From 5c8405d763dc2b125b39166bc70be1b8dcc80582 Mon Sep 17 00:00:00 2001 From: Stuart Menefy Date: Sun, 30 Jun 2024 12:05:49 +0100 Subject: [PATCH] riscv: Extend sv39 linear mapping max size to 128G This harmonizes all virtual addressing modes which can now all map (PGDIR_SIZE * PTRS_PER_PGD) / 4 of physical memory. The RISCV implementation of KASAN requires that the boundary between shallow mappings are aligned on an 8G boundary. In this case we need VMALLOC_START to be 8G aligned. So although we only need to move the start of the linear mapping down by 4GiB to allow 128GiB to be mapped, we actually move it down by 8GiB (creating a 4GiB hole between the linear mapping and KASAN shadow space) to maintain the alignment requirement. Signed-off-by: Stuart Menefy Reviewed-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20240630110550.1731929-1-stuart.menefy@codasip.com Signed-off-by: Palmer Dabbelt --- Documentation/arch/riscv/vm-layout.rst | 11 ++++++----- arch/riscv/include/asm/page.h | 2 +- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/Documentation/arch/riscv/vm-layout.rst b/Documentation/arch/riscv/vm-layout.rst index e476b4386bd9..077b968dcc81 100644 --- a/Documentation/arch/riscv/vm-layout.rst +++ b/Documentation/arch/riscv/vm-layout.rst @@ -47,11 +47,12 @@ RISC-V Linux Kernel SV39 | Kernel-space virtual memory, shared between all processes: ____________________________________________________________|___________________________________________________________ | | | | - ffffffc6fea00000 | -228 GB | ffffffc6feffffff | 6 MB | fixmap - ffffffc6ff000000 | -228 GB | ffffffc6ffffffff | 16 MB | PCI io - ffffffc700000000 | -228 GB | ffffffc7ffffffff | 4 GB | vmemmap - ffffffc800000000 | -224 GB | ffffffd7ffffffff | 64 GB | vmalloc/ioremap space - ffffffd800000000 | -160 GB | fffffff6ffffffff | 124 GB | direct mapping of all physical memory + ffffffc4fea00000 | -236 GB | ffffffc4feffffff | 6 MB | fixmap + ffffffc4ff000000 | -236 GB | ffffffc4ffffffff | 16 MB | PCI io + ffffffc500000000 | -236 GB | ffffffc5ffffffff | 4 GB | vmemmap + ffffffc600000000 | -232 GB | ffffffd5ffffffff | 64 GB | vmalloc/ioremap space + ffffffd600000000 | -168 GB | fffffff5ffffffff | 128 GB | direct mapping of all physical memory + | | | | fffffff700000000 | -36 GB | fffffffeffffffff | 32 GB | kasan __________________|____________|__________________|_________|____________________________________________________________ | diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 235fd45d998d..7ede2111c591 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -37,7 +37,7 @@ * define the PAGE_OFFSET value for SV48 and SV39. */ #define PAGE_OFFSET_L4 _AC(0xffffaf8000000000, UL) -#define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL) +#define PAGE_OFFSET_L3 _AC(0xffffffd600000000, UL) #else #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) #endif /* CONFIG_64BIT */