spd: dispatcher for interacting with the Trusty TEE
This patch adds the secure payload dispatcher for interacting
with Google's Trusty TEE. Documentation for Trusty can be found
at https://source.android.com/security/trusty
Original authors:
-----------------
* Arve Hjønnevåg <arve@android.com>
* Michael Ryleev <gmar@google.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/services/spd/trusty/trusty.c b/services/spd/trusty/trusty.c
new file mode 100644
index 0000000..4962d44
--- /dev/null
+++ b/services/spd/trusty/trusty.c
@@ -0,0 +1,400 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <bl_common.h>
+#include <bl31.h>
+#include <context_mgmt.h>
+#include <debug.h>
+#include <interrupt_mgmt.h>
+#include <platform.h>
+#include <runtime_svc.h>
+#include <string.h>
+
+#include "smcall.h"
+#include "sm_err.h"
+
+struct trusty_stack {
+ uint8_t space[PLATFORM_STACK_SIZE] __aligned(16);
+};
+
+struct trusty_cpu_ctx {
+ cpu_context_t cpu_ctx;
+ void *saved_sp;
+ uint32_t saved_security_state;
+ int fiq_handler_active;
+ uint64_t fiq_handler_pc;
+ uint64_t fiq_handler_cpsr;
+ uint64_t fiq_handler_sp;
+ uint64_t fiq_pc;
+ uint64_t fiq_cpsr;
+ uint64_t fiq_sp_el1;
+ gp_regs_t fiq_gpregs;
+ struct trusty_stack secure_stack;
+};
+
+struct args {
+ uint64_t r0;
+ uint64_t r1;
+ uint64_t r2;
+ uint64_t r3;
+};
+
+struct trusty_cpu_ctx trusty_cpu_ctx[PLATFORM_CORE_COUNT];
+
+struct args trusty_init_context_stack(void **sp, void *new_stack);
+struct args trusty_context_switch_helper(void **sp, uint64_t r0, uint64_t r1,
+ uint64_t r2, uint64_t r3);
+
+static struct trusty_cpu_ctx *get_trusty_ctx(void)
+{
+ return &trusty_cpu_ctx[plat_my_core_pos()];
+}
+
+static struct args trusty_context_switch(uint32_t security_state, uint64_t r0,
+ uint64_t r1, uint64_t r2, uint64_t r3)
+{
+ struct args ret;
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+ assert(ctx->saved_security_state != security_state);
+
+ cm_el1_sysregs_context_save(security_state);
+
+ ctx->saved_security_state = security_state;
+ ret = trusty_context_switch_helper(&ctx->saved_sp, r0, r1, r2, r3);
+
+ assert(ctx->saved_security_state == !security_state);
+
+ cm_el1_sysregs_context_restore(security_state);
+ cm_set_next_eret_context(security_state);
+
+ return ret;
+}
+
+static uint64_t trusty_fiq_handler(uint32_t id,
+ uint32_t flags,
+ void *handle,
+ void *cookie)
+{
+ struct args ret;
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+ assert(!is_caller_secure(flags));
+
+ ret = trusty_context_switch(NON_SECURE, SMC_FC_FIQ_ENTER, 0, 0, 0);
+ if (ret.r0) {
+ SMC_RET0(handle);
+ }
+
+ if (ctx->fiq_handler_active) {
+ INFO("%s: fiq handler already active\n", __func__);
+ SMC_RET0(handle);
+ }
+
+ ctx->fiq_handler_active = 1;
+ memcpy(&ctx->fiq_gpregs, get_gpregs_ctx(handle), sizeof(ctx->fiq_gpregs));
+ ctx->fiq_pc = SMC_GET_EL3(handle, CTX_ELR_EL3);
+ ctx->fiq_cpsr = SMC_GET_EL3(handle, CTX_SPSR_EL3);
+ ctx->fiq_sp_el1 = read_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1);
+
+ write_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_handler_sp);
+ cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_handler_pc, ctx->fiq_handler_cpsr);
+
+ SMC_RET0(handle);
+}
+
+static uint64_t trusty_set_fiq_handler(void *handle, uint64_t cpu,
+ uint64_t handler, uint64_t stack)
+{
+ struct trusty_cpu_ctx *ctx;
+
+ if (cpu >= PLATFORM_CORE_COUNT) {
+ ERROR("%s: cpu %ld >= %d\n", __func__, cpu, PLATFORM_CORE_COUNT);
+ return SM_ERR_INVALID_PARAMETERS;
+ }
+
+ ctx = &trusty_cpu_ctx[cpu];
+ ctx->fiq_handler_pc = handler;
+ ctx->fiq_handler_cpsr = SMC_GET_EL3(handle, CTX_SPSR_EL3);
+ ctx->fiq_handler_sp = stack;
+
+ SMC_RET1(handle, 0);
+}
+
+static uint64_t trusty_get_fiq_regs(void *handle)
+{
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+ uint64_t sp_el0 = read_ctx_reg(&ctx->fiq_gpregs, CTX_GPREG_SP_EL0);
+
+ SMC_RET4(handle, ctx->fiq_pc, ctx->fiq_cpsr, sp_el0, ctx->fiq_sp_el1);
+}
+
+static uint64_t trusty_fiq_exit(void *handle, uint64_t x1, uint64_t x2, uint64_t x3)
+{
+ struct args ret;
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+ if (!ctx->fiq_handler_active) {
+ NOTICE("%s: fiq handler not active\n", __func__);
+ SMC_RET1(handle, SM_ERR_INVALID_PARAMETERS);
+ }
+
+ ret = trusty_context_switch(NON_SECURE, SMC_FC_FIQ_EXIT, 0, 0, 0);
+ if (ret.r0 != 1) {
+ INFO("%s(%p) SMC_FC_FIQ_EXIT returned unexpected value, %ld\n",
+ __func__, handle, ret.r0);
+ }
+
+ /*
+ * Restore register state to state recorded on fiq entry.
+ *
+ * x0, sp_el1, pc and cpsr need to be restored because el1 cannot
+ * restore them.
+ *
+ * x1-x4 and x8-x17 need to be restored here because smc_handler64
+ * corrupts them (el1 code also restored them).
+ */
+ memcpy(get_gpregs_ctx(handle), &ctx->fiq_gpregs, sizeof(ctx->fiq_gpregs));
+ ctx->fiq_handler_active = 0;
+ write_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_sp_el1);
+ cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_pc, ctx->fiq_cpsr);
+
+ SMC_RET0(handle);
+}
+
+static uint64_t trusty_smc_handler(uint32_t smc_fid,
+ uint64_t x1,
+ uint64_t x2,
+ uint64_t x3,
+ uint64_t x4,
+ void *cookie,
+ void *handle,
+ uint64_t flags)
+{
+ struct args ret;
+
+ if (is_caller_secure(flags)) {
+ if (smc_fid == SMC_SC_NS_RETURN) {
+ ret = trusty_context_switch(SECURE, x1, 0, 0, 0);
+ SMC_RET4(handle, ret.r0, ret.r1, ret.r2, ret.r3);
+ }
+ INFO("%s (0x%x, 0x%lx, 0x%lx, 0x%lx, 0x%lx, %p, %p, 0x%lx) \
+ cpu %d, unknown smc\n",
+ __func__, smc_fid, x1, x2, x3, x4, cookie, handle, flags,
+ plat_my_core_pos());
+ SMC_RET1(handle, SMC_UNK);
+ } else {
+ switch (smc_fid) {
+ case SMC_FC64_SET_FIQ_HANDLER:
+ return trusty_set_fiq_handler(handle, x1, x2, x3);
+ case SMC_FC64_GET_FIQ_REGS:
+ return trusty_get_fiq_regs(handle);
+ case SMC_FC_FIQ_EXIT:
+ return trusty_fiq_exit(handle, x1, x2, x3);
+ default:
+ ret = trusty_context_switch(NON_SECURE, smc_fid, x1,
+ x2, x3);
+ SMC_RET1(handle, ret.r0);
+ }
+ }
+}
+
+static int32_t trusty_init(void)
+{
+ void el3_exit();
+ entry_point_info_t *ep_info;
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+ uint32_t cpu = plat_my_core_pos();
+ int reg_width = GET_RW(read_ctx_reg(get_el3state_ctx(&ctx->cpu_ctx),
+ CTX_SPSR_EL3));
+
+ ep_info = bl31_plat_get_next_image_ep_info(SECURE);
+
+ cm_el1_sysregs_context_save(NON_SECURE);
+
+ cm_set_context(&ctx->cpu_ctx, SECURE);
+ cm_init_my_context(ep_info);
+
+ /*
+ * Adjust secondary cpu entry point for 32 bit images to the
+ * end of exeption vectors
+ */
+ if ((cpu != 0) && (reg_width == MODE_RW_32)) {
+ INFO("trusty: cpu %d, adjust entry point to 0x%lx\n",
+ cpu, ep_info->pc + (1U << 5));
+ cm_set_elr_el3(SECURE, ep_info->pc + (1U << 5));
+ }
+
+ cm_el1_sysregs_context_restore(SECURE);
+ cm_set_next_eret_context(SECURE);
+
+ ctx->saved_security_state = ~0; /* initial saved state is invalid */
+ trusty_init_context_stack(&ctx->saved_sp, &ctx->secure_stack);
+
+ trusty_context_switch_helper(&ctx->saved_sp, 0, 0, 0, 0);
+
+ cm_el1_sysregs_context_restore(NON_SECURE);
+ cm_set_next_eret_context(NON_SECURE);
+
+ return 0;
+}
+
+static void trusty_cpu_suspend(void)
+{
+ struct args ret;
+ unsigned int linear_id = plat_my_core_pos();
+
+ ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_SUSPEND, 0, 0, 0);
+ if (ret.r0 != 0) {
+ INFO("%s: cpu %d, SMC_FC_CPU_SUSPEND returned unexpected value, %ld\n",
+ __func__, linear_id, ret.r0);
+ }
+}
+
+static void trusty_cpu_resume(void)
+{
+ struct args ret;
+ unsigned int linear_id = plat_my_core_pos();
+
+ ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_RESUME, 0, 0, 0);
+ if (ret.r0 != 0) {
+ INFO("%s: cpu %d, SMC_FC_CPU_RESUME returned unexpected value, %ld\n",
+ __func__, linear_id, ret.r0);
+ }
+}
+
+static int32_t trusty_cpu_off_handler(uint64_t unused)
+{
+ trusty_cpu_suspend();
+
+ return 0;
+}
+
+static void trusty_cpu_on_finish_handler(uint64_t unused)
+{
+ struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+ if (!ctx->saved_sp) {
+ trusty_init();
+ } else {
+ trusty_cpu_resume();
+ }
+}
+
+static void trusty_cpu_suspend_handler(uint64_t unused)
+{
+ trusty_cpu_suspend();
+}
+
+static void trusty_cpu_suspend_finish_handler(uint64_t unused)
+{
+ trusty_cpu_resume();
+}
+
+static const spd_pm_ops_t trusty_pm = {
+ .svc_off = trusty_cpu_off_handler,
+ .svc_suspend = trusty_cpu_suspend_handler,
+ .svc_on_finish = trusty_cpu_on_finish_handler,
+ .svc_suspend_finish = trusty_cpu_suspend_finish_handler,
+};
+
+static int32_t trusty_setup(void)
+{
+ entry_point_info_t *ep_info;
+ uint32_t instr;
+ uint32_t flags;
+ int ret;
+ int aarch32 = 0;
+
+ ep_info = bl31_plat_get_next_image_ep_info(SECURE);
+ if (!ep_info) {
+ INFO("Trusty image missing.\n");
+ return -1;
+ }
+
+ instr = *(uint32_t *)ep_info->pc;
+
+ if (instr >> 24 == 0xea) {
+ INFO("trusty: Found 32 bit image\n");
+ aarch32 = 1;
+ } else if (instr >> 8 == 0xd53810) {
+ INFO("trusty: Found 64 bit image\n");
+ } else {
+ INFO("trusty: Found unknown image, 0x%x\n", instr);
+ }
+
+ SET_PARAM_HEAD(ep_info, PARAM_EP, VERSION_1, SECURE | EP_ST_ENABLE);
+ if (!aarch32)
+ ep_info->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
+ DISABLE_ALL_EXCEPTIONS);
+ else
+ ep_info->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM,
+ SPSR_E_LITTLE,
+ DAIF_FIQ_BIT |
+ DAIF_IRQ_BIT |
+ DAIF_ABT_BIT);
+
+ bl31_register_bl32_init(trusty_init);
+
+ psci_register_spd_pm_hook(&trusty_pm);
+
+ flags = 0;
+ set_interrupt_rm_flag(flags, NON_SECURE);
+ ret = register_interrupt_type_handler(INTR_TYPE_S_EL1,
+ trusty_fiq_handler,
+ flags);
+ if (ret)
+ ERROR("trusty: failed to register fiq handler, ret = %d\n", ret);
+
+ return 0;
+}
+
+/* Define a SPD runtime service descriptor for fast SMC calls */
+DECLARE_RT_SVC(
+ trusty_fast,
+
+ OEN_TOS_START,
+ SMC_ENTITY_SECURE_MONITOR,
+ SMC_TYPE_FAST,
+ trusty_setup,
+ trusty_smc_handler
+);
+
+/* Define a SPD runtime service descriptor for standard SMC calls */
+DECLARE_RT_SVC(
+ trusty_std,
+
+ OEN_TOS_START,
+ SMC_ENTITY_SECURE_MONITOR,
+ SMC_TYPE_STD,
+ NULL,
+ trusty_smc_handler
+);