The patch titled
mips: lock bitops
has been removed from the -mm tree. Its filename was
mips-lock-bitops.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: mips: lock bitops
From: Nick Piggin <npiggin@xxxxxxx>
mips can avoid one mb when acquiring a lock with test_and_set_bit_lock.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-mips/bitops.h | 97 +++++++++++++++++++++++++++++++++++-
1 file changed, 96 insertions(+), 1 deletion(-)
diff -puN include/asm-mips/bitops.h~mips-lock-bitops include/asm-mips/bitops.h
--- a/include/asm-mips/bitops.h~mips-lock-bitops
+++ a/include/asm-mips/bitops.h
@@ -172,6 +172,20 @@ static inline void clear_bit(unsigned lo
}
/*
+ * clear_bit_unlock - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * clear_bit() is atomic and implies release semantics before the memory
+ * operation. It can be used for an unlock.
+ */
+static inline void clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
+{
+ smp_mb__before_clear_bit();
+ clear_bit(nr, addr);
+}
+
+/*
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
@@ -297,6 +311,73 @@ static inline int test_and_set_bit(unsig
}
/*
+ * test_and_set_bit_lock - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and implies acquire ordering semantics
+ * after the memory operation.
+ */
+static inline int test_and_set_bit_lock(unsigned long nr,
+ volatile unsigned long *addr)
+{
+ unsigned short bit = nr & SZLONG_MASK;
+ unsigned long res;
+
+ if (cpu_has_llsc && R10000_LLSC_WAR) {
+ unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
+ unsigned long temp;
+
+ __asm__ __volatile__(
+ " .set mips3 \n"
+ "1: " __LL "%0, %1 # test_and_set_bit \n"
+ " or %2, %0, %3 \n"
+ " " __SC "%2, %1 \n"
+ " beqzl %2, 1b \n"
+ " and %2, %0, %3 \n"
+ " .set mips0 \n"
+ : "=&r" (temp), "=m" (*m), "=&r" (res)
+ : "r" (1UL << bit), "m" (*m)
+ : "memory");
+ } else if (cpu_has_llsc) {
+ unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
+ unsigned long temp;
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noreorder \n"
+ " .set mips3 \n"
+ "1: " __LL "%0, %1 # test_and_set_bit \n"
+ " or %2, %0, %3 \n"
+ " " __SC "%2, %1 \n"
+ " beqz %2, 2f \n"
+ " and %2, %0, %3 \n"
+ " .subsection 2 \n"
+ "2: b 1b \n"
+ " nop \n"
+ " .previous \n"
+ " .set pop \n"
+ : "=&r" (temp), "=m" (*m), "=&r" (res)
+ : "r" (1UL << bit), "m" (*m)
+ : "memory");
+ } else {
+ volatile unsigned long *a = addr;
+ unsigned long mask;
+ unsigned long flags;
+
+ a += nr >> SZLONG_LOG;
+ mask = 1UL << bit;
+ raw_local_irq_save(flags);
+ res = (mask & *a);
+ *a |= mask;
+ raw_local_irq_restore(flags);
+ }
+
+ smp_llsc_mb();
+
+ return res != 0;
+}
+/*
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
@@ -459,6 +540,21 @@ static inline int test_and_change_bit(un
#include <asm-generic/bitops/non-atomic.h>
/*
+ * __clear_bit_unlock - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * __clear_bit() is non-atomic and implies release semantics before the memory
+ * operation. It can be used for an unlock if no other CPUs can concurrently
+ * modify other bits in the word.
+ */
+static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
+{
+ smp_mb();
+ __clear_bit(nr, addr);
+}
+
+/*
* Return the bit position (0..63) of the most significant 1 bit in a word
* Returns -1 if no 1 bit exists
*/
@@ -562,7 +658,6 @@ static inline int ffs(int word)
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
-#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/ext2-non-atomic.h>
#include <asm-generic/bitops/ext2-atomic.h>
#include <asm-generic/bitops/minix.h>
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
origin.patch
fs-introduce-write_begin-write_end-and-perform_write-aops-revoke.patch
fs-introduce-write_begin-write_end-and-perform_write-aops-revoke-fix.patch
reiser4-fix-for-new-aops-patches.patch
-
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