--- /dev/null
+/*
+ * 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 <linux/mmdebug.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: ldxrb %w0, %2\n"
+ " stlxrb %w1, %w3, %2\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)
+ : "r" (x)
+ : "memory");
+ break;
+ case 2:
+ asm volatile("// __xchg2\n"
+ "1: ldxrh %w0, %2\n"
+ " stlxrh %w1, %w3, %2\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp), "+Q" (*(u16 *)ptr)
+ : "r" (x)
+ : "memory");
+ break;
+ case 4:
+ asm volatile("// __xchg4\n"
+ "1: ldxr %w0, %2\n"
+ " stlxr %w1, %w3, %2\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp), "+Q" (*(u32 *)ptr)
+ : "r" (x)
+ : "memory");
+ break;
+ case 8:
+ asm volatile("// __xchg8\n"
+ "1: ldxr %0, %2\n"
+ " stlxr %w1, %3, %2\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (ret), "=&r" (tmp), "+Q" (*(u64 *)ptr)
+ : "r" (x)
+ : "memory");
+ break;
+ default:
+ BUILD_BUG();
+ }
+
+ smp_mb();
+ return ret;
+}
+
+#define xchg(ptr,x) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __ret = (__typeof__(*(ptr))) \
+ __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))); \
+ __ret; \
+})
+
+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), "+Q" (*(u8 *)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), "+Q" (*(u16 *)ptr)
+ : "Ir" (old), "r" (new)
+ : "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), "+Q" (*(u32 *)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), "+Q" (*(u64 *)ptr)
+ : "Ir" (old), "r" (new)
+ : "cc");
+ } while (res);
+ break;
+
+ default:
+ BUILD_BUG();
+ }
+
+ return oldval;
+}
+
+#define system_has_cmpxchg_double() 1
+
+static inline int __cmpxchg_double(volatile void *ptr1, volatile void *ptr2,
+ unsigned long old1, unsigned long old2,
+ unsigned long new1, unsigned long new2, int size)
+{
+ unsigned long loop, lost;
+
+ switch (size) {
+ case 8:
+ VM_BUG_ON((unsigned long *)ptr2 - (unsigned long *)ptr1 != 1);
+ do {
+ asm volatile("// __cmpxchg_double8\n"
+ " ldxp %0, %1, %2\n"
+ " eor %0, %0, %3\n"
+ " eor %1, %1, %4\n"
+ " orr %1, %0, %1\n"
+ " mov %w0, #0\n"
+ " cbnz %1, 1f\n"
+ " stxp %w0, %5, %6, %2\n"
+ "1:\n"
+ : "=&r"(loop), "=&r"(lost), "+Q" (*(u64 *)ptr1)
+ : "r" (old1), "r"(old2), "r"(new1), "r"(new2));
+ } while (loop);
+ break;
+ default:
+ BUILD_BUG();
+ }
+
+ return !lost;
+}
+
+static inline int __cmpxchg_double_mb(volatile void *ptr1, volatile void *ptr2,
+ unsigned long old1, unsigned long old2,
+ unsigned long new1, unsigned long new2, int size)
+{
+ int ret;
+
+ smp_mb();
+ ret = __cmpxchg_double(ptr1, ptr2, old1, old2, new1, new2, size);
+ smp_mb();
+
+ return ret;
+}
+
+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)) __ret; \
+ __ret = (__typeof__(*(ptr))) \
+ __cmpxchg_mb((ptr), (unsigned long)(o), (unsigned long)(n), \
+ sizeof(*(ptr))); \
+ __ret; \
+})
+
+#define cmpxchg_local(ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __ret = (__typeof__(*(ptr))) \
+ __cmpxchg((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))); \
+ __ret; \
+})
+
+#define cmpxchg_double(ptr1, ptr2, o1, o2, n1, n2) \
+({\
+ int __ret;\
+ __ret = __cmpxchg_double_mb((ptr1), (ptr2), (unsigned long)(o1), \
+ (unsigned long)(o2), (unsigned long)(n1), \
+ (unsigned long)(n2), sizeof(*(ptr1)));\
+ __ret; \
+})
+
+#define cmpxchg_double_local(ptr1, ptr2, o1, o2, n1, n2) \
+({\
+ int __ret;\
+ __ret = __cmpxchg_double((ptr1), (ptr2), (unsigned long)(o1), \
+ (unsigned long)(o2), (unsigned long)(n1), \
+ (unsigned long)(n2), sizeof(*(ptr1)));\
+ __ret; \
+})
+
+#define _protect_cmpxchg_local(pcp, o, n) \
+({ \
+ typeof(*raw_cpu_ptr(&(pcp))) __ret; \
+ preempt_disable(); \
+ __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
+ preempt_enable(); \
+ __ret; \
+})
+
+#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+
+#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
+({ \
+ int __ret; \
+ preempt_disable(); \
+ __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \
+ raw_cpu_ptr(&(ptr2)), \
+ o1, o2, n1, n2); \
+ preempt_enable(); \
+ __ret; \
+})
+
+#define cmpxchg64(ptr,o,n) cmpxchg((ptr),(o),(n))
+#define cmpxchg64_local(ptr,o,n) cmpxchg_local((ptr),(o),(n))
+
+#define cmpxchg64_relaxed(ptr,o,n) cmpxchg_local((ptr),(o),(n))
+
+#endif /* __ASM_CMPXCHG_H */
Code Review / kvmfornfv.git / blobdiff