[PATCH 3.12 043/142] tpm: Provide a generic means to override the chip returned timeouts

From: Jiri Slaby
Date: Fri Sep 26 2014 - 05:57:47 EST


From: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 8e54caf407b98efa05409e1fee0e5381abd2b088 upstream.

Some Atmel TPMs provide completely wrong timeouts from their
TPM_CAP_PROP_TIS_TIMEOUT query. This patch detects that and returns
new correct values via a DID/VID table in the TIS driver.

Tested on ARM using an AT97SC3204T FW version 37.16

[PHuewe: without this fix these 'broken' Atmel TPMs won't function on
older kernels]
Signed-off-by: "Berg, Christopher" <Christopher.Berg@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Huewe <peterhuewe@xxxxxx>
[bwh: Backported to 3.10:
- Adjust filename, context
- s/chip->ops->/chip->vendor./]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/char/tpm/tpm.c | 62 ++++++++++++++++++++++++++++++----------------
drivers/char/tpm/tpm.h | 3 +++
drivers/char/tpm/tpm_tis.c | 31 +++++++++++++++++++++++
3 files changed, 75 insertions(+), 21 deletions(-)

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 334b9ef1bb1d..48138b311460 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -533,11 +533,10 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
int tpm_get_timeouts(struct tpm_chip *chip)
{
struct tpm_cmd_t tpm_cmd;
- struct timeout_t *timeout_cap;
+ unsigned long new_timeout[4];
+ unsigned long old_timeout[4];
struct duration_t *duration_cap;
ssize_t rc;
- u32 timeout;
- unsigned int scale = 1;

tpm_cmd.header.in = tpm_getcap_header;
tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
@@ -571,25 +570,46 @@ int tpm_get_timeouts(struct tpm_chip *chip)
!= sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
return -EINVAL;

- timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
- /* Don't overwrite default if value is 0 */
- timeout = be32_to_cpu(timeout_cap->a);
- if (timeout && timeout < 1000) {
- /* timeouts in msec rather usec */
- scale = 1000;
- chip->vendor.timeout_adjusted = true;
+ old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
+ old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
+ old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
+ old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
+ memcpy(new_timeout, old_timeout, sizeof(new_timeout));
+
+ /*
+ * Provide ability for vendor overrides of timeout values in case
+ * of misreporting.
+ */
+ if (chip->vendor.update_timeouts != NULL)
+ chip->vendor.timeout_adjusted =
+ chip->vendor.update_timeouts(chip, new_timeout);
+
+ if (!chip->vendor.timeout_adjusted) {
+ /* Don't overwrite default if value is 0 */
+ if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
+ int i;
+
+ /* timeouts in msec rather usec */
+ for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
+ new_timeout[i] *= 1000;
+ chip->vendor.timeout_adjusted = true;
+ }
}
- if (timeout)
- chip->vendor.timeout_a = usecs_to_jiffies(timeout * scale);
- timeout = be32_to_cpu(timeout_cap->b);
- if (timeout)
- chip->vendor.timeout_b = usecs_to_jiffies(timeout * scale);
- timeout = be32_to_cpu(timeout_cap->c);
- if (timeout)
- chip->vendor.timeout_c = usecs_to_jiffies(timeout * scale);
- timeout = be32_to_cpu(timeout_cap->d);
- if (timeout)
- chip->vendor.timeout_d = usecs_to_jiffies(timeout * scale);
+
+ /* Report adjusted timeouts */
+ if (chip->vendor.timeout_adjusted) {
+ dev_info(chip->dev,
+ HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
+ old_timeout[0], new_timeout[0],
+ old_timeout[1], new_timeout[1],
+ old_timeout[2], new_timeout[2],
+ old_timeout[3], new_timeout[3]);
+ }
+
+ chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
+ chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
+ chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
+ chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);

duration:
tpm_cmd.header.in = tpm_getcap_header;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index a7bfc176ed43..b911d79fbd58 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -95,6 +95,9 @@ struct tpm_vendor_specific {
int (*send) (struct tpm_chip *, u8 *, size_t);
void (*cancel) (struct tpm_chip *);
u8 (*status) (struct tpm_chip *);
+ bool (*update_timeouts)(struct tpm_chip *chip,
+ unsigned long *timeout_cap);
+
void (*release) (struct device *);
struct miscdevice miscdev;
struct attribute_group *attr_group;
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 5796d0157ce0..e7b1a0ae4300 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -373,6 +373,36 @@ out_err:
return rc;
}

+struct tis_vendor_timeout_override {
+ u32 did_vid;
+ unsigned long timeout_us[4];
+};
+
+static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
+ /* Atmel 3204 */
+ { 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
+ (TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
+};
+
+static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
+ unsigned long *timeout_cap)
+{
+ int i;
+ u32 did_vid;
+
+ did_vid = ioread32(chip->vendor.iobase + TPM_DID_VID(0));
+
+ for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
+ if (vendor_timeout_overrides[i].did_vid != did_vid)
+ continue;
+ memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
+ sizeof(vendor_timeout_overrides[i].timeout_us));
+ return true;
+ }
+
+ return false;
+}
+
/*
* Early probing for iTPM with STS_DATA_EXPECT flaw.
* Try sending command without itpm flag set and if that
@@ -475,6 +505,7 @@ static struct tpm_vendor_specific tpm_tis = {
.recv = tpm_tis_recv,
.send = tpm_tis_send,
.cancel = tpm_tis_ready,
+ .update_timeouts = tpm_tis_update_timeouts,
.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_canceled = tpm_tis_req_canceled,
--
2.1.0

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