x64, x2apic/intr-remap: basic apic ops support

Introduce basic apic operations which handle the apic programming. This
will be used later to introduce another specific operations for x2apic.

For the perfomance critial accesses like IPI's, EOI etc, we use the
native operations as they are already referenced by different
indirections like genapic, irq_chip etc.

64bit Paravirt ops can also define their apic operations accordingly.

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>

1 files changed, 32 insertions, 2 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 3963f590c3d4..9bb040689b31 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -119,13 +119,13 @@ static int modern_apic(void)
 	return lapic_get_version() >= 0x14;
 }
 
-void apic_wait_icr_idle(void)
+void xapic_wait_icr_idle(void)
 {
 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
 		cpu_relax();
 }
 
-u32 safe_apic_wait_icr_idle(void)
+u32 safe_xapic_wait_icr_idle(void)
 {
 	u32 send_status;
 	int timeout;
@@ -141,6 +141,36 @@ u32 safe_apic_wait_icr_idle(void)
 	return send_status;
 }
 
+void xapic_icr_write(u32 low, u32 id)
+{
+	apic_write(APIC_ICR2, id << 24);
+	apic_write(APIC_ICR, low);
+}
+
+u64 xapic_icr_read(void)
+{
+	u32 icr1, icr2;
+
+	icr2 = apic_read(APIC_ICR2);
+	icr1 = apic_read(APIC_ICR);
+
+	return (icr1 | ((u64)icr2 << 32));
+}
+
+static struct apic_ops xapic_ops = {
+	.read = native_apic_mem_read,
+	.write = native_apic_mem_write,
+	.write_atomic = native_apic_mem_write_atomic,
+	.icr_read = xapic_icr_read,
+	.icr_write = xapic_icr_write,
+	.wait_icr_idle = xapic_wait_icr_idle,
+	.safe_wait_icr_idle = safe_xapic_wait_icr_idle,
+};
+
+struct apic_ops __read_mostly *apic_ops = &xapic_ops;
+
+EXPORT_SYMBOL_GPL(apic_ops);
+
 /**
  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
  */