From: Alex Ghiti <alex@ghiti.fr>
To: Palmer Dabbelt <palmer@dabbelt.com>
Cc: anup@brainfault.org, linux-kernel@vger.kernel.org,
zong.li@sifive.com, Paul Walmsley <paul.walmsley@sifive.com>,
linux-riscv@lists.infradead.org, Christoph Hellwig <hch@lst.de>
Subject: Re: [RFC PATCH 2/7] riscv: Allow to dynamically define VA_BITS
Date: Tue, 7 Apr 2020 01:12:31 -0400 [thread overview]
Message-ID: <8922d36f-1b4e-0575-33e7-197e3f0b3817@ghiti.fr> (raw)
In-Reply-To: <mhng-1f8477e3-7cb4-454f-b443-8cf032325385@palmerdabbelt-glaptop1>
On 4/3/20 11:17 AM, Palmer Dabbelt wrote:
> On Sun, 22 Mar 2020 04:00:23 PDT (-0700), alex@ghiti.fr wrote:
>> With 4-level page table folding at runtime, we don't know at compile time
>> the size of the virtual address space so we must set VA_BITS dynamically
>> so that sparsemem reserves the right amount of memory for struct pages.
>>
>> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
>> ---
>> arch/riscv/Kconfig | 10 ----------
>> arch/riscv/include/asm/pgtable.h | 10 +++++++++-
>> arch/riscv/include/asm/sparsemem.h | 2 +-
>> 3 files changed, 10 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index f5f3d474504d..8e4b1cbcf2c2 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -99,16 +99,6 @@ config ZONE_DMA32
>> bool
>> default y if 64BIT
>>
>> -config VA_BITS
>> - int
>> - default 32 if 32BIT
>> - default 39 if 64BIT
>> -
>> -config PA_BITS
>> - int
>> - default 34 if 32BIT
>> - default 56 if 64BIT
>> -
>> config PAGE_OFFSET
>> hex
>> default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
>> diff --git a/arch/riscv/include/asm/pgtable.h
>> b/arch/riscv/include/asm/pgtable.h
>> index 185ffe3723ec..dce401eed1d3 100644
>> --- a/arch/riscv/include/asm/pgtable.h
>> +++ b/arch/riscv/include/asm/pgtable.h
>> @@ -26,6 +26,14 @@
>> #endif /* CONFIG_64BIT */
>>
>> #ifdef CONFIG_MMU
>> +#ifdef CONFIG_64BIT
>> +#define VA_BITS 39
>> +#define PA_BITS 56
>> +#else
>> +#define VA_BITS 32
>> +#define PA_BITS 34
>
> We've moved to 32-bit physical addresses on rv32 in Linux. The mismatch
> was
> causing too many issues in generic code.
Ok I missed this one, thanks.
>
>> +#endif
>> +
>> /* Number of entries in the page global directory */
>> #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t))
>> /* Number of entries in the page table */
>> @@ -108,7 +116,7 @@ extern pgd_t swapper_pg_dir[];
>> * position vmemmap directly below the VMALLOC region.
>> */
>> #define VMEMMAP_SHIFT \
>> - (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>> + (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
>> #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT)
>> #define VMEMMAP_END (VMALLOC_START - 1)
>> #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE)
>> diff --git a/arch/riscv/include/asm/sparsemem.h
>> b/arch/riscv/include/asm/sparsemem.h
>> index 45a7018a8118..f08d72155bc8 100644
>> --- a/arch/riscv/include/asm/sparsemem.h
>> +++ b/arch/riscv/include/asm/sparsemem.h
>> @@ -4,7 +4,7 @@
>> #define _ASM_RISCV_SPARSEMEM_H
>>
>> #ifdef CONFIG_SPARSEMEM
>> -#define MAX_PHYSMEM_BITS CONFIG_PA_BITS
>> +#define MAX_PHYSMEM_BITS PA_BITS
>> #define SECTION_SIZE_BITS 27
>> #endif /* CONFIG_SPARSEMEM */
>
> Aside from the 32-bit PA issue:
>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Thanks,
Alex
next prev parent reply other threads:[~2020-04-07 5:12 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-22 11:00 [RFC PATCH 0/7] Introduce sv48 support Alexandre Ghiti
2020-03-22 11:00 ` [RFC PATCH 1/7] riscv: Get rid of compile time logic with MAX_EARLY_MAPPING_SIZE Alexandre Ghiti
2020-03-26 6:10 ` Anup Patel
2020-04-03 15:17 ` Palmer Dabbelt
2020-04-07 5:12 ` Alex Ghiti
2020-03-22 11:00 ` [RFC PATCH 2/7] riscv: Allow to dynamically define VA_BITS Alexandre Ghiti
2020-03-26 6:12 ` Anup Patel
2020-04-03 15:17 ` Palmer Dabbelt
2020-04-07 5:12 ` Alex Ghiti [this message]
2020-03-22 11:00 ` [RFC PATCH 3/7] riscv: Simplify MAXPHYSMEM config Alexandre Ghiti
2020-03-26 6:22 ` Anup Patel
2020-03-26 6:34 ` Anup Patel
2020-04-03 15:53 ` Palmer Dabbelt
2020-04-07 5:13 ` Alex Ghiti
2020-03-22 11:00 ` [RFC PATCH 4/7] riscv: Implement sv48 support Alexandre Ghiti
2020-03-26 7:00 ` Anup Patel
2020-03-31 16:31 ` Alex Ghiti
2020-04-03 15:53 ` Palmer Dabbelt
2020-04-07 5:14 ` Alex Ghiti
2020-04-07 5:56 ` Anup Patel
2020-04-08 4:39 ` Alex Ghiti
2020-04-08 5:06 ` Anup Patel
2020-03-22 11:00 ` [RFC PATCH 5/7] riscv: Use pgtable_l4_enabled to output mmu type in cpuinfo Alexandre Ghiti
2020-03-26 7:01 ` Anup Patel
2020-04-03 15:53 ` Palmer Dabbelt
2020-04-07 5:14 ` Alex Ghiti
2020-03-22 11:00 ` [RFC PATCH 6/7] dt-bindings: riscv: Remove "riscv, svXX" property from device-tree Alexandre Ghiti
2020-03-26 7:03 ` Anup Patel
2020-04-03 15:53 ` Palmer Dabbelt
2020-04-07 5:14 ` Alex Ghiti
2020-03-22 11:00 ` [RFC PATCH 7/7] riscv: Explicit comment about user virtual address space size Alexandre Ghiti
2020-03-26 7:05 ` Anup Patel
2020-04-03 15:53 ` Palmer Dabbelt
2020-04-07 5:15 ` Alex Ghiti
2020-03-31 19:53 ` [RFC PATCH 0/7] Introduce sv48 support Palmer Dabbelt
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