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1 /*
2  * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #ifndef __CONTEXT_H__
8 #define __CONTEXT_H__
9 
10 /*******************************************************************************
11  * Constants that allow assembler code to access members of and the 'gp_regs'
12  * structure at their correct offsets.
13  ******************************************************************************/
14 #define CTX_GPREGS_OFFSET	U(0x0)
15 #define CTX_GPREG_X0		U(0x0)
16 #define CTX_GPREG_X1		U(0x8)
17 #define CTX_GPREG_X2		U(0x10)
18 #define CTX_GPREG_X3		U(0x18)
19 #define CTX_GPREG_X4		U(0x20)
20 #define CTX_GPREG_X5		U(0x28)
21 #define CTX_GPREG_X6		U(0x30)
22 #define CTX_GPREG_X7		U(0x38)
23 #define CTX_GPREG_X8		U(0x40)
24 #define CTX_GPREG_X9		U(0x48)
25 #define CTX_GPREG_X10		U(0x50)
26 #define CTX_GPREG_X11		U(0x58)
27 #define CTX_GPREG_X12		U(0x60)
28 #define CTX_GPREG_X13		U(0x68)
29 #define CTX_GPREG_X14		U(0x70)
30 #define CTX_GPREG_X15		U(0x78)
31 #define CTX_GPREG_X16		U(0x80)
32 #define CTX_GPREG_X17		U(0x88)
33 #define CTX_GPREG_X18		U(0x90)
34 #define CTX_GPREG_X19		U(0x98)
35 #define CTX_GPREG_X20		U(0xa0)
36 #define CTX_GPREG_X21		U(0xa8)
37 #define CTX_GPREG_X22		U(0xb0)
38 #define CTX_GPREG_X23		U(0xb8)
39 #define CTX_GPREG_X24		U(0xc0)
40 #define CTX_GPREG_X25		U(0xc8)
41 #define CTX_GPREG_X26		U(0xd0)
42 #define CTX_GPREG_X27		U(0xd8)
43 #define CTX_GPREG_X28		U(0xe0)
44 #define CTX_GPREG_X29		U(0xe8)
45 #define CTX_GPREG_LR		U(0xf0)
46 #define CTX_GPREG_SP_EL0	U(0xf8)
47 #define CTX_GPREGS_END		U(0x100)
48 
49 /*******************************************************************************
50  * Constants that allow assembler code to access members of and the 'el3_state'
51  * structure at their correct offsets. Note that some of the registers are only
52  * 32-bits wide but are stored as 64-bit values for convenience
53  ******************************************************************************/
54 #define CTX_EL3STATE_OFFSET	(CTX_GPREGS_OFFSET + CTX_GPREGS_END)
55 #define CTX_SCR_EL3		U(0x0)
56 #define CTX_RUNTIME_SP		U(0x8)
57 #define CTX_SPSR_EL3		U(0x10)
58 #define CTX_ELR_EL3		U(0x18)
59 #define CTX_EL3STATE_END	U(0x20)
60 
61 /*******************************************************************************
62  * Constants that allow assembler code to access members of and the
63  * 'el1_sys_regs' structure at their correct offsets. Note that some of the
64  * registers are only 32-bits wide but are stored as 64-bit values for
65  * convenience
66  ******************************************************************************/
67 #define CTX_SYSREGS_OFFSET	(CTX_EL3STATE_OFFSET + CTX_EL3STATE_END)
68 #define CTX_SPSR_EL1		U(0x0)
69 #define CTX_ELR_EL1		U(0x8)
70 #define CTX_SCTLR_EL1		U(0x10)
71 #define CTX_ACTLR_EL1		U(0x18)
72 #define CTX_CPACR_EL1		U(0x20)
73 #define CTX_CSSELR_EL1		U(0x28)
74 #define CTX_SP_EL1		U(0x30)
75 #define CTX_ESR_EL1		U(0x38)
76 #define CTX_TTBR0_EL1		U(0x40)
77 #define CTX_TTBR1_EL1		U(0x48)
78 #define CTX_MAIR_EL1		U(0x50)
79 #define CTX_AMAIR_EL1		U(0x58)
80 #define CTX_TCR_EL1		U(0x60)
81 #define CTX_TPIDR_EL1		U(0x68)
82 #define CTX_TPIDR_EL0		U(0x70)
83 #define CTX_TPIDRRO_EL0		U(0x78)
84 #define CTX_PAR_EL1		U(0x80)
85 #define CTX_FAR_EL1		U(0x88)
86 #define CTX_AFSR0_EL1		U(0x90)
87 #define CTX_AFSR1_EL1		U(0x98)
88 #define CTX_CONTEXTIDR_EL1	U(0xa0)
89 #define CTX_VBAR_EL1		U(0xa8)
90 #define CTX_PMCR_EL0		U(0xb0)
91 
92 /*
93  * If the platform is AArch64-only, there is no need to save and restore these
94  * AArch32 registers.
95  */
96 #if CTX_INCLUDE_AARCH32_REGS
97 #define CTX_SPSR_ABT		U(0xc0)  /* Align to the next 16 byte boundary */
98 #define CTX_SPSR_UND		U(0xc8)
99 #define CTX_SPSR_IRQ		U(0xd0)
100 #define CTX_SPSR_FIQ		U(0xd8)
101 #define CTX_DACR32_EL2		U(0xe0)
102 #define CTX_IFSR32_EL2		U(0xe8)
103 #define CTX_FP_FPEXC32_EL2	U(0xf0)
104 #define CTX_TIMER_SYSREGS_OFF	U(0x100) /* Align to the next 16 byte boundary */
105 #else
106 #define CTX_TIMER_SYSREGS_OFF	U(0xc0)  /* Align to the next 16 byte boundary */
107 #endif /* __CTX_INCLUDE_AARCH32_REGS__ */
108 
109 /*
110  * If the timer registers aren't saved and restored, we don't have to reserve
111  * space for them in the context
112  */
113 #if NS_TIMER_SWITCH
114 #define CTX_CNTP_CTL_EL0	(CTX_TIMER_SYSREGS_OFF + U(0x0))
115 #define CTX_CNTP_CVAL_EL0	(CTX_TIMER_SYSREGS_OFF + U(0x8))
116 #define CTX_CNTV_CTL_EL0	(CTX_TIMER_SYSREGS_OFF + U(0x10))
117 #define CTX_CNTV_CVAL_EL0	(CTX_TIMER_SYSREGS_OFF + U(0x18))
118 #define CTX_CNTKCTL_EL1		(CTX_TIMER_SYSREGS_OFF + U(0x20))
119 #define CTX_SYSREGS_END		(CTX_TIMER_SYSREGS_OFF + U(0x30)) /* Align to the next 16 byte boundary */
120 #else
121 #define CTX_SYSREGS_END		CTX_TIMER_SYSREGS_OFF
122 #endif /* __NS_TIMER_SWITCH__ */
123 
124 /*******************************************************************************
125  * Constants that allow assembler code to access members of and the 'fp_regs'
126  * structure at their correct offsets.
127  ******************************************************************************/
128 #if CTX_INCLUDE_FPREGS
129 #define CTX_FPREGS_OFFSET	(CTX_SYSREGS_OFFSET + CTX_SYSREGS_END)
130 #define CTX_FP_Q0		U(0x0)
131 #define CTX_FP_Q1		U(0x10)
132 #define CTX_FP_Q2		U(0x20)
133 #define CTX_FP_Q3		U(0x30)
134 #define CTX_FP_Q4		U(0x40)
135 #define CTX_FP_Q5		U(0x50)
136 #define CTX_FP_Q6		U(0x60)
137 #define CTX_FP_Q7		U(0x70)
138 #define CTX_FP_Q8		U(0x80)
139 #define CTX_FP_Q9		U(0x90)
140 #define CTX_FP_Q10		U(0xa0)
141 #define CTX_FP_Q11		U(0xb0)
142 #define CTX_FP_Q12		U(0xc0)
143 #define CTX_FP_Q13		U(0xd0)
144 #define CTX_FP_Q14		U(0xe0)
145 #define CTX_FP_Q15		U(0xf0)
146 #define CTX_FP_Q16		U(0x100)
147 #define CTX_FP_Q17		U(0x110)
148 #define CTX_FP_Q18		U(0x120)
149 #define CTX_FP_Q19		U(0x130)
150 #define CTX_FP_Q20		U(0x140)
151 #define CTX_FP_Q21		U(0x150)
152 #define CTX_FP_Q22		U(0x160)
153 #define CTX_FP_Q23		U(0x170)
154 #define CTX_FP_Q24		U(0x180)
155 #define CTX_FP_Q25		U(0x190)
156 #define CTX_FP_Q26		U(0x1a0)
157 #define CTX_FP_Q27		U(0x1b0)
158 #define CTX_FP_Q28		U(0x1c0)
159 #define CTX_FP_Q29		U(0x1d0)
160 #define CTX_FP_Q30		U(0x1e0)
161 #define CTX_FP_Q31		U(0x1f0)
162 #define CTX_FP_FPSR		U(0x200)
163 #define CTX_FP_FPCR		U(0x208)
164 #define CTX_FPREGS_END		U(0x210)
165 #endif
166 
167 #ifndef __ASSEMBLY__
168 
169 #include <cassert.h>
170 #include <platform_def.h>	/* for CACHE_WRITEBACK_GRANULE */
171 #include <stdint.h>
172 
173 /*
174  * Common constants to help define the 'cpu_context' structure and its
175  * members below.
176  */
177 #define DWORD_SHIFT		U(3)
178 #define DEFINE_REG_STRUCT(name, num_regs)	\
179 	typedef struct name {			\
180 		uint64_t _regs[num_regs];	\
181 	}  __aligned(16) name##_t
182 
183 /* Constants to determine the size of individual context structures */
184 #define CTX_GPREG_ALL		(CTX_GPREGS_END >> DWORD_SHIFT)
185 #define CTX_SYSREG_ALL		(CTX_SYSREGS_END >> DWORD_SHIFT)
186 #if CTX_INCLUDE_FPREGS
187 #define CTX_FPREG_ALL		(CTX_FPREGS_END >> DWORD_SHIFT)
188 #endif
189 #define CTX_EL3STATE_ALL	(CTX_EL3STATE_END >> DWORD_SHIFT)
190 
191 /*
192  * AArch64 general purpose register context structure. Usually x0-x18,
193  * lr are saved as the compiler is expected to preserve the remaining
194  * callee saved registers if used by the C runtime and the assembler
195  * does not touch the remaining. But in case of world switch during
196  * exception handling, we need to save the callee registers too.
197  */
198 DEFINE_REG_STRUCT(gp_regs, CTX_GPREG_ALL);
199 
200 /*
201  * AArch64 EL1 system register context structure for preserving the
202  * architectural state during switches from one security state to
203  * another in EL1.
204  */
205 DEFINE_REG_STRUCT(el1_sys_regs, CTX_SYSREG_ALL);
206 
207 /*
208  * AArch64 floating point register context structure for preserving
209  * the floating point state during switches from one security state to
210  * another.
211  */
212 #if CTX_INCLUDE_FPREGS
213 DEFINE_REG_STRUCT(fp_regs, CTX_FPREG_ALL);
214 #endif
215 
216 /*
217  * Miscellaneous registers used by EL3 firmware to maintain its state
218  * across exception entries and exits
219  */
220 DEFINE_REG_STRUCT(el3_state, CTX_EL3STATE_ALL);
221 
222 /*
223  * Macros to access members of any of the above structures using their
224  * offsets
225  */
226 #define read_ctx_reg(ctx, offset)	((ctx)->_regs[offset >> DWORD_SHIFT])
227 #define write_ctx_reg(ctx, offset, val)	(((ctx)->_regs[offset >> DWORD_SHIFT]) \
228 					 = val)
229 
230 /*
231  * Top-level context structure which is used by EL3 firmware to
232  * preserve the state of a core at EL1 in one of the two security
233  * states and save enough EL3 meta data to be able to return to that
234  * EL and security state. The context management library will be used
235  * to ensure that SP_EL3 always points to an instance of this
236  * structure at exception entry and exit. Each instance will
237  * correspond to either the secure or the non-secure state.
238  */
239 typedef struct cpu_context {
240 	gp_regs_t gpregs_ctx;
241 	el3_state_t el3state_ctx;
242 	el1_sys_regs_t sysregs_ctx;
243 #if CTX_INCLUDE_FPREGS
244 	fp_regs_t fpregs_ctx;
245 #endif
246 } cpu_context_t;
247 
248 /* Macros to access members of the 'cpu_context_t' structure */
249 #define get_el3state_ctx(h)	(&((cpu_context_t *) h)->el3state_ctx)
250 #if CTX_INCLUDE_FPREGS
251 #define get_fpregs_ctx(h)	(&((cpu_context_t *) h)->fpregs_ctx)
252 #endif
253 #define get_sysregs_ctx(h)	(&((cpu_context_t *) h)->sysregs_ctx)
254 #define get_gpregs_ctx(h)	(&((cpu_context_t *) h)->gpregs_ctx)
255 
256 /*
257  * Compile time assertions related to the 'cpu_context' structure to
258  * ensure that the assembler and the compiler view of the offsets of
259  * the structure members is the same.
260  */
261 CASSERT(CTX_GPREGS_OFFSET == __builtin_offsetof(cpu_context_t, gpregs_ctx), \
262 	assert_core_context_gp_offset_mismatch);
263 CASSERT(CTX_SYSREGS_OFFSET == __builtin_offsetof(cpu_context_t, sysregs_ctx), \
264 	assert_core_context_sys_offset_mismatch);
265 #if CTX_INCLUDE_FPREGS
266 CASSERT(CTX_FPREGS_OFFSET == __builtin_offsetof(cpu_context_t, fpregs_ctx), \
267 	assert_core_context_fp_offset_mismatch);
268 #endif
269 CASSERT(CTX_EL3STATE_OFFSET == __builtin_offsetof(cpu_context_t, el3state_ctx), \
270 	assert_core_context_el3state_offset_mismatch);
271 
272 /*
273  * Helper macro to set the general purpose registers that correspond to
274  * parameters in an aapcs_64 call i.e. x0-x7
275  */
276 #define set_aapcs_args0(ctx, x0)				do {	\
277 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X0, x0);	\
278 	} while (0)
279 #define set_aapcs_args1(ctx, x0, x1)				do {	\
280 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X1, x1);	\
281 		set_aapcs_args0(ctx, x0);				\
282 	} while (0)
283 #define set_aapcs_args2(ctx, x0, x1, x2)			do {	\
284 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X2, x2);	\
285 		set_aapcs_args1(ctx, x0, x1);				\
286 	} while (0)
287 #define set_aapcs_args3(ctx, x0, x1, x2, x3)			do {	\
288 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X3, x3);	\
289 		set_aapcs_args2(ctx, x0, x1, x2);			\
290 	} while (0)
291 #define set_aapcs_args4(ctx, x0, x1, x2, x3, x4)		do {	\
292 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X4, x4);	\
293 		set_aapcs_args3(ctx, x0, x1, x2, x3);			\
294 	} while (0)
295 #define set_aapcs_args5(ctx, x0, x1, x2, x3, x4, x5)		do {	\
296 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X5, x5);	\
297 		set_aapcs_args4(ctx, x0, x1, x2, x3, x4);		\
298 	} while (0)
299 #define set_aapcs_args6(ctx, x0, x1, x2, x3, x4, x5, x6)	do {	\
300 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X6, x6);	\
301 		set_aapcs_args5(ctx, x0, x1, x2, x3, x4, x5);		\
302 	} while (0)
303 #define set_aapcs_args7(ctx, x0, x1, x2, x3, x4, x5, x6, x7)	do {	\
304 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X7, x7);	\
305 		set_aapcs_args6(ctx, x0, x1, x2, x3, x4, x5, x6);	\
306 	} while (0)
307 
308 /*******************************************************************************
309  * Function prototypes
310  ******************************************************************************/
311 void el1_sysregs_context_save(el1_sys_regs_t *regs);
312 void el1_sysregs_context_save_post_ops(void);
313 void el1_sysregs_context_restore(el1_sys_regs_t *regs);
314 #if CTX_INCLUDE_FPREGS
315 void fpregs_context_save(fp_regs_t *regs);
316 void fpregs_context_restore(fp_regs_t *regs);
317 #endif
318 
319 
320 #undef CTX_SYSREG_ALL
321 #if CTX_INCLUDE_FPREGS
322 #undef CTX_FPREG_ALL
323 #endif
324 #undef CTX_GPREG_ALL
325 #undef CTX_EL3STATE_ALL
326 
327 #endif /* __ASSEMBLY__ */
328 
329 #endif /* __CONTEXT_H__ */
330