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