diff options
Diffstat (limited to 'xenolinux-2.4.23-sparse/arch/xeno/kernel/process.c')
| -rw-r--r-- | xenolinux-2.4.23-sparse/arch/xeno/kernel/process.c | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/xenolinux-2.4.23-sparse/arch/xeno/kernel/process.c b/xenolinux-2.4.23-sparse/arch/xeno/kernel/process.c new file mode 100644 index 0000000000..3b17c7326c --- /dev/null +++ b/xenolinux-2.4.23-sparse/arch/xeno/kernel/process.c @@ -0,0 +1,489 @@ +/* + * linux/arch/i386/kernel/process.c + * + * Copyright (C) 1995 Linus Torvalds + * + * Pentium III FXSR, SSE support + * Gareth Hughes <gareth@valinux.com>, May 2000 + */ + +/* + * This file handles the architecture-dependent parts of process handling.. + */ + +#define __KERNEL_SYSCALLS__ +#include <stdarg.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/vmalloc.h> +#include <linux/user.h> +#include <linux/a.out.h> +#include <linux/interrupt.h> +#include <linux/config.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/mc146818rtc.h> + +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/io.h> +#include <asm/ldt.h> +#include <asm/processor.h> +#include <asm/i387.h> +#include <asm/desc.h> +#include <asm/mmu_context.h> +#include <asm/multicall.h> +#include <asm/hypervisor-ifs/dom0_ops.h> + +#include <linux/irq.h> + +asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); + +int hlt_counter; + +/* + * Powermanagement idle function, if any.. + */ +void (*pm_idle)(void); + +/* + * Power off function, if any + */ +void (*pm_power_off)(void); + +void disable_hlt(void) +{ + hlt_counter++; +} + +void enable_hlt(void) +{ + hlt_counter--; +} + +/* + * The idle thread. There's no useful work to be + * done, so just try to conserve power and have a + * low exit latency (ie sit in a loop waiting for + * somebody to say that they'd like to reschedule) + */ +void cpu_idle (void) +{ + /* endless idle loop with no priority at all */ + init_idle(); + current->nice = 20; + current->counter = -100; + + while (1) { + while (!current->need_resched) + HYPERVISOR_yield(); + schedule(); + check_pgt_cache(); + } +} + +void machine_restart(char * __unused) +{ + HYPERVISOR_exit(); +} + +void machine_halt(void) +{ + HYPERVISOR_exit(); +} + +void machine_power_off(void) +{ + HYPERVISOR_exit(); +} + +extern void show_trace(unsigned long* esp); + +void show_regs(struct pt_regs * regs) +{ + printk("\n"); + printk("Pid: %d, comm: %20s\n", current->pid, current->comm); + printk("EIP: %04x:[<%08lx>] CPU: %d",0xffff & regs->xcs,regs->eip, smp_processor_id()); + if (regs->xcs & 2) + printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp); + printk(" EFLAGS: %08lx %s\n",regs->eflags, print_tainted()); + printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n", + regs->eax,regs->ebx,regs->ecx,regs->edx); + printk("ESI: %08lx EDI: %08lx EBP: %08lx", + regs->esi, regs->edi, regs->ebp); + printk(" DS: %04x ES: %04x\n", + 0xffff & regs->xds,0xffff & regs->xes); + + show_trace(®s->esp); +} + +/* + * No need to lock the MM as we are the last user + */ +void release_segments(struct mm_struct *mm) +{ + void * ldt = mm->context.segments; + + /* + * free the LDT + */ + if (ldt) { + mm->context.segments = NULL; + clear_LDT(); + make_pages_writeable(ldt, (LDT_ENTRIES*LDT_ENTRY_SIZE)/PAGE_SIZE); + flush_page_update_queue(); + vfree(ldt); + } +} + +/* + * Create a kernel thread + */ +int arch_kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) +{ + long retval, d0; + + __asm__ __volatile__( + "movl %%esp,%%esi\n\t" + "int $0x80\n\t" /* Linux/i386 system call */ + "cmpl %%esp,%%esi\n\t" /* child or parent? */ + "je 1f\n\t" /* parent - jump */ + /* Load the argument into eax, and push it. That way, it does + * not matter whether the called function is compiled with + * -mregparm or not. */ + "movl %4,%%eax\n\t" + "pushl %%eax\n\t" + "call *%5\n\t" /* call fn */ + "movl %3,%0\n\t" /* exit */ + "int $0x80\n" + "1:\t" + :"=&a" (retval), "=&S" (d0) + :"0" (__NR_clone), "i" (__NR_exit), + "r" (arg), "r" (fn), + "b" (flags | CLONE_VM) + : "memory"); + + return retval; +} + +/* + * Free current thread data structures etc.. + */ +void exit_thread(void) +{ + /* nothing to do ... */ +} + +void flush_thread(void) +{ + struct task_struct *tsk = current; + + memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8); + + /* + * Forget coprocessor state.. + */ + clear_fpu(tsk); + tsk->used_math = 0; +} + +void release_thread(struct task_struct *dead_task) +{ + if (dead_task->mm) { + void * ldt = dead_task->mm->context.segments; + + // temporary debugging check + if (ldt) { + printk("WARNING: dead process %8s still has LDT? <%p>\n", + dead_task->comm, ldt); + BUG(); + } + } +} + +/* + * we do not have to muck with descriptors here, that is + * done in switch_mm() as needed. + */ +void copy_segments(struct task_struct *p, struct mm_struct *new_mm) +{ + struct mm_struct * old_mm; + void *old_ldt, *ldt; + + ldt = NULL; + old_mm = current->mm; + if (old_mm && (old_ldt = old_mm->context.segments) != NULL) { + /* + * Completely new LDT, we initialize it from the parent: + */ + ldt = vmalloc(LDT_ENTRIES*LDT_ENTRY_SIZE); + if ( ldt == NULL ) + { + printk(KERN_WARNING "ldt allocation failed\n"); + } + else + { + memcpy(ldt, old_ldt, LDT_ENTRIES*LDT_ENTRY_SIZE); + make_pages_readonly(ldt, (LDT_ENTRIES*LDT_ENTRY_SIZE)/PAGE_SIZE); + } + } + new_mm->context.segments = ldt; + new_mm->context.cpuvalid = ~0UL; /* valid on all CPU's - they can't have stale data */ +} + +/* + * Save a segment. + */ +#define savesegment(seg,value) \ + asm volatile("movl %%" #seg ",%0":"=m" (*(int *)&(value))) + +int copy_thread(int nr, unsigned long clone_flags, unsigned long esp, + unsigned long unused, + struct task_struct * p, struct pt_regs * regs) +{ + struct pt_regs * childregs; + unsigned long eflags; + + childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p)) - 1; + struct_cpy(childregs, regs); + childregs->eax = 0; + childregs->esp = esp; + + p->thread.esp = (unsigned long) childregs; + p->thread.esp0 = (unsigned long) (childregs+1); + + p->thread.eip = (unsigned long) ret_from_fork; + + savesegment(fs,p->thread.fs); + savesegment(gs,p->thread.gs); + + unlazy_fpu(current); + struct_cpy(&p->thread.i387, ¤t->thread.i387); + + + __asm__ __volatile__ ( "pushfl; popl %0" : "=r" (eflags) : ); + p->thread.io_pl = (eflags >> 12) & 3; + + return 0; +} + +/* + * fill in the user structure for a core dump.. + */ +void dump_thread(struct pt_regs * regs, struct user * dump) +{ + int i; + +/* changed the size calculations - should hopefully work better. lbt */ + dump->magic = CMAGIC; + dump->start_code = 0; + dump->start_stack = regs->esp & ~(PAGE_SIZE - 1); + dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; + dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT; + dump->u_dsize -= dump->u_tsize; + dump->u_ssize = 0; + for (i = 0; i < 8; i++) + dump->u_debugreg[i] = current->thread.debugreg[i]; + + if (dump->start_stack < TASK_SIZE) + dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; + + dump->regs.ebx = regs->ebx; + dump->regs.ecx = regs->ecx; + dump->regs.edx = regs->edx; + dump->regs.esi = regs->esi; + dump->regs.edi = regs->edi; + dump->regs.ebp = regs->ebp; + dump->regs.eax = regs->eax; + dump->regs.ds = regs->xds; + dump->regs.es = regs->xes; + savesegment(fs,dump->regs.fs); + savesegment(gs,dump->regs.gs); + dump->regs.orig_eax = regs->orig_eax; + dump->regs.eip = regs->eip; + dump->regs.cs = regs->xcs; + dump->regs.eflags = regs->eflags; + dump->regs.esp = regs->esp; + dump->regs.ss = regs->xss; + + dump->u_fpvalid = dump_fpu (regs, &dump->i387); +} + +/* + * switch_to(x,yn) should switch tasks from x to y. + * + * We fsave/fwait so that an exception goes off at the right time + * (as a call from the fsave or fwait in effect) rather than to + * the wrong process. Lazy FP saving no longer makes any sense + * with modern CPU's, and this simplifies a lot of things (SMP + * and UP become the same). + * + * NOTE! We used to use the x86 hardware context switching. The + * reason for not using it any more becomes apparent when you + * try to recover gracefully from saved state that is no longer + * valid (stale segment register values in particular). With the + * hardware task-switch, there is no way to fix up bad state in + * a reasonable manner. + * + * The fact that Intel documents the hardware task-switching to + * be slow is a fairly red herring - this code is not noticeably + * faster. However, there _is_ some room for improvement here, + * so the performance issues may eventually be a valid point. + * More important, however, is the fact that this allows us much + * more flexibility. + */ +void __switch_to(struct task_struct *prev_p, struct task_struct *next_p) +{ + struct thread_struct *next = &next_p->thread; + + __cli(); + + MULTICALL_flush_page_update_queue(); + + /* + * This is basically 'unlazy_fpu', except that we queue a multicall to + * indicate FPU task switch, rather than synchronously trapping to Xen. + */ + if ( prev_p->flags & PF_USEDFPU ) + { + if ( cpu_has_fxsr ) + asm volatile( "fxsave %0 ; fnclex" + : "=m" (prev_p->thread.i387.fxsave) ); + else + asm volatile( "fnsave %0 ; fwait" + : "=m" (prev_p->thread.i387.fsave) ); + prev_p->flags &= ~PF_USEDFPU; + queue_multicall0(__HYPERVISOR_fpu_taskswitch); + } + + queue_multicall2(__HYPERVISOR_stack_switch, __KERNEL_DS, next->esp0); + if ( start_info.flags & SIF_PRIVILEGED ) + { + dom0_op_t op; + op.cmd = DOM0_IOPL; + op.u.iopl.domain = start_info.dom_id; + op.u.iopl.iopl = next->io_pl; + queue_multicall1(__HYPERVISOR_dom0_op, (unsigned long)&op); + } + + /* EXECUTE ALL TASK SWITCH XEN SYSCALLS AT THIS POINT. */ + execute_multicall_list(); + __sti(); + + /* + * Restore %fs and %gs. + */ + loadsegment(fs, next->fs); + loadsegment(gs, next->gs); + + /* + * Now maybe reload the debug registers + */ + if ( next->debugreg[7] != 0 ) + { + HYPERVISOR_set_debugreg(0, next->debugreg[0]); + HYPERVISOR_set_debugreg(1, next->debugreg[1]); + HYPERVISOR_set_debugreg(2, next->debugreg[2]); + HYPERVISOR_set_debugreg(3, next->debugreg[3]); + /* no 4 and 5 */ + HYPERVISOR_set_debugreg(6, next->debugreg[6]); + HYPERVISOR_set_debugreg(7, next->debugreg[7]); + } +} + +asmlinkage int sys_fork(struct pt_regs regs) +{ + return do_fork(SIGCHLD, regs.esp, ®s, 0); +} + +asmlinkage int sys_clone(struct pt_regs regs) +{ + unsigned long clone_flags; + unsigned long newsp; + + clone_flags = regs.ebx; + newsp = regs.ecx; + if (!newsp) + newsp = regs.esp; + return do_fork(clone_flags, newsp, ®s, 0); +} + +/* + * This is trivial, and on the face of it looks like it + * could equally well be done in user mode. + * + * Not so, for quite unobvious reasons - register pressure. + * In user mode vfork() cannot have a stack frame, and if + * done by calling the "clone()" system call directly, you + * do not have enough call-clobbered registers to hold all + * the information you need. + */ +asmlinkage int sys_vfork(struct pt_regs regs) +{ + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, ®s, 0); +} + +/* + * sys_execve() executes a new program. + */ +asmlinkage int sys_execve(struct pt_regs regs) +{ + int error; + char * filename; + + filename = getname((char *) regs.ebx); + error = PTR_ERR(filename); + if (IS_ERR(filename)) + goto out; + error = do_execve(filename, (char **) regs.ecx, (char **) regs.edx, ®s); + if (error == 0) + current->ptrace &= ~PT_DTRACE; + putname(filename); + out: + return error; +} + +/* + * These bracket the sleeping functions.. + */ +extern void scheduling_functions_start_here(void); +extern void scheduling_functions_end_here(void); +#define first_sched ((unsigned long) scheduling_functions_start_here) +#define last_sched ((unsigned long) scheduling_functions_end_here) + +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long ebp, esp, eip; + unsigned long stack_page; + int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + stack_page = (unsigned long)p; + esp = p->thread.esp; + if (!stack_page || esp < stack_page || esp > 8188+stack_page) + return 0; + /* include/asm-i386/system.h:switch_to() pushes ebp last. */ + ebp = *(unsigned long *) esp; + do { + if (ebp < stack_page || ebp > 8184+stack_page) + return 0; + eip = *(unsigned long *) (ebp+4); + if (eip < first_sched || eip >= last_sched) + return eip; + ebp = *(unsigned long *) ebp; + } while (count++ < 16); + return 0; +} +#undef last_sched +#undef first_sched |