18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only 28c2ecf20Sopenharmony_ci/* 38c2ecf20Sopenharmony_ci * linux/arch/arm/mm/copypage-v4wt.S 48c2ecf20Sopenharmony_ci * 58c2ecf20Sopenharmony_ci * Copyright (C) 1995-1999 Russell King 68c2ecf20Sopenharmony_ci * 78c2ecf20Sopenharmony_ci * This is for CPUs with a writethrough cache and 'flush ID cache' is 88c2ecf20Sopenharmony_ci * the only supported cache operation. 98c2ecf20Sopenharmony_ci */ 108c2ecf20Sopenharmony_ci#include <linux/init.h> 118c2ecf20Sopenharmony_ci#include <linux/highmem.h> 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ci/* 148c2ecf20Sopenharmony_ci * ARMv4 optimised copy_user_highpage 158c2ecf20Sopenharmony_ci * 168c2ecf20Sopenharmony_ci * Since we have writethrough caches, we don't have to worry about 178c2ecf20Sopenharmony_ci * dirty data in the cache. However, we do have to ensure that 188c2ecf20Sopenharmony_ci * subsequent reads are up to date. 198c2ecf20Sopenharmony_ci */ 208c2ecf20Sopenharmony_cistatic void v4wt_copy_user_page(void *kto, const void *kfrom) 218c2ecf20Sopenharmony_ci{ 228c2ecf20Sopenharmony_ci int tmp; 238c2ecf20Sopenharmony_ci 248c2ecf20Sopenharmony_ci asm volatile ("\ 258c2ecf20Sopenharmony_ci .syntax unified\n\ 268c2ecf20Sopenharmony_ci ldmia %1!, {r3, r4, ip, lr} @ 4\n\ 278c2ecf20Sopenharmony_ci1: stmia %0!, {r3, r4, ip, lr} @ 4\n\ 288c2ecf20Sopenharmony_ci ldmia %1!, {r3, r4, ip, lr} @ 4+1\n\ 298c2ecf20Sopenharmony_ci stmia %0!, {r3, r4, ip, lr} @ 4\n\ 308c2ecf20Sopenharmony_ci ldmia %1!, {r3, r4, ip, lr} @ 4\n\ 318c2ecf20Sopenharmony_ci stmia %0!, {r3, r4, ip, lr} @ 4\n\ 328c2ecf20Sopenharmony_ci ldmia %1!, {r3, r4, ip, lr} @ 4\n\ 338c2ecf20Sopenharmony_ci subs %2, %2, #1 @ 1\n\ 348c2ecf20Sopenharmony_ci stmia %0!, {r3, r4, ip, lr} @ 4\n\ 358c2ecf20Sopenharmony_ci ldmiane %1!, {r3, r4, ip, lr} @ 4\n\ 368c2ecf20Sopenharmony_ci bne 1b @ 1\n\ 378c2ecf20Sopenharmony_ci mcr p15, 0, %2, c7, c7, 0 @ flush ID cache" 388c2ecf20Sopenharmony_ci : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp) 398c2ecf20Sopenharmony_ci : "2" (PAGE_SIZE / 64) 408c2ecf20Sopenharmony_ci : "r3", "r4", "ip", "lr"); 418c2ecf20Sopenharmony_ci} 428c2ecf20Sopenharmony_ci 438c2ecf20Sopenharmony_civoid v4wt_copy_user_highpage(struct page *to, struct page *from, 448c2ecf20Sopenharmony_ci unsigned long vaddr, struct vm_area_struct *vma) 458c2ecf20Sopenharmony_ci{ 468c2ecf20Sopenharmony_ci void *kto, *kfrom; 478c2ecf20Sopenharmony_ci 488c2ecf20Sopenharmony_ci kto = kmap_atomic(to); 498c2ecf20Sopenharmony_ci kfrom = kmap_atomic(from); 508c2ecf20Sopenharmony_ci v4wt_copy_user_page(kto, kfrom); 518c2ecf20Sopenharmony_ci kunmap_atomic(kfrom); 528c2ecf20Sopenharmony_ci kunmap_atomic(kto); 538c2ecf20Sopenharmony_ci} 548c2ecf20Sopenharmony_ci 558c2ecf20Sopenharmony_ci/* 568c2ecf20Sopenharmony_ci * ARMv4 optimised clear_user_page 578c2ecf20Sopenharmony_ci * 588c2ecf20Sopenharmony_ci * Same story as above. 598c2ecf20Sopenharmony_ci */ 608c2ecf20Sopenharmony_civoid v4wt_clear_user_highpage(struct page *page, unsigned long vaddr) 618c2ecf20Sopenharmony_ci{ 628c2ecf20Sopenharmony_ci void *ptr, *kaddr = kmap_atomic(page); 638c2ecf20Sopenharmony_ci asm volatile("\ 648c2ecf20Sopenharmony_ci mov r1, %2 @ 1\n\ 658c2ecf20Sopenharmony_ci mov r2, #0 @ 1\n\ 668c2ecf20Sopenharmony_ci mov r3, #0 @ 1\n\ 678c2ecf20Sopenharmony_ci mov ip, #0 @ 1\n\ 688c2ecf20Sopenharmony_ci mov lr, #0 @ 1\n\ 698c2ecf20Sopenharmony_ci1: stmia %0!, {r2, r3, ip, lr} @ 4\n\ 708c2ecf20Sopenharmony_ci stmia %0!, {r2, r3, ip, lr} @ 4\n\ 718c2ecf20Sopenharmony_ci stmia %0!, {r2, r3, ip, lr} @ 4\n\ 728c2ecf20Sopenharmony_ci stmia %0!, {r2, r3, ip, lr} @ 4\n\ 738c2ecf20Sopenharmony_ci subs r1, r1, #1 @ 1\n\ 748c2ecf20Sopenharmony_ci bne 1b @ 1\n\ 758c2ecf20Sopenharmony_ci mcr p15, 0, r2, c7, c7, 0 @ flush ID cache" 768c2ecf20Sopenharmony_ci : "=r" (ptr) 778c2ecf20Sopenharmony_ci : "0" (kaddr), "I" (PAGE_SIZE / 64) 788c2ecf20Sopenharmony_ci : "r1", "r2", "r3", "ip", "lr"); 798c2ecf20Sopenharmony_ci kunmap_atomic(kaddr); 808c2ecf20Sopenharmony_ci} 818c2ecf20Sopenharmony_ci 828c2ecf20Sopenharmony_cistruct cpu_user_fns v4wt_user_fns __initdata = { 838c2ecf20Sopenharmony_ci .cpu_clear_user_highpage = v4wt_clear_user_highpage, 848c2ecf20Sopenharmony_ci .cpu_copy_user_highpage = v4wt_copy_user_highpage, 858c2ecf20Sopenharmony_ci}; 86