/* SPDX-License-Identifier: GPL-2.0 */
  /**
   * \file drm_os_linux.h
   * OS abstraction macros.
   */
  
  #include <linux/interrupt.h>	/* For task queue support */
  #include <linux/sched/signal.h>
  #include <linux/delay.h>
  #include <linux/io-64-nonatomic-lo-hi.h>
  
  /** Current process ID */
  #define DRM_CURRENTPID			task_pid_nr(current)
  #define DRM_UDELAY(d)			udelay(d)
  /** Read a byte from a MMIO region */
  #define DRM_READ8(map, offset)		readb(((void __iomem *)(map)->handle) + (offset))
  /** Read a word from a MMIO region */
  #define DRM_READ16(map, offset)         readw(((void __iomem *)(map)->handle) + (offset))
  /** Read a dword from a MMIO region */
  #define DRM_READ32(map, offset)		readl(((void __iomem *)(map)->handle) + (offset))
  /** Write a byte into a MMIO region */
  #define DRM_WRITE8(map, offset, val)	writeb(val, ((void __iomem *)(map)->handle) + (offset))
  /** Write a word into a MMIO region */
  #define DRM_WRITE16(map, offset, val)   writew(val, ((void __iomem *)(map)->handle) + (offset))
  /** Write a dword into a MMIO region */
  #define DRM_WRITE32(map, offset, val)	writel(val, ((void __iomem *)(map)->handle) + (offset))
  
  /** Read a qword from a MMIO region - be careful using these unless you really understand them */
  #define DRM_READ64(map, offset)		readq(((void __iomem *)(map)->handle) + (offset))
  /** Write a qword into a MMIO region */
  #define DRM_WRITE64(map, offset, val)	writeq(val, ((void __iomem *)(map)->handle) + (offset))
  
  #define DRM_WAIT_ON( ret, queue, timeout, condition )		\
  do {								\
  	DECLARE_WAITQUEUE(entry, current);			\
  	unsigned long end = jiffies + (timeout);		\
  	add_wait_queue(&(queue), &entry);			\
  								\
  	for (;;) {						\
  		__set_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;					\
  		}						\
  	}							\
  	__set_current_state(TASK_RUNNING);			\
  	remove_wait_queue(&(queue), &entry);			\
  } while (0)