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Message-ID: <1369930713-6063-4-git-send-email-stefano.stabellini@eu.citrix.com>
Date: Thu, 30 May 2013 17:18:31 +0100
From: Stefano Stabellini <stefano.stabellini@...citrix.com>
To: <linux-arm-kernel@...ts.infradead.org>
CC: <linux-kernel@...r.kernel.org>, <xen-devel@...ts.xensource.com>,
<Stefano.Stabellini@...citrix.com>, <will.deacon@....com>,
<catalin.marinas@....com>, <Ian.Campbell@...rix.com>,
<konrad.wilk@...cle.com>,
Stefano Stabellini <stefano.stabellini@...citrix.com>
Subject: [PATCH RFC 4/6] arm64/xen: introduce asm/hypervisor.h and sys_bitops.h
Signed-off-by: Stefano Stabellini <stefano.stabellini@...citrix.com>
---
arch/arm64/include/asm/hypervisor.h | 6 ++++++
arch/arm64/include/asm/sync_bitops.h | 26 ++++++++++++++++++++++++++
2 files changed, 32 insertions(+), 0 deletions(-)
create mode 100644 arch/arm64/include/asm/hypervisor.h
create mode 100644 arch/arm64/include/asm/sync_bitops.h
diff --git a/arch/arm64/include/asm/hypervisor.h b/arch/arm64/include/asm/hypervisor.h
new file mode 100644
index 0000000..b90d9e5
--- /dev/null
+++ b/arch/arm64/include/asm/hypervisor.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_ARM_HYPERVISOR_H
+#define _ASM_ARM_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
--
1.7.2.5
--
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