Re: [PATCH 18/22] Fix M68K irqflags

[David Howells <dhowells@redhat.com>]

> 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.