linux/drivers/char/tpm/tpm_tis_core.c
Alexander Steffen 513253f8c2 tpm_tis: Explicitly check for error code
recv_data either returns the number of received bytes, or a negative value
representing an error code. Adding the return value directly to the total
number of received bytes therefore looks a little weird, since it might add
a negative error code to a sum of bytes.

The following check for size < expected usually makes the function return
ETIME in that case, so it does not cause too many problems in practice. But
to make the code look cleaner and because the caller might still be
interested in the original error code, explicitly check for the presence of
an error code and pass that through.

Cc: stable@vger.kernel.org
Fixes: cb5354253a ("[PATCH] tpm: spacing cleanups 2")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2023-07-28 18:13:39 +00:00

1340 lines
32 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2005, 2006 IBM Corporation
* Copyright (C) 2014, 2015 Intel Corporation
*
* Authors:
* Leendert van Doorn <leendert@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*
* This device driver implements the TPM interface as defined in
* the TCG TPM Interface Spec version 1.2, revision 1.0.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pnp.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/acpi.h>
#include <linux/freezer.h>
#include <linux/dmi.h>
#include "tpm.h"
#include "tpm_tis_core.h"
#define TPM_TIS_MAX_UNHANDLED_IRQS 1000
static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
bool check_cancel, bool *canceled)
{
u8 status = chip->ops->status(chip);
*canceled = false;
if ((status & mask) == mask)
return true;
if (check_cancel && chip->ops->req_canceled(chip, status)) {
*canceled = true;
return true;
}
return false;
}
static u8 tpm_tis_filter_sts_mask(u8 int_mask, u8 sts_mask)
{
if (!(int_mask & TPM_INTF_STS_VALID_INT))
sts_mask &= ~TPM_STS_VALID;
if (!(int_mask & TPM_INTF_DATA_AVAIL_INT))
sts_mask &= ~TPM_STS_DATA_AVAIL;
if (!(int_mask & TPM_INTF_CMD_READY_INT))
sts_mask &= ~TPM_STS_COMMAND_READY;
return sts_mask;
}
static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
unsigned long timeout, wait_queue_head_t *queue,
bool check_cancel)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
unsigned long stop;
long rc;
u8 status;
bool canceled = false;
u8 sts_mask;
int ret = 0;
/* check current status */
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
sts_mask = mask & (TPM_STS_VALID | TPM_STS_DATA_AVAIL |
TPM_STS_COMMAND_READY);
/* check what status changes can be handled by irqs */
sts_mask = tpm_tis_filter_sts_mask(priv->int_mask, sts_mask);
stop = jiffies + timeout;
/* process status changes with irq support */
if (sts_mask) {
ret = -ETIME;
again:
timeout = stop - jiffies;
if ((long)timeout <= 0)
return -ETIME;
rc = wait_event_interruptible_timeout(*queue,
wait_for_tpm_stat_cond(chip, sts_mask, check_cancel,
&canceled),
timeout);
if (rc > 0) {
if (canceled)
return -ECANCELED;
ret = 0;
}
if (rc == -ERESTARTSYS && freezing(current)) {
clear_thread_flag(TIF_SIGPENDING);
goto again;
}
}
if (ret)
return ret;
mask &= ~sts_mask;
if (!mask) /* all done */
return 0;
/* process status changes without irq support */
do {
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
usleep_range(priv->timeout_min,
priv->timeout_max);
} while (time_before(jiffies, stop));
return -ETIME;
}
/* Before we attempt to access the TPM we must see that the valid bit is set.
* The specification says that this bit is 0 at reset and remains 0 until the
* 'TPM has gone through its self test and initialization and has established
* correct values in the other bits.'
*/
static int wait_startup(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
unsigned long stop = jiffies + chip->timeout_a;
do {
int rc;
u8 access;
rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
if (rc < 0)
return rc;
if (access & TPM_ACCESS_VALID)
return 0;
tpm_msleep(TPM_TIMEOUT);
} while (time_before(jiffies, stop));
return -1;
}
static bool check_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc;
u8 access;
rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
if (rc < 0)
return false;
if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID
| TPM_ACCESS_REQUEST_USE)) ==
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
priv->locality = l;
return true;
}
return false;
}
static int __tpm_tis_relinquish_locality(struct tpm_tis_data *priv, int l)
{
tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
return 0;
}
static int tpm_tis_relinquish_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
mutex_lock(&priv->locality_count_mutex);
priv->locality_count--;
if (priv->locality_count == 0)
__tpm_tis_relinquish_locality(priv, l);
mutex_unlock(&priv->locality_count_mutex);
return 0;
}
static int __tpm_tis_request_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
unsigned long stop, timeout;
long rc;
if (check_locality(chip, l))
return l;
rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
if (rc < 0)
return rc;
stop = jiffies + chip->timeout_a;
if (chip->flags & TPM_CHIP_FLAG_IRQ) {
again:
timeout = stop - jiffies;
if ((long)timeout <= 0)
return -1;
rc = wait_event_interruptible_timeout(priv->int_queue,
(check_locality
(chip, l)),
timeout);
if (rc > 0)
return l;
if (rc == -ERESTARTSYS && freezing(current)) {
clear_thread_flag(TIF_SIGPENDING);
goto again;
}
} else {
/* wait for burstcount */
do {
if (check_locality(chip, l))
return l;
tpm_msleep(TPM_TIMEOUT);
} while (time_before(jiffies, stop));
}
return -1;
}
static int tpm_tis_request_locality(struct tpm_chip *chip, int l)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int ret = 0;
mutex_lock(&priv->locality_count_mutex);
if (priv->locality_count == 0)
ret = __tpm_tis_request_locality(chip, l);
if (!ret)
priv->locality_count++;
mutex_unlock(&priv->locality_count_mutex);
return ret;
}
static u8 tpm_tis_status(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc;
u8 status;
rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
if (rc < 0)
return 0;
if (unlikely((status & TPM_STS_READ_ZERO) != 0)) {
if (!test_and_set_bit(TPM_TIS_INVALID_STATUS, &priv->flags)) {
/*
* If this trips, the chances are the read is
* returning 0xff because the locality hasn't been
* acquired. Usually because tpm_try_get_ops() hasn't
* been called before doing a TPM operation.
*/
dev_err(&chip->dev, "invalid TPM_STS.x 0x%02x, dumping stack for forensics\n",
status);
/*
* Dump stack for forensics, as invalid TPM_STS.x could be
* potentially triggered by impaired tpm_try_get_ops() or
* tpm_find_get_ops().
*/
dump_stack();
}
return 0;
}
return status;
}
static void tpm_tis_ready(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
/* this causes the current command to be aborted */
tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
}
static int get_burstcount(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
unsigned long stop;
int burstcnt, rc;
u32 value;
/* wait for burstcount */
if (chip->flags & TPM_CHIP_FLAG_TPM2)
stop = jiffies + chip->timeout_a;
else
stop = jiffies + chip->timeout_d;
do {
rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
if (rc < 0)
return rc;
burstcnt = (value >> 8) & 0xFFFF;
if (burstcnt)
return burstcnt;
usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX);
} while (time_before(jiffies, stop));
return -EBUSY;
}
static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int size = 0, burstcnt, rc;
while (size < count) {
rc = wait_for_tpm_stat(chip,
TPM_STS_DATA_AVAIL | TPM_STS_VALID,
chip->timeout_c,
&priv->read_queue, true);
if (rc < 0)
return rc;
burstcnt = get_burstcount(chip);
if (burstcnt < 0) {
dev_err(&chip->dev, "Unable to read burstcount\n");
return burstcnt;
}
burstcnt = min_t(int, burstcnt, count - size);
rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
burstcnt, buf + size);
if (rc < 0)
return rc;
size += burstcnt;
}
return size;
}
static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int size = 0;
int status;
u32 expected;
int rc;
if (count < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
size = recv_data(chip, buf, TPM_HEADER_SIZE);
/* read first 10 bytes, including tag, paramsize, and result */
if (size < TPM_HEADER_SIZE) {
dev_err(&chip->dev, "Unable to read header\n");
goto out;
}
expected = be32_to_cpu(*(__be32 *) (buf + 2));
if (expected > count || expected < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
rc = recv_data(chip, &buf[TPM_HEADER_SIZE],
expected - TPM_HEADER_SIZE);
if (rc < 0) {
size = rc;
goto out;
}
size += rc;
if (size < expected) {
dev_err(&chip->dev, "Unable to read remainder of result\n");
size = -ETIME;
goto out;
}
if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
&priv->int_queue, false) < 0) {
size = -ETIME;
goto out;
}
status = tpm_tis_status(chip);
if (status & TPM_STS_DATA_AVAIL) { /* retry? */
dev_err(&chip->dev, "Error left over data\n");
size = -EIO;
goto out;
}
rc = tpm_tis_verify_crc(priv, (size_t)size, buf);
if (rc < 0) {
dev_err(&chip->dev, "CRC mismatch for response.\n");
size = rc;
goto out;
}
out:
tpm_tis_ready(chip);
return size;
}
/*
* If interrupts are used (signaled by an irq set in the vendor structure)
* tpm.c can skip polling for the data to be available as the interrupt is
* waited for here
*/
static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc, status, burstcnt;
size_t count = 0;
bool itpm = test_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags);
status = tpm_tis_status(chip);
if ((status & TPM_STS_COMMAND_READY) == 0) {
tpm_tis_ready(chip);
if (wait_for_tpm_stat
(chip, TPM_STS_COMMAND_READY, chip->timeout_b,
&priv->int_queue, false) < 0) {
rc = -ETIME;
goto out_err;
}
}
while (count < len - 1) {
burstcnt = get_burstcount(chip);
if (burstcnt < 0) {
dev_err(&chip->dev, "Unable to read burstcount\n");
rc = burstcnt;
goto out_err;
}
burstcnt = min_t(int, burstcnt, len - count - 1);
rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
burstcnt, buf + count);
if (rc < 0)
goto out_err;
count += burstcnt;
if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
&priv->int_queue, false) < 0) {
rc = -ETIME;
goto out_err;
}
status = tpm_tis_status(chip);
if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
rc = -EIO;
goto out_err;
}
}
/* write last byte */
rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
if (rc < 0)
goto out_err;
if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
&priv->int_queue, false) < 0) {
rc = -ETIME;
goto out_err;
}
status = tpm_tis_status(chip);
if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
rc = -EIO;
goto out_err;
}
return 0;
out_err:
tpm_tis_ready(chip);
return rc;
}
static void __tpm_tis_disable_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 int_mask = 0;
tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &int_mask);
int_mask &= ~TPM_GLOBAL_INT_ENABLE;
tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), int_mask);
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
}
static void tpm_tis_disable_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
if (priv->irq == 0)
return;
__tpm_tis_disable_interrupts(chip);
devm_free_irq(chip->dev.parent, priv->irq, chip);
priv->irq = 0;
}
/*
* If interrupts are used (signaled by an irq set in the vendor structure)
* tpm.c can skip polling for the data to be available as the interrupt is
* waited for here
*/
static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc;
u32 ordinal;
unsigned long dur;
rc = tpm_tis_send_data(chip, buf, len);
if (rc < 0)
return rc;
rc = tpm_tis_verify_crc(priv, len, buf);
if (rc < 0) {
dev_err(&chip->dev, "CRC mismatch for command.\n");
return rc;
}
/* go and do it */
rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
if (rc < 0)
goto out_err;
if (chip->flags & TPM_CHIP_FLAG_IRQ) {
ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
dur = tpm_calc_ordinal_duration(chip, ordinal);
if (wait_for_tpm_stat
(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
&priv->read_queue, false) < 0) {
rc = -ETIME;
goto out_err;
}
}
return 0;
out_err:
tpm_tis_ready(chip);
return rc;
}
static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
{
int rc, irq;
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
if (!(chip->flags & TPM_CHIP_FLAG_IRQ) ||
test_bit(TPM_TIS_IRQ_TESTED, &priv->flags))
return tpm_tis_send_main(chip, buf, len);
/* Verify receipt of the expected IRQ */
irq = priv->irq;
priv->irq = 0;
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
rc = tpm_tis_send_main(chip, buf, len);
priv->irq = irq;
chip->flags |= TPM_CHIP_FLAG_IRQ;
if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags))
tpm_msleep(1);
if (!test_bit(TPM_TIS_IRQ_TESTED, &priv->flags))
tpm_tis_disable_interrupts(chip);
set_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
return rc;
}
struct tis_vendor_durations_override {
u32 did_vid;
struct tpm1_version version;
unsigned long durations[3];
};
static const struct tis_vendor_durations_override vendor_dur_overrides[] = {
/* STMicroelectronics 0x104a */
{ 0x0000104a,
{ 1, 2, 8, 28 },
{ (2 * 60 * HZ), (2 * 60 * HZ), (2 * 60 * HZ) } },
};
static void tpm_tis_update_durations(struct tpm_chip *chip,
unsigned long *duration_cap)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
struct tpm1_version *version;
u32 did_vid;
int i, rc;
cap_t cap;
chip->duration_adjusted = false;
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, true);
rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed to read did_vid. %d\n",
__func__, rc);
goto out;
}
/* Try to get a TPM version 1.2 or 1.1 TPM_CAP_VERSION_INFO */
rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
"attempting to determine the 1.2 version",
sizeof(cap.version2));
if (!rc) {
version = &cap.version2.version;
} else {
rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
"attempting to determine the 1.1 version",
sizeof(cap.version1));
if (rc)
goto out;
version = &cap.version1;
}
for (i = 0; i != ARRAY_SIZE(vendor_dur_overrides); i++) {
if (vendor_dur_overrides[i].did_vid != did_vid)
continue;
if ((version->major ==
vendor_dur_overrides[i].version.major) &&
(version->minor ==
vendor_dur_overrides[i].version.minor) &&
(version->rev_major ==
vendor_dur_overrides[i].version.rev_major) &&
(version->rev_minor ==
vendor_dur_overrides[i].version.rev_minor)) {
memcpy(duration_cap,
vendor_dur_overrides[i].durations,
sizeof(vendor_dur_overrides[i].durations));
chip->duration_adjusted = true;
goto out;
}
}
out:
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
}
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 void tpm_tis_update_timeouts(struct tpm_chip *chip,
unsigned long *timeout_cap)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int i, rc;
u32 did_vid;
chip->timeout_adjusted = false;
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, true);
rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
if (rc < 0) {
dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
__func__, rc);
goto out;
}
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));
chip->timeout_adjusted = true;
}
out:
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
return;
}
/*
* Early probing for iTPM with STS_DATA_EXPECT flaw.
* Try sending command without itpm flag set and if that
* fails, repeat with itpm flag set.
*/
static int probe_itpm(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
int rc = 0;
static const u8 cmd_getticks[] = {
0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
0x00, 0x00, 0x00, 0xf1
};
size_t len = sizeof(cmd_getticks);
u16 vendor;
if (test_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags))
return 0;
rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
if (rc < 0)
return rc;
/* probe only iTPMS */
if (vendor != TPM_VID_INTEL)
return 0;
if (tpm_tis_request_locality(chip, 0) != 0)
return -EBUSY;
rc = tpm_tis_send_data(chip, cmd_getticks, len);
if (rc == 0)
goto out;
tpm_tis_ready(chip);
set_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags);
rc = tpm_tis_send_data(chip, cmd_getticks, len);
if (rc == 0)
dev_info(&chip->dev, "Detected an iTPM.\n");
else {
clear_bit(TPM_TIS_ITPM_WORKAROUND, &priv->flags);
rc = -EFAULT;
}
out:
tpm_tis_ready(chip);
tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
if (!test_bit(TPM_TIS_DEFAULT_CANCELLATION, &priv->flags)) {
switch (priv->manufacturer_id) {
case TPM_VID_WINBOND:
return ((status == TPM_STS_VALID) ||
(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
case TPM_VID_STM:
return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
default:
break;
}
}
return status == TPM_STS_COMMAND_READY;
}
static irqreturn_t tpm_tis_revert_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
const char *product;
const char *vendor;
dev_warn(&chip->dev, FW_BUG
"TPM interrupt storm detected, polling instead\n");
vendor = dmi_get_system_info(DMI_SYS_VENDOR);
product = dmi_get_system_info(DMI_PRODUCT_VERSION);
if (vendor && product) {
dev_info(&chip->dev,
"Consider adding the following entry to tpm_tis_dmi_table:\n");
dev_info(&chip->dev, "\tDMI_SYS_VENDOR: %s\n", vendor);
dev_info(&chip->dev, "\tDMI_PRODUCT_VERSION: %s\n", product);
}
if (tpm_tis_request_locality(chip, 0) != 0)
return IRQ_NONE;
__tpm_tis_disable_interrupts(chip);
tpm_tis_relinquish_locality(chip, 0);
schedule_work(&priv->free_irq_work);
return IRQ_HANDLED;
}
static irqreturn_t tpm_tis_update_unhandled_irqs(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
irqreturn_t irqret = IRQ_HANDLED;
if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
return IRQ_HANDLED;
if (time_after(jiffies, priv->last_unhandled_irq + HZ/10))
priv->unhandled_irqs = 1;
else
priv->unhandled_irqs++;
priv->last_unhandled_irq = jiffies;
if (priv->unhandled_irqs > TPM_TIS_MAX_UNHANDLED_IRQS)
irqret = tpm_tis_revert_interrupts(chip);
return irqret;
}
static irqreturn_t tis_int_handler(int dummy, void *dev_id)
{
struct tpm_chip *chip = dev_id;
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 interrupt;
int rc;
rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
if (rc < 0)
goto err;
if (interrupt == 0)
goto err;
set_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
if (interrupt & TPM_INTF_DATA_AVAIL_INT)
wake_up_interruptible(&priv->read_queue);
if (interrupt &
(TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
TPM_INTF_CMD_READY_INT))
wake_up_interruptible(&priv->int_queue);
/* Clear interrupts handled with TPM_EOI */
tpm_tis_request_locality(chip, 0);
rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
tpm_tis_relinquish_locality(chip, 0);
if (rc < 0)
goto err;
tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
return IRQ_HANDLED;
err:
return tpm_tis_update_unhandled_irqs(chip);
}
static void tpm_tis_gen_interrupt(struct tpm_chip *chip)
{
const char *desc = "attempting to generate an interrupt";
u32 cap2;
cap_t cap;
int ret;
chip->flags |= TPM_CHIP_FLAG_IRQ;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
ret = tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
else
ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
if (ret)
chip->flags &= ~TPM_CHIP_FLAG_IRQ;
}
static void tpm_tis_free_irq_func(struct work_struct *work)
{
struct tpm_tis_data *priv = container_of(work, typeof(*priv), free_irq_work);
struct tpm_chip *chip = priv->chip;
devm_free_irq(chip->dev.parent, priv->irq, chip);
priv->irq = 0;
}
/* Register the IRQ and issue a command that will cause an interrupt. If an
* irq is seen then leave the chip setup for IRQ operation, otherwise reverse
* everything and leave in polling mode. Returns 0 on success.
*/
static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
int flags, int irq)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u8 original_int_vec;
int rc;
u32 int_status;
INIT_WORK(&priv->free_irq_work, tpm_tis_free_irq_func);
rc = devm_request_threaded_irq(chip->dev.parent, irq, NULL,
tis_int_handler, IRQF_ONESHOT | flags,
dev_name(&chip->dev), chip);
if (rc) {
dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
irq);
return -1;
}
priv->irq = irq;
rc = tpm_tis_request_locality(chip, 0);
if (rc < 0)
return rc;
rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
&original_int_vec);
if (rc < 0) {
tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
if (rc < 0)
goto restore_irqs;
rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
if (rc < 0)
goto restore_irqs;
/* Clear all existing */
rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
if (rc < 0)
goto restore_irqs;
/* Turn on */
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
intmask | TPM_GLOBAL_INT_ENABLE);
if (rc < 0)
goto restore_irqs;
clear_bit(TPM_TIS_IRQ_TESTED, &priv->flags);
/* Generate an interrupt by having the core call through to
* tpm_tis_send
*/
tpm_tis_gen_interrupt(chip);
restore_irqs:
/* tpm_tis_send will either confirm the interrupt is working or it
* will call disable_irq which undoes all of the above.
*/
if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
tpm_tis_write8(priv, original_int_vec,
TPM_INT_VECTOR(priv->locality));
rc = -1;
}
tpm_tis_relinquish_locality(chip, priv->locality);
return rc;
}
/* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
* do not have ACPI/etc. We typically expect the interrupt to be declared if
* present.
*/
static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u8 original_int_vec;
int i, rc;
rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
&original_int_vec);
if (rc < 0)
return;
if (!original_int_vec) {
if (IS_ENABLED(CONFIG_X86))
for (i = 3; i <= 15; i++)
if (!tpm_tis_probe_irq_single(chip, intmask, 0,
i))
return;
} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
original_int_vec))
return;
}
void tpm_tis_remove(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 reg = TPM_INT_ENABLE(priv->locality);
u32 interrupt;
int rc;
tpm_tis_clkrun_enable(chip, true);
rc = tpm_tis_read32(priv, reg, &interrupt);
if (rc < 0)
interrupt = 0;
tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
flush_work(&priv->free_irq_work);
tpm_tis_clkrun_enable(chip, false);
if (priv->ilb_base_addr)
iounmap(priv->ilb_base_addr);
}
EXPORT_SYMBOL_GPL(tpm_tis_remove);
/**
* tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
* of a single TPM command
* @chip: TPM chip to use
* @value: 1 - Disable CLKRUN protocol, so that clocks are free running
* 0 - Enable CLKRUN protocol
* Call this function directly in tpm_tis_remove() in error or driver removal
* path, since the chip->ops is set to NULL in tpm_chip_unregister().
*/
static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
{
struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
u32 clkrun_val;
if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
!data->ilb_base_addr)
return;
if (value) {
data->clkrun_enabled++;
if (data->clkrun_enabled > 1)
return;
clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
/* Disable LPC CLKRUN# */
clkrun_val &= ~LPC_CLKRUN_EN;
iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
/*
* Write any random value on port 0x80 which is on LPC, to make
* sure LPC clock is running before sending any TPM command.
*/
outb(0xCC, 0x80);
} else {
data->clkrun_enabled--;
if (data->clkrun_enabled)
return;
clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
/* Enable LPC CLKRUN# */
clkrun_val |= LPC_CLKRUN_EN;
iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
/*
* Write any random value on port 0x80 which is on LPC, to make
* sure LPC clock is running before sending any TPM command.
*/
outb(0xCC, 0x80);
}
}
static const struct tpm_class_ops tpm_tis = {
.flags = TPM_OPS_AUTO_STARTUP,
.status = tpm_tis_status,
.recv = tpm_tis_recv,
.send = tpm_tis_send,
.cancel = tpm_tis_ready,
.update_timeouts = tpm_tis_update_timeouts,
.update_durations = tpm_tis_update_durations,
.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,
.request_locality = tpm_tis_request_locality,
.relinquish_locality = tpm_tis_relinquish_locality,
.clk_enable = tpm_tis_clkrun_enable,
};
int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
const struct tpm_tis_phy_ops *phy_ops,
acpi_handle acpi_dev_handle)
{
u32 vendor;
u32 intfcaps;
u32 intmask;
u32 clkrun_val;
u8 rid;
int rc, probe;
struct tpm_chip *chip;
chip = tpmm_chip_alloc(dev, &tpm_tis);
if (IS_ERR(chip))
return PTR_ERR(chip);
#ifdef CONFIG_ACPI
chip->acpi_dev_handle = acpi_dev_handle;
#endif
chip->hwrng.quality = priv->rng_quality;
/* Maximum timeouts */
chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
priv->chip = chip;
priv->timeout_min = TPM_TIMEOUT_USECS_MIN;
priv->timeout_max = TPM_TIMEOUT_USECS_MAX;
priv->phy_ops = phy_ops;
priv->locality_count = 0;
mutex_init(&priv->locality_count_mutex);
dev_set_drvdata(&chip->dev, priv);
rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
if (rc < 0)
return rc;
priv->manufacturer_id = vendor;
if (priv->manufacturer_id == TPM_VID_ATML &&
!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
priv->timeout_min = TIS_TIMEOUT_MIN_ATML;
priv->timeout_max = TIS_TIMEOUT_MAX_ATML;
}
if (is_bsw()) {
priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
ILB_REMAP_SIZE);
if (!priv->ilb_base_addr)
return -ENOMEM;
clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
/* Check if CLKRUN# is already not enabled in the LPC bus */
if (!(clkrun_val & LPC_CLKRUN_EN)) {
iounmap(priv->ilb_base_addr);
priv->ilb_base_addr = NULL;
}
}
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, true);
if (wait_startup(chip, 0) != 0) {
rc = -ENODEV;
goto out_err;
}
/* Take control of the TPM's interrupt hardware and shut it off */
rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
if (rc < 0)
goto out_err;
/* Figure out the capabilities */
rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
if (rc < 0)
goto out_err;
dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
intfcaps);
if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
dev_dbg(dev, "\tBurst Count Static\n");
if (intfcaps & TPM_INTF_CMD_READY_INT) {
intmask |= TPM_INTF_CMD_READY_INT;
dev_dbg(dev, "\tCommand Ready Int Support\n");
}
if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
dev_dbg(dev, "\tInterrupt Edge Falling\n");
if (intfcaps & TPM_INTF_INT_EDGE_RISING)
dev_dbg(dev, "\tInterrupt Edge Rising\n");
if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
dev_dbg(dev, "\tInterrupt Level Low\n");
if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
dev_dbg(dev, "\tInterrupt Level High\n");
if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT) {
intmask |= TPM_INTF_LOCALITY_CHANGE_INT;
dev_dbg(dev, "\tLocality Change Int Support\n");
}
if (intfcaps & TPM_INTF_STS_VALID_INT) {
intmask |= TPM_INTF_STS_VALID_INT;
dev_dbg(dev, "\tSts Valid Int Support\n");
}
if (intfcaps & TPM_INTF_DATA_AVAIL_INT) {
intmask |= TPM_INTF_DATA_AVAIL_INT;
dev_dbg(dev, "\tData Avail Int Support\n");
}
intmask &= ~TPM_GLOBAL_INT_ENABLE;
rc = tpm_tis_request_locality(chip, 0);
if (rc < 0) {
rc = -ENODEV;
goto out_err;
}
tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
tpm_tis_relinquish_locality(chip, 0);
rc = tpm_chip_start(chip);
if (rc)
goto out_err;
rc = tpm2_probe(chip);
tpm_chip_stop(chip);
if (rc)
goto out_err;
rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
if (rc < 0)
goto out_err;
dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
(chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
vendor >> 16, rid);
probe = probe_itpm(chip);
if (probe < 0) {
rc = -ENODEV;
goto out_err;
}
/* INTERRUPT Setup */
init_waitqueue_head(&priv->read_queue);
init_waitqueue_head(&priv->int_queue);
rc = tpm_chip_bootstrap(chip);
if (rc)
goto out_err;
if (irq != -1) {
/*
* Before doing irq testing issue a command to the TPM in polling mode
* to make sure it works. May as well use that command to set the
* proper timeouts for the driver.
*/
rc = tpm_tis_request_locality(chip, 0);
if (rc < 0)
goto out_err;
rc = tpm_get_timeouts(chip);
tpm_tis_relinquish_locality(chip, 0);
if (rc) {
dev_err(dev, "Could not get TPM timeouts and durations\n");
rc = -ENODEV;
goto out_err;
}
if (irq)
tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
irq);
else
tpm_tis_probe_irq(chip, intmask);
if (chip->flags & TPM_CHIP_FLAG_IRQ) {
priv->int_mask = intmask;
} else {
dev_err(&chip->dev, FW_BUG
"TPM interrupt not working, polling instead\n");
rc = tpm_tis_request_locality(chip, 0);
if (rc < 0)
goto out_err;
tpm_tis_disable_interrupts(chip);
tpm_tis_relinquish_locality(chip, 0);
}
}
rc = tpm_chip_register(chip);
if (rc)
goto out_err;
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
return 0;
out_err:
if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
tpm_tis_remove(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_tis_core_init);
#ifdef CONFIG_PM_SLEEP
static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
u32 intmask;
int rc;
/*
* Re-enable interrupts that device may have lost or BIOS/firmware may
* have disabled.
*/
rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
if (rc < 0) {
dev_err(&chip->dev, "Setting IRQ failed.\n");
return;
}
intmask = priv->int_mask | TPM_GLOBAL_INT_ENABLE;
rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
if (rc < 0)
dev_err(&chip->dev, "Enabling interrupts failed.\n");
}
int tpm_tis_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
int ret;
ret = tpm_chip_start(chip);
if (ret)
return ret;
if (chip->flags & TPM_CHIP_FLAG_IRQ)
tpm_tis_reenable_interrupts(chip);
/*
* TPM 1.2 requires self-test on resume. This function actually returns
* an error code but for unknown reason it isn't handled.
*/
if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
tpm1_do_selftest(chip);
tpm_chip_stop(chip);
ret = tpm_pm_resume(dev);
if (ret)
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_tis_resume);
#endif
MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");