[PATCH 2/2] ARM: at91: setup outer cache .write_sec() callback if needed

From: Clément Léger
Date: Mon Jun 06 2022 - 10:58:26 EST


When running under OP-TEE, the L2 cache is configured by OP-TEE and the
sam platform code does not allow any modification yet. Setup a dummy
.write_sec() callback to avoid triggering exceptions when Linux tries
to modify the L2 cache configuration.

Signed-off-by: Clément Léger <clement.leger@xxxxxxxxxxx>
---
arch/arm/mach-at91/sama5.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/arch/arm/mach-at91/sama5.c b/arch/arm/mach-at91/sama5.c
index de5dd28b392e..d1a9e940a785 100644
--- a/arch/arm/mach-at91/sama5.c
+++ b/arch/arm/mach-at91/sama5.c
@@ -9,13 +9,27 @@
#include <linux/of.h>
#include <linux/of_platform.h>

+#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
+#include <asm/outercache.h>
#include <asm/system_misc.h>

#include "generic.h"
#include "sam_secure.h"

+static void sama5_l2c310_write_sec(unsigned long val, unsigned reg)
+{
+ /* OP-TEE configures the L2 cache and does not allow modifying it yet */
+}
+
+static void __init sama5_secure_cache_init(void)
+{
+ sam_secure_init();
+ if (sam_linux_is_in_normal_world())
+ outer_cache.write_sec = sama5_l2c310_write_sec;
+}
+
static void __init sama5_dt_device_init(void)
{
of_platform_default_populate(NULL, NULL, NULL);
@@ -30,6 +44,7 @@ static const char *const sama5_dt_board_compat[] __initconst = {
DT_MACHINE_START(sama5_dt, "Atmel SAMA5")
/* Maintainer: Atmel */
.init_machine = sama5_dt_device_init,
+ .init_early = sama5_secure_cache_init,
.dt_compat = sama5_dt_board_compat,
MACHINE_END

@@ -41,6 +56,7 @@ static const char *const sama5_alt_dt_board_compat[] __initconst = {
DT_MACHINE_START(sama5_alt_dt, "Atmel SAMA5")
/* Maintainer: Atmel */
.init_machine = sama5_dt_device_init,
+ .init_early = sama5_secure_cache_init,
.dt_compat = sama5_alt_dt_board_compat,
.l2c_aux_mask = ~0UL,
MACHINE_END
@@ -60,6 +76,7 @@ static const char *const sama5d2_compat[] __initconst = {
DT_MACHINE_START(sama5d2, "Atmel SAMA5")
/* Maintainer: Atmel */
.init_machine = sama5d2_init,
+ .init_early = sama5_secure_cache_init,
.dt_compat = sama5d2_compat,
.l2c_aux_mask = ~0UL,
MACHINE_END
--
2.36.1