[PATCH] smp_processor_id() cleanup

This patch implements a number of smp_processor_id() cleanup ideas that
Arjan van de Ven and I came up with.

The previous __smp_processor_id/_smp_processor_id/smp_processor_id API
spaghetti was hard to follow both on the implementational and on the
usage side.

Some of the complexity arose from picking wrong names, some of the
complexity comes from the fact that not all architectures defined
__smp_processor_id.

In the new code, there are two externally visible symbols:

 - smp_processor_id(): debug variant.

 - raw_smp_processor_id(): nondebug variant. Replaces all existing
   uses of _smp_processor_id() and __smp_processor_id(). Defined
   by every SMP architecture in include/asm-*/smp.h.

There is one new internal symbol, dependent on DEBUG_PREEMPT:

 - debug_smp_processor_id(): internal debug variant, mapped to
                             smp_processor_id().

Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new
lib/smp_processor_id.c file.  All related comments got updated and/or
clarified.

I have build/boot tested the following 8 .config combinations on x86:

 {SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT}

I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT.  (Other
architectures are untested, but should work just fine.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

7 files changed, 8 insertions, 8 deletions

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 00c63419c06..83c579e82a8 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -306,7 +306,7 @@ void die(const char * str, struct pt_regs * regs, long err)
 	};
 	static int die_counter;
 
-	if (die.lock_owner != _smp_processor_id()) {
+	if (die.lock_owner != raw_smp_processor_id()) {
 		console_verbose();
 		spin_lock_irq(&die.lock);
 		die.lock_owner = smp_processor_id();
diff --git a/arch/i386/lib/delay.c b/arch/i386/lib/delay.c
index 080639f262b..eb0cdfe9280 100644
--- a/arch/i386/lib/delay.c
+++ b/arch/i386/lib/delay.c
@@ -34,7 +34,7 @@ inline void __const_udelay(unsigned long xloops)
 	xloops *= 4;
 	__asm__("mull %0"
 		:"=d" (xloops), "=&a" (d0)
-		:"1" (xloops),"0" (cpu_data[_smp_processor_id()].loops_per_jiffy * (HZ/4)));
+		:"1" (xloops),"0" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4)));
         __delay(++xloops);
 }
 
diff --git a/arch/ppc/lib/locks.c b/arch/ppc/lib/locks.c
index 694163d696d..c450dc4b766 100644
--- a/arch/ppc/lib/locks.c
+++ b/arch/ppc/lib/locks.c
@@ -130,7 +130,7 @@ void _raw_read_lock(rwlock_t *rw)
 		while (!read_can_lock(rw)) {
 			if (--stuck == 0) {
 				printk("_read_lock(%p) CPU#%d lock %d\n",
-				       rw, _smp_processor_id(), rw->lock);
+				       rw, raw_smp_processor_id(), rw->lock);
 				stuck = INIT_STUCK;
 			}
 		}
@@ -158,7 +158,7 @@ void _raw_write_lock(rwlock_t *rw)
 		while (!write_can_lock(rw)) {
 			if (--stuck == 0) {
 				printk("write_lock(%p) CPU#%d lock %d)\n",
-				       rw, _smp_processor_id(), rw->lock);
+				       rw, raw_smp_processor_id(), rw->lock);
 				stuck = INIT_STUCK;
 			}
 		}
diff --git a/arch/ppc64/kernel/idle.c b/arch/ppc64/kernel/idle.c
index f24ce2b8720..ff8a7db142d 100644
--- a/arch/ppc64/kernel/idle.c
+++ b/arch/ppc64/kernel/idle.c
@@ -292,7 +292,7 @@ static int native_idle(void)
 		if (need_resched())
 			schedule();
 
-		if (cpu_is_offline(_smp_processor_id()) &&
+		if (cpu_is_offline(raw_smp_processor_id()) &&
 		    system_state == SYSTEM_RUNNING)
 			cpu_die();
 	}
diff --git a/arch/sh/lib/delay.c b/arch/sh/lib/delay.c
index 50b36037d86..351714694d6 100644
--- a/arch/sh/lib/delay.c
+++ b/arch/sh/lib/delay.c
@@ -24,7 +24,7 @@ inline void __const_udelay(unsigned long xloops)
 	__asm__("dmulu.l	%0, %2\n\t"
 		"sts	mach, %0"
 		: "=r" (xloops)
-		: "0" (xloops), "r" (cpu_data[_smp_processor_id()].loops_per_jiffy)
+		: "0" (xloops), "r" (cpu_data[raw_smp_processor_id()].loops_per_jiffy)
 		: "macl", "mach");
 	__delay(xloops * HZ);
 }
diff --git a/arch/sparc64/lib/delay.c b/arch/sparc64/lib/delay.c
index f6b4c784d53..e8808727617 100644
--- a/arch/sparc64/lib/delay.c
+++ b/arch/sparc64/lib/delay.c
@@ -31,7 +31,7 @@ void __const_udelay(unsigned long n)
 {
 	n *= 4;
 
-	n *= (cpu_data(_smp_processor_id()).udelay_val * (HZ/4));
+	n *= (cpu_data(raw_smp_processor_id()).udelay_val * (HZ/4));
 	n >>= 32;
 
 	__delay(n + 1);
diff --git a/arch/x86_64/lib/delay.c b/arch/x86_64/lib/delay.c
index 6e2d66472eb..aed61a668a1 100644
--- a/arch/x86_64/lib/delay.c
+++ b/arch/x86_64/lib/delay.c
@@ -34,7 +34,7 @@ void __delay(unsigned long loops)
 
 inline void __const_udelay(unsigned long xloops)
 {
-	__delay(((xloops * cpu_data[_smp_processor_id()].loops_per_jiffy) >> 32) * HZ);
+	__delay(((xloops * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) * HZ);
 }
 
 void __udelay(unsigned long usecs)