aha/include/asm-um/processor-generic.h
Jeff Dike 536788fe2d uml: runtime host VMSPLIT detection
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is
needed on i386 if UML is to run on hosts with varying VMSPLITs without
recompilation.

TASK_SIZE is now defined in terms of a variable, task_size.  This gets rid of
an include of pgtable.h from processor.h, which can cause include loops.

On i386, task_size is calculated early in boot by probing the address space in
a binary search to figure out where the boundary between usable and non-usable
memory is.  This tries to make sure that a page that is considered to be in
userspace is, or can be made, read-write.  I'm concerned about a system-global
VDSO page in kernel memory being hit and considered to be a userspace page.

On x86_64, task_size is just the old value of CONFIG_TOP_ADDR.

A bunch of config variable are gone now.  CONFIG_TOP_ADDR is directly replaced
by TASK_SIZE.  NEST_LEVEL is gone since the relocation of the stubs makes it
irrelevant.  All the HOST_VMSPLIT stuff is gone.  All references to these in
arch/um/Makefile are also gone.

I noticed and fixed a missing extern in os.h when adding os_get_task_size.

Note: This has been revised to fix the 32-bit UML on 64-bit host bug that
Miklos ran into.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00

136 lines
2.8 KiB
C

/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#ifndef __UM_PROCESSOR_GENERIC_H
#define __UM_PROCESSOR_GENERIC_H
struct pt_regs;
struct task_struct;
#include "asm/ptrace.h"
#include "registers.h"
#include "sysdep/archsetjmp.h"
struct mm_struct;
struct thread_struct {
struct task_struct *saved_task;
/*
* This flag is set to 1 before calling do_fork (and analyzed in
* copy_thread) to mark that we are begin called from userspace (fork /
* vfork / clone), and reset to 0 after. It is left to 0 when called
* from kernelspace (i.e. kernel_thread() or fork_idle(),
* as of 2.6.11).
*/
int forking;
struct pt_regs regs;
int singlestep_syscall;
void *fault_addr;
jmp_buf *fault_catcher;
struct task_struct *prev_sched;
unsigned long temp_stack;
jmp_buf *exec_buf;
struct arch_thread arch;
jmp_buf switch_buf;
int mm_count;
struct {
int op;
union {
struct {
int pid;
} fork, exec;
struct {
int (*proc)(void *);
void *arg;
} thread;
struct {
void (*proc)(void *);
void *arg;
} cb;
} u;
} request;
};
#define INIT_THREAD \
{ \
.forking = 0, \
.regs = EMPTY_REGS, \
.fault_addr = NULL, \
.prev_sched = NULL, \
.temp_stack = 0, \
.exec_buf = NULL, \
.arch = INIT_ARCH_THREAD, \
.request = { 0 } \
}
extern struct task_struct *alloc_task_struct(void);
static inline void release_thread(struct task_struct *task)
{
}
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
static inline void prepare_to_copy(struct task_struct *tsk)
{
}
extern unsigned long thread_saved_pc(struct task_struct *t);
static inline void mm_copy_segments(struct mm_struct *from_mm,
struct mm_struct *new_mm)
{
}
#define init_stack (init_thread_union.stack)
/*
* User space process size: 3GB (default).
*/
extern unsigned long task_size;
#define TASK_SIZE (task_size)
#undef STACK_TOP
#undef STACK_TOP_MAX
extern unsigned long stacksizelim;
#define STACK_ROOM (stacksizelim)
#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE)
#define STACK_TOP_MAX STACK_TOP
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (0x40000000)
extern void start_thread(struct pt_regs *regs, unsigned long entry,
unsigned long stack);
struct cpuinfo_um {
unsigned long loops_per_jiffy;
int ipi_pipe[2];
};
extern struct cpuinfo_um boot_cpu_data;
#define my_cpu_data cpu_data[smp_processor_id()]
#ifdef CONFIG_SMP
extern struct cpuinfo_um cpu_data[];
#define current_cpu_data cpu_data[smp_processor_id()]
#else
#define cpu_data (&boot_cpu_data)
#define current_cpu_data boot_cpu_data
#endif
#define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf)
extern unsigned long get_wchan(struct task_struct *p);
#endif