[PATCH] ARM: sti: Implement dummy L2 cache's write_sec

[PATCH] ARM: sti: Implement dummy L2 cache's write_sec

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@st.com>

This patch implements the write_sec callback that handle PL310
secure registers writes.
This callback is just a stub for now, to avoid system crash.
Later, it could handle SMC calls so that TZ handles the needed writes.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---
 arch/arm/mach-sti/board-dt.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/mach-sti/board-dt.c b/arch/arm/mach-sti/board-dt.c
index cfee0ef..e04cd1b 100644
--- a/arch/arm/mach-sti/board-dt.c
+++ b/arch/arm/mach-sti/board-dt.c
@@ -23,6 +23,14 @@ static const char *const stih41x_dt_match[] __initconst = {
 	NULL
 };
 
+static void sti_l2_write_sec(unsigned long val, unsigned reg)
+{
+	/*
+	 * We can't write to secure registers as we are in non-secure
+	 * mode, until we have some SMI service available.
+	 */
+}
+
 DT_MACHINE_START(STM, "STi SoC with Flattened Device Tree")
 	.dt_compat	= stih41x_dt_match,
 	.l2c_aux_val	= L2C_AUX_CTRL_SHARED_OVERRIDE |
@@ -31,4 +39,5 @@ DT_MACHINE_START(STM, "STi SoC with Flattened Device Tree")
 			  L2C_AUX_CTRL_WAY_SIZE(4),
 	.l2c_aux_mask	= 0xc0000fff,
 	.smp		= smp_ops(sti_smp_ops),
+	.l2c_write_sec	= sti_l2_write_sec,
 MACHINE_END
-- 
1.9.1

Re: [PATCH] ARM: sti: Implement dummy L2 cache's write_sec

[Russell King - ARM Linux]

On Tue, Jun 28, 2016 at 11:40:37AM +0200, patrice.chotard@st.com wrote:
> From: Patrice Chotard <patrice.chotard@st.com>
> 
> This patch implements the write_sec callback that handle PL310
> secure registers writes.
> This callback is just a stub for now, to avoid system crash.
> Later, it could handle SMC calls so that TZ handles the needed writes.

Is there much point having the L2 cache DT node enabled if you have
no support for the writes, which are required for the hardware to be
enabled?

-- 
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Re: [PATCH] ARM: sti: Implement dummy L2 cache's write_sec

[Patrice Chotard]

Hi Russell

On 06/28/2016 11:49 AM, Russell King - ARM Linux wrote:
> On Tue, Jun 28, 2016 at 11:40:37AM +0200, patrice.chotard@st.com wrote:
>> From: Patrice Chotard <patrice.chotard@st.com>
>>
>> This patch implements the write_sec callback that handle PL310
>> secure registers writes.
>> This callback is just a stub for now, to avoid system crash.
>> Later, it could handle SMC calls so that TZ handles the needed writes.
> Is there much point having the L2 cache DT node enabled if you have
> no support for the writes, which are required for the hardware to be
> enabled?
>
It's similar to what has been done for ux500 machine, in non secure 
mode, we
can't write in L2 cache secure registers.

Patrice