public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH V7 2/6] arm64/perf: Add BRBE registers and fields
Date: Fri, 13 Jan 2023 08:32:47 +0530	[thread overview]
Message-ID: <16dcb986-74df-9a78-5cfc-e9f59fbe0997@arm.com> (raw)
In-Reply-To: <Y8AKAZMq7YzOpwwV@FVFF77S0Q05N>

On 1/12/23 18:54, Mark Rutland wrote:
> Hi Anshuman,
> 
> On Thu, Jan 05, 2023 at 08:40:35AM +0530, Anshuman Khandual wrote:
>> This adds BRBE related register definitions and various other related field
>> macros there in. These will be used subsequently in a BRBE driver which is
>> being added later on.
> 
> I haven't verified the specific values, but this looks good to me aside from
> one minor nit below.
> 
> [...]
> 
>> +# This is just a dummy register declaration to get all common field masks and
>> +# shifts for accessing given BRBINF contents.
>> +Sysreg	BRBINF_EL1	2	1	8	0	0
> 
> We don't need a dummy declaration, as we have 'SysregFields' that can be used
> for this, e.g.
> 
>   SysregFields BRBINFx_EL1
>   ...
>   EndSysregFields
> 
> ... which will avoid accidental usage of the register encoding. Note that I've
> also added an 'x' there in place of the index, which we do for other registers,
> e.g. TTBRx_EL1.
> 
> Could you please update to that?

There is a problem in defining SysregFields (which I did explore earlier as well).
SysregFields unfortunately does not support enums fields. Following build failure
comes up, while trying to convert BRBINFx_EL1 into a SysregFields definition.

Error at 932: unexpected Enum (inside SysregFields)

===============================================================================
diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index a7f9054bd84c..519c4f080898 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -921,10 +921,7 @@ Enum       3:0     BT
 EndEnum
 EndSysreg
 
-
-# This is just a dummy register declaration to get all common field masks and
-# shifts for accessing given BRBINF contents.
-Sysreg BRBINF_EL1      2       1       8       0       0
+SysregFields BRBINFx_EL1
 Res0   63:47
 Field  46      CCU
 Field  45:32   CC
@@ -967,7 +964,7 @@ Enum        1:0     VALID
        0b10    SOURCE
        0b11    FULL
 EndEnum
-EndSysreg
+EndSysregFields
 
 Sysreg BRBCR_EL1       2       1       9       0       0
 Res0   63:24
===============================================================================

There are three enum fields in BRBINFx_EL1 as listed here.

Enum    13:8            TYPE
Enum    7:6		EL
Enum    1:0     	VALID

However, BRBINF_EL1 can be changed as BRBINFx_EL1, indicating its more generic
nature with a potential to be used for any index value register thereafter.

> 
> With that:
> 
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> 
> Mark.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2023-01-13  3:04 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-05  3:10 [PATCH V7 0/6] arm64/perf: Enable branch stack sampling Anshuman Khandual
2023-01-05  3:10 ` [PATCH V7 1/6] drivers: perf: arm_pmu: Add new sched_task() callback Anshuman Khandual
2023-01-05  3:10 ` [PATCH V7 2/6] arm64/perf: Add BRBE registers and fields Anshuman Khandual
2023-01-12 13:24   ` Mark Rutland
2023-01-13  3:02     ` Anshuman Khandual [this message]
2023-02-08 19:22       ` Mark Rutland
2023-02-09  5:49         ` Anshuman Khandual
2023-02-09 10:08           ` Mark Rutland
2023-01-05  3:10 ` [PATCH V7 3/6] arm64/perf: Add branch stack support in struct arm_pmu Anshuman Khandual
2023-01-12 13:54   ` Mark Rutland
2023-01-13  4:15     ` Anshuman Khandual
2023-02-08 19:26       ` Mark Rutland
2023-02-09  3:40         ` Anshuman Khandual
2023-01-05  3:10 ` [PATCH V7 4/6] arm64/perf: Add branch stack support in struct pmu_hw_events Anshuman Khandual
2023-01-12 13:59   ` Mark Rutland
2023-01-05  3:10 ` [PATCH V7 5/6] arm64/perf: Add branch stack support in ARMV8 PMU Anshuman Khandual
2023-01-12 14:29   ` Mark Rutland
2023-01-13  5:11     ` Anshuman Khandual
2023-02-08 19:36       ` Mark Rutland
2023-02-13  8:23         ` Anshuman Khandual
2023-02-23 13:47           ` Mark Rutland
2023-03-06  7:59             ` Anshuman Khandual
2023-01-05  3:10 ` [PATCH V7 6/6] arm64/perf: Enable branch stack events via FEAT_BRBE Anshuman Khandual
2023-01-12 16:51   ` Mark Rutland
2023-01-19  2:48     ` Anshuman Khandual
2023-02-08 20:03       ` Mark Rutland
2023-02-20  8:38         ` Anshuman Khandual
2023-02-23 13:38           ` Mark Rutland
2023-01-06 10:23 ` [PATCH V7 0/6] arm64/perf: Enable branch stack sampling James Clark
2023-01-06 11:13   ` Anshuman Khandual
2023-01-11  5:05 ` Anshuman Khandual

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=16dcb986-74df-9a78-5cfc-e9f59fbe0997@arm.com \
    --to=anshuman.khandual@arm.com \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=maz@kernel.org \
    --cc=will@kernel.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