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-rw-r--r--arch/alpha/kernel/process.c528
1 files changed, 528 insertions, 0 deletions
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
new file mode 100644
index 000000000000..4933f3ce5833
--- /dev/null
+++ b/arch/alpha/kernel/process.c
@@ -0,0 +1,528 @@
+/*
+ * linux/arch/alpha/kernel/process.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling.
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/module.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/utsname.h>
+#include <linux/time.h>
+#include <linux/major.h>
+#include <linux/stat.h>
+#include <linux/mman.h>
+#include <linux/elfcore.h>
+#include <linux/reboot.h>
+#include <linux/tty.h>
+#include <linux/console.h>
+
+#include <asm/reg.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/hwrpb.h>
+#include <asm/fpu.h>
+
+#include "proto.h"
+#include "pci_impl.h"
+
+void default_idle(void)
+{
+ barrier();
+}
+
+void
+cpu_idle(void)
+{
+ while (1) {
+ void (*idle)(void) = default_idle;
+ /* FIXME -- EV6 and LCA45 know how to power down
+ the CPU. */
+
+ while (!need_resched())
+ idle();
+ schedule();
+ }
+}
+
+
+struct halt_info {
+ int mode;
+ char *restart_cmd;
+};
+
+static void
+common_shutdown_1(void *generic_ptr)
+{
+ struct halt_info *how = (struct halt_info *)generic_ptr;
+ struct percpu_struct *cpup;
+ unsigned long *pflags, flags;
+ int cpuid = smp_processor_id();
+
+ /* No point in taking interrupts anymore. */
+ local_irq_disable();
+
+ cpup = (struct percpu_struct *)
+ ((unsigned long)hwrpb + hwrpb->processor_offset
+ + hwrpb->processor_size * cpuid);
+ pflags = &cpup->flags;
+ flags = *pflags;
+
+ /* Clear reason to "default"; clear "bootstrap in progress". */
+ flags &= ~0x00ff0001UL;
+
+#ifdef CONFIG_SMP
+ /* Secondaries halt here. */
+ if (cpuid != boot_cpuid) {
+ flags |= 0x00040000UL; /* "remain halted" */
+ *pflags = flags;
+ clear_bit(cpuid, &cpu_present_mask);
+ halt();
+ }
+#endif
+
+ if (how->mode == LINUX_REBOOT_CMD_RESTART) {
+ if (!how->restart_cmd) {
+ flags |= 0x00020000UL; /* "cold bootstrap" */
+ } else {
+ /* For SRM, we could probably set environment
+ variables to get this to work. We'd have to
+ delay this until after srm_paging_stop unless
+ we ever got srm_fixup working.
+
+ At the moment, SRM will use the last boot device,
+ but the file and flags will be the defaults, when
+ doing a "warm" bootstrap. */
+ flags |= 0x00030000UL; /* "warm bootstrap" */
+ }
+ } else {
+ flags |= 0x00040000UL; /* "remain halted" */
+ }
+ *pflags = flags;
+
+#ifdef CONFIG_SMP
+ /* Wait for the secondaries to halt. */
+ cpu_clear(boot_cpuid, cpu_possible_map);
+ while (cpus_weight(cpu_possible_map))
+ barrier();
+#endif
+
+ /* If booted from SRM, reset some of the original environment. */
+ if (alpha_using_srm) {
+#ifdef CONFIG_DUMMY_CONSOLE
+ /* This has the effect of resetting the VGA video origin. */
+ take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
+#endif
+ pci_restore_srm_config();
+ set_hae(srm_hae);
+ }
+
+ if (alpha_mv.kill_arch)
+ alpha_mv.kill_arch(how->mode);
+
+ if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
+ /* Unfortunately, since MILO doesn't currently understand
+ the hwrpb bits above, we can't reliably halt the
+ processor and keep it halted. So just loop. */
+ return;
+ }
+
+ if (alpha_using_srm)
+ srm_paging_stop();
+
+ halt();
+}
+
+static void
+common_shutdown(int mode, char *restart_cmd)
+{
+ struct halt_info args;
+ args.mode = mode;
+ args.restart_cmd = restart_cmd;
+ on_each_cpu(common_shutdown_1, &args, 1, 0);
+}
+
+void
+machine_restart(char *restart_cmd)
+{
+ common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
+}
+
+EXPORT_SYMBOL(machine_restart);
+
+void
+machine_halt(void)
+{
+ common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
+}
+
+EXPORT_SYMBOL(machine_halt);
+
+void
+machine_power_off(void)
+{
+ common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
+}
+
+EXPORT_SYMBOL(machine_power_off);
+
+/* Used by sysrq-p, among others. I don't believe r9-r15 are ever
+ saved in the context it's used. */
+
+void
+show_regs(struct pt_regs *regs)
+{
+ dik_show_regs(regs, NULL);
+}
+
+/*
+ * Re-start a thread when doing execve()
+ */
+void
+start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
+{
+ set_fs(USER_DS);
+ regs->pc = pc;
+ regs->ps = 8;
+ wrusp(sp);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void
+exit_thread(void)
+{
+}
+
+void
+flush_thread(void)
+{
+ /* Arrange for each exec'ed process to start off with a clean slate
+ with respect to the FPU. This is all exceptions disabled. */
+ current_thread_info()->ieee_state = 0;
+ wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));
+
+ /* Clean slate for TLS. */
+ current_thread_info()->pcb.unique = 0;
+}
+
+void
+release_thread(struct task_struct *dead_task)
+{
+}
+
+/*
+ * "alpha_clone()".. 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)
+ *
+ * Notice that "fork()" is implemented in terms of clone,
+ * with parameters (SIGCHLD, 0).
+ */
+int
+alpha_clone(unsigned long clone_flags, unsigned long usp,
+ int __user *parent_tid, int __user *child_tid,
+ unsigned long tls_value, struct pt_regs *regs)
+{
+ if (!usp)
+ usp = rdusp();
+
+ return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
+}
+
+int
+alpha_vfork(struct pt_regs *regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(),
+ regs, 0, NULL, NULL);
+}
+
+/*
+ * Copy an alpha thread..
+ *
+ * Note the "stack_offset" stuff: when returning to kernel mode, we need
+ * to have some extra stack-space for the kernel stack that still exists
+ * after the "ret_from_fork". When returning to user mode, we only want
+ * the space needed by the syscall stack frame (ie "struct pt_regs").
+ * Use the passed "regs" pointer to determine how much space we need
+ * for a kernel fork().
+ */
+
+int
+copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+ unsigned long unused,
+ struct task_struct * p, struct pt_regs * regs)
+{
+ extern void ret_from_fork(void);
+
+ struct thread_info *childti = p->thread_info;
+ struct pt_regs * childregs;
+ struct switch_stack * childstack, *stack;
+ unsigned long stack_offset, settls;
+
+ stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
+ if (!(regs->ps & 8))
+ stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
+ childregs = (struct pt_regs *)
+ (stack_offset + PAGE_SIZE + (long) childti);
+
+ *childregs = *regs;
+ settls = regs->r20;
+ childregs->r0 = 0;
+ childregs->r19 = 0;
+ childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
+ regs->r20 = 0;
+ stack = ((struct switch_stack *) regs) - 1;
+ childstack = ((struct switch_stack *) childregs) - 1;
+ *childstack = *stack;
+ childstack->r26 = (unsigned long) ret_from_fork;
+ childti->pcb.usp = usp;
+ childti->pcb.ksp = (unsigned long) childstack;
+ childti->pcb.flags = 1; /* set FEN, clear everything else */
+
+ /* Set a new TLS for the child thread? Peek back into the
+ syscall arguments that we saved on syscall entry. Oops,
+ except we'd have clobbered it with the parent/child set
+ of r20. Read the saved copy. */
+ /* Note: if CLONE_SETTLS is not set, then we must inherit the
+ value from the parent, which will have been set by the block
+ copy in dup_task_struct. This is non-intuitive, but is
+ required for proper operation in the case of a threaded
+ application calling fork. */
+ if (clone_flags & CLONE_SETTLS)
+ childti->pcb.unique = settls;
+
+ return 0;
+}
+
+/*
+ * Fill in the user structure for an ECOFF core dump.
+ */
+void
+dump_thread(struct pt_regs * pt, struct user * dump)
+{
+ /* switch stack follows right below pt_regs: */
+ struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
+
+ dump->magic = CMAGIC;
+ dump->start_code = current->mm->start_code;
+ dump->start_data = current->mm->start_data;
+ dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
+ dump->u_tsize = ((current->mm->end_code - dump->start_code)
+ >> PAGE_SHIFT);
+ dump->u_dsize = ((current->mm->brk + PAGE_SIZE-1 - dump->start_data)
+ >> PAGE_SHIFT);
+ dump->u_ssize = (current->mm->start_stack - dump->start_stack
+ + PAGE_SIZE-1) >> PAGE_SHIFT;
+
+ /*
+ * We store the registers in an order/format that is
+ * compatible with DEC Unix/OSF/1 as this makes life easier
+ * for gdb.
+ */
+ dump->regs[EF_V0] = pt->r0;
+ dump->regs[EF_T0] = pt->r1;
+ dump->regs[EF_T1] = pt->r2;
+ dump->regs[EF_T2] = pt->r3;
+ dump->regs[EF_T3] = pt->r4;
+ dump->regs[EF_T4] = pt->r5;
+ dump->regs[EF_T5] = pt->r6;
+ dump->regs[EF_T6] = pt->r7;
+ dump->regs[EF_T7] = pt->r8;
+ dump->regs[EF_S0] = sw->r9;
+ dump->regs[EF_S1] = sw->r10;
+ dump->regs[EF_S2] = sw->r11;
+ dump->regs[EF_S3] = sw->r12;
+ dump->regs[EF_S4] = sw->r13;
+ dump->regs[EF_S5] = sw->r14;
+ dump->regs[EF_S6] = sw->r15;
+ dump->regs[EF_A3] = pt->r19;
+ dump->regs[EF_A4] = pt->r20;
+ dump->regs[EF_A5] = pt->r21;
+ dump->regs[EF_T8] = pt->r22;
+ dump->regs[EF_T9] = pt->r23;
+ dump->regs[EF_T10] = pt->r24;
+ dump->regs[EF_T11] = pt->r25;
+ dump->regs[EF_RA] = pt->r26;
+ dump->regs[EF_T12] = pt->r27;
+ dump->regs[EF_AT] = pt->r28;
+ dump->regs[EF_SP] = rdusp();
+ dump->regs[EF_PS] = pt->ps;
+ dump->regs[EF_PC] = pt->pc;
+ dump->regs[EF_GP] = pt->gp;
+ dump->regs[EF_A0] = pt->r16;
+ dump->regs[EF_A1] = pt->r17;
+ dump->regs[EF_A2] = pt->r18;
+ memcpy((char *)dump->regs + EF_SIZE, sw->fp, 32 * 8);
+}
+
+/*
+ * Fill in the user structure for a ELF core dump.
+ */
+void
+dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti)
+{
+ /* switch stack follows right below pt_regs: */
+ struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
+
+ dest[ 0] = pt->r0;
+ dest[ 1] = pt->r1;
+ dest[ 2] = pt->r2;
+ dest[ 3] = pt->r3;
+ dest[ 4] = pt->r4;
+ dest[ 5] = pt->r5;
+ dest[ 6] = pt->r6;
+ dest[ 7] = pt->r7;
+ dest[ 8] = pt->r8;
+ dest[ 9] = sw->r9;
+ dest[10] = sw->r10;
+ dest[11] = sw->r11;
+ dest[12] = sw->r12;
+ dest[13] = sw->r13;
+ dest[14] = sw->r14;
+ dest[15] = sw->r15;
+ dest[16] = pt->r16;
+ dest[17] = pt->r17;
+ dest[18] = pt->r18;
+ dest[19] = pt->r19;
+ dest[20] = pt->r20;
+ dest[21] = pt->r21;
+ dest[22] = pt->r22;
+ dest[23] = pt->r23;
+ dest[24] = pt->r24;
+ dest[25] = pt->r25;
+ dest[26] = pt->r26;
+ dest[27] = pt->r27;
+ dest[28] = pt->r28;
+ dest[29] = pt->gp;
+ dest[30] = rdusp();
+ dest[31] = pt->pc;
+
+ /* Once upon a time this was the PS value. Which is stupid
+ since that is always 8 for usermode. Usurped for the more
+ useful value of the thread's UNIQUE field. */
+ dest[32] = ti->pcb.unique;
+}
+
+int
+dump_elf_task(elf_greg_t *dest, struct task_struct *task)
+{
+ struct thread_info *ti;
+ struct pt_regs *pt;
+
+ ti = task->thread_info;
+ pt = (struct pt_regs *)((unsigned long)ti + 2*PAGE_SIZE) - 1;
+
+ dump_elf_thread(dest, pt, ti);
+
+ return 1;
+}
+
+int
+dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
+{
+ struct thread_info *ti;
+ struct pt_regs *pt;
+ struct switch_stack *sw;
+
+ ti = task->thread_info;
+ pt = (struct pt_regs *)((unsigned long)ti + 2*PAGE_SIZE) - 1;
+ sw = (struct switch_stack *)pt - 1;
+
+ memcpy(dest, sw->fp, 32 * 8);
+
+ return 1;
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int
+do_sys_execve(char __user *ufilename, char __user * __user *argv,
+ char __user * __user *envp, struct pt_regs *regs)
+{
+ int error;
+ char *filename;
+
+ filename = getname(ufilename);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ goto out;
+ error = do_execve(filename, argv, envp, regs);
+ putname(filename);
+out:
+ return error;
+}
+
+/*
+ * Return saved PC of a blocked thread. This assumes the frame
+ * pointer is the 6th saved long on the kernel stack and that the
+ * saved return address is the first long in the frame. This all
+ * holds provided the thread blocked through a call to schedule() ($15
+ * is the frame pointer in schedule() and $15 is saved at offset 48 by
+ * entry.S:do_switch_stack).
+ *
+ * Under heavy swap load I've seen this lose in an ugly way. So do
+ * some extra sanity checking on the ranges we expect these pointers
+ * to be in so that we can fail gracefully. This is just for ps after
+ * all. -- r~
+ */
+
+unsigned long
+thread_saved_pc(task_t *t)
+{
+ unsigned long base = (unsigned long)t->thread_info;
+ unsigned long fp, sp = t->thread_info->pcb.ksp;
+
+ if (sp > base && sp+6*8 < base + 16*1024) {
+ fp = ((unsigned long*)sp)[6];
+ if (fp > sp && fp < base + 16*1024)
+ return *(unsigned long *)fp;
+ }
+
+ return 0;
+}
+
+unsigned long
+get_wchan(struct task_struct *p)
+{
+ unsigned long schedule_frame;
+ unsigned long pc;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+ /*
+ * This one depends on the frame size of schedule(). Do a
+ * "disass schedule" in gdb to find the frame size. Also, the
+ * code assumes that sleep_on() follows immediately after
+ * interruptible_sleep_on() and that add_timer() follows
+ * immediately after interruptible_sleep(). Ugly, isn't it?
+ * Maybe adding a wchan field to task_struct would be better,
+ * after all...
+ */
+
+ pc = thread_saved_pc(p);
+ if (in_sched_functions(pc)) {
+ schedule_frame = ((unsigned long *)p->thread_info->pcb.ksp)[6];
+ return ((unsigned long *)schedule_frame)[12];
+ }
+ return pc;
+}