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authorMichal Simek <monstr@monstr.eu>2009-10-19 11:58:44 +0200
committerMichal Simek <monstr@monstr.eu>2009-12-14 08:45:04 +0100
commitfd3db0a675a35f28b08e47e8ed1a7a7f158467c2 (patch)
tree723eeb48b518fdb53ab83523fe68147513eaa6f4
parentd68bf9705ad490ad86b0b1be9a2b91a363d6eccc (diff)
downloadop-kernel-dev-fd3db0a675a35f28b08e47e8ed1a7a7f158467c2.zip
op-kernel-dev-fd3db0a675a35f28b08e47e8ed1a7a7f158467c2.tar.gz
microblaze: Futex support
Microblaze v7.20 provides new lwx, swx instructions which bring possibility to implement lock rutines. There are some tests in open posix thread LTP part but current toolchain not support it. Signed-off-by: Michal Simek <monstr@monstr.eu>
-rw-r--r--arch/microblaze/include/asm/futex.h127
1 files changed, 126 insertions, 1 deletions
diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h
index 0b74582..8dbb6e7 100644
--- a/arch/microblaze/include/asm/futex.h
+++ b/arch/microblaze/include/asm/futex.h
@@ -1 +1,126 @@
-#include <asm-generic/futex.h>
+#ifndef _ASM_MICROBLAZE_FUTEX_H
+#define _ASM_MICROBLAZE_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+({ \
+ __asm__ __volatile__ ( \
+ "1: lwx %0, %2, r0; " \
+ insn \
+ "2: swx %1, %2, r0; \
+ addic %1, r0, 0; \
+ bnei %1, 1b; \
+ 3: \
+ .section .fixup,\"ax\"; \
+ 4: brid 3b; \
+ addik %1, r0, %3; \
+ .previous; \
+ .section __ex_table,\"a\"; \
+ .word 1b,4b,2b,4b; \
+ .previous;" \
+ : "=&r" (oldval), "=&r" (ret) \
+ : "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
+ ); \
+})
+
+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();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("and %1,%0,%4;", ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ pagefault_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 prev, cmp;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+ return -EFAULT;
+
+ __asm__ __volatile__ ("1: lwx %0, %2, r0; \
+ cmp %1, %0, %3; \
+ beqi %1, 3f; \
+ 2: swx %4, %2, r0; \
+ addic %1, r0, 0; \
+ bnei %1, 1b; \
+ 3: \
+ .section .fixup,\"ax\"; \
+ 4: brid 3b; \
+ addik %0, r0, %5; \
+ .previous; \
+ .section __ex_table,\"a\"; \
+ .word 1b,4b,2b,4b; \
+ .previous;" \
+ : "=&r" (prev), "=&r"(cmp) \
+ : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
+
+ return prev;
+}
+
+#endif /* __KERNEL__ */
+
+#endif
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