diff options
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 206 |
1 files changed, 169 insertions, 37 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 0f14f4a8d179..a39fe42baf55 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -20,6 +20,9 @@ #include <linux/dma-map-ops.h> #include <linux/crash_dump.h> #include <linux/hugetlb.h> +#ifdef CONFIG_RELOCATABLE +#include <linux/elf.h> +#endif #include <asm/fixmap.h> #include <asm/tlbflush.h> @@ -145,7 +148,7 @@ static void __init print_vm_layout(void) print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END); #endif - print_ml("kernel", (unsigned long)KERNEL_LINK_ADDR, + print_ml("kernel", (unsigned long)kernel_map.virt_addr, (unsigned long)ADDRESS_SPACE_END); } } @@ -212,6 +215,14 @@ 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 @@ -261,9 +272,6 @@ static void __init setup_bootmem(void) #ifdef CONFIG_MMU struct pt_alloc_ops pt_ops __initdata; -unsigned long riscv_pfn_base __ro_after_init; -EXPORT_SYMBOL(riscv_pfn_base); - pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; @@ -272,7 +280,6 @@ pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); #ifdef CONFIG_XIP_KERNEL #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops)) -#define riscv_pfn_base (*(unsigned long *)XIP_FIXUP(&riscv_pfn_base)) #define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir)) #define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte)) #define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir)) @@ -654,9 +661,16 @@ 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; @@ -715,6 +729,8 @@ static __init pgprot_t pgprot_from_va(uintptr_t va) #endif /* CONFIG_STRICT_KERNEL_RWX */ #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) +u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa); + static void __init disable_pgtable_l5(void) { pgtable_l5_enabled = false; @@ -729,17 +745,39 @@ static void __init disable_pgtable_l4(void) satp_mode = SATP_MODE_39; } +static int __init print_no4lvl(char *p) +{ + pr_info("Disabled 4-level and 5-level paging"); + return 0; +} +early_param("no4lvl", print_no4lvl); + +static int __init print_no5lvl(char *p) +{ + pr_info("Disabled 5-level paging"); + return 0; +} +early_param("no5lvl", print_no5lvl); + /* * There is a simple way to determine if 4-level is supported by the * underlying hardware: establish 1:1 mapping in 4-level page table mode * then read SATP to see if the configuration was taken into account * meaning sv48 is supported. */ -static __init void set_satp_mode(void) +static __init void set_satp_mode(uintptr_t dtb_pa) { u64 identity_satp, hw_satp; uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; - bool check_l4 = false; + u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa); + + if (satp_mode_cmdline == SATP_MODE_57) { + disable_pgtable_l5(); + } else if (satp_mode_cmdline == SATP_MODE_48) { + disable_pgtable_l5(); + disable_pgtable_l4(); + return; + } create_p4d_mapping(early_p4d, set_satp_mode_pmd, (uintptr_t)early_pud, @@ -758,7 +796,8 @@ static __init void set_satp_mode(void) retry: create_pgd_mapping(early_pg_dir, set_satp_mode_pmd, - check_l4 ? (uintptr_t)early_pud : (uintptr_t)early_p4d, + pgtable_l5_enabled ? + (uintptr_t)early_p4d : (uintptr_t)early_pud, PGDIR_SIZE, PAGE_TABLE); identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode; @@ -769,9 +808,8 @@ retry: local_flush_tlb_all(); if (hw_satp != identity_satp) { - if (!check_l4) { + if (pgtable_l5_enabled) { disable_pgtable_l5(); - check_l4 = true; memset(early_pg_dir, 0, PAGE_SIZE); goto retry; } @@ -803,6 +841,44 @@ retry: #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." #endif +#ifdef CONFIG_RELOCATABLE +extern unsigned long __rela_dyn_start, __rela_dyn_end; + +static void __init relocate_kernel(void) +{ + Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start; + /* + * This holds the offset between the linked virtual address and the + * relocated virtual address. + */ + uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR; + /* + * This holds the offset between kernel linked virtual address and + * physical address. + */ + uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr; + + for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) { + Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset); + Elf64_Addr relocated_addr = rela->r_addend; + + if (rela->r_info != R_RISCV_RELATIVE) + continue; + + /* + * Make sure to not relocate vdso symbols like rt_sigreturn + * which are linked from the address 0 in vmlinux since + * vdso symbol addresses are actually used as an offset from + * mm->context.vdso in VDSO_OFFSET macro. + */ + if (relocated_addr >= KERNEL_LINK_ADDR) + relocated_addr += reloc_offset; + + *(Elf64_Addr *)addr = relocated_addr; + } +} +#endif /* CONFIG_RELOCATABLE */ + #ifdef CONFIG_XIP_KERNEL static void __init create_kernel_page_table(pgd_t *pgdir, __always_unused bool early) @@ -958,14 +1034,25 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #endif #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) - set_satp_mode(); + set_satp_mode(dtb_pa); #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; - riscv_pfn_base = PFN_DOWN(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 @@ -986,6 +1073,17 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); #endif +#ifdef CONFIG_RELOCATABLE + /* + * Early page table uses only one PUD, which makes it possible + * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset + * makes the kernel cross over a PUD_SIZE boundary, raise a bug + * since a part of the kernel would not get mapped. + */ + BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size); + relocate_kernel(); +#endif + apply_early_boot_alternatives(); pt_ops_set_early(); @@ -1070,12 +1168,62 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) pt_ops_set_fixmap(); } -static void __init setup_vm_final(void) +static void __init create_linear_mapping_range(phys_addr_t start, + phys_addr_t end) { + phys_addr_t pa; uintptr_t va, map_size; - phys_addr_t pa, start, end; + + for (pa = start; pa < end; pa += map_size) { + va = (uintptr_t)__va(pa); + map_size = best_map_size(pa, end - pa); + + create_pgd_mapping(swapper_pg_dir, va, pa, map_size, + pgprot_from_va(va)); + } +} + +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) + break; + if (start <= __pa(PAGE_OFFSET) && + __pa(PAGE_OFFSET) < end) + start = __pa(PAGE_OFFSET); + if (end >= __pa(PAGE_OFFSET) + memory_limit) + end = __pa(PAGE_OFFSET) + memory_limit; + + 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) +{ /* Setup swapper PGD for fixmap */ #if !defined(CONFIG_64BIT) /* @@ -1091,24 +1239,8 @@ static void __init setup_vm_final(void) __pa_symbol(fixmap_pgd_next), PGDIR_SIZE, PAGE_TABLE); - /* Map all memory banks in the linear mapping */ - for_each_mem_range(i, &start, &end) { - if (start >= end) - break; - if (start <= __pa(PAGE_OFFSET) && - __pa(PAGE_OFFSET) < end) - start = __pa(PAGE_OFFSET); - if (end >= __pa(PAGE_OFFSET) + memory_limit) - end = __pa(PAGE_OFFSET) + memory_limit; - - for (pa = start; pa < end; pa += map_size) { - va = (uintptr_t)__va(pa); - map_size = best_map_size(pa, end - pa); - - create_pgd_mapping(swapper_pg_dir, va, pa, map_size, - pgprot_from_va(va)); - } - } + /* Map the linear mapping */ + create_linear_mapping_page_table(); /* Map the kernel */ if (IS_ENABLED(CONFIG_64BIT)) |