From: Ard Biesheuvel <ardb@kernel.org> To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel <ardb@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Ryan Roberts <ryan.roberts@arm.com>, Anshuman Khandual <anshuman.khandual@arm.com>, Kees Cook <keescook@chromium.org> Subject: [PATCH v3 09/60] arm64: mm: Reclaim unused vmemmap region for vmalloc use Date: Tue, 7 Mar 2023 15:04:31 +0100 [thread overview] Message-ID: <20230307140522.2311461-10-ardb@kernel.org> (raw) In-Reply-To: <20230307140522.2311461-1-ardb@kernel.org> The vmemmap array is statically sized based on the maximum supported size of the virtual address space, but it is located inside the upper VA region, which is statically sized based on the *minimum* supported size of the VA space. This doesn't matter much when using 64k pages, which is the only configuration that currently supports 52-bit virtual addressing. However, upcoming LPA2 support will change this picture somewhat, as in that case, the vmemmap array will take up more than 25% of the upper VA region when using 4k pages. Given that most of this space is never used when running on a system that does not support 52-bit virtual addressing, let's reclaim the unused vmemmap area in that case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm64/include/asm/pgtable.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 3eff06c5d0eb73c7..2259898e8c3d990a 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -18,11 +18,15 @@ * VMALLOC range. * * VMALLOC_START: beginning of the kernel vmalloc space - * VMALLOC_END: extends to the available space below vmemmap, PCI I/O space - * and fixed mappings + * VMALLOC_END: extends to the available space below vmemmap */ #define VMALLOC_START (MODULES_END) +#if VA_BITS == VA_BITS_MIN #define VMALLOC_END (VMEMMAP_START - SZ_8M) +#else +#define VMEMMAP_UNUSED_NPAGES ((_PAGE_OFFSET(vabits_actual) - PAGE_OFFSET) >> PAGE_SHIFT) +#define VMALLOC_END (VMEMMAP_START + VMEMMAP_UNUSED_NPAGES * sizeof(struct page) - SZ_8M) +#endif #define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) -- 2.39.2
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org> To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel <ardb@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Ryan Roberts <ryan.roberts@arm.com>, Anshuman Khandual <anshuman.khandual@arm.com>, Kees Cook <keescook@chromium.org> Subject: [PATCH v3 09/60] arm64: mm: Reclaim unused vmemmap region for vmalloc use Date: Tue, 7 Mar 2023 15:04:31 +0100 [thread overview] Message-ID: <20230307140522.2311461-10-ardb@kernel.org> (raw) In-Reply-To: <20230307140522.2311461-1-ardb@kernel.org> The vmemmap array is statically sized based on the maximum supported size of the virtual address space, but it is located inside the upper VA region, which is statically sized based on the *minimum* supported size of the VA space. This doesn't matter much when using 64k pages, which is the only configuration that currently supports 52-bit virtual addressing. However, upcoming LPA2 support will change this picture somewhat, as in that case, the vmemmap array will take up more than 25% of the upper VA region when using 4k pages. Given that most of this space is never used when running on a system that does not support 52-bit virtual addressing, let's reclaim the unused vmemmap area in that case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm64/include/asm/pgtable.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 3eff06c5d0eb73c7..2259898e8c3d990a 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -18,11 +18,15 @@ * VMALLOC range. * * VMALLOC_START: beginning of the kernel vmalloc space - * VMALLOC_END: extends to the available space below vmemmap, PCI I/O space - * and fixed mappings + * VMALLOC_END: extends to the available space below vmemmap */ #define VMALLOC_START (MODULES_END) +#if VA_BITS == VA_BITS_MIN #define VMALLOC_END (VMEMMAP_START - SZ_8M) +#else +#define VMEMMAP_UNUSED_NPAGES ((_PAGE_OFFSET(vabits_actual) - PAGE_OFFSET) >> PAGE_SHIFT) +#define VMALLOC_END (VMEMMAP_START + VMEMMAP_UNUSED_NPAGES * sizeof(struct page) - SZ_8M) +#endif #define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-03-07 14:08 UTC|newest] Thread overview: 184+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-03-07 14:04 [PATCH v3 00/60] arm64: Add support for LPA2 at stage1 and WXN Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 01/60] arm64: kernel: Disable latent_entropy GCC plugin in early C runtime Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-28 10:37 ` Mark Rutland 2023-04-28 10:37 ` Mark Rutland 2023-04-28 10:54 ` Ard Biesheuvel 2023-04-28 10:54 ` Ard Biesheuvel 2023-04-28 11:48 ` Mark Rutland 2023-04-28 11:48 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 02/60] arm64: mm: Take potential load offset into account when KASLR is off Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-28 10:41 ` Mark Rutland 2023-04-28 10:41 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 03/60] arm64: mm: get rid of kimage_vaddr global variable Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-28 10:42 ` Mark Rutland 2023-04-28 10:42 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 04/60] arm64: mm: Move PCI I/O emulation region above the vmemmap region Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 05/60] arm64: mm: Move fixmap region above " Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-28 11:00 ` Mark Rutland 2023-04-28 11:00 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 06/60] arm64: ptdump: Allow VMALLOC_END to be defined at boot Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 16:58 ` Ryan Roberts 2023-03-07 16:58 ` Ryan Roberts 2023-03-07 17:01 ` Ard Biesheuvel 2023-03-07 17:01 ` Ard Biesheuvel 2023-04-28 11:25 ` Mark Rutland 2023-04-28 11:25 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 07/60] arm64: ptdump: Discover start of vmemmap region at runtime Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 16:36 ` Ryan Roberts 2023-03-07 16:36 ` Ryan Roberts 2023-04-28 11:27 ` Mark Rutland 2023-04-28 11:27 ` Mark Rutland 2023-03-07 14:04 ` [PATCH v3 08/60] arm64: vmemmap: Avoid base2 order of struct page size to dimension region Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel [this message] 2023-03-07 14:04 ` [PATCH v3 09/60] arm64: mm: Reclaim unused vmemmap region for vmalloc use Ard Biesheuvel 2023-03-07 16:42 ` Ryan Roberts 2023-03-07 16:42 ` Ryan Roberts 2023-03-07 16:58 ` Ard Biesheuvel 2023-03-07 16:58 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 10/60] arm64: kaslr: Adjust randomization range dynamically Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 11/60] arm64: kaslr: drop special case for ThunderX in kaslr_requires_kpti() Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 12/60] arm64: Turn kaslr_feature_override into a generic SW feature override Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 13/60] arm64: kvm: honour 'nokaslr' command line option for the HYP VA space Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 14/60] arm64: kernel: Manage absolute relocations in code built under pi/ Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 15/60] arm64: kernel: Don't rely on objcopy to make code under pi/ __init Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 16/60] arm64: head: move relocation handling to C code Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 17/60] arm64: idreg-override: Omit non-NULL checks for override pointer Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 18/60] arm64: idreg-override: Prepare for place relative reloc patching Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 19/60] arm64: idreg-override: Avoid parameq() and parameqn() Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 20/60] arm64: idreg-override: avoid strlen() to check for empty strings Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 21/60] arm64: idreg-override: Avoid sprintf() for simple string concatenation Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 22/60] arm64: idreg-override: Avoid kstrtou64() to parse a single hex digit Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 23/60] arm64: idreg-override: Move to early mini C runtime Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 24/60] arm64: kernel: Remove early fdt remap code Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 25/60] arm64: head: Clear BSS and the kernel page tables in one go Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-17 14:00 ` Ryan Roberts 2023-04-17 14:00 ` Ryan Roberts 2023-04-17 14:02 ` Ard Biesheuvel 2023-04-17 14:02 ` Ard Biesheuvel 2023-04-17 14:09 ` Ryan Roberts 2023-04-17 14:09 ` Ryan Roberts 2023-03-07 14:04 ` [PATCH v3 26/60] arm64: Move feature overrides into the BSS section Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 27/60] arm64: head: Run feature override detection before mapping the kernel Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 28/60] arm64: head: move dynamic shadow call stack patching into early C runtime Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 29/60] arm64: kaslr: Use feature override instead of parsing the cmdline again Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 30/60] arm64: idreg-override: Create a pseudo feature for rodata=off Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-17 14:28 ` Ryan Roberts 2023-04-17 14:28 ` Ryan Roberts 2023-04-17 14:30 ` Ard Biesheuvel 2023-04-17 14:30 ` Ard Biesheuvel 2023-04-17 14:33 ` Ryan Roberts 2023-04-17 14:33 ` Ryan Roberts 2023-03-07 14:04 ` [PATCH v3 31/60] arm64: Add helpers to probe local CPU for PAC/BTI/E0PD support Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 32/60] arm64: head: allocate more pages for the kernel mapping Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-17 15:48 ` Ryan Roberts 2023-04-17 15:48 ` Ryan Roberts 2023-04-17 16:11 ` Ard Biesheuvel 2023-04-17 16:11 ` Ard Biesheuvel 2023-04-17 16:18 ` Ryan Roberts 2023-04-17 16:18 ` Ryan Roberts 2023-03-07 14:04 ` [PATCH v3 33/60] arm64: head: move memstart_offset_seed handling to C code Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 34/60] arm64: head: Move early kernel mapping routines into " Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-18 9:31 ` Ryan Roberts 2023-04-18 9:31 ` Ryan Roberts 2023-04-18 10:06 ` Ard Biesheuvel 2023-04-18 10:06 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 35/60] arm64: mm: Use 48-bit virtual addressing for the permanent ID map Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-04-18 10:22 ` Ryan Roberts 2023-04-18 10:22 ` Ryan Roberts 2023-03-07 14:04 ` [PATCH v3 36/60] arm64: pgtable: Decouple PGDIR size macros from PGD/PUD/PMD levels Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:04 ` [PATCH v3 37/60] arm64: kernel: Create initial ID map from C code Ard Biesheuvel 2023-03-07 14:04 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 38/60] arm64: mm: avoid fixmap for early swapper_pg_dir updates Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 39/60] arm64: mm: omit redundant remap of kernel image Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 40/60] arm64: Revert "mm: provide idmap pointer to cpu_replace_ttbr1()" Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 41/60] arm64/mm: Add FEAT_LPA2 specific TCR_EL1.DS field Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 42/60] arm64/mm: Add FEAT_LPA2 specific ID_AA64MMFR0.TGRAN[2] Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 43/60] arm64: mm: Handle LVA support as a CPU feature Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 44/60] arm64: mm: Add feature override support for LVA Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 45/60] arm64: mm: Wire up TCR.DS bit to PTE shareability fields Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 46/60] arm64: mm: Add LPA2 support to phys<->pte conversion routines Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 47/60] arm64: mm: Add definitions to support 5 levels of paging Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 48/60] arm64: mm: add LPA2 and 5 level paging support to G-to-nG conversion Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 49/60] arm64: Enable LPA2 at boot if supported by the system Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-04-18 13:50 ` Ryan Roberts 2023-04-18 13:50 ` Ryan Roberts 2023-03-07 14:05 ` [PATCH v3 50/60] arm64: mm: Add 5 level paging support to fixmap and swapper handling Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 51/60] arm64: kasan: Reduce minimum shadow alignment and enable 5 level paging Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 52/60] arm64: mm: Add support for folding PUDs at runtime Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 53/60] arm64: ptdump: Disregard unaddressable VA space Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 54/60] arm64: ptdump: Deal with translation levels folded at runtime Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 55/60] arm64: kvm: avoid CONFIG_PGTABLE_LEVELS for runtime levels Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-04-18 14:29 ` Ryan Roberts 2023-04-18 14:29 ` Ryan Roberts 2023-03-07 14:05 ` [PATCH v3 56/60] arm64: kvm: Limit HYP VA and host S2 range to 48 bits when LPA2 is in effect Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-04-18 14:33 ` Ryan Roberts 2023-04-18 14:33 ` Ryan Roberts 2023-03-07 14:05 ` [PATCH v3 57/60] arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 58/60] arm64: defconfig: Enable LPA2 support Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 59/60] mm: add arch hook to validate mmap() prot flags Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 14:05 ` [PATCH v3 60/60] arm64: mm: add support for WXN memory translation attribute Ard Biesheuvel 2023-03-07 14:05 ` Ard Biesheuvel 2023-03-07 16:28 ` [PATCH v3 00/60] arm64: Add support for LPA2 at stage1 and WXN Ryan Roberts 2023-03-07 16:28 ` Ryan Roberts 2023-03-08 8:31 ` Ard Biesheuvel 2023-03-08 8:31 ` Ard Biesheuvel 2023-04-18 15:01 ` Ryan Roberts 2023-04-18 15:01 ` Ryan Roberts
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