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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: mike.leach@linaro.org
Cc: coresight@lists.linaro.org, anshuman.khandual@arm.com,
	mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org,
	leo.yan@linaro.org
Subject: Re: [PATCH 11/19] coresight: etm4x: Check for OS and Software Lock
Date: Tue, 22 Sep 2020 11:44:00 +0100	[thread overview]
Message-ID: <814857b0-4136-5ba7-cb3d-d51de3890468@arm.com> (raw)
In-Reply-To: <CAJ9a7VjDeWk3uwA+bFpTQtjgf6xeMt43Z_Q2Yw1D4atLgcRhcA@mail.gmail.com>

On 09/18/2020 04:35 PM, Mike Leach wrote:
> Hi Suzuki
> 
> On Fri, 11 Sep 2020 at 09:41, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>>
>> An ETM instance may not implement the OS/Software Lock. This
>> is advertised via TRCOSLSR/TRCLSR respectively. Detect the
>> presence of these lock registers and skip the lock/unlock
>> if they are not implemented.
>>
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-etm4x.c | 77 +++++++++++++++----
>>   drivers/hwtracing/coresight/coresight-etm4x.h | 24 +++++-
>>   2 files changed, 83 insertions(+), 18 deletions(-)
>>


>>
>> +/*
>> + * ETM may or may not implement the Software Lock and the OS Lock.
>> + * Detect this before we attempt to do any locking.
>> + */
>> +static void etm_detect_lock_status(struct etmv4_drvdata *drvdata,
>> +                                  struct csdev_access *csa)
>> +{
>> +       u32 sw_lsr = etm4x_relaxed_read32(csa, TRCLSR);
> 
> 7.3.48 - ETMv4.5 spec -> TRCLSR accessible only from the memory mapped
> interface.
> 

Good point, I have fixed this now.

>> +       u32 os_lsr = etm4x_relaxed_read32(csa, TRCOSLSR);
> 
> This is unneeded. 7.3.50 of the ETM4.5 spec says for OS lock bits
> "always 0b10 for Armv8-A/R, Armv7-A/R,". So always implemented.

Agreed, I will drop this for now.

Cheers
Suzuki

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  reply	other threads:[~2020-09-22 10:40 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11  8:41 [PATCH 00/19] coresight: Support for ETMv4.4 system instructions Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 01/19] coresight: Introduce device access abstraction Suzuki K Poulose
2020-09-18 15:33   ` Mike Leach
2020-09-11  8:41 ` [PATCH 02/19] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 03/19] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 04/19] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 05/19] coresight: Use device access layer for Software lock/unlock operations Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-18 15:52     ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 06/19] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 07/19] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 08/19] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 09/19] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-11  8:41 ` [PATCH 10/19] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2020-09-18 15:34   ` Mike Leach
2020-09-22 10:20     ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 11/19] coresight: etm4x: Check for OS and Software Lock Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-22 10:44     ` Suzuki K Poulose [this message]
2020-09-11  8:41 ` [PATCH 12/19] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-22 10:55     ` Suzuki K Poulose
2020-09-22 12:47       ` Mike Leach
2020-09-30 10:32         ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 13/19] coresight: etm4x: Clean up " Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-22 10:59     ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 14/19] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 15/19] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-22 11:18     ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 16/19] coresight: etm4x: Detect system instructions support Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-22 11:59     ` Suzuki K Poulose
2020-09-11  8:41 ` [PATCH 17/19] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-11  8:41 ` [PATCH 18/19] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-23 11:52     ` Suzuki K Poulose
2020-09-23 16:55       ` Mike Leach
2020-09-11  8:41 ` [PATCH 19/19] dts: bindings: coresight: ETMv4.4 system register access only units Suzuki K Poulose
2020-09-18 15:35   ` Mike Leach
2020-09-24  9:48     ` Suzuki K Poulose
2020-09-24 10:08       ` Mike Leach
2020-09-18 15:33 ` [PATCH 00/19] coresight: Support for ETMv4.4 system instructions Mike Leach
2020-09-25  9:55   ` Suzuki K Poulose
2020-09-29 16:42     ` Mike Leach

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