projects / mirror_ubuntu-kernels.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) | |
| 3 | * | |
| dde39798 HD |
4 | * System call entry code / Linux gateway page |
| 5 | * Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai> | |
| 1da177e4 LT |
6 | * Licensed under the GNU GPL. |
| 7 | * thanks to Philipp Rumpf, Mike Shaver and various others | |
| 8 | * sorry about the wall, puffin.. | |
| 9 | */ | |
| 10 | ||
| dde39798 HD |
11 | /* |
| 12 | How does the Linux gateway page on PA-RISC work? | |
| 13 | ------------------------------------------------ | |
| 14 | The Linux gateway page on PA-RISC is "special". | |
| 15 | It actually has PAGE_GATEWAY bits set (this is linux terminology; in parisc | |
| 16 | terminology it's Execute, promote to PL0) in the page map. So anything | |
| 17 | executing on this page executes with kernel level privilege (there's more to it | |
| 18 | than that: to have this happen, you also have to use a branch with a ,gate | |
| 19 | completer to activate the privilege promotion). The upshot is that everything | |
| 20 | that runs on the gateway page runs at kernel privilege but with the current | |
| 21 | user process address space (although you have access to kernel space via %sr2). | |
| 22 | For the 0x100 syscall entry, we redo the space registers to point to the kernel | |
| 23 | address space (preserving the user address space in %sr3), move to wide mode if | |
| 24 | required, save the user registers and branch into the kernel syscall entry | |
| 25 | point. For all the other functions, we execute at kernel privilege but don't | |
| 26 | flip address spaces. The basic upshot of this is that these code snippets are | |
| 27 | executed atomically (because the kernel can't be pre-empted) and they may | |
| 28 | perform architecturally forbidden (to PL3) operations (like setting control | |
| 29 | registers). | |
| 30 | */ | |
| 31 | ||
| 32 | ||
| 0013a854 | 33 | #include <asm/asm-offsets.h> |
| 1da177e4 LT |
34 | #include <asm/unistd.h> |
| 35 | #include <asm/errno.h> | |
| 1c593571 | 36 | #include <asm/page.h> |
| 1da177e4 LT |
37 | #include <asm/psw.h> |
| 38 | #include <asm/thread_info.h> | |
| 1da177e4 LT |
39 | #include <asm/assembly.h> |
| 40 | #include <asm/processor.h> | |
| 6a45716a | 41 | #include <asm/cache.h> |
| 1da177e4 | 42 | |
| 8e9e9844 HD |
43 | #include <linux/linkage.h> |
| 44 | ||
| 1da177e4 LT |
45 | /* We fill the empty parts of the gateway page with |
| 46 | * something that will kill the kernel or a | |
| 47 | * userspace application. | |
| 48 | */ | |
| 49 | #define KILL_INSN break 0,0 | |
| 50 | ||
| 0b3d643f | 51 | .level LEVEL |
| 8e9e9844 | 52 | |
| dfcf753b | 53 | .text |
| 1da177e4 LT |
54 | |
| 55 | .import syscall_exit,code | |
| 56 | .import syscall_exit_rfi,code | |
| 1da177e4 LT |
57 | |
| 58 | /* Linux gateway page is aliased to virtual page 0 in the kernel | |
| 59 | * address space. Since it is a gateway page it cannot be | |
| 60 | * dereferenced, so null pointers will still fault. We start | |
| 61 | * the actual entry point at 0x100. We put break instructions | |
| 62 | * at the beginning of the page to trap null indirect function | |
| 63 | * pointers. | |
| 64 | */ | |
| 65 | ||
| 1c593571 | 66 | .align PAGE_SIZE |
| 8e9e9844 | 67 | ENTRY(linux_gateway_page) |
| 1da177e4 LT |
68 | |
| 69 | /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */ | |
| 70 | .rept 44 | |
| 71 | KILL_INSN | |
| 72 | .endr | |
| 73 | ||
| f4c0346c | 74 | /* ADDRESS 0xb0 to 0xb8, lws uses two insns for entry */ |
| 1da177e4 LT |
75 | /* Light-weight-syscall entry must always be located at 0xb0 */ |
| 76 | /* WARNING: Keep this number updated with table size changes */ | |
| 89206491 | 77 | #define __NR_lws_entries (3) |
| 1da177e4 LT |
78 | |
| 79 | lws_entry: | |
| f4c0346c JDA |
80 | gate lws_start, %r0 /* increase privilege */ |
| 81 | depi 3, 31, 2, %r31 /* Ensure we return into user mode. */ | |
| 1da177e4 | 82 | |
| f4c0346c JDA |
83 | /* Fill from 0xb8 to 0xe0 */ |
| 84 | .rept 10 | |
| 1da177e4 LT |
85 | KILL_INSN |
| 86 | .endr | |
| 87 | ||
| 88 | /* This function MUST be located at 0xe0 for glibc's threading | |
| 89 | mechanism to work. DO NOT MOVE THIS CODE EVER! */ | |
| 90 | set_thread_pointer: | |
| 91 | gate .+8, %r0 /* increase privilege */ | |
| 92 | depi 3, 31, 2, %r31 /* Ensure we return into user mode. */ | |
| 93 | be 0(%sr7,%r31) /* return to user space */ | |
| 94 | mtctl %r26, %cr27 /* move arg0 to the control register */ | |
| 95 | ||
| 96 | /* Increase the chance of trapping if random jumps occur to this | |
| 97 | address, fill from 0xf0 to 0x100 */ | |
| 98 | .rept 4 | |
| 99 | KILL_INSN | |
| 100 | .endr | |
| 101 | ||
| 102 | /* This address must remain fixed at 0x100 for glibc's syscalls to work */ | |
| 103 | .align 256 | |
| 104 | linux_gateway_entry: | |
| 105 | gate .+8, %r0 /* become privileged */ | |
| 106 | mtsp %r0,%sr4 /* get kernel space into sr4 */ | |
| 107 | mtsp %r0,%sr5 /* get kernel space into sr5 */ | |
| 108 | mtsp %r0,%sr6 /* get kernel space into sr6 */ | |
| 109 | mfsp %sr7,%r1 /* save user sr7 */ | |
| 110 | mtsp %r1,%sr3 /* and store it in sr3 */ | |
| 111 | ||
| 413059f2 | 112 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
113 | /* for now we can *always* set the W bit on entry to the syscall |
| 114 | * since we don't support wide userland processes. We could | |
| 115 | * also save the current SM other than in r0 and restore it on | |
| 116 | * exit from the syscall, and also use that value to know | |
| 117 | * whether to do narrow or wide syscalls. -PB | |
| 118 | */ | |
| 119 | ssm PSW_SM_W, %r1 | |
| 120 | extrd,u %r1,PSW_W_BIT,1,%r1 | |
| 121 | /* sp must be aligned on 4, so deposit the W bit setting into | |
| 122 | * the bottom of sp temporarily */ | |
| 123 | or,ev %r1,%r30,%r30 | |
| 124 | b,n 1f | |
| 125 | /* The top halves of argument registers must be cleared on syscall | |
| 126 | * entry from narrow executable. | |
| 127 | */ | |
| 128 | depdi 0, 31, 32, %r26 | |
| 129 | depdi 0, 31, 32, %r25 | |
| 130 | depdi 0, 31, 32, %r24 | |
| 131 | depdi 0, 31, 32, %r23 | |
| 132 | depdi 0, 31, 32, %r22 | |
| 133 | depdi 0, 31, 32, %r21 | |
| 134 | 1: | |
| 135 | #endif | |
| 136 | mfctl %cr30,%r1 | |
| 137 | xor %r1,%r30,%r30 /* ye olde xor trick */ | |
| 138 | xor %r1,%r30,%r1 | |
| 139 | xor %r1,%r30,%r30 | |
| 140 | ||
| 141 | ldo THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30 /* set up kernel stack */ | |
| 142 | ||
| 143 | /* N.B.: It is critical that we don't set sr7 to 0 until r30 | |
| 144 | * contains a valid kernel stack pointer. It is also | |
| 145 | * critical that we don't start using the kernel stack | |
| 146 | * until after sr7 has been set to 0. | |
| 147 | */ | |
| 148 | ||
| 149 | mtsp %r0,%sr7 /* get kernel space into sr7 */ | |
| 150 | STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ | |
| 151 | mfctl %cr30,%r1 /* get task ptr in %r1 */ | |
| 152 | LDREG TI_TASK(%r1),%r1 | |
| 153 | ||
| 154 | /* Save some registers for sigcontext and potential task | |
| 155 | switch (see entry.S for the details of which ones are | |
| 156 | saved/restored). TASK_PT_PSW is zeroed so we can see whether | |
| 157 | a process is on a syscall or not. For an interrupt the real | |
| 158 | PSW value is stored. This is needed for gdb and sys_ptrace. */ | |
| 159 | STREG %r0, TASK_PT_PSW(%r1) | |
| 160 | STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */ | |
| 161 | STREG %r19, TASK_PT_GR19(%r1) | |
| 162 | ||
| 163 | LDREGM -FRAME_SIZE(%r30), %r2 /* get users sp back */ | |
| 413059f2 | 164 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
165 | extrd,u %r2,63,1,%r19 /* W hidden in bottom bit */ |
| 166 | #if 0 | |
| 167 | xor %r19,%r2,%r2 /* clear bottom bit */ | |
| 168 | depd,z %r19,1,1,%r19 | |
| 169 | std %r19,TASK_PT_PSW(%r1) | |
| 170 | #endif | |
| 171 | #endif | |
| 172 | STREG %r2, TASK_PT_GR30(%r1) /* ... and save it */ | |
| 173 | ||
| aa0eecb0 | 174 | STREG %r20, TASK_PT_GR20(%r1) /* Syscall number */ |
| 1da177e4 LT |
175 | STREG %r21, TASK_PT_GR21(%r1) |
| 176 | STREG %r22, TASK_PT_GR22(%r1) | |
| 177 | STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */ | |
| 178 | STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */ | |
| 179 | STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */ | |
| 180 | STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */ | |
| 181 | STREG %r27, TASK_PT_GR27(%r1) /* user dp */ | |
| 182 | STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */ | |
| 00df111e | 183 | STREG %r0, TASK_PT_ORIG_R28(%r1) /* don't prohibit restarts */ |
| 1da177e4 LT |
184 | STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */ |
| 185 | STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */ | |
| 186 | ||
| 187 | ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */ | |
| 188 | save_fp %r27 /* or potential task switch */ | |
| 189 | ||
| 190 | mfctl %cr11, %r27 /* i.e. SAR */ | |
| 191 | STREG %r27, TASK_PT_SAR(%r1) | |
| 192 | ||
| 193 | loadgp | |
| 194 | ||
| 413059f2 | 195 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
196 | ldo -16(%r30),%r29 /* Reference param save area */ |
| 197 | copy %r19,%r2 /* W bit back to r2 */ | |
| 198 | #else | |
| 199 | /* no need to save these on stack in wide mode because the first 8 | |
| 200 | * args are passed in registers */ | |
| 201 | stw %r22, -52(%r30) /* 5th argument */ | |
| 202 | stw %r21, -56(%r30) /* 6th argument */ | |
| 203 | #endif | |
| 204 | ||
| 205 | /* Are we being ptraced? */ | |
| 206 | mfctl %cr30, %r1 | |
| 64482bd8 AV |
207 | LDREG TI_FLAGS(%r1),%r1 |
| 208 | ldi _TIF_SYSCALL_TRACE_MASK, %r19 | |
| 209 | and,COND(=) %r1, %r19, %r0 | |
| 210 | b,n .Ltracesys | |
| 1da177e4 LT |
211 | |
| 212 | /* Note! We cannot use the syscall table that is mapped | |
| 213 | nearby since the gateway page is mapped execute-only. */ | |
| 214 | ||
| 413059f2 | 215 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
216 | ldil L%sys_call_table, %r1 |
| 217 | or,= %r2,%r2,%r2 | |
| 218 | addil L%(sys_call_table64-sys_call_table), %r1 | |
| 219 | ldo R%sys_call_table(%r1), %r19 | |
| 220 | or,= %r2,%r2,%r2 | |
| 221 | ldo R%sys_call_table64(%r1), %r19 | |
| 222 | #else | |
| 223 | ldil L%sys_call_table, %r1 | |
| 224 | ldo R%sys_call_table(%r1), %r19 | |
| 225 | #endif | |
| 3bb457af | 226 | comiclr,>> __NR_Linux_syscalls, %r20, %r0 |
| 1da177e4 LT |
227 | b,n .Lsyscall_nosys |
| 228 | ||
| 229 | LDREGX %r20(%r19), %r19 | |
| 230 | ||
| 231 | /* If this is a sys_rt_sigreturn call, and the signal was received | |
| 232 | * when not in_syscall, then we want to return via syscall_exit_rfi, | |
| 233 | * not syscall_exit. Signal no. in r20, in_syscall in r25 (see | |
| 234 | * trampoline code in signal.c). | |
| 235 | */ | |
| 236 | ldi __NR_rt_sigreturn,%r2 | |
| 237 | comb,= %r2,%r20,.Lrt_sigreturn | |
| 238 | .Lin_syscall: | |
| 239 | ldil L%syscall_exit,%r2 | |
| 240 | be 0(%sr7,%r19) | |
| 241 | ldo R%syscall_exit(%r2),%r2 | |
| 242 | .Lrt_sigreturn: | |
| 243 | comib,<> 0,%r25,.Lin_syscall | |
| 244 | ldil L%syscall_exit_rfi,%r2 | |
| 245 | be 0(%sr7,%r19) | |
| 246 | ldo R%syscall_exit_rfi(%r2),%r2 | |
| 247 | ||
| 248 | /* Note! Because we are not running where we were linked, any | |
| 249 | calls to functions external to this file must be indirect. To | |
| 250 | be safe, we apply the opposite rule to functions within this | |
| 251 | file, with local labels given to them to ensure correctness. */ | |
| 252 | ||
| 253 | .Lsyscall_nosys: | |
| 254 | syscall_nosys: | |
| 255 | ldil L%syscall_exit,%r1 | |
| 256 | be R%syscall_exit(%sr7,%r1) | |
| 257 | ldo -ENOSYS(%r0),%r28 /* set errno */ | |
| 258 | ||
| 259 | ||
| 260 | /* Warning! This trace code is a virtual duplicate of the code above so be | |
| 261 | * sure to maintain both! */ | |
| 262 | .Ltracesys: | |
| 263 | tracesys: | |
| 264 | /* Need to save more registers so the debugger can see where we | |
| 265 | * are. This saves only the lower 8 bits of PSW, so that the C | |
| 266 | * bit is still clear on syscalls, and the D bit is set if this | |
| 267 | * full register save path has been executed. We check the D | |
| 268 | * bit on syscall_return_rfi to determine which registers to | |
| 269 | * restore. An interrupt results in a full PSW saved with the | |
| 270 | * C bit set, a non-straced syscall entry results in C and D clear | |
| 271 | * in the saved PSW. | |
| 272 | */ | |
| 273 | ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ | |
| 274 | LDREG TI_TASK(%r1), %r1 | |
| 275 | ssm 0,%r2 | |
| 276 | STREG %r2,TASK_PT_PSW(%r1) /* Lower 8 bits only!! */ | |
| 277 | mfsp %sr0,%r2 | |
| 278 | STREG %r2,TASK_PT_SR0(%r1) | |
| 279 | mfsp %sr1,%r2 | |
| 280 | STREG %r2,TASK_PT_SR1(%r1) | |
| 281 | mfsp %sr2,%r2 | |
| 282 | STREG %r2,TASK_PT_SR2(%r1) | |
| 283 | mfsp %sr3,%r2 | |
| 284 | STREG %r2,TASK_PT_SR3(%r1) | |
| 285 | STREG %r2,TASK_PT_SR4(%r1) | |
| 286 | STREG %r2,TASK_PT_SR5(%r1) | |
| 287 | STREG %r2,TASK_PT_SR6(%r1) | |
| 288 | STREG %r2,TASK_PT_SR7(%r1) | |
| 289 | STREG %r2,TASK_PT_IASQ0(%r1) | |
| 290 | STREG %r2,TASK_PT_IASQ1(%r1) | |
| 291 | LDREG TASK_PT_GR31(%r1),%r2 | |
| 292 | STREG %r2,TASK_PT_IAOQ0(%r1) | |
| 293 | ldo 4(%r2),%r2 | |
| 294 | STREG %r2,TASK_PT_IAOQ1(%r1) | |
| 295 | ldo TASK_REGS(%r1),%r2 | |
| 296 | /* reg_save %r2 */ | |
| 297 | STREG %r3,PT_GR3(%r2) | |
| 298 | STREG %r4,PT_GR4(%r2) | |
| 299 | STREG %r5,PT_GR5(%r2) | |
| 300 | STREG %r6,PT_GR6(%r2) | |
| 301 | STREG %r7,PT_GR7(%r2) | |
| 302 | STREG %r8,PT_GR8(%r2) | |
| 303 | STREG %r9,PT_GR9(%r2) | |
| 304 | STREG %r10,PT_GR10(%r2) | |
| 305 | STREG %r11,PT_GR11(%r2) | |
| 306 | STREG %r12,PT_GR12(%r2) | |
| 307 | STREG %r13,PT_GR13(%r2) | |
| 308 | STREG %r14,PT_GR14(%r2) | |
| 309 | STREG %r15,PT_GR15(%r2) | |
| 310 | STREG %r16,PT_GR16(%r2) | |
| 311 | STREG %r17,PT_GR17(%r2) | |
| 312 | STREG %r18,PT_GR18(%r2) | |
| 313 | /* Finished saving things for the debugger */ | |
| 314 | ||
| 2798af1a KM |
315 | copy %r2,%r26 |
| 316 | ldil L%do_syscall_trace_enter,%r1 | |
| 1da177e4 | 317 | ldil L%tracesys_next,%r2 |
| 2798af1a | 318 | be R%do_syscall_trace_enter(%sr7,%r1) |
| 1da177e4 LT |
319 | ldo R%tracesys_next(%r2),%r2 |
| 320 | ||
| 2798af1a KM |
321 | tracesys_next: |
| 322 | /* do_syscall_trace_enter either returned the syscallno, or -1L, | |
| 323 | * so we skip restoring the PT_GR20 below, since we pulled it from | |
| 324 | * task->thread.regs.gr[20] above. | |
| 325 | */ | |
| 326 | copy %ret0,%r20 | |
| 1da177e4 LT |
327 | ldil L%sys_call_table,%r1 |
| 328 | ldo R%sys_call_table(%r1), %r19 | |
| 329 | ||
| 330 | ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ | |
| 331 | LDREG TI_TASK(%r1), %r1 | |
| 1da177e4 LT |
332 | LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */ |
| 333 | LDREG TASK_PT_GR25(%r1), %r25 | |
| 334 | LDREG TASK_PT_GR24(%r1), %r24 | |
| 335 | LDREG TASK_PT_GR23(%r1), %r23 | |
| 1da177e4 LT |
336 | LDREG TASK_PT_GR22(%r1), %r22 |
| 337 | LDREG TASK_PT_GR21(%r1), %r21 | |
| 52ab532e | 338 | #ifdef CONFIG_64BIT |
| 1da177e4 | 339 | ldo -16(%r30),%r29 /* Reference param save area */ |
| 52ab532e AV |
340 | #else |
| 341 | stw %r22, -52(%r30) /* 5th argument */ | |
| 342 | stw %r21, -56(%r30) /* 6th argument */ | |
| 1da177e4 LT |
343 | #endif |
| 344 | ||
| 345 | comiclr,>>= __NR_Linux_syscalls, %r20, %r0 | |
| 98e8b6c9 | 346 | b,n .Ltracesys_nosys |
| 1da177e4 LT |
347 | |
| 348 | LDREGX %r20(%r19), %r19 | |
| 349 | ||
| 350 | /* If this is a sys_rt_sigreturn call, and the signal was received | |
| 351 | * when not in_syscall, then we want to return via syscall_exit_rfi, | |
| 352 | * not syscall_exit. Signal no. in r20, in_syscall in r25 (see | |
| 353 | * trampoline code in signal.c). | |
| 354 | */ | |
| 355 | ldi __NR_rt_sigreturn,%r2 | |
| 356 | comb,= %r2,%r20,.Ltrace_rt_sigreturn | |
| 357 | .Ltrace_in_syscall: | |
| 358 | ldil L%tracesys_exit,%r2 | |
| 359 | be 0(%sr7,%r19) | |
| 360 | ldo R%tracesys_exit(%r2),%r2 | |
| 361 | ||
| 98e8b6c9 HD |
362 | .Ltracesys_nosys: |
| 363 | ldo -ENOSYS(%r0),%r28 /* set errno */ | |
| 364 | ||
| 1da177e4 LT |
365 | /* Do *not* call this function on the gateway page, because it |
| 366 | makes a direct call to syscall_trace. */ | |
| 367 | ||
| 368 | tracesys_exit: | |
| 369 | ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ | |
| 370 | LDREG TI_TASK(%r1), %r1 | |
| 413059f2 | 371 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
372 | ldo -16(%r30),%r29 /* Reference param save area */ |
| 373 | #endif | |
| 2798af1a | 374 | ldo TASK_REGS(%r1),%r26 |
| 337685e5 | 375 | BL do_syscall_trace_exit,%r2 |
| 1da177e4 LT |
376 | STREG %r28,TASK_PT_GR28(%r1) /* save return value now */ |
| 377 | ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ | |
| 378 | LDREG TI_TASK(%r1), %r1 | |
| 379 | LDREG TASK_PT_GR28(%r1), %r28 /* Restore return val. */ | |
| 380 | ||
| 381 | ldil L%syscall_exit,%r1 | |
| 382 | be,n R%syscall_exit(%sr7,%r1) | |
| 383 | ||
| 384 | .Ltrace_rt_sigreturn: | |
| 385 | comib,<> 0,%r25,.Ltrace_in_syscall | |
| 386 | ldil L%tracesys_sigexit,%r2 | |
| 387 | be 0(%sr7,%r19) | |
| 388 | ldo R%tracesys_sigexit(%r2),%r2 | |
| 389 | ||
| 390 | tracesys_sigexit: | |
| 391 | ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ | |
| 5837d42f | 392 | LDREG TI_TASK(%r1), %r1 |
| 413059f2 | 393 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
394 | ldo -16(%r30),%r29 /* Reference param save area */ |
| 395 | #endif | |
| 337685e5 | 396 | BL do_syscall_trace_exit,%r2 |
| 2798af1a | 397 | ldo TASK_REGS(%r1),%r26 |
| 1da177e4 LT |
398 | |
| 399 | ldil L%syscall_exit_rfi,%r1 | |
| 400 | be,n R%syscall_exit_rfi(%sr7,%r1) | |
| 401 | ||
| 402 | ||
| 403 | /********************************************************* | |
| c84c3a69 | 404 | 32/64-bit Light-Weight-Syscall ABI |
| 1da177e4 | 405 | |
| c84c3a69 HD |
406 | * - Indicates a hint for userspace inline asm |
| 407 | implementations. | |
| 1da177e4 | 408 | |
| c84c3a69 HD |
409 | Syscall number (caller-saves) |
| 410 | - %r20 | |
| 411 | * In asm clobber. | |
| 1da177e4 | 412 | |
| c84c3a69 HD |
413 | Argument registers (caller-saves) |
| 414 | - %r26, %r25, %r24, %r23, %r22 | |
| 415 | * In asm input. | |
| 416 | ||
| 417 | Return registers (caller-saves) | |
| 418 | - %r28 (return), %r21 (errno) | |
| 419 | * In asm output. | |
| 420 | ||
| 421 | Caller-saves registers | |
| 422 | - %r1, %r27, %r29 | |
| 423 | - %r2 (return pointer) | |
| 424 | - %r31 (ble link register) | |
| 425 | * In asm clobber. | |
| 426 | ||
| 427 | Callee-saves registers | |
| 428 | - %r3-%r18 | |
| 429 | - %r30 (stack pointer) | |
| 430 | * Not in asm clobber. | |
| 431 | ||
| 432 | If userspace is 32-bit: | |
| 433 | Callee-saves registers | |
| 434 | - %r19 (32-bit PIC register) | |
| 435 | ||
| 436 | Differences from 32-bit calling convention: | |
| 437 | - Syscall number in %r20 | |
| 438 | - Additional argument register %r22 (arg4) | |
| 439 | - Callee-saves %r19. | |
| 440 | ||
| 441 | If userspace is 64-bit: | |
| 442 | Callee-saves registers | |
| 443 | - %r27 (64-bit PIC register) | |
| 444 | ||
| 445 | Differences from 64-bit calling convention: | |
| 446 | - Syscall number in %r20 | |
| 447 | - Additional argument register %r22 (arg4) | |
| 448 | - Callee-saves %r27. | |
| 1da177e4 LT |
449 | |
| 450 | Error codes returned by entry path: | |
| 451 | ||
| 452 | ENOSYS - r20 was an invalid LWS number. | |
| 453 | ||
| 454 | *********************************************************/ | |
| 455 | lws_start: | |
| 1da177e4 | 456 | |
| 413059f2 | 457 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
458 | /* FIXME: If we are a 64-bit kernel just |
| 459 | * turn this on unconditionally. | |
| 460 | */ | |
| 461 | ssm PSW_SM_W, %r1 | |
| 462 | extrd,u %r1,PSW_W_BIT,1,%r1 | |
| 463 | /* sp must be aligned on 4, so deposit the W bit setting into | |
| 464 | * the bottom of sp temporarily */ | |
| 465 | or,ev %r1,%r30,%r30 | |
| 466 | ||
| 467 | /* Clip LWS number to a 32-bit value always */ | |
| 468 | depdi 0, 31, 32, %r20 | |
| 469 | #endif | |
| 470 | ||
| 471 | /* Is the lws entry number valid? */ | |
| f4c0346c | 472 | comiclr,>> __NR_lws_entries, %r20, %r0 |
| 1da177e4 LT |
473 | b,n lws_exit_nosys |
| 474 | ||
| 475 | /* WARNING: Trashing sr2 and sr3 */ | |
| 476 | mfsp %sr7,%r1 /* get userspace into sr3 */ | |
| 477 | mtsp %r1,%sr3 | |
| 478 | mtsp %r0,%sr2 /* get kernel space into sr2 */ | |
| 479 | ||
| 480 | /* Load table start */ | |
| 481 | ldil L%lws_table, %r1 | |
| 482 | ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */ | |
| 483 | LDREGX %r20(%sr2,r28), %r21 /* Scratch use of r21 */ | |
| 484 | ||
| 485 | /* Jump to lws, lws table pointers already relocated */ | |
| 486 | be,n 0(%sr2,%r21) | |
| 487 | ||
| 488 | lws_exit_nosys: | |
| 489 | ldo -ENOSYS(%r0),%r21 /* set errno */ | |
| 490 | /* Fall through: Return to userspace */ | |
| 491 | ||
| 492 | lws_exit: | |
| 413059f2 | 493 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
494 | /* decide whether to reset the wide mode bit |
| 495 | * | |
| 496 | * For a syscall, the W bit is stored in the lowest bit | |
| 497 | * of sp. Extract it and reset W if it is zero */ | |
| 498 | extrd,u,*<> %r30,63,1,%r1 | |
| 499 | rsm PSW_SM_W, %r0 | |
| 500 | /* now reset the lowest bit of sp if it was set */ | |
| 501 | xor %r30,%r1,%r30 | |
| 502 | #endif | |
| f4c0346c | 503 | be,n 0(%sr7, %r31) |
| 1da177e4 LT |
504 | |
| 505 | ||
| 506 | ||
| 507 | /*************************************************** | |
| 89206491 | 508 | Implementing 32bit CAS as an atomic operation: |
| 1da177e4 LT |
509 | |
| 510 | %r26 - Address to examine | |
| 511 | %r25 - Old value to check (old) | |
| 512 | %r24 - New value to set (new) | |
| 513 | %r28 - Return prev through this register. | |
| 514 | %r21 - Kernel error code | |
| 515 | ||
| 516 | If debugging is DISabled: | |
| 517 | ||
| 518 | %r21 has the following meanings: | |
| 519 | ||
| 520 | EAGAIN - CAS is busy, ldcw failed, try again. | |
| 521 | EFAULT - Read or write failed. | |
| 522 | ||
| 523 | If debugging is enabled: | |
| 524 | ||
| 525 | EDEADLOCK - CAS called recursively. | |
| 526 | EAGAIN && r28 == 1 - CAS is busy. Lock contended. | |
| 527 | EAGAIN && r28 == 2 - CAS is busy. ldcw failed. | |
| 528 | EFAULT - Read or write failed. | |
| 529 | ||
| 530 | Scratch: r20, r28, r1 | |
| 531 | ||
| 532 | ****************************************************/ | |
| 533 | ||
| 534 | /* Do not enable LWS debugging */ | |
| 535 | #define ENABLE_LWS_DEBUG 0 | |
| 536 | ||
| 537 | /* ELF64 Process entry path */ | |
| 538 | lws_compare_and_swap64: | |
| 413059f2 | 539 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
540 | b,n lws_compare_and_swap |
| 541 | #else | |
| 542 | /* If we are not a 64-bit kernel, then we don't | |
| c84c3a69 HD |
543 | * have 64-bit input registers, and calling |
| 544 | * the 64-bit LWS CAS returns ENOSYS. | |
| 1da177e4 LT |
545 | */ |
| 546 | b,n lws_exit_nosys | |
| 547 | #endif | |
| 548 | ||
| 549 | /* ELF32 Process entry path */ | |
| 550 | lws_compare_and_swap32: | |
| 413059f2 | 551 | #ifdef CONFIG_64BIT |
| 1da177e4 LT |
552 | /* Clip all the input registers */ |
| 553 | depdi 0, 31, 32, %r26 | |
| 554 | depdi 0, 31, 32, %r25 | |
| 555 | depdi 0, 31, 32, %r24 | |
| 556 | #endif | |
| 557 | ||
| 558 | lws_compare_and_swap: | |
| 1da177e4 LT |
559 | /* Load start of lock table */ |
| 560 | ldil L%lws_lock_start, %r20 | |
| 561 | ldo R%lws_lock_start(%r20), %r28 | |
| 562 | ||
| 563 | /* Extract four bits from r26 and hash lock (Bits 4-7) */ | |
| 564 | extru %r26, 27, 4, %r20 | |
| 565 | ||
| 566 | /* Find lock to use, the hash is either one of 0 to | |
| 567 | 15, multiplied by 16 (keep it 16-byte aligned) | |
| 568 | and add to the lock table offset. */ | |
| 569 | shlw %r20, 4, %r20 | |
| 570 | add %r20, %r28, %r20 | |
| 571 | ||
| b5e8b733 | 572 | # if ENABLE_LWS_DEBUG |
| 1da177e4 LT |
573 | /* |
| 574 | DEBUG, check for deadlock! | |
| 575 | If the thread register values are the same | |
| 576 | then we were the one that locked it last and | |
| 577 | this is a recurisve call that will deadlock. | |
| 578 | We *must* giveup this call and fail. | |
| 579 | */ | |
| 580 | ldw 4(%sr2,%r20), %r28 /* Load thread register */ | |
| aa0eecb0 | 581 | /* WARNING: If cr27 cycles to the same value we have problems */ |
| 1da177e4 LT |
582 | mfctl %cr27, %r21 /* Get current thread register */ |
| 583 | cmpb,<>,n %r21, %r28, cas_lock /* Called recursive? */ | |
| 584 | b lws_exit /* Return error! */ | |
| 585 | ldo -EDEADLOCK(%r0), %r21 | |
| 586 | cas_lock: | |
| 587 | cmpb,=,n %r0, %r28, cas_nocontend /* Is nobody using it? */ | |
| 588 | ldo 1(%r0), %r28 /* 1st case */ | |
| 589 | b lws_exit /* Contended... */ | |
| 590 | ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ | |
| 591 | cas_nocontend: | |
| 592 | # endif | |
| 593 | /* ENABLE_LWS_DEBUG */ | |
| 594 | ||
| c776cd89 JDA |
595 | rsm PSW_SM_I, %r0 /* Disable interrupts */ |
| 596 | /* COW breaks can cause contention on UP systems */ | |
| 64f49532 | 597 | LDCW 0(%sr2,%r20), %r28 /* Try to acquire the lock */ |
| 1da177e4 LT |
598 | cmpb,<>,n %r0, %r28, cas_action /* Did we get it? */ |
| 599 | cas_wouldblock: | |
| 600 | ldo 2(%r0), %r28 /* 2nd case */ | |
| c776cd89 | 601 | ssm PSW_SM_I, %r0 |
| 1da177e4 LT |
602 | b lws_exit /* Contended... */ |
| 603 | ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ | |
| 1da177e4 LT |
604 | |
| 605 | /* | |
| 606 | prev = *addr; | |
| 607 | if ( prev == old ) | |
| 608 | *addr = new; | |
| 609 | return prev; | |
| 610 | */ | |
| 611 | ||
| 612 | /* NOTES: | |
| 613 | This all works becuse intr_do_signal | |
| 614 | and schedule both check the return iasq | |
| 615 | and see that we are on the kernel page | |
| 616 | so this process is never scheduled off | |
| 617 | or is ever sent any signal of any sort, | |
| 618 | thus it is wholly atomic from usrspaces | |
| 619 | perspective | |
| 620 | */ | |
| 621 | cas_action: | |
| b5e8b733 | 622 | #if defined CONFIG_SMP && ENABLE_LWS_DEBUG |
| 1da177e4 LT |
623 | /* DEBUG */ |
| 624 | mfctl %cr27, %r1 | |
| 625 | stw %r1, 4(%sr2,%r20) | |
| 626 | #endif | |
| 627 | /* The load and store could fail */ | |
| c776cd89 | 628 | 1: ldw,ma 0(%sr3,%r26), %r28 |
| 1da177e4 | 629 | sub,<> %r28, %r25, %r0 |
| c776cd89 | 630 | 2: stw,ma %r24, 0(%sr3,%r26) |
| 1da177e4 | 631 | /* Free lock */ |
| c776cd89 | 632 | stw,ma %r20, 0(%sr2,%r20) |
| f4c0346c | 633 | #if ENABLE_LWS_DEBUG |
| 1da177e4 LT |
634 | /* Clear thread register indicator */ |
| 635 | stw %r0, 4(%sr2,%r20) | |
| 1da177e4 | 636 | #endif |
| c776cd89 JDA |
637 | /* Enable interrupts */ |
| 638 | ssm PSW_SM_I, %r0 | |
| 1da177e4 LT |
639 | /* Return to userspace, set no error */ |
| 640 | b lws_exit | |
| 641 | copy %r0, %r21 | |
| 642 | ||
| 643 | 3: | |
| 25985edc | 644 | /* Error occurred on load or store */ |
| 1da177e4 LT |
645 | /* Free lock */ |
| 646 | stw %r20, 0(%sr2,%r20) | |
| f4c0346c | 647 | #if ENABLE_LWS_DEBUG |
| 1da177e4 | 648 | stw %r0, 4(%sr2,%r20) |
| 1da177e4 | 649 | #endif |
| c776cd89 | 650 | ssm PSW_SM_I, %r0 |
| 1da177e4 LT |
651 | b lws_exit |
| 652 | ldo -EFAULT(%r0),%r21 /* set errno */ | |
| 653 | nop | |
| 654 | nop | |
| 655 | nop | |
| 656 | nop | |
| 657 | ||
| 658 | /* Two exception table entries, one for the load, | |
| 659 | the other for the store. Either return -EFAULT. | |
| 660 | Each of the entries must be relocated. */ | |
| 61dbbaeb HD |
661 | ASM_EXCEPTIONTABLE_ENTRY(1b-linux_gateway_page, 3b-linux_gateway_page) |
| 662 | ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 3b-linux_gateway_page) | |
| 1da177e4 | 663 | |
| 1da177e4 | 664 | |
| 89206491 GM |
665 | /*************************************************** |
| 666 | New CAS implementation which uses pointers and variable size | |
| 667 | information. The value pointed by old and new MUST NOT change | |
| 668 | while performing CAS. The lock only protect the value at %r26. | |
| 669 | ||
| 670 | %r26 - Address to examine | |
| 671 | %r25 - Pointer to the value to check (old) | |
| 672 | %r24 - Pointer to the value to set (new) | |
| 673 | %r23 - Size of the variable (0/1/2/3 for 8/16/32/64 bit) | |
| 674 | %r28 - Return non-zero on failure | |
| 675 | %r21 - Kernel error code | |
| 676 | ||
| 677 | %r21 has the following meanings: | |
| 678 | ||
| 679 | EAGAIN - CAS is busy, ldcw failed, try again. | |
| 680 | EFAULT - Read or write failed. | |
| 681 | ||
| 682 | Scratch: r20, r22, r28, r29, r1, fr4 (32bit for 64bit CAS only) | |
| 683 | ||
| 684 | ****************************************************/ | |
| 685 | ||
| 686 | /* ELF32 Process entry path */ | |
| 687 | lws_compare_and_swap_2: | |
| 688 | #ifdef CONFIG_64BIT | |
| 689 | /* Clip the input registers */ | |
| 690 | depdi 0, 31, 32, %r26 | |
| 691 | depdi 0, 31, 32, %r25 | |
| 692 | depdi 0, 31, 32, %r24 | |
| 693 | depdi 0, 31, 32, %r23 | |
| 694 | #endif | |
| 695 | ||
| 696 | /* Check the validity of the size pointer */ | |
| 697 | subi,>>= 4, %r23, %r0 | |
| 698 | b,n lws_exit_nosys | |
| 699 | ||
| 700 | /* Jump to the functions which will load the old and new values into | |
| 701 | registers depending on the their size */ | |
| 702 | shlw %r23, 2, %r29 | |
| 703 | blr %r29, %r0 | |
| 704 | nop | |
| 705 | ||
| 706 | /* 8bit load */ | |
| 707 | 4: ldb 0(%sr3,%r25), %r25 | |
| 708 | b cas2_lock_start | |
| 709 | 5: ldb 0(%sr3,%r24), %r24 | |
| 710 | nop | |
| 711 | nop | |
| 712 | nop | |
| 713 | nop | |
| 714 | nop | |
| 715 | ||
| 716 | /* 16bit load */ | |
| 717 | 6: ldh 0(%sr3,%r25), %r25 | |
| 718 | b cas2_lock_start | |
| 719 | 7: ldh 0(%sr3,%r24), %r24 | |
| 720 | nop | |
| 721 | nop | |
| 722 | nop | |
| 723 | nop | |
| 724 | nop | |
| 725 | ||
| 726 | /* 32bit load */ | |
| 727 | 8: ldw 0(%sr3,%r25), %r25 | |
| 728 | b cas2_lock_start | |
| 729 | 9: ldw 0(%sr3,%r24), %r24 | |
| 730 | nop | |
| 731 | nop | |
| 732 | nop | |
| 733 | nop | |
| 734 | nop | |
| 735 | ||
| 736 | /* 64bit load */ | |
| 737 | #ifdef CONFIG_64BIT | |
| 738 | 10: ldd 0(%sr3,%r25), %r25 | |
| 739 | 11: ldd 0(%sr3,%r24), %r24 | |
| 740 | #else | |
| 741 | /* Load new value into r22/r23 - high/low */ | |
| 742 | 10: ldw 0(%sr3,%r25), %r22 | |
| 743 | 11: ldw 4(%sr3,%r25), %r23 | |
| 744 | /* Load new value into fr4 for atomic store later */ | |
| 745 | 12: flddx 0(%sr3,%r24), %fr4 | |
| 746 | #endif | |
| 747 | ||
| 748 | cas2_lock_start: | |
| 749 | /* Load start of lock table */ | |
| 750 | ldil L%lws_lock_start, %r20 | |
| 751 | ldo R%lws_lock_start(%r20), %r28 | |
| 752 | ||
| 753 | /* Extract four bits from r26 and hash lock (Bits 4-7) */ | |
| 754 | extru %r26, 27, 4, %r20 | |
| 755 | ||
| 756 | /* Find lock to use, the hash is either one of 0 to | |
| 757 | 15, multiplied by 16 (keep it 16-byte aligned) | |
| 758 | and add to the lock table offset. */ | |
| 759 | shlw %r20, 4, %r20 | |
| 760 | add %r20, %r28, %r20 | |
| 761 | ||
| 762 | rsm PSW_SM_I, %r0 /* Disable interrupts */ | |
| 763 | /* COW breaks can cause contention on UP systems */ | |
| 764 | LDCW 0(%sr2,%r20), %r28 /* Try to acquire the lock */ | |
| 765 | cmpb,<>,n %r0, %r28, cas2_action /* Did we get it? */ | |
| 766 | cas2_wouldblock: | |
| 767 | ldo 2(%r0), %r28 /* 2nd case */ | |
| 768 | ssm PSW_SM_I, %r0 | |
| 769 | b lws_exit /* Contended... */ | |
| 770 | ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ | |
| 771 | ||
| 772 | /* | |
| 773 | prev = *addr; | |
| 774 | if ( prev == old ) | |
| 775 | *addr = new; | |
| 776 | return prev; | |
| 777 | */ | |
| 778 | ||
| 779 | /* NOTES: | |
| 780 | This all works becuse intr_do_signal | |
| 781 | and schedule both check the return iasq | |
| 782 | and see that we are on the kernel page | |
| 783 | so this process is never scheduled off | |
| 784 | or is ever sent any signal of any sort, | |
| 785 | thus it is wholly atomic from usrspaces | |
| 786 | perspective | |
| 787 | */ | |
| 788 | cas2_action: | |
| 789 | /* Jump to the correct function */ | |
| 790 | blr %r29, %r0 | |
| 791 | /* Set %r28 as non-zero for now */ | |
| 792 | ldo 1(%r0),%r28 | |
| 793 | ||
| 794 | /* 8bit CAS */ | |
| 795 | 13: ldb,ma 0(%sr3,%r26), %r29 | |
| 796 | sub,= %r29, %r25, %r0 | |
| 797 | b,n cas2_end | |
| 798 | 14: stb,ma %r24, 0(%sr3,%r26) | |
| 799 | b cas2_end | |
| 800 | copy %r0, %r28 | |
| 801 | nop | |
| 802 | nop | |
| 803 | ||
| 804 | /* 16bit CAS */ | |
| 805 | 15: ldh,ma 0(%sr3,%r26), %r29 | |
| 806 | sub,= %r29, %r25, %r0 | |
| 807 | b,n cas2_end | |
| 808 | 16: sth,ma %r24, 0(%sr3,%r26) | |
| 809 | b cas2_end | |
| 810 | copy %r0, %r28 | |
| 811 | nop | |
| 812 | nop | |
| 813 | ||
| 814 | /* 32bit CAS */ | |
| 815 | 17: ldw,ma 0(%sr3,%r26), %r29 | |
| 816 | sub,= %r29, %r25, %r0 | |
| 817 | b,n cas2_end | |
| 818 | 18: stw,ma %r24, 0(%sr3,%r26) | |
| 819 | b cas2_end | |
| 820 | copy %r0, %r28 | |
| 821 | nop | |
| 822 | nop | |
| 823 | ||
| 824 | /* 64bit CAS */ | |
| 825 | #ifdef CONFIG_64BIT | |
| 826 | 19: ldd,ma 0(%sr3,%r26), %r29 | |
| 1b59ddfc | 827 | sub,*= %r29, %r25, %r0 |
| 89206491 GM |
828 | b,n cas2_end |
| 829 | 20: std,ma %r24, 0(%sr3,%r26) | |
| 830 | copy %r0, %r28 | |
| 831 | #else | |
| 832 | /* Compare first word */ | |
| 833 | 19: ldw,ma 0(%sr3,%r26), %r29 | |
| 834 | sub,= %r29, %r22, %r0 | |
| 835 | b,n cas2_end | |
| 836 | /* Compare second word */ | |
| 837 | 20: ldw,ma 4(%sr3,%r26), %r29 | |
| 838 | sub,= %r29, %r23, %r0 | |
| 839 | b,n cas2_end | |
| 840 | /* Perform the store */ | |
| 841 | 21: fstdx %fr4, 0(%sr3,%r26) | |
| 842 | copy %r0, %r28 | |
| 843 | #endif | |
| 844 | ||
| 845 | cas2_end: | |
| 846 | /* Free lock */ | |
| 847 | stw,ma %r20, 0(%sr2,%r20) | |
| 848 | /* Enable interrupts */ | |
| 849 | ssm PSW_SM_I, %r0 | |
| 850 | /* Return to userspace, set no error */ | |
| 851 | b lws_exit | |
| 852 | copy %r0, %r21 | |
| 853 | ||
| 854 | 22: | |
| 855 | /* Error occurred on load or store */ | |
| 856 | /* Free lock */ | |
| 857 | stw %r20, 0(%sr2,%r20) | |
| 858 | ssm PSW_SM_I, %r0 | |
| 859 | ldo 1(%r0),%r28 | |
| 860 | b lws_exit | |
| 861 | ldo -EFAULT(%r0),%r21 /* set errno */ | |
| 862 | nop | |
| 863 | nop | |
| 864 | nop | |
| 865 | ||
| 866 | /* Exception table entries, for the load and store, return EFAULT. | |
| 867 | Each of the entries must be relocated. */ | |
| 868 | ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 22b-linux_gateway_page) | |
| 869 | ASM_EXCEPTIONTABLE_ENTRY(5b-linux_gateway_page, 22b-linux_gateway_page) | |
| 870 | ASM_EXCEPTIONTABLE_ENTRY(6b-linux_gateway_page, 22b-linux_gateway_page) | |
| 871 | ASM_EXCEPTIONTABLE_ENTRY(7b-linux_gateway_page, 22b-linux_gateway_page) | |
| 872 | ASM_EXCEPTIONTABLE_ENTRY(8b-linux_gateway_page, 22b-linux_gateway_page) | |
| 873 | ASM_EXCEPTIONTABLE_ENTRY(9b-linux_gateway_page, 22b-linux_gateway_page) | |
| 874 | ASM_EXCEPTIONTABLE_ENTRY(10b-linux_gateway_page, 22b-linux_gateway_page) | |
| 875 | ASM_EXCEPTIONTABLE_ENTRY(11b-linux_gateway_page, 22b-linux_gateway_page) | |
| 876 | ASM_EXCEPTIONTABLE_ENTRY(13b-linux_gateway_page, 22b-linux_gateway_page) | |
| 877 | ASM_EXCEPTIONTABLE_ENTRY(14b-linux_gateway_page, 22b-linux_gateway_page) | |
| 878 | ASM_EXCEPTIONTABLE_ENTRY(15b-linux_gateway_page, 22b-linux_gateway_page) | |
| 879 | ASM_EXCEPTIONTABLE_ENTRY(16b-linux_gateway_page, 22b-linux_gateway_page) | |
| 880 | ASM_EXCEPTIONTABLE_ENTRY(17b-linux_gateway_page, 22b-linux_gateway_page) | |
| 881 | ASM_EXCEPTIONTABLE_ENTRY(18b-linux_gateway_page, 22b-linux_gateway_page) | |
| 882 | ASM_EXCEPTIONTABLE_ENTRY(19b-linux_gateway_page, 22b-linux_gateway_page) | |
| 883 | ASM_EXCEPTIONTABLE_ENTRY(20b-linux_gateway_page, 22b-linux_gateway_page) | |
| 884 | #ifndef CONFIG_64BIT | |
| 885 | ASM_EXCEPTIONTABLE_ENTRY(12b-linux_gateway_page, 22b-linux_gateway_page) | |
| 886 | ASM_EXCEPTIONTABLE_ENTRY(21b-linux_gateway_page, 22b-linux_gateway_page) | |
| 887 | #endif | |
| 888 | ||
| 1da177e4 | 889 | /* Make sure nothing else is placed on this page */ |
| 1c593571 | 890 | .align PAGE_SIZE |
| 8e9e9844 HD |
891 | END(linux_gateway_page) |
| 892 | ENTRY(end_linux_gateway_page) | |
| 1da177e4 LT |
893 | |
| 894 | /* Relocate symbols assuming linux_gateway_page is mapped | |
| 895 | to virtual address 0x0 */ | |
| 8e9e9844 | 896 | |
| 0b3d643f | 897 | #define LWS_ENTRY(_name_) ASM_ULONG_INSN (lws_##_name_ - linux_gateway_page) |
| 1da177e4 | 898 | |
| 1bcdd854 HD |
899 | .section .rodata,"a" |
| 900 | ||
| 6a45716a | 901 | .align 8 |
| 1da177e4 LT |
902 | /* Light-weight-syscall table */ |
| 903 | /* Start of lws table. */ | |
| 8e9e9844 | 904 | ENTRY(lws_table) |
| 89206491 GM |
905 | LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic 32bit CAS */ |
| 906 | LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic 32bit CAS */ | |
| 907 | LWS_ENTRY(compare_and_swap_2) /* 2 - ELF32 Atomic 64bit CAS */ | |
| 8e9e9844 | 908 | END(lws_table) |
| 1da177e4 LT |
909 | /* End of lws table */ |
| 910 | ||
| 6a45716a | 911 | .align 8 |
| 8e9e9844 | 912 | ENTRY(sys_call_table) |
| 1da177e4 | 913 | #include "syscall_table.S" |
| 8e9e9844 | 914 | END(sys_call_table) |
| 1da177e4 | 915 | |
| 413059f2 | 916 | #ifdef CONFIG_64BIT |
| 6a45716a | 917 | .align 8 |
| 8e9e9844 | 918 | ENTRY(sys_call_table64) |
| 1da177e4 LT |
919 | #define SYSCALL_TABLE_64BIT |
| 920 | #include "syscall_table.S" | |
| 8e9e9844 | 921 | END(sys_call_table64) |
| 1da177e4 LT |
922 | #endif |
| 923 | ||
| 1da177e4 LT |
924 | /* |
| 925 | All light-weight-syscall atomic operations | |
| 926 | will use this set of locks | |
| c84c3a69 HD |
927 | |
| 928 | NOTE: The lws_lock_start symbol must be | |
| 929 | at least 16-byte aligned for safe use | |
| 930 | with ldcw. | |
| 1da177e4 | 931 | */ |
| dfcf753b | 932 | .section .data |
| 6a45716a | 933 | .align L1_CACHE_BYTES |
| 8e9e9844 | 934 | ENTRY(lws_lock_start) |
| 1da177e4 | 935 | /* lws locks */ |
| 1da177e4 LT |
936 | .rept 16 |
| 937 | /* Keep locks aligned at 16-bytes */ | |
| 938 | .word 1 | |
| 939 | .word 0 | |
| 940 | .word 0 | |
| 941 | .word 0 | |
| 942 | .endr | |
| 8e9e9844 | 943 | END(lws_lock_start) |
| 1da177e4 | 944 | .previous |
| 1da177e4 LT |
945 | |
| 946 | .end | |
| 947 | ||
| 948 |