CR ENGR00050116 Fix flawed implementation of XIP Macros

Patch for CR ENGR00050116 Fix flawed implementation of XIP Macros.
The existing flawed implementations of xip_currtime, xip_elasped_since
and xip_irqpending macros are fixed.  Applies to linux 2.6.22 kernel
for MX platforms.

http://www.bitshrine.org/gpp/linux-2.6.22-mx-CR-ENGR00050116-Fix-flawed-implementation-.patch

4 files changed, 29 insertions, 6 deletions

diff --git a/arch/arm/mach-mx27/time.c b/arch/arm/mach-mx27/time.c
index 30d8dbcb192c..3d471b053a5a 100644
--- a/arch/arm/mach-mx27/time.c
+++ b/arch/arm/mach-mx27/time.c
@@ -36,6 +36,7 @@
 #include <linux/io.h>
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
+#include <linux/mtd/xip.h>
 #include <asm/hardware.h>
 #include <asm/mach/time.h>
 
@@ -161,7 +162,7 @@ static struct irqaction timer_irq = {
 	.handler = mxc_timer_interrupt,
 };
 
-static cycle_t mxc_gpt_read(void)
+static cycle_t __xipram mxc_gpt_read(void)
 {
 	return __raw_readl(MXC_GPT_GPTCNT);
 }
diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index 4dd10c3f4c7e..5f83111c08db 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -35,6 +35,7 @@
 #include <linux/io.h>
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
+#include <linux/mtd/xip.h>
 #include <asm/hardware.h>
 #include <asm/mach/time.h>
 
@@ -185,7 +186,7 @@ static struct irqaction timer_irq = {
 	.handler = mxc_timer_interrupt,
 };
 
-static cycle_t mxc_gpt_read(void)
+static cycle_t __xipram mxc_gpt_read(void)
 {
 	return __raw_readl(MXC_GPT_GPTCNT);
 }
diff --git a/drivers/mtd/maps/mxc_nor.c b/drivers/mtd/maps/mxc_nor.c
index 14da2a28ea57..6c69e0164c73 100644
--- a/drivers/mtd/maps/mxc_nor.c
+++ b/drivers/mtd/maps/mxc_nor.c
@@ -22,6 +22,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
+#include <linux/clocksource.h>
 #include <asm/mach-types.h>
 #include <asm/mach/flash.h>
 
@@ -31,6 +32,8 @@
 static const char *part_probes[] = { "RedBoot", "cmdlinepart", NULL };
 #endif
 
+struct clocksource *mtd_xip_clksrc;
+
 struct mxcflash_info {
 	struct mtd_partition *parts;
 	struct mtd_info *mtd;
@@ -75,6 +78,8 @@ static int __devinit mxcflash_probe(struct platform_device *pdev)
 	info->map.size = size;
 	info->map.bankwidth = flash->width;
 
+	mtd_xip_clksrc = clocksource_get_next();
+
 	simple_map_init(&info->map);
 	info->mtd = do_map_probe(flash->map_name, &info->map);
 	if (!info->mtd) {
diff --git a/include/asm-arm/arch-mxc/mtd-xip.h b/include/asm-arm/arch-mxc/mtd-xip.h
index b934bc894662..e0e91d6b18ff 100644
--- a/include/asm-arm/arch-mxc/mtd-xip.h
+++ b/include/asm-arm/arch-mxc/mtd-xip.h
@@ -20,13 +20,29 @@
 #ifndef __ARCH_MXC_MTD_XIP_H__
 #define __ARCH_MXC_MTD_XIP_H__
 
+#include <linux/clocksource.h>
 #include <asm/hardware.h>
 #include <asm/arch/system.h>
+
 #define xip_irqpending()        \
-        (~(__raw_readl(AVIC_NIVECSR) & __raw_readl(AVIC_FIVECSR)))
-#define xip_currtime()          get_cycles()
-#define xip_elapsed_since(x)    \
-        (signed)(((xip_currtime() - (x)) * USEC_PER_SEC) / LATCH)
+        ((__raw_readl(AVIC_NIVECSR) & __raw_readl(AVIC_FIVECSR)) != 0xFFFFFFFF)
+
+extern struct clocksource *mtd_xip_clksrc;
+
+#define xip_currtime()  (unsigned long)clocksource_read(mtd_xip_clksrc)
+
+#if CLOCK_TICK_RATE > 1000000
+#define NUMERATOR	1
+#define DENOMINATOR	(CLOCK_TICK_RATE/1000000 + 1)
+#else
+#define NUMERATOR	(1000000/CLOCK_TICK_RATE)
+#define DENOMINATOR	1
+#endif
+
+static inline unsigned long xip_elapsed_since(unsigned long x)
+{
+	return (((xip_currtime() - x) * NUMERATOR) / DENOMINATOR);
+}
 
 /*
  * Wait For Interrupt command for XIP kernel to put CPU in Idle mode