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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/kernel/process.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm26/kernel/process.c')
-rw-r--r--arch/arm26/kernel/process.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/arch/arm26/kernel/process.c b/arch/arm26/kernel/process.c
new file mode 100644
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--- /dev/null
+++ b/arch/arm26/kernel/process.c
@@ -0,0 +1,401 @@
+/*
+ * linux/arch/arm26/kernel/process.c
+ *
+ * Copyright (C) 2003 Ian Molton - adapted for ARM26
+ * Copyright (C) 1996-2000 Russell King - Converted to ARM.
+ * Origional Copyright (C) 1995 Linus Torvalds
+ *
+ * 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 <stdarg.h>
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/leds.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+
+extern const char *processor_modes[];
+extern void setup_mm_for_reboot(char mode);
+
+static volatile int hlt_counter;
+
+void disable_hlt(void)
+{
+ hlt_counter++;
+}
+
+EXPORT_SYMBOL(disable_hlt);
+
+void enable_hlt(void)
+{
+ hlt_counter--;
+}
+
+EXPORT_SYMBOL(enable_hlt);
+
+static int __init nohlt_setup(char *__unused)
+{
+ hlt_counter = 1;
+ return 1;
+}
+
+static int __init hlt_setup(char *__unused)
+{
+ hlt_counter = 0;
+ return 1;
+}
+
+__setup("nohlt", nohlt_setup);
+__setup("hlt", hlt_setup);
+
+/*
+ * This is our default idle handler. We need to disable
+ * interrupts here to ensure we don't miss a wakeup call.
+ */
+void cpu_idle(void)
+{
+ /* endless idle loop with no priority at all */
+ preempt_disable();
+ while (1) {
+ while (!need_resched()) {
+ local_irq_disable();
+ if (!need_resched() && !hlt_counter)
+ local_irq_enable();
+ }
+ }
+ schedule();
+}
+
+static char reboot_mode = 'h';
+
+int __init reboot_setup(char *str)
+{
+ reboot_mode = str[0];
+ return 1;
+}
+
+__setup("reboot=", reboot_setup);
+
+/* ARM26 cant do these but we still need to define them. */
+void machine_halt(void)
+{
+}
+void machine_power_off(void)
+{
+}
+
+EXPORT_SYMBOL(machine_halt);
+EXPORT_SYMBOL(machine_power_off);
+
+void machine_restart(char * __unused)
+{
+ /*
+ * Clean and disable cache, and turn off interrupts
+ */
+ cpu_proc_fin();
+
+ /*
+ * 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.
+ */
+ setup_mm_for_reboot(reboot_mode);
+
+ /*
+ * copy branch instruction to reset location and call it
+ */
+
+ *(unsigned long *)0 = *(unsigned long *)0x03800000;
+ ((void(*)(void))0)();
+
+ /*
+ * Whoops - the architecture was unable to reboot.
+ * Tell the user! Should never happen...
+ */
+ mdelay(1000);
+ printk("Reboot failed -- System halted\n");
+ while (1);
+}
+
+EXPORT_SYMBOL(machine_restart);
+
+void show_regs(struct pt_regs * regs)
+{
+ unsigned long flags;
+
+ flags = condition_codes(regs);
+
+ printk("pc : [<%08lx>] lr : [<%08lx>] %s\n"
+ "sp : %08lx ip : %08lx fp : %08lx\n",
+ instruction_pointer(regs),
+ regs->ARM_lr, print_tainted(), regs->ARM_sp,
+ regs->ARM_ip, regs->ARM_fp);
+ printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
+ regs->ARM_r10, regs->ARM_r9,
+ regs->ARM_r8);
+ printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
+ regs->ARM_r7, regs->ARM_r6,
+ regs->ARM_r5, regs->ARM_r4);
+ printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
+ regs->ARM_r3, regs->ARM_r2,
+ regs->ARM_r1, regs->ARM_r0);
+ printk("Flags: %c%c%c%c",
+ flags & PSR_N_BIT ? 'N' : 'n',
+ flags & PSR_Z_BIT ? 'Z' : 'z',
+ flags & PSR_C_BIT ? 'C' : 'c',
+ flags & PSR_V_BIT ? 'V' : 'v');
+ printk(" IRQs o%s FIQs o%s Mode %s Segment %s\n",
+ interrupts_enabled(regs) ? "n" : "ff",
+ fast_interrupts_enabled(regs) ? "n" : "ff",
+ processor_modes[processor_mode(regs)],
+ get_fs() == get_ds() ? "kernel" : "user");
+}
+
+void show_fpregs(struct user_fp *regs)
+{
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ unsigned long *p;
+ char type;
+
+ p = (unsigned long *)(regs->fpregs + i);
+
+ switch (regs->ftype[i]) {
+ case 1: type = 'f'; break;
+ case 2: type = 'd'; break;
+ case 3: type = 'e'; break;
+ default: type = '?'; break;
+ }
+ if (regs->init_flag)
+ type = '?';
+
+ printk(" f%d(%c): %08lx %08lx %08lx%c",
+ i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
+ }
+
+
+ printk("FPSR: %08lx FPCR: %08lx\n",
+ (unsigned long)regs->fpsr,
+ (unsigned long)regs->fpcr);
+}
+
+/*
+ * Task structure and kernel stack allocation.
+ */
+static unsigned long *thread_info_head;
+static unsigned int nr_thread_info;
+
+extern unsigned long get_page_8k(int priority);
+extern void free_page_8k(unsigned long page);
+
+// FIXME - is this valid?
+#define EXTRA_TASK_STRUCT 0
+#define ll_alloc_task_struct() ((struct thread_info *)get_page_8k(GFP_KERNEL))
+#define ll_free_task_struct(p) free_page_8k((unsigned long)(p))
+
+//FIXME - do we use *task param below looks like we dont, which is ok?
+//FIXME - if EXTRA_TASK_STRUCT is zero we can optimise the below away permanently. *IF* its supposed to be zero.
+struct thread_info *alloc_thread_info(struct task_struct *task)
+{
+ struct thread_info *thread = NULL;
+
+ if (EXTRA_TASK_STRUCT) {
+ unsigned long *p = thread_info_head;
+
+ if (p) {
+ thread_info_head = (unsigned long *)p[0];
+ nr_thread_info -= 1;
+ }
+ thread = (struct thread_info *)p;
+ }
+
+ if (!thread)
+ thread = ll_alloc_task_struct();
+
+#ifdef CONFIG_MAGIC_SYSRQ
+ /*
+ * The stack must be cleared if you want SYSRQ-T to
+ * give sensible stack usage information
+ */
+ if (thread) {
+ char *p = (char *)thread;
+ memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE);
+ }
+#endif
+ return thread;
+}
+
+void free_thread_info(struct thread_info *thread)
+{
+ if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) {
+ unsigned long *p = (unsigned long *)thread;
+ p[0] = (unsigned long)thread_info_head;
+ thread_info_head = p;
+ nr_thread_info += 1;
+ } else
+ ll_free_task_struct(thread);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+void flush_thread(void)
+{
+ struct thread_info *thread = current_thread_info();
+ struct task_struct *tsk = current;
+
+ memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
+ memset(&thread->fpstate, 0, sizeof(union fp_state));
+
+ clear_used_math();
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+
+int
+copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
+ unsigned long unused, struct task_struct *p, struct pt_regs *regs)
+{
+ struct thread_info *thread = p->thread_info;
+ struct pt_regs *childregs;
+
+ childregs = __get_user_regs(thread);
+ *childregs = *regs;
+ childregs->ARM_r0 = 0;
+ childregs->ARM_sp = stack_start;
+
+ memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
+ thread->cpu_context.sp = (unsigned long)childregs;
+ thread->cpu_context.pc = (unsigned long)ret_from_fork | MODE_SVC26 | PSR_I_BIT;
+
+ return 0;
+}
+
+/*
+ * fill in the fpe structure for a core dump...
+ */
+int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
+{
+ struct thread_info *thread = current_thread_info();
+ int used_math = !!used_math();
+
+ if (used_math)
+ memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
+
+ return used_math;
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs * regs, struct user * dump)
+{
+ struct task_struct *tsk = current;
+
+ dump->magic = CMAGIC;
+ dump->start_code = tsk->mm->start_code;
+ dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
+
+ dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
+ dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ dump->u_ssize = 0;
+
+ dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
+ dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
+ dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn;
+ dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn;
+ dump->u_debugreg[4] = tsk->thread.debug.nsaved;
+
+ if (dump->start_stack < 0x04000000)
+ dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
+
+ dump->regs = *regs;
+ dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
+}
+
+/*
+ * Shuffle the argument into the correct register before calling the
+ * thread function. r1 is the thread argument, r2 is the pointer to
+ * the thread function, and r3 points to the exit function.
+ * FIXME - make sure this is right - the older code used to zero fp
+ * and cause the parent to call sys_exit (do_exit in this version)
+ */
+extern void kernel_thread_helper(void);
+
+asm( ".section .text\n"
+" .align\n"
+" .type kernel_thread_helper, #function\n"
+"kernel_thread_helper:\n"
+" mov r0, r1\n"
+" mov lr, r3\n"
+" mov pc, r2\n"
+" .size kernel_thread_helper, . - kernel_thread_helper\n"
+" .previous");
+
+/*
+ * Create a kernel thread.
+ */
+pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+
+ regs.ARM_r1 = (unsigned long)arg;
+ regs.ARM_r2 = (unsigned long)fn;
+ regs.ARM_r3 = (unsigned long)do_exit;
+ regs.ARM_pc = (unsigned long)kernel_thread_helper | MODE_SVC26;
+
+ return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long fp, lr;
+ unsigned long stack_page;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ stack_page = 4096 + (unsigned long)p;
+ fp = thread_saved_fp(p);
+ do {
+ if (fp < stack_page || fp > 4092+stack_page)
+ return 0;
+ lr = pc_pointer (((unsigned long *)fp)[-1]);
+ if (!in_sched_functions(lr))
+ return lr;
+ fp = *(unsigned long *) (fp - 12);
+ } while (count ++ < 16);
+ return 0;
+}