From 7abea9214585823f7f19d91872d7c6f8874bef9a Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@sunset.davemloft.net>
Date: Sat, 25 Feb 2006 13:39:56 -0800
Subject: [PATCH] [SPARC64]: Make cpu_present_map available earlier.

The change to kernel/sched.c's init code to use for_each_cpu()
requires that the cpu_possible_map be setup much earlier.

Set it up via setup_arch(), constrained to NR_CPUS, and later
constrain it to max_cpus in smp_prepare_cpus().

This fixes SMP booting on sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc64/kernel/setup.c |  2 ++
 arch/sparc64/kernel/smp.c   | 28 +++++++++++++++++++---------
 include/asm-sparc64/smp.h   |  6 ++++++
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/arch/sparc64/kernel/setup.c b/arch/sparc64/kernel/setup.c
index 054461e6946..158bd31e15b 100644
--- a/arch/sparc64/kernel/setup.c
+++ b/arch/sparc64/kernel/setup.c
@@ -542,6 +542,8 @@ void __init setup_arch(char **cmdline_p)
 	}
 #endif
 
+	smp_setup_cpu_possible_map();
+
 	paging_init();
 }
 
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index 1fb6323e65a..1f7ad8a6905 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -1079,18 +1079,12 @@ int setup_profiling_timer(unsigned int multiplier)
 	return 0;
 }
 
+/* Constrain the number of cpus to max_cpus.  */
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
-	int instance, mid;
-
-	instance = 0;
-	while (!cpu_find_by_instance(instance, NULL, &mid)) {
-		if (mid < max_cpus)
-			cpu_set(mid, phys_cpu_present_map);
-		instance++;
-	}
-
 	if (num_possible_cpus() > max_cpus) {
+		int instance, mid;
+
 		instance = 0;
 		while (!cpu_find_by_instance(instance, NULL, &mid)) {
 			if (mid != boot_cpu_id) {
@@ -1105,6 +1099,22 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	smp_store_cpu_info(boot_cpu_id);
 }
 
+/* Set this up early so that things like the scheduler can init
+ * properly.  We use the same cpu mask for both the present and
+ * possible cpu map.
+ */
+void __init smp_setup_cpu_possible_map(void)
+{
+	int instance, mid;
+
+	instance = 0;
+	while (!cpu_find_by_instance(instance, NULL, &mid)) {
+		if (mid < NR_CPUS)
+			cpu_set(mid, phys_cpu_present_map);
+		instance++;
+	}
+}
+
 void __devinit smp_prepare_boot_cpu(void)
 {
 	if (hard_smp_processor_id() >= NR_CPUS) {
diff --git a/include/asm-sparc64/smp.h b/include/asm-sparc64/smp.h
index 110a2de8912..473edb2603e 100644
--- a/include/asm-sparc64/smp.h
+++ b/include/asm-sparc64/smp.h
@@ -66,8 +66,14 @@ static __inline__ int hard_smp_processor_id(void)
 
 #define raw_smp_processor_id() (current_thread_info()->cpu)
 
+extern void smp_setup_cpu_possible_map(void);
+
 #endif /* !(__ASSEMBLY__) */
 
+#else
+
+#define smp_setup_cpu_possible_map() do { } while (0)
+
 #endif /* !(CONFIG_SMP) */
 
 #define NO_PROC_ID		0xFF
-- 
2.41.1