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freebsd/sys/dev/amdsbwd/amdsbwd.c
Andriy Gapon fd63f40f93 amdsbwd: fix nonsensical timeout calculations
in case when sub-second interval is being programmed

Found by:	clang static analyzer
MFC after:	4 days
2010-05-31 09:07:23 +00:00

432 lines
11 KiB
C

/*-
* Copyright (c) 2009 Andriy Gapon <avg@FreeBSD.org>
* 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.
*/
/*
* This is a driver for watchdog timer present in AMD SB600/SB7xx
* south bridges and other watchdog timers advertised via WDRT ACPI table.
* Please see the following specifications for the descriptions of the
* registers and flags:
* - AMD SB600 Register Reference Guide, Public Version, Rev. 3.03 (SB600 RRG)
* http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/46155_sb600_rrg_pub_3.03.pdf
* - AMD SB700/710/750 Register Reference Guide (RRG)
* http://developer.amd.com/assets/43009_sb7xx_rrg_pub_1.00.pdf
* - AMD SB700/710/750 Register Programming Requirements (RPR)
* http://developer.amd.com/assets/42413_sb7xx_rpr_pub_1.00.pdf
* Please see the following for Watchdog Resource Table specification:
* - Watchdog Timer Hardware Requirements for Windows Server 2003 (WDRT)
* http://www.microsoft.com/whdc/system/sysinternals/watchdog.mspx
* AMD SB600/SB7xx watchdog hardware seems to conform to the above,
* but my system doesn't provide the table.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>
#include <sys/watchdog.h>
#include <dev/pci/pcivar.h>
#include <isa/isavar.h>
/* RRG 2.3.3.1.1, page 161. */
#define AMDSB_PMIO_INDEX 0xcd6
#define AMDSB_PMIO_DATA (PMIO_INDEX + 1)
#define AMDSB_PMIO_WIDTH 2
/* RRG 2.3.3.2, page 181. */
#define AMDSB_PM_RESET_STATUS0 0x44
#define AMDSB_PM_RESET_STATUS1 0x45
#define AMDSB_WD_RST_STS 0x02
/* RRG 2.3.3.2, page 188; RPR 2.36, page 30. */
#define AMDSB_PM_WDT_CTRL 0x69
#define AMDSB_WDT_DISABLE 0x01
#define AMDSB_WDT_RES_MASK (0x02 | 0x04)
#define AMDSB_WDT_RES_32US 0x00
#define AMDSB_WDT_RES_10MS 0x02
#define AMDSB_WDT_RES_100MS 0x04
#define AMDSB_WDT_RES_1S 0x06
#define AMDSB_PM_WDT_BASE_LSB 0x6c
#define AMDSB_PM_WDT_BASE_MSB 0x6f
/* RRG 2.3.4, page 223, WDRT. */
#define AMDSB_WD_CTRL 0x00
#define AMDSB_WD_RUN 0x01
#define AMDSB_WD_FIRED 0x02
#define AMDSB_WD_SHUTDOWN 0x04
#define AMDSB_WD_DISABLE 0x08
#define AMDSB_WD_RESERVED 0x70
#define AMDSB_WD_RELOAD 0x80
#define AMDSB_WD_COUNT 0x04
#define AMDSB_WD_COUNT_MASK 0xffff
#define AMDSB_WDIO_REG_WIDTH 4
/* WDRT */
#define MAXCOUNT_MIN_VALUE 511
/* RRG 2.3.1.1, page 122; SB600 RRG 2.3.1.1, page 97. */
#define AMDSB7xx_SMBUS_DEVID 0x43851002
#define amdsbwd_verbose_printf(dev, ...) \
do { \
if (bootverbose) \
device_printf(dev, __VA_ARGS__);\
} while (0)
struct amdsbwd_softc {
device_t dev;
eventhandler_tag ev_tag;
struct resource *res_ctrl;
struct resource *res_count;
int rid_ctrl;
int rid_count;
int ms_per_tick;
int max_ticks;
int active;
unsigned int timeout;
};
static void amdsbwd_identify(driver_t *driver, device_t parent);
static int amdsbwd_probe(device_t dev);
static int amdsbwd_attach(device_t dev);
static int amdsbwd_detach(device_t dev);
static device_method_t amdsbwd_methods[] = {
DEVMETHOD(device_identify, amdsbwd_identify),
DEVMETHOD(device_probe, amdsbwd_probe),
DEVMETHOD(device_attach, amdsbwd_attach),
DEVMETHOD(device_detach, amdsbwd_detach),
#if 0
DEVMETHOD(device_shutdown, amdsbwd_detach),
#endif
{0, 0}
};
static devclass_t amdsbwd_devclass;
static driver_t amdsbwd_driver = {
"amdsbwd",
amdsbwd_methods,
sizeof(struct amdsbwd_softc)
};
DRIVER_MODULE(amdsbwd, isa, amdsbwd_driver, amdsbwd_devclass, NULL, NULL);
static uint8_t
pmio_read(struct resource *res, uint8_t reg)
{
bus_write_1(res, 0, reg); /* Index */
return (bus_read_1(res, 1)); /* Data */
}
static void
pmio_write(struct resource *res, uint8_t reg, uint8_t val)
{
bus_write_1(res, 0, reg); /* Index */
bus_write_1(res, 1, val); /* Data */
}
static uint32_t
wdctrl_read(struct amdsbwd_softc *sc)
{
return (bus_read_4(sc->res_ctrl, 0));
}
static void
wdctrl_write(struct amdsbwd_softc *sc, uint32_t val)
{
bus_write_4(sc->res_ctrl, 0, val);
}
static __unused uint32_t
wdcount_read(struct amdsbwd_softc *sc)
{
return (bus_read_4(sc->res_count, 0));
}
static void
wdcount_write(struct amdsbwd_softc *sc, uint32_t val)
{
bus_write_4(sc->res_count, 0, val);
}
static void
amdsbwd_tmr_enable(struct amdsbwd_softc *sc)
{
uint32_t val;
val = wdctrl_read(sc);
val |= AMDSB_WD_RUN;
wdctrl_write(sc, val);
sc->active = 1;
amdsbwd_verbose_printf(sc->dev, "timer enabled\n");
}
static void
amdsbwd_tmr_disable(struct amdsbwd_softc *sc)
{
uint32_t val;
val = wdctrl_read(sc);
val &= ~AMDSB_WD_RUN;
wdctrl_write(sc, val);
sc->active = 0;
amdsbwd_verbose_printf(sc->dev, "timer disabled\n");
}
static void
amdsbwd_tmr_reload(struct amdsbwd_softc *sc)
{
uint32_t val;
val = wdctrl_read(sc);
val |= AMDSB_WD_RELOAD;
wdctrl_write(sc, val);
}
static void
amdsbwd_tmr_set(struct amdsbwd_softc *sc, uint16_t timeout)
{
timeout &= AMDSB_WD_COUNT_MASK;
wdcount_write(sc, timeout);
sc->timeout = timeout;
amdsbwd_verbose_printf(sc->dev, "timeout set to %u ticks\n", timeout);
}
static void
amdsbwd_event(void *arg, unsigned int cmd, int *error)
{
struct amdsbwd_softc *sc = arg;
unsigned int timeout;
/* convert from power-of-two-ns to WDT ticks */
cmd &= WD_INTERVAL;
if (cmd < WD_TO_1SEC)
cmd = 0;
if (cmd) {
timeout = ((uint64_t)1 << (cmd - WD_TO_1MS)) / sc->ms_per_tick;
if (timeout > sc->max_ticks)
timeout = sc->max_ticks;
if (timeout != sc->timeout) {
amdsbwd_tmr_set(sc, timeout);
if (!sc->active)
amdsbwd_tmr_enable(sc);
}
amdsbwd_tmr_reload(sc);
*error = 0;
} else {
if (sc->active)
amdsbwd_tmr_disable(sc);
}
}
static void
amdsbwd_identify(driver_t *driver, device_t parent)
{
device_t child;
device_t smb_dev;
if (resource_disabled("amdsbwd", 0))
return;
if (device_find_child(parent, "amdsbwd", -1) != NULL)
return;
/*
* Try to identify SB600/SB7xx by PCI Device ID of SMBus device
* that should be present at bus 0, device 20, function 0.
*/
smb_dev = pci_find_bsf(0, 20, 0);
if (smb_dev == NULL)
return;
if (pci_get_devid(smb_dev) != AMDSB7xx_SMBUS_DEVID)
return;
child = BUS_ADD_CHILD(parent, ISA_ORDER_SPECULATIVE, "amdsbwd", -1);
if (child == NULL)
device_printf(parent, "add amdsbwd child failed\n");
}
static int
amdsbwd_probe(device_t dev)
{
struct resource *res;
uint32_t addr;
uint32_t val;
int rid;
int rc;
int i;
/* Do not claim some ISA PnP device by accident. */
if (isa_get_logicalid(dev) != 0)
return (ENXIO);
rc = bus_set_resource(dev, SYS_RES_IOPORT, 0, AMDSB_PMIO_INDEX,
AMDSB_PMIO_WIDTH);
if (rc != 0) {
device_printf(dev, "bus_set_resource for IO failed\n");
return (ENXIO);
}
rid = 0;
res = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0ul, ~0ul,
AMDSB_PMIO_WIDTH, RF_ACTIVE | RF_SHAREABLE);
if (res == NULL) {
device_printf(dev, "bus_alloc_resource for IO failed\n");
return (ENXIO);
}
/* Report cause of previous reset for user's convenience. */
val = pmio_read(res, AMDSB_PM_RESET_STATUS0);
if (val != 0)
amdsbwd_verbose_printf(dev, "ResetStatus0 = %#04x\n", val);
val = pmio_read(res, AMDSB_PM_RESET_STATUS1);
if (val != 0)
amdsbwd_verbose_printf(dev, "ResetStatus1 = %#04x\n", val);
if ((val & AMDSB_WD_RST_STS) != 0)
device_printf(dev, "Previous Reset was caused by Watchdog\n");
/* Find base address of memory mapped WDT registers. */
for (addr = 0, i = 0; i < 4; i++) {
addr <<= 8;
addr |= pmio_read(res, AMDSB_PM_WDT_BASE_MSB - i);
}
amdsbwd_verbose_printf(dev, "memory base address = %#010x\n", addr);
rc = bus_set_resource(dev, SYS_RES_MEMORY, 0, addr + AMDSB_WD_CTRL,
AMDSB_WDIO_REG_WIDTH);
if (rc != 0) {
device_printf(dev, "bus_set_resource for control failed\n");
return (ENXIO);
}
rc = bus_set_resource(dev, SYS_RES_MEMORY, 1, addr + AMDSB_WD_COUNT,
AMDSB_WDIO_REG_WIDTH);
if (rc != 0) {
device_printf(dev, "bus_set_resource for count failed\n");
return (ENXIO);
}
/* Set watchdog timer tick to 10ms. */
val = pmio_read(res, AMDSB_PM_WDT_CTRL);
val &= ~AMDSB_WDT_RES_MASK;
val |= AMDSB_WDT_RES_10MS;
pmio_write(res, AMDSB_PM_WDT_CTRL, val);
/* Enable watchdog device (in stopped state). */
val = pmio_read(res, AMDSB_PM_WDT_CTRL);
val &= ~AMDSB_WDT_DISABLE;
pmio_write(res, AMDSB_PM_WDT_CTRL, val);
/*
* XXX TODO: Ensure that watchdog decode is enabled
* (register 0x41, bit 3).
*/
bus_release_resource(dev, SYS_RES_IOPORT, rid, res);
bus_delete_resource(dev, SYS_RES_IOPORT, rid);
device_set_desc(dev, "AMD SB600/SB7xx Watchdog Timer");
return (0);
}
static int
amdsbwd_attach_sb(device_t dev, struct amdsbwd_softc *sc)
{
sc->max_ticks = UINT16_MAX;
sc->ms_per_tick = 10;
sc->rid_ctrl = 0;
sc->rid_count = 1;
sc->res_ctrl = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->rid_ctrl, RF_ACTIVE);
if (sc->res_ctrl == NULL) {
device_printf(dev, "bus_alloc_resource for ctrl failed\n");
return (ENXIO);
}
sc->res_count = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->rid_count, RF_ACTIVE);
if (sc->res_count == NULL) {
device_printf(dev, "bus_alloc_resource for count failed\n");
return (ENXIO);
}
return (0);
}
static int
amdsbwd_attach(device_t dev)
{
struct amdsbwd_softc *sc;
int rc;
sc = device_get_softc(dev);
sc->dev = dev;
rc = amdsbwd_attach_sb(dev, sc);
if (rc != 0)
goto fail;
/* Setup initial state of Watchdog Control. */
wdctrl_write(sc, AMDSB_WD_FIRED);
if (wdctrl_read(sc) & AMDSB_WD_DISABLE) {
device_printf(dev, "watchdog hardware is disabled\n");
goto fail;
}
sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, amdsbwd_event, sc,
EVENTHANDLER_PRI_ANY);
return (0);
fail:
amdsbwd_detach(dev);
return (ENXIO);
}
static int
amdsbwd_detach(device_t dev)
{
struct amdsbwd_softc *sc;
sc = device_get_softc(dev);
if (sc->ev_tag != NULL)
EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
if (sc->active)
amdsbwd_tmr_disable(sc);
if (sc->res_ctrl != NULL)
bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_ctrl,
sc->res_ctrl);
if (sc->res_count != NULL)
bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_count,
sc->res_count);
return (0);
}