The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=38a4995eb52db21116f8b37ed942e66a8c2f050f
commit 38a4995eb52db21116f8b37ed942e66a8c2f050f Author: Kyle Evans <[email protected]> AuthorDate: 2026-02-05 03:35:01 +0000 Commit: Kyle Evans <[email protected]> CommitDate: 2026-02-05 03:35:10 +0000 tpm20: fix suspend/resume and entropy harvesting There were a few problem here: - TPM2_Shutdown results in a response that we need to either process or ignore, otherwise any tpm20_write or tpm20_harvest call will trivially hang on an `sc->pending_data_length != 0` - We should have a matching TPM2_Startup upon resume to restore any state that should have persisted - We must drain the harvest task before we suspend to avoid problems there This commit is sufficient to avoid breaking suspend/resume. PR: 291067 Fixes: a2d5ed9442bb ("Introduce driver for TPM 2.0 in CRB and [...]") Fixes: 4ee7d3b0118c ("Allow using TPM as entropy source.") Co-authored-by: markj (D53835) Tested by: garga Differential Revision: https://reviews.freebsd.org/D55074 --- sys/dev/tpm/tpm20.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++ sys/dev/tpm/tpm20.h | 1 + sys/dev/tpm/tpm_crb.c | 1 + sys/dev/tpm/tpm_tis_core.c | 1 + 4 files changed, 68 insertions(+) diff --git a/sys/dev/tpm/tpm20.c b/sys/dev/tpm/tpm20.c index 6c587818058d..c521ca9dda9d 100644 --- a/sys/dev/tpm/tpm20.c +++ b/sys/dev/tpm/tpm20.c @@ -45,6 +45,7 @@ static void tpm20_discard_buffer(void *arg); #if defined TPM_HARVEST || defined RANDOM_ENABLE_TPM static void tpm20_harvest(void *arg, int unused); #endif +static int tpm20_restart(device_t dev, bool clear); static int tpm20_save_state(device_t dev, bool suspend); static d_open_t tpm20_open; @@ -242,9 +243,31 @@ tpm20_release(struct tpm_sc *sc) destroy_dev(sc->sc_cdev); } +int +tpm20_resume(device_t dev) +{ + + tpm20_restart(dev, false); + +#if defined TPM_HARVEST || defined RANDOM_ENABLE_TPM + struct tpm_sc *sc; + + sc = device_get_softc(dev); + taskqueue_enqueue_timeout(taskqueue_thread, &sc->harvest_task, + hz * TPM_HARVEST_INTERVAL); +#endif + return (0); +} + int tpm20_suspend(device_t dev) { +#if defined TPM_HARVEST || defined RANDOM_ENABLE_TPM + struct tpm_sc *sc; + + sc = device_get_softc(dev); + taskqueue_drain_timeout(taskqueue_thread, &sc->harvest_task); +#endif return (tpm20_save_state(dev, true)); } @@ -307,6 +330,43 @@ tpm20_harvest(void *arg, int unused) } #endif /* TPM_HARVEST */ +static int +tpm20_restart(device_t dev, bool clear) +{ + struct tpm_sc *sc; + uint8_t startup_cmd[] = { + 0x80, 0x01, /* TPM_ST_NO_SESSIONS tag*/ + 0x00, 0x00, 0x00, 0x0C, /* cmd length */ + 0x00, 0x00, 0x01, 0x44, /* cmd TPM_CC_Startup */ + 0x00, 0x01 /* TPM_SU_STATE */ + }; + + sc = device_get_softc(dev); + + /* + * Inform the TPM whether we are resetting or resuming. + */ + if (clear) + startup_cmd[11] = 0; /* TPM_SU_CLEAR */ + + if (sc == NULL || sc->buf == NULL) + return (0); + + sx_xlock(&sc->dev_lock); + + MPASS(sc->pending_data_length == 0); + memcpy(sc->buf, startup_cmd, sizeof(startup_cmd)); + + /* XXX Ignoring both TPM_TRANSMIT return and tpm's response */ + TPM_TRANSMIT(sc->dev, sizeof(startup_cmd)); + sc->pending_data_length = 0; + sc->total_length = 0; + + sx_xunlock(&sc->dev_lock); + + return (0); +} + static int tpm20_save_state(device_t dev, bool suspend) { @@ -331,8 +391,13 @@ tpm20_save_state(device_t dev, bool suspend) sx_xlock(&sc->dev_lock); + MPASS(sc->pending_data_length == 0); memcpy(sc->buf, save_cmd, sizeof(save_cmd)); + + /* XXX Ignoring both TPM_TRANSMIT return and tpm's response */ TPM_TRANSMIT(sc->dev, sizeof(save_cmd)); + sc->pending_data_length = 0; + sc->total_length = 0; sx_xunlock(&sc->dev_lock); diff --git a/sys/dev/tpm/tpm20.h b/sys/dev/tpm/tpm20.h index b2cfcd4f25bd..96b2920283b6 100644 --- a/sys/dev/tpm/tpm20.h +++ b/sys/dev/tpm/tpm20.h @@ -136,6 +136,7 @@ struct tpm_sc { }; int tpm20_suspend(device_t dev); +int tpm20_resume(device_t dev); int tpm20_shutdown(device_t dev); int32_t tpm20_get_timeout(uint32_t command); int tpm20_init(struct tpm_sc *sc); diff --git a/sys/dev/tpm/tpm_crb.c b/sys/dev/tpm/tpm_crb.c index 26b53e7a621d..18414a6c799b 100644 --- a/sys/dev/tpm/tpm_crb.c +++ b/sys/dev/tpm/tpm_crb.c @@ -651,6 +651,7 @@ static device_method_t tpmcrb_methods[] = { DEVMETHOD(device_detach, tpmcrb_detach), DEVMETHOD(device_shutdown, tpm20_shutdown), DEVMETHOD(device_suspend, tpm20_suspend), + DEVMETHOD(device_resume, tpm20_resume), DEVMETHOD(tpm_transmit, tpmcrb_transmit), {0, 0} }; diff --git a/sys/dev/tpm/tpm_tis_core.c b/sys/dev/tpm/tpm_tis_core.c index 4159de4daf3b..34ecfcc283b1 100644 --- a/sys/dev/tpm/tpm_tis_core.c +++ b/sys/dev/tpm/tpm_tis_core.c @@ -487,6 +487,7 @@ static device_method_t tpmtis_methods[] = { DEVMETHOD(device_detach, tpmtis_detach), DEVMETHOD(device_shutdown, tpm20_shutdown), DEVMETHOD(device_suspend, tpm20_suspend), + DEVMETHOD(device_resume, tpm20_resume), DEVMETHOD(tpm_transmit, tpmtis_transmit), DEVMETHOD_END };
