Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 125 insertions, 0 deletions

diff --git a/arch/mips/kernel/reset.c b/arch/mips/kernel/reset.c
new file mode 100644
index 000000000..6288780b7
--- /dev/null
+++ b/arch/mips/kernel/reset.c
@@ -0,0 +1,125 @@
+/*
+ * 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)
+{
+	if (pm_power_off)
+		pm_power_off();
+
+#ifdef CONFIG_SMP
+	preempt_disable();
+	smp_send_stop();
+#endif
+	machine_hang();
+}