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         pld     [%1, #0]                        \n\
  33         pld     [%1, #32]                       \n\
  34 1:      pld     [%1, #64]                       \n\
  35         pld     [%1, #96]                       \n\
  36                                                 \n\
  37 2:      ldrd    r2, r3, [%1], #8                \n\
  38         ldrd    r4, r5, [%1], #8                \n\
  39         mcr     p15, 0, %0, c7, c6, 1           @ invalidate\n\
  40         strd    r2, r3, [%0], #8                \n\
  41         ldrd    r2, r3, [%1], #8                \n\
  42         strd    r4, r5, [%0], #8                \n\
  43         ldrd    r4, r5, [%1], #8                \n\
  44         strd    r2, r3, [%0], #8                \n\
  45         strd    r4, r5, [%0], #8                \n\
  46         ldrd    r2, r3, [%1], #8                \n\
  47         ldrd    r4, r5, [%1], #8                \n\
  48         mcr     p15, 0, %0, c7, c6, 1           @ invalidate\n\
  49         strd    r2, r3, [%0], #8                \n\
  50         ldrd    r2, r3, [%1], #8                \n\
  51         subs    %2, %2, #1                      \n\
  52         strd    r4, r5, [%0], #8                \n\
  53         ldrd    r4, r5, [%1], #8                \n\
  54         strd    r2, r3, [%0], #8                \n\
  55         strd    r4, r5, [%0], #8                \n\
  56         bgt     1b                              \n\
  57         beq     2b                              "
  58         : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
  59         : "2" (PAGE_SIZE / 64 - 1)
  60         : "r2", "r3", "r4", "r5");
  61 }
  62
  63 void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
  64         unsigned long vaddr, struct vm_area_struct *vma)
  65 {
  66         void *kto, *kfrom;
  67
  68         kto = kmap_atomic(to);
  69         kfrom = kmap_atomic(from);
  70         flush_cache_page(vma, vaddr, page_to_pfn(from));
  71         xsc3_mc_copy_user_page(kto, kfrom);
  72         kunmap_atomic(kfrom);
  73         kunmap_atomic(kto);
  74 }
  75
  76 /*
  77  * XScale optimised clear_user_page
  78  */
  79 void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
  80 {
  81         void *ptr, *kaddr = kmap_atomic(page);
  82         asm volatile ("\
  83         mov     r1, %2                          \n\
  84         mov     r2, #0                          \n\
  85         mov     r3, #0                          \n\
  86 1:      mcr     p15, 0, %0, c7, c6, 1           @ invalidate line\n\
  87         strd    r2, r3, [%0], #8                \n\
  88         strd    r2, r3, [%0], #8                \n\
  89         strd    r2, r3, [%0], #8                \n\
  90         strd    r2, r3, [%0], #8                \n\
  91         subs    r1, r1, #1                      \n\
  92         bne     1b"
  93         : "=r" (ptr)
  94         : "0" (kaddr), "I" (PAGE_SIZE / 32)
  95         : "r1", "r2", "r3");
  96         kunmap_atomic(kaddr);
  97 }
  98
  99 struct cpu_user_fns xsc3_mc_user_fns __initdata = {
 100         .cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
 101         .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
 102 };