[PATCH] alpha: SMP IRQ routing fix

From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

After removal of fixup_cpu_present_map() function Alpha ended up with an empty
cpu_present_map, so secondary CPUs on SMP systems are not being started.

Worse, on some platforms we route interrupts to secondary CPUs using
cpu_possible_map which is still populated properly.  As a result, these
interrupts go nowhere so the machines like DP264 aren't able to boot even with
a primary CPU.

Fixed basically by s/cpu_present_mask/cpu_present_map/.

Thanks to Ernst Herzberg for reporting the bug and testing the fix.

Cc: Ernst Herzberg <list-lkml@net4u.de>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 9 insertions, 18 deletions

diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
index c645c5e14786..2b245ad731ee 100644
--- a/arch/alpha/kernel/alpha_ksyms.c
+++ b/arch/alpha/kernel/alpha_ksyms.c
@@ -182,7 +182,6 @@ EXPORT_SYMBOL(smp_num_cpus);
 EXPORT_SYMBOL(smp_call_function);
 EXPORT_SYMBOL(smp_call_function_on_cpu);
 EXPORT_SYMBOL(_atomic_dec_and_lock);
-EXPORT_SYMBOL(cpu_present_mask);
 #endif /* CONFIG_SMP */
 
 /*
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 9924fd07743a..c760a831fd1a 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -94,7 +94,7 @@ common_shutdown_1(void *generic_ptr)
         if (cpuid != boot_cpuid) {
                 flags |= 0x00040000UL; /* "remain halted" */
                 *pflags = flags;
-                clear_bit(cpuid, &cpu_present_mask);
+                cpu_clear(cpuid, cpu_present_map);
                 halt();
         }
 #endif
@@ -120,8 +120,8 @@ common_shutdown_1(void *generic_ptr)
 
 #ifdef CONFIG_SMP
         /* Wait for the secondaries to halt. */
-        cpu_clear(boot_cpuid, cpu_possible_map);
-        while (cpus_weight(cpu_possible_map))
+        cpu_clear(boot_cpuid, cpu_present_map);
+        while (cpus_weight(cpu_present_map))
                 barrier();
 #endif
 
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 185255416e85..4dc273e537fd 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -68,7 +68,6 @@ enum ipi_message_type {
 static int smp_secondary_alive __initdata = 0;
 
 /* Which cpus ids came online.  */
-cpumask_t cpu_present_mask;
 cpumask_t cpu_online_map;
 
 EXPORT_SYMBOL(cpu_online_map);
@@ -439,7 +438,7 @@ setup_smp(void)
                         if ((cpu->flags & 0x1cc) == 0x1cc) {
                                 smp_num_probed++;
                                 /* Assume here that "whami" == index */
-                                cpu_set(i, cpu_present_mask);
+                                cpu_set(i, cpu_present_map);
                                 cpu->pal_revision = boot_cpu_palrev;
                         }
 
@@ -450,11 +449,10 @@ setup_smp(void)
                 }
         } else {
                 smp_num_probed = 1;
-                cpu_set(boot_cpuid, cpu_present_mask);
         }
 
-        printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
-               smp_num_probed, cpu_possible_map.bits[0]);
+        printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_map = %lx\n",
+               smp_num_probed, cpu_present_map.bits[0]);
 }
 
 /*
@@ -473,7 +471,7 @@ smp_prepare_cpus(unsigned int max_cpus)
 
         /* Nothing to do on a UP box, or when told not to.  */
         if (smp_num_probed == 1 || max_cpus == 0) {
-                cpu_present_mask = cpumask_of_cpu(boot_cpuid);
+                cpu_present_map = cpumask_of_cpu(boot_cpuid);
                 printk(KERN_INFO "SMP mode deactivated.\n");
                 return;
         }
@@ -486,10 +484,6 @@ smp_prepare_cpus(unsigned int max_cpus)
 void __devinit
 smp_prepare_boot_cpu(void)
 {
-        /*
-         * Mark the boot cpu (current cpu) as online
-         */ 
-        cpu_set(smp_processor_id(), cpu_online_map);
 }
 
 int __devinit
diff --git a/arch/alpha/kernel/sys_titan.c b/arch/alpha/kernel/sys_titan.c
index 5f84417eeb7b..2551fb49ae09 100644
--- a/arch/alpha/kernel/sys_titan.c
+++ b/arch/alpha/kernel/sys_titan.c
@@ -66,7 +66,7 @@ titan_update_irq_hw(unsigned long mask)
         register int bcpu = boot_cpuid;
 
 #ifdef CONFIG_SMP
-        cpumask_t cpm = cpu_present_mask;
+        cpumask_t cpm = cpu_present_map;
         volatile unsigned long *dim0, *dim1, *dim2, *dim3;
         unsigned long mask0, mask1, mask2, mask3, dummy;
 
diff --git a/include/asm-alpha/smp.h b/include/asm-alpha/smp.h
index 9950706abdf8..e1432102be05 100644
--- a/include/asm-alpha/smp.h
+++ b/include/asm-alpha/smp.h
@@ -45,10 +45,8 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS];
 #define hard_smp_processor_id() __hard_smp_processor_id()
 #define raw_smp_processor_id()  (current_thread_info()->cpu)
 
-extern cpumask_t cpu_present_mask;
-extern cpumask_t cpu_online_map;
 extern int smp_num_cpus;
-#define cpu_possible_map        cpu_present_mask
+#define cpu_possible_map        cpu_present_map
 
 int smp_call_function_on_cpu(void (*func) (void *info), void *info,int retry, int wait, cpumask_t cpu);