From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Alexander Gordeev <agordeev@linux.ibm.com>, Baoquan He <bhe@redhat.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<akpm@linux-foundation.org>, <hch@infradead.org>,
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 01/11] mm/ioremap: change the return value of io[re|un]map_allowed
Date: Sat, 6 Aug 2022 10:29:03 +0800 [thread overview]
Message-ID: <832b38ca-064e-0ab8-cd62-337d0d83d471@huawei.com> (raw)
In-Reply-To: <Yuvo9jWGL6VWStDO@li-4a3a4a4c-28e5-11b2-a85c-a8d192c6f089.ibm.com>
On 2022/8/4 23:42, Alexander Gordeev wrote:
> On Mon, Aug 01, 2022 at 10:40:19PM +0800, Baoquan He wrote:
>
> Hi Baoquan,
>
>> --- a/arch/arm64/mm/ioremap.c
>> +++ b/arch/arm64/mm/ioremap.c
>> @@ -3,19 +3,20 @@
>> #include <linux/mm.h>
>> #include <linux/io.h>
>>
>> -bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
>> +void __iomem *ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
>> {
>> unsigned long last_addr = phys_addr + size - 1;
>> + int ret = -EINVAL;
> If ret variable is really needed?
>
>> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
>> index 72974cb81343..d72eb310fb3c 100644
>> --- a/include/asm-generic/io.h
>> +++ b/include/asm-generic/io.h
>> @@ -967,26 +967,27 @@ static inline void iounmap(volatile void __iomem *addr)
>> /*
>> * Arch code can implement the following two hooks when using GENERIC_IOREMAP
>> * ioremap_allowed() return a bool,
>> - * - true means continue to remap
>> - * - false means skip remap and return directly
>> + * - IS_ERR means return an error
>> + * - NULL means continue to remap
>> + * - a non-NULL, non-IS_ERR pointer is returned directly
> If ioremap_allowed() returns a valid pointer, then the function name
> is not as precise anymore.
Maybe use arch_ioremap/unmap as before, or some better name.
>
>> @@ -28,8 +29,11 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
>> phys_addr -= offset;
>> size = PAGE_ALIGN(size + offset);
>>
>> - if (!ioremap_allowed(phys_addr, size, prot))
>> + base = ioremap_allowed(phys_addr, size, prot);
>> + if (IS_ERR(base))
>> return NULL;
>> + else if (base)
>> + return base;
> It is probably just me, but the base name bit misleading here.
We could reuse vaddr, not add new base.
>
>> @@ -50,9 +54,9 @@ EXPORT_SYMBOL(ioremap_prot);
>>
>> void iounmap(volatile void __iomem *addr)
>> {
>> - void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
>> + void __iomem *vaddr = (void __iomem *)((unsigned long)addr & PAGE_MASK);
>>
>> - if (!iounmap_allowed(vaddr))
>> + if (iounmap_allowed(vaddr))
> I guess, iounmap_allowed() should accept void __iomem *, not void *.
> Then addr needs to be passed to iounmap_allowed() not vaddr.
The following is_vmalloc_addr() and vunmap() in iounmap() use void *,
so we could simply use void* for iounmap_allowed().
>
>> return;
> .
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next prev parent reply other threads:[~2022-08-06 2:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 14:40 [PATCH 00/11] mm: ioremap: Convert architectures to take GENERIC_IOREMAP way Baoquan He
2022-08-01 14:40 ` [PATCH 01/11] mm/ioremap: change the return value of io[re|un]map_allowed Baoquan He
2022-08-04 15:42 ` Alexander Gordeev
2022-08-06 2:29 ` Kefeng Wang [this message]
2022-08-06 8:29 ` Alexander Gordeev
2022-08-07 1:42 ` Baoquan He
2022-08-07 1:51 ` Baoquan He
2022-08-07 1:58 ` Baoquan He
2022-08-01 14:40 ` [PATCH 02/11] mm: ioremap: fixup the physical address Baoquan He
2022-08-04 16:02 ` Alexander Gordeev
2022-08-07 2:11 ` Baoquan He
2022-08-20 0:49 ` Baoquan He
2022-08-01 14:40 ` [PATCH 03/11] mm: ioremap: allow ARCH to have its own ioremap definition Baoquan He
2022-08-01 14:40 ` [PATCH 04/11] arc: mm: Convert to GENERIC_IOREMAP Baoquan He
2022-08-01 14:40 ` [PATCH 05/11] hexagon: " Baoquan He
2022-08-01 14:40 ` [PATCH 06/11] ia64: " Baoquan He
2022-08-01 14:40 ` [PATCH 07/11] openrisc: " Baoquan He
2022-08-01 14:40 ` [PATCH 08/11] parisc: " Baoquan He
2022-08-01 14:40 ` [PATCH 09/11] s390: " Baoquan He
2022-08-01 14:40 ` [PATCH 10/11] sh: " Baoquan He
2022-08-01 14:40 ` [PATCH 11/11] xtensa: " Baoquan He
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