manage.c revision c5cae661d6cf808b6984762f763261adf35f3eb7
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); 46770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki return err; 47770824bdc421ff58a64db608294323571c949f4cRafael J. Wysocki } 48359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge 490e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_mm_pin_all(); 500e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge gnttab_suspend(); 510e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_pre_suspend(); 520e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 530e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge /* 540e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * This hypercall returns 1 if suspend was cancelled 550e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * or the domain was merely checkpointed, and 0 if it 560e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge * is resuming in a new domain. 570e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge */ 580e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); 590e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 600e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_post_suspend(*cancelled); 610e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge gnttab_resume(); 620e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_mm_unpin_all(); 630e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 640e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (!*cancelled) { 650e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_irq_resume(); 660e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge xen_console_resume(); 67ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata xen_timer_resume(); 680e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 690e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 701e6fcf840e11ceff8a656a678c6e4b0560a98e08Ian Campbell sysdev_resume(); 711e6fcf840e11ceff8a656a678c6e4b0560a98e08Ian Campbell 720e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge return 0; 730e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge} 740e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 750e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardingestatic void do_suspend(void) 760e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge{ 770e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge int err; 780e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge int cancelled = 1; 790e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 800e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_SUSPEND; 810e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 82b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell err = stop_machine_create(); 83b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell if (err) { 84b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err); 85b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell goto out; 86b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell } 87b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell 880e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PREEMPT 890e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge /* If the kernel is preemptible, we need to freeze all the processes 900e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge to prevent them from being in the middle of a pagetable update 910e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge during suspend. */ 920e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge err = freeze_processes(); 930e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 940e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge printk(KERN_ERR "xen suspend: freeze failed %d\n", err); 95b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell goto out_destroy_sm; 960e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 970e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 980e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 99d161630297a20802d01c55847bfcba85d2118a9fAlan Stern err = dpm_suspend_start(PMSG_SUSPEND); 1000e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 101d161630297a20802d01c55847bfcba85d2118a9fAlan Stern printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err); 10265f63384b391bf4d384327d8a7c6de9860290b5cIan Campbell goto out_thaw; 1030e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 1040e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 105c5cae661d6cf808b6984762f763261adf35f3eb7Ian Campbell printk(KERN_DEBUG "suspending xenstore...\n"); 106c5cae661d6cf808b6984762f763261adf35f3eb7Ian Campbell xs_suspend(); 107c5cae661d6cf808b6984762f763261adf35f3eb7Ian Campbell 108d161630297a20802d01c55847bfcba85d2118a9fAlan Stern err = dpm_suspend_noirq(PMSG_SUSPEND); 1092ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki if (err) { 110d161630297a20802d01c55847bfcba85d2118a9fAlan Stern printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err); 11165f63384b391bf4d384327d8a7c6de9860290b5cIan Campbell goto out_resume; 1122ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki } 1132ed8d2b3a81bdbb0418301628ccdb008ac9f40b7Rafael J. Wysocki 114f7df8ed164996cd2c6aca9674388be6ef78d8b37Rusty Russell err = stop_machine(xen_suspend, &cancelled, cpumask_of(0)); 115922cc38ab71d1360978e65207e4a4f4988987127Jeremy Fitzhardinge 116922cc38ab71d1360978e65207e4a4f4988987127Jeremy Fitzhardinge dpm_resume_noirq(PMSG_RESUME); 117922cc38ab71d1360978e65207e4a4f4988987127Jeremy Fitzhardinge 1180e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge if (err) { 1190e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge printk(KERN_ERR "failed to start xen_suspend: %d\n", err); 12065f63384b391bf4d384327d8a7c6de9860290b5cIan Campbell cancelled = 1; 1210e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } 1220e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 123c5cae661d6cf808b6984762f763261adf35f3eb7Ian Campbellout_resume: 124ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata if (!cancelled) { 125ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata xen_arch_resume(); 126de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell xs_resume(); 127ad55db9fed6d6cd09333045945cb03ba2c070085Isaku Yamahata } else 128de5b31bd47de7e6f41be2e271318dbc8f1af354dIan Campbell xs_suspend_cancel(); 1290e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 130d161630297a20802d01c55847bfcba85d2118a9fAlan Stern dpm_resume_end(PMSG_RESUME); 1310e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge 132359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge /* Make sure timer events get retriggered on all CPUs */ 133359cdd3f866b6219a6729e313faf2221397f3278Jeremy Fitzhardinge clock_was_set(); 13465f63384b391bf4d384327d8a7c6de9860290b5cIan Campbell 13565f63384b391bf4d384327d8a7c6de9860290b5cIan Campbellout_thaw: 1360e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PREEMPT 1370e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge thaw_processes(); 138b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell 139b4606f2165153833247823e8c04c5e88cb3d298bIan Campbellout_destroy_sm: 1400e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 141b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell stop_machine_destroy(); 142b4606f2165153833247823e8c04c5e88cb3d298bIan Campbell 14365f63384b391bf4d384327d8a7c6de9860290b5cIan Campbellout: 1440e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_INVALID; 1450e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge} 146c78277288e3d561d55fb48bc0fe8d6e2cf4d0880Jeremy Fitzhardinge#endif /* CONFIG_PM_SLEEP */ 1473e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1483e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic void shutdown_handler(struct xenbus_watch *watch, 1493e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge const char **vec, unsigned int len) 1503e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 1513e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge char *str; 1523e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge struct xenbus_transaction xbt; 1533e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 1543e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1553e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (shutting_down != SHUTDOWN_INVALID) 1563e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1573e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1583e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge again: 1593e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_start(&xbt); 1603e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) 1613e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1623e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1633e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); 1643e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge /* Ignore read errors and empty reads. */ 1653e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (XENBUS_IS_ERR_READ(str)) { 1663e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_transaction_end(xbt, 1); 1673e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 1683e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1693e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1703e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_write(xbt, "control", "shutdown", ""); 1713e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1723e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_end(xbt, 0); 1733e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err == -EAGAIN) { 1743e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge kfree(str); 1753e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge goto again; 1763e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1773e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1783e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (strcmp(str, "poweroff") == 0 || 1790e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge strcmp(str, "halt") == 0) { 1800e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_POWEROFF; 1813e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge orderly_poweroff(false); 1820e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else if (strcmp(str, "reboot") == 0) { 1830e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge shutting_down = SHUTDOWN_POWEROFF; /* ? */ 1843e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge ctrl_alt_del(); 1850e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#ifdef CONFIG_PM_SLEEP 1860e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else if (strcmp(str, "suspend") == 0) { 1870e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge do_suspend(); 1880e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge#endif 1890e91398f2a5d4eb6b07df8115917d0d1cf3e9b58Jeremy Fitzhardinge } else { 1903e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_INFO "Ignoring shutdown request: %s\n", str); 1913e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge shutting_down = SHUTDOWN_INVALID; 1923e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 1933e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1943e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge kfree(str); 1953e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 1963e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 1973e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic void sysrq_handler(struct xenbus_watch *watch, const char **vec, 1983e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge unsigned int len) 1993e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2003e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge char sysrq_key = '\0'; 2013e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge struct xenbus_transaction xbt; 2023e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 2033e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2043e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge again: 2053e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_start(&xbt); 2063e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) 2073e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 2083e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { 2093e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Unable to read sysrq code in " 2103e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge "control/sysrq\n"); 2113e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_transaction_end(xbt, 1); 2123e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return; 2133e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2143e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2153e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (sysrq_key != '\0') 2163e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); 2173e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2183e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = xenbus_transaction_end(xbt, 0); 2193e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err == -EAGAIN) 2203e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge goto again; 2213e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2223e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (sysrq_key != '\0') 2233e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge handle_sysrq(sysrq_key, NULL); 2243e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2253e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2263e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic struct xenbus_watch shutdown_watch = { 2273e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .node = "control/shutdown", 2283e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .callback = shutdown_handler 2293e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge}; 2303e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2313e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic struct xenbus_watch sysrq_watch = { 2323e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .node = "control/sysrq", 2333e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .callback = sysrq_handler 2343e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge}; 2353e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2363e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int setup_shutdown_watcher(void) 2373e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2383e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge int err; 2393e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2403e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = register_xenbus_watch(&shutdown_watch); 2413e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) { 2423e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Failed to set shutdown watcher\n"); 2433e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return err; 2443e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2453e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2463e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge err = register_xenbus_watch(&sysrq_watch); 2473e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge if (err) { 2483e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge printk(KERN_ERR "Failed to set sysrq watcher\n"); 2493e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return err; 2503e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge } 2513e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2523e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return 0; 2533e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2543e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2553e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int shutdown_event(struct notifier_block *notifier, 2563e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge unsigned long event, 2573e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge void *data) 2583e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2593e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge setup_shutdown_watcher(); 2603e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return NOTIFY_DONE; 2613e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2623e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2633e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingestatic int __init setup_shutdown_event(void) 2643e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge{ 2653e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge static struct notifier_block xenstore_notifier = { 2663e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge .notifier_call = shutdown_event 2673e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge }; 2683e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge register_xenstore_notifier(&xenstore_notifier); 2693e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2703e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge return 0; 2713e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge} 2723e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardinge 2733e2b8fbeec8f005672f2a2e862fb9c26a0bafedcJeremy Fitzhardingesubsys_initcall(setup_shutdown_event); 274