From: Mark Rutland <mark.rutland@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>,
Wim Van Sebroeck <wim@linux-watchdog.org>,
Valentin Schneider <valentin.schneider@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 5/7] clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable
Date: Mon, 8 Apr 2019 17:04:34 +0100 [thread overview]
Message-ID: <20190408160433.GQ6139@lakrids.cambridge.arm.com> (raw)
In-Reply-To: <20190408154907.223536-6-marc.zyngier@arm.com>
On Mon, Apr 08, 2019 at 04:49:05PM +0100, Marc Zyngier wrote:
> Let's start with the removal of the arch_timer_read_ool_enabled
> static key in arch_timer_reg_read_stable. IT is not a fast path,
Nit: s/IT/It/
> and we can simplify things a bit.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/include/asm/arch_timer.h | 42 +++++++++++++++++++----------
> 1 file changed, 28 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
> index c3762ffcc933..4a06d46def7e 100644
> --- a/arch/arm64/include/asm/arch_timer.h
> +++ b/arch/arm64/include/asm/arch_timer.h
> @@ -77,23 +77,37 @@ struct arch_timer_erratum_workaround {
> DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *,
> timer_unstable_counter_workaround);
>
> +/* inline sysreg accessors that make erratum_handler() work */
> +static inline notrace u32 arch_timer_read_cntp_tval_el0(void)
> +{
> + return read_sysreg(cntp_tval_el0);
> +}
> +
> +static inline notrace u32 arch_timer_read_cntv_tval_el0(void)
> +{
> + return read_sysreg(cntv_tval_el0);
> +}
> +
> +static inline notrace u64 arch_timer_read_cntpct_el0(void)
> +{
> + return read_sysreg(cntpct_el0);
> +}
> +
> +static inline notrace u64 arch_timer_read_cntvct_el0(void)
> +{
> + return read_sysreg(cntvct_el0);
> +}
> +
> #define arch_timer_reg_read_stable(reg) \
> -({ \
> - u64 _val; \
> - if (needs_unstable_timer_counter_workaround()) { \
> - const struct arch_timer_erratum_workaround *wa; \
> + ({ \
> + u64 _val; \
> + \
> preempt_disable_notrace(); \
> - wa = __this_cpu_read(timer_unstable_counter_workaround); \
> - if (wa && wa->read_##reg) \
> - _val = wa->read_##reg(); \
> - else \
> - _val = read_sysreg(reg); \
> + _val = erratum_handler(read_ ## reg)(); \
> preempt_enable_notrace(); \
> - } else { \
> - _val = read_sysreg(reg); \
> - } \
> - _val; \
> -})
> + \
> + _val; \
> + })
>
> /*
> * These register accessors are marked inline so the compiler can
> --
> 2.20.1
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-08 16:04 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-08 15:49 [PATCH 0/7] clocksource/arm_arch_timer: Removing the static branch on errata handling Marc Zyngier
2019-04-08 15:49 ` [PATCH 1/7] ARM: vdso: Remove dependency with the arch_timer driver internals Marc Zyngier
2019-04-08 15:58 ` Mark Rutland
2019-04-15 10:46 ` Marc Zyngier
2019-04-30 14:23 ` Will Deacon
2019-04-08 15:49 ` [PATCH 2/7] watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct Marc Zyngier
2019-04-08 15:59 ` Mark Rutland
2019-04-08 18:07 ` Guenter Roeck
2019-04-09 7:43 ` Marc Zyngier
2019-04-08 15:49 ` [PATCH 3/7] arm64: " Marc Zyngier
2019-04-08 15:59 ` Mark Rutland
2019-04-08 15:49 ` [PATCH 4/7] clocksource/arm_arch_timer: Direcly assign set_next_event workaround Marc Zyngier
2019-04-08 16:02 ` Mark Rutland
2019-04-11 17:17 ` Daniel Lezcano
2019-04-15 10:18 ` Marc Zyngier
2019-04-08 15:49 ` [PATCH 5/7] clocksource/arm_arch_timer: Drop use of static key in arch_timer_reg_read_stable Marc Zyngier
2019-04-08 16:04 ` Mark Rutland [this message]
2019-04-15 11:04 ` Daniel Lezcano
2019-04-08 15:49 ` [PATCH 6/7] clocksource/arm_arch_timer: Remove use of workaround static key Marc Zyngier
2019-04-08 16:05 ` Mark Rutland
2019-04-15 11:07 ` Daniel Lezcano
2019-04-08 15:49 ` [PATCH 7/7] clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters Marc Zyngier
2019-04-08 16:08 ` Mark Rutland
2019-04-15 12:16 ` Daniel Lezcano
2019-04-30 15:27 ` Marc Zyngier
2019-04-30 15:39 ` Valentin Schneider
2019-05-03 20:32 ` Daniel Lezcano
2019-05-03 20:31 ` Daniel Lezcano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190408160433.GQ6139@lakrids.cambridge.arm.com \
--to=mark.rutland@arm.com \
--cc=catalin.marinas@arm.com \
--cc=daniel.lezcano@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=linux@roeck-us.net \
--cc=marc.zyngier@arm.com \
--cc=valentin.schneider@arm.com \
--cc=will.deacon@arm.com \
--cc=wim@linux-watchdog.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).