1 /* SPDX-License-Identifier: GPL-2.0 */
2 /**
3  * \file drm_os_linux.h
4  * OS abstraction macros.
5  */
6 
7 #include <linux/interrupt.h>	/* For task queue support */
8 #include <linux/sched/signal.h>
9 #include <linux/delay.h>
10 #include <linux/io-64-nonatomic-lo-hi.h>
11 
12 /** Current process ID */
13 #define DRM_CURRENTPID			task_pid_nr(current)
14 #define DRM_UDELAY(d)			udelay(d)
15 /** Read a byte from a MMIO region */
16 #define DRM_READ8(map, offset)		readb(((void __iomem *)(map)->handle) + (offset))
17 /** Read a word from a MMIO region */
18 #define DRM_READ16(map, offset)         readw(((void __iomem *)(map)->handle) + (offset))
19 /** Read a dword from a MMIO region */
20 #define DRM_READ32(map, offset)		readl(((void __iomem *)(map)->handle) + (offset))
21 /** Write a byte into a MMIO region */
22 #define DRM_WRITE8(map, offset, val)	writeb(val, ((void __iomem *)(map)->handle) + (offset))
23 /** Write a word into a MMIO region */
24 #define DRM_WRITE16(map, offset, val)   writew(val, ((void __iomem *)(map)->handle) + (offset))
25 /** Write a dword into a MMIO region */
26 #define DRM_WRITE32(map, offset, val)	writel(val, ((void __iomem *)(map)->handle) + (offset))
27 
28 /** Read a qword from a MMIO region - be careful using these unless you really understand them */
29 #define DRM_READ64(map, offset)		readq(((void __iomem *)(map)->handle) + (offset))
30 /** Write a qword into a MMIO region */
31 #define DRM_WRITE64(map, offset, val)	writeq(val, ((void __iomem *)(map)->handle) + (offset))
32 
33 #define DRM_WAIT_ON( ret, queue, timeout, condition )		\
34 do {								\
35 	DECLARE_WAITQUEUE(entry, current);			\
36 	unsigned long end = jiffies + (timeout);		\
37 	add_wait_queue(&(queue), &entry);			\
38 								\
39 	for (;;) {						\
40 		__set_current_state(TASK_INTERRUPTIBLE);	\
41 		if (condition)					\
42 			break;					\
43 		if (time_after_eq(jiffies, end)) {		\
44 			ret = -EBUSY;				\
45 			break;					\
46 		}						\
47 		schedule_timeout((HZ/100 > 1) ? HZ/100 : 1);	\
48 		if (signal_pending(current)) {			\
49 			ret = -EINTR;				\
50 			break;					\
51 		}						\
52 	}							\
53 	__set_current_state(TASK_RUNNING);			\
54 	remove_wait_queue(&(queue), &entry);			\
55 } while (0)
56