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      1 /*
      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 
     31 #ifndef __CONTEXT_H__
     32 #define __CONTEXT_H__
     33 
     34 /*******************************************************************************
     35  * Constants that allow assembler code to access members of and the 'gp_regs'
     36  * structure at their correct offsets.
     37  ******************************************************************************/
     38 #define CTX_GPREGS_OFFSET	0x0
     39 #define CTX_GPREG_X0		0x0
     40 #define CTX_GPREG_X1		0x8
     41 #define CTX_GPREG_X2		0x10
     42 #define CTX_GPREG_X3		0x18
     43 #define CTX_GPREG_X4		0x20
     44 #define CTX_GPREG_X5		0x28
     45 #define CTX_GPREG_X6		0x30
     46 #define CTX_GPREG_X7		0x38
     47 #define CTX_GPREG_X8		0x40
     48 #define CTX_GPREG_X9		0x48
     49 #define CTX_GPREG_X10		0x50
     50 #define CTX_GPREG_X11		0x58
     51 #define CTX_GPREG_X12		0x60
     52 #define CTX_GPREG_X13		0x68
     53 #define CTX_GPREG_X14		0x70
     54 #define CTX_GPREG_X15		0x78
     55 #define CTX_GPREG_X16		0x80
     56 #define CTX_GPREG_X17		0x88
     57 #define CTX_GPREG_X18		0x90
     58 #define CTX_GPREG_X19		0x98
     59 #define CTX_GPREG_X20		0xa0
     60 #define CTX_GPREG_X21		0xa8
     61 #define CTX_GPREG_X22		0xb0
     62 #define CTX_GPREG_X23		0xb8
     63 #define CTX_GPREG_X24		0xc0
     64 #define CTX_GPREG_X25		0xc8
     65 #define CTX_GPREG_X26		0xd0
     66 #define CTX_GPREG_X27		0xd8
     67 #define CTX_GPREG_X28		0xe0
     68 #define CTX_GPREG_X29		0xe8
     69 #define CTX_GPREG_LR		0xf0
     70 #define CTX_GPREG_SP_EL0	0xf8
     71 #define CTX_GPREGS_END		0x100
     72 
     73 /*******************************************************************************
     74  * Constants that allow assembler code to access members of and the 'el3_state'
     75  * structure at their correct offsets. Note that some of the registers are only
     76  * 32-bits wide but are stored as 64-bit values for convenience
     77  ******************************************************************************/
     78 #define CTX_EL3STATE_OFFSET	(CTX_GPREGS_OFFSET + CTX_GPREGS_END)
     79 #define CTX_SCR_EL3		0x0
     80 #define CTX_RUNTIME_SP		0x8
     81 #define CTX_SPSR_EL3		0x10
     82 #define CTX_ELR_EL3		0x18
     83 #define CTX_EL3STATE_END	0x20
     84 
     85 /*******************************************************************************
     86  * Constants that allow assembler code to access members of and the
     87  * 'el1_sys_regs' structure at their correct offsets. Note that some of the
     88  * registers are only 32-bits wide but are stored as 64-bit values for
     89  * convenience
     90  ******************************************************************************/
     91 #define CTX_SYSREGS_OFFSET	(CTX_EL3STATE_OFFSET + CTX_EL3STATE_END)
     92 #define CTX_SPSR_EL1		0x0
     93 #define CTX_ELR_EL1		0x8
     94 #define CTX_SPSR_ABT		0x10
     95 #define CTX_SPSR_UND		0x18
     96 #define CTX_SPSR_IRQ		0x20
     97 #define CTX_SPSR_FIQ		0x28
     98 #define CTX_SCTLR_EL1		0x30
     99 #define CTX_ACTLR_EL1		0x38
    100 #define CTX_CPACR_EL1		0x40
    101 #define CTX_CSSELR_EL1		0x48
    102 #define CTX_SP_EL1		0x50
    103 #define CTX_ESR_EL1		0x58
    104 #define CTX_TTBR0_EL1		0x60
    105 #define CTX_TTBR1_EL1		0x68
    106 #define CTX_MAIR_EL1		0x70
    107 #define CTX_AMAIR_EL1		0x78
    108 #define CTX_TCR_EL1		0x80
    109 #define CTX_TPIDR_EL1		0x88
    110 #define CTX_TPIDR_EL0		0x90
    111 #define CTX_TPIDRRO_EL0		0x98
    112 #define CTX_DACR32_EL2		0xa0
    113 #define CTX_IFSR32_EL2		0xa8
    114 #define CTX_PAR_EL1		0xb0
    115 #define CTX_FAR_EL1		0xb8
    116 #define CTX_AFSR0_EL1		0xc0
    117 #define CTX_AFSR1_EL1		0xc8
    118 #define CTX_CONTEXTIDR_EL1	0xd0
    119 #define CTX_VBAR_EL1		0xd8
    120 /*
    121  * If the timer registers aren't saved and restored, we don't have to reserve
    122  * space for them in the context
    123  */
    124 #if NS_TIMER_SWITCH
    125 #define CTX_CNTP_CTL_EL0	0xe0
    126 #define CTX_CNTP_CVAL_EL0	0xe8
    127 #define CTX_CNTV_CTL_EL0	0xf0
    128 #define CTX_CNTV_CVAL_EL0	0xf8
    129 #define CTX_CNTKCTL_EL1		0x100
    130 #define CTX_FP_FPEXC32_EL2	0x108
    131 #define CTX_SYSREGS_END		0x110
    132 #else
    133 #define CTX_FP_FPEXC32_EL2	0xe0
    134 #define CTX_SYSREGS_END		0xf0
    135 #endif
    136 
    137 /*******************************************************************************
    138  * Constants that allow assembler code to access members of and the 'fp_regs'
    139  * structure at their correct offsets.
    140  ******************************************************************************/
    141 #if CTX_INCLUDE_FPREGS
    142 #define CTX_FPREGS_OFFSET	(CTX_SYSREGS_OFFSET + CTX_SYSREGS_END)
    143 #define CTX_FP_Q0		0x0
    144 #define CTX_FP_Q1		0x10
    145 #define CTX_FP_Q2		0x20
    146 #define CTX_FP_Q3		0x30
    147 #define CTX_FP_Q4		0x40
    148 #define CTX_FP_Q5		0x50
    149 #define CTX_FP_Q6		0x60
    150 #define CTX_FP_Q7		0x70
    151 #define CTX_FP_Q8		0x80
    152 #define CTX_FP_Q9		0x90
    153 #define CTX_FP_Q10		0xa0
    154 #define CTX_FP_Q11		0xb0
    155 #define CTX_FP_Q12		0xc0
    156 #define CTX_FP_Q13		0xd0
    157 #define CTX_FP_Q14		0xe0
    158 #define CTX_FP_Q15		0xf0
    159 #define CTX_FP_Q16		0x100
    160 #define CTX_FP_Q17		0x110
    161 #define CTX_FP_Q18		0x120
    162 #define CTX_FP_Q19		0x130
    163 #define CTX_FP_Q20		0x140
    164 #define CTX_FP_Q21		0x150
    165 #define CTX_FP_Q22		0x160
    166 #define CTX_FP_Q23		0x170
    167 #define CTX_FP_Q24		0x180
    168 #define CTX_FP_Q25		0x190
    169 #define CTX_FP_Q26		0x1a0
    170 #define CTX_FP_Q27		0x1b0
    171 #define CTX_FP_Q28		0x1c0
    172 #define CTX_FP_Q29		0x1d0
    173 #define CTX_FP_Q30		0x1e0
    174 #define CTX_FP_Q31		0x1f0
    175 #define CTX_FP_FPSR		0x200
    176 #define CTX_FP_FPCR		0x208
    177 #define CTX_FPREGS_END		0x210
    178 #endif
    179 
    180 #ifndef __ASSEMBLY__
    181 
    182 #include <cassert.h>
    183 #include <platform_def.h>	/* for CACHE_WRITEBACK_GRANULE */
    184 #include <stdint.h>
    185 
    186 /*
    187  * Common constants to help define the 'cpu_context' structure and its
    188  * members below.
    189  */
    190 #define DWORD_SHIFT		3
    191 #define DEFINE_REG_STRUCT(name, num_regs)	\
    192 	typedef struct name {			\
    193 		uint64_t _regs[num_regs];	\
    194 	}  __aligned(16) name##_t
    195 
    196 /* Constants to determine the size of individual context structures */
    197 #define CTX_GPREG_ALL		(CTX_GPREGS_END >> DWORD_SHIFT)
    198 #define CTX_SYSREG_ALL		(CTX_SYSREGS_END >> DWORD_SHIFT)
    199 #if CTX_INCLUDE_FPREGS
    200 #define CTX_FPREG_ALL		(CTX_FPREGS_END >> DWORD_SHIFT)
    201 #endif
    202 #define CTX_EL3STATE_ALL	(CTX_EL3STATE_END >> DWORD_SHIFT)
    203 
    204 /*
    205  * AArch64 general purpose register context structure. Usually x0-x18,
    206  * lr are saved as the compiler is expected to preserve the remaining
    207  * callee saved registers if used by the C runtime and the assembler
    208  * does not touch the remaining. But in case of world switch during
    209  * exception handling, we need to save the callee registers too.
    210  */
    211 DEFINE_REG_STRUCT(gp_regs, CTX_GPREG_ALL);
    212 
    213 /*
    214  * AArch64 EL1 system register context structure for preserving the
    215  * architectural state during switches from one security state to
    216  * another in EL1.
    217  */
    218 DEFINE_REG_STRUCT(el1_sys_regs, CTX_SYSREG_ALL);
    219 
    220 /*
    221  * AArch64 floating point register context structure for preserving
    222  * the floating point state during switches from one security state to
    223  * another.
    224  */
    225 #if CTX_INCLUDE_FPREGS
    226 DEFINE_REG_STRUCT(fp_regs, CTX_FPREG_ALL);
    227 #endif
    228 
    229 /*
    230  * Miscellaneous registers used by EL3 firmware to maintain its state
    231  * across exception entries and exits
    232  */
    233 DEFINE_REG_STRUCT(el3_state, CTX_EL3STATE_ALL);
    234 
    235 /*
    236  * Macros to access members of any of the above structures using their
    237  * offsets
    238  */
    239 #define read_ctx_reg(ctx, offset)	((ctx)->_regs[offset >> DWORD_SHIFT])
    240 #define write_ctx_reg(ctx, offset, val)	(((ctx)->_regs[offset >> DWORD_SHIFT]) \
    241 					 = val)
    242 
    243 /*
    244  * Top-level context structure which is used by EL3 firmware to
    245  * preserve the state of a core at EL1 in one of the two security
    246  * states and save enough EL3 meta data to be able to return to that
    247  * EL and security state. The context management library will be used
    248  * to ensure that SP_EL3 always points to an instance of this
    249  * structure at exception entry and exit. Each instance will
    250  * correspond to either the secure or the non-secure state.
    251  */
    252 typedef struct cpu_context {
    253 	gp_regs_t gpregs_ctx;
    254 	el3_state_t el3state_ctx;
    255 	el1_sys_regs_t sysregs_ctx;
    256 #if CTX_INCLUDE_FPREGS
    257 	fp_regs_t fpregs_ctx;
    258 #endif
    259 } cpu_context_t;
    260 
    261 /* Macros to access members of the 'cpu_context_t' structure */
    262 #define get_el3state_ctx(h)	(&((cpu_context_t *) h)->el3state_ctx)
    263 #if CTX_INCLUDE_FPREGS
    264 #define get_fpregs_ctx(h)	(&((cpu_context_t *) h)->fpregs_ctx)
    265 #endif
    266 #define get_sysregs_ctx(h)	(&((cpu_context_t *) h)->sysregs_ctx)
    267 #define get_gpregs_ctx(h)	(&((cpu_context_t *) h)->gpregs_ctx)
    268 
    269 /*
    270  * Compile time assertions related to the 'cpu_context' structure to
    271  * ensure that the assembler and the compiler view of the offsets of
    272  * the structure members is the same.
    273  */
    274 CASSERT(CTX_GPREGS_OFFSET == __builtin_offsetof(cpu_context_t, gpregs_ctx), \
    275 	assert_core_context_gp_offset_mismatch);
    276 CASSERT(CTX_SYSREGS_OFFSET == __builtin_offsetof(cpu_context_t, sysregs_ctx), \
    277 	assert_core_context_sys_offset_mismatch);
    278 #if CTX_INCLUDE_FPREGS
    279 CASSERT(CTX_FPREGS_OFFSET == __builtin_offsetof(cpu_context_t, fpregs_ctx), \
    280 	assert_core_context_fp_offset_mismatch);
    281 #endif
    282 CASSERT(CTX_EL3STATE_OFFSET == __builtin_offsetof(cpu_context_t, el3state_ctx), \
    283 	assert_core_context_el3state_offset_mismatch);
    284 
    285 /*
    286  * Helper macro to set the general purpose registers that correspond to
    287  * parameters in an aapcs_64 call i.e. x0-x7
    288  */
    289 #define set_aapcs_args0(ctx, x0)				do {	\
    290 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X0, x0);	\
    291 	} while (0);
    292 #define set_aapcs_args1(ctx, x0, x1)				do {	\
    293 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X1, x1);	\
    294 		set_aapcs_args0(ctx, x0);				\
    295 	} while (0);
    296 #define set_aapcs_args2(ctx, x0, x1, x2)			do {	\
    297 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X2, x2);	\
    298 		set_aapcs_args1(ctx, x0, x1);				\
    299 	} while (0);
    300 #define set_aapcs_args3(ctx, x0, x1, x2, x3)			do {	\
    301 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X3, x3);	\
    302 		set_aapcs_args2(ctx, x0, x1, x2);			\
    303 	} while (0);
    304 #define set_aapcs_args4(ctx, x0, x1, x2, x3, x4)		do {	\
    305 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X4, x4);	\
    306 		set_aapcs_args3(ctx, x0, x1, x2, x3);			\
    307 	} while (0);
    308 #define set_aapcs_args5(ctx, x0, x1, x2, x3, x4, x5)		do {	\
    309 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X5, x5);	\
    310 		set_aapcs_args4(ctx, x0, x1, x2, x3, x4);		\
    311 	} while (0);
    312 #define set_aapcs_args6(ctx, x0, x1, x2, x3, x4, x5, x6)	do {	\
    313 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X6, x6);	\
    314 		set_aapcs_args5(ctx, x0, x1, x2, x3, x4, x5);		\
    315 	} while (0);
    316 #define set_aapcs_args7(ctx, x0, x1, x2, x3, x4, x5, x6, x7)	do {	\
    317 		write_ctx_reg(get_gpregs_ctx(ctx), CTX_GPREG_X7, x7);	\
    318 		set_aapcs_args6(ctx, x0, x1, x2, x3, x4, x5, x6);	\
    319 	} while (0);
    320 
    321 /*******************************************************************************
    322  * Function prototypes
    323  ******************************************************************************/
    324 void el1_sysregs_context_save(el1_sys_regs_t *regs);
    325 void el1_sysregs_context_restore(el1_sys_regs_t *regs);
    326 #if CTX_INCLUDE_FPREGS
    327 void fpregs_context_save(fp_regs_t *regs);
    328 void fpregs_context_restore(fp_regs_t *regs);
    329 #endif
    330 
    331 
    332 #undef CTX_SYSREG_ALL
    333 #if CTX_INCLUDE_FPREGS
    334 #undef CTX_FPREG_ALL
    335 #endif
    336 #undef CTX_GPREG_ALL
    337 #undef CTX_EL3STATE_ALL
    338 
    339 #endif /* __ASSEMBLY__ */
    340 
    341 #endif /* __CONTEXT_H__ */
    342