[U-Boot] [PATCH 2/5] arm: omap5: secure API for EMIF memory reservations

Daniel Allred
2016-09-02T05:40:21Z

Create a few public APIs which rely on secure world ROM/HAL
APIs for their implementation. These are intended to be used
to reserve a portion of the EMIF memory and configure hardware
firewalls around that region to prevent public code from
manipulating or interfering with that memory.

Signed-off-by: Daniel Allred <d-allred@ti.com>
---
arch/arm/cpu/armv7/omap5/Makefile | 1 +
arch/arm/cpu/armv7/omap5/sec-fxns.c | 126 +++++++++++++++++++++++++++++++++
arch/arm/include/asm/omap_sec_common.h | 24 +++++++
3 files changed, 151 insertions(+)
create mode 100644 arch/arm/cpu/armv7/omap5/sec-fxns.c

diff --git a/arch/arm/cpu/armv7/omap5/Makefile b/arch/arm/cpu/armv7/omap5/Makefile
index 3caba86..0212df7 100644
--- a/arch/arm/cpu/armv7/omap5/Makefile
+++ b/arch/arm/cpu/armv7/omap5/Makefile
@@ -14,3 +14,4 @@ obj-y += hw_data.o
obj-y += abb.o
obj-y += fdt.o
obj-$(CONFIG_IODELAY_RECALIBRATION) += dra7xx_iodelay.o
+obj-$(CONFIG_TI_SECURE_DEVICE) += sec-fxns.o
diff --git a/arch/arm/cpu/armv7/omap5/sec-fxns.c b/arch/arm/cpu/armv7/omap5/sec-fxns.c
new file mode 100644
index 0000000..33d4ea4
--- /dev/null
+++ b/arch/arm/cpu/armv7/omap5/sec-fxns.c
@@ -0,0 +1,126 @@
+/*
+ *
+ * Security related functions for OMAP5 class devices
+ *
+ * (C) Copyright 2016
+ * Texas Instruments, <www.ti.com>
+ *
+ * Daniel Allred <d-allred@ti.com>
+ * Harinarayan Bhatta <harinarayan@ti.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <stdarg.h>
+
+#include <asm/arch/sys_proto.h>
+#include <asm/omap_common.h>
+#include <asm/omap_sec_common.h>
+#include <asm/spl.h>
+#include <spl.h>
+
+/* Index for signature PPA-based TI HAL APIs */
+#define PPA_HAL_SERVICES_START_INDEX (0x200)
+#define PPA_SERV_HAL_SETUP_SEC_RESVD_REGION (PPA_HAL_SERVICES_START_INDEX + 25)
+#define PPA_SERV_HAL_SETUP_EMIF_FW_REGION (PPA_HAL_SERVICES_START_INDEX + 26)
+#define PPA_SERV_HAL_LOCK_EMIF_FW (PPA_HAL_SERVICES_START_INDEX + 27)
+
+static u32 get_sec_mem_start(void)
+{
+ u32 sec_mem_start = CONFIG_TI_SECURE_EMIF_REGION_START;
+ u32 sec_mem_size = CONFIG_TI_SECURE_EMIF_TOTAL_REGION_SIZE;
+ /*
+ * Total reserved region is all contiguous with protected
+ * region coming first, followed by the non-secure region.
+ * If 0x0 start address is given, we simply put the reserved
+ * region at the end of the external DRAM.
+ */
+ if (sec_mem_start == 0)
+ sec_mem_start =
+ (CONFIG_SYS_SDRAM_BASE +
+ (omap_sdram_size() - sec_mem_size));
+ return sec_mem_start;
+}
+
+int secure_emif_firewall_setup(uint8_t region_num, uint32_t start_addr,
+ uint32_t size, uint32_t access_perm,
+ uint32_t initiator_perm)
+{
+ int result = 1;
+
+ /*
+ * Call PPA HAL API to do any other general firewall
+ * configuration for regions 1-6 of the EMIF firewall.
+ */
+ debug("%s: regionNum = %x, startAddr = %x, size = %x", __func__,
+ region_num, start_addr, size);
+
+ result = secure_rom_call(
+ PPA_SERV_HAL_SETUP_EMIF_FW_REGION, 0, 0, 4,
+ (start_addr & 0xFFFFFFF0) | (region_num & 0x0F),
+ size, access_perm, initiator_perm);
+
+ if (result != 0) {
+ puts("Secure EMIF Firewall Setup failed!\n");
+ debug("Return Value = %x\n", result);
+ }
+
+ return result;
+}
+
+#if (CONFIG_TI_SECURE_EMIF_TOTAL_REGION_SIZE < \
+ CONFIG_TI_SECURE_EMIF_PROTECTED_REGION_SIZE)
+#error "TI Secure EMIF: Protected size cannot be larger than total size."
+#endif
+int secure_emif_reserve(void)
+{
+ int result = 1;
+ u32 sec_mem_start = get_sec_mem_start();
+ u32 sec_prot_size = CONFIG_TI_SECURE_EMIF_PROTECTED_REGION_SIZE;
+
+ /* If there is no protected region, there is no reservation to make */
+ if (sec_prot_size == 0)
+ return 0;
+
+ /*
+ * Call PPA HAL API to reserve a chunk of EMIF SDRAM
+ * for secure world use. This region should be carved out
+ * from use by any public code. EMIF firewall region 7
+ * will be used to protect this block of memory.
+ */
+ result = secure_rom_call(
+ PPA_SERV_HAL_SETUP_SEC_RESVD_REGION,
+ 0, 0, 2, sec_mem_start, sec_prot_size);
+
+ if (result != 0) {
+ puts("SDRAM Firewall: Secure memory reservation failed!\n");
+ debug("Return Value = %x\n", result);
+ }
+
+ return result;
+}
+
+int secure_emif_firewall_lock(void)
+{
+ int result = 1;
+
+ /*
+ * Call PPA HAL API to lock the EMIF firewall configurations.
+ * After this API is called, none of the PPA HAL APIs for
+ * configuring the EMIF firewalls will be usable again (that
+ * is, calls to those APIs will return failure and have no
+ * effect).
+ */
+
+ result = secure_rom_call(
+ PPA_SERV_HAL_LOCK_EMIF_FW,
+ 0, 0, 0);
+
+ if (result != 0) {
+ puts("Secure EMIF Firewall Lock failed!\n");
+ debug("Return Value = %x\n", result);
+ }
+
+ return result;
+}
diff --git a/arch/arm/include/asm/omap_sec_common.h b/arch/arm/include/asm/omap_sec_common.h
index 842f2af..4bde93f 100644
--- a/arch/arm/include/asm/omap_sec_common.h
+++ b/arch/arm/include/asm/omap_sec_common.h
@@ -27,4 +27,28 @@ u32 secure_rom_call(u32 service, u32 proc_id, u32 flag, ...);
*/
int secure_boot_verify_image(void **p_image, size_t *p_size);

+/*
+ * Invoke a secure HAL API that allows configuration of the external memory
+ * firewall regions.
+ */
+int secure_emif_firewall_setup(uint8_t region_num, uint32_t start_addr,
+ uint32_t size, uint32_t access_perm,
+ uint32_t initiator_perm);
+
+/*
+ * Invoke a secure HAL API on high-secure (HS) device variants that reserves a
+ * region of external memory for secure world use, and protects it using memory
+ * firewalls that prevent public world access. This API is intended to setaside
+ * memory that will be used for a secure world OS/TEE.
+ */
+int secure_emif_reserve(void);
+
+/*
+ * Invoke a secure HAL API to lock the external memory firewall configurations.
+ * After this API is called, none of the HAL APIs for configuring the that
+ * firewall will be usable (calls to those APIs will return failure and have
+ * no effect).
+ */
+int secure_emif_firewall_lock(void);
+
#endif /* _OMAP_SEC_COMMON_H_ */
--
2.7.4