From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-ia64@vger.kernel.org
Subject: [PATCH v3 02/11] ia64: Add clear_bit_unlock_is_negative_byte implementation
Date: Thu, 16 Apr 2020 15:01:21 -0700 [thread overview]
Message-ID: <20200416220130.13343-3-willy@infradead.org> (raw)
In-Reply-To: <20200416220130.13343-1-willy@infradead.org>
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Copy and paste the clear_bit_unlock() implementation, and test the old
variable to see if it has bit 7 set.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
---
arch/ia64/include/asm/bitops.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/ia64/include/asm/bitops.h b/arch/ia64/include/asm/bitops.h
index 2f24ee6459d2..ba92ca44731b 100644
--- a/arch/ia64/include/asm/bitops.h
+++ b/arch/ia64/include/asm/bitops.h
@@ -117,6 +117,26 @@ clear_bit_unlock (int nr, volatile void *addr)
} while (cmpxchg_rel(m, old, new) != old);
}
+static inline bool clear_bit_unlock_is_negative_byte(unsigned int nr,
+ volatile unsigned long *p)
+{
+ __u32 mask, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ mask = ~(1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old & mask;
+ } while (cmpxchg_rel(m, old, new) != old);
+
+ return old & (1 << 7);
+}
+#define clear_bit_unlock_is_negative_byte \
+ clear_bit_unlock_is_negative_byte
+
/**
* __clear_bit_unlock - Non-atomically clears a bit in memory with release
* @nr: Bit to clear
--
2.25.1
next prev parent reply other threads:[~2020-04-16 22:01 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 22:01 [PATCH v3 00/11] Make PageWriteback use the PageLocked optimisation Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 01/11] alpha: Add clear_bit_unlock_is_negative_byte implementation Matthew Wilcox
2020-04-16 22:01 ` Matthew Wilcox [this message]
2020-04-16 22:01 ` [PATCH v3 03/11] m68k: " Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 04/11] mips: " Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 05/11] riscv: " Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 06/11] s390: " Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 07/11] mm: Remove definition of clear_bit_unlock_is_negative_byte Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 08/11] mm: Move PG_writeback into the bottom byte Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 09/11] mm: Convert writeback BUG to WARN_ON Matthew Wilcox
2020-04-23 15:58 ` Jan Kara
2020-04-16 22:01 ` [PATCH v3 10/11] mm: Use clear_bit_unlock_is_negative_byte for PageWriteback Matthew Wilcox
2020-04-16 22:01 ` [PATCH v3 11/11] mm: Remove TestClearPageWriteback Matthew Wilcox
2020-04-17 7:28 ` [PATCH v3 00/11] Make PageWriteback use the PageLocked optimisation Geert Uytterhoeven
2020-04-17 11:12 ` Matthew Wilcox
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