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

From: James Hogan
Date: Thu Feb 01 2018 - 11:07:09 EST


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 <matt.redfearn@xxxxxxxx>

Both patches applied to my 4.16 branch,

Thanks
James

> ---
>
> 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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