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-rw-r--r--arch/arm/mach-shmobile/platsmp-apmu.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c b/arch/arm/mach-shmobile/platsmp-apmu.c
new file mode 100644
index 00000000000..1da5a72d964
--- /dev/null
+++ b/arch/arm/mach-shmobile/platsmp-apmu.c
@@ -0,0 +1,195 @@
+/*
+ * SMP support for SoCs with APMU
+ *
+ * Copyright (C) 2013 Magnus Damm
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/of_address.h>
+#include <linux/smp.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_plat.h>
+#include <mach/common.h>
+
+static struct {
+ void __iomem *iomem;
+ int bit;
+} apmu_cpus[CONFIG_NR_CPUS];
+
+#define WUPCR_OFFS 0x10
+#define PSTR_OFFS 0x40
+#define CPUNCR_OFFS(n) (0x100 + (0x10 * (n)))
+
+static int apmu_power_on(void __iomem *p, int bit)
+{
+ /* request power on */
+ writel_relaxed(BIT(bit), p + WUPCR_OFFS);
+
+ /* wait for APMU to finish */
+ while (readl_relaxed(p + WUPCR_OFFS) != 0)
+ ;
+
+ return 0;
+}
+
+static int apmu_power_off(void __iomem *p, int bit)
+{
+ /* request Core Standby for next WFI */
+ writel_relaxed(3, p + CPUNCR_OFFS(bit));
+ return 0;
+}
+
+static int apmu_power_off_poll(void __iomem *p, int bit)
+{
+ int k;
+
+ for (k = 0; k < 1000; k++) {
+ if (((readl_relaxed(p + PSTR_OFFS) >> (bit * 4)) & 0x03) == 3)
+ return 1;
+
+ mdelay(1);
+ }
+
+ return 0;
+}
+
+static int apmu_wrap(int cpu, int (*fn)(void __iomem *p, int cpu))
+{
+ void __iomem *p = apmu_cpus[cpu].iomem;
+
+ return p ? fn(p, apmu_cpus[cpu].bit) : -EINVAL;
+}
+
+static void apmu_init_cpu(struct resource *res, int cpu, int bit)
+{
+ if (apmu_cpus[cpu].iomem)
+ return;
+
+ apmu_cpus[cpu].iomem = ioremap_nocache(res->start, resource_size(res));
+ apmu_cpus[cpu].bit = bit;
+
+ pr_debug("apmu ioremap %d %d 0x%08x 0x%08x\n", cpu, bit,
+ res->start, resource_size(res));
+}
+
+static struct {
+ struct resource iomem;
+ int cpus[4];
+} apmu_config[] = {
+ {
+ .iomem = DEFINE_RES_MEM(0xe6152000, 0x88),
+ .cpus = { 0, 1, 2, 3 },
+ },
+ {
+ .iomem = DEFINE_RES_MEM(0xe6151000, 0x88),
+ .cpus = { 0x100, 0x101, 0x102, 0x103 },
+ }
+};
+
+static void apmu_parse_cfg(void (*fn)(struct resource *res, int cpu, int bit))
+{
+ u32 id;
+ int k;
+ int bit, index;
+ bool is_allowed;
+
+ for (k = 0; k < ARRAY_SIZE(apmu_config); k++) {
+ /* only enable the cluster that includes the boot CPU */
+ is_allowed = false;
+ for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) {
+ id = apmu_config[k].cpus[bit];
+ if (id >= 0) {
+ if (id == cpu_logical_map(0))
+ is_allowed = true;
+ }
+ }
+ if (!is_allowed)
+ continue;
+
+ for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) {
+ id = apmu_config[k].cpus[bit];
+ if (id >= 0) {
+ index = get_logical_index(id);
+ if (index >= 0)
+ fn(&apmu_config[k].iomem, index, bit);
+ }
+ }
+ }
+}
+
+void __init shmobile_smp_apmu_prepare_cpus(unsigned int max_cpus)
+{
+ /* install boot code shared by all CPUs */
+ shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
+ shmobile_boot_arg = MPIDR_HWID_BITMASK;
+
+ /* perform per-cpu setup */
+ apmu_parse_cfg(apmu_init_cpu);
+}
+
+int shmobile_smp_apmu_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /* For this particular CPU register boot vector */
+ shmobile_smp_hook(cpu, virt_to_phys(shmobile_invalidate_start), 0);
+
+ return apmu_wrap(cpu, apmu_power_on);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* nicked from arch/arm/mach-exynos/hotplug.c */
+static inline void cpu_enter_lowpower_a15(void)
+{
+ unsigned int v;
+
+ asm volatile(
+ " mrc p15, 0, %0, c1, c0, 0\n"
+ " bic %0, %0, %1\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ : "=&r" (v)
+ : "Ir" (CR_C)
+ : "cc");
+
+ flush_cache_louis();
+
+ asm volatile(
+ /*
+ * Turn off coherency
+ */
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " bic %0, %0, %1\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ : "=&r" (v)
+ : "Ir" (0x40)
+ : "cc");
+
+ isb();
+ dsb();
+}
+
+void shmobile_smp_apmu_cpu_die(unsigned int cpu)
+{
+ /* For this particular CPU deregister boot vector */
+ shmobile_smp_hook(cpu, 0, 0);
+
+ /* Select next sleep mode using the APMU */
+ apmu_wrap(cpu, apmu_power_off);
+
+ /* Do ARM specific CPU shutdown */
+ cpu_enter_lowpower_a15();
+
+ /* jump to shared mach-shmobile sleep / reset code */
+ shmobile_smp_sleep();
+}
+
+int shmobile_smp_apmu_cpu_kill(unsigned int cpu)
+{
+ return apmu_wrap(cpu, apmu_power_off_poll);
+}
+#endif