sn1_brand_asm.s revision 7933:6a8cc62fe2a1
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26#if defined(lint) 27 28#include <sys/systm.h> 29 30void 31sn1_brand_syscall32_callback(void) 32{ 33} 34 35void 36sn1_brand_syscall_callback(void) 37{ 38} 39 40#else /* !lint */ 41 42#include <sys/asm_linkage.h> 43#include <sys/machthread.h> 44#include <sys/privregs.h> 45#include <sn1_offsets.h> 46#include "assym.h" 47 48#if defined(sun4v) 49 50#define GLOBALS_SWAP(reg) \ 51 rdpr %gl, reg ;\ 52 wrpr reg, 1, %gl 53 54/* 55 * The GLOBALS_RESTORE macro can only be one instruction since it's 56 * used in a delay slot. 57 */ 58#define GLOBALS_RESTORE(reg) \ 59 wrpr reg, 0, %gl 60 61#else /* !sun4v */ 62 63#define GLOBALS_SWAP(reg) \ 64 rdpr %pstate, reg ;\ 65 wrpr reg, PSTATE_AG, %pstate 66 67/* 68 * The GLOBALS_RESTORE macro can only be one instruction since it's 69 * used in a delay slot. 70 */ 71#define GLOBALS_RESTORE(reg) \ 72 wrpr reg, %g0, %pstate 73 74#endif /* !sun4v */ 75 76 /* 77 * Input parameters: 78 * %g1: return point 79 * %g2: pointer to our cpu structure 80 */ 81 ENTRY(sn1_brand_syscall32_callback) 82 /* 83 * If the trapping thread has the address mask bit clear, then it's 84 * a 64-bit process, and has no business calling 32-bit syscalls. 85 */ 86 rdpr %tstate, %g3 ! %tstate.am is the trapping 87 andcc %g3, TSTATE_AM, %g3 ! threads address mask bit 88 bne,pt %xcc, _entry 89 nop 90 jmp %g1 ! 64 bit process, bail out 91 nop 92 SET_SIZE(sn1_brand_syscall32_callback) 93 94 /* 95 * Input parameters: 96 * %g1: return point 97 * %g2: pointer to our cpu structure 98 */ 99 ENTRY(sn1_brand_syscall_callback) 100 /* 101 * If the trapping thread has the address mask bit set, then it's 102 * a 32-bit process, and has no business calling 64-bit syscalls. 103 */ 104 rdpr %tstate, %g3 ! %tstate.am is the trapping 105 andcc %g3, TSTATE_AM, %g3 ! threads address mask bit 106 be,pt %xcc, _entry 107 nop 108 jmp %g1 ! 32 bit process, bail out 109 nop 110 SET_SIZE(sn1_brand_syscall_callback) 111 112 ENTRY(sn1_brand_syscall_callback_common) 113_entry: 114 /* 115 * Input parameters: 116 * %g1: return point 117 * %g2: pointer to our cpu structure 118 * 119 * Note that we're free to use any %g? registers as long as 120 * we are are executing with alternate globals. If we're 121 * executing with user globals we need to backup any registers 122 * that we want to use so that we can restore them when we're 123 * done. 124 * 125 * Save some locals in the CPU tmp area to give us a little 126 * room to work. 127 */ 128 stn %l0, [%g2 + CPU_TMP1] 129 stn %l1, [%g2 + CPU_TMP2] 130 131#if defined(sun4v) 132 /* 133 * On sun4v save our input parameters (which are stored in the 134 * alternate globals) since we'll need to switch between alternate 135 * globals and normal globals, and on sun4v the alternate globals 136 * are not preserved across these types of switches. 137 */ 138 stn %l2, [%g2 + CPU_TMP3] 139 stn %l3, [%g2 + CPU_TMP4] 140 141 mov %g1, %l2 ! save %g1 in %l2 142 mov %g2, %l3 ! save %g2 in %l3 143#endif /* sun4v */ 144 145 /* 146 * Switch from the alternate to user globals to grab the syscall 147 * number. 148 */ 149 GLOBALS_SWAP(%l0) ! switch to normal globals 150 151 /* 152 * If the system call number is >= 1024, then it is a native 153 * syscall that doesn't need emulation. 154 */ 155 cmp %g1, 1024 ! is this a native syscall? 156 bl,a _indirect_check ! probably not, continue checking 157 mov %g1, %l1 ! delay slot - grab syscall number 158 159 /* 160 * This is a native syscall, probably from the emulation library. 161 * Subtract 1024 from the syscall number and let it go through. 162 */ 163 sub %g1, 1024, %g1 ! convert magic num to real syscall 164 ba _exit ! jump back into syscall path 165 GLOBALS_RESTORE(%l0) ! delay slot - 166 ! switch back to alternate globals 167 168_indirect_check: 169 /* 170 * If the system call number is 0 (SYS_syscall), then this might be 171 * an indirect syscall, in which case the actual syscall number 172 * would be stored in %o0, in which case we need to redo the 173 * the whole >= 1024 check. 174 */ 175 brnz,pt %g1, _emulation_check ! is this an indirect syscall? 176 nop ! if not, goto the emulation check 177 178 /* 179 * Indirect syscalls are only supported for 32 bit processes so 180 * consult the tstate address mask again. 181 */ 182 rdpr %tstate, %l1 ! %tstate.am is the trapping 183 andcc %l1, TSTATE_AM, %l1 ! threads address mask bit 184 be,a,pn %xcc, _exit 185 GLOBALS_RESTORE(%l0) ! delay slot - 186 ! switch back to alternate globals 187 188 /* 189 * The caller is 32 bit and this an indirect system call. 190 */ 191 cmp %o0, 1024 ! is this a native syscall? 192 bl,a _emulation_check ! no, goto the emulation check 193 mov %o0, %l1 ! delay slot - grab syscall number 194 195 /* 196 * This is native indirect syscall, probably from the emulation library. 197 * Subtract 1024 from the syscall number and let it go through. 198 */ 199 sub %o0, 1024, %o0 ! convert magic num to real syscall 200 ba _exit ! jump back into syscall path 201 GLOBALS_RESTORE(%l0) ! delay slot - 202 ! switch back to alternate globals 203 204_emulation_check: 205 GLOBALS_RESTORE(%l0) ! switch back to alternate globals 206 207 /* 208 * Check to see if we want to interpose on this system call. If 209 * not, we jump back into the normal syscall path and pretend 210 * nothing happened. %l1 contains the syscall we're invoking. 211 */ 212 set sn1_emulation_table, %g3 213 ldn [%g3], %g3 214 add %g3, %l1, %g3 215 ldub [%g3], %g3 216 brz %g3, _exit 217 nop 218 219 /* 220 * Find the address of the userspace handler. 221 * cpu->cpu_thread->t_procp->p_brand_data->spd_handler. 222 */ 223#if defined(sun4v) 224 ! restore the alternate global registers after incrementing %gl 225 mov %l3, %g2 226#endif /* sun4v */ 227 ldn [%g2 + CPU_THREAD], %g3 ! get thread ptr 228 ldn [%g3 + T_PROCP], %g4 ! get proc ptr 229 ldn [%g4 + P_BRAND_DATA], %g5 ! get brand data ptr 230 ldn [%g5 + SPD_HANDLER], %g5 ! get userland brand handler ptr 231 brz %g5, _exit ! has it been set? 232 nop 233 234 /* 235 * Make sure this isn't an agent lwp. We can't do syscall 236 * interposition for system calls made by a agent lwp. See 237 * the block comments in the top of the brand emulation library 238 * for more information. 239 */ 240 ldn [%g4 + P_AGENTTP], %g4 ! get agent thread ptr 241 cmp %g3, %g4 ! is this an agent thread? 242 be,pn %xcc, _exit ! if so don't emulate 243 nop 244 245 /* 246 * Now the magic happens. Grab the trap return address and then 247 * reset it to point to the user space handler. When we execute 248 * the 'done' instruction, we will jump into our handler instead of 249 * the user's code. We also stick the old return address in %g5, 250 * so we can return to the proper instruction in the user's code. 251 * Note: we also pass back the base address of the syscall 252 * emulation table. This is a performance hack to avoid having to 253 * look it up on every call. 254 */ 255 rdpr %tnpc, %l1 ! save old tnpc 256 wrpr %g0, %g5, %tnpc ! setup tnpc 257 GLOBALS_SWAP(%l0) ! switch to normal globals 258 mov %l1, %g5 ! pass tnpc to user code in %g5 259 GLOBALS_RESTORE(%l0) ! switch back to alternate globals 260 261 /* Update the address we're going to return to */ 262#if defined(sun4v) 263 set fast_trap_done_chk_intr, %l2 264#else /* !sun4v */ 265 set fast_trap_done_chk_intr, %g1 266#endif /* !sun4v */ 267 268_exit: 269 /* 270 * Restore registers before returning. 271 * 272 * Note that %g2 should be loaded with the CPU struct addr and 273 * %g1 should be loaded the address we're going to return to. 274 */ 275#if defined(sun4v) 276 ! restore the alternate global registers after incrementing %gl 277 mov %l2, %g1 ! restore %g1 from %l2 278 mov %l3, %g2 ! restore %g2 from %l3 279 280 ldn [%g2 + CPU_TMP4], %l3 ! restore locals 281 ldn [%g2 + CPU_TMP3], %l2 282#endif /* sun4v */ 283 284 ldn [%g2 + CPU_TMP2], %l1 ! restore locals 285 ldn [%g2 + CPU_TMP1], %l0 286 287 jmp %g1 288 nop 289 SET_SIZE(sn1_brand_syscall_callback_common) 290#endif /* !lint */ 291