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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator
3 *
4 * MIPS floating point support
5 * Copyright (C) 1994-2000 Algorithmics Ltd.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
8 * Copyright (C) 2000 MIPS Technologies, Inc.
9 *
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * A complete emulator for MIPS coprocessor 1 instructions. This is
24 * required for #float(switch) or #float(trap), where it catches all
25 * COP1 instructions via the "CoProcessor Unusable" exception.
26 *
27 * More surprisingly it is also required for #float(ieee), to help out
28 * the hardware fpu at the boundaries of the IEEE-754 representation
29 * (denormalised values, infinities, underflow, etc). It is made
30 * quite nasty because emulation of some non-COP1 instructions is
31 * required, e.g. in branch delay slots.
32 *
33 * Note if you know that you won't have an fpu, then you'll get much
34 * better performance by compiling with -msoft-float!
35 */
36#include <linux/sched.h>
David Daneyb6ee75e2009-11-05 11:34:26 -080037#include <linux/module.h>
Atsushi Nemoto83fd38c2007-07-07 23:21:49 +090038#include <linux/debugfs.h>
Deng-Cheng Zhu7f788d22010-10-12 19:37:21 +080039#include <linux/perf_event.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41#include <asm/inst.h>
42#include <asm/bootinfo.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <asm/processor.h>
44#include <asm/ptrace.h>
45#include <asm/signal.h>
46#include <asm/mipsregs.h>
47#include <asm/fpu_emulator.h>
48#include <asm/uaccess.h>
49#include <asm/branch.h>
50
51#include "ieee754.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53/* Strap kernel emulator for full MIPS IV emulation */
54
55#ifdef __mips
56#undef __mips
57#endif
58#define __mips 4
59
60/* Function which emulates a floating point instruction. */
61
Atsushi Nemotoeae89072006-05-16 01:26:03 +090062static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 mips_instruction);
64
65#if __mips >= 4 && __mips != 32
66static int fpux_emu(struct pt_regs *,
David Daney515b0292010-10-21 16:32:26 -070067 struct mips_fpu_struct *, mips_instruction, void *__user *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#endif
69
Atsushi Nemotoeae89072006-05-16 01:26:03 +090070/* Further private data for which no space exists in mips_fpu_struct */
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
David Daneyb6ee75e2009-11-05 11:34:26 -080072#ifdef CONFIG_DEBUG_FS
73DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
74#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76/* Control registers */
77
78#define FPCREG_RID 0 /* $0 = revision id */
79#define FPCREG_CSR 31 /* $31 = csr */
80
Shane McDonald95e8f632010-05-06 23:26:57 -060081/* Determine rounding mode from the RM bits of the FCSR */
82#define modeindex(v) ((v) & FPU_CSR_RM)
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084/* Convert Mips rounding mode (0..3) to IEEE library modes. */
85static const unsigned char ieee_rm[4] = {
Ralf Baechlecd21dfc2005-04-28 13:39:10 +000086 [FPU_CSR_RN] = IEEE754_RN,
87 [FPU_CSR_RZ] = IEEE754_RZ,
88 [FPU_CSR_RU] = IEEE754_RU,
89 [FPU_CSR_RD] = IEEE754_RD,
90};
91/* Convert IEEE library modes to Mips rounding mode (0..3). */
92static const unsigned char mips_rm[4] = {
93 [IEEE754_RN] = FPU_CSR_RN,
94 [IEEE754_RZ] = FPU_CSR_RZ,
95 [IEEE754_RD] = FPU_CSR_RD,
96 [IEEE754_RU] = FPU_CSR_RU,
Linus Torvalds1da177e2005-04-16 15:20:36 -070097};
98
99#if __mips >= 4
100/* convert condition code register number to csr bit */
101static const unsigned int fpucondbit[8] = {
102 FPU_CSR_COND0,
103 FPU_CSR_COND1,
104 FPU_CSR_COND2,
105 FPU_CSR_COND3,
106 FPU_CSR_COND4,
107 FPU_CSR_COND5,
108 FPU_CSR_COND6,
109 FPU_CSR_COND7
110};
111#endif
112
113
114/*
115 * Redundant with logic already in kernel/branch.c,
116 * embedded in compute_return_epc. At some point,
117 * a single subroutine should be used across both
118 * modules.
119 */
120static int isBranchInstr(mips_instruction * i)
121{
122 switch (MIPSInst_OPCODE(*i)) {
123 case spec_op:
124 switch (MIPSInst_FUNC(*i)) {
125 case jalr_op:
126 case jr_op:
127 return 1;
128 }
129 break;
130
131 case bcond_op:
132 switch (MIPSInst_RT(*i)) {
133 case bltz_op:
134 case bgez_op:
135 case bltzl_op:
136 case bgezl_op:
137 case bltzal_op:
138 case bgezal_op:
139 case bltzall_op:
140 case bgezall_op:
141 return 1;
142 }
143 break;
144
145 case j_op:
146 case jal_op:
147 case jalx_op:
148 case beq_op:
149 case bne_op:
150 case blez_op:
151 case bgtz_op:
152 case beql_op:
153 case bnel_op:
154 case blezl_op:
155 case bgtzl_op:
156 return 1;
157
158 case cop0_op:
159 case cop1_op:
160 case cop2_op:
161 case cop1x_op:
162 if (MIPSInst_RS(*i) == bc_op)
163 return 1;
164 break;
165 }
166
167 return 0;
168}
169
170/*
171 * In the Linux kernel, we support selection of FPR format on the
David Daneyda0bac32009-11-02 11:33:46 -0800172 * basis of the Status.FR bit. If an FPU is not present, the FR bit
173 * is hardwired to zero, which would imply a 32-bit FPU even for
Ralf Baechle51d943f2012-08-15 19:42:19 +0200174 * 64-bit CPUs so we rather look at TIF_32BIT_REGS.
175 * FPU emu is slow and bulky and optimizing this function offers fairly
176 * sizeable benefits so we try to be clever and make this function return
177 * a constant whenever possible, that is on 64-bit kernels without O32
178 * compatibility enabled and on 32-bit kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 */
David Daneyda0bac32009-11-02 11:33:46 -0800180static inline int cop1_64bit(struct pt_regs *xcp)
181{
Ralf Baechle51d943f2012-08-15 19:42:19 +0200182#if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32)
183 return 1;
184#elif defined(CONFIG_64BIT) && defined(CONFIG_MIPS32_O32)
David Daneyda0bac32009-11-02 11:33:46 -0800185 return !test_thread_flag(TIF_32BIT_REGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186#else
David Daneyda0bac32009-11-02 11:33:46 -0800187 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188#endif
David Daneyda0bac32009-11-02 11:33:46 -0800189}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
David Daneyda0bac32009-11-02 11:33:46 -0800191#define SIFROMREG(si, x) ((si) = cop1_64bit(xcp) || !(x & 1) ? \
192 (int)ctx->fpr[x] : (int)(ctx->fpr[x & ~1] >> 32))
193
194#define SITOREG(si, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = \
195 cop1_64bit(xcp) || !(x & 1) ? \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \
197 ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32)
198
David Daneyda0bac32009-11-02 11:33:46 -0800199#define DIFROMREG(di, x) ((di) = ctx->fpr[x & ~(cop1_64bit(xcp) == 0)])
200#define DITOREG(di, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = (di))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
Ralf Baechle21a151d2007-10-11 23:46:15 +0100202#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
203#define SPTOREG(sp, x) SITOREG((sp).bits, x)
204#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
205#define DPTOREG(dp, x) DITOREG((dp).bits, x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207/*
208 * Emulate the single floating point instruction pointed at by EPC.
209 * Two instructions if the instruction is in a branch delay slot.
210 */
211
David Daney515b0292010-10-21 16:32:26 -0700212static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
213 void *__user *fault_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
215 mips_instruction ir;
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900216 unsigned long emulpc, contpc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 unsigned int cond;
218
David Daney515b0292010-10-21 16:32:26 -0700219 if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800220 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700221 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return SIGBUS;
223 }
David Daney515b0292010-10-21 16:32:26 -0700224 if (__get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) {
225 MIPS_FPU_EMU_INC_STATS(errors);
226 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
227 return SIGSEGV;
228 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 /* XXX NEC Vr54xx bug workaround */
231 if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir))
232 xcp->cp0_cause &= ~CAUSEF_BD;
233
234 if (xcp->cp0_cause & CAUSEF_BD) {
235 /*
236 * The instruction to be emulated is in a branch delay slot
237 * which means that we have to emulate the branch instruction
238 * BEFORE we do the cop1 instruction.
239 *
240 * This branch could be a COP1 branch, but in that case we
241 * would have had a trap for that instruction, and would not
242 * come through this route.
243 *
244 * Linux MIPS branch emulator operates on context, updating the
245 * cp0_epc.
246 */
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900247 emulpc = xcp->cp0_epc + 4; /* Snapshot emulation target */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
Maneesh Sonid8d4e3a2011-11-08 17:07:11 +0530249 if (__compute_return_epc(xcp) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250#ifdef CP1DBG
251 printk("failed to emulate branch at %p\n",
Ralf Baechle333d1f62005-02-28 17:55:57 +0000252 (void *) (xcp->cp0_epc));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253#endif
254 return SIGILL;
255 }
David Daney515b0292010-10-21 16:32:26 -0700256 if (!access_ok(VERIFY_READ, emulpc, sizeof(mips_instruction))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800257 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700258 *fault_addr = (mips_instruction __user *)emulpc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 return SIGBUS;
260 }
David Daney515b0292010-10-21 16:32:26 -0700261 if (__get_user(ir, (mips_instruction __user *) emulpc)) {
262 MIPS_FPU_EMU_INC_STATS(errors);
263 *fault_addr = (mips_instruction __user *)emulpc;
264 return SIGSEGV;
265 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 /* __compute_return_epc() will have updated cp0_epc */
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900267 contpc = xcp->cp0_epc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 /* In order not to confuse ptrace() et al, tweak context */
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900269 xcp->cp0_epc = emulpc - 4;
Ralf Baechle333d1f62005-02-28 17:55:57 +0000270 } else {
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900271 emulpc = xcp->cp0_epc;
272 contpc = xcp->cp0_epc + 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 }
274
275 emul:
Peter Zijlstraa8b0ca12011-06-27 14:41:57 +0200276 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
David Daneyb6ee75e2009-11-05 11:34:26 -0800277 MIPS_FPU_EMU_INC_STATS(emulated);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 switch (MIPSInst_OPCODE(ir)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 case ldc1_op:{
Ralf Baechle3fccc012005-10-23 13:58:21 +0100280 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 MIPSInst_SIMM(ir));
282 u64 val;
283
David Daneyb6ee75e2009-11-05 11:34:26 -0800284 MIPS_FPU_EMU_INC_STATS(loads);
David Daney515b0292010-10-21 16:32:26 -0700285
286 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800287 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700288 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 return SIGBUS;
290 }
David Daney515b0292010-10-21 16:32:26 -0700291 if (__get_user(val, va)) {
292 MIPS_FPU_EMU_INC_STATS(errors);
293 *fault_addr = va;
294 return SIGSEGV;
295 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 DITOREG(val, MIPSInst_RT(ir));
297 break;
298 }
299
300 case sdc1_op:{
Ralf Baechle3fccc012005-10-23 13:58:21 +0100301 u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 MIPSInst_SIMM(ir));
303 u64 val;
304
David Daneyb6ee75e2009-11-05 11:34:26 -0800305 MIPS_FPU_EMU_INC_STATS(stores);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 DIFROMREG(val, MIPSInst_RT(ir));
David Daney515b0292010-10-21 16:32:26 -0700307 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800308 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700309 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 return SIGBUS;
311 }
David Daney515b0292010-10-21 16:32:26 -0700312 if (__put_user(val, va)) {
313 MIPS_FPU_EMU_INC_STATS(errors);
314 *fault_addr = va;
315 return SIGSEGV;
316 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 break;
318 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
320 case lwc1_op:{
Ralf Baechle3fccc012005-10-23 13:58:21 +0100321 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 MIPSInst_SIMM(ir));
323 u32 val;
324
David Daneyb6ee75e2009-11-05 11:34:26 -0800325 MIPS_FPU_EMU_INC_STATS(loads);
David Daney515b0292010-10-21 16:32:26 -0700326 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800327 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700328 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 return SIGBUS;
330 }
David Daney515b0292010-10-21 16:32:26 -0700331 if (__get_user(val, va)) {
332 MIPS_FPU_EMU_INC_STATS(errors);
333 *fault_addr = va;
334 return SIGSEGV;
335 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 SITOREG(val, MIPSInst_RT(ir));
337 break;
338 }
339
340 case swc1_op:{
Ralf Baechle3fccc012005-10-23 13:58:21 +0100341 u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 MIPSInst_SIMM(ir));
343 u32 val;
344
David Daneyb6ee75e2009-11-05 11:34:26 -0800345 MIPS_FPU_EMU_INC_STATS(stores);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 SIFROMREG(val, MIPSInst_RT(ir));
David Daney515b0292010-10-21 16:32:26 -0700347 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800348 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700349 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return SIGBUS;
351 }
David Daney515b0292010-10-21 16:32:26 -0700352 if (__put_user(val, va)) {
353 MIPS_FPU_EMU_INC_STATS(errors);
354 *fault_addr = va;
355 return SIGSEGV;
356 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 break;
358 }
359
360 case cop1_op:
361 switch (MIPSInst_RS(ir)) {
362
Ralf Baechle4b724ef2005-10-23 15:05:47 +0100363#if defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 case dmfc_op:
365 /* copregister fs -> gpr[rt] */
366 if (MIPSInst_RT(ir) != 0) {
367 DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
368 MIPSInst_RD(ir));
369 }
370 break;
371
372 case dmtc_op:
373 /* copregister fs <- rt */
374 DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
375 break;
376#endif
377
378 case mfc_op:
379 /* copregister rd -> gpr[rt] */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 if (MIPSInst_RT(ir) != 0) {
381 SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
382 MIPSInst_RD(ir));
383 }
384 break;
385
386 case mtc_op:
387 /* copregister rd <- rt */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
389 break;
390
391 case cfc_op:{
392 /* cop control register rd -> gpr[rt] */
393 u32 value;
394
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 if (MIPSInst_RD(ir) == FPCREG_CSR) {
396 value = ctx->fcr31;
Shane McDonald3f135532010-05-07 00:02:09 -0600397 value = (value & ~FPU_CSR_RM) |
398 mips_rm[modeindex(value)];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399#ifdef CSRTRACE
400 printk("%p gpr[%d]<-csr=%08x\n",
Ralf Baechle333d1f62005-02-28 17:55:57 +0000401 (void *) (xcp->cp0_epc),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 MIPSInst_RT(ir), value);
403#endif
404 }
405 else if (MIPSInst_RD(ir) == FPCREG_RID)
406 value = 0;
407 else
408 value = 0;
409 if (MIPSInst_RT(ir))
410 xcp->regs[MIPSInst_RT(ir)] = value;
411 break;
412 }
413
414 case ctc_op:{
415 /* copregister rd <- rt */
416 u32 value;
417
418 if (MIPSInst_RT(ir) == 0)
419 value = 0;
420 else
421 value = xcp->regs[MIPSInst_RT(ir)];
422
423 /* we only have one writable control reg
424 */
425 if (MIPSInst_RD(ir) == FPCREG_CSR) {
426#ifdef CSRTRACE
427 printk("%p gpr[%d]->csr=%08x\n",
Ralf Baechle333d1f62005-02-28 17:55:57 +0000428 (void *) (xcp->cp0_epc),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 MIPSInst_RT(ir), value);
430#endif
Shane McDonald95e8f632010-05-06 23:26:57 -0600431
432 /*
433 * Don't write reserved bits,
434 * and convert to ieee library modes
435 */
436 ctx->fcr31 = (value &
437 ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
438 ieee_rm[modeindex(value)];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 }
440 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
441 return SIGFPE;
442 }
443 break;
444 }
445
446 case bc_op:{
447 int likely = 0;
448
449 if (xcp->cp0_cause & CAUSEF_BD)
450 return SIGILL;
451
452#if __mips >= 4
453 cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
454#else
455 cond = ctx->fcr31 & FPU_CSR_COND;
456#endif
457 switch (MIPSInst_RT(ir) & 3) {
458 case bcfl_op:
459 likely = 1;
460 case bcf_op:
461 cond = !cond;
462 break;
463 case bctl_op:
464 likely = 1;
465 case bct_op:
466 break;
467 default:
468 /* thats an illegal instruction */
469 return SIGILL;
470 }
471
472 xcp->cp0_cause |= CAUSEF_BD;
473 if (cond) {
474 /* branch taken: emulate dslot
475 * instruction
476 */
477 xcp->cp0_epc += 4;
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900478 contpc = (xcp->cp0_epc +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 (MIPSInst_SIMM(ir) << 2));
480
David Daney515b0292010-10-21 16:32:26 -0700481 if (!access_ok(VERIFY_READ, xcp->cp0_epc,
482 sizeof(mips_instruction))) {
483 MIPS_FPU_EMU_INC_STATS(errors);
484 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
485 return SIGBUS;
486 }
487 if (__get_user(ir,
Ralf Baechle3fccc012005-10-23 13:58:21 +0100488 (mips_instruction __user *) xcp->cp0_epc)) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800489 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700490 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
491 return SIGSEGV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 }
493
494 switch (MIPSInst_OPCODE(ir)) {
495 case lwc1_op:
496 case swc1_op:
Ralf Baechle4b724ef2005-10-23 15:05:47 +0100497#if (__mips >= 2 || defined(__mips64))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 case ldc1_op:
499 case sdc1_op:
500#endif
501 case cop1_op:
502#if __mips >= 4 && __mips != 32
503 case cop1x_op:
504#endif
505 /* its one of ours */
506 goto emul;
507#if __mips >= 4
508 case spec_op:
509 if (MIPSInst_FUNC(ir) == movc_op)
510 goto emul;
511 break;
512#endif
513 }
514
515 /*
516 * Single step the non-cp1
517 * instruction in the dslot
518 */
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900519 return mips_dsemul(xcp, ir, contpc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 }
521 else {
522 /* branch not taken */
523 if (likely) {
524 /*
525 * branch likely nullifies
526 * dslot if not taken
527 */
528 xcp->cp0_epc += 4;
529 contpc += 4;
530 /*
531 * else continue & execute
532 * dslot as normal insn
533 */
534 }
535 }
536 break;
537 }
538
539 default:
540 if (!(MIPSInst_RS(ir) & 0x10))
541 return SIGILL;
542 {
543 int sig;
544
545 /* a real fpu computation instruction */
546 if ((sig = fpu_emu(xcp, ctx, ir)))
547 return sig;
548 }
549 }
550 break;
551
552#if __mips >= 4 && __mips != 32
553 case cop1x_op:{
David Daney515b0292010-10-21 16:32:26 -0700554 int sig = fpux_emu(xcp, ctx, ir, fault_addr);
555 if (sig)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 return sig;
557 break;
558 }
559#endif
560
561#if __mips >= 4
562 case spec_op:
563 if (MIPSInst_FUNC(ir) != movc_op)
564 return SIGILL;
565 cond = fpucondbit[MIPSInst_RT(ir) >> 2];
566 if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
567 xcp->regs[MIPSInst_RD(ir)] =
568 xcp->regs[MIPSInst_RS(ir)];
569 break;
570#endif
571
572 default:
573 return SIGILL;
574 }
575
576 /* we did it !! */
Atsushi Nemotoe70dfc12007-07-13 23:02:29 +0900577 xcp->cp0_epc = contpc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 xcp->cp0_cause &= ~CAUSEF_BD;
Ralf Baechle333d1f62005-02-28 17:55:57 +0000579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 return 0;
581}
582
583/*
584 * Conversion table from MIPS compare ops 48-63
585 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
586 */
587static const unsigned char cmptab[8] = {
588 0, /* cmp_0 (sig) cmp_sf */
589 IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
590 IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
591 IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
592 IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
593 IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
594 IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
595 IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
596};
597
598
599#if __mips >= 4 && __mips != 32
600
601/*
602 * Additional MIPS4 instructions
603 */
604
605#define DEF3OP(name, p, f1, f2, f3) \
Ralf Baechle49a89ef2007-10-11 23:46:15 +0100606static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 ieee754##p t) \
608{ \
Ralf Baechlecd21dfc2005-04-28 13:39:10 +0000609 struct _ieee754_csr ieee754_csr_save; \
Ralf Baechle49a89ef2007-10-11 23:46:15 +0100610 s = f1(s, t); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 ieee754_csr_save = ieee754_csr; \
Ralf Baechle49a89ef2007-10-11 23:46:15 +0100612 s = f2(s, r); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 ieee754_csr_save.cx |= ieee754_csr.cx; \
614 ieee754_csr_save.sx |= ieee754_csr.sx; \
Ralf Baechle49a89ef2007-10-11 23:46:15 +0100615 s = f3(s); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 ieee754_csr.cx |= ieee754_csr_save.cx; \
617 ieee754_csr.sx |= ieee754_csr_save.sx; \
618 return s; \
619}
620
621static ieee754dp fpemu_dp_recip(ieee754dp d)
622{
623 return ieee754dp_div(ieee754dp_one(0), d);
624}
625
626static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
627{
628 return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
629}
630
631static ieee754sp fpemu_sp_recip(ieee754sp s)
632{
633 return ieee754sp_div(ieee754sp_one(0), s);
634}
635
636static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
637{
638 return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
639}
640
Ralf Baechle21a151d2007-10-11 23:46:15 +0100641DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
642DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
644DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
Ralf Baechle21a151d2007-10-11 23:46:15 +0100645DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
646DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
648DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
649
Atsushi Nemotoeae89072006-05-16 01:26:03 +0900650static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
David Daney515b0292010-10-21 16:32:26 -0700651 mips_instruction ir, void *__user *fault_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652{
653 unsigned rcsr = 0; /* resulting csr */
654
David Daneyb6ee75e2009-11-05 11:34:26 -0800655 MIPS_FPU_EMU_INC_STATS(cp1xops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
657 switch (MIPSInst_FMA_FFMT(ir)) {
658 case s_fmt:{ /* 0 */
659
660 ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
661 ieee754sp fd, fr, fs, ft;
Ralf Baechle3fccc012005-10-23 13:58:21 +0100662 u32 __user *va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 u32 val;
664
665 switch (MIPSInst_FUNC(ir)) {
666 case lwxc1_op:
Ralf Baechle3fccc012005-10-23 13:58:21 +0100667 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 xcp->regs[MIPSInst_FT(ir)]);
669
David Daneyb6ee75e2009-11-05 11:34:26 -0800670 MIPS_FPU_EMU_INC_STATS(loads);
David Daney515b0292010-10-21 16:32:26 -0700671 if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800672 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700673 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 return SIGBUS;
675 }
David Daney515b0292010-10-21 16:32:26 -0700676 if (__get_user(val, va)) {
677 MIPS_FPU_EMU_INC_STATS(errors);
678 *fault_addr = va;
679 return SIGSEGV;
680 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 SITOREG(val, MIPSInst_FD(ir));
682 break;
683
684 case swxc1_op:
Ralf Baechle3fccc012005-10-23 13:58:21 +0100685 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 xcp->regs[MIPSInst_FT(ir)]);
687
David Daneyb6ee75e2009-11-05 11:34:26 -0800688 MIPS_FPU_EMU_INC_STATS(stores);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690 SIFROMREG(val, MIPSInst_FS(ir));
David Daney515b0292010-10-21 16:32:26 -0700691 if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
692 MIPS_FPU_EMU_INC_STATS(errors);
693 *fault_addr = va;
694 return SIGBUS;
695 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 if (put_user(val, va)) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800697 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700698 *fault_addr = va;
699 return SIGSEGV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 }
701 break;
702
703 case madd_s_op:
704 handler = fpemu_sp_madd;
705 goto scoptop;
706 case msub_s_op:
707 handler = fpemu_sp_msub;
708 goto scoptop;
709 case nmadd_s_op:
710 handler = fpemu_sp_nmadd;
711 goto scoptop;
712 case nmsub_s_op:
713 handler = fpemu_sp_nmsub;
714 goto scoptop;
715
716 scoptop:
717 SPFROMREG(fr, MIPSInst_FR(ir));
718 SPFROMREG(fs, MIPSInst_FS(ir));
719 SPFROMREG(ft, MIPSInst_FT(ir));
720 fd = (*handler) (fr, fs, ft);
721 SPTOREG(fd, MIPSInst_FD(ir));
722
723 copcsr:
724 if (ieee754_cxtest(IEEE754_INEXACT))
725 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
726 if (ieee754_cxtest(IEEE754_UNDERFLOW))
727 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
728 if (ieee754_cxtest(IEEE754_OVERFLOW))
729 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
730 if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
731 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
732
733 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
735 /*printk ("SIGFPE: fpu csr = %08x\n",
736 ctx->fcr31); */
737 return SIGFPE;
738 }
739
740 break;
741
742 default:
743 return SIGILL;
744 }
745 break;
746 }
747
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 case d_fmt:{ /* 1 */
749 ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
750 ieee754dp fd, fr, fs, ft;
Ralf Baechle3fccc012005-10-23 13:58:21 +0100751 u64 __user *va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 u64 val;
753
754 switch (MIPSInst_FUNC(ir)) {
755 case ldxc1_op:
Ralf Baechle3fccc012005-10-23 13:58:21 +0100756 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 xcp->regs[MIPSInst_FT(ir)]);
758
David Daneyb6ee75e2009-11-05 11:34:26 -0800759 MIPS_FPU_EMU_INC_STATS(loads);
David Daney515b0292010-10-21 16:32:26 -0700760 if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800761 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700762 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 return SIGBUS;
764 }
David Daney515b0292010-10-21 16:32:26 -0700765 if (__get_user(val, va)) {
766 MIPS_FPU_EMU_INC_STATS(errors);
767 *fault_addr = va;
768 return SIGSEGV;
769 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 DITOREG(val, MIPSInst_FD(ir));
771 break;
772
773 case sdxc1_op:
Ralf Baechle3fccc012005-10-23 13:58:21 +0100774 va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 xcp->regs[MIPSInst_FT(ir)]);
776
David Daneyb6ee75e2009-11-05 11:34:26 -0800777 MIPS_FPU_EMU_INC_STATS(stores);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 DIFROMREG(val, MIPSInst_FS(ir));
David Daney515b0292010-10-21 16:32:26 -0700779 if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
David Daneyb6ee75e2009-11-05 11:34:26 -0800780 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -0700781 *fault_addr = va;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 return SIGBUS;
783 }
David Daney515b0292010-10-21 16:32:26 -0700784 if (__put_user(val, va)) {
785 MIPS_FPU_EMU_INC_STATS(errors);
786 *fault_addr = va;
787 return SIGSEGV;
788 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 break;
790
791 case madd_d_op:
792 handler = fpemu_dp_madd;
793 goto dcoptop;
794 case msub_d_op:
795 handler = fpemu_dp_msub;
796 goto dcoptop;
797 case nmadd_d_op:
798 handler = fpemu_dp_nmadd;
799 goto dcoptop;
800 case nmsub_d_op:
801 handler = fpemu_dp_nmsub;
802 goto dcoptop;
803
804 dcoptop:
805 DPFROMREG(fr, MIPSInst_FR(ir));
806 DPFROMREG(fs, MIPSInst_FS(ir));
807 DPFROMREG(ft, MIPSInst_FT(ir));
808 fd = (*handler) (fr, fs, ft);
809 DPTOREG(fd, MIPSInst_FD(ir));
810 goto copcsr;
811
812 default:
813 return SIGILL;
814 }
815 break;
816 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817
818 case 0x7: /* 7 */
819 if (MIPSInst_FUNC(ir) != pfetch_op) {
820 return SIGILL;
821 }
822 /* ignore prefx operation */
823 break;
824
825 default:
826 return SIGILL;
827 }
828
829 return 0;
830}
831#endif
832
833
834
835/*
836 * Emulate a single COP1 arithmetic instruction.
837 */
Atsushi Nemotoeae89072006-05-16 01:26:03 +0900838static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 mips_instruction ir)
840{
841 int rfmt; /* resulting format */
842 unsigned rcsr = 0; /* resulting csr */
843 unsigned cond;
844 union {
845 ieee754dp d;
846 ieee754sp s;
847 int w;
Yoichi Yuasa766160c2005-09-03 15:56:22 -0700848#ifdef __mips64
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 s64 l;
850#endif
851 } rv; /* resulting value */
852
David Daneyb6ee75e2009-11-05 11:34:26 -0800853 MIPS_FPU_EMU_INC_STATS(cp1ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
855 case s_fmt:{ /* 0 */
856 union {
857 ieee754sp(*b) (ieee754sp, ieee754sp);
858 ieee754sp(*u) (ieee754sp);
859 } handler;
860
861 switch (MIPSInst_FUNC(ir)) {
862 /* binary ops */
863 case fadd_op:
864 handler.b = ieee754sp_add;
865 goto scopbop;
866 case fsub_op:
867 handler.b = ieee754sp_sub;
868 goto scopbop;
869 case fmul_op:
870 handler.b = ieee754sp_mul;
871 goto scopbop;
872 case fdiv_op:
873 handler.b = ieee754sp_div;
874 goto scopbop;
875
876 /* unary ops */
Ralf Baechle587cb982005-09-15 08:52:34 +0000877#if __mips >= 2 || defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 case fsqrt_op:
879 handler.u = ieee754sp_sqrt;
880 goto scopuop;
881#endif
882#if __mips >= 4 && __mips != 32
883 case frsqrt_op:
884 handler.u = fpemu_sp_rsqrt;
885 goto scopuop;
886 case frecip_op:
887 handler.u = fpemu_sp_recip;
888 goto scopuop;
889#endif
890#if __mips >= 4
891 case fmovc_op:
892 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
893 if (((ctx->fcr31 & cond) != 0) !=
894 ((MIPSInst_FT(ir) & 1) != 0))
895 return 0;
896 SPFROMREG(rv.s, MIPSInst_FS(ir));
897 break;
898 case fmovz_op:
899 if (xcp->regs[MIPSInst_FT(ir)] != 0)
900 return 0;
901 SPFROMREG(rv.s, MIPSInst_FS(ir));
902 break;
903 case fmovn_op:
904 if (xcp->regs[MIPSInst_FT(ir)] == 0)
905 return 0;
906 SPFROMREG(rv.s, MIPSInst_FS(ir));
907 break;
908#endif
909 case fabs_op:
910 handler.u = ieee754sp_abs;
911 goto scopuop;
912 case fneg_op:
913 handler.u = ieee754sp_neg;
914 goto scopuop;
915 case fmov_op:
916 /* an easy one */
917 SPFROMREG(rv.s, MIPSInst_FS(ir));
918 goto copcsr;
919
920 /* binary op on handler */
921 scopbop:
922 {
923 ieee754sp fs, ft;
924
925 SPFROMREG(fs, MIPSInst_FS(ir));
926 SPFROMREG(ft, MIPSInst_FT(ir));
927
928 rv.s = (*handler.b) (fs, ft);
929 goto copcsr;
930 }
931 scopuop:
932 {
933 ieee754sp fs;
934
935 SPFROMREG(fs, MIPSInst_FS(ir));
936 rv.s = (*handler.u) (fs);
937 goto copcsr;
938 }
939 copcsr:
940 if (ieee754_cxtest(IEEE754_INEXACT))
941 rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
942 if (ieee754_cxtest(IEEE754_UNDERFLOW))
943 rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
944 if (ieee754_cxtest(IEEE754_OVERFLOW))
945 rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
946 if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
947 rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
948 if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
949 rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
950 break;
951
952 /* unary conv ops */
953 case fcvts_op:
954 return SIGILL; /* not defined */
955 case fcvtd_op:{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 ieee754sp fs;
957
958 SPFROMREG(fs, MIPSInst_FS(ir));
959 rv.d = ieee754dp_fsp(fs);
960 rfmt = d_fmt;
961 goto copcsr;
962 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 case fcvtw_op:{
964 ieee754sp fs;
965
966 SPFROMREG(fs, MIPSInst_FS(ir));
967 rv.w = ieee754sp_tint(fs);
968 rfmt = w_fmt;
969 goto copcsr;
970 }
971
Ralf Baechle587cb982005-09-15 08:52:34 +0000972#if __mips >= 2 || defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 case fround_op:
974 case ftrunc_op:
975 case fceil_op:
976 case ffloor_op:{
977 unsigned int oldrm = ieee754_csr.rm;
978 ieee754sp fs;
979
980 SPFROMREG(fs, MIPSInst_FS(ir));
Shane McDonald3f135532010-05-07 00:02:09 -0600981 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 rv.w = ieee754sp_tint(fs);
983 ieee754_csr.rm = oldrm;
984 rfmt = w_fmt;
985 goto copcsr;
986 }
987#endif /* __mips >= 2 */
988
Ralf Baechle4b724ef2005-10-23 15:05:47 +0100989#if defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 case fcvtl_op:{
991 ieee754sp fs;
992
993 SPFROMREG(fs, MIPSInst_FS(ir));
994 rv.l = ieee754sp_tlong(fs);
995 rfmt = l_fmt;
996 goto copcsr;
997 }
998
999 case froundl_op:
1000 case ftruncl_op:
1001 case fceill_op:
1002 case ffloorl_op:{
1003 unsigned int oldrm = ieee754_csr.rm;
1004 ieee754sp fs;
1005
1006 SPFROMREG(fs, MIPSInst_FS(ir));
Shane McDonald3f135532010-05-07 00:02:09 -06001007 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 rv.l = ieee754sp_tlong(fs);
1009 ieee754_csr.rm = oldrm;
1010 rfmt = l_fmt;
1011 goto copcsr;
1012 }
Ralf Baechle4b724ef2005-10-23 15:05:47 +01001013#endif /* defined(__mips64) */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
1015 default:
1016 if (MIPSInst_FUNC(ir) >= fcmp_op) {
1017 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1018 ieee754sp fs, ft;
1019
1020 SPFROMREG(fs, MIPSInst_FS(ir));
1021 SPFROMREG(ft, MIPSInst_FT(ir));
1022 rv.w = ieee754sp_cmp(fs, ft,
1023 cmptab[cmpop & 0x7], cmpop & 0x8);
1024 rfmt = -1;
1025 if ((cmpop & 0x8) && ieee754_cxtest
1026 (IEEE754_INVALID_OPERATION))
1027 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1028 else
1029 goto copcsr;
1030
1031 }
1032 else {
1033 return SIGILL;
1034 }
1035 break;
1036 }
1037 break;
1038 }
1039
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 case d_fmt:{
1041 union {
1042 ieee754dp(*b) (ieee754dp, ieee754dp);
1043 ieee754dp(*u) (ieee754dp);
1044 } handler;
1045
1046 switch (MIPSInst_FUNC(ir)) {
1047 /* binary ops */
1048 case fadd_op:
1049 handler.b = ieee754dp_add;
1050 goto dcopbop;
1051 case fsub_op:
1052 handler.b = ieee754dp_sub;
1053 goto dcopbop;
1054 case fmul_op:
1055 handler.b = ieee754dp_mul;
1056 goto dcopbop;
1057 case fdiv_op:
1058 handler.b = ieee754dp_div;
1059 goto dcopbop;
1060
1061 /* unary ops */
Ralf Baechle587cb982005-09-15 08:52:34 +00001062#if __mips >= 2 || defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 case fsqrt_op:
1064 handler.u = ieee754dp_sqrt;
1065 goto dcopuop;
1066#endif
1067#if __mips >= 4 && __mips != 32
1068 case frsqrt_op:
1069 handler.u = fpemu_dp_rsqrt;
1070 goto dcopuop;
1071 case frecip_op:
1072 handler.u = fpemu_dp_recip;
1073 goto dcopuop;
1074#endif
1075#if __mips >= 4
1076 case fmovc_op:
1077 cond = fpucondbit[MIPSInst_FT(ir) >> 2];
1078 if (((ctx->fcr31 & cond) != 0) !=
1079 ((MIPSInst_FT(ir) & 1) != 0))
1080 return 0;
1081 DPFROMREG(rv.d, MIPSInst_FS(ir));
1082 break;
1083 case fmovz_op:
1084 if (xcp->regs[MIPSInst_FT(ir)] != 0)
1085 return 0;
1086 DPFROMREG(rv.d, MIPSInst_FS(ir));
1087 break;
1088 case fmovn_op:
1089 if (xcp->regs[MIPSInst_FT(ir)] == 0)
1090 return 0;
1091 DPFROMREG(rv.d, MIPSInst_FS(ir));
1092 break;
1093#endif
1094 case fabs_op:
1095 handler.u = ieee754dp_abs;
1096 goto dcopuop;
1097
1098 case fneg_op:
1099 handler.u = ieee754dp_neg;
1100 goto dcopuop;
1101
1102 case fmov_op:
1103 /* an easy one */
1104 DPFROMREG(rv.d, MIPSInst_FS(ir));
1105 goto copcsr;
1106
1107 /* binary op on handler */
1108 dcopbop:{
1109 ieee754dp fs, ft;
1110
1111 DPFROMREG(fs, MIPSInst_FS(ir));
1112 DPFROMREG(ft, MIPSInst_FT(ir));
1113
1114 rv.d = (*handler.b) (fs, ft);
1115 goto copcsr;
1116 }
1117 dcopuop:{
1118 ieee754dp fs;
1119
1120 DPFROMREG(fs, MIPSInst_FS(ir));
1121 rv.d = (*handler.u) (fs);
1122 goto copcsr;
1123 }
1124
1125 /* unary conv ops */
1126 case fcvts_op:{
1127 ieee754dp fs;
1128
1129 DPFROMREG(fs, MIPSInst_FS(ir));
1130 rv.s = ieee754sp_fdp(fs);
1131 rfmt = s_fmt;
1132 goto copcsr;
1133 }
1134 case fcvtd_op:
1135 return SIGILL; /* not defined */
1136
1137 case fcvtw_op:{
1138 ieee754dp fs;
1139
1140 DPFROMREG(fs, MIPSInst_FS(ir));
1141 rv.w = ieee754dp_tint(fs); /* wrong */
1142 rfmt = w_fmt;
1143 goto copcsr;
1144 }
1145
Ralf Baechle587cb982005-09-15 08:52:34 +00001146#if __mips >= 2 || defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 case fround_op:
1148 case ftrunc_op:
1149 case fceil_op:
1150 case ffloor_op:{
1151 unsigned int oldrm = ieee754_csr.rm;
1152 ieee754dp fs;
1153
1154 DPFROMREG(fs, MIPSInst_FS(ir));
Shane McDonald3f135532010-05-07 00:02:09 -06001155 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 rv.w = ieee754dp_tint(fs);
1157 ieee754_csr.rm = oldrm;
1158 rfmt = w_fmt;
1159 goto copcsr;
1160 }
1161#endif
1162
Ralf Baechle4b724ef2005-10-23 15:05:47 +01001163#if defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 case fcvtl_op:{
1165 ieee754dp fs;
1166
1167 DPFROMREG(fs, MIPSInst_FS(ir));
1168 rv.l = ieee754dp_tlong(fs);
1169 rfmt = l_fmt;
1170 goto copcsr;
1171 }
1172
1173 case froundl_op:
1174 case ftruncl_op:
1175 case fceill_op:
1176 case ffloorl_op:{
1177 unsigned int oldrm = ieee754_csr.rm;
1178 ieee754dp fs;
1179
1180 DPFROMREG(fs, MIPSInst_FS(ir));
Shane McDonald3f135532010-05-07 00:02:09 -06001181 ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 rv.l = ieee754dp_tlong(fs);
1183 ieee754_csr.rm = oldrm;
1184 rfmt = l_fmt;
1185 goto copcsr;
1186 }
Ralf Baechle4b724ef2005-10-23 15:05:47 +01001187#endif /* __mips >= 3 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188
1189 default:
1190 if (MIPSInst_FUNC(ir) >= fcmp_op) {
1191 unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
1192 ieee754dp fs, ft;
1193
1194 DPFROMREG(fs, MIPSInst_FS(ir));
1195 DPFROMREG(ft, MIPSInst_FT(ir));
1196 rv.w = ieee754dp_cmp(fs, ft,
1197 cmptab[cmpop & 0x7], cmpop & 0x8);
1198 rfmt = -1;
1199 if ((cmpop & 0x8)
1200 &&
1201 ieee754_cxtest
1202 (IEEE754_INVALID_OPERATION))
1203 rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
1204 else
1205 goto copcsr;
1206
1207 }
1208 else {
1209 return SIGILL;
1210 }
1211 break;
1212 }
1213 break;
1214 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215
1216 case w_fmt:{
1217 ieee754sp fs;
1218
1219 switch (MIPSInst_FUNC(ir)) {
1220 case fcvts_op:
1221 /* convert word to single precision real */
1222 SPFROMREG(fs, MIPSInst_FS(ir));
1223 rv.s = ieee754sp_fint(fs.bits);
1224 rfmt = s_fmt;
1225 goto copcsr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 case fcvtd_op:
1227 /* convert word to double precision real */
1228 SPFROMREG(fs, MIPSInst_FS(ir));
1229 rv.d = ieee754dp_fint(fs.bits);
1230 rfmt = d_fmt;
1231 goto copcsr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 default:
1233 return SIGILL;
1234 }
1235 break;
1236 }
1237
Ralf Baechle4b724ef2005-10-23 15:05:47 +01001238#if defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 case l_fmt:{
1240 switch (MIPSInst_FUNC(ir)) {
1241 case fcvts_op:
1242 /* convert long to single precision real */
1243 rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1244 rfmt = s_fmt;
1245 goto copcsr;
1246 case fcvtd_op:
1247 /* convert long to double precision real */
1248 rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
1249 rfmt = d_fmt;
1250 goto copcsr;
1251 default:
1252 return SIGILL;
1253 }
1254 break;
1255 }
1256#endif
1257
1258 default:
1259 return SIGILL;
1260 }
1261
1262 /*
1263 * Update the fpu CSR register for this operation.
1264 * If an exception is required, generate a tidy SIGFPE exception,
1265 * without updating the result register.
1266 * Note: cause exception bits do not accumulate, they are rewritten
1267 * for each op; only the flag/sticky bits accumulate.
1268 */
1269 ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
1270 if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
1271 /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
1272 return SIGFPE;
1273 }
1274
1275 /*
1276 * Now we can safely write the result back to the register file.
1277 */
1278 switch (rfmt) {
1279 case -1:{
1280#if __mips >= 4
1281 cond = fpucondbit[MIPSInst_FD(ir) >> 2];
1282#else
1283 cond = FPU_CSR_COND;
1284#endif
1285 if (rv.w)
1286 ctx->fcr31 |= cond;
1287 else
1288 ctx->fcr31 &= ~cond;
1289 break;
1290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 case d_fmt:
1292 DPTOREG(rv.d, MIPSInst_FD(ir));
1293 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 case s_fmt:
1295 SPTOREG(rv.s, MIPSInst_FD(ir));
1296 break;
1297 case w_fmt:
1298 SITOREG(rv.w, MIPSInst_FD(ir));
1299 break;
Ralf Baechle4b724ef2005-10-23 15:05:47 +01001300#if defined(__mips64)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 case l_fmt:
1302 DITOREG(rv.l, MIPSInst_FD(ir));
1303 break;
1304#endif
1305 default:
1306 return SIGILL;
1307 }
1308
1309 return 0;
1310}
1311
Atsushi Nemotoe04582b2006-10-09 00:10:01 +09001312int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
David Daney515b0292010-10-21 16:32:26 -07001313 int has_fpu, void *__user *fault_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314{
Ralf Baechle333d1f62005-02-28 17:55:57 +00001315 unsigned long oldepc, prevepc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 mips_instruction insn;
1317 int sig = 0;
1318
1319 oldepc = xcp->cp0_epc;
1320 do {
1321 prevepc = xcp->cp0_epc;
1322
David Daney515b0292010-10-21 16:32:26 -07001323 if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) {
David Daneyb6ee75e2009-11-05 11:34:26 -08001324 MIPS_FPU_EMU_INC_STATS(errors);
David Daney515b0292010-10-21 16:32:26 -07001325 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 return SIGBUS;
1327 }
David Daney515b0292010-10-21 16:32:26 -07001328 if (__get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) {
1329 MIPS_FPU_EMU_INC_STATS(errors);
1330 *fault_addr = (mips_instruction __user *)xcp->cp0_epc;
1331 return SIGSEGV;
1332 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 if (insn == 0)
1334 xcp->cp0_epc += 4; /* skip nops */
1335 else {
Ralf Baechlecd21dfc2005-04-28 13:39:10 +00001336 /*
1337 * The 'ieee754_csr' is an alias of
1338 * ctx->fcr31. No need to copy ctx->fcr31 to
1339 * ieee754_csr. But ieee754_csr.rm is ieee
1340 * library modes. (not mips rounding mode)
1341 */
1342 /* convert to ieee library modes */
1343 ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
David Daney515b0292010-10-21 16:32:26 -07001344 sig = cop1Emulate(xcp, ctx, fault_addr);
Ralf Baechlecd21dfc2005-04-28 13:39:10 +00001345 /* revert to mips rounding mode */
1346 ieee754_csr.rm = mips_rm[ieee754_csr.rm];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 }
1348
Atsushi Nemotoe04582b2006-10-09 00:10:01 +09001349 if (has_fpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350 break;
1351 if (sig)
1352 break;
1353
1354 cond_resched();
1355 } while (xcp->cp0_epc > prevepc);
1356
1357 /* SIGILL indicates a non-fpu instruction */
1358 if (sig == SIGILL && xcp->cp0_epc != oldepc)
1359 /* but if epc has advanced, then ignore it */
1360 sig = 0;
1361
1362 return sig;
1363}
Atsushi Nemoto83fd38c2007-07-07 23:21:49 +09001364
1365#ifdef CONFIG_DEBUG_FS
David Daneyb6ee75e2009-11-05 11:34:26 -08001366
1367static int fpuemu_stat_get(void *data, u64 *val)
1368{
1369 int cpu;
1370 unsigned long sum = 0;
1371 for_each_online_cpu(cpu) {
1372 struct mips_fpu_emulator_stats *ps;
1373 local_t *pv;
1374 ps = &per_cpu(fpuemustats, cpu);
1375 pv = (void *)ps + (unsigned long)data;
1376 sum += local_read(pv);
1377 }
1378 *val = sum;
1379 return 0;
1380}
1381DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
1382
Atsushi Nemoto83fd38c2007-07-07 23:21:49 +09001383extern struct dentry *mips_debugfs_dir;
1384static int __init debugfs_fpuemu(void)
1385{
1386 struct dentry *d, *dir;
Atsushi Nemoto83fd38c2007-07-07 23:21:49 +09001387
1388 if (!mips_debugfs_dir)
1389 return -ENODEV;
1390 dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
Zhaoleiecab1f42008-10-17 19:12:30 +08001391 if (!dir)
1392 return -ENOMEM;
David Daneyb6ee75e2009-11-05 11:34:26 -08001393
1394#define FPU_STAT_CREATE(M) \
1395 do { \
1396 d = debugfs_create_file(#M , S_IRUGO, dir, \
1397 (void *)offsetof(struct mips_fpu_emulator_stats, M), \
1398 &fops_fpuemu_stat); \
1399 if (!d) \
1400 return -ENOMEM; \
1401 } while (0)
1402
1403 FPU_STAT_CREATE(emulated);
1404 FPU_STAT_CREATE(loads);
1405 FPU_STAT_CREATE(stores);
1406 FPU_STAT_CREATE(cp1ops);
1407 FPU_STAT_CREATE(cp1xops);
1408 FPU_STAT_CREATE(errors);
1409
Atsushi Nemoto83fd38c2007-07-07 23:21:49 +09001410 return 0;
1411}
1412__initcall(debugfs_fpuemu);
1413#endif