LXR linux/arch/nds32/include/asm/highmem.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2// Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4#ifndef _ASM_HIGHMEM_H
   5#define _ASM_HIGHMEM_H
   6
   7#include <asm/proc-fns.h>
   8#include <asm/fixmap.h>
   9
  10/*
  11 * Right now we initialize only a single pte table. It can be extended
  12 * easily, subsequent pte tables have to be allocated in one physical
  13 * chunk of RAM.
  14 */
  15/*
  16 * Ordering is (from lower to higher memory addresses):
  17 *
  18 * high_memory
  19 *                      Persistent kmap area
  20 * PKMAP_BASE
  21 *                      fixed_addresses
  22 * FIXADDR_START
  23 * FIXADDR_TOP
  24 *                      Vmalloc area
  25 * VMALLOC_START
  26 * VMALLOC_END
  27 */
  28#define PKMAP_BASE              ((FIXADDR_START - PGDIR_SIZE) & (PGDIR_MASK))
  29#define LAST_PKMAP              PTRS_PER_PTE
  30#define LAST_PKMAP_MASK         (LAST_PKMAP - 1)
  31#define PKMAP_NR(virt)          (((virt) - (PKMAP_BASE)) >> PAGE_SHIFT)
  32#define PKMAP_ADDR(nr)          (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  33
  34static inline void flush_cache_kmaps(void)
  35{
  36        cpu_dcache_wbinval_all();
  37}
  38
  39/* declarations for highmem.c */
  40extern unsigned long highstart_pfn, highend_pfn;
  41
  42extern pte_t *pkmap_page_table;
  43
  44extern void kmap_init(void);
  45
  46/*
  47 * FIXME: The below looks broken vs. a kmap_atomic() in task context which
  48 * is interupted and another kmap_atomic() happens in interrupt context.
  49 * But what do I know about nds32. -- tglx
  50 */
  51#define arch_kmap_local_post_map(vaddr, pteval)                 \
  52        do {                                                    \
  53                __nds32__tlbop_inv(vaddr);                      \
  54                __nds32__mtsr_dsb(vaddr, NDS32_SR_TLB_VPN);     \
  55                __nds32__tlbop_rwr(pteval);                     \
  56                __nds32__isb();                                 \
  57        } while (0)
  58
  59#define arch_kmap_local_pre_unmap(vaddr)                        \
  60        do {                                                    \
  61                __nds32__tlbop_inv(vaddr);                      \
  62                __nds32__isb();                                 \
  63        } while (0)
  64
  65#endif
  66