Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / mtd / xip.h

diff --git a/kernel/include/linux/mtd/xip.h b/kernel/include/linux/mtd/xip.h
new file mode 100644 (file)
index 0000000..abed4de
--- /dev/null
+++ b/kernel/include/linux/mtd/xip.h
@@ -0,0 +1,99 @@
+/*
+ * MTD primitives for XIP support
+ *
+ * Author:     Nicolas Pitre
+ * Created:    Nov 2, 2004
+ * Copyright:  (C) 2004 MontaVista Software, Inc.
+ *
+ * This XIP support for MTD has been loosely inspired
+ * by an earlier patch authored by David Woodhouse.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __LINUX_MTD_XIP_H__
+#define __LINUX_MTD_XIP_H__
+
+
+#ifdef CONFIG_MTD_XIP
+
+/*
+ * We really don't want gcc to guess anything.
+ * We absolutely _need_ proper inlining.
+ */
+#include <linux/compiler.h>
+
+/*
+ * Function that are modifying the flash state away from array mode must
+ * obviously not be running from flash.  The __xipram is therefore marking
+ * those functions so they get relocated to ram.
+ */
+#define __xipram noinline __attribute__ ((__section__ (".data")))
+
+/*
+ * Each architecture has to provide the following macros.  They must access
+ * the hardware directly and not rely on any other (XIP) functions since they
+ * won't be available when used (flash not in array mode).
+ *
+ * xip_irqpending()
+ *
+ *     return non zero when any hardware interrupt is pending.
+ *
+ * xip_currtime()
+ *
+ *     return a platform specific time reference to be used with
+ *     xip_elapsed_since().
+ *
+ * xip_elapsed_since(x)
+ *
+ *     return in usecs the elapsed timebetween now and the reference x as
+ *     returned by xip_currtime().
+ *
+ *     note 1: conversion to usec can be approximated, as long as the
+ *             returned value is <= the real elapsed time.
+ *     note 2: this should be able to cope with a few seconds without
+ *             overflowing.
+ *
+ * xip_iprefetch()
+ *
+ *      Macro to fill instruction prefetch
+ *     e.g. a series of nops:  asm volatile (".rep 8; nop; .endr");
+ */
+
+#include <asm/mtd-xip.h>
+
+#ifndef xip_irqpending
+
+#warning "missing IRQ and timer primitives for XIP MTD support"
+#warning "some of the XIP MTD support code will be disabled"
+#warning "your system will therefore be unresponsive when writing or erasing flash"
+
+#define xip_irqpending()       (0)
+#define xip_currtime()         (0)
+#define xip_elapsed_since(x)   (0)
+
+#endif
+
+#ifndef xip_iprefetch
+#define xip_iprefetch()                do { } while (0)
+#endif
+
+/*
+ * xip_cpu_idle() is used when waiting for a delay equal or larger than
+ * the system timer tick period.  This should put the CPU into idle mode
+ * to save power and to be woken up only when some interrupts are pending.
+ * This should not rely upon standard kernel code.
+ */
+#ifndef xip_cpu_idle
+#define xip_cpu_idle()  do { } while (0)
+#endif
+
+#else
+
+#define __xipram
+
+#endif /* CONFIG_MTD_XIP */
+
+#endif /* __LINUX_MTD_XIP_H__ */