📄 sysdep.h
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/*
* sysdep.h -- centralizing compatibility issues between 2.0, 2.2, 2.4
*
* Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
* Copyright (C) 2001 O'Reilly & Associates
*
* The source code in this file can be freely used, adapted,
* and redistributed in source or binary form, so long as an
* acknowledgment appears in derived source files. The citation
* should list that the code comes from the book "Linux Device
* Drivers" by Alessandro Rubini and Jonathan Corbet, published
* by O'Reilly & Associates. No warranty is attached;
* we cannot take responsibility for errors or fitness for use.
*
*/
#ifndef _SYSDEP_H_
# define _SYSDEP_H_
# ifndef LINUX_VERSION_CODE
# include <linux/version.h>
# endif
# ifndef KERNEL_VERSION /* pre-2.1.90 didn't have it */
# define KERNEL_VERSION(vers,rel,seq) ( ((vers)<<16) | ((rel)<<8) | (seq) )
# endif
/* only allow 2.0.x 2.2.y and 2.4.z */
# if LINUX_VERSION_CODE < KERNEL_VERSION(2,0,0) /* not < 2.0 */
# error "This kernel is too old: not supported by this file"
# endif
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0) /* not > 2.4, by now */
# error "This kernel is too recent: not supported by this file"
# endif
# if (LINUX_VERSION_CODE & 0xff00) == 1 /* not 2.1 */
# error "Please don't use linux-2.1, use 2.2 or 2.4 instead"
# endif
# if (LINUX_VERSION_CODE & 0xff00) == 3 /* not 2.3 */
# error "Please don't use linux-2.3, use 2.4 instead"
# endif
/* remember about the current version */
# if LINUX_VERSION_CODE < KERNEL_VERSION(2,1,0)
# define LINUX_20
# elif LINUX_VERSION_CODE < KERNEL_VERSION(2,3,0)
# define LINUX_22
# else
# define LINUX_24
# endif
/* we can't support versioning in pre-2.4 because we #define some functions */
# if !defined(LINUX_24) && defined(CONFIG_MODVERSIONS)
# error "This sysdep.h can't support CONFIG_MODVERSIONS"
# error "and old kernels at the same time."
# error "Either use 2.4 or avoid using versioning"
# endif
# ifndef LINUX_20 /* include vmalloc.h if this is 2.2/2.4 */
# ifdef VM_READ /* a typical flag defined by mm.h */
# include <linux/vmalloc.h>
# endif
# endif
# include <linux/slab.h>
# include <linux/sched.h>
/* Modularization issues */
# ifdef LINUX_20
# define __USE_OLD_SYMTAB__
# define EXPORT_NO_SYMBOLS register_symtab(NULL);
# define REGISTER_SYMTAB(tab) register_symtab(tab)
# else
# define REGISTER_SYMTAB(tab) /* nothing */
# endif
# ifdef __USE_OLD_SYMTAB__
# define __MODULE_STRING(s) /* nothing */
# define MODULE_PARM(v,t) /* nothing */
# define MODULE_PARM_DESC(v,t) /* nothing */
# define MODULE_AUTHOR(n) /* nothing */
# define MODULE_DESCRIPTION(d) /* nothing */
# define MODULE_SUPPORTED_DEVICE(n) /* nothing */
# endif
/*
* In version 2.2 (up to 2.2.19, at least), the macro for request_module()
* when no kmod is there is wrong. It's a "do {} while 0" but it shouldbe int
*/
# ifdef LINUX_22
# ifndef CONFIG_KMOD
# undef request_module
# define request_module(name) -ENOSYS
# endif
# endif
# ifndef LINUX_20
# include <linux/init.h> /* module_init/module_exit */
# endif
# ifndef module_init
# define module_init(x) int init_module(void) { return x(); }
# define module_exit(x) void cleanup_module(void) { x(); }
# endif
# ifndef SET_MODULE_OWNER
# define SET_MODULE_OWNER(structure) /* nothing */
# endif
/*
* "select" changed in 2.1.23. The implementation is twin, but this
* header is new
*
*/
# ifdef LINUX_20
# define __USE_OLD_SELECT__
# else
# include <linux/poll.h>
# endif
# ifdef LINUX_20
# define INODE_FROM_F(filp) ((filp)->f_inode)
# else
# define INODE_FROM_F(filp) ((filp)->f_dentry->d_inode)
# endif
/* Other changes in the fops are solved using wrappers */
/*
* Wait queues changed with 2.3
*/
# ifndef DECLARE_WAIT_QUEUE_HEAD
# define DECLARE_WAIT_QUEUE_HEAD(head) struct wait_queue *head = NULL
typedef struct wait_queue *wait_queue_head_t;
# define init_waitqueue_head(head) (*(head)) = NULL
/* offer wake_up_sync as an alias for wake_up */
# define wake_up_sync(head) wake_up(head)
# define wake_up_interruptible_sync(head) wake_up_interruptible(head)
/* Pretend we have add_wait_queue_exclusive */
# define add_wait_queue_exclusive(q,entry) add_wait_queue ((q), (entry))
# endif /* no DECLARE_WAIT_QUEUE_HEAD */
/*
* Define wait_event for 2.0 kernels. (This ripped off directly from
* the 2.2.18 sched.h)
*/
# ifdef LINUX_20
# define __wait_event(wq, condition) \
do { \
struct wait_queue __wait; \
\
__wait.task = current; \
add_wait_queue(&wq, &__wait); \
for (;;) { \
current->state = TASK_UNINTERRUPTIBLE; \
mb(); \
if (condition) \
break; \
schedule(); \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&wq, &__wait); \
} while (0)
# define wait_event(wq, condition) \
do { \
if (condition) \
break; \
__wait_event(wq, condition); \
} while (0)
# define __wait_event_interruptible(wq, condition, ret) \
do { \
struct wait_queue __wait; \
\
__wait.task = current; \
add_wait_queue(&wq, &__wait); \
for (;;) { \
current->state = TASK_INTERRUPTIBLE; \
mb(); \
if (condition) \
break; \
if (!signal_pending(current)) { \
schedule(); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
current->state = TASK_RUNNING; \
remove_wait_queue(&wq, &__wait); \
} while (0)
# define wait_event_interruptible(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
__wait_event_interruptible(wq, condition, __ret); \
__ret; \
})
# endif
/*
* 2.3 added tasklets
*/
# ifdef LINUX_24
# define HAVE_TASKLETS
# endif
/* FIXME: implement the other versions of wake_up etc */
/*
* access to user space: use the 2.2 functions,
* and implement them as macros for 2.0
*/
# ifdef LINUX_20
# include <asm/segment.h>
# define access_ok(t,a,sz) (verify_area((t),(void *) (a),(sz)) ? 0 : 1)
# define verify_area_20 verify_area
# define copy_to_user(t,f,n) (memcpy_tofs((t), (f), (n)), 0)
# define copy_from_user(t,f,n) (memcpy_fromfs((t), (f), (n)), 0)
# define __copy_to_user(t,f,n) copy_to_user((t), (f), (n))
# define __copy_from_user(t,f,n) copy_from_user((t), (f), (n))
# define PUT_USER(val,add) (put_user((val),(add)), 0)
# define __PUT_USER(val,add) PUT_USER((val),(add))
# define GET_USER(dest,add) ((dest)=get_user((add)), 0)
# define __GET_USER(dest,add) GET_USER((dest),(add))
# else
# include <asm/uaccess.h>
# include <asm/io.h>
# define verify_area_20(t,a,sz) (0) /* == success */
# define PUT_USER put_user
# define __PUT_USER __put_user
# define GET_USER get_user
# define __GET_USER __get_user
# endif
/*
* Allocation issues
*/
# ifdef GFP_USER /* only if mm.h has been included */
# ifdef LINUX_20
# define __GFP_DMA GFP_DMA /* 2.0 didn't have the leading __ */
# endif
# ifndef LINUX_24
# define __GFP_HIGHMEM 0 /* was not there */
# define GFP_HIGHUSER 0 /* idem */
# endif
# ifdef LINUX_20
# define __get_free_pages(a,b) __get_free_pages((a),(b),0)
# endif
# ifndef LINUX_24
# define get_zeroed_page get_free_page
# endif
# endif
/* ioremap */
# if defined(LINUX_20) && defined(_LINUX_MM_H)
# define ioremap_nocache ioremap
# ifndef __i386__
/* This simple approach works for non-PC platforms. */
# define ioremap vremap
# define iounmap vfree
# else /* the PC has <expletive> ISA; 2.2 and 2.4 remap it, 2.0 needs not */
extern inline void *ioremap(unsigned long phys_addr, unsigned long size)
{
if (phys_addr >= 0xA0000 && phys_addr + size <= 0x100000)
return (void *)phys_addr;
return vremap(phys_addr, size);
}
extern inline void iounmap(void *addr)
{
if ((unsigned long)addr >= 0xA0000
&& (unsigned long)addr < 0x100000)
return;
vfree(addr);
}
# endif
# endif
/* Also, define check_mem_region etc */
# ifndef LINUX_24
# define check_mem_region(a,b) 0 /* success */
# define request_mem_region(a,b,c) /* nothing */
# define release_mem_region(a,b) /* nothing */
# endif
/* implement capable() for 2.0 */
# ifdef LINUX_20
# define capable(anything) suser()
# endif
/* The use_count of exec_domain and binfmt changed in 2.1.23 */
# ifdef LINUX_20
# define INCRCOUNT(p) ((p)->module ? __MOD_INC_USE_COUNT((p)->module) : 0)
# define DECRCOUNT(p) ((p)->module ? __MOD_DEC_USE_COUNT((p)->module) : 0)
# define CURRCOUNT(p) ((p)->module && (p)->module->usecount)
# else
# define INCRCOUNT(p) ((p)->use_count++)
# define DECRCOUNT(p) ((p)->use_count--)
# define CURRCOUNT(p) ((p)->use_count)
# endif
/*
* /proc has changed a lot across the versions...
*/
# ifdef LINUX_20
# define USE_PROC_REGISTER
# endif
/*
* 2.2 didn't have create_proc_{read|info}_entry yet.
* And it looks like there are no other "interesting" entry point, as
* the rest is somehow esotique (mknod, symlink, ...)
*/
# ifdef LINUX_22
# ifdef PROC_SUPER_MAGIC /* Only if procfs is being used */
extern inline struct proc_dir_entry *create_proc_read_entry(const char *name,
mode_t mode, struct proc_dir_entry *base,
read_proc_t *read_proc, void * data)
{
struct proc_dir_entry *res=create_proc_entry(name,mode,base);
if (res)
{
res->read_proc=read_proc;
res->data=data;
}
return res;
}
# ifndef create_proc_info_entry /* added in 2.2.18 */
typedef int (get_info_t)(char *, char **, off_t, int, int);
extern inline struct proc_dir_entry *create_proc_info_entry(const char *name,
mode_t mode, struct proc_dir_entry *base, get_info_t *get_info)
{
struct proc_dir_entry *res=create_proc_entry(name,mode,base);
if (res) res->get_info=get_info;
return res;
}
# endif /* no create_proc_info_entry */
# endif
# endif
# ifdef LINUX_20
# define test_and_set_bit(nr,addr) test_bit((nr),(addr))
# define test_and_clear_bit(nr,addr) clear_bit((nr),(addr))
# define test_and_change_bit(nr,addr) change_bit((nr),(addr))
# endif
/* 2.0 had no read and write memory barriers, and 2.2 lacks the
set_ functions */
# ifndef LINUX_24
# ifdef LINUX_20
# define wmb() mb() /* this is a big penalty on non-reordering platfs */
# define rmb() mb() /* this is a big penalty on non-reordering platfs */
# endif /* LINUX_20 */
# define set_mb() do { var = value; mb(); } while (0)
# define set_wmb() do { var = value; wmb(); } while (0)
# endif /* ! LINUX_24 */
/* 2.1.30 removed these functions. Let's define them, just in case */
# ifndef LINUX_20
# define queue_task_irq queue_task
# define queue_task_irq_off queue_task
# endif
/* 2.1.10 and 2.1.43 introduced new functions. They are worth using */
# ifdef LINUX_20
# include <asm/byteorder.h>
# ifdef __LITTLE_ENDIAN
# define cpu_to_le16(x) (x)
# define cpu_to_le32(x) (x)
# define cpu_to_be16(x) htons((x))
# define cpu_to_be32(x) htonl((x))
# else
# define cpu_to_be16(x) (x)
# define cpu_to_be32(x) (x)
extern inline __u16 cpu_to_le16(__u16 x) { return (x<<8) | (x>>8);}
extern inline __u32 cpu_to_le32(__u32 x)
{
return (x>>24) |
((x>>8)&0xff00) | ((x<<8)&0xff0000) | (x<<24);
}
# endif
# define le16_to_cpu(x) cpu_to_le16(x)
# define le32_to_cpu(x) cpu_to_le32(x)
# define be16_to_cpu(x) cpu_to_be16(x)
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