| /* |
| * arch/s390/kernel/process.c |
| * |
| * S390 version |
| * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), |
| * Hartmut Penner (hp@de.ibm.com), |
| * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), |
| * |
| * Derived from "arch/i386/kernel/process.c" |
| * Copyright (C) 1995, Linus Torvalds |
| */ |
| |
| /* |
| * This file handles the architecture-dependent parts of process handling.. |
| */ |
| |
| #define __KERNEL_SYSCALLS__ |
| #include <stdarg.h> |
| |
| #include <linux/config.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/delay.h> |
| #include <linux/reboot.h> |
| #include <linux/init.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/io.h> |
| #include <asm/processor.h> |
| #include <asm/irq.h> |
| |
| asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); |
| |
| /* |
| * The idle loop on a S390... |
| */ |
| |
| int cpu_idle(void *unused) |
| { |
| psw_t wait_psw; |
| unsigned long reg; |
| |
| /* endless idle loop with no priority at all */ |
| init_idle(); |
| current->nice = 20; |
| current->counter = -100; |
| while (1) { |
| __cli(); |
| if (current->need_resched) { |
| __sti(); |
| schedule(); |
| check_pgt_cache(); |
| continue; |
| } |
| |
| /* |
| * Wait for external, I/O or machine check interrupt and |
| * switch of machine check bit after the wait has ended. |
| */ |
| wait_psw.mask = _WAIT_PSW_MASK; |
| asm volatile ( |
| " larl %0,0f\n" |
| " stg %0,8(%1)\n" |
| " lpswe 0(%1)\n" |
| "0: larl %0,1f\n" |
| " stg %0,8(%1)\n" |
| " ni 1(%1),0xf9\n" |
| " lpswe 0(%1)\n" |
| "1:" |
| : "=&a" (reg) : "a" (&wait_psw) : "memory", "cc" ); |
| } |
| } |
| |
| extern void show_registers(struct pt_regs *regs); |
| extern void show_trace(unsigned long *sp); |
| |
| void show_regs(struct pt_regs *regs) |
| { |
| struct task_struct *tsk = current; |
| |
| printk("CPU: %d %s\n", tsk->processor, print_tainted()); |
| printk("Process %s (pid: %d, task: %016lx, ksp: %016lx)\n", |
| current->comm, current->pid, (unsigned long) tsk, |
| tsk->thread.ksp); |
| |
| show_registers(regs); |
| /* Show stack backtrace if pt_regs is from kernel mode */ |
| if (!(regs->psw.mask & PSW_PROBLEM_STATE)) |
| show_trace((unsigned long *) regs->gprs[15]); |
| } |
| |
| int arch_kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) |
| { |
| int clone_arg = flags | CLONE_VM; |
| int retval; |
| |
| __asm__ __volatile__( |
| " slgr 2,2\n" |
| " lgr 3,%1\n" |
| " lg 4,%6\n" /* load kernel stack ptr of parent */ |
| " svc %b2\n" /* Linux system call*/ |
| " clg 4,%6\n" /* compare ksp's: child or parent ? */ |
| " je 0f\n" /* parent - jump*/ |
| " lg 15,%6\n" /* fix kernel stack pointer*/ |
| " aghi 15,%7\n" |
| " xc 0(160,15),0(15)\n" /* clear save area */ |
| " lgr 2,%4\n" /* load argument*/ |
| " basr 14,%5\n" /* call fn*/ |
| " svc %b3\n" /* Linux system call*/ |
| "0: lgr %0,2" |
| : "=a" (retval) |
| : "d" (clone_arg), "i" (__NR_clone), "i" (__NR_exit), |
| "d" (arg), "a" (fn), "i" (__LC_KERNEL_STACK) , |
| "i" (-STACK_FRAME_OVERHEAD) |
| : "2", "3", "4" ); |
| return retval; |
| } |
| |
| /* |
| * Free current thread data structures etc.. |
| */ |
| void exit_thread(void) |
| { |
| } |
| |
| void flush_thread(void) |
| { |
| |
| current->used_math = 0; |
| current->flags &= ~PF_USEDFPU; |
| } |
| |
| void release_thread(struct task_struct *dead_task) |
| { |
| } |
| |
| int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp, |
| unsigned long unused, |
| struct task_struct * p, struct pt_regs * regs) |
| { |
| struct stack_frame |
| { |
| unsigned long back_chain; |
| unsigned long eos; |
| unsigned long glue1; |
| unsigned long glue2; |
| unsigned long scratch[2]; |
| unsigned long gprs[10]; /* gprs 6 -15 */ |
| unsigned long fprs[2]; /* fpr 4 and 6 */ |
| unsigned long empty[2]; |
| struct pt_regs childregs; |
| } *frame; |
| |
| frame = (struct stack_frame *) (4*PAGE_SIZE + (unsigned long) p) -1; |
| p->thread.ksp = (unsigned long) frame; |
| frame->childregs = *regs; |
| frame->childregs.gprs[15] = new_stackp; |
| frame->back_chain = frame->eos = 0; |
| |
| /* new return point is ret_from_sys_call */ |
| frame->gprs[8] = (unsigned long) &ret_from_fork; |
| |
| /* fake return stack for resume(), don't go back to schedule */ |
| frame->gprs[9] = (unsigned long) frame; |
| /* save fprs, if used in last task */ |
| save_fp_regs(&p->thread.fp_regs); |
| p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE; |
| /* start new process with ar4 pointing to the correct address space */ |
| p->thread.ar4 = get_fs().ar4; |
| /* Don't copy debug registers */ |
| memset(&p->thread.per_info,0,sizeof(p->thread.per_info)); |
| return 0; |
| } |
| |
| /* |
| * Allocation and freeing of basic task resources. |
| * The task struct and the stack go together. |
| * |
| * NOTE: An order-2 allocation can easily fail. If this |
| * happens we fall back to using vmalloc ... |
| */ |
| |
| struct task_struct *alloc_task_struct(void) |
| { |
| struct task_struct *tsk = __get_free_pages(GFP_KERNEL, 2); |
| if (!tsk) |
| tsk = vmalloc(16384); |
| if (!tsk) |
| return NULL; |
| |
| atomic_set((atomic_t *)(tsk + 1), 1); |
| return tsk; |
| } |
| |
| void free_task_struct(struct task_struct *tsk) |
| { |
| if (atomic_dec_and_test((atomic_t *)(tsk + 1))) |
| { |
| if ((unsigned long)tsk < VMALLOC_START) |
| free_pages((unsigned long)tsk, 2); |
| else |
| vfree(tsk); |
| } |
| } |
| |
| void get_task_struct(struct task_struct *tsk) |
| { |
| atomic_inc((atomic_t *)(tsk + 1)); |
| } |
| |
| |
| asmlinkage int sys_fork(struct pt_regs regs) |
| { |
| return do_fork(SIGCHLD, regs.gprs[15], ®s, 0); |
| } |
| |
| asmlinkage int sys_clone(struct pt_regs regs) |
| { |
| unsigned long clone_flags; |
| unsigned long newsp; |
| |
| clone_flags = regs.gprs[3]; |
| newsp = regs.orig_gpr2; |
| if (!newsp) |
| newsp = regs.gprs[15]; |
| 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.gprs[15], ®s, 0); |
| } |
| |
| /* |
| * sys_execve() executes a new program. |
| */ |
| asmlinkage int sys_execve(struct pt_regs regs) |
| { |
| int error; |
| char * filename; |
| |
| filename = getname((char *) regs.orig_gpr2); |
| error = PTR_ERR(filename); |
| if (IS_ERR(filename)) |
| goto out; |
| error = do_execve(filename, (char **) regs.gprs[3], (char **) regs.gprs[4], ®s); |
| if (error == 0) |
| { |
| current->ptrace &= ~PT_DTRACE; |
| current->thread.fp_regs.fpc=0; |
| __asm__ __volatile__ |
| ("sr 0,0\n\t" |
| "sfpc 0,0\n\t" |
| : : :"0"); |
| } |
| putname(filename); |
| out: |
| return error; |
| } |
| |
| |
| /* |
| * fill in the FPU structure for a core dump. |
| */ |
| int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) |
| { |
| save_fp_regs(fpregs); |
| return 1; |
| } |
| |
| /* |
| * fill in the user structure for a core dump.. |
| */ |
| void dump_thread(struct pt_regs * regs, struct user * dump) |
| { |
| |
| /* changed the size calculations - should hopefully work better. lbt */ |
| dump->magic = CMAGIC; |
| dump->start_code = 0; |
| dump->start_stack = regs->gprs[15] & ~(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; |
| if (dump->start_stack < TASK_SIZE) |
| dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; |
| memcpy(&dump->regs.gprs[0],regs,sizeof(s390_regs)); |
| dump_fpu (regs, &dump->regs.fp_regs); |
| memcpy(&dump->regs.per_info,¤t->thread.per_info,sizeof(per_struct)); |
| } |
| |
| /* |
| * 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 r14, r15, bc; |
| unsigned long stack_page; |
| int count = 0; |
| if (!p || p == current || p->state == TASK_RUNNING) |
| return 0; |
| stack_page = (unsigned long) p; |
| r15 = p->thread.ksp; |
| if (!stack_page || r15 < stack_page || r15 >= 16380+stack_page) |
| return 0; |
| bc = *(unsigned long *) r15; |
| do { |
| if (bc < stack_page || bc >= 16380+stack_page) |
| return 0; |
| r14 = *(unsigned long *) (bc+112); |
| if (r14 < first_sched || r14 >= last_sched) |
| return r14; |
| bc = *(unsigned long *) bc; |
| } while (count++ < 16); |
| return 0; |
| } |
| #undef last_sched |
| #undef first_sched |
| |