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-rw-r--r--arch/parisc/include/asm/futex.h154
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h
new file mode 100644
index 000000000..49df14805
--- /dev/null
+++ b/arch/parisc/include/asm/futex.h
@@ -0,0 +1,154 @@
+#ifndef _ASM_PARISC_FUTEX_H
+#define _ASM_PARISC_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/atomic.h>
+#include <asm/errno.h>
+
+/* The following has to match the LWS code in syscall.S. We have
+ sixteen four-word locks. */
+
+static inline void
+_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags)
+{
+ extern u32 lws_lock_start[];
+ long index = ((long)uaddr & 0xf0) >> 2;
+ arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
+ local_irq_save(*flags);
+ arch_spin_lock(s);
+}
+
+static inline void
+_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags)
+{
+ extern u32 lws_lock_start[];
+ long index = ((long)uaddr & 0xf0) >> 2;
+ arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
+ arch_spin_unlock(s);
+ local_irq_restore(*flags);
+}
+
+static inline int
+futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
+{
+ unsigned long int flags;
+ u32 val;
+ 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(*uaddr)))
+ return -EFAULT;
+
+ pagefault_disable();
+
+ _futex_spin_lock_irqsave(uaddr, &flags);
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ /* *(int *)UADDR2 = OPARG; */
+ ret = get_user(oldval, uaddr);
+ if (!ret)
+ ret = put_user(oparg, uaddr);
+ break;
+ case FUTEX_OP_ADD:
+ /* *(int *)UADDR2 += OPARG; */
+ ret = get_user(oldval, uaddr);
+ if (!ret) {
+ val = oldval + oparg;
+ ret = put_user(val, uaddr);
+ }
+ break;
+ case FUTEX_OP_OR:
+ /* *(int *)UADDR2 |= OPARG; */
+ ret = get_user(oldval, uaddr);
+ if (!ret) {
+ val = oldval | oparg;
+ ret = put_user(val, uaddr);
+ }
+ break;
+ case FUTEX_OP_ANDN:
+ /* *(int *)UADDR2 &= ~OPARG; */
+ ret = get_user(oldval, uaddr);
+ if (!ret) {
+ val = oldval & ~oparg;
+ ret = put_user(val, uaddr);
+ }
+ break;
+ case FUTEX_OP_XOR:
+ /* *(int *)UADDR2 ^= OPARG; */
+ ret = get_user(oldval, uaddr);
+ if (!ret) {
+ val = oldval ^ oparg;
+ ret = put_user(val, uaddr);
+ }
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ _futex_spin_unlock_irqrestore(uaddr, &flags);
+
+ 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;
+}
+
+/* Non-atomic version */
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret;
+ u32 val;
+ unsigned long flags;
+
+ /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
+ * our gateway page, and causes no end of trouble...
+ */
+ if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
+ return -EFAULT;
+
+ if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+ return -EFAULT;
+
+ /* HPPA has no cmpxchg in hardware and therefore the
+ * best we can do here is use an array of locks. The
+ * lock selected is based on a hash of the userspace
+ * address. This should scale to a couple of CPUs.
+ */
+
+ _futex_spin_lock_irqsave(uaddr, &flags);
+
+ ret = get_user(val, uaddr);
+
+ if (!ret && val == oldval)
+ ret = put_user(newval, uaddr);
+
+ *uval = val;
+
+ _futex_spin_unlock_irqrestore(uaddr, &flags);
+
+ return ret;
+}
+
+#endif /*__KERNEL__*/
+#endif /*_ASM_PARISC_FUTEX_H*/