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Commit 8e54caf4 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Peter Huewe
Browse files

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: <stable@vger.kernel.org>
[PHuewe: without this fix these 'broken' Atmel TPMs won't function on
older kernels]
Signed-off-by: default avatar"Berg, Christopher" <Christopher.Berg@atmel.com>
Signed-off-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>

Signed-off-by: default avatarPeter Huewe <peterhuewe@gmx.de>
parent 3e14d83e

drivers/char/tpm/tpm-interface.c

+41 −21
Original line number Diff line number Diff line
@@ -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;

	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 */

	timeout = be32_to_cpu(timeout_cap->a);

	if (timeout && timeout < 1000) {

		if (new_timeout[0] != 0 && new_timeout[0] < 1000) {

			int i;



			/* timeouts in msec rather usec */

		scale = 1000;

			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;

drivers/char/tpm/tpm_tis.c

+31 −0
Original line number Diff line number Diff line
@@ -373,6 +373,36 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) 
	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,

include/linux/tpm.h

+3 −0
Original line number Diff line number Diff line
@@ -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)