diff options
Diffstat (limited to 'services/spd/trusty/trusty.c')
-rw-r--r-- | services/spd/trusty/trusty.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/services/spd/trusty/trusty.c b/services/spd/trusty/trusty.c new file mode 100644 index 0000000..7daebcd --- /dev/null +++ b/services/spd/trusty/trusty.c @@ -0,0 +1,541 @@ +/* + * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2020, NVIDIA Corporation. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> +#include <inttypes.h> +#include <lib/xlat_tables/xlat_tables_v2.h> +#include <stdbool.h> +#include <stdint.h> +#include <string.h> + +#include <arch_helpers.h> +#include <bl31/bl31.h> +#include <bl31/interrupt_mgmt.h> +#include <common/bl_common.h> +#include <common/debug.h> +#include <common/runtime_svc.h> +#include <lib/el3_runtime/context_mgmt.h> +#include <lib/smccc.h> +#include <plat/common/platform.h> +#include <tools_share/uuid.h> + +#include "sm_err.h" +#include "smcall.h" + +/* Trusty UID: RFC-4122 compliant UUID version 4 */ +DEFINE_SVC_UUID2(trusty_uuid, + 0x40ee25f0, 0xa2bc, 0x304c, 0x8c, 0x4c, + 0xa1, 0x73, 0xc5, 0x7d, 0x8a, 0xf1); + +/* macro to check if Hypervisor is enabled in the HCR_EL2 register */ +#define HYP_ENABLE_FLAG 0x286001U + +/* length of Trusty's input parameters (in bytes) */ +#define TRUSTY_PARAMS_LEN_BYTES (4096U * 2) + +struct trusty_stack { + uint8_t space[PLATFORM_STACK_SIZE] __aligned(16); + uint32_t end; +}; + +struct trusty_cpu_ctx { + cpu_context_t cpu_ctx; + void *saved_sp; + uint32_t saved_security_state; + int32_t 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 smc_args { + uint64_t r0; + uint64_t r1; + uint64_t r2; + uint64_t r3; + uint64_t r4; + uint64_t r5; + uint64_t r6; + uint64_t r7; +}; + +static struct trusty_cpu_ctx trusty_cpu_ctx[PLATFORM_CORE_COUNT]; + +struct smc_args trusty_init_context_stack(void **sp, void *new_stack); +struct smc_args trusty_context_switch_helper(void **sp, void *smc_params); + +static uint32_t current_vmid; + +static struct trusty_cpu_ctx *get_trusty_ctx(void) +{ + return &trusty_cpu_ctx[plat_my_core_pos()]; +} + +static bool is_hypervisor_mode(void) +{ + uint64_t hcr = read_hcr(); + + return ((hcr & HYP_ENABLE_FLAG) != 0U) ? true : false; +} + +static struct smc_args trusty_context_switch(uint32_t security_state, uint64_t r0, + uint64_t r1, uint64_t r2, uint64_t r3) +{ + struct smc_args args, ret_args; + struct trusty_cpu_ctx *ctx = get_trusty_ctx(); + struct trusty_cpu_ctx *ctx_smc; + + assert(ctx->saved_security_state != security_state); + + args.r7 = 0; + if (is_hypervisor_mode()) { + /* According to the ARM DEN0028A spec, VMID is stored in x7 */ + ctx_smc = cm_get_context(NON_SECURE); + assert(ctx_smc != NULL); + args.r7 = SMC_GET_GP(ctx_smc, CTX_GPREG_X7); + } + /* r4, r5, r6 reserved for future use. */ + args.r6 = 0; + args.r5 = 0; + args.r4 = 0; + args.r3 = r3; + args.r2 = r2; + args.r1 = r1; + args.r0 = r0; + + /* + * To avoid the additional overhead in PSCI flow, skip FP context + * saving/restoring in case of CPU suspend and resume, assuming that + * when it's needed the PSCI caller has preserved FP context before + * going here. + */ + if (r0 != SMC_FC_CPU_SUSPEND && r0 != SMC_FC_CPU_RESUME) + fpregs_context_save(get_fpregs_ctx(cm_get_context(security_state))); + cm_el1_sysregs_context_save(security_state); + + ctx->saved_security_state = security_state; + ret_args = trusty_context_switch_helper(&ctx->saved_sp, &args); + + assert(ctx->saved_security_state == ((security_state == 0U) ? 1U : 0U)); + + cm_el1_sysregs_context_restore(security_state); + if (r0 != SMC_FC_CPU_SUSPEND && r0 != SMC_FC_CPU_RESUME) + fpregs_context_restore(get_fpregs_ctx(cm_get_context(security_state))); + + cm_set_next_eret_context(security_state); + + return ret_args; +} + +static uint64_t trusty_fiq_handler(uint32_t id, + uint32_t flags, + void *handle, + void *cookie) +{ + struct smc_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 != 0U) { + SMC_RET0(handle); + } + + if (ctx->fiq_handler_active != 0) { + INFO("%s: fiq handler already active\n", __func__); + SMC_RET0(handle); + } + + ctx->fiq_handler_active = 1; + (void)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_el1_sysregs_ctx(handle), CTX_SP_EL1); + + write_ctx_reg(get_el1_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_handler_sp); + cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_handler_pc, (uint32_t)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 >= (uint64_t)PLATFORM_CORE_COUNT) { + ERROR("%s: cpu %" PRId64 " >= %d\n", __func__, cpu, PLATFORM_CORE_COUNT); + return (uint64_t)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 smc_args ret; + struct trusty_cpu_ctx *ctx = get_trusty_ctx(); + + if (ctx->fiq_handler_active == 0) { + NOTICE("%s: fiq handler not active\n", __func__); + SMC_RET1(handle, (uint64_t)SM_ERR_INVALID_PARAMETERS); + } + + ret = trusty_context_switch(NON_SECURE, SMC_FC_FIQ_EXIT, 0, 0, 0); + if (ret.r0 != 1U) { + INFO("%s(%p) SMC_FC_FIQ_EXIT returned unexpected value, %" PRId64 "\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). + */ + (void)memcpy(get_gpregs_ctx(handle), &ctx->fiq_gpregs, sizeof(ctx->fiq_gpregs)); + ctx->fiq_handler_active = 0; + write_ctx_reg(get_el1_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_sp_el1); + cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_pc, (uint32_t)ctx->fiq_cpsr); + + SMC_RET0(handle); +} + +static uintptr_t trusty_smc_handler(uint32_t smc_fid, + u_register_t x1, + u_register_t x2, + u_register_t x3, + u_register_t x4, + void *cookie, + void *handle, + u_register_t flags) +{ + struct smc_args ret; + uint32_t vmid = 0U; + entry_point_info_t *ep_info = bl31_plat_get_next_image_ep_info(SECURE); + + /* + * Return success for SET_ROT_PARAMS if Trusty is not present, as + * Verified Boot is not even supported and returning success here + * would not compromise the boot process. + */ + if ((ep_info == NULL) && (smc_fid == SMC_YC_SET_ROT_PARAMS)) { + SMC_RET1(handle, 0); + } else if (ep_info == NULL) { + SMC_RET1(handle, SMC_UNK); + } else { + ; /* do nothing */ + } + + if (is_caller_secure(flags)) { + if (smc_fid == SMC_YC_NS_RETURN) { + ret = trusty_context_switch(SECURE, x1, 0, 0, 0); + SMC_RET8(handle, ret.r0, ret.r1, ret.r2, ret.r3, + ret.r4, ret.r5, ret.r6, ret.r7); + } + 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_GET_UUID: + case SMC_FC_GET_UUID: + /* provide the UUID for the service to the client */ + SMC_UUID_RET(handle, trusty_uuid); + break; + 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: + /* Not all OENs greater than SMC_ENTITY_SECURE_MONITOR are supported */ + if (SMC_ENTITY(smc_fid) > SMC_ENTITY_SECURE_MONITOR) { + VERBOSE("%s: unsupported SMC FID (0x%x)\n", __func__, smc_fid); + SMC_RET1(handle, SMC_UNK); + } + + if (is_hypervisor_mode()) + vmid = SMC_GET_GP(handle, CTX_GPREG_X7); + + if ((current_vmid != 0) && (current_vmid != vmid)) { + /* This message will cause SMC mechanism + * abnormal in multi-guest environment. + * Change it to WARN in case you need it. + */ + VERBOSE("Previous SMC not finished.\n"); + SMC_RET1(handle, SM_ERR_BUSY); + } + current_vmid = vmid; + ret = trusty_context_switch(NON_SECURE, smc_fid, x1, + x2, x3); + current_vmid = 0; + SMC_RET1(handle, ret.r0); + } + } +} + +static int32_t trusty_init(void) +{ + entry_point_info_t *ep_info; + struct smc_args zero_args = {0}; + struct trusty_cpu_ctx *ctx = get_trusty_ctx(); + uint32_t cpu = plat_my_core_pos(); + uint64_t reg_width = GET_RW(read_ctx_reg(get_el3state_ctx(&ctx->cpu_ctx), + CTX_SPSR_EL3)); + + /* + * Get information about the Trusty image. Its absence is a critical + * failure. + */ + ep_info = bl31_plat_get_next_image_ep_info(SECURE); + assert(ep_info != NULL); + + fpregs_context_save(get_fpregs_ctx(cm_get_context(NON_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 exception vectors + */ + if ((cpu != 0U) && (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); + fpregs_context_restore(get_fpregs_ctx(cm_get_context(SECURE))); + cm_set_next_eret_context(SECURE); + + ctx->saved_security_state = ~0U; /* initial saved state is invalid */ + (void)trusty_init_context_stack(&ctx->saved_sp, &ctx->secure_stack.end); + + (void)trusty_context_switch_helper(&ctx->saved_sp, &zero_args); + + cm_el1_sysregs_context_restore(NON_SECURE); + fpregs_context_restore(get_fpregs_ctx(cm_get_context(NON_SECURE))); + cm_set_next_eret_context(NON_SECURE); + + return 1; +} + +static void trusty_cpu_suspend(uint32_t off) +{ + struct smc_args ret; + + ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_SUSPEND, off, 0, 0); + if (ret.r0 != 0U) { + INFO("%s: cpu %d, SMC_FC_CPU_SUSPEND returned unexpected value, %" PRId64 "\n", + __func__, plat_my_core_pos(), ret.r0); + } +} + +static void trusty_cpu_resume(uint32_t on) +{ + struct smc_args ret; + + ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_RESUME, on, 0, 0); + if (ret.r0 != 0U) { + INFO("%s: cpu %d, SMC_FC_CPU_RESUME returned unexpected value, %" PRId64 "\n", + __func__, plat_my_core_pos(), ret.r0); + } +} + +static int32_t trusty_cpu_off_handler(u_register_t max_off_lvl) +{ + trusty_cpu_suspend(max_off_lvl); + + return 0; +} + +static void trusty_cpu_on_finish_handler(u_register_t max_off_lvl) +{ + struct trusty_cpu_ctx *ctx = get_trusty_ctx(); + + if (ctx->saved_sp == NULL) { + (void)trusty_init(); + } else { + trusty_cpu_resume(max_off_lvl); + } +} + +static void trusty_cpu_suspend_handler(u_register_t max_off_lvl) +{ + trusty_cpu_suspend(max_off_lvl); +} + +static void trusty_cpu_suspend_finish_handler(u_register_t max_off_lvl) +{ + trusty_cpu_resume(max_off_lvl); +} + +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, +}; + +void plat_trusty_set_boot_args(aapcs64_params_t *args); + +#if !defined(TSP_SEC_MEM_SIZE) && defined(BL32_MEM_SIZE) +#define TSP_SEC_MEM_SIZE BL32_MEM_SIZE +#endif + +#ifdef TSP_SEC_MEM_SIZE +#pragma weak plat_trusty_set_boot_args +void plat_trusty_set_boot_args(aapcs64_params_t *args) +{ + args->arg0 = TSP_SEC_MEM_SIZE; +} +#endif + +static int32_t trusty_setup(void) +{ + entry_point_info_t *ep_info; + uint32_t instr; + uint32_t flags; + int32_t ret; + bool aarch32 = false; + + /* Get trusty's entry point info */ + ep_info = bl31_plat_get_next_image_ep_info(SECURE); + if (ep_info == NULL) { + VERBOSE("Trusty image missing.\n"); + return -1; + } + + /* memmap first page of trusty's code memory before peeking */ + ret = mmap_add_dynamic_region(ep_info->pc, /* PA */ + ep_info->pc, /* VA */ + PAGE_SIZE, /* size */ + MT_SECURE | MT_RW_DATA); /* attrs */ + assert(ret == 0); + + /* peek into trusty's code to see if we have a 32-bit or 64-bit image */ + instr = *(uint32_t *)ep_info->pc; + + if (instr >> 24 == 0xeaU) { + INFO("trusty: Found 32 bit image\n"); + aarch32 = true; + } else if (instr >> 8 == 0xd53810U || instr >> 16 == 0x9400U) { + INFO("trusty: Found 64 bit image\n"); + } else { + ERROR("trusty: Found unknown image, 0x%x\n", instr); + return -1; + } + + /* unmap trusty's memory page */ + (void)mmap_remove_dynamic_region(ep_info->pc, PAGE_SIZE); + + 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); + (void)memset(&ep_info->args, 0, sizeof(ep_info->args)); + plat_trusty_set_boot_args(&ep_info->args); + + /* register init handler */ + bl31_register_bl32_init(trusty_init); + + /* register power management hooks */ + psci_register_spd_pm_hook(&trusty_pm); + + /* register interrupt handler */ + flags = 0; + set_interrupt_rm_flag(flags, NON_SECURE); + ret = register_interrupt_type_handler(INTR_TYPE_S_EL1, + trusty_fiq_handler, + flags); + if (ret != 0) { + VERBOSE("trusty: failed to register fiq handler, ret = %d\n", ret); + } + + if (aarch32) { + entry_point_info_t *ns_ep_info; + uint32_t spsr; + + ns_ep_info = bl31_plat_get_next_image_ep_info(NON_SECURE); + if (ns_ep_info == NULL) { + NOTICE("Trusty: non-secure image missing.\n"); + return -1; + } + spsr = ns_ep_info->spsr; + if (GET_RW(spsr) == MODE_RW_64 && GET_EL(spsr) == MODE_EL2) { + spsr &= ~(MODE_EL_MASK << MODE_EL_SHIFT); + spsr |= MODE_EL1 << MODE_EL_SHIFT; + } + if (GET_RW(spsr) == MODE_RW_32 && GET_M32(spsr) == MODE32_hyp) { + spsr &= ~(MODE32_MASK << MODE32_SHIFT); + spsr |= MODE32_svc << MODE32_SHIFT; + } + if (spsr != ns_ep_info->spsr) { + NOTICE("Trusty: Switch bl33 from EL2 to EL1 (spsr 0x%x -> 0x%x)\n", + ns_ep_info->spsr, spsr); + ns_ep_info->spsr = spsr; + } + } + + return 0; +} + +/* Define a SPD runtime service descriptor for fast SMC calls */ +DECLARE_RT_SVC( + trusty_fast, + + OEN_TOS_START, + OEN_TOS_END, + SMC_TYPE_FAST, + trusty_setup, + trusty_smc_handler +); + +/* Define a SPD runtime service descriptor for yielding SMC calls */ +DECLARE_RT_SVC( + trusty_std, + + OEN_TAP_START, + SMC_ENTITY_SECURE_MONITOR, + SMC_TYPE_YIELD, + NULL, + trusty_smc_handler +); |