microblaze: switch to generic kernel_thread()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 4cba7439f9de897a9de9abb91ab2c3596e4fa8a1..3b8df669eecd3c4826387554498e33b126216855 100644 (file)
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -26,6 +26,7 @@ config MICROBLAZE
        select GENERIC_ATOMIC64
        select GENERIC_CLOCKEVENTS
        select MODULES_USE_ELF_RELA
+       select GENERIC_KERNEL_THREAD
 
 config SWAP
        def_bool n

diff --git a/arch/microblaze/include/asm/processor.h b/arch/microblaze/include/asm/processor.h
index af2bb9652392e9ecb80980c51a0ebf2b3390e526..0759153e81179b7a68909b9154d52afa1c2732c7 100644 (file)
--- a/arch/microblaze/include/asm/processor.h
+++ b/arch/microblaze/include/asm/processor.h
@@ -31,6 +31,7 @@ extern const struct seq_operations cpuinfo_op;
 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp);
 
 extern void ret_from_fork(void);
+extern void ret_from_kernel_thread(void);
 
 # endif /* __ASSEMBLY__ */
 
@@ -78,11 +79,6 @@ extern unsigned long thread_saved_pc(struct task_struct *t);
 
 extern unsigned long get_wchan(struct task_struct *p);
 
-/*
- * create a kernel thread without removing it from tasklists
- */
-extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 # define KSTK_EIP(tsk) (0)
 # define KSTK_ESP(tsk) (0)
 
@@ -131,8 +127,6 @@ extern inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 /* Free current thread data structures etc.  */
 static inline void exit_thread(void)
 {

diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index 75c3ea1f48a123e07aeaf97481ed81ad204670ab..c47e92cd7e78b27049f4ef09e80d9e1815b65542 100644 (file)
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -474,6 +474,14 @@ ENTRY(ret_from_fork)
        brid    ret_to_user
        nop
 
+ENTRY(ret_from_kernel_thread)
+       brlid   r15, schedule_tail
+       addk    r5, r0, r3
+       brald   r15, r20
+       addk    r5, r0, r19
+       brid    sys_exit        /* won't be returning... */
+       addk    r5, r0, r0
+
 work_pending:
        enable_irq
 

diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 1cf702ab7463b1d7fce434d19aad16a23ceca4b6..be76d1338be06b1b0d64df72d003f6cef1c2908a 100644 (file)
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -484,6 +484,15 @@ C_ENTRY(ret_from_fork):
        brid    ret_from_trap;  /* Do normal trap return */
        add     r3, r0, r0;     /* Child's fork call should return 0. */
 
+C_ENTRY(ret_from_kernel_thread):
+       bralid  r15, schedule_tail; /* ...which is schedule_tail's arg */
+       add     r5, r3, r0;     /* switch_thread returns the prev task */
+                               /* ( in the delay slot ) */
+       brald   r15, r20        /* fn was left in r20 */
+       addk    r5, r0, r19     /* ... and argument - in r19 */
+       brid    sys_exit        /* won't be returning... */
+       addk    r5, r0, r0
+
 C_ENTRY(sys_vfork):
        brid    microblaze_vfork        /* Do real work (tail-call) */
        addik   r5, r1, 0

diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index 1944e00f07e1d4185cbf8bbdf894591192ef6abd..cbf8bb92f15960ceba01830a4c3a8401bfb58ee8 100644 (file)
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -119,46 +119,38 @@ void flush_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 = task_pt_regs(p);
        struct thread_info *ti = task_thread_info(p);
 
+       if (unlikely(p->flags & PF_KTHREAD)) {
+               /* if we're creating a new kernel thread then just zeroing all
+                * the registers. That's OK for a brand new thread.*/
+               memset(childregs, 0, sizeof(struct pt_regs));
+               memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
+               ti->cpu_context.r1  = (unsigned long)childregs;
+               ti->cpu_context.r20 = (unsigned long)usp; /* fn */
+               ti->cpu_context.r19 = (unsigned long)arg;
+               childregs->pt_mode = 1;
+               local_save_flags(childregs->msr);
+#ifdef CONFIG_MMU
+               ti->cpu_context.msr = childregs->msr & ~MSR_IE;
+#endif
+               ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
+               return 0;
+       }
        *childregs = *regs;
-       if (user_mode(regs))
-               childregs->r1 = usp;
-       else
-               childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
+       childregs->r1 = usp;
 
-#ifndef CONFIG_MMU
        memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
        ti->cpu_context.r1 = (unsigned long)childregs;
+#ifndef CONFIG_MMU
        ti->cpu_context.msr = (unsigned long)childregs->msr;
 #else
+       childregs->msr |= MSR_UMS;
 
-       /* if creating a kernel thread then update the current reg (we don't
-        * want to use the parent's value when restoring by POP_STATE) */
-       if (kernel_mode(regs))
-               /* save new current on stack to use POP_STATE */
-               childregs->CURRENT_TASK = (unsigned long)p;
-       /* if returning to user then use the parent's value of this register */
-
-       /* if we're creating a new kernel thread then just zeroing all
-        * the registers. That's OK for a brand new thread.*/
-       /* Pls. note that some of them will be restored in POP_STATE */
-       if (kernel_mode(regs))
-               memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
-       /* if this thread is created for fork/vfork/clone, then we want to
-        * restore all the parent's context */
-       /* in addition to the registers which will be restored by POP_STATE */
-       else {
-               ti->cpu_context = *(struct cpu_context *)regs;
-               childregs->msr |= MSR_UMS;
-       }
-
-       /* FIXME STATE_SAVE_PT_OFFSET; */
-       ti->cpu_context.r1  = (unsigned long)childregs;
        /* we should consider the fact that childregs is a copy of the parent
         * regs which were saved immediately after entering the kernel state
         * before enabling VM. This MSR will be restored in switch_to and
@@ -209,29 +201,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 }
 #endif
 
-static void kernel_thread_helper(int (*fn)(void *), void *arg)
-{
-       fn(arg);
-       do_exit(-1);
-}
-
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-       struct pt_regs regs;
-
-       memset(&regs, 0, sizeof(regs));
-       /* store them in non-volatile registers */
-       regs.r5 = (unsigned long)fn;
-       regs.r6 = (unsigned long)arg;
-       local_save_flags(regs.msr);
-       regs.pc = (unsigned long)kernel_thread_helper;
-       regs.pt_mode = 1;
-
-       return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
-                       &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL_GPL(kernel_thread);
-
 unsigned long get_wchan(struct task_struct *p)
 {
 /* TBD (used by procfs) */