arm/mm/copypage-fa.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *  linux/arch/arm/lib/copypage-fa.S
0004  *
0005  *  Copyright (C) 2005 Faraday Corp.
0006  *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
0007  *
0008  * Based on copypage-v4wb.S:
0009  *  Copyright (C) 1995-1999 Russell King
0010  */
0011 #include <linux/init.h>
0012 #include <linux/highmem.h>
0013
0014 /*
0015  * Faraday optimised copy_user_page
0016  */
0017 static void fa_copy_user_page(void *kto, const void *kfrom)
0018 {
0019     int tmp;
0020
0021     asm volatile ("\
0022 1:  ldmia   %1!, {r3, r4, ip, lr}       @ 4\n\
0023     stmia   %0, {r3, r4, ip, lr}        @ 4\n\
0024     mcr p15, 0, %0, c7, c14, 1      @ 1   clean and invalidate D line\n\
0025     add %0, %0, #16         @ 1\n\
0026     ldmia   %1!, {r3, r4, ip, lr}       @ 4\n\
0027     stmia   %0, {r3, r4, ip, lr}        @ 4\n\
0028     mcr p15, 0, %0, c7, c14, 1      @ 1   clean and invalidate D line\n\
0029     add %0, %0, #16         @ 1\n\
0030     subs    %2, %2, #1          @ 1\n\
0031     bne 1b              @ 1\n\
0032     mcr p15, 0, %2, c7, c10, 4      @ 1   drain WB"
0033     : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
0034     : "2" (PAGE_SIZE / 32)
0035     : "r3", "r4", "ip", "lr");
0036 }
0037
0038 void fa_copy_user_highpage(struct page *to, struct page *from,
0039     unsigned long vaddr, struct vm_area_struct *vma)
0040 {
0041     void *kto, *kfrom;
0042
0043     kto = kmap_atomic(to);
0044     kfrom = kmap_atomic(from);
0045     fa_copy_user_page(kto, kfrom);
0046     kunmap_atomic(kfrom);
0047     kunmap_atomic(kto);
0048 }
0049
0050 /*
0051  * Faraday optimised clear_user_page
0052  *
0053  * Same story as above.
0054  */
0055 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
0056 {
0057     void *ptr, *kaddr = kmap_atomic(page);
0058     asm volatile("\
0059     mov r1, %2              @ 1\n\
0060     mov r2, #0              @ 1\n\
0061     mov r3, #0              @ 1\n\
0062     mov ip, #0              @ 1\n\
0063     mov lr, #0              @ 1\n\
0064 1:  stmia   %0, {r2, r3, ip, lr}        @ 4\n\
0065     mcr p15, 0, %0, c7, c14, 1      @ 1   clean and invalidate D line\n\
0066     add %0, %0, #16         @ 1\n\
0067     stmia   %0, {r2, r3, ip, lr}        @ 4\n\
0068     mcr p15, 0, %0, c7, c14, 1      @ 1   clean and invalidate D line\n\
0069     add %0, %0, #16         @ 1\n\
0070     subs    r1, r1, #1          @ 1\n\
0071     bne 1b              @ 1\n\
0072     mcr p15, 0, r1, c7, c10, 4      @ 1   drain WB"
0073     : "=r" (ptr)
0074     : "0" (kaddr), "I" (PAGE_SIZE / 32)
0075     : "r1", "r2", "r3", "ip", "lr");
0076     kunmap_atomic(kaddr);
0077 }
0078
0079 struct cpu_user_fns fa_user_fns __initdata = {
0080     .cpu_clear_user_highpage = fa_clear_user_highpage,
0081     .cpu_copy_user_highpage = fa_copy_user_highpage,
0082 };