![Alex Dowad](/assets/img/avatar_default.png)
The 'arg' argument to copy_thread() is only ever used when forking a new kernel thread. Hence, rename it to 'kthread_arg' for clarity. Signed-off-by: Alex Dowad <alexinbeijing@gmail.com> Signed-off-by: James Hogan <james.hogan@imgtec.com>
445 lines
10 KiB
C
445 lines
10 KiB
C
/*
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* Copyright (C) 2005,2006,2007,2008,2009,2010,2011 Imagination Technologies
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*
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* This file contains the architecture-dependent parts of process handling.
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*
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*/
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#include <linux/errno.h>
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#include <linux/export.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/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/reboot.h>
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#include <linux/elfcore.h>
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#include <linux/fs.h>
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#include <linux/tick.h>
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#include <linux/slab.h>
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#include <linux/mman.h>
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#include <linux/pm.h>
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#include <linux/syscalls.h>
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#include <linux/uaccess.h>
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#include <linux/smp.h>
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#include <asm/core_reg.h>
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#include <asm/user_gateway.h>
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#include <asm/tcm.h>
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#include <asm/traps.h>
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#include <asm/switch_to.h>
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/*
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* Wait for the next interrupt and enable local interrupts
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*/
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void arch_cpu_idle(void)
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{
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int tmp;
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/*
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* Quickly jump straight into the interrupt entry point without actually
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* triggering an interrupt. When TXSTATI gets read the processor will
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* block until an interrupt is triggered.
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*/
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asm volatile (/* Switch into ISTAT mode */
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"RTH\n\t"
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/* Enable local interrupts */
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"MOV TXMASKI, %1\n\t"
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/*
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* We can't directly "SWAP PC, PCX", so we swap via a
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* temporary. Essentially we do:
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* PCX_new = 1f (the place to continue execution)
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* PC = PCX_old
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*/
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"ADD %0, CPC0, #(1f-.)\n\t"
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"SWAP PCX, %0\n\t"
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"MOV PC, %0\n"
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/* Continue execution here with interrupts enabled */
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"1:"
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: "=a" (tmp)
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: "r" (get_trigger_mask()));
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}
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#ifdef CONFIG_HOTPLUG_CPU
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void arch_cpu_idle_dead(void)
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{
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cpu_die();
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}
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#endif
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void (*pm_power_off)(void);
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EXPORT_SYMBOL(pm_power_off);
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void (*soc_restart)(char *cmd);
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void (*soc_halt)(void);
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void machine_restart(char *cmd)
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{
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if (soc_restart)
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soc_restart(cmd);
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hard_processor_halt(HALT_OK);
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}
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void machine_halt(void)
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{
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if (soc_halt)
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soc_halt();
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smp_send_stop();
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hard_processor_halt(HALT_OK);
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}
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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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smp_send_stop();
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hard_processor_halt(HALT_OK);
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}
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#define FLAG_Z 0x8
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#define FLAG_N 0x4
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#define FLAG_O 0x2
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#define FLAG_C 0x1
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void show_regs(struct pt_regs *regs)
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{
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int i;
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const char *AX0_names[] = {"A0StP", "A0FrP"};
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const char *AX1_names[] = {"A1GbP", "A1LbP"};
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const char *DX0_names[] = {
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"D0Re0",
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"D0Ar6",
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"D0Ar4",
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"D0Ar2",
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"D0FrT",
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"D0.5 ",
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"D0.6 ",
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"D0.7 "
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};
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const char *DX1_names[] = {
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"D1Re0",
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"D1Ar5",
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"D1Ar3",
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"D1Ar1",
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"D1RtP",
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"D1.5 ",
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"D1.6 ",
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"D1.7 "
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};
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show_regs_print_info(KERN_INFO);
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pr_info(" pt_regs @ %p\n", regs);
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pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
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pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
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regs->ctx.Flags & FLAG_Z ? 'Z' : 'z',
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regs->ctx.Flags & FLAG_N ? 'N' : 'n',
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regs->ctx.Flags & FLAG_O ? 'O' : 'o',
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regs->ctx.Flags & FLAG_C ? 'C' : 'c');
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pr_info(" TXRPT = 0x%08x\n", regs->ctx.CurrRPT);
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pr_info(" PC = 0x%08x\n", regs->ctx.CurrPC);
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/* AX regs */
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for (i = 0; i < 2; i++) {
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pr_info(" %s = 0x%08x ",
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AX0_names[i],
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regs->ctx.AX[i].U0);
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printk(" %s = 0x%08x\n",
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AX1_names[i],
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regs->ctx.AX[i].U1);
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}
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if (regs->ctx.SaveMask & TBICTX_XEXT_BIT)
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pr_warn(" Extended state present - AX2.[01] will be WRONG\n");
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/* Special place with AXx.2 */
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pr_info(" A0.2 = 0x%08x ",
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regs->ctx.Ext.AX2.U0);
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printk(" A1.2 = 0x%08x\n",
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regs->ctx.Ext.AX2.U1);
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/* 'extended' AX regs (nominally, just AXx.3) */
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for (i = 0; i < (TBICTX_AX_REGS - 3); i++) {
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pr_info(" A0.%d = 0x%08x ", i + 3, regs->ctx.AX3[i].U0);
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printk(" A1.%d = 0x%08x\n", i + 3, regs->ctx.AX3[i].U1);
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}
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for (i = 0; i < 8; i++) {
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pr_info(" %s = 0x%08x ", DX0_names[i], regs->ctx.DX[i].U0);
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printk(" %s = 0x%08x\n", DX1_names[i], regs->ctx.DX[i].U1);
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}
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show_trace(NULL, (unsigned long *)regs->ctx.AX[0].U0, regs);
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}
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/*
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* Copy architecture-specific thread state
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*/
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int copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long kthread_arg, struct task_struct *tsk)
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{
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struct pt_regs *childregs = task_pt_regs(tsk);
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void *kernel_context = ((void *) childregs +
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sizeof(struct pt_regs));
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unsigned long global_base;
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BUG_ON(((unsigned long)childregs) & 0x7);
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BUG_ON(((unsigned long)kernel_context) & 0x7);
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memset(&tsk->thread.kernel_context, 0,
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sizeof(tsk->thread.kernel_context));
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tsk->thread.kernel_context = __TBISwitchInit(kernel_context,
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ret_from_fork,
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0, 0);
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if (unlikely(tsk->flags & PF_KTHREAD)) {
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/*
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* Make sure we don't leak any kernel data to child's regs
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* if kernel thread becomes a userspace thread in the future
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*/
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memset(childregs, 0 , sizeof(struct pt_regs));
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global_base = __core_reg_get(A1GbP);
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childregs->ctx.AX[0].U1 = (unsigned long) global_base;
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childregs->ctx.AX[0].U0 = (unsigned long) kernel_context;
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/* Set D1Ar1=kthread_arg and D1RtP=usp (fn) */
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childregs->ctx.DX[4].U1 = usp;
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childregs->ctx.DX[3].U1 = kthread_arg;
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tsk->thread.int_depth = 2;
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return 0;
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}
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/*
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* Get a pointer to where the new child's register block should have
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* been pushed.
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* The Meta's stack grows upwards, and the context is the the first
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* thing to be pushed by TBX (phew)
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*/
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*childregs = *current_pt_regs();
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/* Set the correct stack for the clone mode */
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if (usp)
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childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
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tsk->thread.int_depth = 1;
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/* set return value for child process */
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childregs->ctx.DX[0].U0 = 0;
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/* The TLS pointer is passed as an argument to sys_clone. */
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if (clone_flags & CLONE_SETTLS)
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tsk->thread.tls_ptr =
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(__force void __user *)childregs->ctx.DX[1].U1;
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#ifdef CONFIG_METAG_FPU
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if (tsk->thread.fpu_context) {
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struct meta_fpu_context *ctx;
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ctx = kmemdup(tsk->thread.fpu_context,
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sizeof(struct meta_fpu_context), GFP_ATOMIC);
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tsk->thread.fpu_context = ctx;
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}
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#endif
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#ifdef CONFIG_METAG_DSP
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if (tsk->thread.dsp_context) {
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struct meta_ext_context *ctx;
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int i;
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ctx = kmemdup(tsk->thread.dsp_context,
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sizeof(struct meta_ext_context), GFP_ATOMIC);
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for (i = 0; i < 2; i++)
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ctx->ram[i] = kmemdup(ctx->ram[i], ctx->ram_sz[i],
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GFP_ATOMIC);
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tsk->thread.dsp_context = ctx;
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}
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#endif
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return 0;
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}
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#ifdef CONFIG_METAG_FPU
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static void alloc_fpu_context(struct thread_struct *thread)
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{
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thread->fpu_context = kzalloc(sizeof(struct meta_fpu_context),
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GFP_ATOMIC);
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}
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static void clear_fpu(struct thread_struct *thread)
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{
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thread->user_flags &= ~TBICTX_FPAC_BIT;
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kfree(thread->fpu_context);
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thread->fpu_context = NULL;
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}
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#else
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static void clear_fpu(struct thread_struct *thread)
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{
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}
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#endif
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#ifdef CONFIG_METAG_DSP
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static void clear_dsp(struct thread_struct *thread)
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{
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if (thread->dsp_context) {
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kfree(thread->dsp_context->ram[0]);
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kfree(thread->dsp_context->ram[1]);
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kfree(thread->dsp_context);
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thread->dsp_context = NULL;
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}
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__core_reg_set(D0.8, 0);
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}
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#else
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static void clear_dsp(struct thread_struct *thread)
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{
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}
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#endif
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struct task_struct *__sched __switch_to(struct task_struct *prev,
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struct task_struct *next)
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{
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TBIRES to, from;
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to.Switch.pCtx = next->thread.kernel_context;
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to.Switch.pPara = prev;
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#ifdef CONFIG_METAG_FPU
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if (prev->thread.user_flags & TBICTX_FPAC_BIT) {
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struct pt_regs *regs = task_pt_regs(prev);
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TBIRES state;
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state.Sig.SaveMask = prev->thread.user_flags;
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state.Sig.pCtx = ®s->ctx;
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if (!prev->thread.fpu_context)
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alloc_fpu_context(&prev->thread);
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if (prev->thread.fpu_context)
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__TBICtxFPUSave(state, prev->thread.fpu_context);
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}
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/*
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* Force a restore of the FPU context next time this process is
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* scheduled.
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*/
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if (prev->thread.fpu_context)
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prev->thread.fpu_context->needs_restore = true;
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#endif
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from = __TBISwitch(to, &prev->thread.kernel_context);
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/* Restore TLS pointer for this process. */
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set_gateway_tls(current->thread.tls_ptr);
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return (struct task_struct *) from.Switch.pPara;
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}
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void flush_thread(void)
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{
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clear_fpu(¤t->thread);
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clear_dsp(¤t->thread);
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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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clear_fpu(¤t->thread);
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clear_dsp(¤t->thread);
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}
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/* TODO: figure out how to unwind the kernel stack here to figure out
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* where we went to sleep. */
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unsigned long get_wchan(struct task_struct *p)
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{
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return 0;
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}
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int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
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{
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/* Returning 0 indicates that the FPU state was not stored (as it was
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* not in use) */
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return 0;
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}
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#ifdef CONFIG_METAG_USER_TCM
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#define ELF_MIN_ALIGN PAGE_SIZE
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#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
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#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
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#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
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#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
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unsigned long __metag_elf_map(struct file *filep, unsigned long addr,
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struct elf_phdr *eppnt, int prot, int type,
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unsigned long total_size)
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{
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unsigned long map_addr, size;
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unsigned long page_off = ELF_PAGEOFFSET(eppnt->p_vaddr);
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unsigned long raw_size = eppnt->p_filesz + page_off;
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unsigned long off = eppnt->p_offset - page_off;
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unsigned int tcm_tag;
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addr = ELF_PAGESTART(addr);
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size = ELF_PAGEALIGN(raw_size);
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/* mmap() will return -EINVAL if given a zero size, but a
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* segment with zero filesize is perfectly valid */
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if (!size)
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return addr;
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tcm_tag = tcm_lookup_tag(addr);
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if (tcm_tag != TCM_INVALID_TAG)
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type &= ~MAP_FIXED;
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/*
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* total_size is the size of the ELF (interpreter) image.
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* The _first_ mmap needs to know the full size, otherwise
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* randomization might put this image into an overlapping
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* position with the ELF binary image. (since size < total_size)
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* So we first map the 'big' image - and unmap the remainder at
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* the end. (which unmap is needed for ELF images with holes.)
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*/
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if (total_size) {
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total_size = ELF_PAGEALIGN(total_size);
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map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
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if (!BAD_ADDR(map_addr))
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vm_munmap(map_addr+size, total_size-size);
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} else
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map_addr = vm_mmap(filep, addr, size, prot, type, off);
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if (!BAD_ADDR(map_addr) && tcm_tag != TCM_INVALID_TAG) {
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struct tcm_allocation *tcm;
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unsigned long tcm_addr;
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tcm = kmalloc(sizeof(*tcm), GFP_KERNEL);
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if (!tcm)
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return -ENOMEM;
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tcm_addr = tcm_alloc(tcm_tag, raw_size);
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if (tcm_addr != addr) {
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kfree(tcm);
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return -ENOMEM;
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}
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tcm->tag = tcm_tag;
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tcm->addr = tcm_addr;
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tcm->size = raw_size;
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list_add(&tcm->list, ¤t->mm->context.tcm);
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eppnt->p_vaddr = map_addr;
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if (copy_from_user((void *) addr, (void __user *) map_addr,
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raw_size))
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return -EFAULT;
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}
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return map_addr;
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}
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#endif
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