--- /dev/null
+/*
+ * arch/ubicom32/kernel/process.c
+ * Ubicom32 architecture-dependent process handling.
+ *
+ * (C) Copyright 2009, Ubicom, Inc.
+ * Copyright (C) 1995 Hamish Macdonald
+ *
+ * 68060 fixes by Jesper Skov
+ *
+ * uClinux changes
+ * Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
+ *
+ * This file is part of the Ubicom32 Linux Kernel Port.
+ *
+ * The Ubicom32 Linux Kernel Port is free software: you can redistribute
+ * it and/or modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * The Ubicom32 Linux Kernel Port is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the Ubicom32 Linux Kernel Port. If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Ubicom32 implementation derived from (with many thanks):
+ * arch/m68knommu
+ * arch/blackfin
+ * arch/parisc
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/reboot.h>
+#include <linux/fs.h>
+#include <linux/pm.h>
+
+#include <linux/uaccess.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/machdep.h>
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+#include <asm/ip5000.h>
+#include <asm/range-protect.h>
+
+#define DUMP_RANGE_REGISTER(REG, IDX) asm volatile ( \
+ " move.4 %0, "REG"_RANGE"IDX"_EN \n\t" \
+ " move.4 %1, "REG"_RANGE"IDX"_LO \n\t" \
+ " move.4 %2, "REG"_RANGE"IDX"_HI \n\t" \
+ : "=d"(en), "=d"(lo), "=d"(hi) \
+ ); \
+ printk(KERN_NOTICE REG"Range"IDX": en:%08x, range: %08x-%08x\n", \
+ (unsigned int)en, \
+ (unsigned int)lo, \
+ (unsigned int)hi)
+
+asmlinkage void ret_from_fork(void);
+
+void (*pm_power_off)(void) = machine_power_off;
+EXPORT_SYMBOL(pm_power_off);
+
+/* machine-dependent / hardware-specific power functions */
+void (*mach_reset)(void);
+void (*mach_halt)(void);
+void (*mach_power_off)(void);
+
+/*
+ * cpu_idle()
+ * The idle thread.
+ *
+ * Our idle loop suspends and is woken up by a timer interrupt.
+ */
+void cpu_idle(void)
+{
+ while (1) {
+ local_irq_disable();
+ while (!need_resched()) {
+ local_irq_enable();
+ thread_suspend();
+ local_irq_disable();
+ }
+ local_irq_enable();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+/*
+ * dump_fpu()
+ *
+ * Fill in the fpu structure for a core dump. (just a stub as we don't have
+ * an fpu)
+ */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
+{
+ return 1;
+}
+
+/*
+ * machine_restart()
+ * Resets the system.
+ */
+void machine_restart(char *__unused)
+{
+ /*
+ * Disable all threads except myself. We can do this
+ * directly without needing to call smp_send_stop
+ * because we have a unique architecture where
+ * one thread can disable one or more other threads.
+ */
+ thread_disable_others();
+
+ /*
+ * Call the hardware-specific machine reset function.
+ */
+ if (mach_reset) {
+ mach_reset();
+ }
+
+ printk(KERN_EMERG "System Restarting\n");
+
+ /*
+ * Set watchdog to trigger (after 1ms delay) (12 Mhz is the fixed OSC)
+ */
+ UBICOM32_IO_TIMER->tkey = TIMER_TKEYVAL;
+ UBICOM32_IO_TIMER->wdcom = UBICOM32_IO_TIMER->mptval +
+ (12000000 / 1000);
+ UBICOM32_IO_TIMER->wdcfg = 0;
+ UBICOM32_IO_TIMER->tkey = 0;
+
+ /*
+ * Wait for watchdog
+ */
+ asm volatile (
+ " move.4 MT_EN, #0 \n\t"
+ " pipe_flush 0 \n\t"
+ );
+
+ local_irq_disable();
+ for (;;) {
+ thread_suspend();
+ }
+}
+
+/*
+ * machine_halt()
+ * Halt the machine.
+ *
+ * Similar to machine_power_off, but don't shut off power. Add code
+ * here to freeze the system for e.g. post-mortem debug purpose when
+ * possible. This halt has nothing to do with the idle halt.
+ */
+void machine_halt(void)
+{
+ /*
+ * Disable all threads except myself. We can do this
+ * directly without needing to call smp_send_stop
+ * because we have a unique architecture where
+ * one thread can disable one or more other threads.
+ */
+ thread_disable_others();
+
+ /*
+ * Call the hardware-specific machine halt function.
+ */
+ if (mach_halt) {
+ mach_halt();
+ }
+
+ printk(KERN_EMERG "System Halted, OK to turn off power\n");
+ local_irq_disable();
+ for (;;) {
+ thread_suspend();
+ }
+}
+
+/*
+ * machine_power_off()
+ * Turn the power off, if a power off handler is defined, otherwise, spin
+ * endlessly.
+ */
+void machine_power_off(void)
+{
+ /*
+ * Disable all threads except myself. We can do this
+ * directly without needing to call smp_send_stop
+ * because we have a unique architecture where
+ * one thread can disable one or more other threads.
+ */
+ thread_disable_others();
+
+ /*
+ * Call the hardware-specific machine power off function.
+ */
+ if (mach_power_off) {
+ mach_power_off();
+ }
+
+ printk(KERN_EMERG "System Halted, OK to turn off power\n");
+ local_irq_disable();
+ for (;;) {
+ thread_suspend();
+ }
+}
+
+/*
+ * address_is_valid()
+ * check if an address is valid -- (for read access)
+ */
+static bool address_is_valid(const void *address)
+{
+ int addr = (int)address;
+ unsigned long socm, eocm, sdram, edram;
+
+ if (addr & 3)
+ return false;
+
+ processor_ocm(&socm, &eocm);
+ processor_dram(&sdram, &edram);
+ if (addr >= socm && addr < eocm)
+ return true;
+
+ if (addr >= sdram && addr < edram)
+ return true;
+
+ return false;
+}
+
+/*
+ * vma_path_name_is_valid()
+ * check if path_name of a vma is a valid string
+ */
+static bool vma_path_name_is_valid(const char *str)
+{
+#define MAX_NAME_LEN 256
+ int i = 0;
+ if (!address_is_valid(str))
+ return false;
+
+ for (; i < MAX_NAME_LEN; i++, str++) {
+ if (*str == '\0')
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * show_vmas()
+ * show vma info of a process
+ */
+void show_vmas(struct task_struct *task)
+{
+#ifdef CONFIG_DEBUG_VERBOSE
+#define UBICOM32_MAX_VMA_COUNT 1024
+
+ struct vm_area_struct *vma;
+ struct file *file;
+ char *name = "";
+ int flags, loop = 0;
+
+ printk(KERN_NOTICE "Start of vma list\n");
+
+ if (!address_is_valid(task) || !address_is_valid(task->mm))
+ goto error;
+
+ vma = task->mm->mmap;
+ while (vma) {
+ if (!address_is_valid(vma))
+ goto error;
+
+ flags = vma->vm_flags;
+ file = vma->vm_file;
+
+ if (file) {
+ /* seems better to use dentry op here, but sanity check is easier this way */
+ if (!address_is_valid(file) || !address_is_valid(file->f_path.dentry) || !vma_path_name_is_valid(file->f_path.dentry->d_name.name))
+ goto error;
+
+ name = (char *)file->f_path.dentry->d_name.name;
+ }
+
+ /* Similar to /proc/pid/maps format */
+ printk(KERN_NOTICE "%08lx-%08lx %c%c%c%c %08lx %s\n",
+ vma->vm_start,
+ vma->vm_end,
+ flags & VM_READ ? 'r' : '-',
+ flags & VM_WRITE ? 'w' : '-',
+ flags & VM_EXEC ? 'x' : '-',
+ flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
+ vma->vm_pgoff << PAGE_SHIFT,
+ name);
+
+ vma = vma->vm_next;
+
+ if (loop++ > UBICOM32_MAX_VMA_COUNT)
+ goto error;
+ }
+
+ printk(KERN_NOTICE "End of vma list\n");
+ return;
+
+error:
+ printk(KERN_NOTICE "\nCorrupted vma list, abort!\n");
+#endif
+}
+
+/*
+ * show_regs()
+ * Print out all of the registers.
+ */
+void show_regs(struct pt_regs *regs)
+{
+ unsigned int i;
+ unsigned int en, lo, hi;
+
+ printk(KERN_NOTICE "regs: %p, tid: %d\n",
+ (void *)regs,
+ thread_get_self());
+
+ printk(KERN_NOTICE "pc: %08x, previous_pc: %08x\n\n",
+ (unsigned int)regs->pc,
+ (unsigned int)regs->previous_pc);
+
+ printk(KERN_NOTICE "Data registers\n");
+ for (i = 0; i < 16; i++) {
+ printk("D%02d: %08x, ", i, (unsigned int)regs->dn[i]);
+ if ((i % 4) == 3) {
+ printk("\n");
+ }
+ }
+ printk("\n");
+
+ printk(KERN_NOTICE "Address registers\n");
+ for (i = 0; i < 8; i++) {
+ printk("A%02d: %08x, ", i, (unsigned int)regs->an[i]);
+ if ((i % 4) == 3) {
+ printk("\n");
+ }
+ }
+ printk("\n");
+
+ printk(KERN_NOTICE "acc0: %08x-%08x, acc1: %08x-%08x\n",
+ (unsigned int)regs->acc0[1],
+ (unsigned int)regs->acc0[0],
+ (unsigned int)regs->acc1[1],
+ (unsigned int)regs->acc1[0]);
+
+ printk(KERN_NOTICE "mac_rc16: %08x, source3: %08x\n",
+ (unsigned int)regs->mac_rc16,
+ (unsigned int)regs->source3);
+
+ printk(KERN_NOTICE "inst_cnt: %08x, csr: %08x\n",
+ (unsigned int)regs->inst_cnt,
+ (unsigned int)regs->csr);
+
+ printk(KERN_NOTICE "int_mask0: %08x, int_mask1: %08x\n",
+ (unsigned int)regs->int_mask0,
+ (unsigned int)regs->int_mask1);
+
+ /*
+ * Dump range registers
+ */
+ DUMP_RANGE_REGISTER("I", "0");
+ DUMP_RANGE_REGISTER("I", "1");
+ DUMP_RANGE_REGISTER("I", "2");
+ DUMP_RANGE_REGISTER("I", "3");
+ DUMP_RANGE_REGISTER("D", "0");
+ DUMP_RANGE_REGISTER("D", "1");
+ DUMP_RANGE_REGISTER("D", "2");
+ DUMP_RANGE_REGISTER("D", "3");
+ DUMP_RANGE_REGISTER("D", "4");
+
+ printk(KERN_NOTICE "frame_type: %d, nesting_level: %d, thread_type %d\n\n",
+ (int)regs->frame_type,
+ (int)regs->nesting_level,
+ (int)regs->thread_type);
+}
+
+/*
+ * kernel_thread_helper()
+ * On execution d0 will be 0, d1 will be the argument to be passed to the
+ * kernel function. d2 contains the kernel function that needs to get
+ * called. d3 will contain address to do_exit which need to get moved
+ * into a5. On return from fork the child thread d0 will be 0. We call
+ * this dummy function which in turn loads the argument
+ */
+asmlinkage void kernel_thread_helper(void);
+
+/*
+ * kernel_thread()
+ * Create a kernel thread
+ */
+int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(®s, 0, sizeof(regs));
+
+ regs.dn[1] = (unsigned long)arg;
+ regs.dn[2] = (unsigned long)fn;
+ regs.dn[3] = (unsigned long)do_exit;
+ regs.an[5] = (unsigned long)kernel_thread_helper;
+ regs.pc = (unsigned long)kernel_thread_helper;
+ regs.nesting_level = 0;
+ regs.thread_type = KERNEL_THREAD;
+
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
+ 0, ®s, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * flush_thread()
+ * XXX todo
+ */
+void flush_thread(void)
+{
+ /* XXX todo */
+}
+
+/*
+ * sys_fork()
+ * Not implemented on no-mmu.
+ */
+asmlinkage int sys_fork(struct pt_regs *regs)
+{
+ /* fork almost works, enough to trick you into looking elsewhere :-( */
+ return -EINVAL;
+}
+
+/*
+ * sys_vfork()
+ * By the time we get here, the non-volatile registers have also been saved
+ * on the stack. We do some ugly pointer stuff here.. (see also copy_thread
+ * which does context copy).
+ */
+asmlinkage int sys_vfork(struct pt_regs *regs)
+{
+ unsigned long old_sp = regs->an[7];
+ unsigned long old_a5 = regs->an[5];
+ unsigned long old_return_address;
+ long do_fork_return;
+
+ /*
+ * Read the old retrun address from the stack.
+ */
+ if (copy_from_user(&old_return_address,
+ (void *)old_sp, sizeof(unsigned long))) {
+ force_sig(SIGSEGV, current);
+ return 0;
+ }
+
+ /*
+ * Pop the vfork call frame by setting a5 and pc to the old_return
+ * address and incrementing the stack pointer by 4.
+ */
+ regs->an[5] = old_return_address;
+ regs->pc = old_return_address;
+ regs->an[7] += 4;
+
+ do_fork_return = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
+ regs->an[7], regs, 0, NULL, NULL);
+
+ /*
+ * Now we have to test if the return code is an error. If it is an error
+ * then restore the frame and we will execute error processing in user
+ * space. Other wise the child and the parent will return to the correct
+ * places.
+ */
+ if ((unsigned long)(do_fork_return) >= (unsigned long)(-125)) {
+ /*
+ * Error case. We need to restore the frame.
+ */
+ regs->an[5] = old_a5;
+ regs->pc = old_a5;
+ regs->an[7] = old_sp;
+ }
+
+ return do_fork_return;
+}
+
+/*
+ * sys_clone()
+ * creates a child thread.
+ */
+asmlinkage int sys_clone(unsigned long clone_flags,
+ unsigned long newsp,
+ struct pt_regs *regs)
+{
+ if (!newsp)
+ newsp = regs->an[7];
+ return do_fork(clone_flags, newsp, regs, 0,
+ NULL, NULL);
+}
+
+/*
+ * copy_thread()
+ * low level thread copy, only used by do_fork in kernel/fork.c
+ */
+int copy_thread(unsigned long clone_flags,
+ unsigned long usp, unsigned long topstk,
+ struct task_struct *p, struct pt_regs *regs)
+
+{
+ struct pt_regs *childregs;
+
+ childregs = (struct pt_regs *)
+ (task_stack_page(p) + THREAD_SIZE - 8) - 1;
+
+ *childregs = *regs;
+
+ /*
+ * Set return value for child to be 0.
+ */
+ childregs->dn[0] = 0;
+
+ if (usp)
+ childregs->an[7] = usp;
+ else
+ childregs->an[7] = (unsigned long)task_stack_page(p) +
+ THREAD_SIZE - 8;
+
+ /*
+ * Set up the switch_to frame to return to "ret_from_fork"
+ */
+ p->thread.a5 = (unsigned long)ret_from_fork;
+ p->thread.sp = (unsigned long)childregs;
+
+ return 0;
+}
+
+/*
+ * sys_execve()
+ * executes a new program.
+ */
+asmlinkage int sys_execve(char *name, char **argv,
+ char **envp, struct pt_regs *regs)
+{
+ int error;
+ char *filename;
+
+ lock_kernel();
+ filename = getname(name);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ goto out;
+ error = do_execve(filename, argv, envp, regs);
+ putname(filename);
+ asm (" .global sys_execve_complete\n"
+ " sys_execve_complete:");
+out:
+ unlock_kernel();
+ return error;
+}
+
+/*
+ * Return saved PC of a blocked thread.
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+ return tsk->thread.a5;
+}
+
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long pc;
+
+ /*
+ * If we don't have a process, or it is not the current
+ * one or not RUNNING, it makes no sense to ask for a
+ * wchan.
+ */
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ /*
+ * TODO: If the process is in the middle of schedule, we
+ * are supposed to do something different but for now we
+ * will return the same thing in both situations.
+ */
+ pc = thread_saved_pc(p);
+ if (in_sched_functions(pc))
+ return pc;
+ return pc;
+}
+
+
+/*
+ * Infrequently used interface to dump task registers to core files.
+ */
+int dump_task_regs(struct task_struct *task, elf_gregset_t *elfregs)
+{
+ struct pt_regs *regs = task_pt_regs(task);
+ *(struct pt_regs *)elfregs = *regs;
+
+ return 1;
+}
+
+/*
+ * __switch_to is the function that implements the contex save and
+ * switch within the kernel. Since this is a function call very few
+ * registers have to be saved to pull this off. d0 holds prev and we
+ * want to preserve it. prev_switch is a pointer to task->thread
+ * structure. This is where we will save the register state. next_switch
+ * is pointer to the next task's thread structure that holds the
+ * registers.
+ */
+asmlinkage void *__switch_to(struct task_struct *prev,
+ struct thread_struct *prev_switch,
+ struct thread_struct *next_switch)
+ __attribute__((naked));
projects / openwrt / svn-archive / archive.git / blobdiff