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cris: switch to generic kernel_thread() 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-03 14:46:55 -04:00
parent ddffeb8c4d
commit 69b58a6721
7 changed files with 69 additions and 115 deletions
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1
arch/cris/Kconfig
View File

@ -49,6 +49,7 @@ config CRIS
select GENERIC_SMP_IDLE_THREAD if ETRAX_ARCH_V32
select GENERIC_CMOS_UPDATE
select MODULES_USE_ELF_RELA
select GENERIC_KERNEL_THREAD
config HZ
int

10
arch/cris/arch-v10/kernel/entry.S
View File

@ -35,6 +35,7 @@
.globl system_call
.globl ret_from_intr
.globl ret_from_fork
.globl ret_from_kernel_thread
.globl resume
.globl multiple_interrupt
.globl hwbreakpoint
@ -81,7 +82,14 @@ ret_from_fork:
jsr schedule_tail
ba ret_from_sys_call
nop
ret_from_kernel_thread:
jsr schedule_tail
move.d $r2, $r10 ; argument is here
jsr $r1 ; call the payload
moveq 0, $r10
jsr sys_exit ; never returns
ret_from_intr:
;; check for resched if preemptive kernel or if we're going back to user-mode
;; this test matches the user_regs(regs) macro

83
arch/cris/arch-v10/kernel/process.c
View File

@ -17,6 +17,7 @@
#include <arch/svinto.h>
#include <linux/init.h>
#include <arch/system.h>
#include <asm/ptrace.h>
#ifdef CONFIG_ETRAX_GPIO
void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
@ -81,31 +82,6 @@ unsigned long thread_saved_pc(struct task_struct *t)
return task_pt_regs(t)->irp;
}
static void kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
{
fn(arg);
do_exit(-1); /* Should never be called, return bad exit value */
}
/*
* Create a kernel thread
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
/* Don't use r10 since that is set to 0 in copy_thread */
regs.r11 = (unsigned long)fn;
regs.r12 = (unsigned long)arg;
regs.irp = (unsigned long)kernel_thread_helper;
regs.dccr = 1 << I_DCCR_BITNR;
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
/* setup the child's kernel stack with a pt_regs and switch_stack on it.
* it will be un-nested during _resume and _ret_from_sys_call when the
* new thread is scheduled.
@ -115,29 +91,35 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
*
*/
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs * childregs;
struct switch_stack *swstack;
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *swstack = ((struct switch_stack *)childregs) - 1;
/* put the pt_regs structure at the end of the new kernel stack page and fix it up
* remember that the task_struct doubles as the kernel stack for the task
*/
childregs = task_pt_regs(p);
if (unlikely(p->flags & PF_KTHREAD)) {
memset(swstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
swstack->r1 = usp;
swstack->r2 = arg;
childregs->dccr = 1 << I_DCCR_BITNR;
swstack->return_ip = (unsigned long) ret_from_kernel_thread;
p->thread.ksp = (unsigned long) swstack;
p->thread.usp = 0;
return 0;
}
*childregs = *regs; /* struct copy of pt_regs */
p->set_child_tid = p->clear_child_tid = NULL;
childregs->r10 = 0; /* child returns 0 after a fork/clone */
/* put the switch stack right below the pt_regs */
swstack = ((struct switch_stack *)childregs) - 1;
/* put the switch stack right below the pt_regs */
swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */
@ -147,7 +129,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
/* fix the user-mode stackpointer */
p->thread.usp = usp;
p->thread.usp = usp;
/* and the kernel-mode one */
@ -161,45 +143,28 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
return 0;
}
/*
* Be aware of the "magic" 7th argument in the four system-calls below.
* They need the latest stackframe, which is put as the 7th argument by
* entry.S. The previous arguments are dummies or actually used, but need
* to be defined to reach the 7th argument.
*
* N.B.: Another method to get the stackframe is to use current_regs(). But
* it returns the latest stack-frame stacked when going from _user mode_ and
* some of these (at least sys_clone) are called from kernel-mode sometimes
* (for example during kernel_thread, above) and thus cannot use it. Thus,
* to be sure not to get any surprises, we use the method for the other calls
* as well.
*/
asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
asmlinkage int sys_fork(void)
{
return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
return do_fork(SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/* if newusp is 0, we just grab the old usp */
/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
asmlinkage int sys_clone(unsigned long newusp, unsigned long flags,
int* parent_tid, int* child_tid, long mof, long srp,
struct pt_regs *regs)
int* parent_tid, int* child_tid)
{
if (!newusp)
newusp = rdusp();
return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
return do_fork(flags, newusp, current_pt_regs(), 0, parent_tid, child_tid);
}
/* vfork is a system call in i386 because of register-pressure - maybe
* we can remove it and handle it in libc but we put it here until then.
*/
asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
asmlinkage int sys_vfork(void)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/*

13
arch/cris/arch-v32/kernel/entry.S
View File

@ -31,6 +31,7 @@
.globl system_call
.globl ret_from_intr
.globl ret_from_fork
.globl ret_from_kernel_thread
.globl resume
.globl multiple_interrupt
.globl nmi_interrupt
@ -84,6 +85,18 @@ ret_from_fork:
nop
.size ret_from_fork, . - ret_from_fork
.type ret_from_kernel_thread,@function
ret_from_kernel_thread:
jsr schedule_tail
nop
move.d $r2, $r10
jsr $r1
nop
moveq 0, $r10
jsr sys_exit
nop
.size ret_from_kernel_thread, . - ret_from_kernel_thread
.type ret_from_intr,@function
ret_from_intr:
;; Check for resched if preemptive kernel, or if we're going back to

74
arch/cris/arch-v32/kernel/process.c
View File

@ -16,6 +16,7 @@
#include <hwregs/reg_map.h>
#include <hwregs/timer_defs.h>
#include <hwregs/intr_vect_defs.h>
#include <asm/ptrace.h>
extern void stop_watchdog(void);
@ -94,31 +95,6 @@ unsigned long thread_saved_pc(struct task_struct *t)
return task_pt_regs(t)->erp;
}
static void
kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
{
fn(arg);
do_exit(-1); /* Should never be called, return bad exit value. */
}
/* Create a kernel thread. */
int
kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
/* Don't use r10 since that is set to 0 in copy_thread. */
regs.r11 = (unsigned long) fn;
regs.r12 = (unsigned long) arg;
regs.erp = (unsigned long) kernel_thread_helper;
regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
/* Create the new process. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
/*
* Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
* It will be unnested during _resume and _ret_from_sys_call when the new thread
@ -129,23 +105,33 @@ kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
*/
extern asmlinkage void ret_from_fork(void);
extern asmlinkage void ret_from_kernel_thread(void);
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs;
struct switch_stack *swstack;
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *swstack = ((struct switch_stack *) childregs) - 1;
/*
* Put the pt_regs structure at the end of the new kernel stack page and
* fix it up. Note: the task_struct doubles as the kernel stack for the
* task.
*/
childregs = task_pt_regs(p);
if (unlikely(p->flags & PF_KTHREAD)) {
memset(swstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
swstack->r1 = usp;
swstack->r2 = arg;
childregs->ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
swstack->return_ip = (unsigned long) ret_from_kernel_thread;
p->thread.ksp = (unsigned long) swstack;
p->thread.usp = 0;
return 0;
}
*childregs = *regs; /* Struct copy of pt_regs. */
p->set_child_tid = p->clear_child_tid = NULL;
childregs->r10 = 0; /* Child returns 0 after a fork/clone. */
/* Set a new TLS ?
@ -156,7 +142,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
}
/* Put the switch stack right below the pt_regs. */
swstack = ((struct switch_stack *) childregs) - 1;
/* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
swstack->r9 = 0;
@ -174,35 +159,21 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
return 0;
}
/*
* Be aware of the "magic" 7th argument in the four system-calls below.
* They need the latest stackframe, which is put as the 7th argument by
* entry.S. The previous arguments are dummies or actually used, but need
* to be defined to reach the 7th argument.
*
* N.B.: Another method to get the stackframe is to use current_regs(). But
* it returns the latest stack-frame stacked when going from _user mode_ and
* some of these (at least sys_clone) are called from kernel-mode sometimes
* (for example during kernel_thread, above) and thus cannot use it. Thus,
* to be sure not to get any surprises, we use the method for the other calls
* as well.
*/
asmlinkage int
sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
sys_fork(void)
{
return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
return do_fork(SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
asmlinkage int
sys_clone(unsigned long newusp, unsigned long flags, int *parent_tid, int *child_tid,
unsigned long tls, long srp, struct pt_regs *regs)
unsigned long tls)
{
if (!newusp)
newusp = rdusp();
return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
return do_fork(flags, newusp, current_pt_regs(), 0, parent_tid, child_tid);
}
/*
@ -210,10 +181,9 @@ sys_clone(unsigned long newusp, unsigned long flags, int *parent_tid, int *child
* we can remove it and handle it in libc but we put it here until then.
*/
asmlinkage int
sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
sys_vfork(void)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/* sys_execve() executes a new program. */

2
arch/cris/include/asm/processor.h
View File

@ -49,8 +49,6 @@ struct task_struct;
#define task_pt_regs(task) user_regs(task_thread_info(task))
#define current_regs() task_pt_regs(current)
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
unsigned long get_wchan(struct task_struct *p);
#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)

1
arch/cris/kernel/crisksyms.c
View File

@ -30,7 +30,6 @@ extern void __negdi2(void);
extern void iounmap(volatile void * __iomem);
/* Platform dependent support */
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(get_cmos_time);
EXPORT_SYMBOL(loops_per_usec);