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author | Ley Foon Tan <lftan@altera.com> | 2014-11-06 10:19:47 +0300 |
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committer | Ley Foon Tan <lftan@altera.com> | 2014-12-08 07:55:53 +0300 |
commit | 71995e4d004f6afbc86cc4a80c4a281f6c00b07f (patch) | |
tree | 68139e7bb9dfee02e23384224e2fa20082e55653 /arch/nios2/kernel/process.c | |
parent | cbd15b3fadc27e81a6e8a3d38ce13cde5ce7cb71 (diff) | |
download | linux-71995e4d004f6afbc86cc4a80c4a281f6c00b07f.tar.xz |
nios2: Process management
This patch adds support for thread creation and context switching.
Signed-off-by: Ley Foon Tan <lftan@altera.com>
Diffstat (limited to 'arch/nios2/kernel/process.c')
-rw-r--r-- | arch/nios2/kernel/process.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c new file mode 100644 index 000000000000..0e075b5ad2a5 --- /dev/null +++ b/arch/nios2/kernel/process.c @@ -0,0 +1,258 @@ +/* + * Architecture-dependent parts of process handling. + * + * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch> + * Copyright (C) 2009 Wind River Systems Inc + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * Copyright (C) 2004 Microtronix Datacom Ltd + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/tick.h> +#include <linux/uaccess.h> + +#include <asm/unistd.h> +#include <asm/traps.h> +#include <asm/cpuinfo.h> + +asmlinkage void ret_from_fork(void); +asmlinkage void ret_from_kernel_thread(void); + +void (*pm_power_off)(void) = NULL; +EXPORT_SYMBOL(pm_power_off); + +void arch_cpu_idle(void) +{ + local_irq_enable(); +} + +/* + * The development boards have no way to pull a board reset. Just jump to the + * cpu reset address and let the boot loader or the code in head.S take care of + * resetting peripherals. + */ +void machine_restart(char *__unused) +{ + pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr); + local_irq_disable(); + __asm__ __volatile__ ( + "jmp %0\n\t" + : + : "r" (cpuinfo.reset_addr) + : "r4"); +} + +void machine_halt(void) +{ + pr_notice("Machine halt...\n"); + local_irq_disable(); + for (;;) + ; +} + +/* + * There is no way to power off the development boards. So just spin for now. If + * we ever have a way of resetting a board using a GPIO we should add that here. + */ +void machine_power_off(void) +{ + pr_notice("Machine power off...\n"); + local_irq_disable(); + for (;;) + ; +} + +void show_regs(struct pt_regs *regs) +{ + pr_notice("\n"); + show_regs_print_info(KERN_DEFAULT); + + pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n", + regs->r1, regs->r2, regs->r3, regs->r4); + + pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n", + regs->r5, regs->r6, regs->r7, regs->r8); + + pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n", + regs->r9, regs->r10, regs->r11, regs->r12); + + pr_notice("r13: %08lx r14: %08lx r15: %08lx\n", + regs->r13, regs->r14, regs->r15); + + pr_notice("ra: %08lx fp: %08lx sp: %08lx gp: %08lx\n", + regs->ra, regs->fp, regs->sp, regs->gp); + + pr_notice("ea: %08lx estatus: %08lx\n", + regs->ea, regs->estatus); +} + +void flush_thread(void) +{ + set_fs(USER_DS); +} + +int copy_thread(unsigned long clone_flags, + unsigned long usp, unsigned long arg, struct task_struct *p) +{ + struct pt_regs *childregs = task_pt_regs(p); + struct pt_regs *regs; + struct switch_stack *stack; + struct switch_stack *childstack = + ((struct switch_stack *)childregs) - 1; + + if (unlikely(p->flags & PF_KTHREAD)) { + memset(childstack, 0, + sizeof(struct switch_stack) + sizeof(struct pt_regs)); + + childstack->r16 = usp; /* fn */ + childstack->r17 = arg; + childstack->ra = (unsigned long) ret_from_kernel_thread; + childregs->estatus = STATUS_PIE; + childregs->sp = (unsigned long) childstack; + + p->thread.ksp = (unsigned long) childstack; + p->thread.kregs = childregs; + return 0; + } + + regs = current_pt_regs(); + *childregs = *regs; + childregs->r2 = 0; /* Set the return value for the child. */ + childregs->r7 = 0; + + stack = ((struct switch_stack *) regs) - 1; + *childstack = *stack; + childstack->ra = (unsigned long)ret_from_fork; + p->thread.kregs = childregs; + p->thread.ksp = (unsigned long) childstack; + + if (usp) + childregs->sp = usp; + + /* Initialize tls register. */ + if (clone_flags & CLONE_SETTLS) + childstack->r23 = regs->r8; + + return 0; +} + +/* + * Generic dumping code. Used for panic and debug. + */ +void dump(struct pt_regs *fp) +{ + unsigned long *sp; + unsigned char *tp; + int i; + + pr_emerg("\nCURRENT PROCESS:\n\n"); + pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid); + + if (current->mm) { + pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n", + (int) current->mm->start_code, + (int) current->mm->end_code, + (int) current->mm->start_data, + (int) current->mm->end_data, + (int) current->mm->end_data, + (int) current->mm->brk); + pr_emerg("USER-STACK=%08x KERNEL-STACK=%08x\n\n", + (int) current->mm->start_stack, + (int)(((unsigned long) current) + THREAD_SIZE)); + } + + pr_emerg("PC: %08lx\n", fp->ea); + pr_emerg("SR: %08lx SP: %08lx\n", + (long) fp->estatus, (long) fp); + + pr_emerg("r1: %08lx r2: %08lx r3: %08lx\n", + fp->r1, fp->r2, fp->r3); + + pr_emerg("r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n", + fp->r4, fp->r5, fp->r6, fp->r7); + pr_emerg("r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n", + fp->r8, fp->r9, fp->r10, fp->r11); + pr_emerg("r12: %08lx r13: %08lx r14: %08lx r15: %08lx\n", + fp->r12, fp->r13, fp->r14, fp->r15); + pr_emerg("or2: %08lx ra: %08lx fp: %08lx sp: %08lx\n", + fp->orig_r2, fp->ra, fp->fp, fp->sp); + pr_emerg("\nUSP: %08x TRAPFRAME: %08x\n", + (unsigned int) fp->sp, (unsigned int) fp); + + pr_emerg("\nCODE:"); + tp = ((unsigned char *) fp->ea) - 0x20; + for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) { + if ((i % 0x10) == 0) + pr_emerg("\n%08x: ", (int) (tp + i)); + pr_emerg("%08x ", (int) *sp++); + } + pr_emerg("\n"); + + pr_emerg("\nKERNEL STACK:"); + tp = ((unsigned char *) fp) - 0x40; + for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) { + if ((i % 0x10) == 0) + pr_emerg("\n%08x: ", (int) (tp + i)); + pr_emerg("%08x ", (int) *sp++); + } + pr_emerg("\n"); + pr_emerg("\n"); + + pr_emerg("\nUSER STACK:"); + tp = (unsigned char *) (fp->sp - 0x10); + for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) { + if ((i % 0x10) == 0) + pr_emerg("\n%08x: ", (int) (tp + i)); + pr_emerg("%08x ", (int) *sp++); + } + pr_emerg("\n\n"); +} + +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long fp, pc; + unsigned long stack_page; + int count = 0; + + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + stack_page = (unsigned long)p; + fp = ((struct switch_stack *)p->thread.ksp)->fp; /* ;dgt2 */ + do { + if (fp < stack_page+sizeof(struct task_struct) || + fp >= 8184+stack_page) /* ;dgt2;tmp */ + return 0; + pc = ((unsigned long *)fp)[1]; + if (!in_sched_functions(pc)) + return pc; + fp = *(unsigned long *) fp; + } while (count++ < 16); /* ;dgt2;tmp */ + return 0; +} + +/* + * Do necessary setup to start up a newly executed thread. + * Will startup in user mode (status_extension = 0). + */ +void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp) +{ + memset((void *) regs, 0, sizeof(struct pt_regs)); + regs->estatus = ESTATUS_EPIE | ESTATUS_EU; + regs->ea = pc; + regs->sp = sp; +} + +#include <linux/elfcore.h> + +/* Fill in the FPU structure for a core dump. */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) +{ + return 0; /* Nios2 has no FPU and thus no FPU registers */ +} |