From 6d132b2b09b476131855b9350ccad360e065d3fc Mon Sep 17 00:00:00 2001 From: Daniel Allred Date: Fri, 2 Sep 2016 00:40:21 -0500 Subject: [PATCH] arm: omap5: secure API for EMIF memory reservations 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 Reviewed-by: Tom Rini --- 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 3caba86791..0212df73c1 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 0000000000..33d4ea4eac --- /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, + * + * Daniel Allred + * Harinarayan Bhatta + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include +#include + +#include +#include +#include +#include +#include + +/* 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 842f2af8d1..4bde93f804 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_ */ -- 2.25.1