arch/arm/mm/copypage-xsc3.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/arch/arm/mm/copypage-xsc3.S
   4  *
   5  *  Copyright (C) 2004 Intel Corp.
   6  *
   7  * Adapted for 3rd gen XScale core, no more mini-dcache
   8  * Author: Matt Gilbert (matthew.m.gilbert@intel.com)
   9  */
  10 #include <linux/init.h>
  11 #include <linux/highmem.h>
  12
  13 /*
  14  * General note:
  15  *  We don't really want write-allocate cache behaviour for these functions
  16  *  since that will just eat through 8K of the cache.
  17  */
  18
  19 /*
  20  * XSC3 optimised copy_user_highpage
  21  *
  22  * The source page may have some clean entries in the cache already, but we
  23  * can safely ignore them - break_cow() will flush them out of the cache
  24  * if we eventually end up using our copied page.
  25  *
  26  */
  27 static void xsc3_mc_copy_user_page(void *kto, const void *kfrom)
  28 {
  29         int tmp;
  30
  31         asm volatile ("\
  32 .arch xscale                                    \n\
  33         pld     [%1, #0]                        \n\
  34         pld     [%1, #32]                       \n\
  35 1:      pld     [%1, #64]                       \n\
  36         pld     [%1, #96]                       \n\
  37                                                 \n\
  38 2:      ldrd    r2, r3, [%1], #8                \n\
  39         ldrd    r4, r5, [%1], #8                \n\
  40         mcr     p15, 0, %0, c7, c6, 1           @ invalidate\n\
  41         strd    r2, r3, [%0], #8                \n\
  42         ldrd    r2, r3, [%1], #8                \n\
  43         strd    r4, r5, [%0], #8                \n\
  44         ldrd    r4, r5, [%1], #8                \n\
  45         strd    r2, r3, [%0], #8                \n\
  46         strd    r4, r5, [%0], #8                \n\
  47         ldrd    r2, r3, [%1], #8                \n\
  48         ldrd    r4, r5, [%1], #8                \n\
  49         mcr     p15, 0, %0, c7, c6, 1           @ invalidate\n\
  50         strd    r2, r3, [%0], #8                \n\
  51         ldrd    r2, r3, [%1], #8                \n\
  52         subs    %2, %2, #1                      \n\
  53         strd    r4, r5, [%0], #8                \n\
  54         ldrd    r4, r5, [%1], #8                \n\
  55         strd    r2, r3, [%0], #8                \n\
  56         strd    r4, r5, [%0], #8                \n\
  57         bgt     1b                              \n\
  58         beq     2b                              "
  59         : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
  60         : "2" (PAGE_SIZE / 64 - 1)
  61         : "r2", "r3", "r4", "r5");
  62 }
  63
  64 void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
  65         unsigned long vaddr, struct vm_area_struct *vma)
  66 {
  67         void *kto, *kfrom;
  68
  69         kto = kmap_atomic(to);
  70         kfrom = kmap_atomic(from);
  71         flush_cache_page(vma, vaddr, page_to_pfn(from));
  72         xsc3_mc_copy_user_page(kto, kfrom);
  73         kunmap_atomic(kfrom);
  74         kunmap_atomic(kto);
  75 }
  76
  77 /*
  78  * XScale optimised clear_user_page
  79  */
  80 void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
  81 {
  82         void *ptr, *kaddr = kmap_atomic(page);
  83         asm volatile ("\
  84 .arch xscale                                    \n\
  85         mov     r1, %2                          \n\
  86         mov     r2, #0                          \n\
  87         mov     r3, #0                          \n\
  88 1:      mcr     p15, 0, %0, c7, c6, 1           @ invalidate line\n\
  89         strd    r2, r3, [%0], #8                \n\
  90         strd    r2, r3, [%0], #8                \n\
  91         strd    r2, r3, [%0], #8                \n\
  92         strd    r2, r3, [%0], #8                \n\
  93         subs    r1, r1, #1                      \n\
  94         bne     1b"
  95         : "=r" (ptr)
  96         : "0" (kaddr), "I" (PAGE_SIZE / 32)
  97         : "r1", "r2", "r3");
  98         kunmap_atomic(kaddr);
  99 }
 100
 101 struct cpu_user_fns xsc3_mc_user_fns __initdata = {
 102         .cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
 103         .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
 104 };