drm: add DRM_READ/WRITE64 wrappers around readq/writeq.
The readq/writeq stuff is from Dave Miller, and he
warns users to be careful about using these. Plans are only
r600 to use it so far.
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_os_linux.h b/include/drm/drm_os_linux.h
index 8dbd257..013551d 100644
--- a/include/drm/drm_os_linux.h
+++ b/include/drm/drm_os_linux.h
@@ -6,6 +6,19 @@
#include <linux/interrupt.h> /* For task queue support */
#include <linux/delay.h>
+#ifndef readq
+static u64 readq(void __iomem *reg)
+{
+ return ((u64) readl(reg)) | (((u64) readl(reg + 4UL)) << 32);
+}
+
+static 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_SUSER(p) capable(CAP_SYS_ADMIN)
@@ -23,6 +36,12 @@
/** Write a dword into a MMIO region */
#define DRM_WRITE32(map, offset, val) writel(val, ((void __iomem *)(map)->handle) + (offset))
/** Read memory barrier */
+
+/** 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_READMEMORYBARRIER() rmb()
/** Write memory barrier */
#define DRM_WRITEMEMORYBARRIER() wmb()