ARM: reset: implement soft_restart for jumping to a physical address

[pandora-kernel.git] / arch / arm / kernel / process.c

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index a71ea61..7a77f2d 100644 (file)
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -92,17 +92,23 @@ static int __init hlt_setup(char *__unused)
 __setup("nohlt", nohlt_setup);
 __setup("hlt", hlt_setup);
 
 __setup("nohlt", nohlt_setup);
 __setup("hlt", hlt_setup);
 

-void soft_restart(unsigned long addr)
+extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
+typedef void (*phys_reset_t)(unsigned long);
+
+/*
+ * A temporary stack to use for CPU reset. This is static so that we
+ * don't clobber it with the identity mapping. When running with this
+ * stack, any references to the current task *will not work* so you
+ * should really do as little as possible before jumping to your reset
+ * code.
+ */
+static u64 soft_restart_stack[16];
+
+static void __soft_restart(void *addr)

 {
 {

-       /* Disable interrupts first */
-       local_irq_disable();
-       local_fiq_disable();
+       phys_reset_t phys_reset;

 
 

-       /*
-        * Tell the mm system that we are going to reboot -
-        * we may need it to insert some 1:1 mappings so that
-        * soft boot works.
-        */
+       /* Take out a flat memory mapping. */

        setup_mm_for_reboot();
 
        /* Clean and invalidate caches */
        setup_mm_for_reboot();
 
        /* Clean and invalidate caches */


@@ -114,7 +120,31 @@ void soft_restart(unsigned long addr)
        /* Push out any further dirty data, and ensure cache is empty */
        flush_cache_all();
 
        /* Push out any further dirty data, and ensure cache is empty */
        flush_cache_all();
 

-       cpu_reset(addr);
+       /* Switch to the identity mapping. */
+       phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
+       phys_reset((unsigned long)addr);
+
+       /* Should never get here. */
+       BUG();
+}
+
+void soft_restart(unsigned long addr)
+{
+       u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
+
+       /* Disable interrupts first */
+       local_irq_disable();
+       local_fiq_disable();
+
+       /* Disable the L2 if we're the last man standing. */
+       if (num_online_cpus() == 1)
+               outer_disable();
+
+       /* Change to the new stack and continue with the reset. */
+       call_with_stack(__soft_restart, (void *)addr, (void *)stack);
+
+       /* Should never get here. */
+       BUG();

 }
 
 void arm_machine_restart(char mode, const char *cmd)
 }
 
 void arm_machine_restart(char mode, const char *cmd)