arch/csky/include/asm/highmem.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #ifndef __ASM_CSKY_HIGHMEM_H
   5 #define __ASM_CSKY_HIGHMEM_H
   6
   7 #ifdef __KERNEL__
   8
   9 #include <linux/init.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/uaccess.h>
  12 #include <asm/kmap_types.h>
  13 #include <asm/cache.h>
  14
  15 /* undef for production */
  16 #define HIGHMEM_DEBUG 1
  17
  18 /* declarations for highmem.c */
  19 extern unsigned long highstart_pfn, highend_pfn;
  20
  21 extern pte_t *pkmap_page_table;
  22
  23 /*
  24  * Right now we initialize only a single pte table. It can be extended
  25  * easily, subsequent pte tables have to be allocated in one physical
  26  * chunk of RAM.
  27  */
  28 #define LAST_PKMAP 1024
  29 #define LAST_PKMAP_MASK (LAST_PKMAP-1)
  30 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
  31 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  32
  33 extern void *kmap_high(struct page *page);
  34 extern void kunmap_high(struct page *page);
  35
  36 extern void *kmap(struct page *page);
  37 extern void kunmap(struct page *page);
  38 extern void *kmap_atomic(struct page *page);
  39 extern void __kunmap_atomic(void *kvaddr);
  40 extern void *kmap_atomic_pfn(unsigned long pfn);
  41 extern struct page *kmap_atomic_to_page(void *ptr);
  42
  43 #define flush_cache_kmaps() do {} while (0)
  44
  45 extern void kmap_init(void);
  46
  47 #define kmap_prot PAGE_KERNEL
  48
  49 #endif /* __KERNEL__ */
  50
  51 #endif /* __ASM_CSKY_HIGHMEM_H */