From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Christoph Hellwig <hch@lst.de>,
linux-arch <linux-arch@vger.kernel.org>,
Ira Weiny <ira.weiny@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: flush_dcache_page vs kunmap_local
Date: Thu, 4 Nov 2021 18:20:37 +0000 [thread overview]
Message-ID: <YYQkdUcSLFPlzGFH@shell.armlinux.org.uk> (raw)
In-Reply-To: <YYQgvTn2NQdZK2Ku@arm.com>
On Thu, Nov 04, 2021 at 06:04:45PM +0000, Catalin Marinas wrote:
> The cachetlb.rst doc states the two cases where flush_dcache_page()
> should be called:
>
> 1. After writing to a page cache page (that's what we need on arm64 for
> the I-cache).
>
> 2. Before reading from a page cache page and user mappings potentially
> exist. I think arm32 ensures the D-cache user aliases are coherent
> with the kernel one (added rmk to confirm).
Yes, where necessary, we flush the user aliases in flush_dcache_page().
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2021-11-04 18:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 15:00 flush_dcache_page vs kunmap_local Matthew Wilcox
2021-11-04 15:30 ` Linus Torvalds
2021-11-04 16:54 ` Catalin Marinas
2021-11-04 17:08 ` Linus Torvalds
2021-11-04 18:04 ` Catalin Marinas
2021-11-04 18:20 ` Russell King (Oracle) [this message]
2021-11-04 18:23 ` Linus Torvalds
2021-11-05 19:40 ` Catalin Marinas
2021-11-04 18:38 ` Matthew Wilcox
2021-11-04 21:02 ` Linus Torvalds
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