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Subject: Re: [PATCH V3 1/2] ACPI / scan: Support multiple dma windows with
 different offsets
To:     Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc:     Robin Murphy <robin.murphy@arm.com>, chenhuacai@loongson.cn,
        guohanjun@huawei.com, sudeep.holla@arm.com, rafael@kernel.org,
        lenb@kernel.org, robert.moore@intel.com,
        linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
        loongarch@lists.linux.dev
References: <20220830030139.29899-1-lvjianmin@loongson.cn>
 <20220830030139.29899-2-lvjianmin@loongson.cn>
 <435e1283-9ff6-f089-6436-3c31a178fd60@arm.com>
 <66baf6f8-0f18-e0a6-4ed4-e2f783497d2d@loongson.cn>
 <YxrznBoBQycR8xCA@lpieralisi>
From:   Jianmin Lv <lvjianmin@loongson.cn>
Message-ID: <53c47160-ccee-a565-34cf-a7e5143744ed@loongson.cn>
Date:   Fri, 9 Sep 2022 17:23:07 +0800
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On 2022/9/9 下午4:04, Lorenzo Pieralisi wrote:
> On Tue, Sep 06, 2022 at 08:40:48PM +0800, Jianmin Lv wrote:
>>
>>
>> On 2022/9/5 下午8:20, Robin Murphy wrote:
>>> On 2022-08-30 04:01, Jianmin Lv wrote:
>>>> For DT, of_dma_get_range returns bus_dma_region typed dma regions,
>>>> which makes multiple dma windows with different offset available
>>>> for translation between dma address and cpu address.
>>>>
>>>> But for ACPI, acpi_dma_get_range doesn't return similar dma regions,
>>>> causing no path for setting dev->dma_range_map conveniently. So the
>>>> patch changes acpi_dma_get_range and returns bus_dma_region typed
>>>> dma regions according to of_dma_get_range.
>>>>
>>>> After changing acpi_dma_get_range, acpi_arch_dma_setup is changed for
>>>> ARM64, where original dma_addr and size are removed as these
>>>> arguments are now redundant, and pass 0 and U64_MAX for dma_base
>>>> and size of arch_setup_dma_ops, so this is a simplification consistent
>>>> with what other ACPI architectures also pass to iommu_setup_dma_ops().
>>>
>>> Other than a micro-nit that acpi_dma_get_range() could probably use
>>> resource_size(),
>>>
>>
>> Ok, thanks, I'll use resource_size() in acpi_dma_get_range().
> 
> Are you reposting this shortly ? We are almost at -rc5, it would
> be good if we can proceed promptly.
> 
> Thanks,
> Lorenzo
> 
Ok, I'll send V4 today.

Thanks,
Jianmin

>>> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
>>>
>>> It took me longer than I care to admit to figure out where the implicit
>>> declaration of struct bus_dma_region in the scope of acpi.h and
>>> acpi_bus.h comes from, but in the end I guess it's sufficiently
>>> well-defined by the C spec to be reliable.
>>>
>>> Thanks for getting this done!
>>>
>>
>> It's a pleasure!
>>
>>
>>> Robin.
>>>
>>
>> [...]
>>
>>