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authorArnd Bergmann <arnd@arndb.de>2012-10-04 22:57:00 +0200
committerArnd Bergmann <arnd@arndb.de>2012-10-04 22:57:51 +0200
commitc37d6154c0b9163c27e53cc1d0be3867b4abd760 (patch)
tree7a24522c56d1cb284dff1d3c225bbdaba0901bb5 /arch/arm64/include/asm/cmpxchg.h
parente7a570ff7dff9af6e54ff5e580a61ec7652137a0 (diff)
parent8a1ab3155c2ac7fbe5f2038d6e26efeb607a1498 (diff)
Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic
Patches from David Howells <dhowells@redhat.com>: This is to complete part of the UAPI disintegration for which the preparatory patches were pulled recently. Note that there are some fixup patches which are at the base of the branch aimed at you, plus all arches get the asm-generic branch merged in too. * 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers: UAPI: (Scripted) Disintegrate include/asm-generic UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k) c6x: remove c6x signal.h UAPI: Split compound conditionals containing __KERNEL__ in Arm64 UAPI: Fix the guards on various asm/unistd.h files Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm64/include/asm/cmpxchg.h')
-rw-r--r--arch/arm64/include/asm/cmpxchg.h173
1 files changed, 173 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
new file mode 100644
index 00000000000..e0e65b069d9
--- /dev/null
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -0,0 +1,173 @@
+/*
+ * Based on arch/arm/include/asm/cmpxchg.h
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <linux/bug.h>
+
+#include <asm/barrier.h>
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
+{
+ unsigned long ret, tmp;
+
+ switch (size) {
+ case 1:
+ asm volatile("// __xchg1\n"
+ "1: ldaxrb %w0, [%3]\n"
+ " stlxrb %w1, %w2, [%3]\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ case 2:
+ asm volatile("// __xchg2\n"
+ "1: ldaxrh %w0, [%3]\n"
+ " stlxrh %w1, %w2, [%3]\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ case 4:
+ asm volatile("// __xchg4\n"
+ "1: ldaxr %w0, [%3]\n"
+ " stlxr %w1, %w2, [%3]\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ case 8:
+ asm volatile("// __xchg8\n"
+ "1: ldaxr %0, [%3]\n"
+ " stlxr %w1, %2, [%3]\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (x), "r" (ptr)
+ : "memory", "cc");
+ break;
+ default:
+ BUILD_BUG();
+ }
+
+ return ret;
+}
+
+#define xchg(ptr,x) \
+ ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long oldval = 0, res;
+
+ switch (size) {
+ case 1:
+ do {
+ asm volatile("// __cmpxchg1\n"
+ " ldxrb %w1, [%2]\n"
+ " mov %w0, #0\n"
+ " cmp %w1, %w3\n"
+ " b.ne 1f\n"
+ " stxrb %w0, %w4, [%2]\n"
+ "1:\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "cc");
+ } while (res);
+ break;
+
+ case 2:
+ do {
+ asm volatile("// __cmpxchg2\n"
+ " ldxrh %w1, [%2]\n"
+ " mov %w0, #0\n"
+ " cmp %w1, %w3\n"
+ " b.ne 1f\n"
+ " stxrh %w0, %w4, [%2]\n"
+ "1:\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "memory", "cc");
+ } while (res);
+ break;
+
+ case 4:
+ do {
+ asm volatile("// __cmpxchg4\n"
+ " ldxr %w1, [%2]\n"
+ " mov %w0, #0\n"
+ " cmp %w1, %w3\n"
+ " b.ne 1f\n"
+ " stxr %w0, %w4, [%2]\n"
+ "1:\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "cc");
+ } while (res);
+ break;
+
+ case 8:
+ do {
+ asm volatile("// __cmpxchg8\n"
+ " ldxr %1, [%2]\n"
+ " mov %w0, #0\n"
+ " cmp %1, %3\n"
+ " b.ne 1f\n"
+ " stxr %w0, %4, [%2]\n"
+ "1:\n"
+ : "=&r" (res), "=&r" (oldval)
+ : "r" (ptr), "Ir" (old), "r" (new)
+ : "cc");
+ } while (res);
+ break;
+
+ default:
+ BUILD_BUG();
+ }
+
+ return oldval;
+}
+
+static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long ret;
+
+ smp_mb();
+ ret = __cmpxchg(ptr, old, new, size);
+ smp_mb();
+
+ return ret;
+}
+
+#define cmpxchg(ptr,o,n) \
+ ((__typeof__(*(ptr)))__cmpxchg_mb((ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n), \
+ sizeof(*(ptr))))
+
+#define cmpxchg_local(ptr,o,n) \
+ ((__typeof__(*(ptr)))__cmpxchg((ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n), \
+ sizeof(*(ptr))))
+
+#endif /* __ASM_CMPXCHG_H */