;
unsigned int loops;
- unsigned int delay_msec = 100;
+ unsigned int delay_usec = 100000;
unsigned long duration;
u8 dummy[TPM_DIGEST_SIZE];
duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
- loops = jiffies_to_msecs(duration) / delay_msec;
+ loops = jiffies_to_usecs(duration) / delay_usec;
rc = tpm_continue_selftest(chip);
/* This may fail if there was no TPM driver during a suspend/resume
@@ -862,7 +863,8 @@ int tpm_do_selftest(struct tpm_chip *chip)
dev_info(
&chip->dev, HW_ERR
"TPM command timed out during continue self test");
- msleep(delay_msec);
+ usleep_range(delay_usec,
+ delay_usec + TPM_TIMEOUT_RANGE_US);
continue;
}
@@ -877,7 +879,7 @@ int tpm_do_selftest(struct tpm_chip *chip)
}
if (rc != TPM_WARN_DOING_SELFTEST)
return rc;
- msleep(delay_msec);
+ usleep_range(delay_usec, delay_usec + TPM_TIMEOUT_RANGE_US);
} while (--loops > 0);
return rc;
@@ -977,7 +979,8 @@ again:
}
} else {
do {
- msleep(TPM_TIMEOUT);
+ usleep_range(TPM_TIMEOUT_US,
+ TPM_TIMEOUT_US + TPM_TIMEOUT_RANGE_US);
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
@@ -1045,7 +1048,8 @@ int tpm_pm_suspend(struct device *dev)
*/
if (rc != TPM_WARN_RETRY)
break;
- msleep(TPM_TIMEOUT_RETRY);
+ usleep_range(TPM_TIMEOUT_RETRY_US,
+ TPM_TIMEOUT_RETRY_US + TPM_TIMEOUT_RANGE_US);
}
if (rc)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4937b56..c1ace6c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -45,8 +45,15 @@ enum tpm_const {
};
enum tpm_timeout {
- TPM_TIMEOUT = 5, /* msecs */
- TPM_TIMEOUT_RETRY = 100 /* msecs */
+ TPM_TIMEOUT = 5, /* msecs */
+ TPM_TIMEOUT_RETRY = 100, /* msecs */
+ /* Ideally all the drivers should be using the usecs values,
+ * the msecs values are only kept there for compatibility purposes
+ * with the remaining untested drivers.
+ */
+ TPM_TIMEOUT_US = TPM_TIMEOUT * 1000, /* usecs */
+ TPM_TIMEOUT_RETRY_US = TPM_TIMEOUT_RETRY * 1000, /* usecs */
+ TPM_TIMEOUT_RANGE_US = 300 /* usecs */
};
/* TPM addresses */
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 881aea9..425caa4 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -930,14 +930,14 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
{
int rc;
unsigned int loops;
- unsigned int delay_msec = 100;
+ unsigned int delay_usec = 100000;
unsigned long duration;
struct tpm2_cmd cmd;
int i;
duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
- loops = jiffies_to_msecs(duration) / delay_msec;
+ loops = jiffies_to_usecs(duration) / delay_usec;
rc = tpm2_start_selftest(chip, true);
if (rc)
@@ -961,7 +961,7 @@ static int tpm2_do_selftest(struct tpm_chip *chip)
if (rc != TPM2_RC_TESTING)
break;
- msleep(delay_msec);
+ usleep_range(delay_usec, delay_usec + TPM_TIMEOUT_RANGE_US);
}
return rc;
diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
index e3cf9f3..c9d2d13 100644
--- a/drivers/char/tpm/tpm_infineon.c
+++ b/drivers/char/tpm/tpm_infineon.c
@@ -22,10 +22,10 @@
/* Infineon specific definitions */
/* maximum number of WTX-packages */
#define TPM_MAX_WTX_PACKAGES 50
-/* msleep-Time for WTX-packages */
-#define TPM_WTX_MSLEEP_TIME 20
-/* msleep-Time --> Interval to check status register */
-#define TPM_MSLEEP_TIME 3
+/* usleep-Time for WTX-packages */
+#define TPM_WTX_USLEEP_TIME (20 * 1000)
+/* usleep-Time --> Interval to check status register */
+#define TPM_USLEEP_TIME (3 * 1000)
/* gives number of max. msleep()-calls before throwing timeout */
#define TPM_MAX_TRIES 5000
#define TPM_INFINEON_DEV_VEN_VALUE 0x15D1
@@ -191,7 +191,8 @@ static int wait(struct tpm_chip *chip, int wait_for_bit)
/* check the status-register if wait_for_bit is set */
if (status & 1 << wait_for_bit)
break;
- msleep(TPM_MSLEEP_TIME);
+ usleep_range(TPM_USLEEP_TIME,
+ TPM_USLEEP_TIME + TPM_TIMEOUT_RANGE_US);
}
if (i == TPM_MAX_TRIES) { /* timeout occurs */
if (wait_for_bit == STAT_XFE)
@@ -226,7 +227,8 @@ static void tpm_wtx(struct tpm_chip *chip)
wait_and_send(chip, TPM_CTRL_WTX);
wait_and_send(chip, 0x00);
wait_and_send(chip, 0x00);
- msleep(TPM_WTX_MSLEEP_TIME);
+ usleep_range(TPM_WTX_USLEEP_TIME,
+ TPM_WTX_USLEEP_TIME + TPM_TIMEOUT_RANGE_US);
}
static void tpm_wtx_abort(struct tpm_chip *chip)
@@ -237,7 +239,8 @@ static void tpm_wtx_abort(struct tpm_chip *chip)
wait_and_send(chip, 0x00);
wait_and_send(chip, 0x00);
number_of_wtx = 0;
- msleep(TPM_WTX_MSLEEP_TIME);
+ usleep_range(TPM_WTX_USLEEP_TIME,
+ TPM_WTX_USLEEP_TIME + TPM_TIMEOUT_RANGE_US);
}
static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf, size_t count)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c0f296b..93e3233 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -51,7 +51,8 @@ static int wait_startup(struct tpm_chip *chip, int l)
if (access & TPM_ACCESS_VALID)
return 0;
- msleep(TPM_TIMEOUT);
+ usleep_range(TPM_TIMEOUT_US,
+ TPM_TIMEOUT_US + TPM_TIMEOUT_RANGE_US);
} while (time_before(jiffies, stop));
return -1;
}
@@ -125,7 +126,8 @@ again:
do {
if (check_locality(chip, l) >= 0)
return l;
- msleep(TPM_TIMEOUT);
+ usleep_range(TPM_TIMEOUT_US,
+ TPM_TIMEOUT_US + TPM_TIMEOUT_RANGE_US);
} while (time_before(jiffies, stop));
}
return -1;
@@ -170,7 +172,8 @@ static int get_burstcount(struct tpm_chip *chip)
burstcnt = (value >> 8) & 0xFFFF;
if (burstcnt)
return burstcnt;
- msleep(TPM_TIMEOUT);
+ usleep_range(TPM_TIMEOUT_US,
+ TPM_TIMEOUT_US + TPM_TIMEOUT_RANGE_US);
} while (time_before(jiffies, stop));
return -EBUSY;
}
@@ -408,7 +411,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf,
size_t len)
priv->irq = irq;
chip->flags |= TPM_CHIP_FLAG_IRQ;
if (!priv->irq_tested)
- msleep(1);
+ usleep_range(1000, 1000 + TPM_TIMEOUT_RANGE_US);
if (!priv->irq_tested)
disable_interrupts(chip);
priv->irq_tested = true;
--
2.7.4
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
tpmdd-devel mailing list
tpmdd-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
