[PATCH] x86: sutomatically enable bigsmp when we have more than 8 CPUs
Venkatesh Pallipadi [Sat, 3 Sep 2005 22:56:31 +0000 (15:56 -0700)]
i386 generic subarchitecture requires explicit dmi strings or command line
to enable bigsmp mode.  The patch below removes that restriction, and uses
bigsmp as soon as it finds more than 8 logical CPUs, Intel processors and
xAPIC support.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/acpi/boot.c
arch/i386/kernel/mpparse.c
arch/i386/kernel/setup.c
arch/i386/mach-generic/bigsmp.c
arch/i386/mach-generic/probe.c
include/asm-i386/apicdef.h
include/asm-i386/mach-generic/mach_apic.h
include/asm-i386/mpspec.h

index b7808a8..34ee500 100644 (file)
@@ -833,6 +833,9 @@ acpi_process_madt(void)
                if (!error) {
                        acpi_lapic = 1;
 
+#ifdef CONFIG_X86_GENERICARCH
+                       generic_bigsmp_probe();
+#endif
                        /*
                         * Parse MADT IO-APIC entries
                         */
index ce838ab..788efff 100644 (file)
@@ -65,6 +65,8 @@ int nr_ioapics;
 int pic_mode;
 unsigned long mp_lapic_addr;
 
+unsigned int def_to_bigsmp = 0;
+
 /* Processor that is doing the boot up */
 unsigned int boot_cpu_physical_apicid = -1U;
 /* Internal processor count */
@@ -213,6 +215,13 @@ static void __init MP_processor_info (struct mpc_config_processor *m)
                ver = 0x10;
        }
        apic_version[m->mpc_apicid] = ver;
+       if ((num_processors > 8) &&
+           APIC_XAPIC(ver) &&
+           (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL))
+               def_to_bigsmp = 1;
+       else
+               def_to_bigsmp = 0;
+
        bios_cpu_apicid[num_processors - 1] = m->mpc_apicid;
 }
 
index 9adbf71..294bcca 100644 (file)
@@ -1585,8 +1585,14 @@ void __init setup_arch(char **cmdline_p)
         */
        acpi_boot_table_init();
        acpi_boot_init();
-#endif
 
+#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
+       if (def_to_bigsmp)
+               printk(KERN_WARNING "More than 8 CPUs detected and "
+                       "CONFIG_X86_PC cannot handle it.\nUse "
+                       "CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
+#endif
+#endif
 #ifdef CONFIG_X86_LOCAL_APIC
        if (smp_found_config)
                get_smp_config();
index 25883b4..037b2af 100644 (file)
@@ -47,7 +47,10 @@ static struct dmi_system_id __initdata bigsmp_dmi_table[] = {
 
 static __init int probe_bigsmp(void)
 { 
-       dmi_check_system(bigsmp_dmi_table);
+       if (def_to_bigsmp)
+               dmi_bigsmp = 1;
+       else
+               dmi_check_system(bigsmp_dmi_table);
        return dmi_bigsmp; 
 } 
 
index 5497c65..cea5b3c 100644 (file)
@@ -30,6 +30,25 @@ struct genapic *apic_probe[] __initdata = {
        NULL,
 };
 
+static int cmdline_apic;
+
+void __init generic_bigsmp_probe(void)
+{
+       /*
+        * This routine is used to switch to bigsmp mode when
+        * - There is no apic= option specified by the user
+        * - generic_apic_probe() has choosen apic_default as the sub_arch
+        * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
+        */
+
+       if (!cmdline_apic && genapic == &apic_default)
+               if (apic_bigsmp.probe()) {
+                       genapic = &apic_bigsmp;
+                       printk(KERN_INFO "Overriding APIC driver with %s\n",
+                              genapic->name);
+               }
+}
+
 void __init generic_apic_probe(char *command_line) 
 { 
        char *s;
@@ -52,6 +71,7 @@ void __init generic_apic_probe(char *command_line)
                if (!changed)
                        printk(KERN_ERR "Unknown genapic `%s' specified.\n", s);
                *p = old;
+               cmdline_apic = changed;
        } 
        for (i = 0; !changed && apic_probe[i]; i++) { 
                if (apic_probe[i]->probe()) {
index a96a8f4..03185ce 100644 (file)
@@ -16,6 +16,7 @@
 #define                        GET_APIC_VERSION(x)     ((x)&0xFF)
 #define                        GET_APIC_MAXLVT(x)      (((x)>>16)&0xFF)
 #define                        APIC_INTEGRATED(x)      ((x)&0xF0)
+#define                        APIC_XAPIC(x)           ((x) >= 0x14)
 #define                APIC_TASKPRI    0x80
 #define                        APIC_TPRI_MASK          0xFF
 #define                APIC_ARBPRI     0x90
index b13767a..d9dc039 100644 (file)
@@ -28,4 +28,6 @@
 #define enable_apic_mode (genapic->enable_apic_mode)
 #define phys_pkg_id (genapic->phys_pkg_id)
 
+extern void generic_bigsmp_probe(void);
+
 #endif /* __ASM_MACH_APIC_H */
index d9fafba..d84a9c3 100644 (file)
@@ -11,6 +11,7 @@ extern int mp_bus_id_to_local [MAX_MP_BUSSES];
 extern int quad_local_to_mp_bus_id [NR_CPUS/4][4];
 extern int mp_bus_id_to_pci_bus [MAX_MP_BUSSES];
 
+extern unsigned int def_to_bigsmp;
 extern unsigned int boot_cpu_physical_apicid;
 extern int smp_found_config;
 extern void find_smp_config (void);