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Achin Gupta7aea9082014-02-01 07:51:28 +00001/*
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
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>
Soby Mathew5e5c2072014-04-07 15:28:55 +010035#include <bl31.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010036#include <context.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000037#include <context_mgmt.h>
Andrew Thoelkec02dbd62014-06-02 10:00:25 +010038#include <cpu_data.h>
Achin Gupta191e86e2014-05-09 10:03:15 +010039#include <interrupt_mgmt.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010040#include <platform.h>
Dan Handleyed6ff952014-05-14 17:44:19 +010041#include <platform_def.h>
Dan Handley2bd4ef22014-04-09 13:14:54 +010042#include <runtime_svc.h>
Andrew Thoelke4e126072014-06-04 21:10:52 +010043#include <string.h>
Achin Gupta7aea9082014-02-01 07:51:28 +000044
Achin Gupta7aea9082014-02-01 07:51:28 +000045
46/*******************************************************************************
47 * Context management library initialisation routine. This library is used by
48 * runtime services to share pointers to 'cpu_context' structures for the secure
49 * and non-secure states. Management of the structures and their associated
50 * memory is not done by the context management library e.g. the PSCI service
51 * manages the cpu context used for entry from and exit to the non-secure state.
52 * The Secure payload dispatcher service manages the context(s) corresponding to
53 * the secure state. It also uses this library to get access to the non-secure
54 * state cpu context pointers.
55 * Lastly, this library provides the api to make SP_EL3 point to the cpu context
56 * which will used for programming an entry into a lower EL. The same context
57 * will used to save state upon exception entry from that EL.
58 ******************************************************************************/
Juan Castillo2d552402014-06-13 17:05:10 +010059void cm_init(void)
Achin Gupta7aea9082014-02-01 07:51:28 +000060{
61 /*
62 * The context management library has only global data to intialize, but
63 * that will be done when the BSS is zeroed out
64 */
65}
66
67/*******************************************************************************
68 * This function returns a pointer to the most recent 'cpu_context' structure
Andrew Thoelkea2f65532014-05-14 17:09:32 +010069 * for the CPU identified by MPIDR that was set as the context for the specified
70 * security state. NULL is returned if no such structure has been specified.
Achin Gupta7aea9082014-02-01 07:51:28 +000071 ******************************************************************************/
Andrew Thoelkea2f65532014-05-14 17:09:32 +010072void *cm_get_context_by_mpidr(uint64_t mpidr, uint32_t security_state)
Achin Gupta7aea9082014-02-01 07:51:28 +000073{
Andrew Thoelkea2f65532014-05-14 17:09:32 +010074 assert(security_state <= NON_SECURE);
75
Andrew Thoelkec02dbd62014-06-02 10:00:25 +010076 return get_cpu_data_by_mpidr(mpidr, cpu_context[security_state]);
Andrew Thoelkea2f65532014-05-14 17:09:32 +010077}
78
79/*******************************************************************************
Achin Gupta7aea9082014-02-01 07:51:28 +000080 * This function sets the pointer to the current 'cpu_context' structure for the
Andrew Thoelkea2f65532014-05-14 17:09:32 +010081 * specified security state for the CPU identified by MPIDR
Achin Gupta7aea9082014-02-01 07:51:28 +000082 ******************************************************************************/
Andrew Thoelkea2f65532014-05-14 17:09:32 +010083void cm_set_context_by_mpidr(uint64_t mpidr, void *context, uint32_t security_state)
Achin Gupta7aea9082014-02-01 07:51:28 +000084{
Achin Gupta7aea9082014-02-01 07:51:28 +000085 assert(security_state <= NON_SECURE);
86
Andrew Thoelkec02dbd62014-06-02 10:00:25 +010087 set_cpu_data_by_mpidr(mpidr, cpu_context[security_state], context);
Andrew Thoelkea2f65532014-05-14 17:09:32 +010088}
89
90/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +010091 * This function is used to program the context that's used for exception
92 * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
93 * the required security state
94 ******************************************************************************/
95static inline void cm_set_next_context(void *context)
96{
97#if DEBUG
98 uint64_t sp_mode;
99
100 /*
101 * Check that this function is called with SP_EL0 as the stack
102 * pointer
103 */
104 __asm__ volatile("mrs %0, SPSel\n"
105 : "=r" (sp_mode));
106
107 assert(sp_mode == MODE_SP_EL0);
108#endif
109
110 __asm__ volatile("msr spsel, #1\n"
111 "mov sp, %0\n"
112 "msr spsel, #0\n"
113 : : "r" (context));
114}
115
116/*******************************************************************************
117 * The following function initializes a cpu_context for the current CPU for
118 * first use, and sets the initial entrypoint state as specified by the
119 * entry_point_info structure.
120 *
121 * The security state to initialize is determined by the SECURE attribute
122 * of the entry_point_info. The function returns a pointer to the initialized
123 * context and sets this as the next context to return to.
124 *
125 * The EE and ST attributes are used to configure the endianess and secure
126 * timer availability for the new excution context.
127 *
128 * To prepare the register state for entry call cm_prepare_el3_exit() and
129 * el3_exit(). For Secure-EL1 cm_prepare_el3_exit() is equivalent to
130 * cm_e1_sysreg_context_restore().
131 ******************************************************************************/
132void cm_init_context(uint64_t mpidr, const entry_point_info_t *ep)
133{
134 uint32_t security_state;
135 cpu_context_t *ctx;
136 uint32_t scr_el3;
137 el3_state_t *state;
138 gp_regs_t *gp_regs;
139 unsigned long sctlr_elx;
140
141 security_state = GET_SECURITY_STATE(ep->h.attr);
142 ctx = cm_get_context_by_mpidr(mpidr, security_state);
143 assert(ctx);
144
145 /* Clear any residual register values from the context */
146 memset(ctx, 0, sizeof(*ctx));
147
148 /*
149 * Base the context SCR on the current value, adjust for entry point
150 * specific requirements and set trap bits from the IMF
151 * TODO: provide the base/global SCR bits using another mechanism?
152 */
153 scr_el3 = read_scr();
154 scr_el3 &= ~(SCR_NS_BIT | SCR_RW_BIT | SCR_FIQ_BIT | SCR_IRQ_BIT |
155 SCR_ST_BIT | SCR_HCE_BIT);
156
157 if (security_state != SECURE)
158 scr_el3 |= SCR_NS_BIT;
159
160 if (GET_RW(ep->spsr) == MODE_RW_64)
161 scr_el3 |= SCR_RW_BIT;
162
163 if (EP_GET_ST(ep->h.attr))
164 scr_el3 |= SCR_ST_BIT;
165
166 scr_el3 |= get_scr_el3_from_routing_model(security_state);
167
168 /*
169 * Set up SCTLR_ELx for the target exception level:
170 * EE bit is taken from the entrpoint attributes
171 * M, C and I bits must be zero (as required by PSCI specification)
172 *
173 * The target exception level is based on the spsr mode requested.
174 * If execution is requested to EL2 or hyp mode, HVC is enabled
175 * via SCR_EL3.HCE.
176 *
177 * Always compute the SCTLR_EL1 value and save in the cpu_context
178 * - the EL2 registers are set up by cm_preapre_ns_entry() as they
179 * are not part of the stored cpu_context
180 *
181 * TODO: In debug builds the spsr should be validated and checked
182 * against the CPU support, security state, endianess and pc
183 */
184 sctlr_elx = EP_GET_EE(ep->h.attr) ? SCTLR_EE_BIT : 0;
185 sctlr_elx |= SCTLR_EL1_RES1;
186 write_ctx_reg(get_sysregs_ctx(ctx), CTX_SCTLR_EL1, sctlr_elx);
187
188 if ((GET_RW(ep->spsr) == MODE_RW_64
189 && GET_EL(ep->spsr) == MODE_EL2)
190 || (GET_RW(ep->spsr) != MODE_RW_64
191 && GET_M32(ep->spsr) == MODE32_hyp)) {
192 scr_el3 |= SCR_HCE_BIT;
193 }
194
195 /* Populate EL3 state so that we've the right context before doing ERET */
196 state = get_el3state_ctx(ctx);
197 write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
198 write_ctx_reg(state, CTX_ELR_EL3, ep->pc);
199 write_ctx_reg(state, CTX_SPSR_EL3, ep->spsr);
200
201 /*
202 * Store the X0-X7 value from the entrypoint into the context
203 * Use memcpy as we are in control of the layout of the structures
204 */
205 gp_regs = get_gpregs_ctx(ctx);
206 memcpy(gp_regs, (void *)&ep->args, sizeof(aapcs64_params_t));
207}
208
209/*******************************************************************************
210 * Prepare the CPU system registers for first entry into secure or normal world
211 *
212 * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
213 * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
214 * EL2 then EL2 is disabled by configuring all necessary EL2 registers.
215 * For all entries, the EL1 registers are initialized from the cpu_context
216 ******************************************************************************/
217void cm_prepare_el3_exit(uint32_t security_state)
218{
219 uint32_t sctlr_elx, scr_el3, cptr_el2;
220 cpu_context_t *ctx = cm_get_context(security_state);
221
222 assert(ctx);
223
224 if (security_state == NON_SECURE) {
225 scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
226 if (scr_el3 & SCR_HCE_BIT) {
227 /* Use SCTLR_EL1.EE value to initialise sctlr_el2 */
228 sctlr_elx = read_ctx_reg(get_sysregs_ctx(ctx),
229 CTX_SCTLR_EL1);
230 sctlr_elx &= ~SCTLR_EE_BIT;
231 sctlr_elx |= SCTLR_EL2_RES1;
232 write_sctlr_el2(sctlr_elx);
233 } else if (read_id_aa64pfr0_el1() &
234 (ID_AA64PFR0_ELX_MASK << ID_AA64PFR0_EL2_SHIFT)) {
235 /* EL2 present but unused, need to disable safely */
236
237 /* HCR_EL2 = 0, except RW bit set to match SCR_EL3 */
238 write_hcr_el2((scr_el3 & SCR_RW_BIT) ? HCR_RW_BIT : 0);
239
240 /* SCTLR_EL2 : can be ignored when bypassing */
241
242 /* CPTR_EL2 : disable all traps TCPAC, TTA, TFP */
243 cptr_el2 = read_cptr_el2();
244 cptr_el2 &= ~(TCPAC_BIT | TTA_BIT | TFP_BIT);
245 write_cptr_el2(cptr_el2);
246
247 /* Enable EL1 access to timer */
248 write_cnthctl_el2(EL1PCEN_BIT | EL1PCTEN_BIT);
249
250 /* Set VPIDR, VMPIDR to match MIDR, MPIDR */
251 write_vpidr_el2(read_midr_el1());
252 write_vmpidr_el2(read_mpidr_el1());
253 }
254 }
255
256 el1_sysregs_context_restore(get_sysregs_ctx(ctx));
257
258 cm_set_next_context(ctx);
259}
260
261/*******************************************************************************
Achin Gupta7aea9082014-02-01 07:51:28 +0000262 * The next four functions are used by runtime services to save and restore EL3
263 * and EL1 contexts on the 'cpu_context' structure for the specified security
264 * state.
265 ******************************************************************************/
266void cm_el3_sysregs_context_save(uint32_t security_state)
267{
Dan Handleye2712bc2014-04-10 15:37:22 +0100268 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000269
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100270 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000271 assert(ctx);
272
273 el3_sysregs_context_save(get_el3state_ctx(ctx));
274}
275
276void cm_el3_sysregs_context_restore(uint32_t security_state)
277{
Dan Handleye2712bc2014-04-10 15:37:22 +0100278 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000279
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100280 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000281 assert(ctx);
282
283 el3_sysregs_context_restore(get_el3state_ctx(ctx));
284}
285
286void cm_el1_sysregs_context_save(uint32_t security_state)
287{
Dan Handleye2712bc2014-04-10 15:37:22 +0100288 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000289
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100290 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000291 assert(ctx);
292
293 el1_sysregs_context_save(get_sysregs_ctx(ctx));
294}
295
296void cm_el1_sysregs_context_restore(uint32_t security_state)
297{
Dan Handleye2712bc2014-04-10 15:37:22 +0100298 cpu_context_t *ctx;
Achin Gupta7aea9082014-02-01 07:51:28 +0000299
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100300 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000301 assert(ctx);
302
303 el1_sysregs_context_restore(get_sysregs_ctx(ctx));
304}
305
306/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +0100307 * This function populates ELR_EL3 member of 'cpu_context' pertaining to the
308 * given security state with the given entrypoint
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000309 ******************************************************************************/
Andrew Thoelke4e126072014-06-04 21:10:52 +0100310void cm_set_elr_el3(uint32_t security_state, uint64_t entrypoint)
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000311{
Dan Handleye2712bc2014-04-10 15:37:22 +0100312 cpu_context_t *ctx;
313 el3_state_t *state;
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000314
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100315 ctx = cm_get_context(security_state);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000316 assert(ctx);
317
Andrew Thoelke4e126072014-06-04 21:10:52 +0100318 /* Populate EL3 state so that ERET jumps to the correct entry */
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000319 state = get_el3state_ctx(ctx);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000320 write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000321}
322
323/*******************************************************************************
Andrew Thoelke4e126072014-06-04 21:10:52 +0100324 * This function populates ELR_EL3 and SPSR_EL3 members of 'cpu_context'
325 * pertaining to the given security state
Achin Gupta607084e2014-02-09 18:24:19 +0000326 ******************************************************************************/
Andrew Thoelke4e126072014-06-04 21:10:52 +0100327void cm_set_elr_spsr_el3(uint32_t security_state,
328 uint64_t entrypoint, uint32_t spsr)
Achin Gupta607084e2014-02-09 18:24:19 +0000329{
Dan Handleye2712bc2014-04-10 15:37:22 +0100330 cpu_context_t *ctx;
331 el3_state_t *state;
Achin Gupta607084e2014-02-09 18:24:19 +0000332
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100333 ctx = cm_get_context(security_state);
Achin Gupta607084e2014-02-09 18:24:19 +0000334 assert(ctx);
335
336 /* Populate EL3 state so that ERET jumps to the correct entry */
337 state = get_el3state_ctx(ctx);
338 write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
Andrew Thoelke4e126072014-06-04 21:10:52 +0100339 write_ctx_reg(state, CTX_SPSR_EL3, spsr);
Achin Gupta607084e2014-02-09 18:24:19 +0000340}
341
342/*******************************************************************************
Achin Gupta27b895e2014-05-04 18:38:28 +0100343 * This function updates a single bit in the SCR_EL3 member of the 'cpu_context'
344 * pertaining to the given security state using the value and bit position
345 * specified in the parameters. It preserves all other bits.
346 ******************************************************************************/
347void cm_write_scr_el3_bit(uint32_t security_state,
348 uint32_t bit_pos,
349 uint32_t value)
350{
351 cpu_context_t *ctx;
352 el3_state_t *state;
353 uint32_t scr_el3;
354
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100355 ctx = cm_get_context(security_state);
Achin Gupta27b895e2014-05-04 18:38:28 +0100356 assert(ctx);
357
358 /* Ensure that the bit position is a valid one */
359 assert((1 << bit_pos) & SCR_VALID_BIT_MASK);
360
361 /* Ensure that the 'value' is only a bit wide */
362 assert(value <= 1);
363
364 /*
365 * Get the SCR_EL3 value from the cpu context, clear the desired bit
366 * and set it to its new value.
367 */
368 state = get_el3state_ctx(ctx);
369 scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
370 scr_el3 &= ~(1 << bit_pos);
371 scr_el3 |= value << bit_pos;
372 write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
373}
374
375/*******************************************************************************
376 * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the
377 * given security state.
378 ******************************************************************************/
379uint32_t cm_get_scr_el3(uint32_t security_state)
380{
381 cpu_context_t *ctx;
382 el3_state_t *state;
383
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100384 ctx = cm_get_context(security_state);
Achin Gupta27b895e2014-05-04 18:38:28 +0100385 assert(ctx);
386
387 /* Populate EL3 state so that ERET jumps to the correct entry */
388 state = get_el3state_ctx(ctx);
389 return read_ctx_reg(state, CTX_SCR_EL3);
390}
391
392/*******************************************************************************
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000393 * This function is used to program the context that's used for exception
394 * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
395 * the required security state
Achin Gupta7aea9082014-02-01 07:51:28 +0000396 ******************************************************************************/
397void cm_set_next_eret_context(uint32_t security_state)
398{
Dan Handleye2712bc2014-04-10 15:37:22 +0100399 cpu_context_t *ctx;
Jeenu Viswambharancaa84932014-02-06 10:36:15 +0000400
Andrew Thoelkea2f65532014-05-14 17:09:32 +0100401 ctx = cm_get_context(security_state);
Achin Gupta7aea9082014-02-01 07:51:28 +0000402 assert(ctx);
403
Andrew Thoelke4e126072014-06-04 21:10:52 +0100404 cm_set_next_context(ctx);
Achin Gupta7aea9082014-02-01 07:51:28 +0000405}