Pull fix-cpu-possible-map into release branch

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index d2702c419cf830450ad63621bccec1e50842e718..34795ede72e0a67a49419d162862b97756d2ac9d 100644 (file)
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -761,6 +761,62 @@ int acpi_map_cpu2node(acpi_handle handle, int cpu, long physid)
        return (0);
 }
 
+int additional_cpus __initdata = -1;
+
+static __init int setup_additional_cpus(char *s)
+{
+       if (s)
+               additional_cpus = simple_strtol(s, NULL, 0);
+
+       return 0;
+}
+
+early_param("additional_cpus", setup_additional_cpus);
+
+/*
+ * cpu_possible_map should be static, it cannot change as cpu's
+ * are onlined, or offlined. The reason is per-cpu data-structures
+ * are allocated by some modules at init time, and dont expect to
+ * do this dynamically on cpu arrival/departure.
+ * cpu_present_map on the other hand can change dynamically.
+ * In case when cpu_hotplug is not compiled, then we resort to current
+ * behaviour, which is cpu_possible == cpu_present.
+ * - Ashok Raj
+ *
+ * Three ways to find out the number of additional hotplug CPUs:
+ * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
+ * - The user can overwrite it with additional_cpus=NUM
+ * - Otherwise don't reserve additional CPUs.
+ */
+__init void prefill_possible_map(void)
+{
+       int i;
+       int possible, disabled_cpus;
+
+       disabled_cpus = total_cpus - available_cpus;
+       if (additional_cpus == -1) {
+               if (disabled_cpus > 0) {
+                       possible = total_cpus;
+                       additional_cpus = disabled_cpus;
+               }
+               else {
+                       possible = available_cpus;
+                       additional_cpus = 0;
+               }
+       } else {
+               possible = available_cpus + additional_cpus;
+       }
+       if (possible > NR_CPUS)
+               possible = NR_CPUS;
+
+       printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
+               possible,
+               max_t(int, additional_cpus, 0));
+
+       for (i = 0; i < possible; i++)
+               cpu_set(i, cpu_possible_map);
+}
+
 int acpi_map_lsapic(acpi_handle handle, int *pcpu)
 {
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 35f7835294a38bc10bff199ec3c6e8d78f4485b6..3258e09278d07ca440c77b211e4cc67f3c5c4616 100644 (file)
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -430,6 +430,7 @@ setup_arch (char **cmdline_p)
        if (early_console_setup(*cmdline_p) == 0)
                mark_bsp_online();
 
+       parse_early_param();
 #ifdef CONFIG_ACPI
        /* Initialize the ACPI boot-time table parser */
        acpi_table_init();
@@ -688,6 +689,9 @@ void
 setup_per_cpu_areas (void)
 {
        /* start_kernel() requires this... */
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+       prefill_possible_map();
+#endif
 }
 
 /*

diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index 8f44e7d2df66eb8e0d052132ab8fe7a390587212..b681ef34a86e13a5ecab3a7e1ec2eb6b7378e847 100644 (file)
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -129,7 +129,7 @@ DEFINE_PER_CPU(int, cpu_state);
 /* Bitmasks of currently online, and possible CPUs */
 cpumask_t cpu_online_map;
 EXPORT_SYMBOL(cpu_online_map);
-cpumask_t cpu_possible_map;
+cpumask_t cpu_possible_map = CPU_MASK_NONE;
 EXPORT_SYMBOL(cpu_possible_map);
 
 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
@@ -506,9 +506,6 @@ smp_build_cpu_map (void)
 
        for (cpu = 0; cpu < NR_CPUS; cpu++) {
                ia64_cpu_to_sapicid[cpu] = -1;
-#ifdef CONFIG_HOTPLUG_CPU
-               cpu_set(cpu, cpu_possible_map);
-#endif
        }
 
        ia64_cpu_to_sapicid[0] = boot_cpu_id;

diff --git a/include/asm-ia64/acpi.h b/include/asm-ia64/acpi.h
index 3a544ffc500860f5f1c166e3e2b9bff57e7e11b5..f7a517654308e03f4c0ee880dc5cb88fbfaad615 100644 (file)
--- a/include/asm-ia64/acpi.h
+++ b/include/asm-ia64/acpi.h
@@ -106,6 +106,8 @@ extern unsigned int can_cpei_retarget(void);
 extern unsigned int is_cpu_cpei_target(unsigned int cpu);
 extern void set_cpei_target_cpu(unsigned int cpu);
 extern unsigned int get_cpei_target_cpu(void);
+extern void prefill_possible_map(void);
+extern int additional_cpus;
 
 #ifdef CONFIG_ACPI_NUMA
 /* Proximity bitmap length; _PXM is at most 255 (8 bit)*/