[PATCH] Do not enforce unique IO_APIC_ID check for xAPIC systems (i386)

This patch is per Andi's request to remove NO_IOAPIC_CHECK from genapic and
use heuristics to prevent unique I/O APIC ID check for systems that don't
need it.  The patch disables unique I/O APIC ID check for Xeon-based and
other platforms that don't use serial APIC bus for interrupt delivery.
Andi stated that AMD systems don't need unique IO_APIC_IDs either.

Signed-off-by: Natalie Protasevich <Natalie.Protasevich@unisys.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 7a324e8..51f7a5d 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -1658,6 +1658,12 @@ static void __init setup_ioapic_ids_from_mpc(void)
        unsigned char old_id;
        unsigned long flags;
 
+       /*
+        * Don't check I/O APIC IDs for xAPIC systems.  They have
+        * no meaning without the serial APIC bus.
+        */
+       if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && boot_cpu_data.x86 < 15))
+               return;
        /*
         * This is broken; anything with a real cpu count has to
         * circumvent this idiocy regardless.
@@ -1684,10 +1690,6 @@ static void __init setup_ioapic_ids_from_mpc(void)
                        mp_ioapics[apic].mpc_apicid = reg_00.bits.ID;
                }
 
-               /* Don't check I/O APIC IDs for some xAPIC systems.  They have
-                * no meaning without the serial APIC bus. */
-               if (NO_IOAPIC_CHECK)
-                       continue;
                /*
                 * Sanity check, is the ID really free? Every APIC in a
                 * system must have a unique ID or we get lots of nice

diff --git a/arch/i386/kernel/mpparse.c b/arch/i386/kernel/mpparse.c
index 1347ab4..0a06105 100644 (file)
--- a/arch/i386/kernel/mpparse.c
+++ b/arch/i386/kernel/mpparse.c
@@ -914,7 +914,10 @@ void __init mp_register_ioapic (
        mp_ioapics[idx].mpc_apicaddr = address;
 
        set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
-       mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id);
+       if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 < 15))
+               mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id);
+       else
+               mp_ioapics[idx].mpc_apicid = id;
        mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx);
        
        /* 

diff --git a/include/asm-i386/genapic.h b/include/asm-i386/genapic.h
index fc813b2..b3783a3 100644 (file)
--- a/include/asm-i386/genapic.h
+++ b/include/asm-i386/genapic.h
@@ -78,7 +78,6 @@ struct genapic {
        .int_delivery_mode = INT_DELIVERY_MODE, \
        .int_dest_mode = INT_DEST_MODE, \
        .no_balance_irq = NO_BALANCE_IRQ, \
-       .no_ioapic_check = NO_IOAPIC_CHECK, \
        .ESR_DISABLE = esr_disable, \
        .apic_destination_logical = APIC_DEST_LOGICAL, \
        APICFUNC(apic_id_registered), \

diff --git a/include/asm-i386/mach-bigsmp/mach_apic.h b/include/asm-i386/mach-bigsmp/mach_apic.h
index 2339868..ba936d4 100644 (file)
--- a/include/asm-i386/mach-bigsmp/mach_apic.h
+++ b/include/asm-i386/mach-bigsmp/mach_apic.h
@@ -14,8 +14,6 @@
 #define NO_BALANCE_IRQ (1)
 #define esr_disable (1)
 
-#define NO_IOAPIC_CHECK (0)
-
 static inline int apic_id_registered(void)
 {
        return (1);

diff --git a/include/asm-i386/mach-default/mach_apic.h b/include/asm-i386/mach-default/mach_apic.h
index 627f1cd..3ef6292 100644 (file)
--- a/include/asm-i386/mach-default/mach_apic.h
+++ b/include/asm-i386/mach-default/mach_apic.h
@@ -19,8 +19,6 @@ static inline cpumask_t target_cpus(void)
 #define NO_BALANCE_IRQ (0)
 #define esr_disable (0)
 
-#define NO_IOAPIC_CHECK (0)
-
 #define INT_DELIVERY_MODE dest_LowestPrio
 #define INT_DEST_MODE 1     /* logical delivery broadcast to all procs */
 

diff --git a/include/asm-i386/mach-es7000/mach_apic.h b/include/asm-i386/mach-es7000/mach_apic.h
index ceab2c4..b5f3f0d 100644 (file)
--- a/include/asm-i386/mach-es7000/mach_apic.h
+++ b/include/asm-i386/mach-es7000/mach_apic.h
@@ -38,8 +38,6 @@ static inline cpumask_t target_cpus(void)
 #define WAKE_SECONDARY_VIA_INIT
 #endif
 
-#define NO_IOAPIC_CHECK (1)
-
 static inline unsigned long check_apicid_used(physid_mask_t bitmap, int apicid)
 { 
        return 0;

diff --git a/include/asm-i386/mach-generic/mach_apic.h b/include/asm-i386/mach-generic/mach_apic.h
index ab36d02..b13767a 100644 (file)
--- a/include/asm-i386/mach-generic/mach_apic.h
+++ b/include/asm-i386/mach-generic/mach_apic.h
@@ -5,7 +5,6 @@
 
 #define esr_disable (genapic->ESR_DISABLE)
 #define NO_BALANCE_IRQ (genapic->no_balance_irq)
-#define NO_IOAPIC_CHECK        (genapic->no_ioapic_check)
 #define INT_DELIVERY_MODE (genapic->int_delivery_mode)
 #define INT_DEST_MODE (genapic->int_dest_mode)
 #undef APIC_DEST_LOGICAL

diff --git a/include/asm-i386/mach-numaq/mach_apic.h b/include/asm-i386/mach-numaq/mach_apic.h
index e1a0449..9d15809 100644 (file)
--- a/include/asm-i386/mach-numaq/mach_apic.h
+++ b/include/asm-i386/mach-numaq/mach_apic.h
@@ -17,8 +17,6 @@ static inline cpumask_t target_cpus(void)
 #define NO_BALANCE_IRQ (1)
 #define esr_disable (1)
 
-#define NO_IOAPIC_CHECK (0)
-
 #define INT_DELIVERY_MODE dest_LowestPrio
 #define INT_DEST_MODE 0     /* physical delivery on LOCAL quad */
  

diff --git a/include/asm-i386/mach-summit/mach_apic.h b/include/asm-i386/mach-summit/mach_apic.h
index 74e9cbc..3d6d129 100644 (file)
--- a/include/asm-i386/mach-summit/mach_apic.h
+++ b/include/asm-i386/mach-summit/mach_apic.h
@@ -7,8 +7,6 @@
 #define esr_disable (1)
 #define NO_BALANCE_IRQ (0)
 
-#define NO_IOAPIC_CHECK (1)    /* Don't check I/O APIC ID for xAPIC */
-
 /* In clustered mode, the high nibble of APIC ID is a cluster number.
  * The low nibble is a 4-bit bitmap. */
 #define XAPIC_DEST_CPUS_SHIFT  4

diff --git a/include/asm-i386/mach-visws/mach_apic.h b/include/asm-i386/mach-visws/mach_apic.h
index 4e6cdfb..de438c7 100644 (file)
--- a/include/asm-i386/mach-visws/mach_apic.h
+++ b/include/asm-i386/mach-visws/mach_apic.h
@@ -9,8 +9,6 @@
 #define no_balance_irq (0)
 #define esr_disable (0)
 
-#define NO_IOAPIC_CHECK (0)
-
 #define INT_DELIVERY_MODE dest_LowestPrio
 #define INT_DEST_MODE 1     /* logical delivery broadcast to all procs */