Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...

[safe/jmp/linux-2.6] / arch / microblaze / kernel / process.c

diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index 436f26c..09bed44 100644 (file)
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -15,10 +15,12 @@
 #include <linux/bitops.h>
 #include <asm/system.h>
 #include <asm/pgalloc.h>
+#include <asm/uaccess.h> /* for USER_DS macros */
+#include <asm/cacheflush.h>
 
 void show_regs(struct pt_regs *regs)
 {
-       printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->kernel_mode);
+       printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode);
        printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
                                regs->r1, regs->r2, regs->r3, regs->r4);
        printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
@@ -37,8 +39,6 @@ void show_regs(struct pt_regs *regs)
                                regs->r29, regs->r30, regs->r31, regs->pc);
        printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
                                regs->msr, regs->ear, regs->esr, regs->fsr);
-       while (1)
-               ;
 }
 
 void (*pm_idle)(void);
@@ -75,7 +75,10 @@ __setup("hlt", hlt_setup);
 
 void default_idle(void)
 {
-       if (!hlt_counter) {
+       if (likely(hlt_counter)) {
+               while (!need_resched())
+                       cpu_relax();
+       } else {
                clear_thread_flag(TIF_POLLING_NRFLAG);
                smp_mb__after_clear_bit();
                local_irq_disable();
@@ -83,9 +86,7 @@ void default_idle(void)
                        cpu_sleep();
                local_irq_enable();
                set_thread_flag(TIF_POLLING_NRFLAG);
-       } else
-               while (!need_resched())
-                       cpu_relax();
+       }
 }
 
 void cpu_idle(void)
@@ -128,9 +129,54 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
        else
                childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
 
+#ifndef CONFIG_MMU
        memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
        ti->cpu_context.r1 = (unsigned long)childregs;
        ti->cpu_context.msr = (unsigned long)childregs->msr;
+#else
+
+       /* 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 - STATE_SAVE_ARG_SPACE;
+       /* 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
+        * RETURN() and we want to have the right machine state there
+        * specifically this state must have INTs disabled before and enabled
+        * after performing rtbd
+        * compose the right MSR for RETURN(). It will work for switch_to also
+        * excepting for VM and UMS
+        * don't touch UMS , CARRY and cache bits
+        * right now MSR is a copy of parent one */
+       childregs->msr |= MSR_BIP;
+       childregs->msr &= ~MSR_EIP;
+       childregs->msr |= MSR_IE;
+       childregs->msr &= ~MSR_VM;
+       childregs->msr |= MSR_VMS;
+       childregs->msr |= MSR_EE; /* exceptions will be enabled*/
+
+       ti->cpu_context.msr = (childregs->msr|MSR_VM);
+       ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
+#endif
        ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
 
        if (clone_flags & CLONE_SETTLS)
@@ -139,6 +185,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
        return 0;
 }
 
+#ifndef CONFIG_MMU
 /*
  * Return saved PC of a blocked thread.
  */
@@ -153,6 +200,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
        else
                return ctx->r14;
 }
+#endif
 
 static void kernel_thread_helper(int (*fn)(void *), void *arg)
 {
@@ -163,7 +211,6 @@ static void kernel_thread_helper(int (*fn)(void *), void *arg)
 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 {
        struct pt_regs regs;
-       int ret;
 
        memset(&regs, 0, sizeof(regs));
        /* store them in non-volatile registers */
@@ -171,16 +218,38 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
        regs.r6 = (unsigned long)arg;
        local_save_flags(regs.msr);
        regs.pc = (unsigned long)kernel_thread_helper;
-       regs.kernel_mode = 1;
+       regs.pt_mode = 1;
 
-       ret = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
+       return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
                        &regs, 0, NULL, NULL);
-
-       return ret;
 }
+EXPORT_SYMBOL_GPL(kernel_thread);
 
 unsigned long get_wchan(struct task_struct *p)
 {
 /* TBD (used by procfs) */
        return 0;
 }
+
+/* Set up a thread for executing a new program */
+void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
+{
+       set_fs(USER_DS);
+       regs->pc = pc;
+       regs->r1 = usp;
+       regs->pt_mode = 0;
+#ifdef CONFIG_MMU
+       regs->msr |= MSR_UMS;
+#endif
+}
+
+#ifdef CONFIG_MMU
+#include <linux/elfcore.h>
+/*
+ * Set up a thread for executing a new program
+ */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
+{
+       return 0; /* MicroBlaze has no separate FPU registers */
+}
+#endif /* CONFIG_MMU */