[PATCH] Time: i386 Conversion - part 2: Rework TSC Support

[safe/jmp/linux-2.6] / arch / i386 / kernel / apic.c

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 6273bf7..5ab59c1 100644 (file)
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -62,6 +62,18 @@ int apic_verbosity;
 
 static void apic_pm_activate(void);
 
+static int modern_apic(void)
+{
+       unsigned int lvr, version;
+       /* AMD systems use old APIC versions, so check the CPU */
+       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+               boot_cpu_data.x86 >= 0xf)
+               return 1;
+       lvr = apic_read(APIC_LVR);
+       version = GET_APIC_VERSION(lvr);
+       return version >= 0x14;
+}
+
 /*
  * 'what should we do if we get a hw irq event on an illegal vector'.
  * each architecture has to answer this themselves.
@@ -101,7 +113,7 @@ void __init apic_intr_init(void)
 }
 
 /* Using APIC to generate smp_local_timer_interrupt? */
-int using_apic_timer = 0;
+int using_apic_timer __read_mostly = 0;
 
 static int enabled_via_apicbase;
 
@@ -119,10 +131,7 @@ void enable_NMI_through_LVT0 (void * dummy)
 
 int get_physical_broadcast(void)
 {
-       unsigned int lvr, version;
-       lvr = apic_read(APIC_LVR);
-       version = GET_APIC_VERSION(lvr);
-       if (!APIC_INTEGRATED(version) || version >= 0x14)
+       if (modern_apic())
                return 0xff;
        else
                return 0xf;
@@ -349,9 +358,9 @@ int __init verify_local_APIC(void)
 
 void __init sync_Arb_IDs(void)
 {
-       /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
-       unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
-       if (ver >= 0x14)        /* P4 or higher */
+       /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1
+          And not needed on AMD */
+       if (modern_apic())
                return;
        /*
         * Wait for idle.
@@ -748,10 +757,6 @@ static int __init apic_set_verbosity(char *str)
                apic_verbosity = APIC_DEBUG;
        else if (strcmp("verbose", str) == 0)
                apic_verbosity = APIC_VERBOSE;
-       else
-               printk(KERN_WARNING "APIC Verbosity level %s not recognised"
-                               " use apic=verbose or apic=debug\n", str);
-
        return 1;
 }
 
@@ -1336,6 +1341,14 @@ int __init APIC_init_uniprocessor (void)
 
        connect_bsp_APIC();
 
+       /*
+        * Hack: In case of kdump, after a crash, kernel might be booting
+        * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
+        * might be zero if read from MP tables. Get it from LAPIC.
+        */
+#ifdef CONFIG_CRASH_DUMP
+       boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
+#endif
        phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
 
        setup_local_APIC();