1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
/*
* Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <context.h>
.global el1_sysregs_context_save
.global el1_sysregs_context_save_post_ops
.global el1_sysregs_context_restore
#if CTX_INCLUDE_FPREGS
.global fpregs_context_save
.global fpregs_context_restore
#endif
.global save_gp_registers
.global restore_gp_registers_eret
.global restore_gp_registers_callee_eret
.global el3_exit
/* -----------------------------------------------------
* The following function strictly follows the AArch64
* PCS to use x9-x17 (temporary caller-saved registers)
* to save EL1 system register context. It assumes that
* 'x0' is pointing to a 'el1_sys_regs' structure where
* the register context will be saved.
* -----------------------------------------------------
*/
func el1_sysregs_context_save
mrs x9, spsr_el1
mrs x10, elr_el1
stp x9, x10, [x0, #CTX_SPSR_EL1]
mrs x15, sctlr_el1
mrs x16, actlr_el1
stp x15, x16, [x0, #CTX_SCTLR_EL1]
mrs x17, cpacr_el1
mrs x9, csselr_el1
stp x17, x9, [x0, #CTX_CPACR_EL1]
mrs x10, sp_el1
mrs x11, esr_el1
stp x10, x11, [x0, #CTX_SP_EL1]
mrs x12, ttbr0_el1
mrs x13, ttbr1_el1
stp x12, x13, [x0, #CTX_TTBR0_EL1]
mrs x14, mair_el1
mrs x15, amair_el1
stp x14, x15, [x0, #CTX_MAIR_EL1]
mrs x16, tcr_el1
mrs x17, tpidr_el1
stp x16, x17, [x0, #CTX_TCR_EL1]
mrs x9, tpidr_el0
mrs x10, tpidrro_el0
stp x9, x10, [x0, #CTX_TPIDR_EL0]
mrs x13, par_el1
mrs x14, far_el1
stp x13, x14, [x0, #CTX_PAR_EL1]
mrs x15, afsr0_el1
mrs x16, afsr1_el1
stp x15, x16, [x0, #CTX_AFSR0_EL1]
mrs x17, contextidr_el1
mrs x9, vbar_el1
stp x17, x9, [x0, #CTX_CONTEXTIDR_EL1]
/* Save AArch32 system registers if the build has instructed so */
#if CTX_INCLUDE_AARCH32_REGS
mrs x11, spsr_abt
mrs x12, spsr_und
stp x11, x12, [x0, #CTX_SPSR_ABT]
mrs x13, spsr_irq
mrs x14, spsr_fiq
stp x13, x14, [x0, #CTX_SPSR_IRQ]
mrs x15, dacr32_el2
mrs x16, ifsr32_el2
stp x15, x16, [x0, #CTX_DACR32_EL2]
mrs x17, fpexc32_el2
str x17, [x0, #CTX_FP_FPEXC32_EL2]
#endif
/* Save NS timer registers if the build has instructed so */
#if NS_TIMER_SWITCH
mrs x10, cntp_ctl_el0
mrs x11, cntp_cval_el0
stp x10, x11, [x0, #CTX_CNTP_CTL_EL0]
mrs x12, cntv_ctl_el0
mrs x13, cntv_cval_el0
stp x12, x13, [x0, #CTX_CNTV_CTL_EL0]
mrs x14, cntkctl_el1
str x14, [x0, #CTX_CNTKCTL_EL1]
#endif
ret
endfunc el1_sysregs_context_save
/* -----------------------------------------------------
* The following function strictly follows the AArch64
* PCS to use x9-x17 (temporary caller-saved registers)
* to do post operations after saving the EL1 system
* register context.
* -----------------------------------------------------
*/
func el1_sysregs_context_save_post_ops
#if ENABLE_SPE_FOR_LOWER_ELS
/* Detect if SPE is implemented */
mrs x9, id_aa64dfr0_el1
ubfx x9, x9, #ID_AA64DFR0_PMS_SHIFT, #ID_AA64DFR0_PMS_LENGTH
cmp x9, #0x1
b.ne 1f
/*
* Before switching from normal world to secure world
* the profiling buffers need to be drained out to memory. This is
* required to avoid an invalid memory access when TTBR is switched
* for entry to SEL1.
*/
.arch armv8.2-a+profile
psb csync
dsb nsh
.arch armv8-a
1:
#endif
ret
endfunc el1_sysregs_context_save_post_ops
/* -----------------------------------------------------
* The following function strictly follows the AArch64
* PCS to use x9-x17 (temporary caller-saved registers)
* to restore EL1 system register context. It assumes
* that 'x0' is pointing to a 'el1_sys_regs' structure
* from where the register context will be restored
* -----------------------------------------------------
*/
func el1_sysregs_context_restore
ldp x9, x10, [x0, #CTX_SPSR_EL1]
msr spsr_el1, x9
msr elr_el1, x10
ldp x15, x16, [x0, #CTX_SCTLR_EL1]
msr sctlr_el1, x15
msr actlr_el1, x16
ldp x17, x9, [x0, #CTX_CPACR_EL1]
msr cpacr_el1, x17
msr csselr_el1, x9
ldp x10, x11, [x0, #CTX_SP_EL1]
msr sp_el1, x10
msr esr_el1, x11
ldp x12, x13, [x0, #CTX_TTBR0_EL1]
msr ttbr0_el1, x12
msr ttbr1_el1, x13
ldp x14, x15, [x0, #CTX_MAIR_EL1]
msr mair_el1, x14
msr amair_el1, x15
ldp x16, x17, [x0, #CTX_TCR_EL1]
msr tcr_el1, x16
msr tpidr_el1, x17
ldp x9, x10, [x0, #CTX_TPIDR_EL0]
msr tpidr_el0, x9
msr tpidrro_el0, x10
ldp x13, x14, [x0, #CTX_PAR_EL1]
msr par_el1, x13
msr far_el1, x14
ldp x15, x16, [x0, #CTX_AFSR0_EL1]
msr afsr0_el1, x15
msr afsr1_el1, x16
ldp x17, x9, [x0, #CTX_CONTEXTIDR_EL1]
msr contextidr_el1, x17
msr vbar_el1, x9
/* Restore AArch32 system registers if the build has instructed so */
#if CTX_INCLUDE_AARCH32_REGS
ldp x11, x12, [x0, #CTX_SPSR_ABT]
msr spsr_abt, x11
msr spsr_und, x12
ldp x13, x14, [x0, #CTX_SPSR_IRQ]
msr spsr_irq, x13
msr spsr_fiq, x14
ldp x15, x16, [x0, #CTX_DACR32_EL2]
msr dacr32_el2, x15
msr ifsr32_el2, x16
ldr x17, [x0, #CTX_FP_FPEXC32_EL2]
msr fpexc32_el2, x17
#endif
/* Restore NS timer registers if the build has instructed so */
#if NS_TIMER_SWITCH
ldp x10, x11, [x0, #CTX_CNTP_CTL_EL0]
msr cntp_ctl_el0, x10
msr cntp_cval_el0, x11
ldp x12, x13, [x0, #CTX_CNTV_CTL_EL0]
msr cntv_ctl_el0, x12
msr cntv_cval_el0, x13
ldr x14, [x0, #CTX_CNTKCTL_EL1]
msr cntkctl_el1, x14
#endif
/* No explict ISB required here as ERET covers it */
ret
endfunc el1_sysregs_context_restore
/* -----------------------------------------------------
* The following function follows the aapcs_64 strictly
* to use x9-x17 (temporary caller-saved registers
* according to AArch64 PCS) to save floating point
* register context. It assumes that 'x0' is pointing to
* a 'fp_regs' structure where the register context will
* be saved.
*
* Access to VFP registers will trap if CPTR_EL3.TFP is
* set. However currently we don't use VFP registers
* nor set traps in Trusted Firmware, and assume it's
* cleared
*
* TODO: Revisit when VFP is used in secure world
* -----------------------------------------------------
*/
#if CTX_INCLUDE_FPREGS
func fpregs_context_save
stp q0, q1, [x0, #CTX_FP_Q0]
stp q2, q3, [x0, #CTX_FP_Q2]
stp q4, q5, [x0, #CTX_FP_Q4]
stp q6, q7, [x0, #CTX_FP_Q6]
stp q8, q9, [x0, #CTX_FP_Q8]
stp q10, q11, [x0, #CTX_FP_Q10]
stp q12, q13, [x0, #CTX_FP_Q12]
stp q14, q15, [x0, #CTX_FP_Q14]
stp q16, q17, [x0, #CTX_FP_Q16]
stp q18, q19, [x0, #CTX_FP_Q18]
stp q20, q21, [x0, #CTX_FP_Q20]
stp q22, q23, [x0, #CTX_FP_Q22]
stp q24, q25, [x0, #CTX_FP_Q24]
stp q26, q27, [x0, #CTX_FP_Q26]
stp q28, q29, [x0, #CTX_FP_Q28]
stp q30, q31, [x0, #CTX_FP_Q30]
mrs x9, fpsr
str x9, [x0, #CTX_FP_FPSR]
mrs x10, fpcr
str x10, [x0, #CTX_FP_FPCR]
ret
endfunc fpregs_context_save
/* -----------------------------------------------------
* The following function follows the aapcs_64 strictly
* to use x9-x17 (temporary caller-saved registers
* according to AArch64 PCS) to restore floating point
* register context. It assumes that 'x0' is pointing to
* a 'fp_regs' structure from where the register context
* will be restored.
*
* Access to VFP registers will trap if CPTR_EL3.TFP is
* set. However currently we don't use VFP registers
* nor set traps in Trusted Firmware, and assume it's
* cleared
*
* TODO: Revisit when VFP is used in secure world
* -----------------------------------------------------
*/
func fpregs_context_restore
ldp q0, q1, [x0, #CTX_FP_Q0]
ldp q2, q3, [x0, #CTX_FP_Q2]
ldp q4, q5, [x0, #CTX_FP_Q4]
ldp q6, q7, [x0, #CTX_FP_Q6]
ldp q8, q9, [x0, #CTX_FP_Q8]
ldp q10, q11, [x0, #CTX_FP_Q10]
ldp q12, q13, [x0, #CTX_FP_Q12]
ldp q14, q15, [x0, #CTX_FP_Q14]
ldp q16, q17, [x0, #CTX_FP_Q16]
ldp q18, q19, [x0, #CTX_FP_Q18]
ldp q20, q21, [x0, #CTX_FP_Q20]
ldp q22, q23, [x0, #CTX_FP_Q22]
ldp q24, q25, [x0, #CTX_FP_Q24]
ldp q26, q27, [x0, #CTX_FP_Q26]
ldp q28, q29, [x0, #CTX_FP_Q28]
ldp q30, q31, [x0, #CTX_FP_Q30]
ldr x9, [x0, #CTX_FP_FPSR]
msr fpsr, x9
ldr x10, [x0, #CTX_FP_FPCR]
msr fpcr, x10
/*
* No explict ISB required here as ERET to
* switch to secure EL1 or non-secure world
* covers it
*/
ret
endfunc fpregs_context_restore
#endif /* CTX_INCLUDE_FPREGS */
/* -----------------------------------------------------
* The following functions are used to save and restore
* all the general purpose registers. Ideally we would
* only save and restore the callee saved registers when
* a world switch occurs but that type of implementation
* is more complex. So currently we will always save and
* restore these registers on entry and exit of EL3.
* These are not macros to ensure their invocation fits
* within the 32 instructions per exception vector.
* clobbers: x18
* -----------------------------------------------------
*/
func save_gp_registers
stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
stp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
stp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
stp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
stp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
stp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
stp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
stp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
stp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
stp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
stp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
stp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
stp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
stp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
mrs x18, sp_el0
str x18, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0]
ret
endfunc save_gp_registers
func restore_gp_registers_eret
ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0]
ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
b restore_gp_registers_callee_eret
endfunc restore_gp_registers_eret
func restore_gp_registers_callee_eret
ldp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4]
ldp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6]
ldp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8]
ldp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10]
ldp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12]
ldp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14]
ldp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18]
ldp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20]
ldp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22]
ldp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24]
ldp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26]
ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28]
ldp x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
msr sp_el0, x17
ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16]
eret
endfunc restore_gp_registers_callee_eret
/* -----------------------------------------------------
* This routine assumes that the SP_EL3 is pointing to
* a valid context structure from where the gp regs and
* other special registers can be retrieved.
* -----------------------------------------------------
*/
func el3_exit
/* -----------------------------------------------------
* Save the current SP_EL0 i.e. the EL3 runtime stack
* which will be used for handling the next SMC. Then
* switch to SP_EL3
* -----------------------------------------------------
*/
mov x17, sp
msr spsel, #1
str x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
/* -----------------------------------------------------
* Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET
* -----------------------------------------------------
*/
ldr x18, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]
ldp x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
msr scr_el3, x18
msr spsr_el3, x16
msr elr_el3, x17
/* Restore saved general purpose registers and return */
b restore_gp_registers_eret
endfunc el3_exit