linux/compat.h: Add wait_event_timeout macro

Add  wait_event_timeout - sleep until a condition gets true or a
timeout elapses.

This is a stripped version of the same from Linux kernel with the
following u-boot specific modifications:
- no wait queues supported
- use u-boot timer to detect timeouts
- check for Ctrl-C pressed during wait

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com>
[trini: Drop atomic_read from gadget/ether.c as this has existed for a
        while and now causes problems]
Signed-off-by: Tom Rini <trini@konsulko.com>

diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c
index a939918..a8e8bfc 100644 (file)
--- a/drivers/usb/gadget/ether.c
+++ b/drivers/usb/gadget/ether.c
@@ -33,7 +33,6 @@
 
 #define USB_NET_NAME "usb_ether"
 
-#define atomic_read
 extern struct platform_data brd;
 
 

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 712eeae..363b2b9 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -1,12 +1,20 @@
 #ifndef _LINUX_COMPAT_H_
 #define _LINUX_COMPAT_H_
 
+#include <console.h>
 #include <log.h>
 #include <malloc.h>
+
+#include <asm/processor.h>
+
 #include <linux/types.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 
+#ifdef CONFIG_XEN
+#include <xen/events.h>
+#endif
+
 struct unused {};
 typedef struct unused unused_t;
 
@@ -122,6 +130,52 @@ static inline void kmem_cache_destroy(struct kmem_cache *cachep)
 #define add_wait_queue(...)    do { } while (0)
 #define remove_wait_queue(...) do { } while (0)
 
+#ifndef CONFIG_XEN
+#define eventchn_poll()
+#endif
+
+#define __wait_event_timeout(condition, timeout, ret)          \
+({                                                             \
+       ulong __ret = ret; /* explicit shadow */                \
+       ulong start = get_timer(0);                             \
+       for (;;) {                                              \
+               eventchn_poll();                                \
+               if (condition) {                                \
+                       __ret = 1;                              \
+                       break;                                  \
+       }                                                       \
+       if ((get_timer(start) > timeout) || ctrlc()) {          \
+               __ret = 0;                                      \
+               break;                                          \
+       }                                                       \
+       cpu_relax();                                            \
+       }                                                       \
+       __ret;                                                  \
+})
+
+/**
+ * wait_event_timeout() - Wait until the event occurs before the timeout.
+ * @wr_head: The wait queue to wait on.
+ * @condition: Expression for the event to wait for.
+ * @timeout: Maximum waiting time.
+ *
+ * We wait until the @condition evaluates to %true (succeed) or
+ * %false (@timeout elapsed).
+ *
+ * Return:
+ * 0 - if the @condition evaluated to %false after the @timeout elapsed
+ * 1 - if the @condition evaluated to %true
+ */
+#define wait_event_timeout(wq_head, condition, timeout)                        \
+({                                                                     \
+       ulong __ret;                                                    \
+       if (condition)                                                  \
+               __ret = 1;                                              \
+       else                                                            \
+               __ret = __wait_event_timeout(condition, timeout, __ret);\
+       __ret;                                                          \
+})
+
 #define KERNEL_VERSION(a,b,c)  (((a) << 16) + ((b) << 8) + (c))
 
 /* This is also defined in ARMv8's mmu.h */