/* * Virtual hardware watchdog. * * Copyright (C) 2009 Red Hat Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * By Richard W.M. Jones (rjones@redhat.com). */ #include "qemu/osdep.h" #include "qemu/module.h" #include "qemu/timer.h" #include "sysemu/watchdog.h" #include "hw/pci/pci_device.h" #include "migration/vmstate.h" #include "qom/object.h" /*#define I6300ESB_DEBUG 1*/ #ifdef I6300ESB_DEBUG #define i6300esb_debug(fs,...) \ fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__) #else #define i6300esb_debug(fs,...) #endif /* PCI configuration registers */ #define ESB_CONFIG_REG 0x60 /* Config register */ #define ESB_LOCK_REG 0x68 /* WDT lock register */ /* Memory mapped registers (offset from base address) */ #define ESB_TIMER1_REG 0x00 /* Timer1 value after each reset */ #define ESB_TIMER2_REG 0x04 /* Timer2 value after each reset */ #define ESB_GINTSR_REG 0x08 /* General Interrupt Status Register */ #define ESB_RELOAD_REG 0x0c /* Reload register */ /* Lock register bits */ #define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */ #define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */ #define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */ /* Config register bits */ #define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */ #define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */ #define ESB_WDT_INTTYPE (0x11 << 0) /* Interrupt type on timer1 timeout */ /* Reload register bits */ #define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */ /* Magic constants */ #define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */ #define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */ /* Device state. */ struct I6300State { PCIDevice dev; MemoryRegion io_mem; int reboot_enabled; /* "Reboot" on timer expiry. The real action * performed depends on the -watchdog-action * param passed on QEMU command line. */ int clock_scale; /* Clock scale. */ #define CLOCK_SCALE_1KHZ 0 #define CLOCK_SCALE_1MHZ 1 int int_type; /* Interrupt type generated. */ #define INT_TYPE_IRQ 0 /* APIC 1, INT 10 */ #define INT_TYPE_SMI 2 #define INT_TYPE_DISABLED 3 int free_run; /* If true, reload timer on expiry. */ int locked; /* If true, enabled field cannot be changed. */ int enabled; /* If true, watchdog is enabled. */ QEMUTimer *timer; /* The actual watchdog timer. */ uint32_t timer1_preload; /* Values preloaded into timer1, timer2. */ uint32_t timer2_preload; int stage; /* Stage (1 or 2). */ int unlock_state; /* Guest writes 0x80, 0x86 to unlock the * registers, and we transition through * states 0 -> 1 -> 2 when this happens. */ int previous_reboot_flag; /* If the watchdog caused the previous * reboot, this flag will be set. */ }; #define TYPE_WATCHDOG_I6300ESB_DEVICE "i6300esb" OBJECT_DECLARE_SIMPLE_TYPE(I6300State, WATCHDOG_I6300ESB_DEVICE) /* This function is called when the watchdog has either been enabled * (hence it starts counting down) or has been keep-alived. */ static void i6300esb_restart_timer(I6300State *d, int stage) { int64_t timeout; if (!d->enabled) return; d->stage = stage; if (d->stage <= 1) timeout = d->timer1_preload; else timeout = d->timer2_preload; if (d->clock_scale == CLOCK_SCALE_1KHZ) timeout <<= 15; else timeout <<= 5; /* Get the timeout in nanoseconds. */ timeout = timeout * 30; /* on a PCI bus, 1 tick is 30 ns*/ i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout); timer_mod(d->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout); } /* This is called when the guest disables the watchdog. */ static void i6300esb_disable_timer(I6300State *d) { i6300esb_debug("timer disabled\n"); timer_del(d->timer); } static void i6300esb_reset(DeviceState *dev) { PCIDevice *pdev = PCI_DEVICE(dev); I6300State *d = WATCHDOG_I6300ESB_DEVICE(pdev); i6300esb_debug("I6300State = %p\n", d); i6300esb_disable_timer(d); /* NB: Don't change d->previous_reboot_flag in this function. */ d->reboot_enabled = 1; d->clock_scale = CLOCK_SCALE_1KHZ; d->int_type = INT_TYPE_IRQ; d->free_run = 0; d->locked = 0; d->enabled = 0; d->timer1_preload = 0xfffff; d->timer2_preload = 0xfffff; d->stage = 1; d->unlock_state = 0; } /* This function is called when the watchdog expires. Note that * the hardware has two timers, and so expiry happens in two stages. * If d->stage == 1 then we perform the first stage action (usually, * sending an interrupt) and then restart the timer again for the * second stage. If the second stage expires then the watchdog * really has run out. */ static void i6300esb_timer_expired(void *vp) { I6300State *d = vp; i6300esb_debug("stage %d\n", d->stage); if (d->stage == 1) { /* What to do at the end of stage 1? */ switch (d->int_type) { case INT_TYPE_IRQ: fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n"); break; case INT_TYPE_SMI: fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n"); break; } /* Start the second stage. */ i6300esb_restart_timer(d, 2); } else { /* Second stage expired, reboot for real. */ if (d->reboot_enabled) { d->previous_reboot_flag = 1; watchdog_perform_action(); /* This reboots, exits, etc */ i6300esb_reset(DEVICE(d)); } /* In "free running mode" we start stage 1 again. */ if (d->free_run) i6300esb_restart_timer(d, 1); } } static void i6300esb_config_write(PCIDevice *dev, uint32_t addr, uint32_t data, int len) { I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); int old; i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len); if (addr == ESB_CONFIG_REG && len == 2) { d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0; d->clock_scale = (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ; d->int_type = (data & ESB_WDT_INTTYPE); } else if (addr == ESB_LOCK_REG && len == 1) { if (!d->locked) { d->locked = (data & ESB_WDT_LOCK) != 0; d->free_run = (data & ESB_WDT_FUNC) != 0; old = d->enabled; d->enabled = (data & ESB_WDT_ENABLE) != 0; if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */ i6300esb_restart_timer(d, 1); else if (!d->enabled) i6300esb_disable_timer(d); } } else { pci_default_write_config(dev, addr, data, len); } } static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len) { I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); uint32_t data; i6300esb_debug ("addr = %x, len = %d\n", addr, len); if (addr == ESB_CONFIG_REG && len == 2) { data = (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) | (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) | d->int_type; return data; } else if (addr == ESB_LOCK_REG && len == 1) { data = (d->free_run ? ESB_WDT_FUNC : 0) | (d->locked ? ESB_WDT_LOCK : 0) | (d->enabled ? ESB_WDT_ENABLE : 0); return data; } else { return pci_default_read_config(dev, addr, len); } } static uint32_t i6300esb_mem_readb(void *vp, hwaddr addr) { i6300esb_debug ("addr = %x\n", (int) addr); return 0; } static uint32_t i6300esb_mem_readw(void *vp, hwaddr addr) { uint32_t data = 0; I6300State *d = vp; i6300esb_debug("addr = %x\n", (int) addr); if (addr == 0xc) { /* The previous reboot flag is really bit 9, but there is * a bug in the Linux driver where it thinks it's bit 12. * Set both. */ data = d->previous_reboot_flag ? 0x1200 : 0; } return data; } static uint32_t i6300esb_mem_readl(void *vp, hwaddr addr) { i6300esb_debug("addr = %x\n", (int) addr); return 0; } static void i6300esb_mem_writeb(void *vp, hwaddr addr, uint32_t val) { I6300State *d = vp; i6300esb_debug("addr = %x, val = %x\n", (int) addr, val); if (addr == 0xc && val == 0x80) d->unlock_state = 1; else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) d->unlock_state = 2; } static void i6300esb_mem_writew(void *vp, hwaddr addr, uint32_t val) { I6300State *d = vp; i6300esb_debug("addr = %x, val = %x\n", (int) addr, val); if (addr == 0xc && val == 0x80) d->unlock_state = 1; else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) d->unlock_state = 2; else { if (d->unlock_state == 2) { if (addr == 0xc) { if ((val & 0x100) != 0) /* This is the "ping" from the userspace watchdog in * the guest ... */ i6300esb_restart_timer(d, 1); /* Setting bit 9 resets the previous reboot flag. * There's a bug in the Linux driver where it sets * bit 12 instead. */ if ((val & 0x200) != 0 || (val & 0x1000) != 0) { d->previous_reboot_flag = 0; } } d->unlock_state = 0; } } } static void i6300esb_mem_writel(void *vp, hwaddr addr, uint32_t val) { I6300State *d = vp; i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val); if (addr == 0xc && val == 0x80) d->unlock_state = 1; else if (addr == 0xc && val == 0x86 && d->unlock_state == 1) d->unlock_state = 2; else { if (d->unlock_state == 2) { if (addr == 0) d->timer1_preload = val & 0xfffff; else if (addr == 4) d->timer2_preload = val & 0xfffff; d->unlock_state = 0; } } } static uint64_t i6300esb_mem_readfn(void *opaque, hwaddr addr, unsigned size) { switch (size) { case 1: return i6300esb_mem_readb(opaque, addr); case 2: return i6300esb_mem_readw(opaque, addr); case 4: return i6300esb_mem_readl(opaque, addr); default: g_assert_not_reached(); } } static void i6300esb_mem_writefn(void *opaque, hwaddr addr, uint64_t value, unsigned size) { switch (size) { case 1: i6300esb_mem_writeb(opaque, addr, value); break; case 2: i6300esb_mem_writew(opaque, addr, value); break; case 4: i6300esb_mem_writel(opaque, addr, value); break; default: g_assert_not_reached(); } } static const MemoryRegionOps i6300esb_ops = { .read = i6300esb_mem_readfn, .write = i6300esb_mem_writefn, .valid.min_access_size = 1, .valid.max_access_size = 4, .endianness = DEVICE_LITTLE_ENDIAN, }; static const VMStateDescription vmstate_i6300esb = { .name = "i6300esb_wdt", /* With this VMSD's introduction, version_id/minimum_version_id were * erroneously set to sizeof(I6300State), causing a somewhat random * version_id to be set for every build. This eventually broke * migration. * * To correct this without breaking old->new migration for older * versions of QEMU, we've set version_id to a value high enough * to exceed all past values of sizeof(I6300State) across various * build environments, and have reset minimum_version_id to 1, * since this VMSD has never changed and thus can accept all past * versions. * * For future changes we can treat these values as we normally would. */ .version_id = 10000, .minimum_version_id = 1, .fields = (const VMStateField[]) { VMSTATE_PCI_DEVICE(dev, I6300State), VMSTATE_INT32(reboot_enabled, I6300State), VMSTATE_INT32(clock_scale, I6300State), VMSTATE_INT32(int_type, I6300State), VMSTATE_INT32(free_run, I6300State), VMSTATE_INT32(locked, I6300State), VMSTATE_INT32(enabled, I6300State), VMSTATE_TIMER_PTR(timer, I6300State), VMSTATE_UINT32(timer1_preload, I6300State), VMSTATE_UINT32(timer2_preload, I6300State), VMSTATE_INT32(stage, I6300State), VMSTATE_INT32(unlock_state, I6300State), VMSTATE_INT32(previous_reboot_flag, I6300State), VMSTATE_END_OF_LIST() } }; static void i6300esb_realize(PCIDevice *dev, Error **errp) { I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); i6300esb_debug("I6300State = %p\n", d); d->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, i6300esb_timer_expired, d); d->previous_reboot_flag = 0; memory_region_init_io(&d->io_mem, OBJECT(d), &i6300esb_ops, d, "i6300esb", 0x10); pci_register_bar(&d->dev, 0, 0, &d->io_mem); } static void i6300esb_exit(PCIDevice *dev) { I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev); timer_free(d->timer); } static void i6300esb_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); PCIDeviceClass *k = PCI_DEVICE_CLASS(klass); k->config_read = i6300esb_config_read; k->config_write = i6300esb_config_write; k->realize = i6300esb_realize; k->exit = i6300esb_exit; k->vendor_id = PCI_VENDOR_ID_INTEL; k->device_id = PCI_DEVICE_ID_INTEL_ESB_9; k->class_id = PCI_CLASS_SYSTEM_OTHER; device_class_set_legacy_reset(dc, i6300esb_reset); dc->vmsd = &vmstate_i6300esb; set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories); dc->desc = "Intel 6300ESB"; } static const TypeInfo i6300esb_info = { .name = TYPE_WATCHDOG_I6300ESB_DEVICE, .parent = TYPE_PCI_DEVICE, .instance_size = sizeof(I6300State), .class_init = i6300esb_class_init, .interfaces = (InterfaceInfo[]) { { INTERFACE_CONVENTIONAL_PCI_DEVICE }, { }, }, }; static void i6300esb_register_types(void) { type_register_static(&i6300esb_info); } type_init(i6300esb_register_types)