fpu.c revision 1.2
1 /* $NetBSD: fpu.c,v 1.2 2003/08/31 01:26:34 chs Exp $ */ 2 3 /* 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matthew Fredette. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * FPU handling for NetBSD/hppa. 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.2 2003/08/31 01:26:34 chs Exp $"); 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/proc.h> 49 #include <sys/signalvar.h> 50 #include <sys/user.h> 51 52 #include <machine/cpu.h> 53 #include <machine/cpufunc.h> 54 #include <machine/frame.h> 55 #include <machine/reg.h> 56 57 #include <hppa/hppa/machdep.h> 58 59 #include "../spmath/float.h" 60 #include "../spmath/fpudispatch.h" 61 62 /* Some macros representing opcodes. */ 63 #define OPCODE_NOP 0x08000240 64 #define OPCODE_COPR_0_0 0x30000000 65 66 /* Some macros representing fields in load/store opcodes. */ 67 #define OPCODE_CMPLT_S 0x00002000 68 #define OPCODE_CMPLT_M 0x00000020 69 #define OPCODE_CMPLT_SM (OPCODE_CMPLT_S | OPCODE_CMPLT_M) 70 #define OPCODE_CMPLT_MB OPCODE_CMPLT_M 71 #define OPCODE_CMPLT_MA (OPCODE_CMPLT_S | OPCODE_CMPLT_M) 72 #define OPCODE_CMPLT (OPCODE_CMPLT_S | OPCODE_CMPLT_M) 73 #define OPCODE_DOUBLE 0x08000000 74 #define OPCODE_STORE 0x00000200 75 #define OPCODE_INDEXED 0x00001000 76 77 /* This is nonzero iff we're using a hardware FPU. */ 78 int fpu_present; 79 80 /* If we have any FPU, this is its version. */ 81 u_int fpu_version; 82 83 /* The number of times we have had to switch the FPU context. */ 84 u_int fpu_csw; 85 86 /* The U-space physical address of the proc in the FPU, or zero. */ 87 paddr_t fpu_cur_uspace; 88 89 /* In locore.S, this swaps states in and out of the FPU. */ 90 void hppa_fpu_swap __P((struct user *, struct user *)); 91 92 #ifdef FPEMUL 93 /* 94 * Given a trapframe and a general register number, the 95 * FRAME_REG macro returns a pointer to that general 96 * register. The _frame_reg_positions array is a lookup 97 * table, since the general registers aren't in order 98 * in a trapframe. 99 * 100 * NB: this more or less assumes that all members of 101 * struct trapframe are u_ints. 102 */ 103 #define FRAME_REG(f, reg, r0) \ 104 ((reg) == 0 ? (&r0) : ((&(f)->tf_t1) + _frame_reg_positions[reg])) 105 #define _FRAME_POSITION(f) \ 106 ((&((struct trapframe *) 0)->f) - (&((struct trapframe *) 0)->tf_t1)) 107 const int _frame_reg_positions[32] = { 108 -1, /* r0 */ 109 _FRAME_POSITION(tf_r1), 110 _FRAME_POSITION(tf_rp), /* r2 */ 111 _FRAME_POSITION(tf_r3), 112 _FRAME_POSITION(tf_r4), 113 _FRAME_POSITION(tf_r5), 114 _FRAME_POSITION(tf_r6), 115 _FRAME_POSITION(tf_r7), 116 _FRAME_POSITION(tf_r8), 117 _FRAME_POSITION(tf_r9), 118 _FRAME_POSITION(tf_r10), 119 _FRAME_POSITION(tf_r11), 120 _FRAME_POSITION(tf_r12), 121 _FRAME_POSITION(tf_r13), 122 _FRAME_POSITION(tf_r14), 123 _FRAME_POSITION(tf_r15), 124 _FRAME_POSITION(tf_r16), 125 _FRAME_POSITION(tf_r17), 126 _FRAME_POSITION(tf_r18), 127 _FRAME_POSITION(tf_t4), /* r19 */ 128 _FRAME_POSITION(tf_t3), /* r20 */ 129 _FRAME_POSITION(tf_t2), /* r21 */ 130 _FRAME_POSITION(tf_t1), /* r22 */ 131 _FRAME_POSITION(tf_arg3), /* r23 */ 132 _FRAME_POSITION(tf_arg2), /* r24 */ 133 _FRAME_POSITION(tf_arg1), /* r25 */ 134 _FRAME_POSITION(tf_arg0), /* r26 */ 135 _FRAME_POSITION(tf_dp), /* r27 */ 136 _FRAME_POSITION(tf_ret0), /* r28 */ 137 _FRAME_POSITION(tf_ret1), /* r29 */ 138 _FRAME_POSITION(tf_sp), /* r30 */ 139 _FRAME_POSITION(tf_r31), 140 }; 141 #endif /* FPEMUL */ 142 143 /* 144 * Bootstraps the FPU. 145 */ 146 void 147 hppa_fpu_bootstrap(u_int ccr_enable) 148 { 149 u_int32_t junk[2]; 150 u_int32_t version[2]; 151 extern u_int hppa_fpu_nop0; 152 extern u_int hppa_fpu_nop1; 153 154 /* See if we have a present and functioning hardware FPU. */ 155 fpu_present = (ccr_enable & HPPA_FPUS) == HPPA_FPUS; 156 157 /* Initialize the FPU and get its version. */ 158 if (fpu_present) { 159 160 /* 161 * To somewhat optimize the emulation 162 * assist trap handling and context 163 * switching (to save them from having 164 * to always load and check fpu_present), 165 * there are two instructions in locore.S 166 * that are replaced with nops when 167 * there is a hardware FPU. 168 */ 169 hppa_fpu_nop0 = OPCODE_NOP; 170 hppa_fpu_nop1 = OPCODE_NOP; 171 fcacheall(); 172 173 /* 174 * We track what process has the FPU, 175 * and how many times we have to swap 176 * in and out. 177 */ 178 179 /* 180 * The PA-RISC 1.1 Architecture manual is 181 * pretty clear that the copr,0,0 must be 182 * wrapped in double word stores of fr0, 183 * otherwise its operation is undefined. 184 */ 185 __asm __volatile( 186 " ldo %0, %%r22 \n" 187 " fstds %%fr0, 0(%%r22) \n" 188 " ldo %1, %%r22 \n" 189 " copr,0,0 \n" 190 " fstds %%fr0, 0(%%r22) \n" 191 : "=m" (junk), "=m" (version) : : "r22"); 192 193 /* 194 * Now mark that no process has the FPU, 195 * and disable it, so the first time it 196 * gets used the process' state gets 197 * swapped in. 198 */ 199 fpu_csw = 0; 200 fpu_cur_uspace = 0; 201 mtctl(ccr_enable & (CCR_MASK ^ HPPA_FPUS), CR_CCR); 202 } 203 #ifdef FPEMUL 204 else 205 /* 206 * XXX This is a hack - to avoid 207 * having to set up the emulator so 208 * it can work for one instruction for 209 * proc0, we dispatch the copr,0,0 opcode 210 * into the emulator directly. 211 */ 212 decode_0c(OPCODE_COPR_0_0, 0, 0, version); 213 #endif /* FPEMUL */ 214 fpu_version = version[0]; 215 } 216 217 /* 218 * If the given LWP has its state in the FPU, 219 * flush that state out into the LWP's PCB. 220 */ 221 void 222 hppa_fpu_flush(struct lwp *l) 223 { 224 struct trapframe *tf = l->l_md.md_regs; 225 226 /* 227 * If we have a hardware FPU, and this process' 228 * state is currently in it, swap it out. 229 */ 230 231 if (fpu_present && 232 fpu_cur_uspace != NULL && 233 fpu_cur_uspace == tf->tf_cr30) 234 hppa_fpu_swap(l->l_addr, NULL); 235 } 236 237 #ifdef FPEMUL 238 239 /* 240 * This emulates a coprocessor load/store instruction. 241 */ 242 static int hppa_fpu_ls __P((struct trapframe *, struct lwp *)); 243 static int 244 hppa_fpu_ls(struct trapframe *frame, struct lwp *l) 245 { 246 u_int inst, inst_b, inst_x, inst_s, inst_t; 247 int log2size; 248 u_int *base; 249 u_int offset, index, im5; 250 void *fpreg; 251 u_int r0 = 0; 252 253 /* 254 * Get the instruction that we're emulating, 255 * and break it down. Using HP bit notation, 256 * b is a five-bit field starting at bit 10, 257 * x is a five-bit field starting at bit 15, 258 * s is a two-bit field starting at bit 17, 259 * and t is a two-bit field starting at bit 31. 260 */ 261 inst = frame->tf_iir; 262 __asm __volatile( 263 " extru %4, 10, 5, %1 \n" 264 " extru %4, 15, 5, %2 \n" 265 " extru %4, 17, 2, %3 \n" 266 " extru %4, 31, 5, %4 \n" 267 : "=r" (inst_b), "=r" (inst_x), "=r" (inst_s), "=r" (inst_t) 268 : "r" (inst)); 269 270 /* 271 * The space must be the user's space, else we 272 * segfault. 273 */ 274 if (inst_s != l->l_addr->u_pcb.pcb_space) 275 return (EFAULT); 276 277 /* See whether or not this is a doubleword load/store. */ 278 log2size = (inst & OPCODE_DOUBLE) ? 3 : 2; 279 280 /* Get the floating point register. */ 281 fpreg = ((caddr_t)l->l_addr->u_pcb.pcb_fpregs) + (inst_t << log2size); 282 283 /* Get the base register. */ 284 base = FRAME_REG(frame, inst_b, r0); 285 286 /* Dispatch on whether or not this is an indexed load/store. */ 287 if (inst & OPCODE_INDEXED) { 288 289 /* Get the index register value. */ 290 index = *FRAME_REG(frame, inst_x, r0); 291 292 /* Dispatch on the completer. */ 293 switch (inst & OPCODE_CMPLT) { 294 case OPCODE_CMPLT_S: 295 offset = *base + (index << log2size); 296 break; 297 case OPCODE_CMPLT_M: 298 offset = *base; 299 *base = *base + index; 300 break; 301 case OPCODE_CMPLT_SM: 302 offset = *base; 303 *base = *base + (index << log2size); 304 break; 305 default: 306 offset = *base + index; 307 break; 308 } 309 } else { 310 311 /* Do a low_sign_ext(x, 5). */ 312 im5 = inst_x >> 1; 313 if (inst_x & 1) 314 im5 |= 0xfffffff0; 315 316 /* Dispatch on the completer. */ 317 switch (inst & OPCODE_CMPLT) { 318 case OPCODE_CMPLT_MB: 319 offset = *base + im5; 320 *base = *base + im5; 321 break; 322 case OPCODE_CMPLT_MA: 323 offset = *base; 324 *base = *base + im5; 325 break; 326 default: 327 offset = *base + im5; 328 break; 329 } 330 } 331 332 /* 333 * The offset we calculated must be the same as the 334 * offset in the IOR. 335 */ 336 KASSERT(offset == frame->tf_ior); 337 338 /* Perform the load or store. */ 339 return (inst & OPCODE_STORE) ? 340 copyout(fpreg, (void *) offset, 1 << log2size) : 341 copyin((const void *) offset, fpreg, 1 << log2size); 342 } 343 344 /* 345 * This is called to emulate an instruction. 346 */ 347 void 348 hppa_fpu_emulate(struct trapframe *frame, struct lwp *l) 349 { 350 u_int inst, opcode, class, sub; 351 u_int *fpregs; 352 int exception; 353 354 /* 355 * If the process' state is in any hardware FPU, 356 * flush it out - we need to operate on it. 357 */ 358 hppa_fpu_flush(l); 359 360 /* 361 * Get the instruction that we're emulating, 362 * and break it down. Using HP bit notation, 363 * the class is a two-bit field starting at 364 * bit 22, the opcode is a 6-bit field starting 365 * at bit 5, and sub for a class 1 instruction 366 * is a two bit field starting at bit 16, else 367 * it is a three bit field starting at bit 18. 368 */ 369 inst = frame->tf_iir; 370 __asm __volatile( 371 " extru %3, 22, 2, %1 \n" 372 " extru %3, 5, 6, %0 \n" 373 " extru %3, 18, 3, %2 \n" 374 " comib,<> 1, %1, 0 \n" 375 " extru %3, 16, 2, %2 \n" 376 : "=r" (opcode), "=r" (class), "=r" (sub) 377 : "r" (inst)); 378 379 /* Get this LWP's FPU registers. */ 380 fpregs = (u_int *) l->l_addr->u_pcb.pcb_fpregs; 381 382 /* Dispatch on the opcode. */ 383 switch (opcode) { 384 case 0x09: 385 case 0x0b: 386 if (hppa_fpu_ls(frame, l) != 0) 387 trapsignal(l, SIGSEGV, frame->tf_iioq_head); 388 return; 389 case 0x0c: 390 exception = decode_0c(inst, class, sub, fpregs); 391 break; 392 case 0x0e: 393 exception = decode_0e(inst, class, sub, fpregs); 394 break; 395 case 0x06: 396 exception = decode_06(inst, fpregs); 397 break; 398 case 0x26: 399 exception = decode_26(inst, fpregs); 400 break; 401 default: 402 exception = UNIMPLEMENTEDEXCEPTION; 403 break; 404 } 405 406 if (exception) 407 trapsignal(l, (exception & UNIMPLEMENTEDEXCEPTION) ? 408 SIGILL : SIGFPE, frame->tf_iioq_head); 409 } 410 411 #endif /* FPEMUL */ 412
Indexes created Mon Sep 29 21:09:56 GMT 2025