Juno: clear DMA-330 SMMU security state
By default the SMMU for the DMA-330 is configured to mark some stream IDs
as always belonging to the Secure world. As a result, if EL1 software turns
the SMMU on, certain Non-Secure accesses get rewritten as Secure, making
them bypass translation and access Secure physical addresses directly.
Since the current Juno board firmware configures the DMA-330 hardware as
Non-Secure, rewrite the SMMU's default SSD table as well to prevent any
unexpected behaviour in EL1.
Change-Id: Iaa81d883eecf28d80eb182b9ce475684bf9c718c
diff --git a/plat/juno/plat_security.c b/plat/juno/plat_security.c
index 64e493f..254357d 100644
--- a/plat/juno/plat_security.c
+++ b/plat/juno/plat_security.c
@@ -29,6 +29,7 @@
*/
#include <debug.h>
+#include <mmio.h>
#include <tzc400.h>
#include "juno_def.h"
@@ -94,6 +95,19 @@
}
/*******************************************************************************
+ * Set up the MMU-401 SSD tables. The power-on configuration has all stream IDs
+ * assigned to Non-Secure except some for the DMA-330. Assign those back to the
+ * Non-Secure world as well, otherwise EL1 may end up erroneously generating
+ * (untranslated) Secure transactions if it turns the SMMU on.
+ ******************************************************************************/
+static void init_mmu401(void)
+{
+ uint32_t reg = mmio_read_32(MMU401_DMA330_BASE + MMU401_SSD_OFFSET);
+ reg |= 0x1FF;
+ mmio_write_32(MMU401_DMA330_BASE + MMU401_SSD_OFFSET, reg);
+}
+
+/*******************************************************************************
* Initialize the secure environment. At this moment only the TrustZone
* Controller is initialized.
******************************************************************************/
@@ -101,4 +115,6 @@
{
/* Initialize the TrustZone Controller */
init_tzc400();
+ /* Initialize the SMMU SSD tables*/
+ init_mmu401();
}