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-rw-r--r--arch/unicore32/kernel/process.c389
1 files changed, 389 insertions, 0 deletions
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
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+++ b/arch/unicore32/kernel/process.c
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+/*
+ * linux/arch/unicore32/kernel/process.c
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * 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/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/elfcore.h>
+#include <linux/pm.h>
+#include <linux/tick.h>
+#include <linux/utsname.h>
+#include <linux/uaccess.h>
+#include <linux/random.h>
+#include <linux/gpio.h>
+#include <linux/stacktrace.h>
+
+#include <asm/cacheflush.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/stacktrace.h>
+
+#include "setup.h"
+
+static const char * const processor_modes[] = {
+ "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
+ "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
+ "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
+ "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
+};
+
+/*
+ * The idle thread, has rather strange semantics for calling pm_idle,
+ * but this is what x86 does and we need to do the same, so that
+ * things like cpuidle get called in the same way.
+ */
+void cpu_idle(void)
+{
+ /* endless idle loop with no priority at all */
+ while (1) {
+ tick_nohz_stop_sched_tick(1);
+ while (!need_resched()) {
+ local_irq_disable();
+ stop_critical_timings();
+ cpu_do_idle();
+ local_irq_enable();
+ start_critical_timings();
+ }
+ tick_nohz_restart_sched_tick();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+static char reboot_mode = 'h';
+
+int __init reboot_setup(char *str)
+{
+ reboot_mode = str[0];
+ return 1;
+}
+
+__setup("reboot=", reboot_setup);
+
+void machine_halt(void)
+{
+ gpio_set_value(GPO_SOFT_OFF, 0);
+}
+
+/*
+ * Function pointers to optional machine specific functions
+ */
+void (*pm_power_off)(void) = NULL;
+
+void machine_power_off(void)
+{
+ if (pm_power_off)
+ pm_power_off();
+ machine_halt();
+}
+
+void machine_restart(char *cmd)
+{
+ /* Disable interrupts first */
+ local_irq_disable();
+
+ /*
+ * 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);
+
+ /* Clean and invalidate caches */
+ flush_cache_all();
+
+ /* Turn off caching */
+ cpu_proc_fin();
+
+ /* Push out any further dirty data, and ensure cache is empty */
+ flush_cache_all();
+
+ /*
+ * Now handle reboot code.
+ */
+ if (reboot_mode == 's') {
+ /* Jump into ROM at address 0xffff0000 */
+ cpu_reset(VECTORS_BASE);
+ } else {
+ PM_PLLSYSCFG = 0x00002001; /* cpu clk = 250M */
+ PM_PLLDDRCFG = 0x00100800; /* ddr clk = 44M */
+ PM_PLLVGACFG = 0x00002001; /* vga clk = 250M */
+
+ /* Use on-chip reset capability */
+ /* following instructions must be in one icache line */
+ __asm__ __volatile__(
+ " .align 5\n\t"
+ " stw %1, [%0]\n\t"
+ "201: ldw r0, [%0]\n\t"
+ " cmpsub.a r0, #0\n\t"
+ " bne 201b\n\t"
+ " stw %3, [%2]\n\t"
+ " nop; nop; nop\n\t"
+ /* prefetch 3 instructions at most */
+ :
+ : "r" ((unsigned long)&PM_PMCR),
+ "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
+ | PM_PMCR_CFBVGA),
+ "r" ((unsigned long)&RESETC_SWRR),
+ "r" (RESETC_SWRR_SRB)
+ : "r0", "memory");
+ }
+
+ /*
+ * Whoops - the architecture was unable to reboot.
+ * Tell the user!
+ */
+ mdelay(1000);
+ printk(KERN_EMERG "Reboot failed -- System halted\n");
+ do { } while (1);
+}
+
+void __show_regs(struct pt_regs *regs)
+{
+ unsigned long flags;
+ char buf[64];
+
+ printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
+ raw_smp_processor_id(), print_tainted(),
+ init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+ print_symbol("PC is at %s\n", instruction_pointer(regs));
+ print_symbol("LR is at %s\n", regs->UCreg_lr);
+ printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
+ "sp : %08lx ip : %08lx fp : %08lx\n",
+ regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
+ regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
+ printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n",
+ regs->UCreg_26, regs->UCreg_25,
+ regs->UCreg_24);
+ printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
+ regs->UCreg_23, regs->UCreg_22,
+ regs->UCreg_21, regs->UCreg_20);
+ printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
+ regs->UCreg_19, regs->UCreg_18,
+ regs->UCreg_17, regs->UCreg_16);
+ printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
+ regs->UCreg_15, regs->UCreg_14,
+ regs->UCreg_13, regs->UCreg_12);
+ printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
+ regs->UCreg_11, regs->UCreg_10,
+ regs->UCreg_09, regs->UCreg_08);
+ printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
+ regs->UCreg_07, regs->UCreg_06,
+ regs->UCreg_05, regs->UCreg_04);
+ printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
+ regs->UCreg_03, regs->UCreg_02,
+ regs->UCreg_01, regs->UCreg_00);
+
+ flags = regs->UCreg_asr;
+ buf[0] = flags & PSR_S_BIT ? 'S' : 's';
+ buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
+ buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
+ buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
+ buf[4] = '\0';
+
+ printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n",
+ buf, interrupts_enabled(regs) ? "n" : "ff",
+ fast_interrupts_enabled(regs) ? "n" : "ff",
+ processor_modes[processor_mode(regs)],
+ segment_eq(get_fs(), get_ds()) ? "kernel" : "user");
+ {
+ unsigned int ctrl;
+
+ buf[0] = '\0';
+ {
+ unsigned int transbase;
+ asm("movc %0, p0.c2, #0\n"
+ : "=r" (transbase));
+ snprintf(buf, sizeof(buf), " Table: %08x", transbase);
+ }
+ asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
+
+ printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
+ }
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ printk(KERN_DEFAULT "\n");
+ printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
+ task_pid_nr(current), current->comm);
+ __show_regs(regs);
+ __backtrace();
+}
+
+/*
+ * 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(thread->used_cp, 0, sizeof(thread->used_cp));
+ memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
+#ifdef CONFIG_UNICORE_FPU_F64
+ memset(&thread->fpstate, 0, sizeof(struct fp_state));
+#endif
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+
+int
+copy_thread(unsigned long clone_flags, unsigned long stack_start,
+ unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
+{
+ struct thread_info *thread = task_thread_info(p);
+ struct pt_regs *childregs = task_pt_regs(p);
+
+ *childregs = *regs;
+ childregs->UCreg_00 = 0;
+ childregs->UCreg_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;
+
+ if (clone_flags & CLONE_SETTLS)
+ childregs->UCreg_16 = regs->UCreg_03;
+
+ return 0;
+}
+
+/*
+ * Fill in the task's elfregs structure for a core dump.
+ */
+int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
+{
+ elf_core_copy_regs(elfregs, task_pt_regs(t));
+ return 1;
+}
+
+/*
+ * fill in the fpe structure for a core dump...
+ */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
+{
+ struct thread_info *thread = current_thread_info();
+ int used_math = thread->used_cp[1] | thread->used_cp[2];
+
+#ifdef CONFIG_UNICORE_FPU_F64
+ if (used_math)
+ memcpy(fp, &thread->fpstate, sizeof(*fp));
+#endif
+ return used_math != 0;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+/*
+ * 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.
+ */
+asm(".pushsection .text\n"
+" .align\n"
+" .type kernel_thread_helper, #function\n"
+"kernel_thread_helper:\n"
+" mov.a asr, r7\n"
+" mov r0, r4\n"
+" mov lr, r6\n"
+" mov pc, r5\n"
+" .size kernel_thread_helper, . - kernel_thread_helper\n"
+" .popsection");
+
+/*
+ * 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.UCreg_04 = (unsigned long)arg;
+ regs.UCreg_05 = (unsigned long)fn;
+ regs.UCreg_06 = (unsigned long)do_exit;
+ regs.UCreg_07 = PRIV_MODE;
+ regs.UCreg_pc = (unsigned long)kernel_thread_helper;
+ regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;
+
+ 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)
+{
+ struct stackframe frame;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ frame.fp = thread_saved_fp(p);
+ frame.sp = thread_saved_sp(p);
+ frame.lr = 0; /* recovered from the stack */
+ frame.pc = thread_saved_pc(p);
+ do {
+ int ret = unwind_frame(&frame);
+ if (ret < 0)
+ return 0;
+ if (!in_sched_functions(frame.pc))
+ return frame.pc;
+ } while ((count++) < 16);
+ return 0;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long range_end = mm->brk + 0x02000000;
+ return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
+
+/*
+ * The vectors page is always readable from user space for the
+ * atomic helpers and the signal restart code. Let's declare a mapping
+ * for it so it is visible through ptrace and /proc/<pid>/mem.
+ */
+
+int vectors_user_mapping(void)
+{
+ struct mm_struct *mm = current->mm;
+ return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
+ VM_READ | VM_EXEC |
+ VM_MAYREAD | VM_MAYEXEC |
+ VM_ALWAYSDUMP | VM_RESERVED,
+ NULL);
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
+}