1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * etrap.S: Preparing for entry into the kernel on Sparc V9.
4 *
5 * Copyright (C) 1996, 1997 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
7 */
8
9
10#include <asm/asi.h>
11#include <asm/pstate.h>
12#include <asm/ptrace.h>
13#include <asm/page.h>
14#include <asm/spitfire.h>
15#include <asm/head.h>
16#include <asm/processor.h>
17#include <asm/mmu.h>
18
19#define TASK_REGOFF (THREAD_SIZE-TRACEREG_SZ-STACKFRAME_SZ)
20#define ETRAP_PSTATE1 (PSTATE_TSO | PSTATE_PRIV)
21#define ETRAP_PSTATE2 \
22 (PSTATE_TSO | PSTATE_PEF | PSTATE_PRIV | PSTATE_IE)
23
24/*
25 * On entry, %g7 is return address - 0x4.
26 * %g4 and %g5 will be preserved %l4 and %l5 respectively.
27 */
28
29 .text
30 .align 64
31 .globl etrap_syscall, etrap, etrap_irq, etraptl1
32etrap: rdpr %pil, %g2
33etrap_irq: clr %g3
34etrap_syscall: TRAP_LOAD_THREAD_REG(%g6, %g1)
35 rdpr %tstate, %g1
36 or %g1, %g3, %g1
37 sllx %g2, 20, %g3
38 andcc %g1, TSTATE_PRIV, %g0
39 or %g1, %g3, %g1
40 bne,pn %xcc, 1f
41 sub %sp, STACKFRAME_SZ+TRACEREG_SZ-STACK_BIAS, %g2
42661: wrpr %g0, 7, %cleanwin
43 .section .fast_win_ctrl_1insn_patch, "ax"
44 .word 661b
45 .word 0x85880000 ! allclean
46 .previous
47
48 sethi %hi(TASK_REGOFF), %g2
49 sethi %hi(TSTATE_PEF), %g3
50 or %g2, %lo(TASK_REGOFF), %g2
51 and %g1, %g3, %g3
52 brnz,pn %g3, 1f
53 add %g6, %g2, %g2
54 wr %g0, 0, %fprs
551: rdpr %tpc, %g3
56
57 stx %g1, [%g2 + STACKFRAME_SZ + PT_V9_TSTATE]
58 rdpr %tnpc, %g1
59 stx %g3, [%g2 + STACKFRAME_SZ + PT_V9_TPC]
60 rd %y, %g3
61 stx %g1, [%g2 + STACKFRAME_SZ + PT_V9_TNPC]
62 rdpr %tt, %g1
63 st %g3, [%g2 + STACKFRAME_SZ + PT_V9_Y]
64 sethi %hi(PT_REGS_MAGIC), %g3
65 or %g3, %g1, %g1
66 st %g1, [%g2 + STACKFRAME_SZ + PT_V9_MAGIC]
67
68 rdpr %cansave, %g1
69 brnz,pt %g1, etrap_save
70 nop
71
72 rdpr %cwp, %g1
73 add %g1, 2, %g1
74 wrpr %g1, %cwp
75 be,pt %xcc, etrap_user_spill
76 mov ASI_AIUP, %g3
77
78 rdpr %otherwin, %g3
79 brz %g3, etrap_kernel_spill
80 mov ASI_AIUS, %g3
81
82etrap_user_spill:
83
84 wr %g3, 0x0, %asi
85 ldx [%g6 + TI_FLAGS], %g3
86 and %g3, _TIF_32BIT, %g3
87 brnz,pt %g3, etrap_user_spill_32bit
88 nop
89 ba,a,pt %xcc, etrap_user_spill_64bit
90
91etrap_save: save %g2, -STACK_BIAS, %sp
92 mov %g6, %l6
93
94 bne,pn %xcc, 3f
95 mov PRIMARY_CONTEXT, %l4
96661: rdpr %canrestore, %g3
97 .section .fast_win_ctrl_1insn_patch, "ax"
98 .word 661b
99 nop
100 .previous
101
102 rdpr %wstate, %g2
103661: wrpr %g0, 0, %canrestore
104 .section .fast_win_ctrl_1insn_patch, "ax"
105 .word 661b
106 nop
107 .previous
108 sll %g2, 3, %g2
109
110 /* Set TI_SYS_FPDEPTH to 1 and clear TI_SYS_NOERROR. */
111 mov 1, %l5
112 sth %l5, [%l6 + TI_SYS_NOERROR]
113
114661: wrpr %g3, 0, %otherwin
115 .section .fast_win_ctrl_1insn_patch, "ax"
116 .word 661b
117 .word 0x87880000 ! otherw
118 .previous
119
120 wrpr %g2, 0, %wstate
121 sethi %hi(sparc64_kern_pri_context), %g2
122 ldx [%g2 + %lo(sparc64_kern_pri_context)], %g3
123
124661: stxa %g3, [%l4] ASI_DMMU
125 .section .sun4v_1insn_patch, "ax"
126 .word 661b
127 stxa %g3, [%l4] ASI_MMU
128 .previous
129
130 sethi %hi(KERNBASE), %l4
131 flush %l4
132 mov ASI_AIUS, %l7
1332: mov %g4, %l4
134 mov %g5, %l5
135 add %g7, 4, %l2
136
137 /* Go to trap time globals so we can save them. */
138661: wrpr %g0, ETRAP_PSTATE1, %pstate
139 .section .sun4v_1insn_patch, "ax"
140 .word 661b
141 SET_GL(0)
142 .previous
143
144 stx %g1, [%sp + PTREGS_OFF + PT_V9_G1]
145 stx %g2, [%sp + PTREGS_OFF + PT_V9_G2]
146 sllx %l7, 24, %l7
147 stx %g3, [%sp + PTREGS_OFF + PT_V9_G3]
148 rdpr %cwp, %l0
149 stx %g4, [%sp + PTREGS_OFF + PT_V9_G4]
150 stx %g5, [%sp + PTREGS_OFF + PT_V9_G5]
151 stx %g6, [%sp + PTREGS_OFF + PT_V9_G6]
152 stx %g7, [%sp + PTREGS_OFF + PT_V9_G7]
153 or %l7, %l0, %l7
154661: sethi %hi(TSTATE_TSO | TSTATE_PEF), %l0
155 /* If userspace is using ADI, it could potentially pass
156 * a pointer with version tag embedded in it. To maintain
157 * the ADI security, we must enable PSTATE.mcde. Userspace
158 * would have already set TTE.mcd in an earlier call to
159 * kernel and set the version tag for the address being
160 * dereferenced. Setting PSTATE.mcde would ensure any
161 * access to userspace data through a system call honors
162 * ADI and does not allow a rogue app to bypass ADI by
163 * using system calls. Setting PSTATE.mcde only affects
164 * accesses to virtual addresses that have TTE.mcd set.
165 * Set PMCDPER to ensure any exceptions caused by ADI
166 * version tag mismatch are exposed before system call
167 * returns to userspace. Setting PMCDPER affects only
168 * writes to virtual addresses that have TTE.mcd set and
169 * have a version tag set as well.
170 */
171 .section .sun_m7_1insn_patch, "ax"
172 .word 661b
173 sethi %hi(TSTATE_TSO | TSTATE_PEF | TSTATE_MCDE), %l0
174 .previous
175661: nop
176 .section .sun_m7_1insn_patch, "ax"
177 .word 661b
178 .word 0xaf902001 /* wrpr %g0, 1, %pmcdper */
179 .previous
180 or %l7, %l0, %l7
181 wrpr %l2, %tnpc
182 wrpr %l7, (TSTATE_PRIV | TSTATE_IE), %tstate
183 stx %i0, [%sp + PTREGS_OFF + PT_V9_I0]
184 stx %i1, [%sp + PTREGS_OFF + PT_V9_I1]
185 stx %i2, [%sp + PTREGS_OFF + PT_V9_I2]
186 stx %i3, [%sp + PTREGS_OFF + PT_V9_I3]
187 stx %i4, [%sp + PTREGS_OFF + PT_V9_I4]
188 stx %i5, [%sp + PTREGS_OFF + PT_V9_I5]
189 stx %i6, [%sp + PTREGS_OFF + PT_V9_I6]
190 mov %l6, %g6
191 stx %i7, [%sp + PTREGS_OFF + PT_V9_I7]
192 LOAD_PER_CPU_BASE(%g5, %g6, %g4, %g3, %l1)
193 ldx [%g6 + TI_TASK], %g4
194 done
195
1963: mov ASI_P, %l7
197 ldub [%l6 + TI_FPDEPTH], %l5
198 add %l6, TI_FPSAVED + 1, %l4
199 srl %l5, 1, %l3
200 add %l5, 2, %l5
201
202 /* Set TI_SYS_FPDEPTH to %l5 and clear TI_SYS_NOERROR. */
203 sth %l5, [%l6 + TI_SYS_NOERROR]
204 ba,pt %xcc, 2b
205 stb %g0, [%l4 + %l3]
206 nop
207
208etraptl1: /* Save tstate/tpc/tnpc of TL 1-->4 and the tl register itself.
209 * We place this right after pt_regs on the trap stack.
210 * The layout is:
211 * 0x00 TL1's TSTATE
212 * 0x08 TL1's TPC
213 * 0x10 TL1's TNPC
214 * 0x18 TL1's TT
215 * ...
216 * 0x58 TL4's TT
217 * 0x60 TL
218 */
219 TRAP_LOAD_THREAD_REG(%g6, %g1)
220 sub %sp, ((4 * 8) * 4) + 8, %g2
221 rdpr %tl, %g1
222
223 wrpr %g0, 1, %tl
224 rdpr %tstate, %g3
225 stx %g3, [%g2 + STACK_BIAS + 0x00]
226 rdpr %tpc, %g3
227 stx %g3, [%g2 + STACK_BIAS + 0x08]
228 rdpr %tnpc, %g3
229 stx %g3, [%g2 + STACK_BIAS + 0x10]
230 rdpr %tt, %g3
231 stx %g3, [%g2 + STACK_BIAS + 0x18]
232
233 wrpr %g0, 2, %tl
234 rdpr %tstate, %g3
235 stx %g3, [%g2 + STACK_BIAS + 0x20]
236 rdpr %tpc, %g3
237 stx %g3, [%g2 + STACK_BIAS + 0x28]
238 rdpr %tnpc, %g3
239 stx %g3, [%g2 + STACK_BIAS + 0x30]
240 rdpr %tt, %g3
241 stx %g3, [%g2 + STACK_BIAS + 0x38]
242
243 sethi %hi(is_sun4v), %g3
244 lduw [%g3 + %lo(is_sun4v)], %g3
245 brnz,pn %g3, finish_tl1_capture
246 nop
247
248 wrpr %g0, 3, %tl
249 rdpr %tstate, %g3
250 stx %g3, [%g2 + STACK_BIAS + 0x40]
251 rdpr %tpc, %g3
252 stx %g3, [%g2 + STACK_BIAS + 0x48]
253 rdpr %tnpc, %g3
254 stx %g3, [%g2 + STACK_BIAS + 0x50]
255 rdpr %tt, %g3
256 stx %g3, [%g2 + STACK_BIAS + 0x58]
257
258 wrpr %g0, 4, %tl
259 rdpr %tstate, %g3
260 stx %g3, [%g2 + STACK_BIAS + 0x60]
261 rdpr %tpc, %g3
262 stx %g3, [%g2 + STACK_BIAS + 0x68]
263 rdpr %tnpc, %g3
264 stx %g3, [%g2 + STACK_BIAS + 0x70]
265 rdpr %tt, %g3
266 stx %g3, [%g2 + STACK_BIAS + 0x78]
267
268 stx %g1, [%g2 + STACK_BIAS + 0x80]
269
270finish_tl1_capture:
271 wrpr %g0, 1, %tl
272661: nop
273 .section .sun4v_1insn_patch, "ax"
274 .word 661b
275 SET_GL(1)
276 .previous
277
278 rdpr %tstate, %g1
279 sub %g2, STACKFRAME_SZ + TRACEREG_SZ - STACK_BIAS, %g2
280 ba,pt %xcc, 1b
281 andcc %g1, TSTATE_PRIV, %g0
282
283#undef TASK_REGOFF
284#undef ETRAP_PSTATE1
285

source code of linux/arch/sparc/kernel/etrap_64.S