x64, x2apic/intr-remap: x2apic ops for x2apic mode support

x2apic ops for x2apic mode support. This uses MSR interface and differs
slightly from the xapic register layout.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic_64.c

@@ -171,6 +171,41 @@ struct apic_ops __read_mostly *apic_ops = &xapic_ops;
 
 EXPORT_SYMBOL_GPL(apic_ops);
 
+static void x2apic_wait_icr_idle(void)
+{
+	/* no need to wait for icr idle in x2apic */
+	return;
+}
+
+static u32 safe_x2apic_wait_icr_idle(void)
+{
+	/* no need to wait for icr idle in x2apic */
+	return 0;
+}
+
+void x2apic_icr_write(u32 low, u32 id)
+{
+	wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
+}
+
+u64 x2apic_icr_read(void)
+{
+	unsigned long val;
+
+	rdmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), val);
+	return val;
+}
+
+static struct apic_ops x2apic_ops = {
+	.read = native_apic_msr_read,
+	.write = native_apic_msr_write,
+	.write_atomic = native_apic_msr_write,
+	.icr_read = x2apic_icr_read,
+	.icr_write = x2apic_icr_write,
+	.wait_icr_idle = x2apic_wait_icr_idle,
+	.safe_wait_icr_idle = safe_x2apic_wait_icr_idle,
+};
+
 /**
  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
  */

include/asm-x86/apic.h

@@ -7,6 +7,8 @@
 #include <asm/apicdef.h>
 #include <asm/processor.h>
 #include <asm/system.h>
+#include <asm/cpufeature.h>
+#include <asm/msr.h>
 
 #define ARCH_APICTIMER_STOPS_ON_C3	1
 
@@ -73,6 +75,26 @@ static inline u32 native_apic_mem_read(u32 reg)
 	return *((volatile u32 *)(APIC_BASE + reg));
 }
 
+static inline void native_apic_msr_write(u32 reg, u32 v)
+{
+	if (reg == APIC_DFR || reg == APIC_ID || reg == APIC_LDR ||
+	    reg == APIC_LVR)
+		return;
+
+	wrmsr(APIC_BASE_MSR + (reg >> 4), v, 0);
+}
+
+static inline u32 native_apic_msr_read(u32 reg)
+{
+	u32 low, high;
+
+	if (reg == APIC_DFR)
+		return -1;
+
+	rdmsr(APIC_BASE_MSR + (reg >> 4), low, high);
+	return low;
+}
+
 #ifdef CONFIG_X86_32
 extern void apic_wait_icr_idle(void);
 extern u32 safe_apic_wait_icr_idle(void);

include/asm-x86/apicdef.h

@@ -105,6 +105,7 @@
 #define	APIC_TMICT	0x380
 #define	APIC_TMCCT	0x390
 #define	APIC_TDCR	0x3E0
+#define APIC_SELF_IPI	0x3F0
 #define		APIC_TDR_DIV_TMBASE	(1 << 2)
 #define		APIC_TDR_DIV_1		0xB
 #define		APIC_TDR_DIV_2		0x0
@@ -128,6 +129,8 @@
 #define	APIC_EILVT3     0x530
 
 #define APIC_BASE (fix_to_virt(FIX_APIC_BASE))
+#define APIC_BASE_MSR	0x800
+#define X2APIC_ENABLE	(1UL << 10)
 
 #ifdef CONFIG_X86_32
 # define MAX_IO_APICS 64