armv7: add functions for reading/writing L2CTLR

This adds simple accessor functions for reading/writing L2CTLR.

Change-Id: I2768d00d5bb2c43e84741ccead81e529dac9254d
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2948
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/arch/armv7/include/arch/cache.h b/src/arch/armv7/include/arch/cache.h
index f074a3b158..3e0ff2e1ce 100644
--- a/src/arch/armv7/include/arch/cache.h
+++ b/src/arch/armv7/include/arch/cache.h
@@ -219,6 +219,25 @@ static inline void write_csselr(uint32_t val)
 	isb();	/* ISB to sync the change to CCSIDR */
 }
 
+/* read L2 control register (L2CTLR) */
+static inline unsigned int read_l2ctlr(void)
+{
+	unsigned int val = 0;
+	asm volatile ("mrc p15, 1, %0, c9, c0, 2" : "=r" (val));
+	return val;
+}
+
+/* write L2 control register (L2CTLR) */
+static inline void write_l2ctlr(uint32_t val)
+{
+	/*
+	 * Note: L2CTLR can only be written when the L2 memory system
+	 * is idle, ie before the MMU is enabled.
+	 */
+	asm volatile("mcr p15, 1, %0, c9, c0, 2" : : "r" (val) : "memory" );
+	isb();
+}
+
 /* read system control register (SCTLR) */
 static inline unsigned int read_sctlr(void)
 {