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Commit 47fd7052 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 02828845

include/asm-arm/system.h

+20 −0
Original line number Diff line number Diff line
@@ -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)