diff options
| author | Samuel Holland <samuel.holland@sifive.com> | 2024-10-26 20:13:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-04 15:41:54 +0300 |
| commit | bbf3bb6ddea47f6270224308eaa9d8b8ff72062f (patch) | |
| tree | c5ac4c1f64781343477cf7a5c23e94d03d7420d7 /arch/riscv/include | |
| parent | 09096ead92f39292267ab10113e4c7df4b9ed3f7 (diff) | |
| download | linux-bbf3bb6ddea47f6270224308eaa9d8b8ff72062f.tar.xz | |
riscv: Allow NOMMU kernels to access all of RAM
[ Upstream commit 2c0391b29b27f315c1b4c29ffde66f50b29fab99 ]
NOMMU kernels currently cannot access memory below the kernel link
address. Remove this restriction by setting PAGE_OFFSET to the actual
start of RAM, as determined from the devicetree. The kernel link address
must be a constant, so keep using CONFIG_PAGE_OFFSET for that purpose.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Jesse Taube <mr.bossman075@gmail.com>
Link: https://lore.kernel.org/r/20241026171441.3047904-3-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/riscv/include')
| -rw-r--r-- | arch/riscv/include/asm/page.h | 12 | ||||
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 2 |
2 files changed, 5 insertions, 9 deletions
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 4d1f58848129..dbb9d0d0f405 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -26,12 +26,9 @@ * When not using MMU this corresponds to the first free page in * physical memory (aligned on a page boundary). */ -#ifdef CONFIG_64BIT #ifdef CONFIG_MMU +#ifdef CONFIG_64BIT #define PAGE_OFFSET kernel_map.page_offset -#else -#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) -#endif /* * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so * define the PAGE_OFFSET value for SV48 and SV39. @@ -41,6 +38,9 @@ #else #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) #endif /* CONFIG_64BIT */ +#else +#define PAGE_OFFSET ((unsigned long)phys_ram_base) +#endif /* CONFIG_MMU */ #ifndef __ASSEMBLY__ @@ -97,11 +97,7 @@ typedef struct page *pgtable_t; #define MIN_MEMBLOCK_ADDR 0 #endif -#ifdef CONFIG_MMU #define ARCH_PFN_OFFSET (PFN_DOWN((unsigned long)phys_ram_base)) -#else -#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) -#endif /* CONFIG_MMU */ struct kernel_mapping { unsigned long page_offset; diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index f540b2625714..332a6bf72b1d 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -12,7 +12,7 @@ #include <asm/pgtable-bits.h> #ifndef CONFIG_MMU -#define KERNEL_LINK_ADDR PAGE_OFFSET +#define KERNEL_LINK_ADDR _AC(CONFIG_PAGE_OFFSET, UL) #define KERN_VIRT_SIZE (UL(-1)) #else |