virt-dt: Allow reservation of secure region when in a RAM carveout
In this case the secure code lives in RAM, and hence the memory node in
the device tree needs to be adjusted. This avoids that the OS will map
and possibly access the reservation.
Add support for setting CONFIG_ARMV7_SECURE_RESERVE_SIZE to carve out
such a region. We only support cutting off memory from the beginning or
the end of a RAM bank as we do not want to increase their number (which
would happen if punching a hole) for simplicity reasons
This will be used in a subsequent patch for Jetson-TK1.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/cpu/armv7/virt-dt.c b/arch/arm/cpu/armv7/virt-dt.c
index caaaaab..32c368f 100644
--- a/arch/arm/cpu/armv7/virt-dt.c
+++ b/arch/arm/cpu/armv7/virt-dt.c
@@ -16,6 +16,7 @@
*/
#include <common.h>
+#include <errno.h>
#include <stdio_dev.h>
#include <linux/ctype.h>
#include <linux/types.h>
@@ -88,6 +89,34 @@
return 0;
}
+int armv7_apply_memory_carveout(u64 *start, u64 *size)
+{
+#ifdef CONFIG_ARMV7_SECURE_RESERVE_SIZE
+ if (*start + *size < CONFIG_ARMV7_SECURE_BASE ||
+ *start >= (u64)CONFIG_ARMV7_SECURE_BASE +
+ CONFIG_ARMV7_SECURE_RESERVE_SIZE)
+ return 0;
+
+ /* carveout must be at the beginning or the end of the bank */
+ if (*start == CONFIG_ARMV7_SECURE_BASE ||
+ *start + *size == (u64)CONFIG_ARMV7_SECURE_BASE +
+ CONFIG_ARMV7_SECURE_RESERVE_SIZE) {
+ if (*size < CONFIG_ARMV7_SECURE_RESERVE_SIZE) {
+ debug("Secure monitor larger than RAM bank!?\n");
+ return -EINVAL;
+ }
+ *size -= CONFIG_ARMV7_SECURE_RESERVE_SIZE;
+ if (*start == CONFIG_ARMV7_SECURE_BASE)
+ *start += CONFIG_ARMV7_SECURE_RESERVE_SIZE;
+ return 0;
+ }
+ debug("Secure monitor not located at beginning or end of RAM bank\n");
+ return -EINVAL;
+#else /* !CONFIG_ARMV7_SECURE_RESERVE_SIZE */
+ return 0;
+#endif
+}
+
int psci_update_dt(void *fdt)
{
#ifdef CONFIG_ARMV7_NONSEC