Re: [PATCH 18/22] Fix M68K irqflags

From: David Howells
Date: Wed Sep 01 2010 - 07:30:44 EST



> Here is a spin of the same patch, only with a single irqflags.h.
> It is closely modeled on the mm version, merging (and cleaning)
> the non-mmu bits as needed. There is a fair bit of common code
> in here.
>
> It does refactor arch_local_irq_save() but I am pretty sure that
> makes no impact (performance or code size). I have left
> arch_irq_enable as-is for all, it is not clear to me why it is
> the way it is for the mm case (Geert?)

Here's my take on your patch. By removing a couple of apparently unnecessary
refs to asm/system.h I can turn the #define of arch_local_irq_enable() into an
inline function.

Should I take it that Coldfire chips lack the AND/OR directly to SR
instructions?

David
---
arch/m68k/include/asm/irqflags.h | 76 ++++++++++++++++++++++++++++++++++++++
arch/m68k/include/asm/system_mm.h | 25 ------------
arch/m68k/include/asm/system_no.h | 49 ------------------------
include/linux/hardirq.h | 1
include/linux/list.h | 1
5 files changed, 78 insertions(+), 74 deletions(-)

diff --git a/arch/m68k/include/asm/irqflags.h b/arch/m68k/include/asm/irqflags.h
new file mode 100644
index 0000000..b186de8
--- /dev/null
+++ b/arch/m68k/include/asm/irqflags.h
@@ -0,0 +1,76 @@
+#ifndef _M68K_IRQFLAGS_MM_H
+#define _M68K_IRQFLAGS_MM_H
+
+#include <linux/types.h>
+#include <linux/hardirq.h>
+#include <linux/preempt.h>
+#include <asm/thread_info.h>
+#include <asm/entry.h>
+
+static inline unsigned long arch_local_save_flags(void)
+{
+ unsigned long flags;
+ asm volatile ("movew %%sr,%0": "=d" (flags) : : "memory");
+ return flags;
+}
+
+static inline void arch_local_irq_disable(void)
+{
+#ifdef CONFIG_COLDFIRE
+ asm volatile (
+ "move %/sr,%%d0 \n\t"
+ "ori.l #0x0700,%%d0 \n\t"
+ "move %%d0,%/sr \n"
+ : /* no outputs */
+ :
+ : "cc", "%d0", "memory");
+#else
+ asm volatile ("oriw #0x0700,%%sr" : : : "memory");
+#endif
+}
+
+static inline void arch_local_irq_enable(void)
+{
+#if defined(CONFIG_COLDFIRE)
+ asm volatile (
+ "move %/sr,%%d0 \n\t"
+ "andi.l #0xf8ff,%%d0 \n\t"
+ "move %%d0,%/sr \n"
+ : /* no outputs */
+ :
+ : "cc", "%d0", "memory");
+#else
+# if defined(CONFIG_MMU)
+ if (MACH_IS_Q40 || !hardirq_count())
+# endif
+ asm volatile (
+ "andiw %0,%%sr"
+ :
+ : "i" (ALLOWINT)
+ : "memory")
+#endif
+}
+
+static inline unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags = arch_local_save_flags();
+ arch_local_irq_disable();
+ return flags;
+}
+
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+ asm volatile ("movew %0,%%sr": : "d" (flags) : "memory");
+}
+
+static inline bool arch_irqs_disabled_flags(unsigned long flags)
+{
+ return (flags & ~ALLOWINT) != 0;
+}
+
+static inline bool arch_irqs_disabled(void)
+{
+ return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+#endif /* _M68K_IRQFLAGS_MM_H */
diff --git a/arch/m68k/include/asm/system_mm.h b/arch/m68k/include/asm/system_mm.h
index dbb6515..12053c4 100644
--- a/arch/m68k/include/asm/system_mm.h
+++ b/arch/m68k/include/asm/system_mm.h
@@ -3,6 +3,7 @@

#include <linux/linkage.h>
#include <linux/kernel.h>
+#include <linux/irqflags.h>
#include <asm/segment.h>
#include <asm/entry.h>

@@ -62,30 +63,6 @@ asmlinkage void resume(void);
#define smp_wmb() barrier()
#define smp_read_barrier_depends() ((void)0)

-/* interrupt control.. */
-#if 0
-#define local_irq_enable() asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory")
-#else
-#include <linux/hardirq.h>
-#define local_irq_enable() ({ \
- if (MACH_IS_Q40 || !hardirq_count()) \
- asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory"); \
-})
-#endif
-#define local_irq_disable() asm volatile ("oriw #0x0700,%%sr": : : "memory")
-#define local_save_flags(x) asm volatile ("movew %%sr,%0":"=d" (x) : : "memory")
-#define local_irq_restore(x) asm volatile ("movew %0,%%sr": :"d" (x) : "memory")
-
-static inline int irqs_disabled(void)
-{
- unsigned long flags;
- local_save_flags(flags);
- return flags & ~ALLOWINT;
-}
-
-/* For spinlocks etc */
-#define local_irq_save(x) ({ local_save_flags(x); local_irq_disable(); })
-
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

struct __xchg_dummy { unsigned long a[100]; };
diff --git a/arch/m68k/include/asm/system_no.h b/arch/m68k/include/asm/system_no.h
index 3c0718d..52ca8da 100644
--- a/arch/m68k/include/asm/system_no.h
+++ b/arch/m68k/include/asm/system_no.h
@@ -2,6 +2,7 @@
#define _M68KNOMMU_SYSTEM_H

#include <linux/linkage.h>
+#include <linux/irqflags.h>
#include <asm/segment.h>
#include <asm/entry.h>

@@ -46,54 +47,6 @@ asmlinkage void resume(void);
(last) = _last; \
}

-#ifdef CONFIG_COLDFIRE
-#define local_irq_enable() __asm__ __volatile__ ( \
- "move %/sr,%%d0\n\t" \
- "andi.l #0xf8ff,%%d0\n\t" \
- "move %%d0,%/sr\n" \
- : /* no outputs */ \
- : \
- : "cc", "%d0", "memory")
-#define local_irq_disable() __asm__ __volatile__ ( \
- "move %/sr,%%d0\n\t" \
- "ori.l #0x0700,%%d0\n\t" \
- "move %%d0,%/sr\n" \
- : /* no outputs */ \
- : \
- : "cc", "%d0", "memory")
-/* For spinlocks etc */
-#define local_irq_save(x) __asm__ __volatile__ ( \
- "movew %%sr,%0\n\t" \
- "movew #0x0700,%%d0\n\t" \
- "or.l %0,%%d0\n\t" \
- "movew %%d0,%/sr" \
- : "=d" (x) \
- : \
- : "cc", "%d0", "memory")
-#else
-
-/* portable version */ /* FIXME - see entry.h*/
-#define ALLOWINT 0xf8ff
-
-#define local_irq_enable() asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory")
-#define local_irq_disable() asm volatile ("oriw #0x0700,%%sr": : : "memory")
-#endif
-
-#define local_save_flags(x) asm volatile ("movew %%sr,%0":"=d" (x) : : "memory")
-#define local_irq_restore(x) asm volatile ("movew %0,%%sr": :"d" (x) : "memory")
-
-/* For spinlocks etc */
-#ifndef local_irq_save
-#define local_irq_save(x) do { local_save_flags(x); local_irq_disable(); } while (0)
-#endif
-
-#define irqs_disabled() \
-({ \
- unsigned long flags; \
- local_save_flags(flags); \
- ((flags & 0x0700) == 0x0700); \
-})
-
#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")

/*
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index d5b3876..7dfdc06 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -8,7 +8,6 @@
#include <linux/lockdep.h>
#include <linux/ftrace_irq.h>
#include <asm/hardirq.h>
-#include <asm/system.h>

/*
* We put the hardirq and softirq counter into the preemption
diff --git a/include/linux/list.h b/include/linux/list.h
index d167b5d..88a0006 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -5,7 +5,6 @@
#include <linux/stddef.h>
#include <linux/poison.h>
#include <linux/prefetch.h>
-#include <asm/system.h>

/*
* Simple doubly linked list implementation.
--
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