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-rw-r--r--arch/arm/kernel/process.c130
1 files changed, 104 insertions, 26 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 6ea02d891..68bf5aa1f 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -34,7 +34,6 @@
#include <linux/init.h>
#include <asm/uaccess.h>
-#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/io.h>
@@ -55,46 +54,37 @@ void enable_hlt(void)
}
/*
- * The idle loop on an arm..
+ * The idle loop on an ARM...
*/
asmlinkage int sys_idle(void)
{
- int ret = -EPERM;
-
- lock_kernel();
if (current->pid != 0)
- goto out;
+ return -EPERM;
+
/* endless idle loop with no priority at all */
- current->priority = -100;
- for (;;)
- {
+ while (1) {
+ if (!current->need_resched && !hlt_counter)
+ proc_idle();
+ current->policy = SCHED_YIELD;
+ schedule();
+#ifndef CONFIG_NO_PGT_CACHE
check_pgt_cache();
-#if 0 //def ARCH_IDLE_OK
- if (!hlt_counter && !current->need_resched)
- proc_idle ();
#endif
- run_task_queue(&tq_scheduler);
- schedule();
}
- ret = 0;
-out:
- unlock_kernel();
- return ret;
}
+static char reboot_mode = 'h';
+
__initfunc(void reboot_setup(char *str, int *ints))
{
+ reboot_mode = str[0];
}
-/*
- * This routine reboots the machine by resetting the expansion cards via
- * their loaders, turning off the processor cache (if ARM3), copying the
- * first instruction of the ROM to 0, and executing it there.
- */
void machine_restart(char * __unused)
{
- proc_hard_reset ();
- arch_hard_reset ();
+ arch_reset(reboot_mode);
+ panic("Reboot failed\n");
+ while (1);
}
void machine_halt(void)
@@ -150,6 +140,67 @@ void show_regs(struct pt_regs * regs)
}
/*
+ * Task structure and kernel stack allocation.
+ *
+ * Taken from the i386 version.
+ */
+#ifdef CONFIG_CPU_32
+#define EXTRA_TASK_STRUCT 8
+static struct task_struct *task_struct_stack[EXTRA_TASK_STRUCT];
+static int task_struct_stack_ptr = -1;
+#endif
+
+struct task_struct *alloc_task_struct(void)
+{
+ struct task_struct *tsk;
+
+#ifndef EXTRA_TASK_STRUCT
+ tsk = ll_alloc_task_struct();
+#else
+ int index;
+
+ index = task_struct_stack_ptr;
+ if (index >= EXTRA_TASK_STRUCT/2)
+ goto use_cache;
+
+ tsk = ll_alloc_task_struct();
+
+ if (!tsk) {
+ index = task_struct_stack_ptr;
+
+ if (index >= 0) {
+use_cache: tsk = task_struct_stack[index];
+ task_struct_stack_ptr = index - 1;
+ }
+ }
+#endif
+#ifdef CONFIG_SYSRQ
+ /* You need this if you want SYSRQ-T to give sensible stack
+ * usage information
+ */
+ if (tsk) {
+ char *p = (char *)tsk;
+ memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE);
+ }
+#endif
+
+ return tsk;
+}
+
+void free_task_struct(struct task_struct *p)
+{
+#ifdef EXTRA_TASK_STRUCT
+ int index = task_struct_stack_ptr + 1;
+
+ if (index < EXTRA_TASK_STRUCT) {
+ task_struct_stack[index] = p;
+ task_struct_stack_ptr = index;
+ } else
+#endif
+ ll_free_task_struct(p);
+}
+
+/*
* Free current thread data structures etc..
*/
void exit_thread(void)
@@ -179,9 +230,10 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
childregs = ((struct pt_regs *)((unsigned long)p + 8192)) - 1;
*childregs = *regs;
childregs->ARM_r0 = 0;
+ childregs->ARM_sp = esp;
save = ((struct context_save_struct *)(childregs)) - 1;
- copy_thread_css(save);
+ init_thread_css(save);
p->tss.save = save;
return 0;
@@ -224,3 +276,29 @@ void dump_thread(struct pt_regs * regs, struct user * dump)
dump->regs = *regs;
dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
}
+
+/*
+ * This is the mechanism for creating a new kernel thread.
+ *
+ * NOTE! Only a kernel-only process(ie the swapper or direct descendants
+ * who haven't done an "execve()") should use this: it will work within
+ * a system call from a "real" process, but the process memory space will
+ * not be free'd until both the parent and the child have exited.
+ */
+pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ extern int sys_exit(int) __attribute__((noreturn));
+ pid_t __ret;
+
+ __asm__ __volatile__(
+ "mov r0, %1 @ kernel_thread sys_clone\n"
+" mov r1, #0\n"
+ __syscall(clone)"\n"
+" mov %0, r0"
+ : "=r" (__ret)
+ : "Ir" (flags | CLONE_VM) : "r0", "r1");
+ if (__ret == 0)
+ sys_exit((fn)(arg));
+ return __ret;
+}
+