1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #ifndef __UM_TLBFLUSH_H 7 #define __UM_TLBFLUSH_H 8 9 #include <linux/mm.h> 10 11 /* 12 * In UML, we need to sync the TLB over by using mmap/munmap/mprotect syscalls 13 * from the process handling the MM (which can be the kernel itself). 14 * 15 * To track updates, we can hook into set_ptes and flush_tlb_*. With set_ptes 16 * we catch all PTE transitions where memory that was unusable becomes usable. 17 * While with flush_tlb_* we can track any memory that becomes unusable and 18 * even if a higher layer of the page table was modified. 19 * 20 * So, we simply track updates using both methods and mark the memory area to 21 * be synced later on. The only special case is that flush_tlb_kern_* needs to 22 * be executed immediately as there is no good synchronization point in that 23 * case. In contrast, in the set_ptes case we can wait for the next kernel 24 * segfault before we do the synchornization. 25 * 26 * - flush_tlb_all() flushes all processes TLBs 27 * - flush_tlb_mm(mm) flushes the specified mm context TLB's 28 * - flush_tlb_page(vma, vmaddr) flushes one page 29 * - flush_tlb_range(vma, start, end) flushes a range of pages 30 * - flush_tlb_kernel_range(start, end) flushes a range of kernel pages 31 */ 32 33 extern int um_tlb_sync(struct mm_struct *mm); 34 35 extern void flush_tlb_all(void); 36 extern void flush_tlb_mm(struct mm_struct *mm); 37 38 static inline void flush_tlb_page(struct vm_area_struct *vma, 39 unsigned long address) 40 { 41 um_tlb_mark_sync(vma->vm_mm, address, address + PAGE_SIZE); 42 } 43 44 static inline void flush_tlb_range(struct vm_area_struct *vma, 45 unsigned long start, unsigned long end) 46 { 47 um_tlb_mark_sync(vma->vm_mm, start, end); 48 } 49 50 static inline void flush_tlb_kernel_range(unsigned long start, 51 unsigned long end) 52 { 53 um_tlb_mark_sync(&init_mm, start, end); 54 55 /* Kernel needs to be synced immediately */ 56 um_tlb_sync(&init_mm); 57 } 58 59 #endif 60