manage.c revision d161630297a20802d01c55847bfcba85d2118a9f
13e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge/* 23e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge * Handle extern requests for shutdown, reboot and sysrq 33e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge */ 43e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge#include <linux/kernel.h> 53e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge#include <linux/err.h> 63e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge#include <linux/reboot.h> 73e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge#include <linux/sysrq.h> 80e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <linux/stop_machine.h> 90e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <linux/freezer.h> 103e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 113e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge#include <xen/xenbus.h> 120e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <xen/grant_table.h> 130e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <xen/events.h> 140e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <xen/hvc-console.h> 150e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <xen/xen-ops.h> 163e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 170e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <asm/xen/hypercall.h> 180e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#include <asm/xen/page.h> 190e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 200e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingeenum shutdown_state { 210e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge SHUTDOWN_INVALID = -1, 220e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge SHUTDOWN_POWEROFF = 0, 230e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge SHUTDOWN_SUSPEND = 2, 240e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge /* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only 250e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge report a crash, not be instructed to crash! 260e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge HALT is the same as POWEROFF, as far as we're concerned. The tools use 270e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge the distinction when we return the reason code to them. */ 280e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge SHUTDOWN_HALT = 4, 290e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge}; 303e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 313e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge/* Ignore multiple shutdown requests. */ 320e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingestatic enum shutdown_state shutting_down = SHUTDOWN_INVALID; 330e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 34c78277288e3d561d55fb48bc0fe8d6e2cf4d0880Jeremy Fitzhardinge#ifdef CONFIG_PM_SLEEP 350e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingestatic int xen_suspend(void *data) 360e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge{ 370e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge int *cancelled = data; 38359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge int err; 390e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 400e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge BUG_ON(!irqs_disabled()); 410e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 42770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki err = sysdev_suspend(PMSG_SUSPEND); 43770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki if (err) { 44770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n", 45770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki err); 46d161630297a20802d01c55847bfcba85d2118a9fAlan Stern dpm_resume_noirq(PMSG_RESUME); 47770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki return err; 48770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki } 49359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge 500e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_mm_pin_all(); 510e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge gnttab_suspend(); 520e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_pre_suspend(); 530e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 540e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge /* 550e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * This hypercall returns 1 if suspend was cancelled 560e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * or the domain was merely checkpointed, and 0 if it 570e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * is resuming in a new domain. 580e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge */ 590e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); 600e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 610e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_post_suspend(*cancelled); 620e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge gnttab_resume(); 630e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_mm_unpin_all(); 640e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 650e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (!*cancelled) { 660e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_irq_resume(); 670e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_console_resume(); 68ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata xen_timer_resume(); 690e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 700e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 711e6fcf840e11ceff8a656a678c6e4b0560a98e08Ian Campbell sysdev_resume(); 72d161630297a20802d01c55847bfcba85d2118a9fAlan Stern dpm_resume_noirq(PMSG_RESUME); 731e6fcf840e11ceff8a656a678c6e4b0560a98e08Ian Campbell 740e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge return 0; 750e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge} 760e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 770e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingestatic void do_suspend(void) 780e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge{ 790e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge int err; 800e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge int cancelled = 1; 810e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 820e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_SUSPEND; 830e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 840e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PREEMPT 850e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge /* If the kernel is preemptible, we need to freeze all the processes 860e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge to prevent them from being in the middle of a pagetable update 870e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge during suspend. */ 880e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge err = freeze_processes(); 890e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 900e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge printk(KERN_ERR "xen suspend: freeze failed %d\n", err); 910e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge return; 920e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 930e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 940e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 95d161630297a20802d01c55847bfcba85d2118a9fAlan Stern err = dpm_suspend_start(PMSG_SUSPEND); 960e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 97d161630297a20802d01c55847bfcba85d2118a9fAlan Stern printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); 980e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge goto out; 990e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 1000e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 101de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell printk(KERN_DEBUG "suspending xenstore...\n"); 102de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell xs_suspend(); 1030e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 104d161630297a20802d01c55847bfcba85d2118a9fAlan Stern err = dpm_suspend_noirq(PMSG_SUSPEND); 1052ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki if (err) { 106d161630297a20802d01c55847bfcba85d2118a9fAlan Stern printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); 1072ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki goto resume_devices; 1082ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki } 1092ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki 110f7df8ed164996cd2c6aca9674388be6ef78d8b37Rusty Russell err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); 1110e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 1120e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge printk(KERN_ERR "failed to start xen_suspend: %d\n", err); 1130e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge goto out; 1140e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 1150e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 116ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata if (!cancelled) { 117ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata xen_arch_resume(); 118de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell xs_resume(); 119ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata } else 120de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell xs_suspend_cancel(); 1210e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 122d161630297a20802d01c55847bfcba85d2118a9fAlan Stern dpm_resume_noirq(PMSG_RESUME); 1232ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki 1242ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysockiresume_devices: 125d161630297a20802d01c55847bfcba85d2118a9fAlan Stern dpm_resume_end(PMSG_RESUME); 1260e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 127359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge /* Make sure timer events get retriggered on all CPUs */ 128359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge clock_was_set(); 1290e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingeout: 1300e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PREEMPT 1310e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge thaw_processes(); 1320e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 1330e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_INVALID; 1340e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge} 135c78277288e3d561d55fb48bc0fe8d6e2cf4d0880Jeremy Fitzhardinge#endif /* CONFIG_PM_SLEEP */ 1363e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1373e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic void shutdown_handler(struct xenbus_watch *watch, 1383e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge const char **vec, unsigned int len) 1393e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 1403e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge char *str; 1413e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge struct xenbus_transaction xbt; 1423e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 1433e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1443e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (shutting_down != SHUTDOWN_INVALID) 1453e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1463e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1473e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge again: 1483e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_start(&xbt); 1493e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) 1503e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1513e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1523e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); 1533e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge /* Ignore read errors and empty reads. */ 1543e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (XENBUS_IS_ERR_READ(str)) { 1553e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_transaction_end(xbt, 1); 1563e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1573e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1583e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1593e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_write(xbt, "control", "shutdown", ""); 1603e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1613e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_end(xbt, 0); 1623e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err == -EAGAIN) { 1633e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge kfree(str); 1643e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge goto again; 1653e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1663e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1673e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (strcmp(str, "poweroff") == 0 || 1680e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge strcmp(str, "halt") == 0) { 1690e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_POWEROFF; 1703e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge orderly_poweroff(false); 1710e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else if (strcmp(str, "reboot") == 0) { 1720e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_POWEROFF; /* ? */ 1733e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge ctrl_alt_del(); 1740e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PM_SLEEP 1750e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else if (strcmp(str, "suspend") == 0) { 1760e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge do_suspend(); 1770e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 1780e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else { 1793e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_INFO "Ignoring shutdown request: %s\n", str); 1803e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge shutting_down = SHUTDOWN_INVALID; 1813e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1823e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1833e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge kfree(str); 1843e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 1853e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1863e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic void sysrq_handler(struct xenbus_watch *watch, const char **vec, 1873e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge unsigned int len) 1883e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 1893e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge char sysrq_key = '\0'; 1903e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge struct xenbus_transaction xbt; 1913e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 1923e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1933e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge again: 1943e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_start(&xbt); 1953e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) 1963e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1973e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { 1983e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Unable to read sysrq code in " 1993e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge "control/sysrq\n"); 2003e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_transaction_end(xbt, 1); 2013e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 2023e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2033e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2043e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (sysrq_key != '\0') 2053e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); 2063e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2073e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_end(xbt, 0); 2083e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err == -EAGAIN) 2093e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge goto again; 2103e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2113e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (sysrq_key != '\0') 2123e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge handle_sysrq(sysrq_key, NULL); 2133e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2143e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2153e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic struct xenbus_watch shutdown_watch = { 2163e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .node = "control/shutdown", 2173e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .callback = shutdown_handler 2183e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge}; 2193e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2203e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic struct xenbus_watch sysrq_watch = { 2213e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .node = "control/sysrq", 2223e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .callback = sysrq_handler 2233e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge}; 2243e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2253e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int setup_shutdown_watcher(void) 2263e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2273e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 2283e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2293e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = register_xenbus_watch(&shutdown_watch); 2303e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) { 2313e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Failed to set shutdown watcher\n"); 2323e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return err; 2333e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2343e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2353e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = register_xenbus_watch(&sysrq_watch); 2363e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) { 2373e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Failed to set sysrq watcher\n"); 2383e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return err; 2393e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2403e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2413e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return 0; 2423e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2433e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2443e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int shutdown_event(struct notifier_block *notifier, 2453e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge unsigned long event, 2463e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge void *data) 2473e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2483e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge setup_shutdown_watcher(); 2493e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return NOTIFY_DONE; 2503e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2513e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2523e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int __init setup_shutdown_event(void) 2533e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2543e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge static struct notifier_block xenstore_notifier = { 2553e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .notifier_call = shutdown_event 2563e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge }; 2573e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge register_xenstore_notifier(&xenstore_notifier); 2583e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2593e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return 0; 2603e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2613e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2623e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingesubsys_initcall(setup_shutdown_event); 263