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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Cameron Berkenpas <cam@neo-zeon.de>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/mm/book3s64/hash: Update 4k PAGE_SIZE kernel mapping
Date: Wed, 16 Oct 2019 14:15:48 +0530	[thread overview]
Message-ID: <a06b0cb3-7d8f-a1e5-5eff-c1ba47276279@linux.ibm.com> (raw)
In-Reply-To: <20191016060556.GA7279@infradead.org>

On 10/16/19 11:35 AM, Christoph Hellwig wrote:
> On Wed, Oct 16, 2019 at 11:21:30AM +0530, Aneesh Kumar K.V wrote:
>> With commit: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel
>> regions in the same 0xc range"), kernel now split the 64TB address range
>> into 4 contexts each of 16TB. That implies we can do only 16TB linear
>> mapping. This results in boot failure on some P9 systems.
>>
>> Fix this by redoing the hash 4k mapping as below.
>>
>>   vmalloc start     = 0xd000000000000000
>>   IO start          = 0xd000380000000000
>>   vmemmap start     = 0xf000000000000000
>>
>> Vmalloc area is now 56TB in size and IO remap 8TB.
> 
> Btw, is there any good reason to keep the vmalloc and ioremap ranges
> separate on powerpc?  Most architectures just use the low-level vmap
> code to implement both and share a range.
> 

The base page size we use to map these two can be different.


-aneesh

  reply	other threads:[~2019-10-16  8:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-16  5:51 [PATCH] powerpc/mm/book3s64/hash: Update 4k PAGE_SIZE kernel mapping Aneesh Kumar K.V
2019-10-16  6:05 ` Christoph Hellwig
2019-10-16  8:45   ` Aneesh Kumar K.V [this message]
2019-10-16  9:30   ` Michael Ellerman
2019-10-17  2:18     ` Benjamin Herrenschmidt
2019-10-16 16:21 ` Cameron Berkenpas

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