linux-kernel - Re: [PATCH] soc: qcom: Rework BCM_TCS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6852b25f-94a4-4e04-adc5-5c79eb1f17ca@oss.qualcomm.com>
Date: Fri, 25 Oct 2024 19:03:01 +0200
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Eugen Hristev <eugen.hristev@...aro.org>,
        Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: andersson@...nel.org, konradybcio@...nel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH] soc: qcom: Rework BCM_TCS_CMD macro

On 25.10.2024 2:06 PM, Eugen Hristev wrote:
> 
> 
> On 10/25/24 12:03, Konrad Dybcio wrote:
>> On 25.10.2024 10:48 AM, Eugen Hristev wrote:
>>> Reworked BCM_TCS_CMD macro in order to fix warnings from sparse:
>>>
>>> drivers/clk/qcom/clk-rpmh.c:270:28: warning: restricted __le32 degrades to integer
>>> drivers/clk/qcom/clk-rpmh.c:270:28: warning: restricted __le32 degrades to integer
>>>
>>> While at it, used u32_encode_bits which made the code easier to
>>> follow and removed unnecessary shift definitions.
>>>
>>> Signed-off-by: Eugen Hristev <eugen.hristev@...aro.org>
>>> ---
>>>   include/soc/qcom/tcs.h | 19 ++++++++-----------
>>>   1 file changed, 8 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/include/soc/qcom/tcs.h b/include/soc/qcom/tcs.h
>>> index 3acca067c72b..130ed2582f37 100644
>>> --- a/include/soc/qcom/tcs.h
>>> +++ b/include/soc/qcom/tcs.h
>>> @@ -60,22 +60,19 @@ struct tcs_request {
>>>       struct tcs_cmd *cmds;
>>>   };
>>>   -#define BCM_TCS_CMD_COMMIT_SHFT        30
>>>   #define BCM_TCS_CMD_COMMIT_MASK        0x40000000
>>> -#define BCM_TCS_CMD_VALID_SHFT        29
>>>   #define BCM_TCS_CMD_VALID_MASK        0x20000000
>>> -#define BCM_TCS_CMD_VOTE_X_SHFT        14
>>>   #define BCM_TCS_CMD_VOTE_MASK        0x3fff
>>> -#define BCM_TCS_CMD_VOTE_Y_SHFT        0
>>> -#define BCM_TCS_CMD_VOTE_Y_MASK        0xfffc000
>>> +#define BCM_TCS_CMD_VOTE_Y_MASK        0x3fff
>>> +#define BCM_TCS_CMD_VOTE_X_MASK        0xfffc000
>>>     /* Construct a Bus Clock Manager (BCM) specific TCS command */
>>>   #define BCM_TCS_CMD(commit, valid, vote_x, vote_y)        \
>>> -    (((commit) << BCM_TCS_CMD_COMMIT_SHFT) |        \
>>> -    ((valid) << BCM_TCS_CMD_VALID_SHFT) |            \
>>> -    ((cpu_to_le32(vote_x) &                    \
>>> -    BCM_TCS_CMD_VOTE_MASK) << BCM_TCS_CMD_VOTE_X_SHFT) |    \
>>> -    ((cpu_to_le32(vote_y) &                    \
>>> -    BCM_TCS_CMD_VOTE_MASK) << BCM_TCS_CMD_VOTE_Y_SHFT))
>>> +    (u32_encode_bits(commit, BCM_TCS_CMD_COMMIT_MASK) |    \
>>> +    u32_encode_bits(valid, BCM_TCS_CMD_VALID_MASK) |    \
>>> +    u32_encode_bits((__force u32)cpu_to_le32(vote_x),    \
>>> +            BCM_TCS_CMD_VOTE_X_MASK) |        \
>>> +    u32_encode_bits((__force u32)cpu_to_le32(vote_y),    \
>>> +            BCM_TCS_CMD_VOTE_Y_MASK))
>>
>> FIELD_PREP/GET?
>>
>> Konrad
> 
> What would be the difference/advantage in using FIELD_PREP/GET instead of u32_encode_bits ?

Probably none. I thought it was a function and not another magic macro,
as it's lowercase..

Doesn't le32_encode_bits do what you need then?

Konrad