diff options
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 49 |
1 files changed, 40 insertions, 9 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 269fc648ef3d..7cb4f391d106 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -36,6 +36,9 @@ EXPORT_SYMBOL(kernel_map); #define kernel_map (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map)) #endif +phys_addr_t phys_ram_base __ro_after_init; +EXPORT_SYMBOL(phys_ram_base); + #ifdef CONFIG_XIP_KERNEL extern char _xiprom[], _exiprom[]; #endif @@ -127,10 +130,17 @@ void __init mem_init(void) } /* - * The default maximal physical memory size is -PAGE_OFFSET, - * limit the memory size via mem. + * The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel, + * whereas for 64-bit kernel, the end of the virtual address space is occupied + * by the modules/BPF/kernel mappings which reduces the available size of the + * linear mapping. + * Limit the memory size via mem. */ +#ifdef CONFIG_64BIT +static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G; +#else static phys_addr_t memory_limit = -PAGE_OFFSET; +#endif static int __init early_mem(char *p) { @@ -152,8 +162,8 @@ static void __init setup_bootmem(void) { phys_addr_t vmlinux_end = __pa_symbol(&_end); phys_addr_t vmlinux_start = __pa_symbol(&_start); - phys_addr_t max_mapped_addr = __pa(~(ulong)0); - phys_addr_t dram_end; + phys_addr_t __maybe_unused max_mapped_addr; + phys_addr_t phys_ram_end; #ifdef CONFIG_XIP_KERNEL vmlinux_start = __pa_symbol(&_sdata); @@ -174,18 +184,28 @@ static void __init setup_bootmem(void) #endif memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); - dram_end = memblock_end_of_DRAM(); + + phys_ram_end = memblock_end_of_DRAM(); +#ifndef CONFIG_64BIT +#ifndef CONFIG_XIP_KERNEL + phys_ram_base = memblock_start_of_DRAM(); +#endif /* * 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 * macro. Make sure that last 4k bytes are not usable by memblock - * if end of dram is equal to maximum addressable memory. + * if end of dram is equal to maximum addressable memory. For 64-bit + * kernel, this problem can't happen here as the end of the virtual + * address space is occupied by the kernel mapping then this check must + * be done as soon as the kernel mapping base address is determined. */ - if (max_mapped_addr == (dram_end - 1)) + max_mapped_addr = __pa(~(ulong)0); + if (max_mapped_addr == (phys_ram_end - 1)) memblock_set_current_limit(max_mapped_addr - 4096); +#endif - min_low_pfn = PFN_UP(memblock_start_of_DRAM()); - max_low_pfn = max_pfn = PFN_DOWN(dram_end); + min_low_pfn = PFN_UP(phys_ram_base); + max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end); dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn)); set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET); @@ -544,6 +564,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR; kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom); + phys_ram_base = CONFIG_PHYS_RAM_BASE; kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE; kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata); @@ -570,6 +591,14 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); BUG_ON((kernel_map.phys_addr % map_size) != 0); +#ifdef CONFIG_64BIT + /* + * The last 4K bytes of the addressable memory can not be mapped because + * of IS_ERR_VALUE macro. + */ + BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); +#endif + pt_ops.alloc_pte = alloc_pte_early; pt_ops.get_pte_virt = get_pte_virt_early; #ifndef __PAGETABLE_PMD_FOLDED @@ -709,6 +738,8 @@ static void __init setup_vm_final(void) 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; map_size = best_map_size(start, end - start); for (pa = start; pa < end; pa += map_size) { |