Initial import

1 files changed, 226 insertions, 0 deletions

diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
new file mode 100644
index 000000000..dc5edc29b
--- /dev/null
+++ b/arch/s390/kernel/process.c
@@ -0,0 +1,226 @@
+/*
+ * This file handles the architecture dependent parts of process handling.
+ *
+ *    Copyright IBM Corp. 1999, 2009
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Hartmut Penner <hp@de.ibm.com>,
+ *		 Denis Joseph Barrow,
+ */
+
+#include <linux/compiler.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/elfcore.h>
+#include <linux/smp.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/tick.h>
+#include <linux/personality.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <linux/kprobes.h>
+#include <linux/random.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/vtimer.h>
+#include <asm/exec.h>
+#include <asm/irq.h>
+#include <asm/nmi.h>
+#include <asm/smp.h>
+#include <asm/switch_to.h>
+#include <asm/runtime_instr.h>
+#include "entry.h"
+
+asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
+
+/*
+ * Return saved PC of a blocked thread. used in kernel/sched.
+ * resume in entry.S does not create a new stack frame, it
+ * just stores the registers %r6-%r15 to the frame given by
+ * schedule. We want to return the address of the caller of
+ * schedule, so we have to walk the backchain one time to
+ * find the frame schedule() store its return address.
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+	struct stack_frame *sf, *low, *high;
+
+	if (!tsk || !task_stack_page(tsk))
+		return 0;
+	low = task_stack_page(tsk);
+	high = (struct stack_frame *) task_pt_regs(tsk);
+	sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	return sf->gprs[8];
+}
+
+extern void kernel_thread_starter(void);
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+	exit_thread_runtime_instr();
+}
+
+void flush_thread(void)
+{
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+void arch_release_task_struct(struct task_struct *tsk)
+{
+	if (tsk->thread.vxrs)
+		kfree(tsk->thread.vxrs);
+}
+
+int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
+		unsigned long arg, struct task_struct *p)
+{
+	struct thread_info *ti;
+	struct fake_frame
+	{
+		struct stack_frame sf;
+		struct pt_regs childregs;
+	} *frame;
+
+	frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
+	p->thread.ksp = (unsigned long) frame;
+	/* Save access registers to new thread structure. */
+	save_access_regs(&p->thread.acrs[0]);
+	/* start new process with ar4 pointing to the correct address space */
+	p->thread.mm_segment = get_fs();
+	/* Don't copy debug registers */
+	memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
+	memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
+	clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
+	/* Initialize per thread user and system timer values */
+	ti = task_thread_info(p);
+	ti->user_timer = 0;
+	ti->system_timer = 0;
+
+	frame->sf.back_chain = 0;
+	/* new return point is ret_from_fork */
+	frame->sf.gprs[8] = (unsigned long) ret_from_fork;
+	/* fake return stack for resume(), don't go back to schedule */
+	frame->sf.gprs[9] = (unsigned long) frame;
+
+	/* Store access registers to kernel stack of new process. */
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		/* kernel thread */
+		memset(&frame->childregs, 0, sizeof(struct pt_regs));
+		frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
+				PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+		frame->childregs.psw.addr = PSW_ADDR_AMODE |
+				(unsigned long) kernel_thread_starter;
+		frame->childregs.gprs[9] = new_stackp; /* function */
+		frame->childregs.gprs[10] = arg;
+		frame->childregs.gprs[11] = (unsigned long) do_exit;
+		frame->childregs.orig_gpr2 = -1;
+
+		return 0;
+	}
+	frame->childregs = *current_pt_regs();
+	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */
+	frame->childregs.flags = 0;
+	if (new_stackp)
+		frame->childregs.gprs[15] = new_stackp;
+
+	/* Don't copy runtime instrumentation info */
+	p->thread.ri_cb = NULL;
+	p->thread.ri_signum = 0;
+	frame->childregs.psw.mask &= ~PSW_MASK_RI;
+
+	/* Save the fpu registers to new thread structure. */
+	save_fp_ctl(&p->thread.fp_regs.fpc);
+	save_fp_regs(p->thread.fp_regs.fprs);
+	p->thread.fp_regs.pad = 0;
+	p->thread.vxrs = NULL;
+	/* Set a new TLS ?  */
+	if (clone_flags & CLONE_SETTLS) {
+		unsigned long tls = frame->childregs.gprs[6];
+		if (is_compat_task()) {
+			p->thread.acrs[0] = (unsigned int)tls;
+		} else {
+			p->thread.acrs[0] = (unsigned int)(tls >> 32);
+			p->thread.acrs[1] = (unsigned int)tls;
+		}
+	}
+	return 0;
+}
+
+asmlinkage void execve_tail(void)
+{
+	current->thread.fp_regs.fpc = 0;
+	asm volatile("sfpc %0,%0" : : "d" (0));
+}
+
+/*
+ * fill in the FPU structure for a core dump.
+ */
+int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
+{
+	save_fp_ctl(&fpregs->fpc);
+	save_fp_regs(fpregs->fprs);
+	return 1;
+}
+EXPORT_SYMBOL(dump_fpu);
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	struct stack_frame *sf, *low, *high;
+	unsigned long return_address;
+	int count;
+
+	if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
+		return 0;
+	low = task_stack_page(p);
+	high = (struct stack_frame *) task_pt_regs(p);
+	sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
+	if (sf <= low || sf > high)
+		return 0;
+	for (count = 0; count < 16; count++) {
+		sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
+		if (sf <= low || sf > high)
+			return 0;
+		return_address = sf->gprs[8] & PSW_ADDR_INSN;
+		if (!in_sched_functions(return_address))
+			return return_address;
+	}
+	return 0;
+}
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() & ~PAGE_MASK;
+	return sp & ~0xf;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
+	else
+		return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long ret;
+
+	ret = PAGE_ALIGN(mm->brk + brk_rnd());
+	return (ret > mm->brk) ? ret : mm->brk;
+}