[parisc-linux] Non-atomic __set_bit
Carlos O'Donell Jr.
carlos@megatonmonkey.net
Mon, 24 Sep 2001 02:10:54 -0400
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parisc,
Walking the source for devfs and thinking about Alberts problem.
Would the non-working devfs be fixed by adding:
Non-atomic versions of set_bit e.g. __set_bit
and test_and_set_bit e.g. __test_and_set_bit
to linux/include/asm-parisc/bitops.h?
I have the latest CVS linux module.
I've patched against that. It compiles now ;)
(god bless make -j8)
I'm currently sleepy, but I'll post the patch, and test
it tommorow on a 712/60 and 715/50.
c.
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--- ./linux/include/asm-parisc/bitops.h.orig Mon Sep 24 01:27:31 2001
+++ ./linux/include/asm-parisc/bitops.h.mod Mon Sep 24 01:41:38 2001
@@ -50,6 +50,26 @@
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(addr), flags);
}
+/*
+ * Non-Atomic __set_bit
+ *
+ * If called by multiple processes, only one will succeed.
+ * The others would have been reordered before the succeeding
+ * call.
+ *
+ */
+
+static __inline__ void __set_bit(int nr, void * address)
+{
+ unsigned long mask;
+ unsigned long *addr = (unsigned long *) address;
+
+ addr += (nr >> SHIFT_PER_LONG);
+ mask = 1L << CHOP_SHIFTCOUNT(nr);
+ *addr |= mask;
+}
+
+
static __inline__ int test_and_clear_bit(int nr, void * address)
{
unsigned long mask;
@@ -66,6 +86,25 @@
return oldbit;
}
+
+/*
+ * Non-Atomic __test_and_clear_bit
+ *
+ */
+
+static __inline__ int __test_and_clear_bit(int nr, void * address)
+{
+ unsigned long mask;
+ unsigned long *addr = (unsigned long *) address;
+ int oldbit;
+ addr += (nr >> SHIFT_PER_LONG);
+ mask = 1L << CHOP_SHIFTCOUNT(nr);
+ oldbit = (*addr & mask) ? 1 : 0;
+ *addr &= ~mask;
+ return oldbit;
+}
+
+
static __inline__ void clear_bit(int nr, void * address)
{
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