diff options
Diffstat (limited to 'sys/dev/acpica/acpi_timer.c')
| -rw-r--r-- | sys/dev/acpica/acpi_timer.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/sys/dev/acpica/acpi_timer.c b/sys/dev/acpica/acpi_timer.c new file mode 100644 index 0000000..67e308a --- /dev/null +++ b/sys/dev/acpica/acpi_timer.c @@ -0,0 +1,389 @@ +/*- + * Copyright (c) 2000, 2001 Michael Smith + * Copyright (c) 2000 BSDi + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ +#include "opt_acpi.h" +#include <sys/param.h> +#include <sys/bus.h> +#include <sys/kernel.h> +#include <sys/sysctl.h> +#if __FreeBSD_version >= 500000 +#include <sys/timetc.h> +#else +#include <sys/time.h> +#endif + +#include <machine/bus.h> +#include <machine/resource.h> +#include <sys/rman.h> + +#include "acpi.h" + +#include <dev/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 + */ +#define _COMPONENT ACPI_SYSTEM +ACPI_MODULE_NAME("TIMER") + +static device_t acpi_timer_dev; +struct resource *acpi_timer_reg; + +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 unsigned acpi_timer_get_timecount(struct timecounter *tc); +static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc); +static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS); +static void acpi_timer_test(void); + +static u_int32_t read_counter(void); +static int test_counter(void); + +/* + * Driver hung off ACPI. + */ +static device_method_t acpi_timer_methods[] = { + DEVMETHOD(device_identify, acpi_timer_identify), + DEVMETHOD(device_probe, acpi_timer_probe), + DEVMETHOD(device_attach, acpi_timer_attach), + + {0, 0} +}; + +static driver_t acpi_timer_driver = { + "acpi_timer", + acpi_timer_methods, + 0, +}; + +static devclass_t acpi_timer_devclass; +DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0); + +/* + * Timecounter. + */ +static struct timecounter acpi_timer_timecounter = { + acpi_timer_get_timecount_safe, + 0, + 0xffffff, + 0, + "ACPI" +}; + + +static u_int32_t +read_counter() +{ + bus_space_handle_t bsh; + bus_space_tag_t bst; + u_int32_t tv; + + bsh = rman_get_bushandle(acpi_timer_reg); + bst = rman_get_bustag(acpi_timer_reg); + tv = bus_space_read_4(bst, bsh, 0); + bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ); + return (tv); +} + +#define N 2000 +static int +test_counter() +{ + int min, max, n, delta; + unsigned last, this; + + min = 10000000; + max = 0; + last = read_counter(); + for (n = 0; n < N; n++) { + this = read_counter(); + delta = (this - last) & 0xffffff; + if (delta > max) + max = delta; + else if (delta < min) + min = delta; + last = this; + } + if (max - min > 2) + n = 0; + else if (min < 0 || max == 0) + n = 0; + else + n = 1; + if (bootverbose) + printf("ACPI timer looks %s min = %d, max = %d, width = %d\n", + n ? "GOOD" : "BAD ", + min, max, max - min); + return (n); +} + +/* + * 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]; + u_long rlen, rstart; + int i, j, rid, rtype; + + ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); + + if (acpi_disabled("timer")) + return_VOID; + + if (AcpiGbl_FADT == NULL) + return_VOID; + + if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) { + device_printf(parent, "could not add acpi_timer0\n"); + return_VOID; + } + acpi_timer_dev = dev; + + rid = 0; + rlen = AcpiGbl_FADT->PmTmLen; + rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId) + ? SYS_RES_IOPORT : SYS_RES_MEMORY; + rstart = AcpiGbl_FADT->XPmTmrBlk.Address; + bus_set_resource(dev, rtype, rid, rstart, rlen); + acpi_timer_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE); + if (acpi_timer_reg == NULL) { + device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n", + (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart); + return_VOID; + } + if (testenv("debug.acpi.timer_test")) + acpi_timer_test(); + + acpi_timer_timecounter.tc_frequency = acpi_timer_frequency; + j = 0; + for(i = 0; i < 10; i++) + j += test_counter(); + if (j == 10) { + acpi_timer_timecounter.tc_name = "ACPI-fast"; + acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; + } else { + acpi_timer_timecounter.tc_name = "ACPI-safe"; + acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe; + } + tc_init(&acpi_timer_timecounter); + + sprintf(desc, "%d-bit timer at 3.579545MHz", (AcpiGbl_FADT->TmrValExt) + ? 32 : 24); + device_set_desc_copy(dev, desc); + + return_VOID; +} + +static int +acpi_timer_probe(device_t dev) +{ + if (dev == acpi_timer_dev) + return(0); + return(ENXIO); +} + +static int +acpi_timer_attach(device_t dev) +{ + return(0); +} + +/* + * Fetch current time value from reliable hardware. + */ +static unsigned +acpi_timer_get_timecount(struct timecounter *tc) +{ + return (read_counter()); +} + +/* + * Fetch current time value from hardware that may not correctly + * latch the counter. + */ +static unsigned +acpi_timer_get_timecount_safe(struct timecounter *tc) +{ + unsigned u1, u2, u3; + + u2 = read_counter(); + u3 = read_counter(); + do { + u1 = u2; + u2 = u3; + u3 = read_counter(); + } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15); + return (u2); +} + +/* + * 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; + } + 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 = read_counter(); + u2 = read_counter(); + u3 = read_counter(); + + 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 = read_counter(); + } +} + +/* + * Chipset workaround driver hung off PCI. + * + * Some ACPI timers are known or believed to suffer from implementation + * problems which can lead to erroneous values being read from the timer. + * + * Since we can't trust unknown chipsets, we default to a timer-read + * routine which compensates for the most common problem (as detailed + * in the excerpt from the Intel PIIX4 datasheet below). + * + * When we detect a known-functional chipset, we disable the workaround + * to improve speed. + * + * ] 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, it is fixed + * ] in the PIIX4M. + * + * 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. + */ + +#if 0 +static int acpi_timer_pci_probe(device_t dev); + +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); + +/* + * Look at PCI devices going past; if we detect one we know contains + * a functional ACPI timer device, enable the faster timecounter read + * routine. + */ +static int +acpi_timer_pci_probe(device_t dev) +{ + int vendor, device, revid; + + vendor = pci_get_vendor(dev); + device = pci_get_device(dev); + revid = pci_get_revid(dev); + + if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */ + ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */ + 0) { + + acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount; + acpi_timer_timecounter.tc_name = "ACPI-fast"; + if (bootverbose) + device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n"); + } + + return(ENXIO); /* we never match anything */ +} +#endif |
