[PATCH] i386: Consolidate modern APIC handling

AMD systems have a modern APIC that supports 8 bit IDs, but
don't have a XAPIC version number.  Add a new "modern_apic"
subfunction that handles this correctly and use it (nearly)
everywhere where XAPIC is tested for.

I removed one wart: the code specified that external APICs
would use an 8bit APIC ID. But I checked a real 82093 data sheet
and it says clearly that they only use 4bit. So I removed
this special case since it would a bit awkward to implement now.

I removed the valid APIC tests in mptable parsing completely. On any modern
system they only check against the full field width (8bit) anyways
and are no-ops. This also fixes them doing the wrong thing
on >8 core Opterons.

This makes i386 boot again on 16 core Opterons.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 18 insertions, 28 deletions

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 6273bf74c20..254cee9f0b7 100644
--- 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);
 
+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.
@@ -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.
diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c
index 8d8aa9d1796..db120174aa7 100644
--- a/arch/i386/kernel/mpparse.c
+++ b/arch/i386/kernel/mpparse.c
@@ -110,21 +110,6 @@ static int __init mpf_checksum(unsigned char *mp, int len)
 static int mpc_record; 
 static struct mpc_config_translation *translation_table[MAX_MPC_ENTRY] __initdata;
 
-#ifdef CONFIG_X86_NUMAQ
-static int MP_valid_apicid(int apicid, int version)
-{
-        return hweight_long(apicid & 0xf) == 1 && (apicid >> 4) != 0xf;
-}
-#else
-static int MP_valid_apicid(int apicid, int version)
-{
-        if (version >= 0x14)
-                return apicid < 0xff;
-        else
-                return apicid < 0xf;
-}
-#endif
-
 static void __devinit MP_processor_info (struct mpc_config_processor *m)
 {
         int ver, apicid;
@@ -190,12 +175,6 @@ static void __devinit MP_processor_info (struct mpc_config_processor *m)
 
         ver = m->mpc_apicver;
 
-        if (!MP_valid_apicid(apicid, ver)) {
-                printk(KERN_WARNING "Processor #%d INVALID. (Max ID: %d).\n",
-                        m->mpc_apicid, MAX_APICS);
-                return;
-        }
-
         /*
          * Validate version
          */
diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
index ff9ac8d19eb..288233fd77d 100644
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -139,6 +139,8 @@ void switch_ipi_to_APIC_timer(void *cpumask);
 
 extern int timer_over_8254;
 
+extern int modern_apic(void);
+
 #else /* !CONFIG_X86_LOCAL_APIC */
 static inline void lapic_shutdown(void) { }