[PATCH v4] ARM: cache-l2x0.c: save aux ctrl for resume in case l2x0 is enabled before init

[Yilu Mao]

If l2x0 controller has been enabled when calling l2x0_init, the aux ctrl
register will not be saved in l2x0_saved_regs. Therefore we can not use
l2x0_saved_regs.aux_ctrl for resume later. This patch fixed the problem
by saving aux ctrl in l2x0_saved_regs just after it's being read from
the register.
And in case some bits of aux ctrl register are reserved, re-read and
save it properly after set it if l2x0 is disabled before init.

Change-Id: I54f3002274ffe9cdc667dba81e36e08f2e121467
Signed-off-by: Yilu Mao <ylmao at marvell.com>
---
 arch/arm/mm/cache-l2x0.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index a53fd2a..9893e58 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -320,6 +320,13 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
 	cache_id = readl_relaxed(l2x0_base + L2X0_CACHE_ID);
 	aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
 
+	/*
+	 * In case l2x controller is enabled, the aux ctrl register
+	 * can't be set. So the original value should be stored in
+	 * the l2x0_saved_regs for restoring when resume.
+	 */
+	l2x0_saved_regs.aux_ctrl = aux;
+
 	aux &= aux_mask;
 	aux |= aux_val;
 
@@ -364,6 +371,8 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
 		/* l2x0 controller is disabled */
 		writel_relaxed(aux, l2x0_base + L2X0_AUX_CTRL);
 
+		/* Re-read it in case some bits are reserved. */
+		aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
 		l2x0_saved_regs.aux_ctrl = aux;
 
 		l2x0_inv_all();
-- 
1.7.5.4