@@ -36,6 +36,8 @@
#define APMU 0xe6150000
#define CA15WUPCR 0x2010
+#define CA15PSTR 0x2040
+#define CA15CPUNCR(n) (0x2100 + (0x10 * (n)))
#define MERAM 0xe8080000
#define CCI_BASE 0xf0190000
@@ -83,7 +85,93 @@ static int __cpuinit r8a73a4_boot_second
return 0;
}
+#ifdef CONFIG_HOTPLUG_CPU
+static int r8a73a4_cpu_kill(unsigned int cpu)
+{
+ void __iomem *p;
+ int ret = 0;
+ int k;
+
+ /* this function is running on another CPU than the offline target,
+ * here all we need to do is to wait for the SoC to enter sleep mode.
+ */
+ p = ioremap_nocache(APMU, 0x3000);
+ for (k = 0; k < 1000; k++) {
+ if (((__raw_readl(p + CA15PSTR) >> (cpu * 4)) & 0x03) == 3) {
+ ret = 1;
+ break;
+ }
+
+ mdelay(1);
+ }
+ iounmap(p);
+
+ return ret;
+}
+
+/* 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();
+}
+
+static int r8a73a4_do_idle_core_standby(unsigned long unused)
+{
+ cpu_do_idle(); /* WFI triggers Core Standby */
+ return 0;
+}
+
+static void r8a73a4_cpu_die(unsigned int cpu)
+{
+ void __iomem *p;
+
+ /* hardware shutdown code running on the CPU that is being offlined */
+
+ /* select CPU shutdown mode */
+ p = ioremap_nocache(APMU, 0x3000);
+ __raw_writel(3, p + CA15CPUNCR(cpu)); /* CA15 Core Standby */
+ iounmap(p);
+
+ cpu_enter_lowpower_a15();
+ cpu_suspend(0, r8a73a4_do_idle_core_standby); /* really needed? */
+}
+
+static int r8a73a4_cpu_disable(unsigned int cpu)
+{
+ return 0; /* hotplug of any CPU is tested OK */
+}
+#endif
+
struct smp_operations r8a73a4_smp_ops __initdata = {
.smp_prepare_cpus = r8a73a4_smp_prepare_cpus,
.smp_boot_secondary = r8a73a4_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_kill = r8a73a4_cpu_kill,
+ .cpu_die = r8a73a4_cpu_die,
+ .cpu_disable = r8a73a4_cpu_disable,
+#endif
};
From: Magnus Damm <damm@opensource.se> Add CPU Hotplug prototype support for 4 x Cortex-A15 included in r8a73a4. Needs a rewrite to support more generic handling of CPU core power domains. Not ready for merge. Not-yet-Signed-off-by: Magnus Damm <damm@opensource.se> --- Developed and tested on top of v3.10-rc2, depends on "[PATCH] ARM: shmobile: r8a73a4 SMP prototype v1 (CA15 x 4)" arch/arm/mach-shmobile/smp-r8a73a4.c | 88 ++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+)