From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv2 04/11] arm: arch_timer: standardise counter reading
Date: Tue, 15 Jan 2013 16:08:18 +0530 [thread overview]
Message-ID: <50F5319A.7060905@ti.com> (raw)
In-Reply-To: <20130115102519.GG7990@e106331-lin.cambridge.arm.com>
On Tuesday 15 January 2013 03:55 PM, Mark Rutland wrote:
> On Fri, Jan 11, 2013 at 01:23:33PM +0000, Santosh Shilimkar wrote:
>> On Wednesday 09 January 2013 09:37 PM, Mark Rutland wrote:
>>> We're currently inconsistent with respect to our accesses to the
>>> physical and virtual counters, mixing and matching the two.
>>>
>>> This patch introduces and uses a function for accessing the correct
>>> counter based on whether we're using physical or virtual interrupts.
>>> All current accesses to the counter accessors are redirected through
>>> it.
>>>
>>> Signed-off-by: Mark Rutland <mark.rutland@arm•com>
>>> Acked-by: Catalin Marinas <catalin.marinas@arm•com>
>>> Acked-by: Marc Zyngier <marc.zyngier@arm•com>
>>> ---
>>> arch/arm/kernel/arch_timer.c | 48 ++++++++++-------------------------------
>>> 1 files changed, 12 insertions(+), 36 deletions(-)
>>>
>>> diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
>>> index 498c29f..0d2681c 100644
>>> --- a/arch/arm/kernel/arch_timer.c
>>> +++ b/arch/arm/kernel/arch_timer.c
>>> @@ -272,51 +272,32 @@ static int arch_timer_available(void)
>>> return 0;
>>> }
>>>
>>> -static u32 notrace arch_counter_get_cntpct32(void)
>>> +u64 arch_timer_read_counter(void)
>>> {
>>> - cycle_t cnt = arch_counter_get_cntpct();
>>> -
>>> - /*
>>> - * The sched_clock infrastructure only knows about counters
>>> - * with at most 32bits. Forget about the upper 24 bits for the
>>> - * time being...
>>> - */
>>> - return (u32)cnt;
>>> + if (arch_timer_use_virtual)
>>> + return arch_counter_get_cntvct();
>>> + else
>>> + return arch_counter_get_cntpct();
>>> }
>>>
>>
>> [...]
>>
>>> @@ -489,18 +470,13 @@ int __init arch_timer_of_register(void)
>>>
>>> int __init arch_timer_sched_clock_init(void)
>>> {
>>> - u32 (*cnt32)(void);
>>> int err;
>>>
>>> err = arch_timer_available();
>>> if (err)
>>> return err;
>>>
>>> - if (arch_timer_use_virtual)
>>> - cnt32 = arch_counter_get_cntvct32;
>>> - else
>>> - cnt32 = arch_counter_get_cntpct32;
>>> -
>>> - setup_sched_clock(cnt32, 32, arch_timer_rate);
>>> + setup_sched_clock(arch_timer_read_counter32,
>>> + 32, arch_timer_rate);
>>> return 0;
>>> }
>>>
>> I think the original idea had merit since the check was needed
>> in init code instead of proposed one which has if check for
>> every counter read function. No ?
>>
>
> The original idea was good in that it avoided the check on each read path, but
> in several places the logic got duplicated (e.g. for choosing which
> width-altering wrapper in the above block). I'd like ensure this logic is
> consolidated.
>
> I'll change arch_timer_read_counter to a function pointer, and set this in
> arch_timer_of_register before registering anything. Everything would still be
> indirected through it, but it won't have to do a check on every read.
>
Sounds good
next prev parent reply other threads:[~2013-01-15 10:38 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-09 16:07 [PATCHv3 00/11] Unify arm_generic and arch_timer drivers Mark Rutland
2013-01-09 16:07 ` [PATCHv2 01/11] arm: arch_timer: balance device_node refcounting Mark Rutland
2013-01-11 12:59 ` Santosh Shilimkar
2013-01-09 16:07 ` [PATCHv2 02/11] arm: arch_timer: remove redundant available check Mark Rutland
2013-01-11 13:11 ` Santosh Shilimkar
2013-01-11 14:07 ` Mark Rutland
2013-01-09 16:07 ` [PATCHv2 03/11] arm: arch_timer: use u64/u32 for register data Mark Rutland
2013-01-11 13:19 ` Santosh Shilimkar
2013-01-09 16:07 ` [PATCHv2 04/11] arm: arch_timer: standardise counter reading Mark Rutland
2013-01-11 13:23 ` Santosh Shilimkar
2013-01-15 10:25 ` Mark Rutland
2013-01-15 10:38 ` Santosh Shilimkar [this message]
2013-01-09 16:07 ` [PATCHv2 05/11] arm: arch_timer: split cntfrq accessor Mark Rutland
2013-01-11 13:27 ` Santosh Shilimkar
2013-01-11 14:16 ` Mark Rutland
2013-01-09 16:07 ` [PATCHv2 06/11] arm: arch_timer: factor out register accessors Mark Rutland
2013-01-11 13:32 ` Santosh Shilimkar
2013-01-11 14:31 ` Mark Rutland
2013-01-09 16:07 ` [PATCHv2 07/11] arm: arch_timer: divorce from local_timer api Mark Rutland
2013-01-11 13:34 ` Santosh Shilimkar
2013-01-11 16:46 ` Catalin Marinas
2013-01-11 16:56 ` Santosh Shilimkar
2013-01-09 16:07 ` [PATCHv2 08/11] arm: arch_timer: add arch_counter_set_user_access Mark Rutland
2013-01-11 13:40 ` Santosh Shilimkar
2013-01-11 14:54 ` Mark Rutland
2013-01-11 15:07 ` Will Deacon
2013-01-11 17:00 ` Santosh Shilimkar
2013-01-11 16:50 ` Catalin Marinas
2013-01-11 16:57 ` Santosh Shilimkar
2013-01-11 17:54 ` Mark Rutland
2013-01-09 16:07 ` [PATCHv2 09/11] arm: arch_timer: move core to drivers/clocksource Mark Rutland
2013-01-11 13:48 ` Santosh Shilimkar
2013-01-11 15:04 ` Mark Rutland
2013-01-09 16:07 ` [PATCHv2 10/11] arm64: move from arm_generic to arm_arch_timer Mark Rutland
2013-01-11 13:50 ` Santosh Shilimkar
2013-01-09 16:07 ` [PATCHv2 11/11] Documentation: Add ARMv8 to arch_timer devicetree Mark Rutland
2013-01-11 13:52 ` Santosh Shilimkar
-- strict thread matches above, loose matches on Subject: below --
2012-12-19 15:10 [PATCHv2 00/11] Unify arm_generic and arch_timer drivers Mark Rutland
2012-12-19 15:11 ` [PATCHv2 04/11] arm: arch_timer: standardise counter reading Mark Rutland
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=50F5319A.7060905@ti.com \
--to=santosh.shilimkar@ti$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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