1/*
2 * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#include <arch_helpers.h>
8#include <assert.h>
9#include <bl_common.h>
10#include <context_mgmt.h>
11#include <string.h>
12#include "tlkd_private.h"
13
14#define AT_MASK		3
15
16/*******************************************************************************
17 * This function helps the SP to translate NS/S virtual addresses.
18 ******************************************************************************/
19uint64_t tlkd_va_translate(uintptr_t va, int type)
20{
21	uint64_t pa;
22
23	if (type & TLK_TRANSLATE_NS_VADDR) {
24
25		/* save secure context */
26		cm_el1_sysregs_context_save(SECURE);
27
28		/* restore non-secure context */
29		cm_el1_sysregs_context_restore(NON_SECURE);
30
31		/* switch NS bit to start using 64-bit, non-secure mappings */
32		write_scr(cm_get_scr_el3(NON_SECURE));
33		isb();
34	}
35
36	int at = type & AT_MASK;
37	switch (at) {
38	case 0:
39		ats12e1r(va);
40		break;
41	case 1:
42		ats12e1w(va);
43		break;
44	case 2:
45		ats12e0r(va);
46		break;
47	case 3:
48		ats12e0w(va);
49		break;
50	default:
51		assert(0);
52	}
53
54	/* get the (NS/S) physical address */
55	isb();
56	pa = read_par_el1();
57
58	/* Restore secure state */
59	if (type & TLK_TRANSLATE_NS_VADDR) {
60
61		/* restore secure context */
62		cm_el1_sysregs_context_restore(SECURE);
63
64		/* switch NS bit to start using 32-bit, secure mappings */
65		write_scr(cm_get_scr_el3(SECURE));
66		isb();
67	}
68
69	return pa;
70}
71
72/*******************************************************************************
73 * Given a secure payload entrypoint, register width, cpu id & pointer to a
74 * context data structure, this function will create a secure context ready for
75 * programming an entry into the secure payload.
76 ******************************************************************************/
77void tlkd_init_tlk_ep_state(struct entry_point_info *tlk_entry_point,
78			    uint32_t rw,
79			    uint64_t pc,
80			    tlk_context_t *tlk_ctx)
81{
82	uint32_t ep_attr, spsr;
83
84	/* Passing a NULL context is a critical programming error */
85	assert(tlk_ctx);
86	assert(tlk_entry_point);
87	assert(pc);
88
89	/* Associate this context with the cpu specified */
90	tlk_ctx->mpidr = read_mpidr_el1();
91	clr_yield_smc_active_flag(tlk_ctx->state);
92	cm_set_context(&tlk_ctx->cpu_ctx, SECURE);
93
94	if (rw == SP_AARCH64)
95		spsr = SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS);
96	else
97		spsr = SPSR_MODE32(MODE32_svc,
98				   SPSR_T_ARM,
99				   read_sctlr_el3() & SCTLR_EE_BIT,
100				   DISABLE_ALL_EXCEPTIONS);
101
102	/* initialise an entrypoint to set up the CPU context */
103	ep_attr = SECURE | EP_ST_ENABLE;
104	if (read_sctlr_el3() & SCTLR_EE_BIT)
105		ep_attr |= EP_EE_BIG;
106	SET_PARAM_HEAD(tlk_entry_point, PARAM_EP, VERSION_1, ep_attr);
107
108	tlk_entry_point->pc = pc;
109	tlk_entry_point->spsr = spsr;
110}
111
112/*******************************************************************************
113 * This function takes a TLK context pointer and:
114 * 1. Applies the S-EL1 system register context from tlk_ctx->cpu_ctx.
115 * 2. Saves the current C runtime state (callee saved registers) on the stack
116 *    frame and saves a reference to this state.
117 * 3. Calls el3_exit() so that the EL3 system and general purpose registers
118 *    from the tlk_ctx->cpu_ctx are used to enter the secure payload image.
119 ******************************************************************************/
120uint64_t tlkd_synchronous_sp_entry(tlk_context_t *tlk_ctx)
121{
122	uint64_t rc;
123
124	/* Passing a NULL context is a critical programming error */
125	assert(tlk_ctx);
126	assert(tlk_ctx->c_rt_ctx == 0);
127
128	/* Apply the Secure EL1 system register context and switch to it */
129	assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx);
130	cm_el1_sysregs_context_restore(SECURE);
131	cm_set_next_eret_context(SECURE);
132
133	rc = tlkd_enter_sp(&tlk_ctx->c_rt_ctx);
134#if DEBUG
135	tlk_ctx->c_rt_ctx = 0;
136#endif
137
138	return rc;
139}
140
141/*******************************************************************************
142 * This function takes a TLK context pointer and:
143 * 1. Saves the S-EL1 system register context to tlk_ctx->cpu_ctx.
144 * 2. Restores the current C runtime state (callee saved registers) from the
145 *    stack frame using reference to this state saved in tlkd_enter_sp().
146 * 3. It does not need to save any general purpose or EL3 system register state
147 *    as the generic smc entry routine should have saved those.
148 ******************************************************************************/
149void tlkd_synchronous_sp_exit(tlk_context_t *tlk_ctx, uint64_t ret)
150{
151	/* Passing a NULL context is a critical programming error */
152	assert(tlk_ctx);
153
154	/* Save the Secure EL1 system register context */
155	assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx);
156	cm_el1_sysregs_context_save(SECURE);
157
158	assert(tlk_ctx->c_rt_ctx != 0);
159	tlkd_exit_sp(tlk_ctx->c_rt_ctx, ret);
160
161	/* Should never reach here */
162	assert(0);
163}
164