[MIPS] SMP: Fix initialization order bug.

    
A recent change requires cpu_possible_map to be initialized before
smp_sched_init() but most MIPS platforms were initializing their
processors in the prom_prepare_cpus callback of smp_prepare_cpus.  The
simple fix of calling prom_prepare_cpus from one of the earlier SMP
initialization hooks doesn't work well either since IPIs may require
init_IRQ() to have completed, so bit the bullet and split
prom_prepare_cpus into two initialization functions, plat_smp_setup
which is called early from setup_arch and plat_prepare_cpus called where
prom_prepare_cpus used to be called.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 11 insertions, 7 deletions

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index d86affa21278..d9293c558e41 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -540,6 +540,9 @@ void __init setup_arch(char **cmdline_p)
         sparse_init();
         paging_init();
         resource_init();
+#ifdef CONFIG_SMP
+        plat_smp_setup();
+#endif
 }
 
 int __init fpu_disable(char *s)
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 5e189862e523..06ed90752424 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -236,7 +236,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
         init_new_context(current, &init_mm);
         current_thread_info()->cpu = 0;
         smp_tune_scheduling();
-        prom_prepare_cpus(max_cpus);
+        plat_prepare_cpus(max_cpus);
 }
 
 /* preload SMP state for boot cpu */
diff --git a/arch/mips/kernel/smp_mt.c b/arch/mips/kernel/smp_mt.c
index c930364830d0..993b8bf56aaf 100644
--- a/arch/mips/kernel/smp_mt.c
+++ b/arch/mips/kernel/smp_mt.c
@@ -143,7 +143,7 @@ static struct irqaction irq_call = {
  * Make sure all CPU's are in a sensible state before we boot any of the
  * secondarys
  */
-void prom_prepare_cpus(unsigned int max_cpus)
+void plat_smp_setup(void)
 {
         unsigned long val;
         int i, num;
@@ -179,11 +179,9 @@ void prom_prepare_cpus(unsigned int max_cpus)
                                 write_vpe_c0_vpeconf0(tmp);
 
                                 /* Record this as available CPU */
-                                if (i < max_cpus) {
-                                        cpu_set(i, phys_cpu_present_map);
-                                        __cpu_number_map[i]     = ++num;
-                                        __cpu_logical_map[num]  = i;
-                                }
+                                cpu_set(i, phys_cpu_present_map);
+                                __cpu_number_map[i]     = ++num;
+                                __cpu_logical_map[num]  = i;
                         }
 
                         /* disable multi-threading with TC's */
@@ -241,7 +239,10 @@ void prom_prepare_cpus(unsigned int max_cpus)
                 set_vi_handler (MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
                 set_vi_handler (MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
         }
+}
 
+void __init plat_prepare_cpus(unsigned int max_cpus)
+{
         cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
         cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;