Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Handle extern requests for shutdown, reboot and sysrq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/reboot.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/sysrq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/stop_machine.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/freezer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/syscore_ops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <xen/xen.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <xen/xenbus.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <xen/grant_table.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <xen/events.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <xen/hvc-console.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <xen/page.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <xen/xen-ops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <asm/xen/hypercall.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <asm/xen/hypervisor.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) enum shutdown_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	SHUTDOWN_INVALID = -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	SHUTDOWN_POWEROFF = 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	SHUTDOWN_SUSPEND = 2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	/* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	   report a crash, not be instructed to crash!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	   HALT is the same as POWEROFF, as far as we're concerned.  The tools use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	   the distinction when we return the reason code to them.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	 SHUTDOWN_HALT = 4,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) /* Ignore multiple shutdown requests. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) struct suspend_info {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	int cancelled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static RAW_NOTIFIER_HEAD(xen_resume_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) void xen_resume_notifier_register(struct notifier_block *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	raw_notifier_chain_register(&xen_resume_notifier, nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) EXPORT_SYMBOL_GPL(xen_resume_notifier_register);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) void xen_resume_notifier_unregister(struct notifier_block *nb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	raw_notifier_chain_unregister(&xen_resume_notifier, nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) #ifdef CONFIG_HIBERNATE_CALLBACKS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) static int xen_suspend(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	struct suspend_info *si = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	BUG_ON(!irqs_disabled());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	err = syscore_suspend();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		pr_err("%s: system core suspend failed: %d\n", __func__, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	gnttab_suspend();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	xen_manage_runstate_time(-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	xen_arch_pre_suspend();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	si->cancelled = HYPERVISOR_suspend(xen_pv_domain()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80)                                            ? virt_to_gfn(xen_start_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81)                                            : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	xen_arch_post_suspend(si->cancelled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	xen_manage_runstate_time(si->cancelled ? 1 : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	gnttab_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	if (!si->cancelled) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		xen_irq_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		xen_timer_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	syscore_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) static void do_suspend(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	struct suspend_info si;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	shutting_down = SHUTDOWN_SUSPEND;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	err = freeze_processes();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		pr_err("%s: freeze processes failed %d\n", __func__, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	err = freeze_kernel_threads();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		pr_err("%s: freeze kernel threads failed %d\n", __func__, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		goto out_thaw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	err = dpm_suspend_start(PMSG_FREEZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		pr_err("%s: dpm_suspend_start %d\n", __func__, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		goto out_thaw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	printk(KERN_DEBUG "suspending xenstore...\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	xs_suspend();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	err = dpm_suspend_end(PMSG_FREEZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		pr_err("dpm_suspend_end failed: %d\n", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		si.cancelled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		goto out_resume;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	xen_arch_suspend();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	si.cancelled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	err = stop_machine(xen_suspend, &si, cpumask_of(0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	/* Resume console as early as possible. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	if (!si.cancelled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		xen_console_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		pr_err("failed to start xen_suspend: %d\n", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		si.cancelled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	xen_arch_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) out_resume:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	if (!si.cancelled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 		xs_resume();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 		xs_suspend_cancel();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) out_thaw:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	thaw_processes();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	shutting_down = SHUTDOWN_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #endif	/* CONFIG_HIBERNATE_CALLBACKS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) struct shutdown_handler {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) #define SHUTDOWN_CMD_SIZE 11
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	const char command[SHUTDOWN_CMD_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	bool flag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	void (*cb)(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	switch (code) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	case SYS_DOWN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	case SYS_HALT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	case SYS_POWER_OFF:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		shutting_down = SHUTDOWN_POWEROFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static void do_poweroff(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	switch (system_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	case SYSTEM_BOOTING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	case SYSTEM_SCHEDULING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		orderly_poweroff(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	case SYSTEM_RUNNING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		orderly_poweroff(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		/* Don't do it when we are halting/rebooting. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		pr_info("Ignoring Xen toolstack shutdown.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static void do_reboot(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	shutting_down = SHUTDOWN_POWEROFF; /* ? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	ctrl_alt_del();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) static struct shutdown_handler shutdown_handlers[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	{ "poweroff",	true,	do_poweroff },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	{ "halt",	false,	do_poweroff },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	{ "reboot",	true,	do_reboot   },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) #ifdef CONFIG_HIBERNATE_CALLBACKS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	{ "suspend",	true,	do_suspend  },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static void shutdown_handler(struct xenbus_watch *watch,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 			     const char *path, const char *token)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	char *str;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	struct xenbus_transaction xbt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (shutting_down != SHUTDOWN_INVALID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)  again:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	err = xenbus_transaction_start(&xbt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	str = (char *)xenbus_read(xbt, "control", "shutdown", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	/* Ignore read errors and empty reads. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	if (XENBUS_IS_ERR_READ(str)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		xenbus_transaction_end(xbt, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		if (strcmp(str, shutdown_handlers[idx].command) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	/* Only acknowledge commands which we are prepared to handle. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	if (idx < ARRAY_SIZE(shutdown_handlers))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 		xenbus_write(xbt, "control", "shutdown", "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	err = xenbus_transaction_end(xbt, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	if (err == -EAGAIN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		kfree(str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		goto again;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	if (idx < ARRAY_SIZE(shutdown_handlers)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		shutdown_handlers[idx].cb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 		pr_info("Ignoring shutdown request: %s\n", str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 		shutting_down = SHUTDOWN_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	kfree(str);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) #ifdef CONFIG_MAGIC_SYSRQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) static void sysrq_handler(struct xenbus_watch *watch, const char *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 			  const char *token)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	char sysrq_key = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	struct xenbus_transaction xbt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)  again:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	err = xenbus_transaction_start(&xbt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		 * The Xenstore watch fires directly after registering it and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		 * after a suspend/resume cycle. So ENOENT is no error but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		 * might happen in those cases. ERANGE is observed when we get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		 * an empty value (''), this happens when we acknowledge the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 		 * request by writing '\0' below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		if (err != -ENOENT && err != -ERANGE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 			pr_err("Error %d reading sysrq code in control/sysrq\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 			       err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		xenbus_transaction_end(xbt, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	if (sysrq_key != '\0') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 		err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 			pr_err("%s: Error %d writing sysrq in control/sysrq\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 			       __func__, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 			xenbus_transaction_end(xbt, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	err = xenbus_transaction_end(xbt, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	if (err == -EAGAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 		goto again;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	if (sysrq_key != '\0')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 		handle_sysrq(sysrq_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) static struct xenbus_watch sysrq_watch = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 	.node = "control/sysrq",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 	.callback = sysrq_handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) static struct xenbus_watch shutdown_watch = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 	.node = "control/shutdown",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	.callback = shutdown_handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) static struct notifier_block xen_reboot_nb = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	.notifier_call = poweroff_nb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) static int setup_shutdown_watcher(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	int idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) #define FEATURE_PATH_SIZE (SHUTDOWN_CMD_SIZE + sizeof("feature-"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	char node[FEATURE_PATH_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	err = register_xenbus_watch(&shutdown_watch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 		pr_err("Failed to set shutdown watcher\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) #ifdef CONFIG_MAGIC_SYSRQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	err = register_xenbus_watch(&sysrq_watch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		pr_err("Failed to set sysrq watcher\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	for (idx = 0; idx < ARRAY_SIZE(shutdown_handlers); idx++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 		if (!shutdown_handlers[idx].flag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 		snprintf(node, FEATURE_PATH_SIZE, "feature-%s",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 			 shutdown_handlers[idx].command);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 		err = xenbus_printf(XBT_NIL, "control", node, "%u", 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 		if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 			pr_err("%s: Error %d writing %s\n", __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 				err, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 			return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) static int shutdown_event(struct notifier_block *notifier,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 			  unsigned long event,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 			  void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 	setup_shutdown_watcher();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) int xen_setup_shutdown_event(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 	static struct notifier_block xenstore_notifier = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 		.notifier_call = shutdown_event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 	if (!xen_domain())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	register_xenstore_notifier(&xenstore_notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 	register_reboot_notifier(&xen_reboot_nb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) EXPORT_SYMBOL_GPL(xen_setup_shutdown_event);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) subsys_initcall(xen_setup_shutdown_event);