From: Christoph Hellwig <hch@lst.de>
To: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Ard Biesheuvel <ardb@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
wsd_upstream <wsd_upstream@mediatek.com>,
linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING
Date: Thu, 4 Nov 2021 09:53:36 +0100 [thread overview]
Message-ID: <20211104085336.GA24260@lst.de> (raw)
In-Reply-To: <20211104023221.16391-1-walter-zh.wu@mediatek.com>
On Thu, Nov 04, 2021 at 10:32:21AM +0800, Walter Wu wrote:
> diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
> index f36be5166c19..6c7d1683339c 100644
> --- a/include/linux/set_memory.h
> +++ b/include/linux/set_memory.h
> @@ -7,11 +7,16 @@
>
> #ifdef CONFIG_ARCH_HAS_SET_MEMORY
> #include <asm/set_memory.h>
> +
> +#ifndef CONFIG_RODATA_FULL_DEFAULT_ENABLED
This is an arm64-specific symbol, and one that only controls a
default. I don't think it is suitable to key off stubs in common
code.
> +static inline int set_memory_valid(unsigned long addr, int numpages, int enable) { return 0; }
Pleae avoid overly long lines.
> + if (IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED)) {
> + kaddr = (unsigned long)phys_to_virt(dma_to_phys(dev, *dma_handle));
This can just use page_address.
> + /* page remove kernel mapping for arm64 */
> + set_memory_valid(kaddr, size >> PAGE_SHIFT, 0);
> + }
But more importantly: set_memory_valid only exists on arm64, this
will break compile everywhere else. And this API is complete crap.
Passing kernel virtual addresses as unsigned long just sucks, and
passing an integer argument for valid/non-valid also is a horrible
API.
Not to mention the overly long line. Same on the free side.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Walter Wu <walter-zh.wu@mediatek.com>
Cc: wsd_upstream <wsd_upstream@mediatek.com>,
linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
iommu@lists.linux-foundation.org,
linux-mediatek@lists.infradead.org,
Matthias Brugger <matthias.bgg@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Robin Murphy <robin.murphy@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING
Date: Thu, 4 Nov 2021 09:53:36 +0100 [thread overview]
Message-ID: <20211104085336.GA24260@lst.de> (raw)
In-Reply-To: <20211104023221.16391-1-walter-zh.wu@mediatek.com>
On Thu, Nov 04, 2021 at 10:32:21AM +0800, Walter Wu wrote:
> diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
> index f36be5166c19..6c7d1683339c 100644
> --- a/include/linux/set_memory.h
> +++ b/include/linux/set_memory.h
> @@ -7,11 +7,16 @@
>
> #ifdef CONFIG_ARCH_HAS_SET_MEMORY
> #include <asm/set_memory.h>
> +
> +#ifndef CONFIG_RODATA_FULL_DEFAULT_ENABLED
This is an arm64-specific symbol, and one that only controls a
default. I don't think it is suitable to key off stubs in common
code.
> +static inline int set_memory_valid(unsigned long addr, int numpages, int enable) { return 0; }
Pleae avoid overly long lines.
> + if (IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED)) {
> + kaddr = (unsigned long)phys_to_virt(dma_to_phys(dev, *dma_handle));
This can just use page_address.
> + /* page remove kernel mapping for arm64 */
> + set_memory_valid(kaddr, size >> PAGE_SHIFT, 0);
> + }
But more importantly: set_memory_valid only exists on arm64, this
will break compile everywhere else. And this API is complete crap.
Passing kernel virtual addresses as unsigned long just sucks, and
passing an integer argument for valid/non-valid also is a horrible
API.
Not to mention the overly long line. Same on the free side.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Ard Biesheuvel <ardb@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
wsd_upstream <wsd_upstream@mediatek.com>,
linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING
Date: Thu, 4 Nov 2021 09:53:36 +0100 [thread overview]
Message-ID: <20211104085336.GA24260@lst.de> (raw)
In-Reply-To: <20211104023221.16391-1-walter-zh.wu@mediatek.com>
On Thu, Nov 04, 2021 at 10:32:21AM +0800, Walter Wu wrote:
> diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
> index f36be5166c19..6c7d1683339c 100644
> --- a/include/linux/set_memory.h
> +++ b/include/linux/set_memory.h
> @@ -7,11 +7,16 @@
>
> #ifdef CONFIG_ARCH_HAS_SET_MEMORY
> #include <asm/set_memory.h>
> +
> +#ifndef CONFIG_RODATA_FULL_DEFAULT_ENABLED
This is an arm64-specific symbol, and one that only controls a
default. I don't think it is suitable to key off stubs in common
code.
> +static inline int set_memory_valid(unsigned long addr, int numpages, int enable) { return 0; }
Pleae avoid overly long lines.
> + if (IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED)) {
> + kaddr = (unsigned long)phys_to_virt(dma_to_phys(dev, *dma_handle));
This can just use page_address.
> + /* page remove kernel mapping for arm64 */
> + set_memory_valid(kaddr, size >> PAGE_SHIFT, 0);
> + }
But more importantly: set_memory_valid only exists on arm64, this
will break compile everywhere else. And this API is complete crap.
Passing kernel virtual addresses as unsigned long just sucks, and
passing an integer argument for valid/non-valid also is a horrible
API.
Not to mention the overly long line. Same on the free side.
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Ard Biesheuvel <ardb@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
wsd_upstream <wsd_upstream@mediatek.com>,
linux-mediatek@lists.infradead.org
Subject: Re: [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING
Date: Thu, 4 Nov 2021 09:53:36 +0100 [thread overview]
Message-ID: <20211104085336.GA24260@lst.de> (raw)
In-Reply-To: <20211104023221.16391-1-walter-zh.wu@mediatek.com>
On Thu, Nov 04, 2021 at 10:32:21AM +0800, Walter Wu wrote:
> diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
> index f36be5166c19..6c7d1683339c 100644
> --- a/include/linux/set_memory.h
> +++ b/include/linux/set_memory.h
> @@ -7,11 +7,16 @@
>
> #ifdef CONFIG_ARCH_HAS_SET_MEMORY
> #include <asm/set_memory.h>
> +
> +#ifndef CONFIG_RODATA_FULL_DEFAULT_ENABLED
This is an arm64-specific symbol, and one that only controls a
default. I don't think it is suitable to key off stubs in common
code.
> +static inline int set_memory_valid(unsigned long addr, int numpages, int enable) { return 0; }
Pleae avoid overly long lines.
> + if (IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED)) {
> + kaddr = (unsigned long)phys_to_virt(dma_to_phys(dev, *dma_handle));
This can just use page_address.
> + /* page remove kernel mapping for arm64 */
> + set_memory_valid(kaddr, size >> PAGE_SHIFT, 0);
> + }
But more importantly: set_memory_valid only exists on arm64, this
will break compile everywhere else. And this API is complete crap.
Passing kernel virtual addresses as unsigned long just sucks, and
passing an integer argument for valid/non-valid also is a horrible
API.
Not to mention the overly long line. Same on the free side.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-11-04 8:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 2:32 [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING Walter Wu
2021-11-04 2:32 ` Walter Wu
2021-11-04 2:32 ` Walter Wu
2021-11-04 2:32 ` Walter Wu
2021-11-04 8:53 ` Christoph Hellwig [this message]
2021-11-04 8:53 ` Christoph Hellwig
2021-11-04 8:53 ` Christoph Hellwig
2021-11-04 8:53 ` Christoph Hellwig
2021-11-04 8:57 ` Ard Biesheuvel
2021-11-04 8:57 ` Ard Biesheuvel
2021-11-04 8:57 ` Ard Biesheuvel
2021-11-04 8:57 ` Ard Biesheuvel
2021-11-04 12:31 ` Walter Wu
2021-11-04 12:31 ` Walter Wu
2021-11-04 12:31 ` Walter Wu
2021-11-04 12:31 ` Walter Wu
2021-11-04 12:47 ` Ard Biesheuvel
2021-11-04 12:47 ` Ard Biesheuvel
2021-11-04 12:47 ` Ard Biesheuvel
2021-11-04 12:47 ` Ard Biesheuvel
2021-11-04 13:40 ` Walter Wu
2021-11-04 13:40 ` Walter Wu
2021-11-04 13:40 ` Walter Wu
2021-11-04 13:40 ` Walter Wu
2021-11-04 16:22 ` Ard Biesheuvel
2021-11-04 16:22 ` Ard Biesheuvel
2021-11-04 16:22 ` Ard Biesheuvel
2021-11-04 16:22 ` Ard Biesheuvel
2021-11-04 12:18 ` Walter Wu
2021-11-04 12:18 ` Walter Wu
2021-11-04 12:18 ` Walter Wu
2021-11-04 12:18 ` Walter Wu
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=20211104085336.GA24260@lst.de \
--to=hch@lst.de \
--cc=akpm@linux-foundation.org \
--cc=ardb@kernel.org \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=m.szyprowski@samsung.com \
--cc=matthias.bgg@gmail.com \
--cc=robin.murphy@arm.com \
--cc=walter-zh.wu@mediatek.com \
--cc=wsd_upstream@mediatek.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.