v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/leon_pmc.c b/arch/sparc/kernel/leon_pmc.c
new file mode 100644
index 0000000..065e2d4
--- /dev/null
+++ b/arch/sparc/kernel/leon_pmc.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/* leon_pmc.c: LEON Power-down cpu_idle() handler
+ *
+ * Copyright (C) 2011 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
+ */
+
+#include <linux/init.h>
+#include <linux/pm.h>
+
+#include <asm/leon_amba.h>
+#include <asm/cpu_type.h>
+#include <asm/leon.h>
+#include <asm/processor.h>
+
+/* List of Systems that need fixup instructions around power-down instruction */
+static unsigned int pmc_leon_fixup_ids[] = {
+ AEROFLEX_UT699,
+ GAISLER_GR712RC,
+ LEON4_NEXTREME1,
+ 0
+};
+
+static int pmc_leon_need_fixup(void)
+{
+ unsigned int systemid = amba_system_id >> 16;
+ unsigned int *id;
+
+ id = &pmc_leon_fixup_ids[0];
+ while (*id != 0) {
+ if (*id == systemid)
+ return 1;
+ id++;
+ }
+
+ return 0;
+}
+
+/*
+ * CPU idle callback function for systems that need some extra handling
+ * See .../arch/sparc/kernel/process.c
+ */
+static void pmc_leon_idle_fixup(void)
+{
+ /* Prepare an address to a non-cachable region. APB is always
+ * none-cachable. One instruction is executed after the Sleep
+ * instruction, we make sure to read the bus and throw away the
+ * value by accessing a non-cachable area, also we make sure the
+ * MMU does not get a TLB miss here by using the MMU BYPASS ASI.
+ */
+ register unsigned int address = (unsigned int)leon3_irqctrl_regs;
+
+ /* Interrupts need to be enabled to not hang the CPU */
+ local_irq_enable();
+
+ __asm__ __volatile__ (
+ "wr %%g0, %%asr19\n"
+ "lda [%0] %1, %%g0\n"
+ :
+ : "r"(address), "i"(ASI_LEON_BYPASS));
+}
+
+/*
+ * CPU idle callback function
+ * See .../arch/sparc/kernel/process.c
+ */
+static void pmc_leon_idle(void)
+{
+ /* Interrupts need to be enabled to not hang the CPU */
+ local_irq_enable();
+
+ /* For systems without power-down, this will be no-op */
+ __asm__ __volatile__ ("wr %g0, %asr19\n\t");
+}
+
+/* Install LEON Power Down function */
+static int __init leon_pmc_install(void)
+{
+ if (sparc_cpu_model == sparc_leon) {
+ /* Assign power management IDLE handler */
+ if (pmc_leon_need_fixup())
+ sparc_idle = pmc_leon_idle_fixup;
+ else
+ sparc_idle = pmc_leon_idle;
+
+ printk(KERN_INFO "leon: power management initialized\n");
+ }
+
+ return 0;
+}
+
+/* This driver is not critical to the boot process, don't care
+ * if initialized late.
+ */
+late_initcall(leon_pmc_install);