Hi, tpm(4) is the last driver in the tree using tvtohz(9). There are no remaining callers using tstohz(9), so if and when we remove tvtohz(9) from tpm(4) we can remove both interfaces from the tree.
tpm(4) is tricky because it converts timeouts from milliseconds to ticks and then doesn't use tsleep(9) at all. It uses delay(9), which takes a count of microseconds as argument. This complicates the conversion to tsleep_nsec(9) because the units don't match up for any of these delays. Also, delay(9) is incompatible with tsleep(9) because tsleep(9) yields the CPU while delay(9) busy-waits. I don't know if we *need* to delay(9) here. What would happen if we yielded the CPU with e.g. tsleep(9)? The attached patch changes the delays to use the correct units. This is not the right thing, these timeouts are probably too large to spin for in delay(9). I'm just guessing here. Aside: TPM_READ_TMO is *huge*. 2 minutes for a read timeout seems a bit large. NetBSD's TPM_READ_TMO has been dropped to 2 seconds, like the other timeouts. Also perhaps of note is that NetBSD's tpm(4) driver mostly no longer uses delay(9). They use tsleep(9) in all but one spot: https://github.com/NetBSD/src/blob/fc83762bc464be0bf351901b2c387a8cfedff7c4/sys/dev/ic/tpm.c Index: tpm.c =================================================================== RCS file: /cvs/src/sys/dev/acpi/tpm.c,v retrieving revision 1.10 diff -u -p -r1.10 tpm.c --- tpm.c 22 May 2020 10:16:37 -0000 1.10 +++ tpm.c 19 Dec 2020 00:56:02 -0000 @@ -158,7 +158,6 @@ int tpm_request_locality(struct tpm_soft void tpm_release_locality(struct tpm_softc *); int tpm_getburst(struct tpm_softc *); uint8_t tpm_status(struct tpm_softc *); -int tpm_tmotohz(int); struct cfattach tpm_ca = { sizeof(struct tpm_softc), @@ -372,7 +371,7 @@ int tpm_request_locality(struct tpm_softc *sc, int l) { uint32_t r; - int to; + int msecs; if (l != 0) return EINVAL; @@ -385,12 +384,12 @@ tpm_request_locality(struct tpm_softc *s bus_space_write_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS, TPM_ACCESS_REQUEST_USE); - to = tpm_tmotohz(TPM_ACCESS_TMO); - - while ((r = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS) & - (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != - (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY) && to--) { - DELAY(10); + for (msecs = 0; msecs < TPM_ACCESS_TMO; msecs++) { + r = bus_space_read_1(sc->sc_bt, sc->sc_bh, TPM_ACCESS); + if ((r & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) == + (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) + break; + DELAY(1000); } if ((r & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) != @@ -418,12 +417,10 @@ tpm_release_locality(struct tpm_softc *s int tpm_getburst(struct tpm_softc *sc) { - int burst, burst2, to; - - to = tpm_tmotohz(TPM_BURST_TMO); + int burst, burst2, msecs; burst = 0; - while (burst == 0 && to--) { + for (msecs = 0; msecs < TPM_BURST_TMO; msecs++) { /* * Burst count has to be read from bits 8 to 23 without * touching any other bits, eg. the actual status bits 0 to 7. @@ -438,7 +435,7 @@ tpm_getburst(struct tpm_softc *sc) if (burst) return burst; - DELAY(10); + DELAY(1000); } DPRINTF(("%s: getburst timed out\n", sc->sc_dev.dv_xname)); @@ -453,30 +450,19 @@ tpm_status(struct tpm_softc *sc) } int -tpm_tmotohz(int tmo) -{ - struct timeval tv; - - tv.tv_sec = tmo / 1000; - tv.tv_usec = 1000 * (tmo % 1000); - - return tvtohz(&tv); -} - -int -tpm_waitfor(struct tpm_softc *sc, uint8_t mask, int tries) +tpm_waitfor(struct tpm_softc *sc, uint8_t mask, int msecs) { uint8_t status; while (((status = tpm_status(sc)) & mask) != mask) { - if (tries == 0) { + if (msecs <= 0) { DPRINTF(("%s: %s: timed out, status 0x%x != 0x%x\n", sc->sc_dev.dv_xname, __func__, status, mask)); return status; } - tries--; - DELAY(1); + msecs -= 1000; + DELAY(1000); } return 0;
