From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] KVM: arm64: Drop direct PAGE_[SHIFT|SIZE] usage as page size
Date: Wed, 11 Aug 2021 11:04:46 +0530 [thread overview]
Message-ID: <0b47c654-7e9b-a7ca-bdf4-f9607062200e@arm.com> (raw)
In-Reply-To: <25ee7799069492f2501003faec7f9732@kernel.org>
On 8/10/21 7:03 PM, Marc Zyngier wrote:
> On 2021-08-10 08:02, Anshuman Khandual wrote:
>> All instances here could just directly test against CONFIG_ARM64_XXK_PAGES
>> instead of evaluating via PAGE_SHIFT or PAGE_SIZE. With this change, there
>> will be no such usage left.
>>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Cc: James Morse <james.morse@arm.com>
>> Cc: Alexandru Elisei <alexandru.elisei@arm.com>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: kvmarm@lists.cs.columbia.edu
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> arch/arm64/kvm/hyp/pgtable.c | 6 +++---
>> arch/arm64/mm/mmu.c | 2 +-
>> 2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
>> index 05321f4165e3..a6112b6d6ef6 100644
>> --- a/arch/arm64/kvm/hyp/pgtable.c
>> +++ b/arch/arm64/kvm/hyp/pgtable.c
>> @@ -85,7 +85,7 @@ static bool kvm_level_supports_block_mapping(u32 level)
>> * Reject invalid block mappings and don't bother with 4TB mappings for
>> * 52-bit PAs.
>> */
>> - return !(level == 0 || (PAGE_SIZE != SZ_4K && level == 1));
>> + return !(level == 0 || (!IS_ENABLED(CONFIG_ARM64_4K_PAGES) && level == 1));
>> }
>>
>> static bool kvm_block_mapping_supported(u64 addr, u64 end, u64 phys, u32 level)
>> @@ -155,7 +155,7 @@ static u64 kvm_pte_to_phys(kvm_pte_t pte)
>> {
>> u64 pa = pte & KVM_PTE_ADDR_MASK;
>>
>> - if (PAGE_SHIFT == 16)
>> + if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
>> pa |= FIELD_GET(KVM_PTE_ADDR_51_48, pte) << 48;
>>
>> return pa;
>> @@ -165,7 +165,7 @@ static kvm_pte_t kvm_phys_to_pte(u64 pa)
>> {
>> kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK;
>>
>> - if (PAGE_SHIFT == 16)
>> + if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
>> pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48);
>>
>> return pte;
>> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
>> index 9ff0de1b2b93..8fdfca179815 100644
>> --- a/arch/arm64/mm/mmu.c
>> +++ b/arch/arm64/mm/mmu.c
>> @@ -296,7 +296,7 @@ static void alloc_init_cont_pmd(pud_t *pudp,
>> unsigned long addr,
>> static inline bool use_1G_block(unsigned long addr, unsigned long next,
>> unsigned long phys)
>> {
>> - if (PAGE_SHIFT != 12)
>> + if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES))
>> return false;
>>
>> if (((addr | next | phys) & ~PUD_MASK) != 0)
>
> I personally find it a lot less readable.
>
> Also, there is no evaluation whatsoever. All the code guarded
> by a PAGE_SIZE/PAGE_SHIFT that doesn't match the configuration
> is dropped at compile time.
The primary idea here is to unify around IS_ENABLED(CONFIG_ARM64_XXK_PAGES)
usage in arm64, rather than having multiple methods to test page size when
ever required.
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next prev parent reply other threads:[~2021-08-11 5:36 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-10 7:02 [PATCH 0/5] KVM: arm64: General cleanups Anshuman Khandual
2021-08-10 7:02 ` [PATCH 1/5] KVM: arm64: Drop direct PAGE_[SHIFT|SIZE] usage as page size Anshuman Khandual
2021-08-10 13:20 ` Will Deacon
2021-08-11 5:32 ` Anshuman Khandual
2021-08-10 13:33 ` Marc Zyngier
2021-08-11 5:34 ` Anshuman Khandual [this message]
2021-08-11 8:11 ` Marc Zyngier
2021-08-11 9:37 ` Anshuman Khandual
2021-08-11 10:13 ` Marc Zyngier
2021-08-10 7:02 ` [PATCH 2/5] KVM: arm64: Drop init_common_resources() Anshuman Khandual
2021-08-10 13:21 ` Will Deacon
2021-08-10 15:11 ` Anshuman Khandual
2021-08-10 7:02 ` [PATCH 3/5] KVM: arm64: Drop check_kvm_target_cpu() based percpu probe Anshuman Khandual
2021-08-10 13:28 ` Will Deacon
2021-08-11 5:54 ` Anshuman Khandual
2021-08-10 7:02 ` [PATCH 4/5] KVM: arm64: Drop unused REQUIRES_VIRT Anshuman Khandual
2021-08-10 7:02 ` [PATCH 5/5] KVM: arm64: Define KVM_PHYS_SHIFT_MIN Anshuman Khandual
2021-08-10 13:29 ` Marc Zyngier
2021-08-10 15:19 ` Anshuman Khandual
2021-08-10 15:32 ` Marc Zyngier
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