/*
* Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
/*******************************************************************************
* This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a
* plug-in component to the Secure Monitor, registered as a runtime service. The
* SPD is expected to be a functional extension of the Secure Payload (SP) that
* executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting
* the Trusted OS/Applications range to the dispatcher. The SPD will either
* handle the request locally or delegate it to the Secure Payload. It is also
* responsible for initialising and maintaining communication with the SP.
******************************************************************************/
#include <arch_helpers.h>
#include <assert.h>
#include <bl31.h>
#include <bl_common.h>
#include <context_mgmt.h>
#include <debug.h>
#include <errno.h>
#include <platform.h>
#include <runtime_svc.h>
#include <stddef.h>
#include <tlk.h>
#include <uuid.h>
#include "tlkd_private.h"
extern const spd_pm_ops_t tlkd_pm_ops;
/*******************************************************************************
* Per-cpu Secure Payload state
******************************************************************************/
tlk_context_t tlk_ctx;
/*******************************************************************************
* CPU number on which TLK booted up
******************************************************************************/
static uint32_t boot_cpu;
/* TLK UID: RFC-4122 compliant UUID (version-5, sha-1) */
DEFINE_SVC_UUID(tlk_uuid,
0xbd11e9c9, 0x2bba, 0x52ee, 0xb1, 0x72,
0x46, 0x1f, 0xba, 0x97, 0x7f, 0x63);
int32_t tlkd_init(void);
/*******************************************************************************
* Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
* (aarch32/aarch64) if not already known and initialises the context for entry
* into the SP for its initialisation.
******************************************************************************/
int32_t tlkd_setup(void)
{
entry_point_info_t *tlk_ep_info;
/*
* Get information about the Secure Payload (BL32) image. Its
* absence is a critical failure.
*/
tlk_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
if (!tlk_ep_info) {
WARN("No SP provided. Booting device without SP"
" initialization. SMC`s destined for SP"
" will return SMC_UNK\n");
return 1;
}
/*
* If there's no valid entry point for SP, we return a non-zero value
* signalling failure initializing the service. We bail out without
* registering any handlers
*/
if (!tlk_ep_info->pc)
return 1;
/*
* Inspect the SP image's SPSR and determine it's execution state
* i.e whether AArch32 or AArch64.
*/
tlkd_init_tlk_ep_state(tlk_ep_info,
(tlk_ep_info->spsr >> MODE_RW_SHIFT) & MODE_RW_MASK,
tlk_ep_info->pc,
&tlk_ctx);
/*
* All TLK SPD initialization done. Now register our init function
* with BL31 for deferred invocation
*/
bl31_register_bl32_init(&tlkd_init);
return 0;
}
/*******************************************************************************
* This function passes control to the Secure Payload image (BL32) for the first
* time on the primary cpu after a cold boot. It assumes that a valid secure
* context has already been created by tlkd_setup() which can be directly
* used. This function performs a synchronous entry into the Secure payload.
* The SP passes control back to this routine through a SMC.
******************************************************************************/
int32_t tlkd_init(void)
{
entry_point_info_t *tlk_entry_point;
/*
* Get information about the Secure Payload (BL32) image. Its
* absence is a critical failure.
*/
tlk_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
assert(tlk_entry_point);
cm_init_my_context(tlk_entry_point);
/*
* TLK runs only on a single CPU. Store the value of the boot
* CPU for sanity checking later.
*/
boot_cpu = plat_my_core_pos();
/*
* Arrange for an entry into the test secure payload.
*/
return tlkd_synchronous_sp_entry(&tlk_ctx);
}
/*******************************************************************************
* This function is responsible for handling all SMCs in the Trusted OS/App
* range from the non-secure state as defined in the SMC Calling Convention
* Document. It is also responsible for communicating with the Secure payload
* to delegate work and return results back to the non-secure state. Lastly it
* will also return any information that the secure payload needs to do the
* work assigned to it.
******************************************************************************/
uint64_t tlkd_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)
{
cpu_context_t *ns_cpu_context;
gp_regs_t *gp_regs;
uint32_t ns;
uint64_t par;
/* Passing a NULL context is a critical programming error */
assert(handle);
/* These SMCs are only supported by a single CPU */
if (boot_cpu != plat_my_core_pos())
SMC_RET1(handle, SMC_UNK);
/* Determine which security state this SMC originated from */
ns = is_caller_non_secure(flags);
switch (smc_fid) {
/*
* This function ID is used by SP to indicate that it was
* preempted by a non-secure world IRQ.
*/
case TLK_PREEMPTED:
if (ns)
SMC_RET1(handle, SMC_UNK);
assert(handle == cm_get_context(SECURE));
cm_el1_sysregs_context_save(SECURE);
/* Get a reference to the non-secure context */
ns_cpu_context = cm_get_context(NON_SECURE);
assert(ns_cpu_context);
/*
* Restore non-secure state. There is no need to save the
* secure system register context since the SP was supposed
* to preserve it during S-EL1 interrupt handling.
*/
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
SMC_RET1(ns_cpu_context, x1);
/*
* This is a request from the non-secure context to:
*
* a. register shared memory with the SP for storing it's
* activity logs.
* b. register shared memory with the SP for passing args
* required for maintaining sessions with the Trusted
* Applications.
* c. open/close sessions
* d. issue commands to the Trusted Apps
* e. resume the preempted yielding SMC call.
*/
case TLK_REGISTER_LOGBUF:
case TLK_REGISTER_REQBUF:
case TLK_OPEN_TA_SESSION:
case TLK_CLOSE_TA_SESSION:
case TLK_TA_LAUNCH_OP:
case TLK_TA_SEND_EVENT:
case TLK_RESUME_FID:
if (!ns)
SMC_RET1(handle, SMC_UNK);
/*
* This is a fresh request from the non-secure client.
* The parameters are in x1 and x2. Figure out which
* registers need to be preserved, save the non-secure
* state and send the request to the secure payload.
*/
assert(handle == cm_get_context(NON_SECURE));
/*
* Check if we are already processing a yielding SMC
* call. Of all the supported fids, only the "resume"
* fid expects the flag to be set.
*/
if (smc_fid == TLK_RESUME_FID) {
if (!get_yield_smc_active_flag(tlk_ctx.state))
SMC_RET1(handle, SMC_UNK);
} else {
if (get_yield_smc_active_flag(tlk_ctx.state))
SMC_RET1(handle, SMC_UNK);
}
cm_el1_sysregs_context_save(NON_SECURE);
/*
* Verify if there is a valid context to use.
*/
assert(&tlk_ctx.cpu_ctx == cm_get_context(SECURE));
/*
* Mark the SP state as active.
*/
set_yield_smc_active_flag(tlk_ctx.state);
/*
* We are done stashing the non-secure context. Ask the
* secure payload to do the work now.
*/
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
/*
* TLK is a 32-bit Trusted OS and so expects the SMC
* arguments via r0-r7. TLK expects the monitor frame
* registers to be 64-bits long. Hence, we pass x0 in
* r0-r1, x1 in r2-r3, x3 in r4-r5 and x4 in r6-r7.
*
* As smc_fid is a uint32 value, r1 contains 0.
*/
gp_regs = get_gpregs_ctx(&tlk_ctx.cpu_ctx);
write_ctx_reg(gp_regs, CTX_GPREG_X4, (uint32_t)x2);
write_ctx_reg(gp_regs, CTX_GPREG_X5, (uint32_t)(x2 >> 32));
write_ctx_reg(gp_regs, CTX_GPREG_X6, (uint32_t)x3);
write_ctx_reg(gp_regs, CTX_GPREG_X7, (uint32_t)(x3 >> 32));
SMC_RET4(&tlk_ctx.cpu_ctx, smc_fid, 0, (uint32_t)x1,
(uint32_t)(x1 >> 32));
/*
* Translate NS/EL1-S virtual addresses.
*
* x1 = virtual address
* x3 = type (NS/S)
*
* Returns PA:lo in r0, PA:hi in r1.
*/
case TLK_VA_TRANSLATE:
/* Should be invoked only by secure world */
if (ns)
SMC_RET1(handle, SMC_UNK);
/* NS virtual addresses are 64-bit long */
if (x3 & TLK_TRANSLATE_NS_VADDR)
x1 = (uint32_t)x1 | (x2 << 32);
if (!x1)
SMC_RET1(handle, SMC_UNK);
/*
* TODO: Sanity check x1. This would require platform
* support.
*/
/* virtual address and type: ns/s */
par = tlkd_va_translate(x1, x3);
/* return physical address in r0-r1 */
SMC_RET4(handle, (uint32_t)par, (uint32_t)(par >> 32), 0, 0);
/*
* This is a request from the SP to mark completion of
* a yielding function ID.
*/
case TLK_REQUEST_DONE:
if (ns)
SMC_RET1(handle, SMC_UNK);
/*
* Mark the SP state as inactive.
*/
clr_yield_smc_active_flag(tlk_ctx.state);
/* Get a reference to the non-secure context */
ns_cpu_context = cm_get_context(NON_SECURE);
assert(ns_cpu_context);
/*
* This is a request completion SMC and we must switch to
* the non-secure world to pass the result.
*/
cm_el1_sysregs_context_save(SECURE);
/*
* We are done stashing the secure context. Switch to the
* non-secure context and return the result.
*/
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
SMC_RET1(ns_cpu_context, x1);
/*
* This function ID is used only by the SP to indicate it has
* finished initialising itself after a cold boot
*/
case TLK_ENTRY_DONE:
if (ns)
SMC_RET1(handle, SMC_UNK);
/*
* SP has been successfully initialized. Register power
* managemnt hooks with PSCI
*/
psci_register_spd_pm_hook(&tlkd_pm_ops);
/*
* TLK reports completion. The SPD must have initiated
* the original request through a synchronous entry
* into the SP. Jump back to the original C runtime
* context.
*/
tlkd_synchronous_sp_exit(&tlk_ctx, x1);
/*
* These function IDs are used only by TLK to indicate it has
* finished:
* 1. suspending itself after an earlier psci cpu_suspend
* request.
* 2. resuming itself after an earlier psci cpu_suspend
* request.
* 3. powering down after an earlier psci system_off/system_reset
* request.
*/
case TLK_SUSPEND_DONE:
case TLK_RESUME_DONE:
case TLK_SYSTEM_OFF_DONE:
if (ns)
SMC_RET1(handle, SMC_UNK);
/*
* TLK reports completion. TLKD must have initiated the
* original request through a synchronous entry into the SP.
* Jump back to the original C runtime context, and pass x1 as
* return value to the caller
*/
tlkd_synchronous_sp_exit(&tlk_ctx, x1);
/*
* Return the number of service function IDs implemented to
* provide service to non-secure
*/
case TOS_CALL_COUNT:
SMC_RET1(handle, TLK_NUM_FID);
/*
* Return TLK's UID to the caller
*/
case TOS_UID:
SMC_UUID_RET(handle, tlk_uuid);
/*
* Return the version of current implementation
*/
case TOS_CALL_VERSION:
SMC_RET2(handle, TLK_VERSION_MAJOR, TLK_VERSION_MINOR);
default:
break;
}
SMC_RET1(handle, SMC_UNK);
}
/* Define a SPD runtime service descriptor for fast SMC calls */
DECLARE_RT_SVC(
tlkd_tos_fast,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_FAST,
tlkd_setup,
tlkd_smc_handler
);
/* Define a SPD runtime service descriptor for yielding SMC calls */
DECLARE_RT_SVC(
tlkd_tos_std,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_YIELD,
NULL,
tlkd_smc_handler
);
/* Define a SPD runtime service descriptor for fast SMC calls */
DECLARE_RT_SVC(
tlkd_tap_fast,
OEN_TAP_START,
OEN_TAP_END,
SMC_TYPE_FAST,
NULL,
tlkd_smc_handler
);
/* Define a SPD runtime service descriptor for yielding SMC calls */
DECLARE_RT_SVC(
tlkd_tap_std,
OEN_TAP_START,
OEN_TAP_END,
SMC_TYPE_YIELD,
NULL,
tlkd_smc_handler
);