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From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Suzuki K Poulose <suzuki.poulose@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com,
	maz@kernel.org, james.morse@arm.com, steven.price@arm.com
Subject: Re: [RFC V3 07/13] arm64/mm: Add FEAT_LPA2 specific encoding
Date: Wed, 13 Oct 2021 08:25:57 +0530	[thread overview]
Message-ID: <5981c5d0-0b46-f942-af6d-7692a593cb38@arm.com> (raw)
In-Reply-To: <e78741a0-8a45-5460-3a95-5eb42c63d055@arm.com>



On 10/12/21 4:11 PM, Suzuki K Poulose wrote:
> On 30/09/2021 11:35, Anshuman Khandual wrote:
>> FEAT_LPA2 requires different PTE representation formats for both 4K and 16K
>> page size config. This adds FEAT_LPA2 specific new PTE encodings as per ARM
>> ARM (0487G.A) which updates [pte|phys]_to_[phys|pte](). The updated helpers
>> would be used when FEAT_LPA2 gets enabled via CONFIG_ARM64_PA_BITS_52 on 4K
>> and 16K page size. Although TTBR encoding and phys_to_ttbr() helper remains
>> the same as FEAT_LPA for FEAT_LPA2 as well. It updates 'phys_to_pte' helper
>> to accept a temporary variable and changes impacted call sites.
>>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>   arch/arm64/include/asm/assembler.h     | 14 +++++++++++---
>>   arch/arm64/include/asm/pgtable-hwdef.h |  4 ++++
>>   arch/arm64/include/asm/pgtable.h       |  4 ++++
>>   3 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
>> index 3fbe04a..c1543067 100644
>> --- a/arch/arm64/include/asm/assembler.h
>> +++ b/arch/arm64/include/asm/assembler.h
>> @@ -628,6 +628,10 @@ alternative_endif
>>        */
>>       orr    \pte, \phys, \phys, lsr #36
>>       and    \pte, \pte, #PTE_ADDR_MASK
>> +#elif defined(CONFIG_ARM64_PA_BITS_52_LPA2)
>> +    orr    \pte, \phys, \phys, lsr #42
>> +    and    \pte, \pte, #PTE_ADDR_MASK | GENMASK(PAGE_SHIFT - 1, 10)
>> +    and    \pte, \pte, #~GENMASK(PAGE_SHIFT - 1, 10)
>>   #else  /* !CONFIG_ARM64_PA_BITS_52_LPA */
>>       mov    \pte, \phys
>>   #endif /* CONFIG_ARM64_PA_BITS_52_LPA */
>> @@ -635,9 +639,13 @@ alternative_endif
>>         .macro    pte_to_phys, phys, pte
>>   #ifdef CONFIG_ARM64_PA_BITS_52_LPA
>> -    ubfiz    \phys, \pte, #(48 - 16 - 12), #16
>> -    bfxil    \phys, \pte, #16, #32
>> -    lsl    \phys, \phys, #16
>> +    ubfiz    \phys, \pte, #(48 - PAGE_SHIFT - 12), #16
>> +    bfxil    \phys, \pte, #PAGE_SHIFT, #(48 - PAGE_SHIFT)
> 
> nit: This looks like an unrelated change and is better suited for the previous patch.

Changed the existing FEAT_LPA encodings here to use PAGE_SHIFT just
to match the new ones being added for FEAT_LPA2. But reasonable for
them to be folded into the previous patch instead.

  reply	other threads:[~2021-10-13  2:56 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-30 10:35 [RFC V3 00/13] arm64/mm: Enable FEAT_LPA2 (52 bits PA support on 4K|16K pages) Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 01/13] arm64/mm: Dynamically initialize protection_map[] Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 02/13] arm64/mm: Consolidate TCR_EL1 fields Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 03/13] arm64/mm: Add FEAT_LPA2 specific TCR_EL1.DS field Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 04/13] arm64/mm: Add FEAT_LPA2 specific VTCR_EL2.DS field Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 05/13] arm64/mm: Add FEAT_LPA2 specific ID_AA64MMFR0.TGRAN[2] Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 06/13] arm64/mm: Add CONFIG_ARM64_PA_BITS_52_[LPA|LPA2] Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 07/13] arm64/mm: Add FEAT_LPA2 specific encoding Anshuman Khandual
2021-10-12 10:41   ` Suzuki K Poulose
2021-10-13  2:55     ` Anshuman Khandual [this message]
2021-09-30 10:35 ` [RFC V3 08/13] arm64/mm: Detect and enable FEAT_LPA2 Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 09/13] arm64/mm: Add __cpu_secondary_check52bitpa() Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 10/13] arm64/mm: Add FEAT_LPA2 specific PTE_SHARED and PMD_SECT_S Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 11/13] arm64/mm: Add FEAT_LPA2 specific fallback (48 bits PA) when not implemented Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 12/13] arm64/mm: Enable CONFIG_ARM64_PA_BITS_52 on CONFIG_ARM64_[4K|16K]_PAGES Anshuman Khandual
2021-09-30 10:35 ` [RFC V3 13/13] KVM: arm64: Enable FEAT_LPA2 based 52 bits IPA size on 4K and 16K Anshuman Khandual
2021-10-11 10:16   ` Marc Zyngier
2021-10-12  4:24     ` Anshuman Khandual
2021-10-12  8:30       ` Marc Zyngier
2021-10-13  3:28         ` Anshuman Khandual

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