linux-kernel - [PATCH 2/2] MIPS: Watch: Avoid duplication of bits in mips_read_watch

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Date:   Tue, 2 Jan 2018 11:31:22 +0000
From:   Matt Redfearn <matt.redfearn@...s.com>
To:     <ralf@...ux-mips.org>
CC:     <linux-mips@...ux-mips.org>, <linux-kernel@...r.kernel.org>,
        Matt Redfearn <matt.redfearn@...s.com>
Subject: [PATCH 2/2] MIPS: Watch: Avoid duplication of bits in mips_read_watch_registers

Currently the bits to be masked when watchhi is read is defined inline
for each register. To avoid this, define the bits once and mask each
register with that value.

Signed-off-by: Matt Redfearn <matt.redfearn@...s.com>
---

 arch/mips/kernel/watch.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/mips/kernel/watch.c b/arch/mips/kernel/watch.c
index 329d2209521d..0e61a5b7647f 100644
--- a/arch/mips/kernel/watch.c
+++ b/arch/mips/kernel/watch.c
@@ -48,21 +48,19 @@ void mips_read_watch_registers(void)
 {
 	struct mips3264_watch_reg_state *watches =
 		&current->thread.watch.mips3264;
+	unsigned int watchhi_mask = MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW;
+
 	switch (current_cpu_data.watch_reg_use_cnt) {
 	default:
 		BUG();
 	case 4:
-		watches->watchhi[3] = (read_c0_watchhi3() &
-				       (MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW));
+		watches->watchhi[3] = (read_c0_watchhi3() & watchhi_mask);
 	case 3:
-		watches->watchhi[2] = (read_c0_watchhi2() &
-				       (MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW));
+		watches->watchhi[2] = (read_c0_watchhi2() & watchhi_mask);
 	case 2:
-		watches->watchhi[1] = (read_c0_watchhi1() &
-				       (MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW));
+		watches->watchhi[1] = (read_c0_watchhi1() & watchhi_mask);
 	case 1:
-		watches->watchhi[0] = (read_c0_watchhi0() &
-				       (MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW));
+		watches->watchhi[0] = (read_c0_watchhi0() & watchhi_mask);
 	}
 	if (current_cpu_data.watch_reg_use_cnt == 1 &&
 	    (watches->watchhi[0] & MIPS_WATCHHI_IRW) == 0) {
-- 
2.7.4