From: Stephen Boyd swboyd@chromium.org
[ Upstream commit 2e2ee5a2db06c4b81315514b01d06fe5644342e9 ]
On some platforms, the TPM power is managed by firmware and therefore we don't need to stop the TPM on suspend when going to a light version of suspend such as S0ix ("freeze" suspend state). Add a chip flag, TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED, to indicate this so that certain platforms can probe for the usage of this light suspend and avoid touching the TPM state across suspend/resume.
Cc: Andrey Pronin apronin@chromium.org Cc: Duncan Laurie dlaurie@chromium.org Cc: Jason Gunthorpe jgg@ziepe.ca Cc: Arnd Bergmann arnd@arndb.de Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Guenter Roeck groeck@chromium.org Cc: Alexander Steffen Alexander.Steffen@infineon.com Cc: Heiko Stuebner heiko@sntech.de Tested-by: Heiko Stuebner heiko@sntech.de Reviewed-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Stephen Boyd swboyd@chromium.org Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/tpm/tpm-interface.c | 8 +++++++- drivers/char/tpm/tpm.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index d7a3888ad80f0..7f105490604c8 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -23,6 +23,7 @@ #include <linux/slab.h> #include <linux/mutex.h> #include <linux/spinlock.h> +#include <linux/suspend.h> #include <linux/freezer.h> #include <linux/tpm_eventlog.h>
@@ -394,7 +395,11 @@ int tpm_pm_suspend(struct device *dev) return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED) - return 0; + goto suspended; + + if ((chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) && + !pm_suspend_via_firmware()) + goto suspended;
if (!tpm_chip_start(chip)) { if (chip->flags & TPM_CHIP_FLAG_TPM2) @@ -405,6 +410,7 @@ int tpm_pm_suspend(struct device *dev) tpm_chip_stop(chip); }
+suspended: return rc; } EXPORT_SYMBOL_GPL(tpm_pm_suspend); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index a7fea3e0ca86a..f3bf2f7f755c8 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -162,6 +162,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_VIRTUAL = BIT(3), TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4), TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5), + TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED = BIT(6), };
#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)