Re: [PATCH V7 05/10] acpi: apei: handle SEA notification type for ARMv8

From: James Morse <james.morse-5wv7dgnIgG8@public.gmane.org>
To: "Baicar, Tyler" <tbaicar-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
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Subject: Re: [PATCH V7 05/10] acpi: apei: handle SEA notification type for ARMv8
Date: Tue, 24 Jan 2017 17:55:32 +0000	[thread overview]
Message-ID: <58879514.1020501@arm.com> (raw)
In-Reply-To: <8b9d254a-5450-d841-baf7-5819a88043e4-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Hi Tyler,

On 20/01/17 20:58, Baicar, Tyler wrote:
> On 1/19/2017 10:57 AM, James Morse wrote:
>> On 18/01/17 23:51, Baicar, Tyler wrote:
>>> On 1/18/2017 7:50 AM, James Morse wrote:
>>>> On 12/01/17 18:15, Tyler Baicar wrote:
>>>>> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c

>> There are two other things that need changing to make the in_nmi() code path
>> work on arm64.
>> Always reserve the virtual-address-space forcing GHES_IOREMAP_PAGES to be 2
>> regardless of CONFIG_HAVE_ACPI_APEI_NMI. This is almost revert of
>> 594c7255dce7a13cac50cf2470cc56e2c3b0494e (but that did a few other things too).

> Looks simple enough, should I force it to 2 in all cases, or add a check for
> CONFIG_HAVE_ACPI_APEI_SEA
> similar to the check for CONFIG_HAVE_ACPI_APEI_NMI?

Its just address space not actual memory it is reserving right? I think just
reserve two pages all the time to save eye-sore #ifdefs!

>> We also need to fix ghes_ioremap_pfn_nmi() to use arch_apei_get_mem_attribute()
>> and not assume PAGE_KERNEL.

> So just change the call to ioremap_page_range to:
> 
> ioremap_page_range(vaddr, vaddr + PAGE_SIZE, pfn << PAGE_SHIFT,
> arch_apei_get_mem_attribute());

(you need to give arch_apei_get_mem_attribute() the address...) copying whatever
ghes_ioremap_pfn_irq() does a few lines down is probably best.

Thanks,

James