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Diffstat (limited to 'arch/arm/include/asm/futex.h')
-rw-r--r--arch/arm/include/asm/futex.h137
1 files changed, 90 insertions, 47 deletions
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 199a6b6de7f4..8c73900da9ed 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -3,16 +3,74 @@
#ifdef __KERNEL__
+#if defined(CONFIG_CPU_USE_DOMAINS) && defined(CONFIG_SMP)
+/* ARM doesn't provide unprivileged exclusive memory accessors */
+#include <asm-generic/futex.h>
+#else
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+#define __futex_atomic_ex_table(err_reg) \
+ "3:\n" \
+ " .pushsection __ex_table,\"a\"\n" \
+ " .align 3\n" \
+ " .long 1b, 4f, 2b, 4f\n" \
+ " .popsection\n" \
+ " .pushsection .fixup,\"ax\"\n" \
+ "4: mov %0, " err_reg "\n" \
+ " b 3b\n" \
+ " .popsection"
+
#ifdef CONFIG_SMP
-#include <asm-generic/futex.h>
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+ smp_mb(); \
+ __asm__ __volatile__( \
+ "1: ldrex %1, [%2]\n" \
+ " " insn "\n" \
+ "2: strex %1, %0, [%2]\n" \
+ " teq %1, #0\n" \
+ " bne 1b\n" \
+ " mov %0, #0\n" \
+ __futex_atomic_ex_table("%4") \
+ : "=&r" (ret), "=&r" (oldval) \
+ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
+ : "cc", "memory")
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret;
+ u32 val;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ smp_mb();
+ __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
+ "1: ldrex %1, [%4]\n"
+ " teq %1, %2\n"
+ " ite eq @ explicit IT needed for the 2b label\n"
+ "2: strexeq %0, %3, [%4]\n"
+ " movne %0, #0\n"
+ " teq %0, #0\n"
+ " bne 1b\n"
+ __futex_atomic_ex_table("%5")
+ : "=&r" (ret), "=&r" (val)
+ : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
+ : "cc", "memory");
+ smp_mb();
+
+ *uval = val;
+ return ret;
+}
#else /* !SMP, we can work around lack of atomic ops by disabling preemption */
-#include <linux/futex.h>
#include <linux/preempt.h>
-#include <linux/uaccess.h>
-#include <asm/errno.h>
#include <asm/domain.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
@@ -21,20 +79,38 @@
" " insn "\n" \
"2: " T(str) " %0, [%2]\n" \
" mov %0, #0\n" \
- "3:\n" \
- " .pushsection __ex_table,\"a\"\n" \
- " .align 3\n" \
- " .long 1b, 4f, 2b, 4f\n" \
- " .popsection\n" \
- " .pushsection .fixup,\"ax\"\n" \
- "4: mov %0, %4\n" \
- " b 3b\n" \
- " .popsection" \
+ __futex_atomic_ex_table("%4") \
: "=&r" (ret), "=&r" (oldval) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
: "cc", "memory")
static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+ u32 val;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
+ "1: " T(ldr) " %1, [%4]\n"
+ " teq %1, %2\n"
+ " it eq @ explicit IT needed for the 2b label\n"
+ "2: " T(streq) " %3, [%4]\n"
+ __futex_atomic_ex_table("%5")
+ : "+r" (ret), "=&r" (val)
+ : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
+ : "cc", "memory");
+
+ *uval = val;
+ return ret;
+}
+
+#endif /* !SMP */
+
+static inline int
futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
@@ -87,39 +163,6 @@ futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
return ret;
}
-static inline int
-futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
- u32 oldval, u32 newval)
-{
- int ret = 0;
- u32 val;
-
- if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
- return -EFAULT;
-
- __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
- "1: " T(ldr) " %1, [%4]\n"
- " teq %1, %2\n"
- " it eq @ explicit IT needed for the 2b label\n"
- "2: " T(streq) " %3, [%4]\n"
- "3:\n"
- " .pushsection __ex_table,\"a\"\n"
- " .align 3\n"
- " .long 1b, 4f, 2b, 4f\n"
- " .popsection\n"
- " .pushsection .fixup,\"ax\"\n"
- "4: mov %0, %5\n"
- " b 3b\n"
- " .popsection"
- : "+r" (ret), "=&r" (val)
- : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
- : "cc", "memory");
-
- *uval = val;
- return ret;
-}
-
-#endif /* !SMP */
-
+#endif /* !(CPU_USE_DOMAINS && SMP) */
#endif /* __KERNEL__ */
#endif /* _ASM_ARM_FUTEX_H */
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