1 /* SPDX-License-Identifier: GPL-2.0-only */ !! 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* 2 /*
3 * Common Low Level Interrupts/Traps/Exception !! 3 * arch/alpha/kernel/entry.S
4 * (included from entry-<isa>.S <<
5 * 4 *
6 * Copyright (C) 2014-15 Synopsys, Inc. (www.s !! 5 * Kernel entry-points.
7 * Copyright (C) 2004, 2007-2010, 2011-2012 Sy <<
8 */ 6 */
9 7
10 /*-------------------------------------------- !! 8 #include <asm/asm-offsets.h>
11 * Function ABI !! 9 #include <asm/thread_info.h>
12 *-------------------------------------------- !! 10 #include <asm/pal.h>
>> 11 #include <asm/errno.h>
>> 12 #include <asm/unistd.h>
>> 13
>> 14 .text
>> 15 .set noat
>> 16 .cfi_sections .debug_frame
>> 17
>> 18 /* Stack offsets. */
>> 19 #define SP_OFF 184
>> 20 #define SWITCH_STACK_SIZE 320
>> 21
>> 22 .macro CFI_START_OSF_FRAME func
>> 23 .align 4
>> 24 .globl \func
>> 25 .type \func,@function
>> 26 \func:
>> 27 .cfi_startproc simple
>> 28 .cfi_return_column 64
>> 29 .cfi_def_cfa $sp, 48
>> 30 .cfi_rel_offset 64, 8
>> 31 .cfi_rel_offset $gp, 16
>> 32 .cfi_rel_offset $16, 24
>> 33 .cfi_rel_offset $17, 32
>> 34 .cfi_rel_offset $18, 40
>> 35 .endm
>> 36
>> 37 .macro CFI_END_OSF_FRAME func
>> 38 .cfi_endproc
>> 39 .size \func, . - \func
>> 40 .endm
>> 41
>> 42 /*
>> 43 * This defines the normal kernel pt-regs layout.
13 * 44 *
14 * Arguments r0 - r !! 45 * regs 9-15 preserved by C code
15 * Caller Saved Registers r0 - r !! 46 * regs 16-18 saved by PAL-code
16 * Callee Saved Registers r13- r !! 47 * regs 29-30 saved and set up by PAL-code
17 * Global Pointer (gp) r26 !! 48 * JRP - Save regs 16-18 in a special area of the stack, so that
18 * Frame Pointer (fp) r27 !! 49 * the palcode-provided values are available to the signal handler.
19 * Stack Pointer (sp) r28 <<
20 * Branch link register (blink) r31 <<
21 *-------------------------------------------- <<
22 */ 50 */
23 51
24 ;################### Special Sys Call Wrappers !! 52 .macro SAVE_ALL
25 !! 53 subq $sp, SP_OFF, $sp
26 ENTRY(sys_clone_wrapper) !! 54 .cfi_adjust_cfa_offset SP_OFF
27 SAVE_CALLEE_SAVED_USER !! 55 stq $0, 0($sp)
28 bl @sys_clone !! 56 stq $1, 8($sp)
29 DISCARD_CALLEE_SAVED_USER !! 57 stq $2, 16($sp)
30 !! 58 stq $3, 24($sp)
31 GET_CURR_THR_INFO_FLAGS r10 !! 59 stq $4, 32($sp)
32 and.f 0, r10, _TIF_SYSCALL_WORK !! 60 stq $28, 144($sp)
33 bnz tracesys_exit !! 61 .cfi_rel_offset $0, 0
34 !! 62 .cfi_rel_offset $1, 8
35 b .Lret_from_system_call !! 63 .cfi_rel_offset $2, 16
36 END(sys_clone_wrapper) !! 64 .cfi_rel_offset $3, 24
37 !! 65 .cfi_rel_offset $4, 32
38 ENTRY(sys_clone3_wrapper) !! 66 .cfi_rel_offset $28, 144
39 SAVE_CALLEE_SAVED_USER !! 67 lda $2, alpha_mv
40 bl @sys_clone3 !! 68 stq $5, 40($sp)
41 DISCARD_CALLEE_SAVED_USER !! 69 stq $6, 48($sp)
42 !! 70 stq $7, 56($sp)
43 GET_CURR_THR_INFO_FLAGS r10 !! 71 stq $8, 64($sp)
44 and.f 0, r10, _TIF_SYSCALL_WORK !! 72 stq $19, 72($sp)
45 bnz tracesys_exit !! 73 stq $20, 80($sp)
46 !! 74 stq $21, 88($sp)
47 b .Lret_from_system_call !! 75 ldq $2, HAE_CACHE($2)
48 END(sys_clone3_wrapper) !! 76 stq $22, 96($sp)
49 !! 77 stq $23, 104($sp)
50 ENTRY(ret_from_fork) !! 78 stq $24, 112($sp)
51 ; when the forked child comes here fro !! 79 stq $25, 120($sp)
52 ; r0 has the last task pointer. !! 80 stq $26, 128($sp)
53 ; put last task in scheduler queue !! 81 stq $27, 136($sp)
54 jl @schedule_tail !! 82 stq $2, 152($sp)
55 !! 83 stq $16, 160($sp)
56 ld r9, [sp, PT_status32] !! 84 stq $17, 168($sp)
57 brne r9, 0, 1f !! 85 stq $18, 176($sp)
58 !! 86 .cfi_rel_offset $5, 40
59 jl.d [r14] ; kernel threa !! 87 .cfi_rel_offset $6, 48
60 mov r0, r13 ; (see PF_KTHR !! 88 .cfi_rel_offset $7, 56
61 !! 89 .cfi_rel_offset $8, 64
62 1: !! 90 .cfi_rel_offset $19, 72
63 ; Return to user space !! 91 .cfi_rel_offset $20, 80
64 ; 1. Any forked task (Reach here via B !! 92 .cfi_rel_offset $21, 88
65 ; 2. First ever init task (Reach here !! 93 .cfi_rel_offset $22, 96
66 ; This is the historic "kernel_exec !! 94 .cfi_rel_offset $23, 104
67 ; user mode, in a round about way s !! 95 .cfi_rel_offset $24, 112
68 ; a kernel thread which is executed !! 96 .cfi_rel_offset $25, 120
69 ; out whenever kernel_execve (now i !! 97 .cfi_rel_offset $26, 128
70 b ret_from_exception !! 98 .cfi_rel_offset $27, 136
71 END(ret_from_fork) !! 99 .endm
72 !! 100
73 ;################### Non TLB Exception Handlin !! 101 .macro RESTORE_ALL
74 !! 102 lda $19, alpha_mv
75 ; -------------------------------------------- !! 103 ldq $0, 0($sp)
76 ; Instruction Error Exception Handler !! 104 ldq $1, 8($sp)
77 ; -------------------------------------------- !! 105 ldq $2, 16($sp)
78 !! 106 ldq $3, 24($sp)
79 ENTRY(instr_service) !! 107 ldq $21, 152($sp)
80 !! 108 ldq $20, HAE_CACHE($19)
81 EXCEPTION_PROLOGUE !! 109 ldq $4, 32($sp)
82 !! 110 ldq $5, 40($sp)
83 bl do_insterror_or_kprobe !! 111 ldq $6, 48($sp)
84 b ret_from_exception !! 112 ldq $7, 56($sp)
85 END(instr_service) !! 113 subq $20, $21, $20
86 !! 114 ldq $8, 64($sp)
87 ; -------------------------------------------- !! 115 beq $20, 99f
88 ; Machine Check Exception Handler !! 116 ldq $20, HAE_REG($19)
89 ; -------------------------------------------- !! 117 stq $21, HAE_CACHE($19)
90 !! 118 stq $21, 0($20)
91 ENTRY(EV_MachineCheck) !! 119 99: ldq $19, 72($sp)
92 !! 120 ldq $20, 80($sp)
93 EXCEPTION_PROLOGUE_KEEP_AE ; ECR !! 121 ldq $21, 88($sp)
94 !! 122 ldq $22, 96($sp)
95 lr r0, [efa] !! 123 ldq $23, 104($sp)
96 mov r1, sp !! 124 ldq $24, 112($sp)
97 !! 125 ldq $25, 120($sp)
98 ; MC exceptions disable MMU !! 126 ldq $26, 128($sp)
99 ARC_MMU_REENABLE r3 !! 127 ldq $27, 136($sp)
100 !! 128 ldq $28, 144($sp)
101 lsr r3, r10, 8 !! 129 addq $sp, SP_OFF, $sp
102 bmsk r3, r3, 7 !! 130 .cfi_restore $0
103 brne r3, ECR_C_MCHK_DUP_TLB, 1f !! 131 .cfi_restore $1
104 !! 132 .cfi_restore $2
105 bl do_tlb_overlap_fault !! 133 .cfi_restore $3
106 b ret_from_exception !! 134 .cfi_restore $4
107 !! 135 .cfi_restore $5
108 1: !! 136 .cfi_restore $6
109 ; DEAD END: can't do much, display Reg !! 137 .cfi_restore $7
110 SAVE_CALLEE_SAVED_USER !! 138 .cfi_restore $8
111 !! 139 .cfi_restore $19
112 GET_CURR_TASK_FIELD_PTR TASK_THREAD, !! 140 .cfi_restore $20
113 st sp, [r10, THREAD_CALLEE_REG] !! 141 .cfi_restore $21
114 !! 142 .cfi_restore $22
115 j do_machine_check_fault !! 143 .cfi_restore $23
116 !! 144 .cfi_restore $24
117 END(EV_MachineCheck) !! 145 .cfi_restore $25
118 !! 146 .cfi_restore $26
119 ; -------------------------------------------- !! 147 .cfi_restore $27
120 ; Privilege Violation Exception Handler !! 148 .cfi_restore $28
121 ; -------------------------------------------- !! 149 .cfi_adjust_cfa_offset -SP_OFF
122 ENTRY(EV_PrivilegeV) !! 150 .endm
123 !! 151
124 EXCEPTION_PROLOGUE !! 152 .macro DO_SWITCH_STACK
125 !! 153 bsr $1, do_switch_stack
126 bl do_privilege_fault !! 154 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
127 b ret_from_exception !! 155 .cfi_rel_offset $9, 0
128 END(EV_PrivilegeV) !! 156 .cfi_rel_offset $10, 8
129 !! 157 .cfi_rel_offset $11, 16
130 ; -------------------------------------------- !! 158 .cfi_rel_offset $12, 24
131 ; Extension Instruction Exception Handler !! 159 .cfi_rel_offset $13, 32
132 ; -------------------------------------------- !! 160 .cfi_rel_offset $14, 40
133 ENTRY(EV_Extension) !! 161 .cfi_rel_offset $15, 48
134 !! 162 /* We don't really care about the FP registers for debugging. */
135 EXCEPTION_PROLOGUE !! 163 .endm
136 !! 164
137 bl do_extension_fault !! 165 .macro UNDO_SWITCH_STACK
138 b ret_from_exception !! 166 bsr $1, undo_switch_stack
139 END(EV_Extension) !! 167 .cfi_restore $9
140 !! 168 .cfi_restore $10
141 ;################ Trap Handling (Syscall, Brea !! 169 .cfi_restore $11
142 !! 170 .cfi_restore $12
143 ; -------------------------------------------- !! 171 .cfi_restore $13
144 ; syscall Tracing !! 172 .cfi_restore $14
145 ; -------------------------------------------- !! 173 .cfi_restore $15
146 tracesys: !! 174 .cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
147 ; safekeep EFA (r12) if syscall tracer !! 175 .endm
148 ; for traps, ERET is pre-commit so poi <<
149 GET_CURR_TASK_FIELD_PTR TASK_THREAD, <<
150 st r12, [r11, THREAD_FAULT_ADDR] <<
151 <<
152 ; PRE syscall trace hook <<
153 mov r0, sp <<
154 bl @syscall_trace_enter <<
155 <<
156 ; Tracing code now returns the syscall <<
157 mov r8, r0 <<
158 <<
159 ; Do the Sys Call as we normally would <<
160 cmp r8, NR_syscalls - 1 <<
161 mov.hi r0, -ENOSYS <<
162 bhi tracesys_exit <<
163 <<
164 ; Restore the sys-call args. Mere invo <<
165 ; clobbered them (since they are in sc <<
166 ; have deliberately changed the syscal <<
167 ld r0, [sp, PT_r0] <<
168 ld r1, [sp, PT_r1] <<
169 ld r2, [sp, PT_r2] <<
170 ld r3, [sp, PT_r3] <<
171 ld r4, [sp, PT_r4] <<
172 ld r5, [sp, PT_r5] <<
173 ld r6, [sp, PT_r6] <<
174 ld r7, [sp, PT_r7] <<
175 ld.as r9, [sys_call_table, r8] <<
176 jl [r9] <<
177 <<
178 tracesys_exit: <<
179 st r0, [sp, PT_r0] <<
180 <<
181 ; POST syscall trace hook <<
182 mov r0, sp ; pt_regs need <<
183 bl @syscall_trace_exit <<
184 <<
185 ; don't call ret_from_system_call as i <<
186 b ret_from_exception <<
187 <<
188 ; -------------------------------------------- <<
189 ; Breakpoint TRAP <<
190 ; -------------------------------------------- <<
191 trap_with_param: <<
192 mov r0, r12 ; EFA in case ptracer/ <<
193 mov r1, sp ; pt_regs <<
194 <<
195 ; save callee regs in case tracer/gdb <<
196 SAVE_CALLEE_SAVED_USER <<
197 <<
198 ; safekeep ref to callee regs <<
199 GET_CURR_TASK_FIELD_PTR TASK_THREAD, <<
200 st sp, [r10, THREAD_CALLEE_REG] <<
201 <<
202 ; call the non syscall trap handler <<
203 bl do_non_swi_trap <<
204 <<
205 ; unwind stack to discard callee regs <<
206 DISCARD_CALLEE_SAVED_USER <<
207 <<
208 b ret_from_exception <<
209 176
210 ; -------------------------------------------- !! 177 /*
211 ; syscall TRAP !! 178 * Non-syscall kernel entry points.
212 ; ABI: (r0-r7) up to 8 args, (r8) syscall numb !! 179 */
213 ; -------------------------------------------- <<
214 <<
215 ENTRY(EV_Trap) <<
216 <<
217 EXCEPTION_PROLOGUE_KEEP_AE <<
218 <<
219 lr r12, [efa] <<
220 <<
221 FAKE_RET_FROM_EXCPN <<
222 <<
223 ;============ TRAP N : breakpoints, kp <<
224 bmsk.f 0, r10, 7 <<
225 bnz trap_with_param <<
226 <<
227 ;============ TRAP 0 (no param): sysca <<
228 <<
229 ; syscall tracing ongoing, invoke pre- <<
230 GET_CURR_THR_INFO_FLAGS r10 <<
231 and.f 0, r10, _TIF_SYSCALL_WORK <<
232 bnz tracesys ; this never comes bac <<
233 <<
234 ;============ Normal syscall case <<
235 <<
236 cmp r8, NR_syscalls - 1 <<
237 mov.hi r0, -ENOSYS <<
238 bhi .Lret_from_system_call <<
239 <<
240 ld.as r9,[sys_call_table, r8] <<
241 jl [r9] <<
242 <<
243 .Lret_from_system_call: <<
244 st r0, [sp, PT_r0] ; sys call ret <<
245 <<
246 ; fall through to ret_from_exception <<
247 END(EV_Trap) <<
248 <<
249 ;############# Return from Intr/Excp/Trap (Lin <<
250 ; <<
251 ; If ret to user mode do we need to handle sig <<
252 <<
253 ENTRY(ret_from_exception) <<
254 <<
255 ; Pre-{IRQ,Trap,Exception} K/U mode fr <<
256 ld r8, [sp, PT_status32] ; returnin <<
257 <<
258 bbit0 r8, STATUS_U_BIT, resume_kernel <<
259 <<
260 ; Before returning to User mode check- <<
261 ; such as rescheduling/signal-delivery <<
262 resume_user_mode_begin: <<
263 <<
264 ; Disable IRQs to ensures that chk for <<
265 ; (and we don't end up missing a NEED_ <<
266 ; interim IRQ). <<
267 IRQ_DISABLE r10 <<
268 <<
269 ; Fast Path return to user mode if no <<
270 GET_CURR_THR_INFO_FLAGS r9 <<
271 and.f 0, r9, _TIF_WORK_MASK <<
272 bz .Lrestore_regs <<
273 <<
274 ; --- (Slow Path #1) task preemption - <<
275 bbit0 r9, TIF_NEED_RESCHED, .Lchk_pen <<
276 mov blink, resume_user_mode_begin <<
277 j @schedule ; BTST+Bnz cau <<
278 <<
279 .Lchk_pend_signals: <<
280 IRQ_ENABLE r10 <<
281 <<
282 ; --- (Slow Path #2) pending signal - <<
283 mov r0, sp ; pt_regs for arg to d <<
284 <<
285 GET_CURR_THR_INFO_FLAGS r9 <<
286 and.f 0, r9, _TIF_SIGPENDING|_TIF_NO <<
287 bz .Lchk_notify_resume <<
288 <<
289 ; Normal Trap/IRQ entry only saves Scr <<
290 ; in pt_reg since the "C" ABI (kernel <<
291 ; save/restore callee-saved regs. <<
292 ; <<
293 ; However, here we need to explicitly <<
294 ; (i) If this signal causes coredump <<
295 ; (ii) If signal is SIGTRAP/SIGSTOP, t <<
296 ; tracer might call PEEKUSR(CALLE <<
297 ; <<
298 ; NOTE: SP will grow up by size of CAL <<
299 SAVE_CALLEE_SAVED_USER <<
300 <<
301 ; save location of saved Callee Regs @ <<
302 GET_CURR_TASK_FIELD_PTR TASK_THREAD, <<
303 st sp, [r10, THREAD_CALLEE_REG] <<
304 <<
305 bl @do_signal <<
306 180
307 ; Ideally we want to discard the Calle !! 181 CFI_START_OSF_FRAME entInt
308 ; a tracing signal, tracer could have !! 182 SAVE_ALL
309 RESTORE_CALLEE_SAVED_USER !! 183 lda $8, 0x3fff
>> 184 lda $26, ret_from_sys_call
>> 185 bic $sp, $8, $8
>> 186 mov $sp, $19
>> 187 jsr $31, do_entInt
>> 188 CFI_END_OSF_FRAME entInt
>> 189
>> 190 CFI_START_OSF_FRAME entArith
>> 191 SAVE_ALL
>> 192 lda $8, 0x3fff
>> 193 lda $26, ret_from_sys_call
>> 194 bic $sp, $8, $8
>> 195 mov $sp, $18
>> 196 jsr $31, do_entArith
>> 197 CFI_END_OSF_FRAME entArith
>> 198
>> 199 CFI_START_OSF_FRAME entMM
>> 200 SAVE_ALL
>> 201 /* save $9 - $15 so the inline exception code can manipulate them. */
>> 202 subq $sp, 56, $sp
>> 203 .cfi_adjust_cfa_offset 56
>> 204 stq $9, 0($sp)
>> 205 stq $10, 8($sp)
>> 206 stq $11, 16($sp)
>> 207 stq $12, 24($sp)
>> 208 stq $13, 32($sp)
>> 209 stq $14, 40($sp)
>> 210 stq $15, 48($sp)
>> 211 .cfi_rel_offset $9, 0
>> 212 .cfi_rel_offset $10, 8
>> 213 .cfi_rel_offset $11, 16
>> 214 .cfi_rel_offset $12, 24
>> 215 .cfi_rel_offset $13, 32
>> 216 .cfi_rel_offset $14, 40
>> 217 .cfi_rel_offset $15, 48
>> 218 addq $sp, 56, $19
>> 219 /* handle the fault */
>> 220 lda $8, 0x3fff
>> 221 bic $sp, $8, $8
>> 222 jsr $26, do_page_fault
>> 223 /* reload the registers after the exception code played. */
>> 224 ldq $9, 0($sp)
>> 225 ldq $10, 8($sp)
>> 226 ldq $11, 16($sp)
>> 227 ldq $12, 24($sp)
>> 228 ldq $13, 32($sp)
>> 229 ldq $14, 40($sp)
>> 230 ldq $15, 48($sp)
>> 231 addq $sp, 56, $sp
>> 232 .cfi_restore $9
>> 233 .cfi_restore $10
>> 234 .cfi_restore $11
>> 235 .cfi_restore $12
>> 236 .cfi_restore $13
>> 237 .cfi_restore $14
>> 238 .cfi_restore $15
>> 239 .cfi_adjust_cfa_offset -56
>> 240 /* finish up the syscall as normal. */
>> 241 br ret_from_sys_call
>> 242 CFI_END_OSF_FRAME entMM
>> 243
>> 244 CFI_START_OSF_FRAME entIF
>> 245 SAVE_ALL
>> 246 lda $8, 0x3fff
>> 247 lda $26, ret_from_sys_call
>> 248 bic $sp, $8, $8
>> 249 mov $sp, $17
>> 250 jsr $31, do_entIF
>> 251 CFI_END_OSF_FRAME entIF
>> 252
>> 253 CFI_START_OSF_FRAME entUna
>> 254 lda $sp, -256($sp)
>> 255 .cfi_adjust_cfa_offset 256
>> 256 stq $0, 0($sp)
>> 257 .cfi_rel_offset $0, 0
>> 258 .cfi_remember_state
>> 259 ldq $0, 256($sp) /* get PS */
>> 260 stq $1, 8($sp)
>> 261 stq $2, 16($sp)
>> 262 stq $3, 24($sp)
>> 263 and $0, 8, $0 /* user mode? */
>> 264 stq $4, 32($sp)
>> 265 bne $0, entUnaUser /* yup -> do user-level unaligned fault */
>> 266 stq $5, 40($sp)
>> 267 stq $6, 48($sp)
>> 268 stq $7, 56($sp)
>> 269 stq $8, 64($sp)
>> 270 stq $9, 72($sp)
>> 271 stq $10, 80($sp)
>> 272 stq $11, 88($sp)
>> 273 stq $12, 96($sp)
>> 274 stq $13, 104($sp)
>> 275 stq $14, 112($sp)
>> 276 stq $15, 120($sp)
>> 277 /* 16-18 PAL-saved */
>> 278 stq $19, 152($sp)
>> 279 stq $20, 160($sp)
>> 280 stq $21, 168($sp)
>> 281 stq $22, 176($sp)
>> 282 stq $23, 184($sp)
>> 283 stq $24, 192($sp)
>> 284 stq $25, 200($sp)
>> 285 stq $26, 208($sp)
>> 286 stq $27, 216($sp)
>> 287 stq $28, 224($sp)
>> 288 mov $sp, $19
>> 289 stq $gp, 232($sp)
>> 290 .cfi_rel_offset $1, 1*8
>> 291 .cfi_rel_offset $2, 2*8
>> 292 .cfi_rel_offset $3, 3*8
>> 293 .cfi_rel_offset $4, 4*8
>> 294 .cfi_rel_offset $5, 5*8
>> 295 .cfi_rel_offset $6, 6*8
>> 296 .cfi_rel_offset $7, 7*8
>> 297 .cfi_rel_offset $8, 8*8
>> 298 .cfi_rel_offset $9, 9*8
>> 299 .cfi_rel_offset $10, 10*8
>> 300 .cfi_rel_offset $11, 11*8
>> 301 .cfi_rel_offset $12, 12*8
>> 302 .cfi_rel_offset $13, 13*8
>> 303 .cfi_rel_offset $14, 14*8
>> 304 .cfi_rel_offset $15, 15*8
>> 305 .cfi_rel_offset $19, 19*8
>> 306 .cfi_rel_offset $20, 20*8
>> 307 .cfi_rel_offset $21, 21*8
>> 308 .cfi_rel_offset $22, 22*8
>> 309 .cfi_rel_offset $23, 23*8
>> 310 .cfi_rel_offset $24, 24*8
>> 311 .cfi_rel_offset $25, 25*8
>> 312 .cfi_rel_offset $26, 26*8
>> 313 .cfi_rel_offset $27, 27*8
>> 314 .cfi_rel_offset $28, 28*8
>> 315 .cfi_rel_offset $29, 29*8
>> 316 lda $8, 0x3fff
>> 317 stq $31, 248($sp)
>> 318 bic $sp, $8, $8
>> 319 jsr $26, do_entUna
>> 320 ldq $0, 0($sp)
>> 321 ldq $1, 8($sp)
>> 322 ldq $2, 16($sp)
>> 323 ldq $3, 24($sp)
>> 324 ldq $4, 32($sp)
>> 325 ldq $5, 40($sp)
>> 326 ldq $6, 48($sp)
>> 327 ldq $7, 56($sp)
>> 328 ldq $8, 64($sp)
>> 329 ldq $9, 72($sp)
>> 330 ldq $10, 80($sp)
>> 331 ldq $11, 88($sp)
>> 332 ldq $12, 96($sp)
>> 333 ldq $13, 104($sp)
>> 334 ldq $14, 112($sp)
>> 335 ldq $15, 120($sp)
>> 336 /* 16-18 PAL-saved */
>> 337 ldq $19, 152($sp)
>> 338 ldq $20, 160($sp)
>> 339 ldq $21, 168($sp)
>> 340 ldq $22, 176($sp)
>> 341 ldq $23, 184($sp)
>> 342 ldq $24, 192($sp)
>> 343 ldq $25, 200($sp)
>> 344 ldq $26, 208($sp)
>> 345 ldq $27, 216($sp)
>> 346 ldq $28, 224($sp)
>> 347 ldq $gp, 232($sp)
>> 348 lda $sp, 256($sp)
>> 349 .cfi_restore $1
>> 350 .cfi_restore $2
>> 351 .cfi_restore $3
>> 352 .cfi_restore $4
>> 353 .cfi_restore $5
>> 354 .cfi_restore $6
>> 355 .cfi_restore $7
>> 356 .cfi_restore $8
>> 357 .cfi_restore $9
>> 358 .cfi_restore $10
>> 359 .cfi_restore $11
>> 360 .cfi_restore $12
>> 361 .cfi_restore $13
>> 362 .cfi_restore $14
>> 363 .cfi_restore $15
>> 364 .cfi_restore $19
>> 365 .cfi_restore $20
>> 366 .cfi_restore $21
>> 367 .cfi_restore $22
>> 368 .cfi_restore $23
>> 369 .cfi_restore $24
>> 370 .cfi_restore $25
>> 371 .cfi_restore $26
>> 372 .cfi_restore $27
>> 373 .cfi_restore $28
>> 374 .cfi_restore $29
>> 375 .cfi_adjust_cfa_offset -256
>> 376 call_pal PAL_rti
>> 377
>> 378 .align 4
>> 379 entUnaUser:
>> 380 .cfi_restore_state
>> 381 ldq $0, 0($sp) /* restore original $0 */
>> 382 lda $sp, 256($sp) /* pop entUna's stack frame */
>> 383 .cfi_restore $0
>> 384 .cfi_adjust_cfa_offset -256
>> 385 SAVE_ALL /* setup normal kernel stack */
>> 386 lda $sp, -56($sp)
>> 387 .cfi_adjust_cfa_offset 56
>> 388 stq $9, 0($sp)
>> 389 stq $10, 8($sp)
>> 390 stq $11, 16($sp)
>> 391 stq $12, 24($sp)
>> 392 stq $13, 32($sp)
>> 393 stq $14, 40($sp)
>> 394 stq $15, 48($sp)
>> 395 .cfi_rel_offset $9, 0
>> 396 .cfi_rel_offset $10, 8
>> 397 .cfi_rel_offset $11, 16
>> 398 .cfi_rel_offset $12, 24
>> 399 .cfi_rel_offset $13, 32
>> 400 .cfi_rel_offset $14, 40
>> 401 .cfi_rel_offset $15, 48
>> 402 lda $8, 0x3fff
>> 403 addq $sp, 56, $19
>> 404 bic $sp, $8, $8
>> 405 jsr $26, do_entUnaUser
>> 406 ldq $9, 0($sp)
>> 407 ldq $10, 8($sp)
>> 408 ldq $11, 16($sp)
>> 409 ldq $12, 24($sp)
>> 410 ldq $13, 32($sp)
>> 411 ldq $14, 40($sp)
>> 412 ldq $15, 48($sp)
>> 413 lda $sp, 56($sp)
>> 414 .cfi_restore $9
>> 415 .cfi_restore $10
>> 416 .cfi_restore $11
>> 417 .cfi_restore $12
>> 418 .cfi_restore $13
>> 419 .cfi_restore $14
>> 420 .cfi_restore $15
>> 421 .cfi_adjust_cfa_offset -56
>> 422 br ret_from_sys_call
>> 423 CFI_END_OSF_FRAME entUna
>> 424
>> 425 CFI_START_OSF_FRAME entDbg
>> 426 SAVE_ALL
>> 427 lda $8, 0x3fff
>> 428 lda $26, ret_from_sys_call
>> 429 bic $sp, $8, $8
>> 430 mov $sp, $16
>> 431 jsr $31, do_entDbg
>> 432 CFI_END_OSF_FRAME entDbg
>> 433
>> 434 /*
>> 435 * The system call entry point is special. Most importantly, it looks
>> 436 * like a function call to userspace as far as clobbered registers. We
>> 437 * do preserve the argument registers (for syscall restarts) and $26
>> 438 * (for leaf syscall functions).
>> 439 *
>> 440 * So much for theory. We don't take advantage of this yet.
>> 441 *
>> 442 * Note that a0-a2 are not saved by PALcode as with the other entry points.
>> 443 */
310 444
311 b resume_user_mode_begin ; loop !! 445 .align 4
>> 446 .globl entSys
>> 447 .type entSys, @function
>> 448 .cfi_startproc simple
>> 449 .cfi_return_column 64
>> 450 .cfi_def_cfa $sp, 48
>> 451 .cfi_rel_offset 64, 8
>> 452 .cfi_rel_offset $gp, 16
>> 453 entSys:
>> 454 SAVE_ALL
>> 455 lda $8, 0x3fff
>> 456 bic $sp, $8, $8
>> 457 lda $4, NR_SYSCALLS($31)
>> 458 stq $16, SP_OFF+24($sp)
>> 459 lda $5, sys_call_table
>> 460 lda $27, sys_ni_syscall
>> 461 cmpult $0, $4, $4
>> 462 ldl $3, TI_FLAGS($8)
>> 463 stq $17, SP_OFF+32($sp)
>> 464 s8addq $0, $5, $5
>> 465 stq $18, SP_OFF+40($sp)
>> 466 .cfi_rel_offset $16, SP_OFF+24
>> 467 .cfi_rel_offset $17, SP_OFF+32
>> 468 .cfi_rel_offset $18, SP_OFF+40
>> 469 #ifdef CONFIG_AUDITSYSCALL
>> 470 lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
>> 471 and $3, $6, $3
>> 472 #endif
>> 473 bne $3, strace
>> 474 beq $4, 1f
>> 475 ldq $27, 0($5)
>> 476 1: jsr $26, ($27), sys_ni_syscall
>> 477 ldgp $gp, 0($26)
>> 478 blt $0, $syscall_error /* the call failed */
>> 479 stq $0, 0($sp)
>> 480 stq $31, 72($sp) /* a3=0 => no error */
>> 481
>> 482 .align 4
>> 483 .globl ret_from_sys_call
>> 484 ret_from_sys_call:
>> 485 cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
>> 486 ldq $0, SP_OFF($sp)
>> 487 and $0, 8, $0
>> 488 beq $0, ret_to_kernel
>> 489 ret_to_user:
>> 490 /* Make sure need_resched and sigpending don't change between
>> 491 sampling and the rti. */
>> 492 lda $16, 7
>> 493 call_pal PAL_swpipl
>> 494 ldl $17, TI_FLAGS($8)
>> 495 and $17, _TIF_WORK_MASK, $2
>> 496 bne $2, work_pending
>> 497 restore_all:
>> 498 .cfi_remember_state
>> 499 RESTORE_ALL
>> 500 call_pal PAL_rti
>> 501
>> 502 ret_to_kernel:
>> 503 .cfi_restore_state
>> 504 lda $16, 7
>> 505 call_pal PAL_swpipl
>> 506 br restore_all
>> 507
>> 508 .align 3
>> 509 $syscall_error:
>> 510 /*
>> 511 * Some system calls (e.g., ptrace) can return arbitrary
>> 512 * values which might normally be mistaken as error numbers.
>> 513 * Those functions must zero $0 (v0) directly in the stack
>> 514 * frame to indicate that a negative return value wasn't an
>> 515 * error number..
>> 516 */
>> 517 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 518 beq $18, $ret_success
>> 519
>> 520 ldq $19, 72($sp) /* .. and this a3 */
>> 521 subq $31, $0, $0 /* with error in v0 */
>> 522 addq $31, 1, $1 /* set a3 for errno return */
>> 523 stq $0, 0($sp)
>> 524 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
>> 525 stq $1, 72($sp) /* a3 for return */
>> 526 br ret_from_sys_call
>> 527
>> 528 $ret_success:
>> 529 stq $0, 0($sp)
>> 530 stq $31, 72($sp) /* a3=0 => no error */
>> 531 br ret_from_sys_call
312 532
313 ; --- (Slow Path #3) notify_resume --- !! 533 /*
314 .Lchk_notify_resume: !! 534 * Do all cleanup when returning from all interrupts and system calls.
315 btst r9, TIF_NOTIFY_RESUME !! 535 *
316 blnz @do_notify_resume !! 536 * Arguments:
317 b resume_user_mode_begin ; unco !! 537 * $8: current.
318 ; for !! 538 * $17: TI_FLAGS.
>> 539 * $18: The old syscall number, or zero if this is not a return
>> 540 * from a syscall that errored and is possibly restartable.
>> 541 * $19: The old a3 value
>> 542 */
319 543
320 resume_kernel_mode: !! 544 .align 4
>> 545 .type work_pending, @function
>> 546 work_pending:
>> 547 and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL, $2
>> 548 bne $2, $work_notifysig
>> 549
>> 550 $work_resched:
>> 551 /*
>> 552 * We can get here only if we returned from syscall without SIGPENDING
>> 553 * or got through work_notifysig already. Either case means no syscall
>> 554 * restarts for us, so let $18 and $19 burn.
>> 555 */
>> 556 jsr $26, schedule
>> 557 mov 0, $18
>> 558 br ret_to_user
>> 559
>> 560 $work_notifysig:
>> 561 mov $sp, $16
>> 562 DO_SWITCH_STACK
>> 563 jsr $26, do_work_pending
>> 564 UNDO_SWITCH_STACK
>> 565 br restore_all
321 566
322 ; Disable Interrupts from this point o !! 567 /*
323 ; CONFIG_PREEMPTION: This is a must fo !! 568 * PTRACE syscall handler
324 ; !CONFIG_PREEMPTION: To ensure restor !! 569 */
325 IRQ_DISABLE r9 <<
326 570
327 #ifdef CONFIG_PREEMPTION !! 571 .align 4
>> 572 .type strace, @function
>> 573 strace:
>> 574 /* set up signal stack, call syscall_trace */
>> 575 DO_SWITCH_STACK
>> 576 jsr $26, syscall_trace_enter /* returns the syscall number */
>> 577 UNDO_SWITCH_STACK
>> 578
>> 579 /* get the arguments back.. */
>> 580 ldq $16, SP_OFF+24($sp)
>> 581 ldq $17, SP_OFF+32($sp)
>> 582 ldq $18, SP_OFF+40($sp)
>> 583 ldq $19, 72($sp)
>> 584 ldq $20, 80($sp)
>> 585 ldq $21, 88($sp)
>> 586
>> 587 /* get the system call pointer.. */
>> 588 lda $1, NR_SYSCALLS($31)
>> 589 lda $2, sys_call_table
>> 590 lda $27, sys_ni_syscall
>> 591 cmpult $0, $1, $1
>> 592 s8addq $0, $2, $2
>> 593 beq $1, 1f
>> 594 ldq $27, 0($2)
>> 595 1: jsr $26, ($27), sys_gettimeofday
>> 596 ret_from_straced:
>> 597 ldgp $gp, 0($26)
>> 598
>> 599 /* check return.. */
>> 600 blt $0, $strace_error /* the call failed */
>> 601 stq $31, 72($sp) /* a3=0 => no error */
>> 602 $strace_success:
>> 603 stq $0, 0($sp) /* save return value */
>> 604
>> 605 DO_SWITCH_STACK
>> 606 jsr $26, syscall_trace_leave
>> 607 UNDO_SWITCH_STACK
>> 608 br $31, ret_from_sys_call
>> 609
>> 610 .align 3
>> 611 $strace_error:
>> 612 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 613 beq $18, $strace_success
>> 614 ldq $19, 72($sp) /* .. and this a3 */
>> 615
>> 616 subq $31, $0, $0 /* with error in v0 */
>> 617 addq $31, 1, $1 /* set a3 for errno return */
>> 618 stq $0, 0($sp)
>> 619 stq $1, 72($sp) /* a3 for return */
>> 620
>> 621 DO_SWITCH_STACK
>> 622 mov $18, $9 /* save old syscall number */
>> 623 mov $19, $10 /* save old a3 */
>> 624 jsr $26, syscall_trace_leave
>> 625 mov $9, $18
>> 626 mov $10, $19
>> 627 UNDO_SWITCH_STACK
>> 628
>> 629 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
>> 630 br ret_from_sys_call
>> 631 CFI_END_OSF_FRAME entSys
>> 632
>> 633 /*
>> 634 * Save and restore the switch stack -- aka the balance of the user context.
>> 635 */
328 636
329 ; Can't preempt if preemption disabled !! 637 .align 4
330 GET_CURR_THR_INFO_FROM_SP r10 !! 638 .type do_switch_stack, @function
331 ld r8, [r10, THREAD_INFO_PREEMPT_COUN !! 639 .cfi_startproc simple
332 brne r8, 0, .Lrestore_regs !! 640 .cfi_return_column 64
>> 641 .cfi_def_cfa $sp, 0
>> 642 .cfi_register 64, $1
>> 643 do_switch_stack:
>> 644 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 645 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 646 stq $9, 0($sp)
>> 647 stq $10, 8($sp)
>> 648 stq $11, 16($sp)
>> 649 stq $12, 24($sp)
>> 650 stq $13, 32($sp)
>> 651 stq $14, 40($sp)
>> 652 stq $15, 48($sp)
>> 653 stq $26, 56($sp)
>> 654 stt $f0, 64($sp)
>> 655 stt $f1, 72($sp)
>> 656 stt $f2, 80($sp)
>> 657 stt $f3, 88($sp)
>> 658 stt $f4, 96($sp)
>> 659 stt $f5, 104($sp)
>> 660 stt $f6, 112($sp)
>> 661 stt $f7, 120($sp)
>> 662 stt $f8, 128($sp)
>> 663 stt $f9, 136($sp)
>> 664 stt $f10, 144($sp)
>> 665 stt $f11, 152($sp)
>> 666 stt $f12, 160($sp)
>> 667 stt $f13, 168($sp)
>> 668 stt $f14, 176($sp)
>> 669 stt $f15, 184($sp)
>> 670 stt $f16, 192($sp)
>> 671 stt $f17, 200($sp)
>> 672 stt $f18, 208($sp)
>> 673 stt $f19, 216($sp)
>> 674 stt $f20, 224($sp)
>> 675 stt $f21, 232($sp)
>> 676 stt $f22, 240($sp)
>> 677 stt $f23, 248($sp)
>> 678 stt $f24, 256($sp)
>> 679 stt $f25, 264($sp)
>> 680 stt $f26, 272($sp)
>> 681 stt $f27, 280($sp)
>> 682 mf_fpcr $f0 # get fpcr
>> 683 stt $f28, 288($sp)
>> 684 stt $f29, 296($sp)
>> 685 stt $f30, 304($sp)
>> 686 stt $f0, 312($sp) # save fpcr in slot of $f31
>> 687 ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
>> 688 ret $31, ($1), 1
>> 689 .cfi_endproc
>> 690 .size do_switch_stack, .-do_switch_stack
>> 691
>> 692 .align 4
>> 693 .type undo_switch_stack, @function
>> 694 .cfi_startproc simple
>> 695 .cfi_def_cfa $sp, 0
>> 696 .cfi_register 64, $1
>> 697 undo_switch_stack:
>> 698 ldq $9, 0($sp)
>> 699 ldq $10, 8($sp)
>> 700 ldq $11, 16($sp)
>> 701 ldq $12, 24($sp)
>> 702 ldq $13, 32($sp)
>> 703 ldq $14, 40($sp)
>> 704 ldq $15, 48($sp)
>> 705 ldq $26, 56($sp)
>> 706 ldt $f30, 312($sp) # get saved fpcr
>> 707 ldt $f0, 64($sp)
>> 708 ldt $f1, 72($sp)
>> 709 ldt $f2, 80($sp)
>> 710 ldt $f3, 88($sp)
>> 711 mt_fpcr $f30 # install saved fpcr
>> 712 ldt $f4, 96($sp)
>> 713 ldt $f5, 104($sp)
>> 714 ldt $f6, 112($sp)
>> 715 ldt $f7, 120($sp)
>> 716 ldt $f8, 128($sp)
>> 717 ldt $f9, 136($sp)
>> 718 ldt $f10, 144($sp)
>> 719 ldt $f11, 152($sp)
>> 720 ldt $f12, 160($sp)
>> 721 ldt $f13, 168($sp)
>> 722 ldt $f14, 176($sp)
>> 723 ldt $f15, 184($sp)
>> 724 ldt $f16, 192($sp)
>> 725 ldt $f17, 200($sp)
>> 726 ldt $f18, 208($sp)
>> 727 ldt $f19, 216($sp)
>> 728 ldt $f20, 224($sp)
>> 729 ldt $f21, 232($sp)
>> 730 ldt $f22, 240($sp)
>> 731 ldt $f23, 248($sp)
>> 732 ldt $f24, 256($sp)
>> 733 ldt $f25, 264($sp)
>> 734 ldt $f26, 272($sp)
>> 735 ldt $f27, 280($sp)
>> 736 ldt $f28, 288($sp)
>> 737 ldt $f29, 296($sp)
>> 738 ldt $f30, 304($sp)
>> 739 lda $sp, SWITCH_STACK_SIZE($sp)
>> 740 ret $31, ($1), 1
>> 741 .cfi_endproc
>> 742 .size undo_switch_stack, .-undo_switch_stack
>> 743
>> 744 /*
>> 745 * The meat of the context switch code.
>> 746 */
333 747
334 ; check if this task's NEED_RESCHED fl !! 748 .align 4
335 ld r9, [r10, THREAD_INFO_FLAGS] !! 749 .globl alpha_switch_to
336 bbit0 r9, TIF_NEED_RESCHED, .Lrestore !! 750 .type alpha_switch_to, @function
>> 751 .cfi_startproc
>> 752 alpha_switch_to:
>> 753 DO_SWITCH_STACK
>> 754 call_pal PAL_swpctx
>> 755 lda $8, 0x3fff
>> 756 UNDO_SWITCH_STACK
>> 757 bic $sp, $8, $8
>> 758 mov $17, $0
>> 759 ret
>> 760 .cfi_endproc
>> 761 .size alpha_switch_to, .-alpha_switch_to
337 762
338 ; Invoke PREEMPTION !! 763 /*
339 jl preempt_schedule_irq !! 764 * New processes begin life here.
>> 765 */
340 766
341 ; preempt_schedule_irq() always return !! 767 .globl ret_from_fork
342 #endif !! 768 .align 4
>> 769 .ent ret_from_fork
>> 770 ret_from_fork:
>> 771 lda $26, ret_from_sys_call
>> 772 mov $17, $16
>> 773 jmp $31, schedule_tail
>> 774 .end ret_from_fork
343 775
344 b .Lrestore_regs !! 776 /*
>> 777 * ... and new kernel threads - here
>> 778 */
>> 779 .align 4
>> 780 .globl ret_from_kernel_thread
>> 781 .ent ret_from_kernel_thread
>> 782 ret_from_kernel_thread:
>> 783 mov $17, $16
>> 784 jsr $26, schedule_tail
>> 785 mov $9, $27
>> 786 mov $10, $16
>> 787 jsr $26, ($9)
>> 788 br $31, ret_to_user
>> 789 .end ret_from_kernel_thread
345 790
346 ##### DONT ADD CODE HERE - .Lrestore_regs actu !! 791
>> 792 /*
>> 793 * Special system calls. Most of these are special in that they either
>> 794 * have to play switch_stack games.
>> 795 */
347 796
>> 797 .macro fork_like name
>> 798 .align 4
>> 799 .globl alpha_\name
>> 800 .ent alpha_\name
>> 801 alpha_\name:
>> 802 .prologue 0
>> 803 bsr $1, do_switch_stack
>> 804 jsr $26, sys_\name
>> 805 ldq $26, 56($sp)
>> 806 lda $sp, SWITCH_STACK_SIZE($sp)
>> 807 ret
>> 808 .end alpha_\name
>> 809 .endm
>> 810
>> 811 fork_like fork
>> 812 fork_like vfork
>> 813 fork_like clone
>> 814
>> 815 .macro sigreturn_like name
>> 816 .align 4
>> 817 .globl sys_\name
>> 818 .ent sys_\name
>> 819 sys_\name:
>> 820 .prologue 0
>> 821 lda $9, ret_from_straced
>> 822 cmpult $26, $9, $9
>> 823 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 824 jsr $26, do_\name
>> 825 bne $9, 1f
>> 826 jsr $26, syscall_trace_leave
>> 827 1: br $1, undo_switch_stack
>> 828 br ret_from_sys_call
>> 829 .end sys_\name
>> 830 .endm
>> 831
>> 832 sigreturn_like sigreturn
>> 833 sigreturn_like rt_sigreturn
>> 834
>> 835 .align 4
>> 836 .globl alpha_syscall_zero
>> 837 .ent alpha_syscall_zero
>> 838 alpha_syscall_zero:
>> 839 .prologue 0
>> 840 /* Special because it needs to do something opposite to
>> 841 force_successful_syscall_return(). We use the saved
>> 842 syscall number for that, zero meaning "not an error".
>> 843 That works nicely, but for real syscall 0 we need to
>> 844 make sure that this logics doesn't get confused.
>> 845 Store a non-zero there - -ENOSYS we need in register
>> 846 for our return value will do just fine.
>> 847 */
>> 848 lda $0, -ENOSYS
>> 849 unop
>> 850 stq $0, 0($sp)
>> 851 ret
>> 852 .end alpha_syscall_zero
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