xref: /openbmc/linux/arch/powerpc/include/asm/sstep.h (revision c545b9f0)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
4  */
5 #include <asm/inst.h>
6 
7 struct pt_regs;
8 
9 /*
10  * We don't allow single-stepping an mtmsrd that would clear
11  * MSR_RI, since that would make the exception unrecoverable.
12  * Since we need to single-step to proceed from a breakpoint,
13  * we don't allow putting a breakpoint on an mtmsrd instruction.
14  * Similarly we don't allow breakpoints on rfid instructions.
15  * These macros tell us if an instruction is a mtmsrd or rfid.
16  * Note that these return true for both mtmsr/rfi (32-bit)
17  * and mtmsrd/rfid (64-bit).
18  */
19 #define IS_MTMSRD(instr)	((ppc_inst_val(instr) & 0xfc0007be) == 0x7c000124)
20 #define IS_RFID(instr)		((ppc_inst_val(instr) & 0xfc0007be) == 0x4c000024)
21 
22 enum instruction_type {
23 	COMPUTE,		/* arith/logical/CR op, etc. */
24 	LOAD,			/* load and store types need to be contiguous */
25 	LOAD_MULTI,
26 	LOAD_FP,
27 	LOAD_VMX,
28 	LOAD_VSX,
29 	STORE,
30 	STORE_MULTI,
31 	STORE_FP,
32 	STORE_VMX,
33 	STORE_VSX,
34 	LARX,
35 	STCX,
36 	BRANCH,
37 	MFSPR,
38 	MTSPR,
39 	CACHEOP,
40 	BARRIER,
41 	SYSCALL,
42 	SYSCALL_VECTORED_0,
43 	MFMSR,
44 	MTMSR,
45 	RFI,
46 	INTERRUPT,
47 	UNKNOWN
48 };
49 
50 #define INSTR_TYPE_MASK	0x1f
51 
52 #define OP_IS_LOAD(type)	((LOAD <= (type) && (type) <= LOAD_VSX) || (type) == LARX)
53 #define OP_IS_STORE(type)	((STORE <= (type) && (type) <= STORE_VSX) || (type) == STCX)
54 #define OP_IS_LOAD_STORE(type)	(LOAD <= (type) && (type) <= STCX)
55 
56 /* Compute flags, ORed in with type */
57 #define SETREG		0x20
58 #define SETCC		0x40
59 #define SETXER		0x80
60 
61 /* Branch flags, ORed in with type */
62 #define SETLK		0x20
63 #define BRTAKEN		0x40
64 #define DECCTR		0x80
65 
66 /* Load/store flags, ORed in with type */
67 #define SIGNEXT		0x20
68 #define UPDATE		0x40	/* matches bit in opcode 31 instructions */
69 #define BYTEREV		0x80
70 #define FPCONV		0x100
71 
72 /* Barrier type field, ORed in with type */
73 #define BARRIER_MASK	0xe0
74 #define BARRIER_SYNC	0x00
75 #define BARRIER_ISYNC	0x20
76 #define BARRIER_EIEIO	0x40
77 #define BARRIER_LWSYNC	0x60
78 #define BARRIER_PTESYNC	0x80
79 
80 /* Cacheop values, ORed in with type */
81 #define CACHEOP_MASK	0x700
82 #define DCBST		0
83 #define DCBF		0x100
84 #define DCBTST		0x200
85 #define DCBT		0x300
86 #define ICBI		0x400
87 #define DCBZ		0x500
88 
89 /* VSX flags values */
90 #define VSX_FPCONV	1	/* do floating point SP/DP conversion */
91 #define VSX_SPLAT	2	/* store loaded value into all elements */
92 #define VSX_LDLEFT	4	/* load VSX register from left */
93 #define VSX_CHECK_VEC	8	/* check MSR_VEC not MSR_VSX for reg >= 32 */
94 
95 /* Prefixed flag, ORed in with type */
96 #define PREFIXED       0x800
97 
98 /* Size field in type word */
99 #define SIZE(n)		((n) << 12)
100 #define GETSIZE(w)	((w) >> 12)
101 
102 #define GETTYPE(t)	((t) & INSTR_TYPE_MASK)
103 #define GETLENGTH(t)   (((t) & PREFIXED) ? 8 : 4)
104 
105 #define MKOP(t, f, s)	((t) | (f) | SIZE(s))
106 
107 /* Prefix instruction operands */
108 #define GET_PREFIX_RA(i)	(((i) >> 16) & 0x1f)
109 #define GET_PREFIX_R(i)		((i) & (1ul << 20))
110 
111 extern s32 patch__exec_instr;
112 
113 struct instruction_op {
114 	int type;
115 	int reg;
116 	unsigned long val;
117 	/* For LOAD/STORE/LARX/STCX */
118 	unsigned long ea;
119 	int update_reg;
120 	/* For MFSPR */
121 	int spr;
122 	u32 ccval;
123 	u32 xerval;
124 	u8 element_size;	/* for VSX/VMX loads/stores */
125 	u8 vsx_flags;
126 };
127 
128 union vsx_reg {
129 	u8	b[16];
130 	u16	h[8];
131 	u32	w[4];
132 	unsigned long d[2];
133 	float	fp[4];
134 	double	dp[2];
135 	__vector128 v;
136 };
137 
138 /*
139  * Decode an instruction, and return information about it in *op
140  * without changing *regs.
141  *
142  * Return value is 1 if the instruction can be emulated just by
143  * updating *regs with the information in *op, -1 if we need the
144  * GPRs but *regs doesn't contain the full register set, or 0
145  * otherwise.
146  */
147 extern int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
148 			 ppc_inst_t instr);
149 
150 /*
151  * Emulate an instruction that can be executed just by updating
152  * fields in *regs.
153  */
154 void emulate_update_regs(struct pt_regs *reg, struct instruction_op *op);
155 
156 /*
157  * Emulate instructions that cause a transfer of control,
158  * arithmetic/logical instructions, loads and stores,
159  * cache operations and barriers.
160  *
161  * Returns 1 if the instruction was emulated successfully,
162  * 0 if it could not be emulated, or -1 for an instruction that
163  * should not be emulated (rfid, mtmsrd clearing MSR_RI, etc.).
164  */
165 int emulate_step(struct pt_regs *regs, ppc_inst_t instr);
166 
167 /*
168  * Emulate a load or store instruction by reading/writing the
169  * memory of the current process.  FP/VMX/VSX registers are assumed
170  * to hold live values if the appropriate enable bit in regs->msr is
171  * set; otherwise this will use the saved values in the thread struct
172  * for user-mode accesses.
173  */
174 extern int emulate_loadstore(struct pt_regs *regs, struct instruction_op *op);
175 
176 extern void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg,
177 			     const void *mem, bool cross_endian);
178 extern void emulate_vsx_store(struct instruction_op *op,
179 			      const union vsx_reg *reg, void *mem,
180 			      bool cross_endian);
181 extern int emulate_dcbz(unsigned long ea, struct pt_regs *regs);
182