x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs

We need to fall back from logical-flat APIC mode to physical-flat mode
when we have more than 8 CPUs.  However, in the presence of CPU
hotplug(with bios listing not enabled but possible cpus as disabled cpus in
MADT), we have to consider the number of possible CPUs rather than
the number of current CPUs; otherwise we may cross the 8-CPU boundary
when CPUs are added later.

32bit apic code can use more cleanups (like the removal of vendor checks in
32bit default_setup_apic_routing()) and more unifications with 64bit code.
Yinghai has some patches in works already. This patch addresses the boot issue
that is reported in the virtualization guest context.

[ hpa: incorporated function annotation feedback from Yinghai Lu ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1265767304.2833.19.camel@sbs-t61.sc.intel.com>
Acked-by: Shaohui Zheng <shaohui.zheng@intel.com>
Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 036d28adf59d15336b5a1acc7f754609cb21aded..0acbcdfa5ca43d5533b8ec42939e7d05888e2cc4 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1185,9 +1185,6 @@ static void __init acpi_process_madt(void)
                if (!error) {
                        acpi_lapic = 1;
 
-#ifdef CONFIG_X86_BIGSMP
-                       generic_bigsmp_probe();
-#endif
                        /*
                         * Parse MADT IO-APIC entries
                         */
@@ -1197,8 +1194,6 @@ static void __init acpi_process_madt(void)
                                acpi_ioapic = 1;
 
                                smp_found_config = 1;
-                               if (apic->setup_apic_routing)
-                                       apic->setup_apic_routing();
                        }
                }
                if (error == -EINVAL) {

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 3987e4408f75fc02266eb8ae805aef9831155f59..dfca210f6a10c7af86a5dc0eac5ebf2241bf0949 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1641,9 +1641,7 @@ int __init APIC_init_uniprocessor(void)
 #endif
 
        enable_IR_x2apic();
-#ifdef CONFIG_X86_64
        default_setup_apic_routing();
-#endif
 
        verify_local_APIC();
        connect_bsp_APIC();
@@ -1891,21 +1889,6 @@ void __cpuinit generic_processor_info(int apicid, int version)
        if (apicid > max_physical_apicid)
                max_physical_apicid = apicid;
 
-#ifdef CONFIG_X86_32
-       if (num_processors > 8) {
-               switch (boot_cpu_data.x86_vendor) {
-               case X86_VENDOR_INTEL:
-                       if (!APIC_XAPIC(version)) {
-                               def_to_bigsmp = 0;
-                               break;
-                       }
-                       /* If P4 and above fall through */
-               case X86_VENDOR_AMD:
-                       def_to_bigsmp = 1;
-               }
-       }
-#endif
-
 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
        early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
        early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;

diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1a6559f6768c063af1e31c0a04a4bf60f591b3e4..99d2fe01608420bef1646f206a476ae4a8e3ba26 100644 (file)
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -52,7 +52,32 @@ static int __init print_ipi_mode(void)
 }
 late_initcall(print_ipi_mode);
 
-void default_setup_apic_routing(void)
+void __init default_setup_apic_routing(void)
+{
+       int version = apic_version[boot_cpu_physical_apicid];
+
+       if (num_possible_cpus() > 8) {
+               switch (boot_cpu_data.x86_vendor) {
+               case X86_VENDOR_INTEL:
+                       if (!APIC_XAPIC(version)) {
+                               def_to_bigsmp = 0;
+                               break;
+                       }
+                       /* If P4 and above fall through */
+               case X86_VENDOR_AMD:
+                       def_to_bigsmp = 1;
+               }
+       }
+
+#ifdef CONFIG_X86_BIGSMP
+       generic_bigsmp_probe();
+#endif
+
+       if (apic->setup_apic_routing)
+               apic->setup_apic_routing();
+}
+
+static void setup_apic_flat_routing(void)
 {
 #ifdef CONFIG_X86_IO_APIC
        printk(KERN_INFO
@@ -103,7 +128,7 @@ struct apic apic_default = {
        .init_apic_ldr                  = default_init_apic_ldr,
 
        .ioapic_phys_id_map             = default_ioapic_phys_id_map,
-       .setup_apic_routing             = default_setup_apic_routing,
+       .setup_apic_routing             = setup_apic_flat_routing,
        .multi_timer_check              = NULL,
        .apicid_to_node                 = default_apicid_to_node,
        .cpu_to_logical_apicid          = default_cpu_to_logical_apicid,

diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index 450fe2064a1411909b53e2e6ca818d446c4bca78..83e9be4778e2b597791306a85ca9ca527003e2c2 100644 (file)
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -67,7 +67,7 @@ void __init default_setup_apic_routing(void)
        }
 #endif
 
-       if (apic == &apic_flat && num_processors > 8)
+       if (apic == &apic_flat && num_possible_cpus() > 8)
                        apic = &apic_physflat;
 
        printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 40b54ceb68b560dc61ec81b5d7222298057bb133..a2c1edd2d3acdaf3dc4dfd9cb9b8abc41c56e2ad 100644 (file)
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -359,13 +359,6 @@ static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
                x86_init.mpparse.mpc_record(1);
        }
 
-#ifdef CONFIG_X86_BIGSMP
-       generic_bigsmp_probe();
-#endif
-
-       if (apic->setup_apic_routing)
-               apic->setup_apic_routing();
-
        if (!num_processors)
                printk(KERN_ERR "MPTABLE: no processors registered!\n");
        return num_processors;

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 678d0b8c26f3152c67a833f3e782cb15c9d0a61b..b4e870cbdc60eb1244b74c2b5c1bb83fc766fd17 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1083,9 +1083,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
        set_cpu_sibling_map(0);
 
        enable_IR_x2apic();
-#ifdef CONFIG_X86_64
        default_setup_apic_routing();
-#endif
 
        if (smp_sanity_check(max_cpus) < 0) {
                printk(KERN_INFO "SMP disabled\n");