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Date:   Mon, 08 Mar 2021 11:20:57 +0000
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From:   Marc Zyngier <maz@kernel.org>
To:     Hector Martin <marcan@marcan.st>
Cc:     linux-arm-kernel@lists.infradead.org,
        Rob Herring <robh@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
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        Stan Skowronek <stan@corellium.com>,
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        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Corbet <corbet@lwn.net>,
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Subject: Re: [RFT PATCH v3 08/27] asm-generic/io.h:  Add a non-posted variant of ioremap()
In-Reply-To: <20210304213902.83903-9-marcan@marcan.st>
References: <20210304213902.83903-1-marcan@marcan.st>
        <20210304213902.83903-9-marcan@marcan.st>
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On Thu, 04 Mar 2021 21:38:43 +0000,
Hector Martin <marcan@marcan.st> wrote:
> 
> ARM64 currently defaults to posted MMIO (nGnRnE), but some devices
> require the use of non-posted MMIO (nGnRE). Introduce a new ioremap()
> variant to handle this case. ioremap_np() is aliased to ioremap() by
> default on arches that do not implement this variant.
> 
> sparc64 is the only architecture that needs to be touched directly,
> because it includes neither of the generic io.h or iomap.h headers.
> 
> This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this
> variant and marks a given resource as requiring non-posted mappings.
> This is implemented in the resource system because it is a SoC-level
> requirement, so existing drivers do not need special-case code to pick
> this ioremap variant.
> 
> Then this is implemented in devres by introducing devm_ioremap_np(),
> and making devm_ioremap_resource() automatically select this variant
> when the resource has the IORESOURCE_MEM_NONPOSTED flag set.
> 
> Signed-off-by: Hector Martin <marcan@marcan.st>

Acked-by: Marc Zyngier <maz@kernel.org>

	M.

-- 
Without deviation from the norm, progress is not possible.