From: David S. Miller <davem@davemloft.net>
Date: Mon, 4 Aug 2008 06:56:28 +0000 (-0700)
Subject: sparc64: Call xcall_deliver() directly in some cases.
X-Git-Tag: v2.6.27-rc2~41^2~8
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=199266305311d060b6e057fa5c7de01f218bb911;p=linux-2.6-omap-h63xx.git

sparc64: Call xcall_deliver() directly in some cases.

For these cases the callers make sure:

1) The cpus indicated are online.

2) The current cpu is not in the list of indicated cpus.

Therefore we can pass a pointer to the mask directly.

One of the motivations in this transformation is to make use of
"&cpumask_of_cpu(cpu)" which evaluates to a pointer to constant
data in the kernel and thus takes up no stack space.

Hopefully someone in the future will change the interface of
arch_send_call_function_ipi() such that it passes a const cpumask_t
pointer so that this will optimize ever further.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index 868625e3b66..47b0738ea4b 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -792,16 +792,15 @@ extern unsigned long xcall_call_function;
 
 void arch_send_call_function_ipi(cpumask_t mask)
 {
-	smp_cross_call_masked(&xcall_call_function, 0, 0, 0, mask);
+	xcall_deliver((u64) &xcall_call_function, 0, 0, &mask);
 }
 
 extern unsigned long xcall_call_function_single;
 
 void arch_send_call_function_single_ipi(int cpu)
 {
-	cpumask_t mask = cpumask_of_cpu(cpu);
-
-	smp_cross_call_masked(&xcall_call_function_single, 0, 0, 0, mask);
+	xcall_deliver((u64) &xcall_call_function_single, 0, 0,
+		      &cpumask_of_cpu(cpu));
 }
 
 /* Send cross call to all processors except self. */
@@ -959,24 +958,6 @@ void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
 	put_cpu();
 }
 
-static void __smp_receive_signal_mask(cpumask_t mask)
-{
-	smp_cross_call_masked(&xcall_receive_signal, 0, 0, 0, mask);
-}
-
-void smp_receive_signal(int cpu)
-{
-	cpumask_t mask = cpumask_of_cpu(cpu);
-
-	if (cpu_online(cpu))
-		__smp_receive_signal_mask(mask);
-}
-
-void smp_receive_signal_client(int irq, struct pt_regs *regs)
-{
-	clear_softint(1 << irq);
-}
-
 void smp_new_mmu_context_version_client(int irq, struct pt_regs *regs)
 {
 	struct mm_struct *mm;
@@ -1374,7 +1355,13 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 void smp_send_reschedule(int cpu)
 {
-	smp_receive_signal(cpu);
+	xcall_deliver((u64) &xcall_receive_signal, 0, 0,
+		      &cpumask_of_cpu(cpu));
+}
+
+void smp_receive_signal_client(int irq, struct pt_regs *regs)
+{
+	clear_softint(1 << irq);
 }
 
 /* This is a nop because we capture all other cpus