| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2020-2022 Loongson Technology Corporation Limited |
| */ |
| #include <linux/export.h> |
| #include <linux/mm.h> |
| #include <linux/mman.h> |
| |
| unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ |
| EXPORT_SYMBOL(shm_align_mask); |
| |
| #define COLOUR_ALIGN(addr, pgoff) \ |
| ((((addr) + shm_align_mask) & ~shm_align_mask) + \ |
| (((pgoff) << PAGE_SHIFT) & shm_align_mask)) |
| |
| enum mmap_allocation_direction {UP, DOWN}; |
| |
| static unsigned long arch_get_unmapped_area_common(struct file *filp, |
| unsigned long addr0, unsigned long len, unsigned long pgoff, |
| unsigned long flags, enum mmap_allocation_direction dir) |
| { |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| unsigned long addr = addr0; |
| int do_color_align; |
| struct vm_unmapped_area_info info; |
| |
| if (unlikely(len > TASK_SIZE)) |
| return -ENOMEM; |
| |
| if (flags & MAP_FIXED) { |
| /* Even MAP_FIXED mappings must reside within TASK_SIZE */ |
| if (TASK_SIZE - len < addr) |
| return -EINVAL; |
| |
| /* |
| * We do not accept a shared mapping if it would violate |
| * cache aliasing constraints. |
| */ |
| if ((flags & MAP_SHARED) && |
| ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) |
| return -EINVAL; |
| return addr; |
| } |
| |
| do_color_align = 0; |
| if (filp || (flags & MAP_SHARED)) |
| do_color_align = 1; |
| |
| /* requesting a specific address */ |
| if (addr) { |
| if (do_color_align) |
| addr = COLOUR_ALIGN(addr, pgoff); |
| else |
| addr = PAGE_ALIGN(addr); |
| |
| vma = find_vma(mm, addr); |
| if (TASK_SIZE - len >= addr && |
| (!vma || addr + len <= vm_start_gap(vma))) |
| return addr; |
| } |
| |
| info.length = len; |
| info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0; |
| info.align_offset = pgoff << PAGE_SHIFT; |
| |
| if (dir == DOWN) { |
| info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
| info.low_limit = PAGE_SIZE; |
| info.high_limit = mm->mmap_base; |
| addr = vm_unmapped_area(&info); |
| |
| if (!(addr & ~PAGE_MASK)) |
| return addr; |
| |
| /* |
| * A failed mmap() very likely causes application failure, |
| * so fall back to the bottom-up function here. This scenario |
| * can happen with large stack limits and large mmap() |
| * allocations. |
| */ |
| } |
| |
| info.flags = 0; |
| info.low_limit = mm->mmap_base; |
| info.high_limit = TASK_SIZE; |
| return vm_unmapped_area(&info); |
| } |
| |
| unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0, |
| unsigned long len, unsigned long pgoff, unsigned long flags) |
| { |
| return arch_get_unmapped_area_common(filp, |
| addr0, len, pgoff, flags, UP); |
| } |
| |
| /* |
| * There is no need to export this but sched.h declares the function as |
| * extern so making it static here results in an error. |
| */ |
| unsigned long arch_get_unmapped_area_topdown(struct file *filp, |
| unsigned long addr0, unsigned long len, unsigned long pgoff, |
| unsigned long flags) |
| { |
| return arch_get_unmapped_area_common(filp, |
| addr0, len, pgoff, flags, DOWN); |
| } |
| |
| int __virt_addr_valid(volatile void *kaddr) |
| { |
| unsigned long vaddr = (unsigned long)kaddr; |
| |
| if ((vaddr < PAGE_OFFSET) || (vaddr >= vm_map_base)) |
| return 0; |
| |
| return pfn_valid(PFN_DOWN(PHYSADDR(kaddr))); |
| } |
| EXPORT_SYMBOL_GPL(__virt_addr_valid); |