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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/include/linux/mtd/xip.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/include/linux/mtd/xip.h')
-rw-r--r--kernel/include/linux/mtd/xip.h99
1 files changed, 99 insertions, 0 deletions
diff --git a/kernel/include/linux/mtd/xip.h b/kernel/include/linux/mtd/xip.h
new file mode 100644
index 000000000..abed4dec5
--- /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__ */