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Subject: Re: [PATCH v2] MIPS: replace add_memory_region with memblock
To:     Serge Semin <fancer.lancer@gmail.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc:     Hauke Mehrtens <hauke@hauke-m.de>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        bcm-kernel-feedback-list@broadcom.com,
        "Maciej W. Rozycki" <macro@linux-mips.org>,
        Keguang Zhang <keguang.zhang@gmail.com>,
        John Crispin <john@phrozen.org>, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
References: <20201008084357.42780-1-tsbogend@alpha.franken.de>
 <20201008152006.4khkbzsxqmmz76rw@mobilestation>
From:   Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-ID: <631aa35e-2575-3ec0-ec0f-7d45e49b8373@flygoat.com>
Date:   Fri, 9 Oct 2020 11:00:36 +0800
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在 2020/10/8 23:20, Serge Semin 写道:

[...]
>
>> -		add_memory_region(LOONGSON_HIGHMEM_START,
>> -				  highmemsize << 20, BOOT_MEM_RAM);
>> -
>> -	add_memory_region(LOONGSON_PCI_MEM_END + 1, LOONGSON_HIGHMEM_START -
>> -			  LOONGSON_PCI_MEM_END - 1, BOOT_MEM_RESERVED);
>> -
>> +		memblock_add(LOONGSON_HIGHMEM_START, highmemsize << 20);
> The same question. Is it ok to discard the
> [LOONGSON_PCI_MEM_END+1:LOONGSON_HIGHMEM_START-LOONGSON_PCI_MEM_END-1] region
> removal operation?
Hi all,

I can confirm this reservation can be removed.
It was used to ensure HIGHMEM won't overlap PCI MMIO region when
firmware was unreliable.
But I do think we shouldn't care this case as an unreliable firmware 
shouldn't
ship with any devices for end users.

Also it won't affect display of /proc/iomem, now we're on age of 
DeviceTree :-)

Thanks.

- Jiaxun

>
> -Sergey
>
>>   #endif /* !CONFIG_64BIT */
>>   }
>>