diff options
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 58 |
1 files changed, 52 insertions, 6 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index ed07ae111f3a..7bd66795165d 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -213,6 +213,14 @@ static void __init setup_bootmem(void) phys_ram_end = memblock_end_of_DRAM(); if (!IS_ENABLED(CONFIG_XIP_KERNEL)) phys_ram_base = memblock_start_of_DRAM(); + + /* + * In 64-bit, any use of __va/__pa before this point is wrong as we + * did not know the start of DRAM before. + */ + if (IS_ENABLED(CONFIG_64BIT)) + kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base; + /* * memblock allocator is not aware of the fact that last 4K bytes of * the addressable memory can not be mapped because of IS_ERR_VALUE @@ -667,9 +675,16 @@ void __init create_pgd_mapping(pgd_t *pgdp, static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) { - /* Upgrade to PMD_SIZE mappings whenever possible */ - base &= PMD_SIZE - 1; - if (!base && size >= PMD_SIZE) + if (!(base & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE) + return PGDIR_SIZE; + + if (!(base & (P4D_SIZE - 1)) && size >= P4D_SIZE) + return P4D_SIZE; + + if (!(base & (PUD_SIZE - 1)) && size >= PUD_SIZE) + return PUD_SIZE; + + if (!(base & (PMD_SIZE - 1)) && size >= PMD_SIZE) return PMD_SIZE; return PAGE_SIZE; @@ -978,11 +993,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) set_satp_mode(); #endif - kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr; + /* + * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem, + * where we have the system memory layout: this allows us to align + * the physical and virtual mappings and then make use of PUD/P4D/PGD + * for the linear mapping. This is only possible because the kernel + * mapping lies outside the linear mapping. + * In 32-bit however, as the kernel resides in the linear mapping, + * setup_vm_final can not change the mapping established here, + * otherwise the same kernel addresses would get mapped to different + * physical addresses (if the start of dram is different from the + * kernel physical address start). + */ + kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ? + 0UL : PAGE_OFFSET - kernel_map.phys_addr; kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr; - phys_ram_base = kernel_map.phys_addr; - /* * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit * kernel, whereas for 64-bit kernel, the end of the virtual address @@ -1106,6 +1132,17 @@ static void __init create_linear_mapping_page_table(void) phys_addr_t start, end; u64 i; +#ifdef CONFIG_STRICT_KERNEL_RWX + phys_addr_t ktext_start = __pa_symbol(_start); + phys_addr_t ktext_size = __init_data_begin - _start; + phys_addr_t krodata_start = __pa_symbol(__start_rodata); + phys_addr_t krodata_size = _data - __start_rodata; + + /* Isolate kernel text and rodata so they don't get mapped with a PUD */ + memblock_mark_nomap(ktext_start, ktext_size); + memblock_mark_nomap(krodata_start, krodata_size); +#endif + /* Map all memory banks in the linear mapping */ for_each_mem_range(i, &start, &end) { if (start >= end) @@ -1118,6 +1155,15 @@ static void __init create_linear_mapping_page_table(void) create_linear_mapping_range(start, end); } + +#ifdef CONFIG_STRICT_KERNEL_RWX + create_linear_mapping_range(ktext_start, ktext_start + ktext_size); + create_linear_mapping_range(krodata_start, + krodata_start + krodata_size); + + memblock_clear_nomap(ktext_start, ktext_size); + memblock_clear_nomap(krodata_start, krodata_size); +#endif } static void __init setup_vm_final(void) |