arch/arm/mm/copypage-fa.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/arch/arm/lib/copypage-fa.S
   4  *
   5  *  Copyright (C) 2005 Faraday Corp.
   6  *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   7  *
   8  * Based on copypage-v4wb.S:
   9  *  Copyright (C) 1995-1999 Russell King
  10  */
  11 #include <linux/init.h>
  12 #include <linux/highmem.h>
  13
  14 /*
  15  * Faraday optimised copy_user_page
  16  */
  17 static void fa_copy_user_page(void *kto, const void *kfrom)
  18 {
  19         int tmp;
  20
  21         asm volatile ("\
  22 1:      ldmia   %1!, {r3, r4, ip, lr}           @ 4\n\
  23         stmia   %0, {r3, r4, ip, lr}            @ 4\n\
  24         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  25         add     %0, %0, #16                     @ 1\n\
  26         ldmia   %1!, {r3, r4, ip, lr}           @ 4\n\
  27         stmia   %0, {r3, r4, ip, lr}            @ 4\n\
  28         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  29         add     %0, %0, #16                     @ 1\n\
  30         subs    %2, %2, #1                      @ 1\n\
  31         bne     1b                              @ 1\n\
  32         mcr     p15, 0, %2, c7, c10, 4          @ 1   drain WB"
  33         : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
  34         : "2" (PAGE_SIZE / 32)
  35         : "r3", "r4", "ip", "lr");
  36 }
  37
  38 void fa_copy_user_highpage(struct page *to, struct page *from,
  39         unsigned long vaddr, struct vm_area_struct *vma)
  40 {
  41         void *kto, *kfrom;
  42
  43         kto = kmap_atomic(to);
  44         kfrom = kmap_atomic(from);
  45         fa_copy_user_page(kto, kfrom);
  46         kunmap_atomic(kfrom);
  47         kunmap_atomic(kto);
  48 }
  49
  50 /*
  51  * Faraday optimised clear_user_page
  52  *
  53  * Same story as above.
  54  */
  55 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
  56 {
  57         void *ptr, *kaddr = kmap_atomic(page);
  58         asm volatile("\
  59         mov     r1, %2                          @ 1\n\
  60         mov     r2, #0                          @ 1\n\
  61         mov     r3, #0                          @ 1\n\
  62         mov     ip, #0                          @ 1\n\
  63         mov     lr, #0                          @ 1\n\
  64 1:      stmia   %0, {r2, r3, ip, lr}            @ 4\n\
  65         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  66         add     %0, %0, #16                     @ 1\n\
  67         stmia   %0, {r2, r3, ip, lr}            @ 4\n\
  68         mcr     p15, 0, %0, c7, c14, 1          @ 1   clean and invalidate D line\n\
  69         add     %0, %0, #16                     @ 1\n\
  70         subs    r1, r1, #1                      @ 1\n\
  71         bne     1b                              @ 1\n\
  72         mcr     p15, 0, r1, c7, c10, 4          @ 1   drain WB"
  73         : "=r" (ptr)
  74         : "0" (kaddr), "I" (PAGE_SIZE / 32)
  75         : "r1", "r2", "r3", "ip", "lr");
  76         kunmap_atomic(kaddr);
  77 }
  78
  79 struct cpu_user_fns fa_user_fns __initdata = {
  80         .cpu_clear_user_highpage = fa_clear_user_highpage,
  81         .cpu_copy_user_highpage = fa_copy_user_highpage,
  82 };