alpha: switch to generic kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 9944ded..7da9124 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -20,6 +20,7 @@
select GENERIC_CMOS_UPDATE
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
+ select GENERIC_KERNEL_THREAD
help
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h
index e37b887..6cb7fe8 100644
--- a/arch/alpha/include/asm/processor.h
+++ b/arch/alpha/include/asm/processor.h
@@ -49,9 +49,6 @@
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
-/* Create a kernel thread without removing it from tasklists. */
-extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
index 15fa821..89566b3 100644
--- a/arch/alpha/kernel/alpha_ksyms.c
+++ b/arch/alpha/kernel/alpha_ksyms.c
@@ -50,9 +50,6 @@
EXPORT_SYMBOL(alpha_write_fp_reg);
EXPORT_SYMBOL(alpha_write_fp_reg_s);
-/* entry.S */
-EXPORT_SYMBOL(kernel_thread);
-
/* Networking helper routines. */
EXPORT_SYMBOL(csum_tcpudp_magic);
EXPORT_SYMBOL(ip_compute_csum);
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 61ff145..421dccf 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -609,59 +609,22 @@
.end ret_from_fork
/*
- * kernel_thread(fn, arg, clone_flags)
+ * ... and new kernel threads - here
*/
.align 4
- .globl kernel_thread
- .ent kernel_thread
-kernel_thread:
- /* We can be called from a module. */
- ldgp $gp, 0($27)
- .prologue 1
- subq $sp, SP_OFF+6*8, $sp
- br $1, 2f /* load start address */
-
- /* We've now "returned" from a fake system call. */
- unop
- blt $0, 1f /* error? */
- ldi $1, 0x3fff
- beq $20, 1f /* parent or child? */
-
- bic $sp, $1, $8 /* in child. */
- jsr $26, ($27)
+ .globl ret_from_kernel_thread
+ .ent ret_from_kernel_thread
+ret_from_kernel_thread:
+ mov $17, $16
+ jsr $26, schedule_tail
+ mov $9, $27
+ mov $10, $16
+ jsr $26, ($9)
ldgp $gp, 0($26)
mov $0, $16
mov $31, $26
jmp $31, sys_exit
-
-1: ret /* in parent. */
-
- .align 4
-2: /* Fake a system call stack frame, as we can't do system calls
- from kernel space. Note that we store FN and ARG as they
- need to be set up in the child for the call. Also store $8
- and $26 for use in the parent. */
- stq $31, SP_OFF($sp) /* ps */
- stq $1, SP_OFF+8($sp) /* pc */
- stq $gp, SP_OFF+16($sp) /* gp */
- stq $16, 136($sp) /* $27; FN for child */
- stq $17, SP_OFF+24($sp) /* $16; ARG for child */
- stq $8, 64($sp) /* $8 */
- stq $26, 128($sp) /* $26 */
- /* Avoid the HAE being gratuitously wrong, to avoid restoring it. */
- ldq $2, alpha_mv+HAE_CACHE
- stq $2, 152($sp) /* HAE */
-
- /* Shuffle FLAGS to the front; add CLONE_VM. */
- ldi $1, CLONE_VM|CLONE_UNTRACED
- or $18, $1, $16
- bsr $26, sys_clone
-
- /* We don't actually care for a3 success widgetry in the kernel.
- Not for positive errno values. */
- stq $0, 0($sp) /* $0 */
- br ret_to_kernel
-.end kernel_thread
+.end ret_from_kernel_thread
/*
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 14547390..6b33ecd 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -259,33 +259,35 @@
/*
* 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(unsigned long clone_flags, unsigned long usp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct * p, struct pt_regs * regs)
{
extern void ret_from_fork(void);
+ extern void ret_from_kernel_thread(void);
struct thread_info *childti = task_thread_info(p);
- struct pt_regs * childregs;
- struct switch_stack * childstack, *stack;
- unsigned long stack_offset, settls;
+ struct pt_regs *childregs = task_pt_regs(p);
+ struct switch_stack *childstack, *stack;
+ unsigned long 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 + task_stack_page(p));
-
+ childstack = ((struct switch_stack *) childregs) - 1;
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childstack, 0,
+ sizeof(struct switch_stack) + sizeof(struct pt_regs));
+ childstack->r26 = (unsigned long) ret_from_kernel_thread;
+ childstack->r9 = usp; /* function */
+ childstack->r10 = arg;
+ childregs->hae = alpha_mv.hae_cache,
+ childti->pcb.usp = 0;
+ childti->pcb.ksp = (unsigned long) childstack;
+ childti->pcb.flags = 1; /* set FEN, clear everything else */
+ return 0;
+ }
*childregs = *regs;
settls = regs->r20;
childregs->r0 = 0;
@@ -293,7 +295,6 @@
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;
