root/include/drm/drm_os_linux.h

INCLUDED FROM

DEFINITIONS

1. readq
2. writeq

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

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

#ifndef readq
static inline u64 readq(void __iomem *reg)
{
        return ((u64) readl(reg)) | (((u64) readl(reg + 4UL)) << 32);
}

static inline void writeq(u64 val, void __iomem *reg)
{
        writel(val & 0xffffffff, reg);
        writel(val >> 32, reg + 0x4UL);
}
#endif

/** 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)