1 files changed, 121 insertions, 3 deletions
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 6a332a9f099c..9ee743b95de8 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -1,6 +1,124 @@
-#ifndef _ASM_FUTEX_H
+#ifndef _ASM_ARM_FUTEX_H
-#define _ASM_FUTEX_H
+#define _ASM_ARM_FUTEX_H
+#ifdef __KERNEL__
+#ifdef CONFIG_SMP
 #include <asm-generic/futex.h>
-#endif
+#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>
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)      \
+        __asm__ __volatile__(                                   \
+        "1:     ldrt    %1, [%2]\n"                             \
+        "       " insn "\n"                                     \
+        "2:     strt    %0, [%2]\n"                             \
+        "       mov     %0, #0\n"                               \
+        "3:\n"                                                  \
+        "       .section __ex_table,\"a\"\n"                    \
+        "       .align  3\n"                                    \
+        "       .long   1b, 4f, 2b, 4f\n"                       \
+        "       .previous\n"                                    \
+        "       .section .fixup,\"ax\"\n"                       \
+        "4:     mov     %0, %4\n"                               \
+        "       b       3b\n"                                   \
+        "       .previous"                                      \
+        : "=&r" (ret), "=&r" (oldval)                           \
+        : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT)              \
+        : "cc", "memory")
+static inline int
+futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+{
+        int op = (encoded_op >> 28) & 7;
+        int cmp = (encoded_op >> 24) & 15;
+        int oparg = (encoded_op << 8) >> 20;
+        int cmparg = (encoded_op << 20) >> 20;
+        int oldval = 0, ret;
+        if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+                oparg = 1 << oparg;
+        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+                return -EFAULT;
+        pagefault_disable();    /* implies preempt_disable() */
+        switch (op) {
+        case FUTEX_OP_SET:
+                __futex_atomic_op("mov  %0, %3", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_ADD:
+                __futex_atomic_op("add  %0, %1, %3", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_OR:
+                __futex_atomic_op("orr  %0, %1, %3", ret, oldval, uaddr, oparg);
+                break;
+        case FUTEX_OP_ANDN:
+                __futex_atomic_op("and  %0, %1, %3", ret, oldval, uaddr, ~oparg);
+                break;
+        case FUTEX_OP_XOR:
+                __futex_atomic_op("eor  %0, %1, %3", ret, oldval, uaddr, oparg);
+                break;
+        default:
+                ret = -ENOSYS;
+        }
+        pagefault_enable();     /* subsumes preempt_enable() */
+        if (!ret) {
+                switch (cmp) {
+                case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+                case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+                case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+                case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+                case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+                case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+                default: ret = -ENOSYS;
+                }
+        }
+        return ret;
+}
+static inline int
+futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+{
+        int val;
+        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+                return -EFAULT;
+        pagefault_disable();    /* implies preempt_disable() */
+        __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
+        "1:     ldrt    %0, [%3]\n"
+        "       teq     %0, %1\n"
+        "2:     streqt  %2, [%3]\n"
+        "3:\n"
+        "       .section __ex_table,\"a\"\n"
+        "       .align  3\n"
+        "       .long   1b, 4f, 2b, 4f\n"
+        "       .previous\n"
+        "       .section .fixup,\"ax\"\n"
+        "4:     mov     %0, %4\n"
+        "       b       3b\n"
+        "       .previous"
+        : "=&r" (val)
+        : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
+        : "cc", "memory");
+        pagefault_enable();     /* subsumes preempt_enable() */
+        return val;
+}
+#endif /* !SMP */
+#endif /* __KERNEL__ */
+#endif /* _ASM_ARM_FUTEX_H */

diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index 6a332a9f099c..9ee743b95de8 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h
@@ -1,6 +1,124 @@
1	#ifndef _ASM_FUTEX_H	1	#ifndef _ASM_ARM_FUTEX_H
2	#define _ASM_FUTEX_H	2	#define _ASM_ARM_FUTEX_H
		3
		4	#ifdef __KERNEL__
		5
		6	#ifdef CONFIG_SMP
3		7
4	#include <asm-generic/futex.h>	8	#include <asm-generic/futex.h>
5		9
6	#endif	10	#else /* !SMP, we can work around lack of atomic ops by disabling preemption */
		11
		12	#include <linux/futex.h>
		13	#include <linux/preempt.h>
		14	#include <linux/uaccess.h>
		15	#include <asm/errno.h>
		16
		17	#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
		18	__asm__ __volatile__( \
		19	"1: ldrt %1, [%2]\n" \
		20	" " insn "\n" \
		21	"2: strt %0, [%2]\n" \
		22	" mov %0, #0\n" \
		23	"3:\n" \
		24	" .section __ex_table,\"a\"\n" \
		25	" .align 3\n" \
		26	" .long 1b, 4f, 2b, 4f\n" \
		27	" .previous\n" \
		28	" .section .fixup,\"ax\"\n" \
		29	"4: mov %0, %4\n" \
		30	" b 3b\n" \
		31	" .previous" \
		32	: "=&r" (ret), "=&r" (oldval) \
		33	: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
		34	: "cc", "memory")
		35
		36	static inline int
		37	futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
		38	{
		39	int op = (encoded_op >> 28) & 7;
		40	int cmp = (encoded_op >> 24) & 15;
		41	int oparg = (encoded_op << 8) >> 20;
		42	int cmparg = (encoded_op << 20) >> 20;
		43	int oldval = 0, ret;
		44
		45	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
		46	oparg = 1 << oparg;
		47
		48	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
		49	return -EFAULT;
		50
		51	pagefault_disable(); /* implies preempt_disable() */
		52
		53	switch (op) {
		54	case FUTEX_OP_SET:
		55	__futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
		56	break;
		57	case FUTEX_OP_ADD:
		58	__futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
		59	break;
		60	case FUTEX_OP_OR:
		61	__futex_atomic_op("orr %0, %1, %3", ret, oldval, uaddr, oparg);
		62	break;
		63	case FUTEX_OP_ANDN:
		64	__futex_atomic_op("and %0, %1, %3", ret, oldval, uaddr, ~oparg);
		65	break;
		66	case FUTEX_OP_XOR:
		67	__futex_atomic_op("eor %0, %1, %3", ret, oldval, uaddr, oparg);
		68	break;
		69	default:
		70	ret = -ENOSYS;
		71	}
		72
		73	pagefault_enable(); /* subsumes preempt_enable() */
		74
		75	if (!ret) {
		76	switch (cmp) {
		77	case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
		78	case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
		79	case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
		80	case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
		81	case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
		82	case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
		83	default: ret = -ENOSYS;
		84	}
		85	}
		86	return ret;
		87	}
		88
		89	static inline int
		90	futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
		91	{
		92	int val;
		93
		94	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
		95	return -EFAULT;
		96
		97	pagefault_disable(); /* implies preempt_disable() */
		98
		99	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
		100	"1: ldrt %0, [%3]\n"
		101	" teq %0, %1\n"
		102	"2: streqt %2, [%3]\n"
		103	"3:\n"
		104	" .section __ex_table,\"a\"\n"
		105	" .align 3\n"
		106	" .long 1b, 4f, 2b, 4f\n"
		107	" .previous\n"
		108	" .section .fixup,\"ax\"\n"
		109	"4: mov %0, %4\n"
		110	" b 3b\n"
		111	" .previous"
		112	: "=&r" (val)
		113	: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
		114	: "cc", "memory");
		115
		116	pagefault_enable(); /* subsumes preempt_enable() */
		117
		118	return val;
		119	}
		120
		121	#endif /* !SMP */
		122
		123	#endif /* __KERNEL__ */
		124	#endif /* _ASM_ARM_FUTEX_H */