include/linux/compatmac.h

   1   /*
   2    * This header tries to allow you to write 2.3-compatible drivers,
   3    * but (using this header) still allows you to run them on 2.2 and
   4    * 2.0 kernels.
   5    *
   6    * Sometimes, a #define replaces a "construct" that older kernels
   7    * had. For example,
   8    *
   9    *       DECLARE_MUTEX(name);
  10    *
  11    * replaces the older
  12    *
  13    *       struct semaphore name = MUTEX;
  14    *
  15    * This file then declares the DECLARE_MUTEX macro to compile into the
  16    * older version.
  17    *
  18    * In some cases, a macro or function changes the number of arguments.
  19    * In that case, there is nothing we can do except define an access
  20    * macro that provides the same functionality on both versions of Linux.
  21    *
  22    * This is the case for example with the "get_user" macro 2.0 kernels use:
  23    *
  24    *          a = get_user (b);
  25    *
  26    * while newer kernels use
  27    *
  28    *          get_user (a,b);
  29    *
  30    * This is unfortunate. We therefore define "Get_user (a,b)" which looks
  31    * almost the same as the 2.2+ construct, and translates into the
  32    * appropriate sequence for earlier constructs.
  33    *
  34    * Supported by this file are the 2.0 kernels, 2.2 kernels, and the
  35    * most recent 2.3 kernel. 2.3 support will be dropped as soon when 2.4
  36    * comes out. 2.0 support may someday be dropped. But then again, maybe
  37    * not.
  38    *
  39    * I'll try to maintain this, provided that Linus agrees with the setup.
  40    * Feel free to mail updates or suggestions.
  41    *
  42    * -- R.E.Wolff@BitWizard.nl
  43    *
  44    */
  45
  46 #ifndef COMPATMAC_H
  47 #define COMPATMAC_H
  48
  49 #include <linux/version.h>
  50
  51 #if LINUX_VERSION_CODE < 0x020100    /* Less than 2.1.0 */
  52 #define TWO_ZERO
  53 #else
  54 #if LINUX_VERSION_CODE < 0x020200   /* less than 2.2.x */
  55 #warning "Please use a 2.2.x kernel. "
  56 #else
  57 #if LINUX_VERSION_CODE < 0x020300   /* less than 2.3.x */
  58 #define TWO_TWO
  59 #else
  60 #define TWO_THREE
  61 #endif
  62 #endif
  63 #endif
  64
  65 #ifdef TWO_ZERO
  66
  67 /* Here is the section that makes the 2.2 compatible driver source
  68    work for 2.0 too! We mostly try to adopt the "new thingies" from 2.2,
  69    and provide for compatibility stuff here if possible. */
  70
  71 /* Some 200 days (on intel) */
  72 #define MAX_SCHEDULE_TIMEOUT     ((long)(~0UL>>1))
  73
  74 #include <linux/bios32.h>
  75
  76 #define Get_user(a,b)                a = get_user(b)
  77 #define Put_user(a,b)                0,put_user(a,b)
  78 #define copy_to_user(a,b,c)          memcpy_tofs(a,b,c)
  79
  80 static inline int copy_from_user(void *to,const void *from, int c)
  81 {
  82   memcpy_fromfs(to, from, c);
  83   return 0;
  84 }
  85
  86 #define pci_present                  pcibios_present
  87 #define pci_read_config_word         pcibios_read_config_word
  88 #define pci_read_config_dword        pcibios_read_config_dword
  89
  90 static inline unsigned char get_irq (unsigned char bus, unsigned char fn)
  91 {
  92         unsigned char t;
  93         pcibios_read_config_byte (bus, fn, PCI_INTERRUPT_LINE, &t);
  94         return t;
  95 }
  96
  97 static inline void *ioremap(unsigned long base, long length)
  98 {
  99         if (base < 0x100000) return (void *)base;
 100         return vremap (base, length);
 101 }
 102
 103 #define my_iounmap(x, b)             (((long)x<0x100000)?0:vfree ((void*)x))
 104
 105 #define capable(x)                   suser()
 106
 107 #define queue_task                   queue_task_irq_off
 108 #define tty_flip_buffer_push(tty)    queue_task(&tty->flip.tqueue, &tq_timer)
 109 #define signal_pending(current)      (current->signal & ~current->blocked)
 110 #define schedule_timeout(to)         do {current->timeout = jiffies + (to);schedule ();} while (0)
 111 #define time_after(t1,t2)            (((long)t1-t2) > 0)
 112
 113
 114 #define test_and_set_bit(nr, addr)   set_bit(nr, addr)
 115 #define test_and_clear_bit(nr, addr) clear_bit(nr, addr)
 116
 117 /* Not yet implemented on 2.0 */
 118 #define ASYNC_SPD_SHI  -1
 119 #define ASYNC_SPD_WARP -1
 120
 121
 122 /* Ugly hack: the driver_name doesn't exist in 2.0.x . So we define it
 123    to the "name" field that does exist. As long as the assignments are
 124    done in the right order, there is nothing to worry about. */
 125 #define driver_name           name
 126
 127 /* Should be in a header somewhere. They are in tty.h on 2.2 */
 128 #define TTY_HW_COOK_OUT       14 /* Flag to tell ntty what we can handle */
 129 #define TTY_HW_COOK_IN        15 /* in hardware - output and input       */
 130
 131 /* The return type of a "close" routine. */
 132 #define INT                   void
 133 #define NO_ERROR              /* Nothing */
 134
 135 #else
 136
 137 /* The 2.2.x compatibility section. */
 138 #include <asm/uaccess.h>
 139
 140
 141 #define Get_user(a,b)         get_user(a,b)
 142 #define Put_user(a,b)         put_user(a,b)
 143 #define get_irq(pdev)         pdev->irq
 144
 145 #define INT                   int
 146 #define NO_ERROR              0
 147
 148 #define my_iounmap(x,b)       (iounmap((char *)(b)))
 149
 150 #endif
 151
 152 #ifndef TWO_THREE
 153 /* These are new in 2.3. The source now uses 2.3 syntax, and here is
 154    the compatibility define... */
 155 #define wait_queue_head_t     struct wait_queue *
 156 #define DECLARE_MUTEX(name)   struct semaphore name = MUTEX
 157 #define DECLARE_WAITQUEUE(wait, current) \
 158                               struct wait_queue wait = { current, NULL }
 159
 160 #endif
 161
 162
 163 #endif