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Achin Gupta7aea9082014-02-01 07:51:28 +00001/*
Soby Mathewb0082d22015-04-09 13:40:55 +01002 * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
Achin Gupta7aea9082014-02-01 07:51:28 +00003 *
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
Achin Gupta27b895e2014-05-04 18:38:28 +010031#include <arch.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000032#include <arch_helpers.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010033#include <assert.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000034#include <bl_common.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010035#include <context.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000036#include <context_mgmt.h>
Achin Gupta191e86e2014-05-09 10:03:15 +010037#include <interrupt_mgmt.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010038#include <platform.h>
Dan Handleyed6ff952014-05-14 17:44:19 +010039#include <platform_def.h>
Yatharth Kochar6c0566c2015-10-02 17:56:48 +010040#include <smcc_helpers.h>
Andrew Thoelke4e126072014-06-04 21:10:52 +010041#include <string.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000042
Achin Gupta7aea9082014-02-01 07:51:28 +000043
44/*******************************************************************************
45 * Context management library initialisation routine. This library is used by
46 * runtime services to share pointers to 'cpu_context' structures for the secure
47 * and non-secure states. Management of the structures and their associated
48 * memory is not done by the context management library e.g. the PSCI service
49 * manages the cpu context used for entry from and exit to the non-secure state.
50 * The Secure payload dispatcher service manages the context(s) corresponding to
51 * the secure state. It also uses this library to get access to the non-secure
52 * state cpu context pointers.
53 * Lastly, this library provides the api to make SP_EL3 point to the cpu context
54 * which will used for programming an entry into a lower EL. The same context
55 * will used to save state upon exception entry from that EL.
56 ******************************************************************************/
Juan Castillo2d552402014-06-13 17:05:10 +010057void cm_init(void)
Achin Gupta7aea9082014-02-01 07:51:28 +000058{
59 /*
60 * The context management library has only global data to intialize, but
61 * that will be done when the BSS is zeroed out
62 */
63}
64
65/*******************************************************************************
Soby Mathewb0082d22015-04-09 13:40:55 +010066 * The following function initializes the cpu_context 'ctx' for
Andrew Thoelke4e126072014-06-04 21:10:52 +010067 * first use, and sets the initial entrypoint state as specified by the
68 * entry_point_info structure.
69 *
70 * The security state to initialize is determined by the SECURE attribute
71 * of the entry_point_info. The function returns a pointer to the initialized
72 * context and sets this as the next context to return to.
73 *
74 * The EE and ST attributes are used to configure the endianess and secure
Soby Mathewb0082d22015-04-09 13:40:55 +010075 * timer availability for the new execution context.
Andrew Thoelke4e126072014-06-04 21:10:52 +010076 *
77 * To prepare the register state for entry call cm_prepare_el3_exit() and
78 * el3_exit(). For Secure-EL1 cm_prepare_el3_exit() is equivalent to
79 * cm_e1_sysreg_context_restore().
80 ******************************************************************************/
Soby Mathewb0082d22015-04-09 13:40:55 +010081static void cm_init_context_common(cpu_context_t *ctx, const entry_point_info_t *ep)
Andrew Thoelke4e126072014-06-04 21:10:52 +010082{
Soby Mathewb0082d22015-04-09 13:40:55 +010083 unsigned int security_state;
Andrew Thoelke4e126072014-06-04 21:10:52 +010084 uint32_t scr_el3;
85 el3_state_t *state;
86 gp_regs_t *gp_regs;
87 unsigned long sctlr_elx;
88
Andrew Thoelke4e126072014-06-04 21:10:52 +010089 assert(ctx);
90
Soby Mathewb0082d22015-04-09 13:40:55 +010091 security_state = GET_SECURITY_STATE(ep->h.attr);
92
Andrew Thoelke4e126072014-06-04 21:10:52 +010093 /* Clear any residual register values from the context */
94 memset(ctx, 0, sizeof(*ctx));
95
96 /*
97 * Base the context SCR on the current value, adjust for entry point
98 * specific requirements and set trap bits from the IMF
99 * TODO: provide the base/global SCR bits using another mechanism?
100 */
101 scr_el3 = read_scr();
102 scr_el3 &= ~(SCR_NS_BIT | SCR_RW_BIT | SCR_FIQ_BIT | SCR_IRQ_BIT |
103 SCR_ST_BIT | SCR_HCE_BIT);
104
105 if (security_state != SECURE)
106 scr_el3 |= SCR_NS_BIT;
107
108 if (GET_RW(ep->spsr) == MODE_RW_64)
109 scr_el3 |= SCR_RW_BIT;
110
111 if (EP_GET_ST(ep->h.attr))
112 scr_el3 |= SCR_ST_BIT;
113
Gerald Lejeune632d6df2016-03-22 09:29:23 +0100114#ifndef HANDLE_EA_EL3_FIRST
115 /* Explicitly stop to trap aborts from lower exception levels. */
116 scr_el3 &= ~SCR_EA_BIT;
117#endif
118
Yatharth Kochar6c0566c2015-10-02 17:56:48 +0100119#if IMAGE_BL31
120 /*
121 * IRQ/FIQ bits only need setting if interrupt routing
122 * model has been set up for BL31.
123 */
Andrew Thoelke4e126072014-06-04 21:10:52 +0100124 scr_el3 |= get_scr_el3_from_routing_model(security_state);
Yatharth Kochar6c0566c2015-10-02 17:56:48 +0100125#endif
Andrew Thoelke4e126072014-06-04 21:10:52 +0100126
127 /*
128 * Set up SCTLR_ELx for the target exception level:
Soren Brinkmanna3b3c052016-04-18 10:46:19 -0700129 * EE bit is taken from the entrypoint attributes
Andrew Thoelke4e126072014-06-04 21:10:52 +0100130 * M, C and I bits must be zero (as required by PSCI specification)
131 *
132 * The target exception level is based on the spsr mode requested.
133 * If execution is requested to EL2 or hyp mode, HVC is enabled
134 * via SCR_EL3.HCE.
135 *
136 * Always compute the SCTLR_EL1 value and save in the cpu_context
137 * - the EL2 registers are set up by cm_preapre_ns_entry() as they
138 * are not part of the stored cpu_context
139 *
140 * TODO: In debug builds the spsr should be validated and checked
141 * against the CPU support, security state, endianess and pc
142 */
143 sctlr_elx = EP_GET_EE(ep->h.attr) ? SCTLR_EE_BIT : 0;
Jens Wiklanderc93c9df2014-09-04 10:23:27 +0200144 if (GET_RW(ep->spsr) == MODE_RW_64)
145 sctlr_elx |= SCTLR_EL1_RES1;
146 else
147 sctlr_elx |= SCTLR_AARCH32_EL1_RES1;
Andrew Thoelke4e126072014-06-04 21:10:52 +0100148 write_ctx_reg(get_sysregs_ctx(ctx), CTX_SCTLR_EL1, sctlr_elx);
149
150 if ((GET_RW(ep->spsr) == MODE_RW_64
151 && GET_EL(ep->spsr) == MODE_EL2)
152 || (GET_RW(ep->spsr) != MODE_RW_64
153 && GET_M32(ep->spsr) == MODE32_hyp)) {
154 scr_el3 |= SCR_HCE_BIT;
155 }
156
157 /* Populate EL3 state so that we've the right context before doing ERET */
158 state = get_el3state_ctx(ctx);
159 write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
160 write_ctx_reg(state, CTX_ELR_EL3, ep->pc);
161 write_ctx_reg(state, CTX_SPSR_EL3, ep->spsr);
162
163 /*
164 * Store the X0-X7 value from the entrypoint into the context
165 * Use memcpy as we are in control of the layout of the structures
166 */
167 gp_regs = get_gpregs_ctx(ctx);
168 memcpy(gp_regs, (void *)&ep->args, sizeof(aapcs64_params_t));
169}
170
171/*******************************************************************************
Soby Mathewb0082d22015-04-09 13:40:55 +0100172 * The following function initializes the cpu_context for a CPU specified by
173 * its `cpu_idx` for first use, and sets the initial entrypoint state as
174 * specified by the entry_point_info structure.
175 ******************************************************************************/
176void cm_init_context_by_index(unsigned int cpu_idx,
177 const entry_point_info_t *ep)
178{
179 cpu_context_t *ctx;
180 ctx = cm_get_context_by_index(cpu_idx, GET_SECURITY_STATE(ep->h.attr));
181 cm_init_context_common(ctx, ep);
182}
183
184/*******************************************************************************
185 * The following function initializes the cpu_context for the current CPU
186 * for first use, and sets the initial entrypoint state as specified by the
187 * entry_point_info structure.
188 ******************************************************************************/
189void cm_init_my_context(const entry_point_info_t *ep)
190{
191 cpu_context_t *ctx;
192 ctx = cm_get_context(GET_SECURITY_STATE(ep->h.attr));
193 cm_init_context_common(ctx, ep);
194}
195
196/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +0100197 * Prepare the CPU system registers for first entry into secure or normal world
198 *
199 * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
200 * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
201 * EL2 then EL2 is disabled by configuring all necessary EL2 registers.
202 * For all entries, the EL1 registers are initialized from the cpu_context
203 ******************************************************************************/
204void cm_prepare_el3_exit(uint32_t security_state)
205{
206 uint32_t sctlr_elx, scr_el3, cptr_el2;
207 cpu_context_t *ctx = cm_get_context(security_state);
208
209 assert(ctx);
210
211 if (security_state == NON_SECURE) {
212 scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
213 if (scr_el3 & SCR_HCE_BIT) {
214 /* Use SCTLR_EL1.EE value to initialise sctlr_el2 */
215 sctlr_elx = read_ctx_reg(get_sysregs_ctx(ctx),
216 CTX_SCTLR_EL1);
217 sctlr_elx &= ~SCTLR_EE_BIT;
218 sctlr_elx |= SCTLR_EL2_RES1;
219 write_sctlr_el2(sctlr_elx);
220 } else if (read_id_aa64pfr0_el1() &
221 (ID_AA64PFR0_ELX_MASK << ID_AA64PFR0_EL2_SHIFT)) {
222 /* EL2 present but unused, need to disable safely */
223
224 /* HCR_EL2 = 0, except RW bit set to match SCR_EL3 */
225 write_hcr_el2((scr_el3 & SCR_RW_BIT) ? HCR_RW_BIT : 0);
226
227 /* SCTLR_EL2 : can be ignored when bypassing */
228
229 /* CPTR_EL2 : disable all traps TCPAC, TTA, TFP */
230 cptr_el2 = read_cptr_el2();
231 cptr_el2 &= ~(TCPAC_BIT | TTA_BIT | TFP_BIT);
232 write_cptr_el2(cptr_el2);
233
234 /* Enable EL1 access to timer */
235 write_cnthctl_el2(EL1PCEN_BIT | EL1PCTEN_BIT);
236
Soby Mathewfeddfcf2014-08-29 14:41:58 +0100237 /* Reset CNTVOFF_EL2 */
238 write_cntvoff_el2(0);
239
Andrew Thoelke4e126072014-06-04 21:10:52 +0100240 /* Set VPIDR, VMPIDR to match MIDR, MPIDR */
241 write_vpidr_el2(read_midr_el1());
242 write_vmpidr_el2(read_mpidr_el1());
Sandrine Bailleux8b0eafe2015-11-25 17:00:44 +0000243
244 /*
245 * Reset VTTBR_EL2.
246 * Needed because cache maintenance operations depend on
247 * the VMID even when non-secure EL1&0 stage 2 address
248 * translation are disabled.
249 */
250 write_vttbr_el2(0);
Andrew Thoelke4e126072014-06-04 21:10:52 +0100251 }
252 }
253
254 el1_sysregs_context_restore(get_sysregs_ctx(ctx));
255
256 cm_set_next_context(ctx);
257}
258
259/*******************************************************************************
Soby Mathew2ed46e92014-07-04 16:02:26 +0100260 * The next four functions are used by runtime services to save and restore
261 * EL1 context on the 'cpu_context' structure for the specified security
Achin Gupta7aea9082014-02-01 07:51:28 +0000262 * state.
263 ******************************************************************************/
Achin Gupta7aea9082014-02-01 07:51:28 +0000264void cm_el1_sysregs_context_save(uint32_t security_state)
265{
Dan Handleye2712bc2014-04-10 15:37:22 +0100266 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000267
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100268 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000269 assert(ctx);
270
271 el1_sysregs_context_save(get_sysregs_ctx(ctx));
272}
273
274void cm_el1_sysregs_context_restore(uint32_t security_state)
275{
Dan Handleye2712bc2014-04-10 15:37:22 +0100276 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000277
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100278 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000279 assert(ctx);
280
281 el1_sysregs_context_restore(get_sysregs_ctx(ctx));
282}
283
284/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +0100285 * This function populates ELR_EL3 member of 'cpu_context' pertaining to the
286 * given security state with the given entrypoint
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000287 ******************************************************************************/
Andrew Thoelke4e126072014-06-04 21:10:52 +0100288void cm_set_elr_el3(uint32_t security_state, uint64_t entrypoint)
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000289{
Dan Handleye2712bc2014-04-10 15:37:22 +0100290 cpu_context_t *ctx;
291 el3_state_t *state;
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000292
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100293 ctx = cm_get_context(security_state);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000294 assert(ctx);
295
Andrew Thoelke4e126072014-06-04 21:10:52 +0100296 /* Populate EL3 state so that ERET jumps to the correct entry */
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000297 state = get_el3state_ctx(ctx);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000298 write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000299}
300
301/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +0100302 * This function populates ELR_EL3 and SPSR_EL3 members of 'cpu_context'
303 * pertaining to the given security state
Achin Gupta607084e2014-02-09 18:24:19 +0000304 ******************************************************************************/
Andrew Thoelke4e126072014-06-04 21:10:52 +0100305void cm_set_elr_spsr_el3(uint32_t security_state,
306 uint64_t entrypoint, uint32_t spsr)
Achin Gupta607084e2014-02-09 18:24:19 +0000307{
Dan Handleye2712bc2014-04-10 15:37:22 +0100308 cpu_context_t *ctx;
309 el3_state_t *state;
Achin Gupta607084e2014-02-09 18:24:19 +0000310
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100311 ctx = cm_get_context(security_state);
Achin Gupta607084e2014-02-09 18:24:19 +0000312 assert(ctx);
313
314 /* Populate EL3 state so that ERET jumps to the correct entry */
315 state = get_el3state_ctx(ctx);
316 write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
Andrew Thoelke4e126072014-06-04 21:10:52 +0100317 write_ctx_reg(state, CTX_SPSR_EL3, spsr);
Achin Gupta607084e2014-02-09 18:24:19 +0000318}
319
320/*******************************************************************************
Achin Gupta27b895e2014-05-04 18:38:28 +0100321 * This function updates a single bit in the SCR_EL3 member of the 'cpu_context'
322 * pertaining to the given security state using the value and bit position
323 * specified in the parameters. It preserves all other bits.
324 ******************************************************************************/
325void cm_write_scr_el3_bit(uint32_t security_state,
326 uint32_t bit_pos,
327 uint32_t value)
328{
329 cpu_context_t *ctx;
330 el3_state_t *state;
331 uint32_t scr_el3;
332
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100333 ctx = cm_get_context(security_state);
Achin Gupta27b895e2014-05-04 18:38:28 +0100334 assert(ctx);
335
336 /* Ensure that the bit position is a valid one */
337 assert((1 << bit_pos) & SCR_VALID_BIT_MASK);
338
339 /* Ensure that the 'value' is only a bit wide */
340 assert(value <= 1);
341
342 /*
343 * Get the SCR_EL3 value from the cpu context, clear the desired bit
344 * and set it to its new value.
345 */
346 state = get_el3state_ctx(ctx);
347 scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
348 scr_el3 &= ~(1 << bit_pos);
349 scr_el3 |= value << bit_pos;
350 write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
351}
352
353/*******************************************************************************
354 * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the
355 * given security state.
356 ******************************************************************************/
357uint32_t cm_get_scr_el3(uint32_t security_state)
358{
359 cpu_context_t *ctx;
360 el3_state_t *state;
361
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100362 ctx = cm_get_context(security_state);
Achin Gupta27b895e2014-05-04 18:38:28 +0100363 assert(ctx);
364
365 /* Populate EL3 state so that ERET jumps to the correct entry */
366 state = get_el3state_ctx(ctx);
367 return read_ctx_reg(state, CTX_SCR_EL3);
368}
369
370/*******************************************************************************
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000371 * This function is used to program the context that's used for exception
372 * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
373 * the required security state
Achin Gupta7aea9082014-02-01 07:51:28 +0000374 ******************************************************************************/
375void cm_set_next_eret_context(uint32_t security_state)
376{
Dan Handleye2712bc2014-04-10 15:37:22 +0100377 cpu_context_t *ctx;
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000378
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100379 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000380 assert(ctx);
381
Andrew Thoelke4e126072014-06-04 21:10:52 +0100382 cm_set_next_context(ctx);
Achin Gupta7aea9082014-02-01 07:51:28 +0000383}