My PC would hang on almost every shutdown/suspend until I started testing this patch and so far in the past week I haven’t experienced any problems anymore. I suspect that the root cause on my specific board is that after the ACPI command to put the device to S3 or S5, some firmware application/driver will try to use the TPM chip expecting it to be in Locality 0 as expected by TCG PC Client Platform Firmware Profile Version 1.06 Revision 52 (3.1.1 – Pre-OS Environment) and then when it fails to do so it simply halts the whole system. This issue might be related to the following bug: https://bugzilla.kernel.org/show_bug.cgi?id=217890 Enable a user to configure the kernel through “tpm.locality_on_suspend=1” boot parameter so that the locality is set before suspend/shutdown in order to diagnose whether or not the board is one of the buggy ones that require this workaround. Since this bug is related to the board/platform instead of the specific TPM chip, call dmi_check_system on the tpm_init function so that this setting is automatically enabled for boards specified in code (ASUS TUF GAMING B460M-PLUS already included) – automatic configuration only works in case CONFIG_DMI is set though, since dmi_check_system is a non-op when CONFIG_DMI is not set. In case “tpm.locality_on_suspend=0” (the default) don't change any behavior thus preserving current functionality of any other board except ASUSTeK COMPUTER INC. TUF GAMING B460M-PLUS and possibly future boards as we successfully diagnose other boards with the same issue fixed by using “tpm.locality_on_suspend=1”. Signed-off-by: Adam Alves <adamoa@xxxxxxxxx> --- drivers/char/tpm/tpm-chip.c | 9 ++++++++ drivers/char/tpm/tpm-interface.c | 36 +++++++++++++++++++++++++++++++- drivers/char/tpm/tpm.h | 1 + include/linux/tpm.h | 1 + 4 files changed, 46 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 42b1062e33cd..8fdf7a137a94 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -139,6 +139,9 @@ void tpm_chip_stop(struct tpm_chip *chip) { tpm_go_idle(chip); tpm_relinquish_locality(chip); + // If locality is to be preserved, we need to make sure it is Locality 0. + if (chip->flags & TPM_CHIP_PRESERVE_LOCALITY) + tpm_request_locality(chip); tpm_clk_disable(chip); } EXPORT_SYMBOL_GPL(tpm_chip_stop); @@ -291,6 +294,9 @@ int tpm_class_shutdown(struct device *dev) { struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); + if (tpm_locality_on_suspend) + chip->flags |= TPM_CHIP_PRESERVE_LOCALITY; + down_write(&chip->ops_sem); if (chip->flags & TPM_CHIP_FLAG_TPM2) { if (!tpm_chip_start(chip)) { @@ -668,6 +674,9 @@ EXPORT_SYMBOL_GPL(tpm_chip_register); */ void tpm_chip_unregister(struct tpm_chip *chip) { + if (tpm_locality_on_suspend) + chip->flags |= TPM_CHIP_PRESERVE_LOCALITY; + tpm_del_legacy_sysfs(chip); if (tpm_is_hwrng_enabled(chip)) hwrng_unregister(&chip->hwrng); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 66b16d26eecc..8aeea2dee0a8 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -26,6 +26,7 @@ #include <linux/suspend.h> #include <linux/freezer.h> #include <linux/tpm_eventlog.h> +#include <linux/dmi.h> #include "tpm.h" @@ -382,6 +383,34 @@ int tpm_auto_startup(struct tpm_chip *chip) return rc; } +/* + * Bug workaround - some boards expect the TPM to be on ready + * state before suspend/shutdown, otherwise suspend and shutdown might + * hang the system, so we need to adjust suspend code for handling this. + */ +bool tpm_locality_on_suspend; +module_param_named(locality_on_suspend, tpm_locality_on_suspend, bool, 0644); +MODULE_PARM_DESC(locality_on_suspend, "The firmware expects TPM to be at locality 0 before suspend/shutdown."); + +static int __init tpm_set_locality_on_suspend(const struct dmi_system_id *system_id) +{ + pr_info("Board %s: TPM locality preserved before suspend/shutdown.\n", system_id->ident); + tpm_locality_on_suspend = true; + + return 0; +} + +static const struct dmi_system_id tpm_board_quirks[] __initconst = { + { + .ident = "TUF GAMING B460M-PLUS", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC."), + DMI_MATCH(DMI_BOARD_NAME, "TUF GAMING B460M-PLUS"), + }, + .callback = tpm_set_locality_on_suspend, + }, +}; + /* * We are about to suspend. Save the TPM state * so that it can be restored. @@ -394,6 +423,9 @@ int tpm_pm_suspend(struct device *dev) if (!chip) return -ENODEV; + if (tpm_locality_on_suspend) + chip->flags |= TPM_CHIP_PRESERVE_LOCALITY; + if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED) goto suspended; @@ -431,7 +463,7 @@ int tpm_pm_resume(struct device *dev) if (chip == NULL) return -ENODEV; - chip->flags &= ~TPM_CHIP_FLAG_SUSPENDED; + chip->flags &= ~(TPM_CHIP_PRESERVE_LOCALITY | TPM_CHIP_FLAG_SUSPENDED); /* * Guarantee that SUSPENDED is written last, so that hwrng does not @@ -476,6 +508,8 @@ static int __init tpm_init(void) { int rc; + dmi_check_system(tpm_board_quirks); + rc = class_register(&tpm_class); if (rc) { pr_err("couldn't create tpm class\n"); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 61445f1dc46d..f2657b611b81 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -236,6 +236,7 @@ extern dev_t tpm_devt; extern const struct file_operations tpm_fops; extern const struct file_operations tpmrm_fops; extern struct idr dev_nums_idr; +extern bool tpm_locality_on_suspend; ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz); int tpm_get_timeouts(struct tpm_chip *); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 4ee9d13749ad..7717f484ac25 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -284,6 +284,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_FIRMWARE_UPGRADE = BIT(7), TPM_CHIP_FLAG_SUSPENDED = BIT(8), TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9), + TPM_CHIP_PRESERVE_LOCALITY = BIT(10), }; #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) -- 2.44.0
