From: Wenhu Wang <wenhu.wang@hotmail.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
Greg KH <gregkh@linuxfoundation.org>
Cc: "mpe@ellerman.id.au" <mpe@ellerman.id.au>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] uio:powerpc:mpc85xx: l2-cache-sram uio driver implementation
Date: Tue, 14 Jun 2022 07:53:46 +0000 [thread overview]
Message-ID: <SG2PR01MB29516D3BB7525390ADD5B0829FAA9@SG2PR01MB2951.apcprd01.prod.exchangelabs.com> (raw)
In-Reply-To: <c76598b5-2d60-ea22-d590-4cc6998a8830@csgroup.eu>
>> >> +
>> >> +struct mpc85xx_l2ctlr {
>> >> + u32 ctl; /* 0x000 - L2 control */
>> >
>> >What is the endian of these u32 values? You map them directly to
>> >memory, so they must be specified some way, right? Please make it
>> >obvious what they are.
>> >
>>
>> Surely, the values should be u32 here, modified in v2
>> The controller info could be found in
>> "QorIQ™ P2020 Integrated Processor Reference Manual"
>> "Chapter 6 L2 Look-Aside Cache/SRAM"
>> See: http://m4udit.dinauz.org/P2020RM_rev0.pdf
>
>That's not the answer to my question :)
>
>These are big-endian, right? Please mark them as such and access them
>properly with the correct functions.
Yes, they are big-edian.
Does it work to add comments(about order and access functions) for the structure ahead of it?
And appending like "_be", "_access_be" or "_big_endian"? (struct mpc85xx_l2ctlr_be {……};
>Tabs in Linux are always 8 spaces wide.
>
I will re-confirm the v2 of identation.
>>
>> I looked at that patch.
>>
>> I don't think you can just drop the #ifdef in function
>> __access_remote_vm() in mm/memory.c
>>
>> You have to replace it with something like:
>>
>> if (!IS_ENABLED(CONFIG_HAVE_IOREMAP_PROT))
>> break;
>>
>
>
>Another thing in that patch:
>
>By making generic_access_phys() a static inline, it means that everytime
>you refer to the address of that function in a vm_operations_struct
>struct, the compiler has to provide an outlined instance of the
>function. It means you'll likely have several instances of a
>generic_access_phys().
>
>What you could do instead is to add the following at the start of
>generic_access_phys() in mm/memory.c :
>
> if (!IS_ENABLED(CONFIG_HAVE_IOREMAP_PROT))
> return 0;
>
It is really a better chmoce, thanks for the advice.
Multiple instances exist as you mentioned, the block returns 0 with no-op
instance which makes no difference with the function return value.
I will update the patch after a re-confirming.
Thanks,
Wenhu
next prev parent reply other threads:[~2022-06-14 7:54 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220609102855.272270-1-wenhu.wang@hotmail.com>
2022-06-09 10:28 ` [PATCH 1/2] powerpc:mm: export symbol ioremap_coherent Wang Wenhu
2022-06-14 10:45 ` Michael Ellerman
2022-06-14 14:49 ` Christoph Hellwig
2022-06-15 4:37 ` 回复: " Wenhu Wang
2022-06-09 10:28 ` [PATCH 2/2] uio:powerpc:mpc85xx: l2-cache-sram uio driver implementation Wang Wenhu
2022-06-09 13:17 ` Greg KH
2022-06-14 6:09 ` 回复: " Wenhu Wang
2022-06-14 6:34 ` Greg KH
2022-06-14 7:12 ` Christophe Leroy
2022-06-14 7:18 ` Christophe Leroy
2022-06-14 7:26 ` Christophe Leroy
2022-06-14 7:53 ` Wenhu Wang [this message]
2022-06-14 8:03 ` Greg KH
2022-06-14 8:39 ` Wenhu Wang
2022-06-14 14:40 ` Wenhu Wang
2022-06-14 14:59 ` Christophe Leroy
2022-06-15 6:04 ` 回复: " Christophe Leroy
2022-06-15 5:57 ` [PATCHv2 0/2] uio:powerpc:mpc85xx: l2-cache-sram uio driver Wang Wenhu
[not found] ` <20220615055735.53585-1-wenhu.wang@hotmail.com>
2022-06-15 5:57 ` [PATCHv2 1/2] mm: eliminate ifdef of HAVE_IOREMAP_PROT in .c files Wang Wenhu
2022-06-15 6:49 ` Christoph Hellwig
2022-06-22 2:22 ` kernel test robot
2022-06-22 4:13 ` kernel test robot
2022-06-15 5:57 ` [PATCHv2 2/2] uio:powerpc:mpc85xx: l2-cache-sram uio driver implementation Wang Wenhu
2022-06-15 6:43 ` Christoph Hellwig
2022-06-15 6:48 ` Christophe Leroy
2022-06-15 6:49 ` Christophe Leroy
2022-06-14 14:51 ` [PATCH " Christoph Hellwig
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