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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-06-04 15:07:03 +0400
committerStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-06-07 14:39:45 +0400
commit9f54ad6652d454b6a8e932b5307e60c9023bd974 (patch)
treec1bb0ef6771134652eef5fe07a4023078f7c2907 /arch/arm64/include/asm/sync_bitops.h
parentf0a8d597913bba310a519a149294b835b6c8c9c5 (diff)
downloadlinux-9f54ad6652d454b6a8e932b5307e60c9023bd974.tar.xz
arm64/xen: introduce asm/xen header files on arm64
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>
Diffstat (limited to 'arch/arm64/include/asm/sync_bitops.h')
-rw-r--r--arch/arm64/include/asm/sync_bitops.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/sync_bitops.h b/arch/arm64/include/asm/sync_bitops.h
new file mode 100644
index 000000000000..8da0bf4f7659
--- /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