Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/apic changes from Ingo Molnar:
 "Most of the changes are about helping virtualized guest kernels
  achieve better performance."

Fix up trivial conflicts with the iommu updates to arch/x86/kernel/apic/io_apic.c

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Implement EIO micro-optimization
  x86/apic: Add apic->eoi_write() callback
  x86/apic: Use symbolic APIC_EOI_ACK
  x86/apic: Fix typo EIO_ACK -> EOI_ACK and document it
  x86/xen/apic: Add missing #include <xen/xen.h>
  x86/apic: Only compile local function if used with !CONFIG_GENERIC_PENDING_IRQ
  x86/apic: Fix UP boot crash
  x86: Conditionally update time when ack-ing pending irqs
  xen/apic: implement io apic read with hypercall
  Revert "xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'"
  xen/x86: Implement x86_apic_ops
  x86/apic: Replace io_apic_ops with x86_io_apic_ops.

5 files changed, 41 insertions, 4 deletions

diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index add2c2d..96ab2c0 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -20,5 +20,5 @@ obj-$(CONFIG_EVENT_TRACING) += trace.o
 obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
 obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
-obj-$(CONFIG_XEN_DOM0)		+= vga.o
+obj-$(CONFIG_XEN_DOM0)		+= apic.o vga.o
 obj-$(CONFIG_SWIOTLB_XEN)	+= pci-swiotlb-xen.o
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
new file mode 100644
index 0000000..ec57bd3
--- /dev/null
+++ b/arch/x86/xen/apic.c
@@ -0,0 +1,33 @@
+#include <linux/init.h>
+
+#include <asm/x86_init.h>
+#include <asm/apic.h>
+#include <asm/xen/hypercall.h>
+
+#include <xen/xen.h>
+#include <xen/interface/physdev.h>
+
+unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
+{
+	struct physdev_apic apic_op;
+	int ret;
+
+	apic_op.apic_physbase = mpc_ioapic_addr(apic);
+	apic_op.reg = reg;
+	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
+	if (!ret)
+		return apic_op.value;
+
+	/* fallback to return an emulated IO_APIC values */
+	if (reg == 0x1)
+		return 0x00170020;
+	else if (reg == 0x0)
+		return apic << 24;
+
+	return 0xfd;
+}
+
+void __init xen_init_apic(void)
+{
+	x86_io_apic_ops.read = xen_io_apic_read;
+}
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 95dccce..c0f5fac 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1396,6 +1396,8 @@ asmlinkage void __init xen_start_kernel(void)
 		xen_start_info->console.domU.mfn = 0;
 		xen_start_info->console.domU.evtchn = 0;
 
+		xen_init_apic();
+
 		/* Make sure ACS will be enabled */
 		pci_request_acs();
 	}
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 69f5857..3506cd4 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1864,7 +1864,6 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
 #endif	/* CONFIG_X86_64 */
 
 static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss;
-static unsigned char fake_ioapic_mapping[PAGE_SIZE] __page_aligned_bss;
 
 static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 {
@@ -1905,7 +1904,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
 		 * We just don't map the IO APIC - all access is via
 		 * hypercalls.  Keep the address in the pte for reference.
 		 */
-		pte = pfn_pte(PFN_DOWN(__pa(fake_ioapic_mapping)), PAGE_KERNEL);
+		pte = pfn_pte(PFN_DOWN(__pa(dummy_mapping)), PAGE_KERNEL);
 		break;
 #endif
 
@@ -2070,7 +2069,6 @@ void __init xen_init_mmu_ops(void)
 	pv_mmu_ops = xen_mmu_ops;
 
 	memset(dummy_mapping, 0xff, PAGE_SIZE);
-	memset(fake_ioapic_mapping, 0xfd, PAGE_SIZE);
 }
 
 /* Protected by xen_reservation_lock. */
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index b095739..45c0c06 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -92,11 +92,15 @@ struct dom0_vga_console_info;
 
 #ifdef CONFIG_XEN_DOM0
 void __init xen_init_vga(const struct dom0_vga_console_info *, size_t size);
+void __init xen_init_apic(void);
 #else
 static inline void __init xen_init_vga(const struct dom0_vga_console_info *info,
 				       size_t size)
 {
 }
+static inline void __init xen_init_apic(void)
+{
+}
 #endif
 
 /* Declare an asm function, along with symbols needed to make it