1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * S390 64-bit swsusp implementation 4 * 5 * Copyright IBM Corp. 2009 6 * 7 * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com> 8 * Michael Holzheu <holzheu@linux.vnet.ibm.com> 9 */ 10 11#include <linux/linkage.h> 12#include <asm/page.h> 13#include <asm/ptrace.h> 14#include <asm/thread_info.h> 15#include <asm/asm-offsets.h> 16#include <asm/nospec-insn.h> 17#include <asm/sigp.h> 18 19/* 20 * Save register context in absolute 0 lowcore and call swsusp_save() to 21 * create in-memory kernel image. The context is saved in the designated 22 * "store status" memory locations (see POP). 23 * We return from this function twice. The first time during the suspend to 24 * disk process. The second time via the swsusp_arch_resume() function 25 * (see below) in the resume process. 26 * This function runs with disabled interrupts. 27 */ 28 GEN_BR_THUNK %r14 29 30 .section .text 31ENTRY(swsusp_arch_suspend) 32 lg %r1,__LC_NODAT_STACK 33 stmg %r6,%r15,__SF_GPRS(%r1) 34 aghi %r1,-STACK_FRAME_OVERHEAD 35 stg %r15,__SF_BACKCHAIN(%r1) 36 lgr %r15,%r1 37 38 /* Store FPU registers */ 39 brasl %r14,save_fpu_regs 40 41 /* Deactivate DAT */ 42 stnsm __SF_EMPTY(%r15),0xfb 43 44 /* Store prefix register on stack */ 45 stpx __SF_EMPTY(%r15) 46 47 /* Save prefix register contents for lowcore copy */ 48 llgf %r10,__SF_EMPTY(%r15) 49 50 /* Get pointer to save area */ 51 lghi %r1,0x1000 52 53 /* Save CPU address */ 54 stap __LC_EXT_CPU_ADDR(%r0) 55 56 /* Store registers */ 57 mvc 0x318(4,%r1),__SF_EMPTY(%r15) /* move prefix to lowcore */ 58 stam %a0,%a15,0x340(%r1) /* store access registers */ 59 stctg %c0,%c15,0x380(%r1) /* store control registers */ 60 stmg %r0,%r15,0x280(%r1) /* store general registers */ 61 62 stpt 0x328(%r1) /* store timer */ 63 stck __SF_EMPTY(%r15) /* store clock */ 64 stckc 0x330(%r1) /* store clock comparator */ 65 66 /* Update cputime accounting before going to sleep */ 67 lg %r0,__LC_LAST_UPDATE_TIMER 68 slg %r0,0x328(%r1) 69 alg %r0,__LC_SYSTEM_TIMER 70 stg %r0,__LC_SYSTEM_TIMER 71 mvc __LC_LAST_UPDATE_TIMER(8),0x328(%r1) 72 lg %r0,__LC_LAST_UPDATE_CLOCK 73 slg %r0,__SF_EMPTY(%r15) 74 alg %r0,__LC_STEAL_TIMER 75 stg %r0,__LC_STEAL_TIMER 76 mvc __LC_LAST_UPDATE_CLOCK(8),__SF_EMPTY(%r15) 77 78 /* Activate DAT */ 79 stosm __SF_EMPTY(%r15),0x04 80 81 /* Set prefix page to zero */ 82 xc __SF_EMPTY(4,%r15),__SF_EMPTY(%r15) 83 spx __SF_EMPTY(%r15) 84 85 /* Save absolute zero pages */ 86 larl %r2,suspend_zero_pages 87 lg %r2,0(%r2) 88 lghi %r4,0 89 lghi %r3,2*PAGE_SIZE 90 lghi %r5,2*PAGE_SIZE 911: mvcle %r2,%r4,0 92 jo 1b 93 94 /* Copy lowcore to absolute zero lowcore */ 95 lghi %r2,0 96 lgr %r4,%r10 97 lghi %r3,2*PAGE_SIZE 98 lghi %r5,2*PAGE_SIZE 991: mvcle %r2,%r4,0 100 jo 1b 101 102 /* Save image */ 103 brasl %r14,swsusp_save 104 105 /* Restore prefix register and return */ 106 lghi %r1,0x1000 107 spx 0x318(%r1) 108 lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15) 109 lghi %r2,0 110 BR_EX %r14 111ENDPROC(swsusp_arch_suspend) 112 113/* 114 * Restore saved memory image to correct place and restore register context. 115 * Then we return to the function that called swsusp_arch_suspend(). 116 * swsusp_arch_resume() runs with disabled interrupts. 117 */ 118ENTRY(swsusp_arch_resume) 119 stmg %r6,%r15,__SF_GPRS(%r15) 120 lgr %r1,%r15 121 aghi %r15,-STACK_FRAME_OVERHEAD 122 stg %r1,__SF_BACKCHAIN(%r15) 123 124 /* Make all free pages stable */ 125 lghi %r2,1 126 brasl %r14,arch_set_page_states 127 128 /* Set prefix page to zero */ 129 xc __SF_EMPTY(4,%r15),__SF_EMPTY(%r15) 130 spx __SF_EMPTY(%r15) 131 132 /* Deactivate DAT */ 133 stnsm __SF_EMPTY(%r15),0xfb 134 135 /* Restore saved image */ 136 larl %r1,restore_pblist 137 lg %r1,0(%r1) 138 ltgr %r1,%r1 139 jz 2f 1400: 141 lg %r2,8(%r1) 142 lg %r4,0(%r1) 143 iske %r0,%r4 144 lghi %r3,PAGE_SIZE 145 lghi %r5,PAGE_SIZE 1461: 147 mvcle %r2,%r4,0 148 jo 1b 149 lg %r2,8(%r1) 150 sske %r0,%r2 151 lg %r1,16(%r1) 152 ltgr %r1,%r1 153 jnz 0b 1542: 155 ptlb /* flush tlb */ 156 157 /* Reset System */ 158 larl %r1,.Lnew_pgm_check_psw 159 epsw %r2,%r3 160 stm %r2,%r3,0(%r1) 161 mvc __LC_PGM_NEW_PSW(16,%r0),0(%r1) 162 larl %r1,__swsusp_reset_dma 163 lg %r1,0(%r1) 164 BASR_EX %r14,%r1 165 larl %r1,smp_cpu_mt_shift 166 icm %r1,15,0(%r1) 167 jz smt_done 168 llgfr %r1,%r1 169smt_loop: 170 sigp %r1,%r0,SIGP_SET_MULTI_THREADING 171 brc 8,smt_done /* accepted */ 172 brc 2,smt_loop /* busy, try again */ 173smt_done: 174 larl %r1,.Lnew_pgm_check_psw 175 lpswe 0(%r1) 176pgm_check_entry: 177 178 /* Switch to original suspend CPU */ 179 larl %r1,.Lresume_cpu /* Resume CPU address: r2 */ 180 stap 0(%r1) 181 llgh %r2,0(%r1) 182 llgh %r1,__LC_EXT_CPU_ADDR(%r0) /* Suspend CPU address: r1 */ 183 cgr %r1,%r2 184 je restore_registers /* r1 = r2 -> nothing to do */ 185 larl %r4,.Lrestart_suspend_psw /* Set new restart PSW */ 186 mvc __LC_RST_NEW_PSW(16,%r0),0(%r4) 1873: 188 sigp %r9,%r1,SIGP_INITIAL_CPU_RESET /* sigp initial cpu reset */ 189 brc 8,4f /* accepted */ 190 brc 2,3b /* busy, try again */ 191 192 /* Suspend CPU not available -> panic */ 193 larl %r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD 194 larl %r2,.Lpanic_string 195 brasl %r14,sclp_early_printk_force 196 larl %r3,.Ldisabled_wait_31 197 lpsw 0(%r3) 1984: 199 /* Switch to suspend CPU */ 200 sigp %r9,%r1,SIGP_RESTART /* sigp restart to suspend CPU */ 201 brc 2,4b /* busy, try again */ 2025: 203 sigp %r9,%r2,SIGP_STOP /* sigp stop to current resume CPU */ 204 brc 2,5b /* busy, try again */ 2056: j 6b 206 207restart_suspend: 208 larl %r1,.Lresume_cpu 209 llgh %r2,0(%r1) 2107: 211 sigp %r9,%r2,SIGP_SENSE /* sigp sense, wait for resume CPU */ 212 brc 8,7b /* accepted, status 0, still running */ 213 brc 2,7b /* busy, try again */ 214 tmll %r9,0x40 /* Test if resume CPU is stopped */ 215 jz 7b 216 217restore_registers: 218 /* Restore registers */ 219 lghi %r13,0x1000 /* %r1 = pointer to save area */ 220 221 /* Ignore time spent in suspended state. */ 222 llgf %r1,0x318(%r13) 223 stck __LC_LAST_UPDATE_CLOCK(%r1) 224 spt 0x328(%r13) /* reprogram timer */ 225 //sckc 0x330(%r13) /* set clock comparator */ 226 227 lctlg %c0,%c15,0x380(%r13) /* load control registers */ 228 lam %a0,%a15,0x340(%r13) /* load access registers */ 229 230 /* Load old stack */ 231 lg %r15,0x2f8(%r13) 232 233 /* Save prefix register */ 234 mvc __SF_EMPTY(4,%r15),0x318(%r13) 235 236 /* Restore absolute zero pages */ 237 lghi %r2,0 238 larl %r4,suspend_zero_pages 239 lg %r4,0(%r4) 240 lghi %r3,2*PAGE_SIZE 241 lghi %r5,2*PAGE_SIZE 2421: mvcle %r2,%r4,0 243 jo 1b 244 245 /* Restore prefix register */ 246 spx __SF_EMPTY(%r15) 247 248 /* Activate DAT */ 249 stosm __SF_EMPTY(%r15),0x04 250 251 /* Make all free pages unstable */ 252 lghi %r2,0 253 brasl %r14,arch_set_page_states 254 255 /* Call arch specific early resume code */ 256 brasl %r14,s390_early_resume 257 258 /* Return 0 */ 259 lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15) 260 lghi %r2,0 261 BR_EX %r14 262ENDPROC(swsusp_arch_resume) 263 264 .section .data..nosave,"aw",@progbits 265 .align 8 266.Ldisabled_wait_31: 267 .long 0x000a0000,0x00000000 268.Lpanic_string: 269 .asciz "Resume not possible because suspend CPU is no longer available\n" 270 .align 8 271.Lrestart_suspend_psw: 272 .quad 0x0000000180000000,restart_suspend 273.Lnew_pgm_check_psw: 274 .quad 0,pgm_check_entry 275.Lresume_cpu: 276 .byte 0,0 277