openwrtv4/target/linux/bcm53xx/patches-4.1/073-ARM-l2c-only-unlock-caches-if-NS_LOCKDOWN-bit-is-set.patch

From e946a8cbe4a47a7c2615ffb0d45712e72c7d0f3a Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Fri, 15 May 2015 11:51:51 +0100
Subject: [PATCH 73/74] ARM: l2c: only unlock caches if NS_LOCKDOWN bit is set

Some L2C caches have a bit which allows non-secure software to control
the cache lockdown.  Some platforms are unable to set this bit.  To
avoid receiving an abort while trying to unlock the cache lines, check
the state of this bit before unlocking.  We do this by providing a new
method in the l2c_init_data to perform the unlocking.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mm/cache-l2x0.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -42,6 +42,7 @@ struct l2c_init_data {
 	void (*fixup)(void __iomem *, u32, struct outer_cache_fns *);
 	void (*save)(void __iomem *);
 	void (*configure)(void __iomem *);
+	void (*unlock)(void __iomem *, unsigned);
 	struct outer_cache_fns outer_cache;
 };
 
@@ -128,7 +129,7 @@ static void l2c_enable(void __iomem *bas
 	else
 		l2x0_data->configure(base);
 
-	l2c_unlock(base, num_lock);
+	l2x0_data->unlock(base, num_lock);
 
 	local_irq_save(flags);
 	__l2c_op_way(base + L2X0_INV_WAY);
@@ -249,6 +250,7 @@ static const struct l2c_init_data l2c210
 	.enable = l2c_enable,
 	.save = l2c_save,
 	.configure = l2c_configure,
+	.unlock = l2c_unlock,
 	.outer_cache = {
 		.inv_range = l2c210_inv_range,
 		.clean_range = l2c210_clean_range,
@@ -400,6 +402,12 @@ static void l2c220_enable(void __iomem *
 	l2c_enable(base, aux, num_lock);
 }
 
+static void l2c220_unlock(void __iomem *base, unsigned num_lock)
+{
+	if (readl_relaxed(base + L2X0_AUX_CTRL) & L220_AUX_CTRL_NS_LOCKDOWN)
+		l2c_unlock(base, num_lock);
+}
+
 static const struct l2c_init_data l2c220_data = {
 	.type = "L2C-220",
 	.way_size_0 = SZ_8K,
@@ -407,6 +415,7 @@ static const struct l2c_init_data l2c220
 	.enable = l2c220_enable,
 	.save = l2c_save,
 	.configure = l2c_configure,
+	.unlock = l2c220_unlock,
 	.outer_cache = {
 		.inv_range = l2c220_inv_range,
 		.clean_range = l2c220_clean_range,
@@ -755,6 +764,12 @@ static void l2c310_resume(void)
 		set_auxcr(get_auxcr() | BIT(3) | BIT(2) | BIT(1));
 }
 
+static void l2c310_unlock(void __iomem *base, unsigned num_lock)
+{
+	if (readl_relaxed(base + L2X0_AUX_CTRL) & L310_AUX_CTRL_NS_LOCKDOWN)
+		l2c_unlock(base, num_lock);
+}
+
 static const struct l2c_init_data l2c310_init_fns __initconst = {
 	.type = "L2C-310",
 	.way_size_0 = SZ_8K,
@@ -763,6 +778,7 @@ static const struct l2c_init_data l2c310
 	.fixup = l2c310_fixup,
 	.save = l2c310_save,
 	.configure = l2c310_configure,
+	.unlock = l2c310_unlock,
 	.outer_cache = {
 		.inv_range = l2c210_inv_range,
 		.clean_range = l2c210_clean_range,
@@ -1067,6 +1083,7 @@ static const struct l2c_init_data of_l2c
 	.enable = l2c_enable,
 	.save = l2c_save,
 	.configure = l2c_configure,
+	.unlock = l2c_unlock,
 	.outer_cache = {
 		.inv_range   = l2c210_inv_range,
 		.clean_range = l2c210_clean_range,
@@ -1086,6 +1103,7 @@ static const struct l2c_init_data of_l2c
 	.enable = l2c220_enable,
 	.save = l2c_save,
 	.configure = l2c_configure,
+	.unlock = l2c220_unlock,
 	.outer_cache = {
 		.inv_range   = l2c220_inv_range,
 		.clean_range = l2c220_clean_range,
@@ -1213,6 +1231,7 @@ static const struct l2c_init_data of_l2c
 	.fixup = l2c310_fixup,
 	.save  = l2c310_save,
 	.configure = l2c310_configure,
+	.unlock = l2c310_unlock,
 	.outer_cache = {
 		.inv_range   = l2c210_inv_range,
 		.clean_range = l2c210_clean_range,
@@ -1242,6 +1261,7 @@ static const struct l2c_init_data of_l2c
 	.fixup = l2c310_fixup,
 	.save  = l2c310_save,
 	.configure = l2c310_configure,
+	.unlock = l2c310_unlock,
 	.outer_cache = {
 		.inv_range   = l2c210_inv_range,
 		.clean_range = l2c210_clean_range,
@@ -1419,6 +1439,7 @@ static const struct l2c_init_data of_aur
 	.fixup = aurora_fixup,
 	.save  = aurora_save,
 	.configure = l2c_configure,
+	.unlock = l2c_unlock,
 	.outer_cache = {
 		.inv_range   = aurora_inv_range,
 		.clean_range = aurora_clean_range,
@@ -1439,6 +1460,7 @@ static const struct l2c_init_data of_aur
 	.fixup = aurora_fixup,
 	.save  = aurora_save,
 	.configure = l2c_configure,
+	.unlock = l2c_unlock,
 	.outer_cache = {
 		.resume      = l2c_resume,
 	},
@@ -1589,6 +1611,7 @@ static const struct l2c_init_data of_bcm
 	.enable = l2c310_enable,
 	.save  = l2c310_save,
 	.configure = l2c310_configure,
+	.unlock = l2c310_unlock,
 	.outer_cache = {
 		.inv_range   = bcm_inv_range,
 		.clean_range = bcm_clean_range,
@@ -1626,6 +1649,7 @@ static const struct l2c_init_data of_tau
 	.enable = l2c_enable,
 	.save  = tauros3_save,
 	.configure = tauros3_configure,
+	.unlock = l2c_unlock,
 	/* Tauros3 broadcasts L1 cache operations to L2 */
 	.outer_cache = {
 		.resume      = l2c_resume,