From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv5 07/16] arm: arch_timer: add isbs to register accessors
Date: Thu, 31 Jan 2013 15:35:45 +0000 [thread overview]
Message-ID: <20130131153545.GI12877@arm.com> (raw)
In-Reply-To: <1359634539-9580-8-git-send-email-mark.rutland@arm.com>
On Thu, Jan 31, 2013 at 12:15:30PM +0000, Mark Rutland wrote:
> Without the isbs in arch_timer_get_cnt{p,v}ct the cpu may speculate
> reads and return stale values. This could be bad for code sensitive to
> changes in expected deltas between calls (e.g. the delay loop).
>
> Without isbs in arch_timer_reg_write the processor may reorder
> instructions around enabling/disabling of the timer or writing the
> compare value, which we probably don't want.
>
> This patch adds isbs to prevent those issues.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
next prev parent reply other threads:[~2013-01-31 15:35 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-31 12:15 [PATCHv5 00/16] Unify arm_generic and arch_timer drivers Mark Rutland
2013-01-31 12:15 ` [PATCHv5 01/16] arm: arch_timer: balance device_node refcounting Mark Rutland
2013-01-31 15:33 ` Catalin Marinas
2013-01-31 12:15 ` [PATCHv5 02/16] arm: arch_timer: remove redundant available check Mark Rutland
2013-01-31 12:15 ` [PATCHv5 03/16] arm: arch_timer: use u64/u32 for register data Mark Rutland
2013-01-31 12:15 ` [PATCHv5 04/16] arm: arch_timer: standardise counter reading Mark Rutland
2013-01-31 15:34 ` Catalin Marinas
2013-01-31 12:15 ` [PATCHv5 05/16] arm: arch_timer: split cntfrq accessor Mark Rutland
2013-01-31 12:15 ` [PATCHv5 06/16] arm: arch_timer: factor out register accessors Mark Rutland
2013-01-31 12:15 ` [PATCHv5 07/16] arm: arch_timer: add isbs to " Mark Rutland
2013-01-31 15:35 ` Catalin Marinas [this message]
2013-01-31 12:15 ` [PATCHv5 08/16] arm: arch_timer: divorce from local_timer api Mark Rutland
2013-01-31 12:15 ` [PATCHv5 09/16] arm: arch_timer: add arch_counter_set_user_access Mark Rutland
2013-01-31 15:36 ` Catalin Marinas
2013-01-31 12:15 ` [PATCHv5 10/16] arm: arch_timer: move core to drivers/clocksource Mark Rutland
2013-01-31 12:15 ` [PATCHv5 11/16] arm64: arm_generic: prevent reading stale time Mark Rutland
2013-01-31 15:36 ` Catalin Marinas
2013-01-31 12:15 ` [PATCHv5 12/16] arm64: move from arm_generic to arm_arch_timer Mark Rutland
2013-01-31 12:15 ` [PATCHv5 13/16] Documentation: Add ARMv8 to arch_timer devicetree Mark Rutland
2013-01-31 12:15 ` [PATCHv5 14/16] ARM: arch_timers: switch to physical timers if HYP mode is available Mark Rutland
2013-01-31 15:37 ` Catalin Marinas
2013-01-31 12:15 ` [PATCHv5 15/16] ARM: hyp: initialize CNTVOFF to zero Mark Rutland
2013-02-01 11:13 ` Dave Martin
2013-02-01 11:43 ` Marc Zyngier
2013-02-01 11:46 ` Mark Rutland
2013-02-01 18:07 ` Dave Martin
2013-02-04 9:29 ` Mark Rutland
2013-01-31 12:15 ` [PATCHv5 16/16] clocksource: arch_timer: use virtual counters Mark Rutland
2013-01-31 15:38 ` Catalin Marinas
2013-01-31 17:39 ` [PATCHv5 00/16] Unify arm_generic and arch_timer drivers Stephen Warren
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