From 6ebd4d038dbb626a43d87db3007e71f92f49d7b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 31 Jan 2013 11:08:03 +0100
Subject: [PATCH] ARM: stub out read_cpuid and read_cpuid_ext for CPU_CP15=n
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Traditionally for !CPU_CP15 read_cpuid and read_cpuid_ext returned the
processor id independent of the parameter passed in. This is wrong of
course but theoretically this doesn't harm because it's only called on
machines having a cp15.
Instead return 0 unconditionally which might make unused code paths be
better optimizable and so smaller and warn about unexpected usage.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-2-git-send-email-u.kleine-koenig@pengutronix.de
---
arch/arm/include/asm/cputype.h | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index a59dcb5ab5fce..574269ed2232d 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -50,6 +50,7 @@ extern unsigned int processor_id;
: "cc"); \
__val; \
})
+
#define read_cpuid_ext(ext_reg) \
({ \
unsigned int __val; \
@@ -59,11 +60,24 @@ extern unsigned int processor_id;
: "cc"); \
__val; \
})
-#else
-#define read_cpuid(reg) (processor_id)
-#define read_cpuid_ext(reg) 0
-#endif
+
+#else /* ifdef CONFIG_CPU_CP15 */
+/*
+ * read_cpuid and read_cpuid_ext should only ever be called on machines that
+ * have cp15 so warn on other usages.
+ */
+#define read_cpuid(reg) \
+ ({ \
+ WARN_ON_ONCE(1); \
+ 0; \
+ })
+
+#define read_cpuid_ext(reg) read_cpuid(reg)
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
+#ifdef CONFIG_CPU_CP15
/*
* The CPU ID never changes at run time, so we might as well tell the
* compiler that it's constant. Use this function to read the CPU ID
@@ -74,6 +88,15 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
return read_cpuid(CPUID_ID);
}
+#else /* ifdef CONFIG_CPU_CP15 */
+
+static inline unsigned int __attribute_const__ read_cpuid_id(void)
+{
+ return processor_id;
+}
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
static inline unsigned int __attribute_const__ read_cpuid_cachetype(void)
{
return read_cpuid(CPUID_CACHETYPE);