From 8e54caf407b98efa05409e1fee0e5381abd2b088 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 21 May 2014 18:26:44 -0600 Subject: [PATCH] tpm: Provide a generic means to override the chip returned timeouts 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 Cc: [PHuewe: without this fix these 'broken' Atmel TPMs won't function on older kernels] Signed-off-by: "Berg, Christopher" Signed-off-by: Jason Gunthorpe Signed-off-by: Peter Huewe --- drivers/char/tpm/tpm-interface.c | 62 +++++++++++++++++++++----------- drivers/char/tpm/tpm_tis.c | 31 ++++++++++++++++ include/linux/tpm.h | 3 ++ 3 files changed, 75 insertions(+), 21 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index bef6cceffc3a..6af17002a115 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -491,11 +491,10 @@ 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; @@ -529,25 +528,46 @@ 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->ops->update_timeouts != NULL) + chip->vendor.timeout_adjusted = + chip->ops->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_tis.c b/drivers/char/tpm/tpm_tis.c index a9ed2270c25d..2c46734b266d 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 @@ -437,6 +467,7 @@ static const struct tpm_class_ops 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, diff --git a/include/linux/tpm.h b/include/linux/tpm.h index fff1d0976f80..8350c538b486 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -39,6 +39,9 @@ struct tpm_class_ops { int (*send) (struct tpm_chip *chip, u8 *buf, size_t len); void (*cancel) (struct tpm_chip *chip); u8 (*status) (struct tpm_chip *chip); + bool (*update_timeouts)(struct tpm_chip *chip, + unsigned long *timeout_cap); + }; #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE) -- 2.20.1