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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/mips/kernel/reset.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/kernel/reset.c')
-rw-r--r--arch/mips/kernel/reset.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/mips/kernel/reset.c b/arch/mips/kernel/reset.c
new file mode 100644
index 0000000000..e7ce07b3e7
--- /dev/null
+++ b/arch/mips/kernel/reset.c
@@ -0,0 +1,124 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001, 06 by Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2001 MIPS Technologies, Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/pm.h>
+#include <linux/types.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+
+#include <asm/compiler.h>
+#include <asm/idle.h>
+#include <asm/mipsregs.h>
+#include <asm/reboot.h>
+
+/*
+ * Urgs ... Too many MIPS machines to handle this in a generic way.
+ * So handle all using function pointers to machine specific
+ * functions.
+ */
+void (*_machine_restart)(char *command);
+void (*_machine_halt)(void);
+void (*pm_power_off)(void);
+
+EXPORT_SYMBOL(pm_power_off);
+
+static void machine_hang(void)
+{
+ /*
+ * We're hanging the system so we don't want to be interrupted anymore.
+ * Any interrupt handlers that ran would at best be useless & at worst
+ * go awry because the system isn't in a functional state.
+ */
+ local_irq_disable();
+
+ /*
+ * Mask all interrupts, giving us a better chance of remaining in the
+ * low power wait state.
+ */
+ clear_c0_status(ST0_IM);
+
+ while (true) {
+ if (cpu_has_mips_r) {
+ /*
+ * We know that the wait instruction is supported so
+ * make use of it directly, leaving interrupts
+ * disabled.
+ */
+ asm volatile(
+ ".set push\n\t"
+ ".set " MIPS_ISA_ARCH_LEVEL "\n\t"
+ "wait\n\t"
+ ".set pop");
+ } else if (cpu_wait) {
+ /*
+ * Try the cpu_wait() callback. This isn't ideal since
+ * it'll re-enable interrupts, but that ought to be
+ * harmless given that they're all masked.
+ */
+ cpu_wait();
+ local_irq_disable();
+ } else {
+ /*
+ * We're going to burn some power running round the
+ * loop, but we don't really have a choice. This isn't
+ * a path we should expect to run for long during
+ * typical use anyway.
+ */
+ }
+
+ /*
+ * In most modern MIPS CPUs interrupts will cause the wait
+ * instruction to graduate even when disabled, and in some
+ * cases even when masked. In order to prevent a timer
+ * interrupt from continuously taking us out of the low power
+ * wait state, we clear any pending timer interrupt here.
+ */
+ if (cpu_has_counter)
+ write_c0_compare(0);
+ }
+}
+
+void machine_restart(char *command)
+{
+ if (_machine_restart)
+ _machine_restart(command);
+
+#ifdef CONFIG_SMP
+ preempt_disable();
+ smp_send_stop();
+#endif
+ do_kernel_restart(command);
+ mdelay(1000);
+ pr_emerg("Reboot failed -- System halted\n");
+ machine_hang();
+}
+
+void machine_halt(void)
+{
+ if (_machine_halt)
+ _machine_halt();
+
+#ifdef CONFIG_SMP
+ preempt_disable();
+ smp_send_stop();
+#endif
+ machine_hang();
+}
+
+void machine_power_off(void)
+{
+ do_kernel_power_off();
+
+#ifdef CONFIG_SMP
+ preempt_disable();
+ smp_send_stop();
+#endif
+ machine_hang();
+}