arch/xtensa/include/asm/highmem.h

   1 /*
   2  * include/asm-xtensa/highmem.h
   3  *
   4  * This file is subject to the terms and conditions of the GNU General
   5  * Public License.  See the file "COPYING" in the main directory of
   6  * this archive for more details.
   7  *
   8  * Copyright (C) 2003 - 2005 Tensilica Inc.
   9  * Copyright (C) 2014 Cadence Design Systems Inc.
  10  */
  11
  12 #ifndef _XTENSA_HIGHMEM_H
  13 #define _XTENSA_HIGHMEM_H
  14
  15 #include <linux/wait.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/fixmap.h>
  18 #include <asm/kmap_types.h>
  19 #include <asm/pgtable.h>
  20
  21 #define PKMAP_BASE              ((FIXADDR_START - \
  22                                   (LAST_PKMAP + 1) * PAGE_SIZE) & PMD_MASK)
  23 #define LAST_PKMAP              (PTRS_PER_PTE * DCACHE_N_COLORS)
  24 #define LAST_PKMAP_MASK         (LAST_PKMAP - 1)
  25 #define PKMAP_NR(virt)          (((virt) - PKMAP_BASE) >> PAGE_SHIFT)
  26 #define PKMAP_ADDR(nr)          (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  27
  28 #define kmap_prot               PAGE_KERNEL_EXEC
  29
  30 #if DCACHE_WAY_SIZE > PAGE_SIZE
  31 #define get_pkmap_color get_pkmap_color
  32 static inline int get_pkmap_color(struct page *page)
  33 {
  34         return DCACHE_ALIAS(page_to_phys(page));
  35 }
  36
  37 extern unsigned int last_pkmap_nr_arr[];
  38
  39 static inline unsigned int get_next_pkmap_nr(unsigned int color)
  40 {
  41         last_pkmap_nr_arr[color] =
  42                 (last_pkmap_nr_arr[color] + DCACHE_N_COLORS) & LAST_PKMAP_MASK;
  43         return last_pkmap_nr_arr[color] + color;
  44 }
  45
  46 static inline int no_more_pkmaps(unsigned int pkmap_nr, unsigned int color)
  47 {
  48         return pkmap_nr < DCACHE_N_COLORS;
  49 }
  50
  51 static inline int get_pkmap_entries_count(unsigned int color)
  52 {
  53         return LAST_PKMAP / DCACHE_N_COLORS;
  54 }
  55
  56 extern wait_queue_head_t pkmap_map_wait_arr[];
  57
  58 static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
  59 {
  60         return pkmap_map_wait_arr + color;
  61 }
  62 #endif
  63
  64 extern pte_t *pkmap_page_table;
  65
  66 void *kmap_high(struct page *page);
  67 void kunmap_high(struct page *page);
  68
  69 static inline void *kmap(struct page *page)
  70 {
  71         /* Check if this memory layout is broken because PKMAP overlaps
  72          * page table.
  73          */
  74         BUILD_BUG_ON(PKMAP_BASE <
  75                      XCHAL_PAGE_TABLE_VADDR + XCHAL_PAGE_TABLE_SIZE);
  76         BUG_ON(in_interrupt());
  77         if (!PageHighMem(page))
  78                 return page_address(page);
  79         return kmap_high(page);
  80 }
  81
  82 static inline void kunmap(struct page *page)
  83 {
  84         BUG_ON(in_interrupt());
  85         if (!PageHighMem(page))
  86                 return;
  87         kunmap_high(page);
  88 }
  89
  90 static inline void flush_cache_kmaps(void)
  91 {
  92         flush_cache_all();
  93 }
  94
  95 void *kmap_atomic(struct page *page);
  96 void __kunmap_atomic(void *kvaddr);
  97
  98 void kmap_init(void);
  99
 100 #endif