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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-09 16:27:45 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-14 19:30:25 -0400
commit8f54bcacbc39f883bde2210cf2754e5d198f55a4 (patch)
tree1ed53a3cf864bd6372021d4384b70070da23345c /arch/mips/kernel/process.c
parentddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)
mips: switch to generic kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/mips/kernel/process.c')
-rw-r--r--arch/mips/kernel/process.c62
1 files changed, 22 insertions, 40 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index e9a5fd7277f4..d13720ac656f 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -84,6 +84,7 @@ void __noreturn cpu_idle(void)
}
asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
{
@@ -113,7 +114,7 @@ void flush_thread(void)
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused, struct task_struct *p, struct pt_regs *regs)
+ unsigned long arg, struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
@@ -136,19 +137,30 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
childregs = (struct pt_regs *) childksp - 1;
/* Put the stack after the struct pt_regs. */
childksp = (unsigned long) childregs;
+ p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ unsigned long status = p->thread.cp0_status;
+ memset(childregs, 0, sizeof(struct pt_regs));
+ ti->addr_limit = KERNEL_DS;
+ p->thread.reg16 = usp; /* fn */
+ p->thread.reg17 = arg;
+ p->thread.reg29 = childksp;
+ p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+ status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
+ ((status & (ST0_KUC | ST0_IEC)) << 2);
+#else
+ status |= ST0_EXL;
+#endif
+ childregs->cp0_status = status;
+ return 0;
+ }
*childregs = *regs;
childregs->regs[7] = 0; /* Clear error flag */
-
childregs->regs[2] = 0; /* Child gets zero as return value */
+ childregs->regs[29] = usp;
+ ti->addr_limit = USER_DS;
- if (childregs->cp0_status & ST0_CU0) {
- childregs->regs[28] = (unsigned long) ti;
- childregs->regs[29] = childksp;
- ti->addr_limit = KERNEL_DS;
- } else {
- childregs->regs[29] = usp;
- ti->addr_limit = USER_DS;
- }
p->thread.reg29 = (unsigned long) childregs;
p->thread.reg31 = (unsigned long) ret_from_fork;
@@ -156,7 +168,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* New tasks lose permission to use the fpu. This accelerates context
* switching for most programs since they don't use the fpu.
*/
- p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
#ifdef CONFIG_MIPS_MT_SMTC
@@ -222,35 +233,6 @@ int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr)
}
/*
- * Create a kernel thread
- */
-static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *))
-{
- do_exit(fn(arg));
-}
-
-long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
- struct pt_regs regs;
-
- memset(&regs, 0, sizeof(regs));
-
- regs.regs[4] = (unsigned long) arg;
- regs.regs[5] = (unsigned long) fn;
- regs.cp0_epc = (unsigned long) kernel_thread_helper;
- regs.cp0_status = read_c0_status();
-#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
- regs.cp0_status = (regs.cp0_status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
- ((regs.cp0_status & (ST0_KUC | ST0_IEC)) << 2);
-#else
- regs.cp0_status |= ST0_EXL;
-#endif
-
- /* Ok, create the new process.. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
-}
-
-/*
*
*/
struct mips_frame_info {