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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2006-12-13 18:33:53 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-12-13 18:33:53 +0000
commit47fd705287e9377acd2a4cee9aeeea02867d2e54 (patch)
treea0772e2655771c6ec3e8511ae3f4d689e4d6ce54 /include
parent[ARM] 4016/1: prefetch macro is wrong wrt gcc's "delete-null-pointer-checks" (diff)
downloadlinux-dev-47fd705287e9377acd2a4cee9aeeea02867d2e54.tar.xz
linux-dev-47fd705287e9377acd2a4cee9aeeea02867d2e54.zip
[ARM] Provide a method to alter the control register
i.MX needs to tweak the control register to support CPU frequency scaling. Rather than have folk blindly try and change the control register by writing to it and then wondering why it doesn't work, provide a method (which is safe for UP only, and therefore only available for UP) to achieve this. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'include')
-rw-r--r--include/asm-arm/system.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h
index f60faccf01fa..e160aeb0138d 100644
--- a/include/asm-arm/system.h
+++ b/include/asm-arm/system.h
@@ -173,6 +173,26 @@ static inline void set_copro_access(unsigned int val)
extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
extern unsigned long cr_alignment; /* defined in entry-armv.S */
+#ifndef CONFIG_SMP
+static inline void adjust_cr(unsigned long mask, unsigned long set)
+{
+ unsigned long flags, cr;
+
+ mask &= ~CR_A;
+
+ set &= mask;
+
+ local_irq_save(flags);
+
+ cr_no_alignment = (cr_no_alignment & ~mask) | set;
+ cr_alignment = (cr_alignment & ~mask) | set;
+
+ set_cr((get_cr() & ~mask) | set);
+
+ local_irq_restore(flags);
+}
+#endif
+
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)
#define UDBG_BADABORT (1 << 2)