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      1 /*
      2  * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are met:
      6  *
      7  * Redistributions of source code must retain the above copyright notice, this
      8  * list of conditions and the following disclaimer.
      9  *
     10  * Redistributions in binary form must reproduce the above copyright notice,
     11  * this list of conditions and the following disclaimer in the documentation
     12  * and/or other materials provided with the distribution.
     13  *
     14  * Neither the name of ARM nor the names of its contributors may be used
     15  * to endorse or promote products derived from this software without specific
     16  * prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
     22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     28  * POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <arch_helpers.h>
     32 #include <assert.h>
     33 #include <bl_common.h>
     34 #include <context_mgmt.h>
     35 #include <string.h>
     36 #include "opteed_private.h"
     37 
     38 /*******************************************************************************
     39  * Given a OPTEE entrypoint info pointer, entry point PC, register width,
     40  * cpu id & pointer to a context data structure, this function will
     41  * initialize OPTEE context and entry point info for OPTEE.
     42  ******************************************************************************/
     43 void opteed_init_optee_ep_state(struct entry_point_info *optee_entry_point,
     44 				uint32_t rw, uint64_t pc,
     45 				uint64_t paged_part, uint64_t mem_limit,
     46 				optee_context_t *optee_ctx)
     47 {
     48 	uint32_t ep_attr;
     49 
     50 	/* Passing a NULL context is a critical programming error */
     51 	assert(optee_ctx);
     52 	assert(optee_entry_point);
     53 	assert(pc);
     54 
     55 	/* Associate this context with the cpu specified */
     56 	optee_ctx->mpidr = read_mpidr_el1();
     57 	optee_ctx->state = 0;
     58 	set_optee_pstate(optee_ctx->state, OPTEE_PSTATE_OFF);
     59 
     60 	cm_set_context(&optee_ctx->cpu_ctx, SECURE);
     61 
     62 	/* initialise an entrypoint to set up the CPU context */
     63 	ep_attr = SECURE | EP_ST_ENABLE;
     64 	if (read_sctlr_el3() & SCTLR_EE_BIT)
     65 		ep_attr |= EP_EE_BIG;
     66 	SET_PARAM_HEAD(optee_entry_point, PARAM_EP, VERSION_1, ep_attr);
     67 	optee_entry_point->pc = pc;
     68 	if (rw == OPTEE_AARCH64)
     69 		optee_entry_point->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
     70 						  DISABLE_ALL_EXCEPTIONS);
     71 	else
     72 		optee_entry_point->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM,
     73 						      SPSR_E_LITTLE,
     74 						      DAIF_FIQ_BIT |
     75 							DAIF_IRQ_BIT |
     76 							DAIF_ABT_BIT);
     77 	memset(&optee_entry_point->args, 0, sizeof(optee_entry_point->args));
     78 	optee_entry_point->args.arg0 = paged_part;
     79 	optee_entry_point->args.arg1 = mem_limit;
     80 }
     81 
     82 /*******************************************************************************
     83  * This function takes an OPTEE context pointer and:
     84  * 1. Applies the S-EL1 system register context from optee_ctx->cpu_ctx.
     85  * 2. Saves the current C runtime state (callee saved registers) on the stack
     86  *    frame and saves a reference to this state.
     87  * 3. Calls el3_exit() so that the EL3 system and general purpose registers
     88  *    from the optee_ctx->cpu_ctx are used to enter the OPTEE image.
     89  ******************************************************************************/
     90 uint64_t opteed_synchronous_sp_entry(optee_context_t *optee_ctx)
     91 {
     92 	uint64_t rc;
     93 
     94 	assert(optee_ctx != NULL);
     95 	assert(optee_ctx->c_rt_ctx == 0);
     96 
     97 	/* Apply the Secure EL1 system register context and switch to it */
     98 	assert(cm_get_context(SECURE) == &optee_ctx->cpu_ctx);
     99 	cm_el1_sysregs_context_restore(SECURE);
    100 	cm_set_next_eret_context(SECURE);
    101 
    102 	rc = opteed_enter_sp(&optee_ctx->c_rt_ctx);
    103 #if DEBUG
    104 	optee_ctx->c_rt_ctx = 0;
    105 #endif
    106 
    107 	return rc;
    108 }
    109 
    110 
    111 /*******************************************************************************
    112  * This function takes an OPTEE context pointer and:
    113  * 1. Saves the S-EL1 system register context tp optee_ctx->cpu_ctx.
    114  * 2. Restores the current C runtime state (callee saved registers) from the
    115  *    stack frame using the reference to this state saved in opteed_enter_sp().
    116  * 3. It does not need to save any general purpose or EL3 system register state
    117  *    as the generic smc entry routine should have saved those.
    118  ******************************************************************************/
    119 void opteed_synchronous_sp_exit(optee_context_t *optee_ctx, uint64_t ret)
    120 {
    121 	assert(optee_ctx != NULL);
    122 	/* Save the Secure EL1 system register context */
    123 	assert(cm_get_context(SECURE) == &optee_ctx->cpu_ctx);
    124 	cm_el1_sysregs_context_save(SECURE);
    125 
    126 	assert(optee_ctx->c_rt_ctx != 0);
    127 	opteed_exit_sp(optee_ctx->c_rt_ctx, ret);
    128 
    129 	/* Should never reach here */
    130 	assert(0);
    131 }
    132