Thread (7 messages) 7 messages, 3 authors, 2018-02-01

Re: [PATCH 1/2] MIPS: Watch: Avoid duplication of bits in mips_install_watch_registers.

From: James Hogan <jhogan@kernel.org>
Date: 2018-02-01 16:07:07
Also in: lkml

On Tue, Jan 02, 2018 at 11:31:21AM +0000, Matt Redfearn wrote:
Currently the bits to be set in the watchhi register in addition to that
requested by the user is defined inline for each register. To avoid
this, define the bits once and or that in for each register.

Signed-off-by: Matt Redfearn <redacted>
Both patches applied to my 4.16 branch,

Thanks
James
quoted hunk ↗ jump to hunk
---

 arch/mips/kernel/watch.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/arch/mips/kernel/watch.c b/arch/mips/kernel/watch.c
index 19fcab7348b1..329d2209521d 100644
--- a/arch/mips/kernel/watch.c
+++ b/arch/mips/kernel/watch.c
@@ -18,27 +18,24 @@
 void mips_install_watch_registers(struct task_struct *t)
 {
 	struct mips3264_watch_reg_state *watches = &t->thread.watch.mips3264;
+	unsigned int watchhi = MIPS_WATCHHI_G |		/* Trap all ASIDs */
+			       MIPS_WATCHHI_IRW;	/* Clear result bits */
+
 	switch (current_cpu_data.watch_reg_use_cnt) {
 	default:
 		BUG();
 	case 4:
 		write_c0_watchlo3(watches->watchlo[3]);
-		/* Write 1 to the I, R, and W bits to clear them, and
-		   1 to G so all ASIDs are trapped. */
-		write_c0_watchhi3(MIPS_WATCHHI_G | MIPS_WATCHHI_IRW |
-				  watches->watchhi[3]);
+		write_c0_watchhi3(watchhi | watches->watchhi[3]);
 	case 3:
 		write_c0_watchlo2(watches->watchlo[2]);
-		write_c0_watchhi2(MIPS_WATCHHI_G | MIPS_WATCHHI_IRW |
-				  watches->watchhi[2]);
+		write_c0_watchhi2(watchhi | watches->watchhi[2]);
 	case 2:
 		write_c0_watchlo1(watches->watchlo[1]);
-		write_c0_watchhi1(MIPS_WATCHHI_G | MIPS_WATCHHI_IRW |
-				  watches->watchhi[1]);
+		write_c0_watchhi1(watchhi | watches->watchhi[1]);
 	case 1:
 		write_c0_watchlo0(watches->watchlo[0]);
-		write_c0_watchhi0(MIPS_WATCHHI_G | MIPS_WATCHHI_IRW |
-				  watches->watchhi[0]);
+		write_c0_watchhi0(watchhi | watches->watchhi[0]);
 	}
 }
 
-- 
2.7.4

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