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;
+}