[PATCH] x86-64: Remove apic_write_around from smpboot.c

[pandora-kernel.git] / arch / x86_64 / kernel / smpboot.c

diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 6e4807d..d4b6328 100644 (file)
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -62,13 +62,13 @@
 /* Number of siblings per CPU package */
 int smp_num_siblings = 1;
 /* Package ID of each logical CPU */
-u8 phys_proc_id[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
-u8 cpu_core_id[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
+u8 phys_proc_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
+u8 cpu_core_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
 EXPORT_SYMBOL(phys_proc_id);
 EXPORT_SYMBOL(cpu_core_id);
 
 /* Bitmask of currently online CPUs */
-cpumask_t cpu_online_map;
+cpumask_t cpu_online_map __read_mostly;
 
 EXPORT_SYMBOL(cpu_online_map);
 
@@ -88,8 +88,8 @@ struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
 /* Set when the idlers are all forked */
 int smp_threads_ready;
 
-cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
-cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
+cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
+cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(cpu_core_map);
 
 /*
@@ -334,7 +334,7 @@ static void __cpuinit tsc_sync_wait(void)
 {
        if (notscsync || !cpu_has_tsc)
                return;
-       sync_tsc(boot_cpu_id);
+       sync_tsc(0);
 }
 
 static __init int notscsync_setup(char *s)
@@ -492,6 +492,14 @@ void __cpuinit start_secondary(void)
         */
        set_cpu_sibling_map(smp_processor_id());
 
+       /* 
+        * Wait for TSC sync to not schedule things before.
+        * We still process interrupts, which could see an inconsistent
+        * time in that window unfortunately. 
+        * Do this here because TSC sync has global unprotected state.
+        */
+       tsc_sync_wait();
+
        /*
         * We need to hold call_lock, so there is no inconsistency
         * between the time smp_call_function() determines number of
@@ -509,13 +517,6 @@ void __cpuinit start_secondary(void)
        per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
        unlock_ipi_call_lock();
 
-       mb();
-
-       /* Wait for TSC sync to not schedule things before.
-          We still process interrupts, which could see an inconsistent
-          time in that window unfortunately. */
-       tsc_sync_wait();
-
        cpu_idle();
 }
 
@@ -539,8 +540,8 @@ static void inquire_remote_apic(int apicid)
                 */
                apic_wait_icr_idle();
 
-               apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
-               apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
+               apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
+               apic_write(APIC_ICR, APIC_DM_REMRD | regs[i]);
 
                timeout = 0;
                do {
@@ -573,12 +574,12 @@ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int sta
        /*
         * Turn INIT on target chip
         */
-       apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
+       apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
 
        /*
         * Send IPI
         */
-       apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
+       apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
                                | APIC_DM_INIT);
 
        Dprintk("Waiting for send to finish...\n");
@@ -594,10 +595,10 @@ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int sta
        Dprintk("Deasserting INIT.\n");
 
        /* Target chip */
-       apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
+       apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
 
        /* Send IPI */
-       apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
+       apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
 
        Dprintk("Waiting for send to finish...\n");
        timeout = 0;
@@ -639,12 +640,11 @@ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int sta
                 */
 
                /* Target chip */
-               apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
+               apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
 
                /* Boot on the stack */
                /* Kick the second */
-               apic_write_around(APIC_ICR, APIC_DM_STARTUP
-                                       | (start_rip >> 12));
+               apic_write(APIC_ICR, APIC_DM_STARTUP | (start_rip >> 12));
 
                /*
                 * Give the other CPU some time to accept the IPI.
@@ -893,23 +893,6 @@ static __init void disable_smp(void)
        cpu_set(0, cpu_core_map[0]);
 }
 
-/*
- * Handle user cpus=... parameter.
- */
-static __init void enforce_max_cpus(unsigned max_cpus)
-{
-       int i, k;
-       k = 0;
-       for (i = 0; i < NR_CPUS; i++) {
-               if (!cpu_possible(i))
-                       continue;
-               if (++k > max_cpus) {
-                       cpu_clear(i, cpu_possible_map);
-                       cpu_clear(i, cpu_present_map);
-               }
-       }
-}
-
 #ifdef CONFIG_HOTPLUG_CPU
 /*
  * cpu_possible_map should be static, it cannot change as cpu's
@@ -998,8 +981,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
        current_cpu_data = boot_cpu_data;
        current_thread_info()->cpu = 0;  /* needed? */
 
-       enforce_max_cpus(max_cpus);
-
 #ifdef CONFIG_HOTPLUG_CPU
        prefill_possible_map();
 #endif