cp/include/page.h

   1 /*
   2  * (C) Copyright 2007-2011  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * This file is released under the GPLv2.  See the COPYING file for more
   5  * details.
   6  */
   7
   8 #ifndef __PAGE_H
   9 #define __PAGE_H
  10
  11 #include <list.h>
  12
  13 #define PAGE_SHIFT      12
  14 #define PAGE_SIZE       (1<<PAGE_SHIFT)
  15 #define PAGE_MASK       (PAGE_SIZE-1)
  16
  17 #define PAGE_INFO_BASE  ((struct page*) 0x400000)
  18
  19 #define ZONE_NORMAL     0
  20 #define ZONE_LOW        1
  21
  22 #define ZONE_NORMAL_MAX_ORDER   (64-PAGE_SHIFT)
  23 #define ZONE_LOW_MAX_ORDER      (31-PAGE_SHIFT)
  24
  25 /*
  26  * This structure describes a page of memory
  27  */
  28 struct page {
  29         union {
  30                 struct list_head buddy; /* buddy allocator list */
  31                 struct list_head guest; /* guest storage list */
  32         };
  33 };
  34
  35 /*
  36  * Externs
  37  */
  38 extern void init_pages(void);
  39
  40 /*
  41  * Static inlines
  42  */
  43 static inline struct page *page_num_to_ptr(u64 pnum)
  44 {
  45         struct page *base = PAGE_INFO_BASE;
  46
  47         return &base[pnum];
  48 }
  49
  50 static inline void *page_to_addr(struct page *page)
  51 {
  52         u64 pagenum = (((u64) page) - ((u64) PAGE_INFO_BASE)) / sizeof(struct page);
  53
  54         return (void*) (pagenum << PAGE_SHIFT);
  55 }
  56
  57 static inline struct page *addr_to_page(void *addr)
  58 {
  59         struct page *base = PAGE_INFO_BASE;
  60
  61         return &base[((u64) addr) >> PAGE_SHIFT];
  62 }
  63
  64 static inline int IS_LOW_ZONE(struct page *page)
  65 {
  66         return ((u64) page_to_addr(page)) < (2UL*1024*1024*1024);
  67 }
  68
  69 static inline int ZONE_TYPE(struct page *page)
  70 {
  71         return IS_LOW_ZONE(page) ? ZONE_LOW : ZONE_NORMAL;
  72 }
  73
  74 /*
  75  * This should be as simple as a cast, but unfortunately, the BUG_ON check
  76  * is there to make sure we never submit a truncated address to the channels
  77  *
  78  * In the future, the io code should check if IDA is necessary, and in that
  79  * case allocate an IDAL & set the IDA ccw flag. Other parts of the system
  80  * that require 31-bit address should do whatever their equivalent action
  81  * is.
  82  */
  83 static inline u32 ADDR31(void *ptr)
  84 {
  85         u64 ip = (u64) ptr;
  86
  87         BUG_ON(ip & ~0x7fffffffull);
  88
  89         return (u32) ip;
  90 }
  91
  92 static inline u64 ADDR64(void *ptr)
  93 {
  94         return (u64) ptr;
  95 }
  96
  97 #endif