From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 4/6] ARM: mm: LPAE: Correct virt_to_phys patching for 64 bit physical addresses
Date: Mon, 5 Aug 2013 10:38:13 -0400 [thread overview]
Message-ID: <51FFB8D5.8070506@ti.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1308040126560.14472@syhkavp.arg>
On Sunday 04 August 2013 01:32 AM, Nicolas Pitre wrote:
> On Sat, 3 Aug 2013, Santosh Shilimkar wrote:
>
>> On Saturday 03 August 2013 10:01 AM, Nicolas Pitre wrote:
>>> On Sat, 3 Aug 2013, Sricharan R wrote:
>>>
>>>> On Saturday 03 August 2013 08:58 AM, Nicolas Pitre wrote:
>>>>> ... meaning that, instead of using 0x81 for the stub value on the mov
>>>>> instruction, it only has to be 0x83. Bits 7 and 0 still act as anchors
>>>>> for the rotation field in the opcode, while bit 1 indicates which value
>>>>> to patch in.
>>>> I started with this kind of augmenting with the immediate operand
>>>> while starting V2. But the problem was, we do the runtime patching twice.
>>>
>>> Ahhh... Bummer.
>>>
>> Sorry if it wasn't clear but I thought we discussed why patching is
>> done twice.
>
> Yeah, I know the reasons. I just had forgotten about the effects on the
> anchor bits.
>
I see.
>> This was purely based on the discussion where RMK suggested to follow
>> that approach to minimize code changes.
>>
>> Looks like we need to revisit that now based on Russell's latest
>> comment.
>
> Note that my comments on this particular patch are still valid and
> independent from whatever approach is used globally to deal with the
> memory alias. I do think that the value to patch should be selected
> depending on the opcode's rotation field which makes it compatible with
> a double patching approach as well.
>
Completely agree.
Regards,
Santosh
next prev parent reply other threads:[~2013-08-05 14:38 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-31 16:44 [PATCH v2 0/6] ARM: mm: Extend the runtime patch stub for PAE systems Santosh Shilimkar
2013-07-31 16:44 ` [PATCH v2 1/6] ARM: mm: LPAE: use phys_addr_t appropriately in p2v and v2p conversions Santosh Shilimkar
2013-07-31 16:44 ` [PATCH v2 2/6] ARM: mm: Introduce virt_to_idmap() with an arch hook Santosh Shilimkar
2013-08-03 1:53 ` Nicolas Pitre
2013-08-03 19:03 ` Santosh Shilimkar
2013-07-31 16:44 ` [PATCH v2 3/6] ARM: mm: Move the idmap print to appropriate place in the code Santosh Shilimkar
2013-08-03 1:55 ` Nicolas Pitre
2013-07-31 16:44 ` [PATCH v2 4/6] ARM: mm: LPAE: Correct virt_to_phys patching for 64 bit physical addresses Santosh Shilimkar
2013-07-31 18:31 ` Sricharan R
2013-08-03 3:32 ` Nicolas Pitre
2013-08-03 3:28 ` Nicolas Pitre
2013-08-03 12:47 ` Sricharan R
2013-08-03 14:01 ` Nicolas Pitre
2013-08-03 19:25 ` Santosh Shilimkar
2013-08-04 5:32 ` Nicolas Pitre
2013-08-05 14:38 ` Santosh Shilimkar [this message]
2013-08-03 14:05 ` Russell King - ARM Linux
2013-08-03 14:09 ` Russell King - ARM Linux
2013-08-03 19:15 ` Santosh Shilimkar
2013-08-09 19:37 ` Santosh Shilimkar
2013-07-31 16:44 ` [PATCH v2 5/6] ARM: mm: Update runtime patching code to THUMB2 mode Santosh Shilimkar
2013-08-03 3:40 ` Nicolas Pitre
2013-08-03 12:51 ` Sricharan R
2013-07-31 16:44 ` [PATCH v2 6/6] ARM: mm: Recreate kernel mappings in early_paging_init() Santosh Shilimkar
2013-08-03 1:52 ` [PATCH v2 0/6] ARM: mm: Extend the runtime patch stub for PAE systems Nicolas Pitre
2013-08-03 19:02 ` Santosh Shilimkar
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