arch/loongarch/include/asm/vdso/vdso.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Author: Huacai Chen <chenhuacai@loongson.cn>
   4  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
   5  */
   6
   7 #ifndef __ASSEMBLY__
   8
   9 #include <asm/asm.h>
  10 #include <asm/page.h>
  11 #include <asm/vdso.h>
  12
  13 struct vdso_pcpu_data {
  14         u32 node;
  15 } ____cacheline_aligned_in_smp;
  16
  17 struct loongarch_vdso_data {
  18         struct vdso_pcpu_data pdata[NR_CPUS];
  19 };
  20
  21 /*
  22  * The layout of vvar:
  23  *
  24  *                      high
  25  * +---------------------+--------------------------+
  26  * | loongarch vdso data | LOONGARCH_VDSO_DATA_SIZE |
  27  * +---------------------+--------------------------+
  28  * |  time-ns vdso data  |        PAGE_SIZE         |
  29  * +---------------------+--------------------------+
  30  * |  generic vdso data  |        PAGE_SIZE         |
  31  * +---------------------+--------------------------+
  32  *                      low
  33  */
  34 #define LOONGARCH_VDSO_DATA_SIZE PAGE_ALIGN(sizeof(struct loongarch_vdso_data))
  35 #define LOONGARCH_VDSO_DATA_PAGES (LOONGARCH_VDSO_DATA_SIZE >> PAGE_SHIFT)
  36
  37 enum vvar_pages {
  38         VVAR_GENERIC_PAGE_OFFSET,
  39         VVAR_TIMENS_PAGE_OFFSET,
  40         VVAR_LOONGARCH_PAGES_START,
  41         VVAR_LOONGARCH_PAGES_END = VVAR_LOONGARCH_PAGES_START + LOONGARCH_VDSO_DATA_PAGES - 1,
  42         VVAR_NR_PAGES,
  43 };
  44
  45 #define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
  46
  47 static inline unsigned long get_vdso_base(void)
  48 {
  49         unsigned long addr;
  50
  51         __asm__(
  52         " la.pcrel %0, _start\n"
  53         : "=r" (addr)
  54         :
  55         :);
  56
  57         return addr;
  58 }
  59
  60 static inline unsigned long get_vdso_data(void)
  61 {
  62         return get_vdso_base() - VVAR_SIZE;
  63 }
  64
  65 #endif /* __ASSEMBLY__ */