Merge tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "There are three ARM compile fixes (we forgot to export certain
  functions and if the drivers are built as an module - we go belly-up).

  There is also an mismatch of irq_enter() / exit_idle() calls sequence
  which were fixed some time ago in other piece of codes, but failed to
  appear in the Xen code.

  Lastly a fix for to help in the field with troubleshooting in case we
  cannot get the appropriate parameter and also fallback code when
  working with very old hypervisors."

Bug-fixes:
 - Fix compile issues on ARM.
 - Fix hypercall fallback code for old hypervisors.
 - Print out which HVM parameter failed if it fails.
 - Fix idle notifier call after irq_enter.

* tag 'stable/for-linus-3.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/arm: Fix compile errors when drivers are compiled as modules (export more).
  xen/arm: Fix compile errors when drivers are compiled as modules.
  xen/generic: Disable fallback build on ARM.
  xen/events: fix RCU warning, or Call idle notifier after irq_enter()
  xen/hvm: If we fail to fetch an HVM parameter print out which flag it is.
  xen/hypercall: fix hypercall fallback code for very old hypervisors

3 files changed, 82 insertions, 1 deletions

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 0e8637035457..74354708c6c4 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -2,6 +2,7 @@ ifneq ($(CONFIG_ARM),y)
 obj-y   += manage.o balloon.o
 obj-$(CONFIG_HOTPLUG_CPU)               += cpu_hotplug.o
 endif
+obj-$(CONFIG_X86)                       += fallback.o
 obj-y   += grant-table.o features.o events.o
 obj-y   += xenbus/
 
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 912ac81b6dbf..0be4df39e953 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1395,10 +1395,10 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 {
         struct pt_regs *old_regs = set_irq_regs(regs);
 
+        irq_enter();
 #ifdef CONFIG_X86
         exit_idle();
 #endif
-        irq_enter();
 
         __xen_evtchn_do_upcall();
 
diff --git a/drivers/xen/fallback.c b/drivers/xen/fallback.c
new file mode 100644
index 000000000000..0ef7c4d40f86
--- /dev/null
+++ b/drivers/xen/fallback.c
@@ -0,0 +1,80 @@
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <asm/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+int xen_event_channel_op_compat(int cmd, void *arg)
+{
+        struct evtchn_op op;
+        int rc;
+
+        op.cmd = cmd;
+        memcpy(&op.u, arg, sizeof(op.u));
+        rc = _hypercall1(int, event_channel_op_compat, &op);
+
+        switch (cmd) {
+        case EVTCHNOP_close:
+        case EVTCHNOP_send:
+        case EVTCHNOP_bind_vcpu:
+        case EVTCHNOP_unmask:
+                /* no output */
+                break;
+
+#define COPY_BACK(eop) \
+        case EVTCHNOP_##eop: \
+                memcpy(arg, &op.u.eop, sizeof(op.u.eop)); \
+                break
+
+        COPY_BACK(bind_interdomain);
+        COPY_BACK(bind_virq);
+        COPY_BACK(bind_pirq);
+        COPY_BACK(status);
+        COPY_BACK(alloc_unbound);
+        COPY_BACK(bind_ipi);
+#undef COPY_BACK
+
+        default:
+                WARN_ON(rc != -ENOSYS);
+                break;
+        }
+
+        return rc;
+}
+EXPORT_SYMBOL_GPL(xen_event_channel_op_compat);
+
+int HYPERVISOR_physdev_op_compat(int cmd, void *arg)
+{
+        struct physdev_op op;
+        int rc;
+
+        op.cmd = cmd;
+        memcpy(&op.u, arg, sizeof(op.u));
+        rc = _hypercall1(int, physdev_op_compat, &op);
+
+        switch (cmd) {
+        case PHYSDEVOP_IRQ_UNMASK_NOTIFY:
+        case PHYSDEVOP_set_iopl:
+        case PHYSDEVOP_set_iobitmap:
+        case PHYSDEVOP_apic_write:
+                /* no output */
+                break;
+
+#define COPY_BACK(pop, fld) \
+        case PHYSDEVOP_##pop: \
+                memcpy(arg, &op.u.fld, sizeof(op.u.fld)); \
+                break
+
+        COPY_BACK(irq_status_query, irq_status_query);
+        COPY_BACK(apic_read, apic_op);
+        COPY_BACK(ASSIGN_VECTOR, irq_op);
+#undef COPY_BACK
+
+        default:
+                WARN_ON(rc != -ENOSYS);
+                break;
+        }
+
+        return rc;
+}