1 /* SPDX-License-Identifier: GPL-2.0-or-later *
2 /*
3 * Code to prepare detour buffer for optprobes
4 *
5 * Copyright 2017, Anju T, IBM Corp.
6 */
7
8 #include <asm/ppc_asm.h>
9 #include <asm/ptrace.h>
10 #include <asm/asm-offsets.h>
11
12 #ifdef CONFIG_PPC64
13 #define SAVE_30GPRS(base) SAVE_GPRS(2, 31, bas
14 #define REST_30GPRS(base) REST_GPRS(2, 31, bas
15 #define TEMPLATE_FOR_IMM_LOAD_INSNS nop; n
16 #else
17 #define SAVE_30GPRS(base) stmw r2, GPR2(base)
18 #define REST_30GPRS(base) lmw r2, GPR2(base)
19 #define TEMPLATE_FOR_IMM_LOAD_INSNS nop; n
20 #endif
21
22 #define OPT_SLOT_SIZE 65536
23
24 .balign 4
25
26 /*
27 * Reserve an area to allocate slots f
28 * This is part of .text section (rath
29 * as this needs to be within 32MB of
30 */
31 .global optinsn_slot
32 optinsn_slot:
33 .space OPT_SLOT_SIZE
34
35 /*
36 * Optprobe template:
37 * This template gets copied into one
38 * and gets fixed up with real optprob
39 */
40 .global optprobe_template_entry
41 optprobe_template_entry:
42 /* Create an in-memory pt_regs */
43 PPC_STLU r1,-INT_FRAME_SIZE(r1)
44 SAVE_GPR(0,r1)
45 /* Save the previous SP into stack */
46 addi r0,r1,INT_FRAME_SIZE
47 PPC_STL r0,GPR1(r1)
48 SAVE_30GPRS(r1)
49 /* Save SPRS */
50 mfmsr r5
51 PPC_STL r5,_MSR(r1)
52 li r5,0x700
53 PPC_STL r5,_TRAP(r1)
54 li r5,0
55 PPC_STL r5,ORIG_GPR3(r1)
56 PPC_STL r5,RESULT(r1)
57 mfctr r5
58 PPC_STL r5,_CTR(r1)
59 mflr r5
60 PPC_STL r5,_LINK(r1)
61 mfspr r5,SPRN_XER
62 PPC_STL r5,_XER(r1)
63 mfcr r5
64 PPC_STL r5,_CCR(r1)
65 #ifdef CONFIG_PPC64
66 lbz r5,PACAIRQSOFTMASK(r13)
67 std r5,SOFTE(r1)
68 #endif
69
70 /*
71 * We may get here from a module, so l
72 * The original TOC gets restored when
73 * further below.
74 */
75 #ifdef CONFIG_PPC64
76 LOAD_PACA_TOC()
77 #endif
78
79 .global optprobe_template_op_address
80 optprobe_template_op_address:
81 /*
82 * Parameters to optimized_callback():
83 * 1. optimized_kprobe structure in r3
84 */
85 TEMPLATE_FOR_IMM_LOAD_INSNS
86
87 /* 2. pt_regs pointer in r4 */
88 addi r4,r1,STACK_INT_FRAME_REGS
89
90 .global optprobe_template_call_handler
91 optprobe_template_call_handler:
92 /* Branch to optimized_callback() */
93 nop
94
95 /*
96 * Parameters for instruction emulatio
97 * 1. Pass SP in register r3.
98 */
99 addi r3,r1,STACK_INT_FRAME_REGS
100
101 .global optprobe_template_insn
102 optprobe_template_insn:
103 /* 2, Pass instruction to be emulated
104 TEMPLATE_FOR_IMM_LOAD_INSNS
105
106 .global optprobe_template_call_emulate
107 optprobe_template_call_emulate:
108 /* Branch to emulate_step() */
109 nop
110
111 /*
112 * All done.
113 * Now, restore the registers...
114 */
115 PPC_LL r5,_MSR(r1)
116 mtmsr r5
117 PPC_LL r5,_CTR(r1)
118 mtctr r5
119 PPC_LL r5,_LINK(r1)
120 mtlr r5
121 PPC_LL r5,_XER(r1)
122 mtxer r5
123 PPC_LL r5,_CCR(r1)
124 mtcr r5
125 REST_GPR(0,r1)
126 REST_30GPRS(r1)
127 /* Restore the previous SP */
128 addi r1,r1,INT_FRAME_SIZE
129
130 .global optprobe_template_ret
131 optprobe_template_ret:
132 /* ... and jump back from trampoline *
133 nop
134
135 .global optprobe_template_end
136 optprobe_template_end:
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