summaryrefslogtreecommitdiff
path: root/arch/nios2/kernel/process.c
diff options
context:
space:
mode:
authorLey Foon Tan <lftan@altera.com>2014-11-06 10:19:47 +0300
committerLey Foon Tan <lftan@altera.com>2014-12-08 07:55:53 +0300
commit71995e4d004f6afbc86cc4a80c4a281f6c00b07f (patch)
tree68139e7bb9dfee02e23384224e2fa20082e55653 /arch/nios2/kernel/process.c
parentcbd15b3fadc27e81a6e8a3d38ce13cde5ce7cb71 (diff)
downloadlinux-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.c258
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 */
+}