Merge tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64

Pull arm64 fixes from Catalin Marinas:
 - Stack size increased to 16K (similar to other 64-bit architectures)
 - Additional cache flushing for secondary CPUs boot mode

* tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
  arm64: Change kernel stack size to 16K
  arm64: Fix definition of arm_pm_restart to match the declaration
  arm64: virt: ensure visibility of __boot_cpu_mode

arch/arm64/include/asm/thread_info.h

@@ -24,10 +24,10 @@
 #include <linux/compiler.h>
 
 #ifndef CONFIG_ARM64_64K_PAGES
-#define THREAD_SIZE_ORDER	1
+#define THREAD_SIZE_ORDER	2
 #endif
 
-#define THREAD_SIZE		8192
+#define THREAD_SIZE		16384
 #define THREAD_START_SP		(THREAD_SIZE - 16)
 
 #ifndef __ASSEMBLY__

arch/arm64/include/asm/virt.h

@@ -21,6 +21,7 @@
 #define BOOT_CPU_MODE_EL2	(0x0e12b007)
 
 #ifndef __ASSEMBLY__
+#include <asm/cacheflush.h>
 
 /*
  * __boot_cpu_mode records what mode CPUs were booted in.
@@ -36,9 +37,20 @@ extern u32 __boot_cpu_mode[2];
 void __hyp_set_vectors(phys_addr_t phys_vector_base);
 phys_addr_t __hyp_get_vectors(void);
 
+static inline void sync_boot_mode(void)
+{
+	/*
+	 * As secondaries write to __boot_cpu_mode with caches disabled, we
+	 * must flush the corresponding cache entries to ensure the visibility
+	 * of their writes.
+	 */
+	__flush_dcache_area(__boot_cpu_mode, sizeof(__boot_cpu_mode));
+}
+
 /* Reports the availability of HYP mode */
 static inline bool is_hyp_mode_available(void)
 {
+	sync_boot_mode();
 	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
 		__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
 }
@@ -46,6 +58,7 @@ static inline bool is_hyp_mode_available(void)
 /* Check if the bootloader has booted CPUs in different modes */
 static inline bool is_hyp_mode_mismatched(void)
 {
+	sync_boot_mode();
 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
 }
 

arch/arm64/kernel/entry.S

@@ -121,7 +121,7 @@
 
 	.macro	get_thread_info, rd
 	mov	\rd, sp
-	and	\rd, \rd, #~((1 << 13) - 1)	// top of 8K stack
+	and	\rd, \rd, #~(THREAD_SIZE - 1)	// top of stack
 	.endm
 
 /*

arch/arm64/kernel/process.c

@@ -81,7 +81,7 @@ void soft_restart(unsigned long addr)
 void (*pm_power_off)(void);
 EXPORT_SYMBOL_GPL(pm_power_off);
 
-void (*arm_pm_restart)(char str, const char *cmd);
+void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 EXPORT_SYMBOL_GPL(arm_pm_restart);
 
 void arch_cpu_idle_prepare(void)