diff options
Diffstat (limited to 'sys/dev/acpica/acpi_timer.c')
-rw-r--r-- | sys/dev/acpica/acpi_timer.c | 227 |
1 files changed, 207 insertions, 20 deletions
diff --git a/sys/dev/acpica/acpi_timer.c b/sys/dev/acpica/acpi_timer.c index 9581dae..0ed8d82 100644 --- a/sys/dev/acpica/acpi_timer.c +++ b/sys/dev/acpica/acpi_timer.c @@ -1,5 +1,5 @@ /*- - * Copyright (c) 2000 Michael Smith + * Copyright (c) 2000, 2001 Michael Smith * Copyright (c) 2000 BSDi * All rights reserved. * @@ -26,15 +26,36 @@ * * $FreeBSD$ */ - +/* + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + */ #include "opt_acpi.h" #include <sys/param.h> -#include <sys/kernel.h> #include <sys/bus.h> +#include <sys/kernel.h> +#include <sys/sysctl.h> +#include <sys/timetc.h> + +#include <machine/bus_pio.h> +#include <machine/bus.h> +#include <machine/resource.h> +#include <sys/rman.h> #include "acpi.h" -#include <dev/acpica/acpivar.h> +#include <acpica/acpivar.h> +#include <pci/pcivar.h> + +/* + * A timecounter based on the free-running ACPI timer. + * + * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>. + */ /* * Hooks for the ACPI CA debugging infrastructure @@ -42,18 +63,49 @@ #define _COMPONENT ACPI_SYSTEM MODULE_NAME("TIMER") -#define ACPITIMER_MAGIC 0x524d4954 /* "TIMR" */ +static device_t acpi_timer_dev; +struct resource *acpi_timer_reg; +#define TIMER_READ bus_space_read_4(rman_get_bustag(acpi_timer_reg), \ + rman_get_bushandle(acpi_timer_reg), \ + 0) +static int acpi_timer_flags; +/* + * ] 20. ACPI Timer Errata + * ] + * ] Problem: The power management timer may return improper result when + * ] read. Although the timer value settles properly after incrementing, + * ] while incrementing there is a 3nS window every 69.8nS where the + * ] timer value is indeterminate (a 4.2% chance that the data will be + * ] incorrect when read). As a result, the ACPI free running count up + * ] timer specification is violated due to erroneous reads. Implication: + * ] System hangs due to the "inaccuracy" of the timer when used by + * ] software for time critical events and delays. + * ] + * ] Workaround: Read the register twice and compare. + * ] Status: This will not be fixed in the PIIX4 or PIIX4E. + * + * The counter is in other words not latched to the PCI bus clock when + * read. Notice the workaround isn't: We need to read until we have + * three monotonic samples and then use the middle one, otherwise we are + * not protected against the fact that the bits can be wrong in two + * directions. If we only cared about monosity two reads would be enough. + */ +#define TFLAG_NEED_PIIX_WAR (1 << 0) -struct acpi_timer_softc { - device_t tm_dev; -}; +static u_int acpi_timer_frequency = 14318182/4; static void acpi_timer_identify(driver_t *driver, device_t parent); static int acpi_timer_probe(device_t dev); static int acpi_timer_attach(device_t dev); +static int acpi_timer_pci_probe(device_t dev); +static unsigned acpi_timer_get_timecount(struct timecounter *tc); +static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); +static void acpi_timer_test(void); +/* + * Driver hung off ACPI. + */ static device_method_t acpi_timer_methods[] = { - /* Device interface */ DEVMETHOD(device_identify, acpi_timer_identify), DEVMETHOD(device_probe, acpi_timer_probe), DEVMETHOD(device_attach, acpi_timer_attach), @@ -64,17 +116,53 @@ static device_method_t acpi_timer_methods[] = { static driver_t acpi_timer_driver = { "acpi_timer", acpi_timer_methods, - sizeof(struct acpi_timer_softc), + 0, }; devclass_t acpi_timer_devclass; DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); +/* + * Chipset workaround driver hung off PCI. + */ +static device_method_t acpi_timer_pci_methods[] = { + DEVMETHOD(device_probe, acpi_timer_pci_probe), + {0, 0} +}; + +static driver_t acpi_timer_pci_driver = { + "acpi_timer_pci", + acpi_timer_pci_methods, + 0, +}; + +devclass_t acpi_timer_pci_devclass; +DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0); + +/* + * Timecounter. + */ +static struct timecounter acpi_timer_timecounter = { + acpi_timer_get_timecount, + 0, + 0xffffff, + 0, + "ACPI" +}; + +SYSCTL_OPAQUE(_debug, OID_AUTO, acpi_timecounter, CTLFLAG_RD, + &acpi_timer_timecounter, sizeof(acpi_timer_timecounter), "S,timecounter", ""); + +/* + * Locate the ACPI timer using the FADT, set up and allocate the I/O resources + * we will be using. + */ static void acpi_timer_identify(driver_t *driver, device_t parent) { - device_t dev; - char desc[40]; + device_t dev; + char desc[40]; + int rid; FUNCTION_TRACE(__func__); @@ -88,10 +176,18 @@ acpi_timer_identify(driver_t *driver, device_t parent) device_printf(parent, "could not add acpi_timer0\n"); return_VOID; } - if (acpi_set_magic(dev, ACPITIMER_MAGIC)) { - device_printf(dev, "could not set magic\n"); + acpi_timer_dev = dev; + rid = 0; + bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t)); + if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) { + device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk); return_VOID; } + if (getenv("debug.acpi.timer_test") != NULL) + acpi_timer_test(); + + acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; + tc_init(&acpi_timer_timecounter); sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24); device_set_desc_copy(dev, desc); @@ -102,7 +198,7 @@ acpi_timer_identify(driver_t *driver, device_t parent) static int acpi_timer_probe(device_t dev) { - if (acpi_get_magic(dev) == ACPITIMER_MAGIC) + if (dev == acpi_timer_dev) return(0); return(ENXIO); } @@ -110,12 +206,103 @@ acpi_timer_probe(device_t dev) static int acpi_timer_attach(device_t dev) { - struct acpi_timer_softc *sc; + return(0); +} - FUNCTION_TRACE(__func__); +/* + * Look at PCI devices as they go past, and if we detect a PIIX4, set + * the PIIX_WAR flag. + * + * XXX do we know that other timecounters work? Interesting question. + */ +static int +acpi_timer_pci_probe(device_t dev) +{ + if ((pci_get_vendor(dev) == 0x8086) && + (pci_get_device(dev) == 0x7113)) { + acpi_timer_flags |= TFLAG_NEED_PIIX_WAR; + device_printf(acpi_timer_dev, "enabling PIIX4 timer workaround\n"); + } - sc = device_get_softc(dev); - sc->tm_dev = dev; + return(ENXIO); /* we never match anything */ +} - return_VALUE(0); +/* + * Fetch current time value from hardware. + * + * XXX This is currently written to be "correct", not + * "fast". Optimisation is strongly indicated. + */ +static unsigned +acpi_timer_get_timecount(struct timecounter *tc) +{ + unsigned u1, u2, u3; + + if (acpi_timer_flags & TFLAG_NEED_PIIX_WAR) { + u2 = TIMER_READ; + u3 = TIMER_READ; + do { + u1 = u2; + u2 = u3; + u3 = TIMER_READ; + } while (u1 > u2 || u2 > u3); + return (u2); + } else { + return(TIMER_READ); + } } + +/* + * Timecounter freqency adjustment interface. + */ +static int +acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS) +{ + int error; + u_int freq; + + if (acpi_timer_timecounter.tc_frequency == 0) + return (EOPNOTSUPP); + freq = acpi_timer_frequency; + error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); + if (error == 0 && req->newptr != NULL) { + acpi_timer_frequency = freq; + acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; + tc_update(&acpi_timer_timecounter); + } + return (error); +} + +SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW, + 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", ""); + +/* + * Test harness for verifying ACPI timer behaviour. + * Boot with debug.acpi.timer_test set to invoke this. + */ +static void +acpi_timer_test(void) +{ + u_int32_t u1, u2, u3; + + u1 = TIMER_READ; + u2 = TIMER_READ; + u3 = TIMER_READ; + + device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n"); + for (;;) { + /* + * The failure case is where u3 > u1, but u2 does not fall between the two, + * ie. it contains garbage. + */ + if (u3 > u1) { + if ((u2 < u1) || (u2 > u3)) + device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n", + u1, u2, u3); + } + u1 = u2; + u2 = u3; + u3 = TIMER_READ; + } +} + |