/**
 * \file drm_os_linux.h
 * OS abstraction macros.
 */


#include <linux/interrupt.h>	/* For task queue support */
#include <linux/delay.h>

/** File pointer type */
#define DRMFILE                         struct file *
/** Ioctl arguments */
#define DRM_IOCTL_ARGS			struct inode *inode, struct file *filp, unsigned int cmd, unsigned long data
#define DRM_ERR(d)			-(d)
/** Current process ID */
#define DRM_CURRENTPID			current->pid
#define DRM_UDELAY(d)			udelay(d)
/** Read a byte from a MMIO region */
#define DRM_READ8(map, offset)		readb(((unsigned long)(map)->handle) + (offset))
/** Read a dword from a MMIO region */
#define DRM_READ32(map, offset)		readl(((unsigned long)(map)->handle) + (offset))
/** Write a byte into a MMIO region */
#define DRM_WRITE8(map, offset, val)	writeb(val, ((unsigned long)(map)->handle) + (offset))
/** Write a dword into a MMIO region */
#define DRM_WRITE32(map, offset, val)	writel(val, ((unsigned long)(map)->handle) + (offset))
/** Read memory barrier */
#define DRM_READMEMORYBARRIER()		rmb()
/** Write memory barrier */
#define DRM_WRITEMEMORYBARRIER()	wmb()
/** Read/write memory barrier */
#define DRM_MEMORYBARRIER()		mb()
/** DRM device local declaration */
#define DRM_DEVICE	drm_file_t	*priv	= filp->private_data; \
			drm_device_t	*dev	= priv->dev

/** IRQ handler arguments and return type and values */
#define DRM_IRQ_ARGS		int irq, void *arg, struct pt_regs *regs

/** AGP types */
#define DRM_AGP_MEM		struct agp_memory
#define DRM_AGP_KERN		struct agp_kern_info

/** Task queue handler arguments */
#define DRM_TASKQUEUE_ARGS	void *arg

/** For data going into the kernel through the ioctl argument */
#define DRM_COPY_FROM_USER_IOCTL(arg1, arg2, arg3)	\
	if ( copy_from_user(&arg1, arg2, arg3) )	\
		return -EFAULT
/** For data going from the kernel through the ioctl argument */
#define DRM_COPY_TO_USER_IOCTL(arg1, arg2, arg3)	\
	if ( copy_to_user(arg1, &arg2, arg3) )		\
		return -EFAULT
/** Other copying of data to kernel space */
#define DRM_COPY_FROM_USER(arg1, arg2, arg3)		\
	copy_from_user(arg1, arg2, arg3)
/** Other copying of data from kernel space */
#define DRM_COPY_TO_USER(arg1, arg2, arg3)		\
	copy_to_user(arg1, arg2, arg3)
/* Macros for copyfrom user, but checking readability only once */
#define DRM_VERIFYAREA_READ( uaddr, size ) 		\
	verify_area( VERIFY_READ, uaddr, size )
#define DRM_COPY_FROM_USER_UNCHECKED(arg1, arg2, arg3) 	\
	__copy_from_user(arg1, arg2, arg3)
#define DRM_GET_USER_UNCHECKED(val, uaddr)		\
	__get_user(val, uaddr)


/** 'malloc' without the overhead of DRM(alloc)() */
#define DRM_MALLOC(x) kmalloc(x, GFP_KERNEL)
/** 'free' without the overhead of DRM(free)() */
#define DRM_FREE(x,size) kfree(x)

/** 
 * Get the pointer to the SAREA.
 *
 * Searches the SAREA on the mapping lists and points drm_device::sarea to it.
 */
#define DRM_GETSAREA()							 \
do { 									 \
	drm_map_list_t *entry;						 \
	list_for_each_entry( entry, &dev->maplist->head, head ) {	 \
		if ( entry->map &&					 \
		     entry->map->type == _DRM_SHM &&			 \
		     (entry->map->flags & _DRM_CONTAINS_LOCK) ) {	 \
			dev_priv->sarea = entry->map;			 \
 			break;						 \
 		}							 \
 	}								 \
} while (0)

#define DRM_HZ HZ

#define DRM_WAIT_ON( ret, queue, timeout, condition )		\
do {								\
	DECLARE_WAITQUEUE(entry, current);			\
	unsigned long end = jiffies + (timeout);		\
	add_wait_queue(&(queue), &entry);			\
								\
	for (;;) {						\
		current->state = TASK_INTERRUPTIBLE;		\
		if (condition)					\
			break;					\
		if (time_after_eq(jiffies, end)) {		\
			ret = -EBUSY;				\
			break;					\
		}						\
		schedule_timeout((HZ/100 > 1) ? HZ/100 : 1);	\
		if (signal_pending(current)) {			\
			ret = -EINTR;				\
			break;					\
		}						\
	}							\
	current->state = TASK_RUNNING;				\
	remove_wait_queue(&(queue), &entry);			\
} while (0)


#define DRM_WAKEUP( queue ) wake_up_interruptible( queue )
#define DRM_INIT_WAITQUEUE( queue ) init_waitqueue_head( queue )