[PATCH v4 2/6] arm64/xen: introduce asm/xen header files on arm64

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

asm/xen/hypercall.h, asm/xen/hypervisor.h, asm/xen/interface.h and
asm/xen/page.h are identical so to avoid code duplication we are just
including the original arm header files here.

asm/xen/events.h is slightly different, so introduce a different file
here (use xchg to implement xchg_xen_ulong and pass regs->pstate to
raw_irqs_disabled_flags).

Also introduce asm/hypervisor.h and asm/sync_bitops.h.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

Change in v2:
- add all the required headers in this patch, by including the original
  arch/arm headers when possible to avoid code duplication;
- use xchg to implement xchg_xen_ulong.
---
 arch/arm64/include/asm/hypervisor.h     |    6 ++++++
 arch/arm64/include/asm/sync_bitops.h    |   26 ++++++++++++++++++++++++++
 arch/arm64/include/asm/xen/events.h     |   21 +++++++++++++++++++++
 arch/arm64/include/asm/xen/hypercall.h  |    1 +
 arch/arm64/include/asm/xen/hypervisor.h |    1 +
 arch/arm64/include/asm/xen/interface.h  |    1 +
 arch/arm64/include/asm/xen/page.h       |    1 +
 7 files changed, 57 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm64/include/asm/hypervisor.h
 create mode 100644 arch/arm64/include/asm/sync_bitops.h
 create mode 100644 arch/arm64/include/asm/xen/events.h
 create mode 100644 arch/arm64/include/asm/xen/hypercall.h
 create mode 100644 arch/arm64/include/asm/xen/hypervisor.h
 create mode 100644 arch/arm64/include/asm/xen/interface.h
 create mode 100644 arch/arm64/include/asm/xen/page.h

diff --git a/arch/arm64/include/asm/hypervisor.h b/arch/arm64/include/asm/hypervisor.h
new file mode 100644
index 0000000..d2c7904
--- /dev/null
+++ b/arch/arm64/include/asm/hypervisor.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_ARM64_HYPERVISOR_H
+#define _ASM_ARM64_HYPERVISOR_H
+
+#include <asm/xen/hypervisor.h>
+
+#endif
diff --git a/arch/arm64/include/asm/sync_bitops.h b/arch/arm64/include/asm/sync_bitops.h
new file mode 100644
index 0000000..8da0bf4
--- /dev/null
+++ b/arch/arm64/include/asm/sync_bitops.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_SYNC_BITOPS_H__
+#define __ASM_SYNC_BITOPS_H__
+
+#include <asm/bitops.h>
+#include <asm/cmpxchg.h>
+
+/* sync_bitops functions are equivalent to the SMP implementation of the
+ * original functions, independently from CONFIG_SMP being defined.
+ *
+ * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
+ * under Xen you might be communicating with a completely external entity
+ * who might be on another CPU (e.g. two uniprocessor guests communicating
+ * via event channels and grant tables). So we need a variant of the bit
+ * ops which are SMP safe even on a UP kernel.
+ */
+
+#define sync_set_bit(nr, p)            set_bit(nr, p)
+#define sync_clear_bit(nr, p)          clear_bit(nr, p)
+#define sync_change_bit(nr, p)         change_bit(nr, p)
+#define sync_test_and_set_bit(nr, p)   test_and_set_bit(nr, p)
+#define sync_test_and_clear_bit(nr, p) test_and_clear_bit(nr, p)
+#define sync_test_and_change_bit(nr, p)        test_and_change_bit(nr, p)
+#define sync_test_bit(nr, addr)                test_bit(nr, addr)
+#define sync_cmpxchg                   cmpxchg
+
+#endif
diff --git a/arch/arm64/include/asm/xen/events.h b/arch/arm64/include/asm/xen/events.h
new file mode 100644
index 0000000..8655321
--- /dev/null
+++ b/arch/arm64/include/asm/xen/events.h
@@ -0,0 +1,21 @@
+#ifndef _ASM_ARM64_XEN_EVENTS_H
+#define _ASM_ARM64_XEN_EVENTS_H
+
+#include <asm/ptrace.h>
+#include <asm/atomic.h>
+
+enum ipi_vector {
+	XEN_PLACEHOLDER_VECTOR,
+
+	/* Xen IPIs go here */
+	XEN_NR_IPIS,
+};
+
+static inline int xen_irqs_disabled(struct pt_regs *regs)
+{
+	return raw_irqs_disabled_flags((unsigned long) regs->pstate);
+}
+
+#define xchg_xen_ulong(ptr, val) xchg((ptr), (val))
+
+#endif /* _ASM_ARM64_XEN_EVENTS_H */
diff --git a/arch/arm64/include/asm/xen/hypercall.h b/arch/arm64/include/asm/xen/hypercall.h
new file mode 100644
index 0000000..74b0c42
--- /dev/null
+++ b/arch/arm64/include/asm/xen/hypercall.h
@@ -0,0 +1 @@
+#include <../../arm/include/asm/xen/hypercall.h>
diff --git a/arch/arm64/include/asm/xen/hypervisor.h b/arch/arm64/include/asm/xen/hypervisor.h
new file mode 100644
index 0000000..f263da8
--- /dev/null
+++ b/arch/arm64/include/asm/xen/hypervisor.h
@@ -0,0 +1 @@
+#include <../../arm/include/asm/xen/hypervisor.h>
diff --git a/arch/arm64/include/asm/xen/interface.h b/arch/arm64/include/asm/xen/interface.h
new file mode 100644
index 0000000..44457ae
--- /dev/null
+++ b/arch/arm64/include/asm/xen/interface.h
@@ -0,0 +1 @@
+#include <../../arm/include/asm/xen/interface.h>
diff --git a/arch/arm64/include/asm/xen/page.h b/arch/arm64/include/asm/xen/page.h
new file mode 100644
index 0000000..bed87ec
--- /dev/null
+++ b/arch/arm64/include/asm/xen/page.h
@@ -0,0 +1 @@
+#include <../../arm/include/asm/xen/page.h>
-- 
1.7.2.5