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151 lines
3.2 KiB
151 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Port on Texas Instruments TMS320C6x architecture |
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* |
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* Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated |
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* Author: Aurelien Jacquiot ([email protected]) |
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*/ |
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#include <linux/module.h> |
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#include <linux/unistd.h> |
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#include <linux/ptrace.h> |
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#include <linux/init_task.h> |
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#include <linux/tick.h> |
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#include <linux/mqueue.h> |
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#include <linux/syscalls.h> |
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#include <linux/reboot.h> |
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#include <linux/sched/task.h> |
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#include <linux/sched/task_stack.h> |
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#include <asm/syscalls.h> |
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/* hooks for board specific support */ |
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void (*c6x_restart)(void); |
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void (*c6x_halt)(void); |
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extern asmlinkage void ret_from_fork(void); |
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extern asmlinkage void ret_from_kernel_thread(void); |
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/* |
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* power off function, if any |
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*/ |
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void (*pm_power_off)(void); |
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EXPORT_SYMBOL(pm_power_off); |
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void arch_cpu_idle(void) |
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{ |
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unsigned long tmp; |
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/* |
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* Put local_irq_enable and idle in same execute packet |
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* to make them atomic and avoid race to idle with |
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* interrupts enabled. |
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*/ |
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asm volatile (" mvc .s2 CSR,%0\n" |
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" or .d2 1,%0,%0\n" |
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" mvc .s2 %0,CSR\n" |
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"|| idle\n" |
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: "=b"(tmp)); |
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} |
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static void halt_loop(void) |
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{ |
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printk(KERN_EMERG "System Halted, OK to turn off power\n"); |
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local_irq_disable(); |
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while (1) |
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asm volatile("idle\n"); |
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} |
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void machine_restart(char *__unused) |
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{ |
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if (c6x_restart) |
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c6x_restart(); |
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halt_loop(); |
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} |
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void machine_halt(void) |
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{ |
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if (c6x_halt) |
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c6x_halt(); |
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halt_loop(); |
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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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halt_loop(); |
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} |
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void flush_thread(void) |
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{ |
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} |
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/* |
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* Do necessary setup to start up a newly executed thread. |
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*/ |
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void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp) |
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{ |
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/* |
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* The binfmt loader will setup a "full" stack, but the C6X |
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* operates an "empty" stack. So we adjust the usp so that |
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* argc doesn't get destroyed if an interrupt is taken before |
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* it is read from the stack. |
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* |
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* NB: Library startup code needs to match this. |
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*/ |
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usp -= 8; |
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regs->pc = pc; |
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regs->sp = usp; |
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regs->tsr |= 0x40; /* set user mode */ |
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current->thread.usp = usp; |
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} |
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/* |
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* Copy a new thread context in its stack. |
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*/ |
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int copy_thread(unsigned long clone_flags, unsigned long usp, |
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unsigned long ustk_size, struct task_struct *p, |
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unsigned long tls) |
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{ |
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struct pt_regs *childregs; |
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childregs = task_pt_regs(p); |
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if (unlikely(p->flags & PF_KTHREAD)) { |
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/* case of __kernel_thread: we return to supervisor space */ |
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memset(childregs, 0, sizeof(struct pt_regs)); |
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childregs->sp = (unsigned long)(childregs + 1); |
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p->thread.pc = (unsigned long) ret_from_kernel_thread; |
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childregs->a0 = usp; /* function */ |
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childregs->a1 = ustk_size; /* argument */ |
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} else { |
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/* Otherwise use the given stack */ |
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*childregs = *current_pt_regs(); |
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if (usp) |
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childregs->sp = usp; |
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p->thread.pc = (unsigned long) ret_from_fork; |
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} |
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/* Set usp/ksp */ |
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p->thread.usp = childregs->sp; |
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thread_saved_ksp(p) = (unsigned long)childregs - 8; |
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p->thread.wchan = p->thread.pc; |
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#ifdef __DSBT__ |
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{ |
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unsigned long dp; |
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asm volatile ("mv .S2 b14,%0\n" : "=b"(dp)); |
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thread_saved_dp(p) = dp; |
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if (usp == -1) |
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childregs->dp = dp; |
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} |
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#endif |
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return 0; |
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} |
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unsigned long get_wchan(struct task_struct *p) |
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{ |
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return p->thread.wchan; |
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}
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