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linux-pinenote/arch/mips/math-emu/cp1emu.c
David Daney 36b0f79b30 MIPS: Remove unreachable break statements from cp1emu.c 
There were many cases of:

   return something;
   break;

All those break statements are unreachable and thus redundant.

Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5727/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-08-26 15:33:40 +02:00

2156 lines
52 KiB
C
Raw Blame History

/*
* cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator
*
* MIPS floating point support
* Copyright (C) 1994-2000 Algorithmics Ltd.
*
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* A complete emulator for MIPS coprocessor 1 instructions. This is
* required for #float(switch) or #float(trap), where it catches all
* COP1 instructions via the "CoProcessor Unusable" exception.
*
* More surprisingly it is also required for #float(ieee), to help out
* the hardware fpu at the boundaries of the IEEE-754 representation
* (denormalised values, infinities, underflow, etc). It is made
* quite nasty because emulation of some non-COP1 instructions is
* required, e.g. in branch delay slots.
*
* Note if you know that you won't have an fpu, then you'll get much
* better performance by compiling with -msoft-float!
*/
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/perf_event.h>
#include <asm/inst.h>
#include <asm/bootinfo.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/signal.h>
#include <asm/mipsregs.h>
#include <asm/fpu_emulator.h>
#include <asm/fpu.h>
#include <asm/uaccess.h>
#include <asm/branch.h>
#include "ieee754.h"
/* Strap kernel emulator for full MIPS IV emulation */
#ifdef __mips
#undef __mips
#endif
#define __mips 4
/* Function which emulates a floating point instruction. */
static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
mips_instruction);
#if __mips >= 4 && __mips != 32
static int fpux_emu(struct pt_regs *,
struct mips_fpu_struct *, mips_instruction, void *__user *);
#endif
/* Further private data for which no space exists in mips_fpu_struct */
#ifdef CONFIG_DEBUG_FS
DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
#endif
/* Control registers */
#define FPCREG_RID 0 /* $0 = revision id */
#define FPCREG_CSR 31 /* $31 = csr */
/* Determine rounding mode from the RM bits of the FCSR */
#define modeindex(v) ((v) & FPU_CSR_RM)
/* microMIPS bitfields */
#define MM_POOL32A_MINOR_MASK 0x3f
#define MM_POOL32A_MINOR_SHIFT 0x6
#define MM_MIPS32_COND_FC 0x30
/* Convert Mips rounding mode (0..3) to IEEE library modes. */
static const unsigned char ieee_rm[4] = {
[FPU_CSR_RN] = IEEE754_RN,
[FPU_CSR_RZ] = IEEE754_RZ,
[FPU_CSR_RU] = IEEE754_RU,
[FPU_CSR_RD] = IEEE754_RD,
};
/* Convert IEEE library modes to Mips rounding mode (0..3). */
static const unsigned char mips_rm[4] = {
[IEEE754_RN] = FPU_CSR_RN,
[IEEE754_RZ] = FPU_CSR_RZ,
[IEEE754_RD] = FPU_CSR_RD,
[IEEE754_RU] = FPU_CSR_RU,
};
#if __mips >= 4
/* convert condition code register number to csr bit */
static const unsigned int fpucondbit[8] = {
FPU_CSR_COND0,
FPU_CSR_COND1,
FPU_CSR_COND2,
FPU_CSR_COND3,
FPU_CSR_COND4,
FPU_CSR_COND5,
FPU_CSR_COND6,
FPU_CSR_COND7
};
#endif
/* (microMIPS) Convert 16-bit register encoding to 32-bit register encoding. */
static const unsigned int reg16to32map[8] = {16, 17, 2, 3, 4, 5, 6, 7};
/* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */
static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0};
static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0};
static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0};
static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0};
/*
* This functions translates a 32-bit microMIPS instruction
* into a 32-bit MIPS32 instruction. Returns 0 on success
* and SIGILL otherwise.
*/
static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr)
{
union mips_instruction insn = *insn_ptr;
union mips_instruction mips32_insn = insn;
int func, fmt, op;
switch (insn.mm_i_format.opcode) {
case mm_ldc132_op:
mips32_insn.mm_i_format.opcode = ldc1_op;
mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
break;
case mm_lwc132_op:
mips32_insn.mm_i_format.opcode = lwc1_op;
mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
break;
case mm_sdc132_op:
mips32_insn.mm_i_format.opcode = sdc1_op;
mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
break;
case mm_swc132_op:
mips32_insn.mm_i_format.opcode = swc1_op;
mips32_insn.mm_i_format.rt = insn.mm_i_format.rs;
mips32_insn.mm_i_format.rs = insn.mm_i_format.rt;
break;
case mm_pool32i_op:
/* NOTE: offset is << by 1 if in microMIPS mode. */
if ((insn.mm_i_format.rt == mm_bc1f_op) ||
(insn.mm_i_format.rt == mm_bc1t_op)) {
mips32_insn.fb_format.opcode = cop1_op;
mips32_insn.fb_format.bc = bc_op;
mips32_insn.fb_format.flag =
(insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0;
} else
return SIGILL;
break;
case mm_pool32f_op:
switch (insn.mm_fp0_format.func) {
case mm_32f_01_op:
case mm_32f_11_op:
case mm_32f_02_op:
case mm_32f_12_op:
case mm_32f_41_op:
case mm_32f_51_op:
case mm_32f_42_op:
case mm_32f_52_op:
op = insn.mm_fp0_format.func;
if (op == mm_32f_01_op)
func = madd_s_op;
else if (op == mm_32f_11_op)
func = madd_d_op;
else if (op == mm_32f_02_op)
func = nmadd_s_op;
else if (op == mm_32f_12_op)
func = nmadd_d_op;
else if (op == mm_32f_41_op)
func = msub_s_op;
else if (op == mm_32f_51_op)
func = msub_d_op;
else if (op == mm_32f_42_op)
func = nmsub_s_op;
else
func = nmsub_d_op;
mips32_insn.fp6_format.opcode = cop1x_op;
mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr;
mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft;
mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs;
mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd;
mips32_insn.fp6_format.func = func;
break;
case mm_32f_10_op:
func = -1; /* Invalid */
op = insn.mm_fp5_format.op & 0x7;
if (op == mm_ldxc1_op)
func = ldxc1_op;
else if (op == mm_sdxc1_op)
func = sdxc1_op;
else if (op == mm_lwxc1_op)
func = lwxc1_op;
else if (op == mm_swxc1_op)
func = swxc1_op;
if (func != -1) {
mips32_insn.r_format.opcode = cop1x_op;
mips32_insn.r_format.rs =
insn.mm_fp5_format.base;
mips32_insn.r_format.rt =
insn.mm_fp5_format.index;
mips32_insn.r_format.rd = 0;
mips32_insn.r_format.re = insn.mm_fp5_format.fd;
mips32_insn.r_format.func = func;
} else
return SIGILL;
break;
case mm_32f_40_op:
op = -1; /* Invalid */
if (insn.mm_fp2_format.op == mm_fmovt_op)
op = 1;
else if (insn.mm_fp2_format.op == mm_fmovf_op)
op = 0;
if (op != -1) {
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp2_format.fmt];
mips32_insn.fp0_format.ft =
(insn.mm_fp2_format.cc<<2) + op;
mips32_insn.fp0_format.fs =
insn.mm_fp2_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp2_format.fd;
mips32_insn.fp0_format.func = fmovc_op;
} else
return SIGILL;
break;
case mm_32f_60_op:
func = -1; /* Invalid */
if (insn.mm_fp0_format.op == mm_fadd_op)
func = fadd_op;
else if (insn.mm_fp0_format.op == mm_fsub_op)
func = fsub_op;
else if (insn.mm_fp0_format.op == mm_fmul_op)
func = fmul_op;
else if (insn.mm_fp0_format.op == mm_fdiv_op)
func = fdiv_op;
if (func != -1) {
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp0_format.fmt];
mips32_insn.fp0_format.ft =
insn.mm_fp0_format.ft;
mips32_insn.fp0_format.fs =
insn.mm_fp0_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp0_format.fd;
mips32_insn.fp0_format.func = func;
} else
return SIGILL;
break;
case mm_32f_70_op:
func = -1; /* Invalid */
if (insn.mm_fp0_format.op == mm_fmovn_op)
func = fmovn_op;
else if (insn.mm_fp0_format.op == mm_fmovz_op)
func = fmovz_op;
if (func != -1) {
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp0_format.fmt];
mips32_insn.fp0_format.ft =
insn.mm_fp0_format.ft;
mips32_insn.fp0_format.fs =
insn.mm_fp0_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp0_format.fd;
mips32_insn.fp0_format.func = func;
} else
return SIGILL;
break;
case mm_32f_73_op: /* POOL32FXF */
switch (insn.mm_fp1_format.op) {
case mm_movf0_op:
case mm_movf1_op:
case mm_movt0_op:
case mm_movt1_op:
if ((insn.mm_fp1_format.op & 0x7f) ==
mm_movf0_op)
op = 0;
else
op = 1;
mips32_insn.r_format.opcode = spec_op;
mips32_insn.r_format.rs = insn.mm_fp4_format.fs;
mips32_insn.r_format.rt =
(insn.mm_fp4_format.cc << 2) + op;
mips32_insn.r_format.rd = insn.mm_fp4_format.rt;
mips32_insn.r_format.re = 0;
mips32_insn.r_format.func = movc_op;
break;
case mm_fcvtd0_op:
case mm_fcvtd1_op:
case mm_fcvts0_op:
case mm_fcvts1_op:
if ((insn.mm_fp1_format.op & 0x7f) ==
mm_fcvtd0_op) {
func = fcvtd_op;
fmt = swl_format[insn.mm_fp3_format.fmt];
} else {
func = fcvts_op;
fmt = dwl_format[insn.mm_fp3_format.fmt];
}
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt = fmt;
mips32_insn.fp0_format.ft = 0;
mips32_insn.fp0_format.fs =
insn.mm_fp3_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp3_format.rt;
mips32_insn.fp0_format.func = func;
break;
case mm_fmov0_op:
case mm_fmov1_op:
case mm_fabs0_op:
case mm_fabs1_op:
case mm_fneg0_op:
case mm_fneg1_op:
if ((insn.mm_fp1_format.op & 0x7f) ==
mm_fmov0_op)
func = fmov_op;
else if ((insn.mm_fp1_format.op & 0x7f) ==
mm_fabs0_op)
func = fabs_op;
else
func = fneg_op;
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp3_format.fmt];
mips32_insn.fp0_format.ft = 0;
mips32_insn.fp0_format.fs =
insn.mm_fp3_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp3_format.rt;
mips32_insn.fp0_format.func = func;
break;
case mm_ffloorl_op:
case mm_ffloorw_op:
case mm_fceill_op:
case mm_fceilw_op:
case mm_ftruncl_op:
case mm_ftruncw_op:
case mm_froundl_op:
case mm_froundw_op:
case mm_fcvtl_op:
case mm_fcvtw_op:
if (insn.mm_fp1_format.op == mm_ffloorl_op)
func = ffloorl_op;
else if (insn.mm_fp1_format.op == mm_ffloorw_op)
func = ffloor_op;
else if (insn.mm_fp1_format.op == mm_fceill_op)
func = fceill_op;
else if (insn.mm_fp1_format.op == mm_fceilw_op)
func = fceil_op;
else if (insn.mm_fp1_format.op == mm_ftruncl_op)
func = ftruncl_op;
else if (insn.mm_fp1_format.op == mm_ftruncw_op)
func = ftrunc_op;
else if (insn.mm_fp1_format.op == mm_froundl_op)
func = froundl_op;
else if (insn.mm_fp1_format.op == mm_froundw_op)
func = fround_op;
else if (insn.mm_fp1_format.op == mm_fcvtl_op)
func = fcvtl_op;
else
func = fcvtw_op;
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sd_format[insn.mm_fp1_format.fmt];
mips32_insn.fp0_format.ft = 0;
mips32_insn.fp0_format.fs =
insn.mm_fp1_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp1_format.rt;
mips32_insn.fp0_format.func = func;
break;
case mm_frsqrt_op:
case mm_fsqrt_op:
case mm_frecip_op:
if (insn.mm_fp1_format.op == mm_frsqrt_op)
func = frsqrt_op;
else if (insn.mm_fp1_format.op == mm_fsqrt_op)
func = fsqrt_op;
else
func = frecip_op;
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp1_format.fmt];
mips32_insn.fp0_format.ft = 0;
mips32_insn.fp0_format.fs =
insn.mm_fp1_format.fs;
mips32_insn.fp0_format.fd =
insn.mm_fp1_format.rt;
mips32_insn.fp0_format.func = func;
break;
case mm_mfc1_op:
case mm_mtc1_op:
case mm_cfc1_op:
case mm_ctc1_op:
if (insn.mm_fp1_format.op == mm_mfc1_op)
op = mfc_op;
else if (insn.mm_fp1_format.op == mm_mtc1_op)
op = mtc_op;
else if (insn.mm_fp1_format.op == mm_cfc1_op)
op = cfc_op;
else
op = ctc_op;
mips32_insn.fp1_format.opcode = cop1_op;
mips32_insn.fp1_format.op = op;
mips32_insn.fp1_format.rt =
insn.mm_fp1_format.rt;
mips32_insn.fp1_format.fs =
insn.mm_fp1_format.fs;
mips32_insn.fp1_format.fd = 0;
mips32_insn.fp1_format.func = 0;
break;
default:
return SIGILL;
}
break;
case mm_32f_74_op: /* c.cond.fmt */
mips32_insn.fp0_format.opcode = cop1_op;
mips32_insn.fp0_format.fmt =
sdps_format[insn.mm_fp4_format.fmt];
mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt;
mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs;
mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2;
mips32_insn.fp0_format.func =
insn.mm_fp4_format.cond | MM_MIPS32_COND_FC;
break;
default:
return SIGILL;
}
break;
default:
return SIGILL;
}
*insn_ptr = mips32_insn;
return 0;
}
int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
unsigned long *contpc)
{
union mips_instruction insn = (union mips_instruction)dec_insn.insn;
int bc_false = 0;
unsigned int fcr31;
unsigned int bit;
if (!cpu_has_mmips)
return 0;
switch (insn.mm_i_format.opcode) {
case mm_pool32a_op:
if ((insn.mm_i_format.simmediate & MM_POOL32A_MINOR_MASK) ==
mm_pool32axf_op) {
switch (insn.mm_i_format.simmediate >>
MM_POOL32A_MINOR_SHIFT) {
case mm_jalr_op:
case mm_jalrhb_op:
case mm_jalrs_op:
case mm_jalrshb_op:
if (insn.mm_i_format.rt != 0) /* Not mm_jr */
regs->regs[insn.mm_i_format.rt] =
regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
*contpc = regs->regs[insn.mm_i_format.rs];
return 1;
}
}
break;
case mm_pool32i_op:
switch (insn.mm_i_format.rt) {
case mm_bltzals_op:
case mm_bltzal_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case mm_bltz_op:
if ((long)regs->regs[insn.mm_i_format.rs] < 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case mm_bgezals_op:
case mm_bgezal_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case mm_bgez_op:
if ((long)regs->regs[insn.mm_i_format.rs] >= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case mm_blez_op:
if ((long)regs->regs[insn.mm_i_format.rs] <= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case mm_bgtz_op:
if ((long)regs->regs[insn.mm_i_format.rs] <= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case mm_bc2f_op:
case mm_bc1f_op:
bc_false = 1;
/* Fall through */
case mm_bc2t_op:
case mm_bc1t_op:
preempt_disable();
if (is_fpu_owner())
asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
if (bc_false)
fcr31 = ~fcr31;
bit = (insn.mm_i_format.rs >> 2);
bit += (bit != 0);
bit += 23;
if (fcr31 & (1 << bit))
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
return 1;
}
break;
case mm_pool16c_op:
switch (insn.mm_i_format.rt) {
case mm_jalr16_op:
case mm_jalrs16_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
/* Fall through */
case mm_jr16_op:
*contpc = regs->regs[insn.mm_i_format.rs];
return 1;
}
break;
case mm_beqz16_op:
if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] == 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_b1_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
return 1;
case mm_bnez16_op:
if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] != 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_b1_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
return 1;
case mm_b16_op:
*contpc = regs->cp0_epc + dec_insn.pc_inc +
(insn.mm_b0_format.simmediate << 1);
return 1;
case mm_beq32_op:
if (regs->regs[insn.mm_i_format.rs] ==
regs->regs[insn.mm_i_format.rt])
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case mm_bne32_op:
if (regs->regs[insn.mm_i_format.rs] !=
regs->regs[insn.mm_i_format.rt])
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.mm_i_format.simmediate << 1);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
return 1;
case mm_jalx32_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
*contpc = regs->cp0_epc + dec_insn.pc_inc;
*contpc >>= 28;
*contpc <<= 28;
*contpc |= (insn.j_format.target << 2);
return 1;
case mm_jals32_op:
case mm_jal32_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc + dec_insn.next_pc_inc;
/* Fall through */
case mm_j32_op:
*contpc = regs->cp0_epc + dec_insn.pc_inc;
*contpc >>= 27;
*contpc <<= 27;
*contpc |= (insn.j_format.target << 1);
set_isa16_mode(*contpc);
return 1;
}
return 0;
}
/*
* Redundant with logic already in kernel/branch.c,
* embedded in compute_return_epc. At some point,
* a single subroutine should be used across both
* modules.
*/
static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
unsigned long *contpc)
{
union mips_instruction insn = (union mips_instruction)dec_insn.insn;
unsigned int fcr31;
unsigned int bit = 0;
switch (insn.i_format.opcode) {
case spec_op:
switch (insn.r_format.func) {
case jalr_op:
regs->regs[insn.r_format.rd] =
regs->cp0_epc + dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case jr_op:
*contpc = regs->regs[insn.r_format.rs];
return 1;
}
break;
case bcond_op:
switch (insn.i_format.rt) {
case bltzal_op:
case bltzall_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case bltz_op:
case bltzl_op:
if ((long)regs->regs[insn.i_format.rs] < 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case bgezal_op:
case bgezall_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case bgez_op:
case bgezl_op:
if ((long)regs->regs[insn.i_format.rs] >= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
}
break;
case jalx_op:
set_isa16_mode(bit);
case jal_op:
regs->regs[31] = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
/* Fall through */
case j_op:
*contpc = regs->cp0_epc + dec_insn.pc_inc;
*contpc >>= 28;
*contpc <<= 28;
*contpc |= (insn.j_format.target << 2);
/* Set microMIPS mode bit: XOR for jalx. */
*contpc ^= bit;
return 1;
case beq_op:
case beql_op:
if (regs->regs[insn.i_format.rs] ==
regs->regs[insn.i_format.rt])
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case bne_op:
case bnel_op:
if (regs->regs[insn.i_format.rs] !=
regs->regs[insn.i_format.rt])
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case blez_op:
case blezl_op:
if ((long)regs->regs[insn.i_format.rs] <= 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case bgtz_op:
case bgtzl_op:
if ((long)regs->regs[insn.i_format.rs] > 0)
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
#ifdef CONFIG_CPU_CAVIUM_OCTEON
case lwc2_op: /* This is bbit0 on Octeon */
if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) == 0)
*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc + 8;
return 1;
case ldc2_op: /* This is bbit032 on Octeon */
if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0)
*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc + 8;
return 1;
case swc2_op: /* This is bbit1 on Octeon */
if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt))
*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc + 8;
return 1;
case sdc2_op: /* This is bbit132 on Octeon */
if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32)))
*contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc + 8;
return 1;
#endif
case cop0_op:
case cop1_op:
case cop2_op:
case cop1x_op:
if (insn.i_format.rs == bc_op) {
preempt_disable();
if (is_fpu_owner())
asm volatile("cfc1\t%0,$31" : "=r" (fcr31));
else
fcr31 = current->thread.fpu.fcr31;
preempt_enable();
bit = (insn.i_format.rt >> 2);
bit += (bit != 0);
bit += 23;
switch (insn.i_format.rt & 3) {
case 0: /* bc1f */
case 2: /* bc1fl */
if (~fcr31 & (1 << bit))
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
case 1: /* bc1t */
case 3: /* bc1tl */
if (fcr31 & (1 << bit))
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
(insn.i_format.simmediate << 2);
else
*contpc = regs->cp0_epc +
dec_insn.pc_inc +
dec_insn.next_pc_inc;
return 1;
}
}
break;
}
return 0;
}
/*
* In the Linux kernel, we support selection of FPR format on the
* basis of the Status.FR bit. If an FPU is not present, the FR bit
* is hardwired to zero, which would imply a 32-bit FPU even for
* 64-bit CPUs so we rather look at TIF_32BIT_REGS.
* FPU emu is slow and bulky and optimizing this function offers fairly
* sizeable benefits so we try to be clever and make this function return
* a constant whenever possible, that is on 64-bit kernels without O32
* compatibility enabled and on 32-bit kernels.
*/
static inline int cop1_64bit(struct pt_regs *xcp)
{
#if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32)
return 1;
#elif defined(CONFIG_64BIT) && defined(CONFIG_MIPS32_O32)
return !test_thread_flag(TIF_32BIT_REGS);
#else
return 0;
#endif
}
#define SIFROMREG(si, x) ((si) = cop1_64bit(xcp) || !(x & 1) ? \
(int)ctx->fpr[x] : (int)(ctx->fpr[x & ~1] >> 32))
#define SITOREG(si, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = \
cop1_64bit(xcp) || !(x & 1) ? \
ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \
ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32)
#define DIFROMREG(di, x) ((di) = ctx->fpr[x & ~(cop1_64bit(xcp) == 0)])
#define DITOREG(di, x) (ctx->fpr[x & ~(cop1_64bit(xcp) == 0)] = (di))
#define SPFROMREG(sp, x) SIFROMREG((sp).bits, x)
#define SPTOREG(sp, x) SITOREG((sp).bits, x)
#define DPFROMREG(dp, x) DIFROMREG((dp).bits, x)
#define DPTOREG(dp, x) DITOREG((dp).bits, x)
/*
* Emulate the single floating point instruction pointed at by EPC.
* Two instructions if the instruction is in a branch delay slot.
*/
static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
struct mm_decoded_insn dec_insn, void *__user *fault_addr)
{
mips_instruction ir;
unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
unsigned int cond;
int pc_inc;
/* XXX NEC Vr54xx bug workaround */
if (xcp->cp0_cause & CAUSEF_BD) {
if (dec_insn.micro_mips_mode) {
if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
xcp->cp0_cause &= ~CAUSEF_BD;
} else {
if (!isBranchInstr(xcp, dec_insn, &contpc))
xcp->cp0_cause &= ~CAUSEF_BD;
}
}
if (xcp->cp0_cause & CAUSEF_BD) {
/*
* The instruction to be emulated is in a branch delay slot
* which means that we have to emulate the branch instruction
* BEFORE we do the cop1 instruction.
*
* This branch could be a COP1 branch, but in that case we
* would have had a trap for that instruction, and would not
* come through this route.
*
* Linux MIPS branch emulator operates on context, updating the
* cp0_epc.
*/
ir = dec_insn.next_insn; /* process delay slot instr */
pc_inc = dec_insn.next_pc_inc;
} else {
ir = dec_insn.insn; /* process current instr */
pc_inc = dec_insn.pc_inc;
}
/*
* Since microMIPS FPU instructios are a subset of MIPS32 FPU
* instructions, we want to convert microMIPS FPU instructions
* into MIPS32 instructions so that we could reuse all of the
* FPU emulation code.
*
* NOTE: We cannot do this for branch instructions since they
* are not a subset. Example: Cannot emulate a 16-bit
* aligned target address with a MIPS32 instruction.
*/
if (dec_insn.micro_mips_mode) {
/*
* If next instruction is a 16-bit instruction, then it
* it cannot be a FPU instruction. This could happen
* since we can be called for non-FPU instructions.
*/
if ((pc_inc == 2) ||
(microMIPS32_to_MIPS32((union mips_instruction *)&ir)
== SIGILL))
return SIGILL;
}
emul:
perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0);
MIPS_FPU_EMU_INC_STATS(emulated);
switch (MIPSInst_OPCODE(ir)) {
case ldc1_op:{
u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
u64 val;
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__get_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
DITOREG(val, MIPSInst_RT(ir));
break;
}
case sdc1_op:{
u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
u64 val;
MIPS_FPU_EMU_INC_STATS(stores);
DIFROMREG(val, MIPSInst_RT(ir));
if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__put_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
break;
}
case lwc1_op:{
u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
u32 val;
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__get_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
SITOREG(val, MIPSInst_RT(ir));
break;
}
case swc1_op:{
u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
u32 val;
MIPS_FPU_EMU_INC_STATS(stores);
SIFROMREG(val, MIPSInst_RT(ir));
if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__put_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
break;
}
case cop1_op:
switch (MIPSInst_RS(ir)) {
#if defined(__mips64)
case dmfc_op:
/* copregister fs -> gpr[rt] */
if (MIPSInst_RT(ir) != 0) {
DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
MIPSInst_RD(ir));
}
break;
case dmtc_op:
/* copregister fs <- rt */
DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
break;
#endif
case mfc_op:
/* copregister rd -> gpr[rt] */
if (MIPSInst_RT(ir) != 0) {
SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
MIPSInst_RD(ir));
}
break;
case mtc_op:
/* copregister rd <- rt */
SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
break;
case cfc_op:{
/* cop control register rd -> gpr[rt] */
u32 value;
if (MIPSInst_RD(ir) == FPCREG_CSR) {
value = ctx->fcr31;
value = (value & ~FPU_CSR_RM) |
mips_rm[modeindex(value)];
#ifdef CSRTRACE
printk("%p gpr[%d]<-csr=%08x\n",
(void *) (xcp->cp0_epc),
MIPSInst_RT(ir), value);
#endif
}
else if (MIPSInst_RD(ir) == FPCREG_RID)
value = 0;
else
value = 0;
if (MIPSInst_RT(ir))
xcp->regs[MIPSInst_RT(ir)] = value;
break;
}
case ctc_op:{
/* copregister rd <- rt */
u32 value;
if (MIPSInst_RT(ir) == 0)
value = 0;
else
value = xcp->regs[MIPSInst_RT(ir)];
/* we only have one writable control reg
*/
if (MIPSInst_RD(ir) == FPCREG_CSR) {
#ifdef CSRTRACE
printk("%p gpr[%d]->csr=%08x\n",
(void *) (xcp->cp0_epc),
MIPSInst_RT(ir), value);
#endif
/*
* Don't write reserved bits,
* and convert to ieee library modes
*/
ctx->fcr31 = (value &
~(FPU_CSR_RSVD | FPU_CSR_RM)) |
ieee_rm[modeindex(value)];
}
if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
return SIGFPE;
}
break;
}
case bc_op:{
int likely = 0;
if (xcp->cp0_cause & CAUSEF_BD)
return SIGILL;
#if __mips >= 4
cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2];
#else
cond = ctx->fcr31 & FPU_CSR_COND;
#endif
switch (MIPSInst_RT(ir) & 3) {
case bcfl_op:
likely = 1;
case bcf_op:
cond = !cond;
break;
case bctl_op:
likely = 1;
case bct_op:
break;
default:
/* thats an illegal instruction */
return SIGILL;
}
xcp->cp0_cause |= CAUSEF_BD;
if (cond) {
/* branch taken: emulate dslot
* instruction
*/
xcp->cp0_epc += dec_insn.pc_inc;
contpc = MIPSInst_SIMM(ir);
ir = dec_insn.next_insn;
if (dec_insn.micro_mips_mode) {
contpc = (xcp->cp0_epc + (contpc << 1));
/* If 16-bit instruction, not FPU. */
if ((dec_insn.next_pc_inc == 2) ||
(microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) {
/*
* Since this instruction will
* be put on the stack with
* 32-bit words, get around
* this problem by putting a
* NOP16 as the second one.
*/
if (dec_insn.next_pc_inc == 2)
ir = (ir & (~0xffff)) | MM_NOP16;
/*
* Single step the non-CP1
* instruction in the dslot.
*/
return mips_dsemul(xcp, ir, contpc);
}
} else
contpc = (xcp->cp0_epc + (contpc << 2));
switch (MIPSInst_OPCODE(ir)) {
case lwc1_op:
case swc1_op:
#if (__mips >= 2 || defined(__mips64))
case ldc1_op:
case sdc1_op:
#endif
case cop1_op:
#if __mips >= 4 && __mips != 32
case cop1x_op:
#endif
/* its one of ours */
goto emul;
#if __mips >= 4
case spec_op:
if (MIPSInst_FUNC(ir) == movc_op)
goto emul;
break;
#endif
}
/*
* Single step the non-cp1
* instruction in the dslot
*/
return mips_dsemul(xcp, ir, contpc);
}
else {
/* branch not taken */
if (likely) {
/*
* branch likely nullifies
* dslot if not taken
*/
xcp->cp0_epc += dec_insn.pc_inc;
contpc += dec_insn.pc_inc;
/*
* else continue & execute
* dslot as normal insn
*/
}
}
break;
}
default:
if (!(MIPSInst_RS(ir) & 0x10))
return SIGILL;
{
int sig;
/* a real fpu computation instruction */
if ((sig = fpu_emu(xcp, ctx, ir)))
return sig;
}
}
break;
#if __mips >= 4 && __mips != 32
case cop1x_op:{
int sig = fpux_emu(xcp, ctx, ir, fault_addr);
if (sig)
return sig;
break;
}
#endif
#if __mips >= 4
case spec_op:
if (MIPSInst_FUNC(ir) != movc_op)
return SIGILL;
cond = fpucondbit[MIPSInst_RT(ir) >> 2];
if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0))
xcp->regs[MIPSInst_RD(ir)] =
xcp->regs[MIPSInst_RS(ir)];
break;
#endif
default:
return SIGILL;
}
/* we did it !! */
xcp->cp0_epc = contpc;
xcp->cp0_cause &= ~CAUSEF_BD;
return 0;
}
/*
* Conversion table from MIPS compare ops 48-63
* cond = ieee754dp_cmp(x,y,IEEE754_UN,sig);
*/
static const unsigned char cmptab[8] = {
0, /* cmp_0 (sig) cmp_sf */
IEEE754_CUN, /* cmp_un (sig) cmp_ngle */
IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */
IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */
IEEE754_CLT, /* cmp_olt (sig) cmp_lt */
IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */
IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */
IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */
};
#if __mips >= 4 && __mips != 32
/*
* Additional MIPS4 instructions
*/
#define DEF3OP(name, p, f1, f2, f3) \
static ieee754##p fpemu_##p##_##name(ieee754##p r, ieee754##p s, \
ieee754##p t) \
{ \
struct _ieee754_csr ieee754_csr_save; \
s = f1(s, t); \
ieee754_csr_save = ieee754_csr; \
s = f2(s, r); \
ieee754_csr_save.cx |= ieee754_csr.cx; \
ieee754_csr_save.sx |= ieee754_csr.sx; \
s = f3(s); \
ieee754_csr.cx |= ieee754_csr_save.cx; \
ieee754_csr.sx |= ieee754_csr_save.sx; \
return s; \
}
static ieee754dp fpemu_dp_recip(ieee754dp d)
{
return ieee754dp_div(ieee754dp_one(0), d);
}
static ieee754dp fpemu_dp_rsqrt(ieee754dp d)
{
return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
}
static ieee754sp fpemu_sp_recip(ieee754sp s)
{
return ieee754sp_div(ieee754sp_one(0), s);
}
static ieee754sp fpemu_sp_rsqrt(ieee754sp s)
{
return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s));
}
DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add, );
DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub, );
DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg);
DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg);
DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add, );
DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub, );
DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
mips_instruction ir, void *__user *fault_addr)
{
unsigned rcsr = 0; /* resulting csr */
MIPS_FPU_EMU_INC_STATS(cp1xops);
switch (MIPSInst_FMA_FFMT(ir)) {
case s_fmt:{ /* 0 */
ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
ieee754sp fd, fr, fs, ft;
u32 __user *va;
u32 val;
switch (MIPSInst_FUNC(ir)) {
case lwxc1_op:
va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
xcp->regs[MIPSInst_FT(ir)]);
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, va, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__get_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
SITOREG(val, MIPSInst_FD(ir));
break;
case swxc1_op:
va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
xcp->regs[MIPSInst_FT(ir)]);
MIPS_FPU_EMU_INC_STATS(stores);
SIFROMREG(val, MIPSInst_FS(ir));
if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (put_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
break;
case madd_s_op:
handler = fpemu_sp_madd;
goto scoptop;
case msub_s_op:
handler = fpemu_sp_msub;
goto scoptop;
case nmadd_s_op:
handler = fpemu_sp_nmadd;
goto scoptop;
case nmsub_s_op:
handler = fpemu_sp_nmsub;
goto scoptop;
scoptop:
SPFROMREG(fr, MIPSInst_FR(ir));
SPFROMREG(fs, MIPSInst_FS(ir));
SPFROMREG(ft, MIPSInst_FT(ir));
fd = (*handler) (fr, fs, ft);
SPTOREG(fd, MIPSInst_FD(ir));
copcsr:
if (ieee754_cxtest(IEEE754_INEXACT))
rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
if (ieee754_cxtest(IEEE754_UNDERFLOW))
rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
if (ieee754_cxtest(IEEE754_OVERFLOW))
rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
/*printk ("SIGFPE: fpu csr = %08x\n",
ctx->fcr31); */
return SIGFPE;
}
break;
default:
return SIGILL;
}
break;
}
case d_fmt:{ /* 1 */
ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
ieee754dp fd, fr, fs, ft;
u64 __user *va;
u64 val;
switch (MIPSInst_FUNC(ir)) {
case ldxc1_op:
va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
xcp->regs[MIPSInst_FT(ir)]);
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, va, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__get_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
DITOREG(val, MIPSInst_FD(ir));
break;
case sdxc1_op:
va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] +
xcp->regs[MIPSInst_FT(ir)]);
MIPS_FPU_EMU_INC_STATS(stores);
DIFROMREG(val, MIPSInst_FS(ir));
if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGBUS;
}
if (__put_user(val, va)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = va;
return SIGSEGV;
}
break;
case madd_d_op:
handler = fpemu_dp_madd;
goto dcoptop;
case msub_d_op:
handler = fpemu_dp_msub;
goto dcoptop;
case nmadd_d_op:
handler = fpemu_dp_nmadd;
goto dcoptop;
case nmsub_d_op:
handler = fpemu_dp_nmsub;
goto dcoptop;
dcoptop:
DPFROMREG(fr, MIPSInst_FR(ir));
DPFROMREG(fs, MIPSInst_FS(ir));
DPFROMREG(ft, MIPSInst_FT(ir));
fd = (*handler) (fr, fs, ft);
DPTOREG(fd, MIPSInst_FD(ir));
goto copcsr;
default:
return SIGILL;
}
break;
}
case 0x7: /* 7 */
if (MIPSInst_FUNC(ir) != pfetch_op) {
return SIGILL;
}
/* ignore prefx operation */
break;
default:
return SIGILL;
}
return 0;
}
#endif
/*
* Emulate a single COP1 arithmetic instruction.
*/
static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
mips_instruction ir)
{
int rfmt; /* resulting format */
unsigned rcsr = 0; /* resulting csr */
unsigned cond;
union {
ieee754dp d;
ieee754sp s;
int w;
#ifdef __mips64
s64 l;
#endif
} rv; /* resulting value */
MIPS_FPU_EMU_INC_STATS(cp1ops);
switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
case s_fmt:{ /* 0 */
union {
ieee754sp(*b) (ieee754sp, ieee754sp);
ieee754sp(*u) (ieee754sp);
} handler;
switch (MIPSInst_FUNC(ir)) {
/* binary ops */
case fadd_op:
handler.b = ieee754sp_add;
goto scopbop;
case fsub_op:
handler.b = ieee754sp_sub;
goto scopbop;
case fmul_op:
handler.b = ieee754sp_mul;
goto scopbop;
case fdiv_op:
handler.b = ieee754sp_div;
goto scopbop;
/* unary ops */
#if __mips >= 2 || defined(__mips64)
case fsqrt_op:
handler.u = ieee754sp_sqrt;
goto scopuop;
#endif
#if __mips >= 4 && __mips != 32
case frsqrt_op:
handler.u = fpemu_sp_rsqrt;
goto scopuop;
case frecip_op:
handler.u = fpemu_sp_recip;
goto scopuop;
#endif
#if __mips >= 4
case fmovc_op:
cond = fpucondbit[MIPSInst_FT(ir) >> 2];
if (((ctx->fcr31 & cond) != 0) !=
((MIPSInst_FT(ir) & 1) != 0))
return 0;
SPFROMREG(rv.s, MIPSInst_FS(ir));
break;
case fmovz_op:
if (xcp->regs[MIPSInst_FT(ir)] != 0)
return 0;
SPFROMREG(rv.s, MIPSInst_FS(ir));
break;
case fmovn_op:
if (xcp->regs[MIPSInst_FT(ir)] == 0)
return 0;
SPFROMREG(rv.s, MIPSInst_FS(ir));
break;
#endif
case fabs_op:
handler.u = ieee754sp_abs;
goto scopuop;
case fneg_op:
handler.u = ieee754sp_neg;
goto scopuop;
case fmov_op:
/* an easy one */
SPFROMREG(rv.s, MIPSInst_FS(ir));
goto copcsr;
/* binary op on handler */
scopbop:
{
ieee754sp fs, ft;
SPFROMREG(fs, MIPSInst_FS(ir));
SPFROMREG(ft, MIPSInst_FT(ir));
rv.s = (*handler.b) (fs, ft);
goto copcsr;
}
scopuop:
{
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
rv.s = (*handler.u) (fs);
goto copcsr;
}
copcsr:
if (ieee754_cxtest(IEEE754_INEXACT))
rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S;
if (ieee754_cxtest(IEEE754_UNDERFLOW))
rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S;
if (ieee754_cxtest(IEEE754_OVERFLOW))
rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S;
if (ieee754_cxtest(IEEE754_ZERO_DIVIDE))
rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S;
if (ieee754_cxtest(IEEE754_INVALID_OPERATION))
rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S;
break;
/* unary conv ops */
case fcvts_op:
return SIGILL; /* not defined */
case fcvtd_op:{
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
rv.d = ieee754dp_fsp(fs);
rfmt = d_fmt;
goto copcsr;
}
case fcvtw_op:{
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
rv.w = ieee754sp_tint(fs);
rfmt = w_fmt;
goto copcsr;
}
#if __mips >= 2 || defined(__mips64)
case fround_op:
case ftrunc_op:
case fceil_op:
case ffloor_op:{
unsigned int oldrm = ieee754_csr.rm;
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
rv.w = ieee754sp_tint(fs);
ieee754_csr.rm = oldrm;
rfmt = w_fmt;
goto copcsr;
}
#endif /* __mips >= 2 */
#if defined(__mips64)
case fcvtl_op:{
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
rv.l = ieee754sp_tlong(fs);
rfmt = l_fmt;
goto copcsr;
}
case froundl_op:
case ftruncl_op:
case fceill_op:
case ffloorl_op:{
unsigned int oldrm = ieee754_csr.rm;
ieee754sp fs;
SPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
rv.l = ieee754sp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
goto copcsr;
}
#endif /* defined(__mips64) */
default:
if (MIPSInst_FUNC(ir) >= fcmp_op) {
unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
ieee754sp fs, ft;
SPFROMREG(fs, MIPSInst_FS(ir));
SPFROMREG(ft, MIPSInst_FT(ir));
rv.w = ieee754sp_cmp(fs, ft,
cmptab[cmpop & 0x7], cmpop & 0x8);
rfmt = -1;
if ((cmpop & 0x8) && ieee754_cxtest
(IEEE754_INVALID_OPERATION))
rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
else
goto copcsr;
}
else {
return SIGILL;
}
break;
}
break;
}
case d_fmt:{
union {
ieee754dp(*b) (ieee754dp, ieee754dp);
ieee754dp(*u) (ieee754dp);
} handler;
switch (MIPSInst_FUNC(ir)) {
/* binary ops */
case fadd_op:
handler.b = ieee754dp_add;
goto dcopbop;
case fsub_op:
handler.b = ieee754dp_sub;
goto dcopbop;
case fmul_op:
handler.b = ieee754dp_mul;
goto dcopbop;
case fdiv_op:
handler.b = ieee754dp_div;
goto dcopbop;
/* unary ops */
#if __mips >= 2 || defined(__mips64)
case fsqrt_op:
handler.u = ieee754dp_sqrt;
goto dcopuop;
#endif
#if __mips >= 4 && __mips != 32
case frsqrt_op:
handler.u = fpemu_dp_rsqrt;
goto dcopuop;
case frecip_op:
handler.u = fpemu_dp_recip;
goto dcopuop;
#endif
#if __mips >= 4
case fmovc_op:
cond = fpucondbit[MIPSInst_FT(ir) >> 2];
if (((ctx->fcr31 & cond) != 0) !=
((MIPSInst_FT(ir) & 1) != 0))
return 0;
DPFROMREG(rv.d, MIPSInst_FS(ir));
break;
case fmovz_op:
if (xcp->regs[MIPSInst_FT(ir)] != 0)
return 0;
DPFROMREG(rv.d, MIPSInst_FS(ir));
break;
case fmovn_op:
if (xcp->regs[MIPSInst_FT(ir)] == 0)
return 0;
DPFROMREG(rv.d, MIPSInst_FS(ir));
break;
#endif
case fabs_op:
handler.u = ieee754dp_abs;
goto dcopuop;
case fneg_op:
handler.u = ieee754dp_neg;
goto dcopuop;
case fmov_op:
/* an easy one */
DPFROMREG(rv.d, MIPSInst_FS(ir));
goto copcsr;
/* binary op on handler */
dcopbop:{
ieee754dp fs, ft;
DPFROMREG(fs, MIPSInst_FS(ir));
DPFROMREG(ft, MIPSInst_FT(ir));
rv.d = (*handler.b) (fs, ft);
goto copcsr;
}
dcopuop:{
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
rv.d = (*handler.u) (fs);
goto copcsr;
}
/* unary conv ops */
case fcvts_op:{
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
rv.s = ieee754sp_fdp(fs);
rfmt = s_fmt;
goto copcsr;
}
case fcvtd_op:
return SIGILL; /* not defined */
case fcvtw_op:{
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
rv.w = ieee754dp_tint(fs); /* wrong */
rfmt = w_fmt;
goto copcsr;
}
#if __mips >= 2 || defined(__mips64)
case fround_op:
case ftrunc_op:
case fceil_op:
case ffloor_op:{
unsigned int oldrm = ieee754_csr.rm;
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
rv.w = ieee754dp_tint(fs);
ieee754_csr.rm = oldrm;
rfmt = w_fmt;
goto copcsr;
}
#endif
#if defined(__mips64)
case fcvtl_op:{
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
rv.l = ieee754dp_tlong(fs);
rfmt = l_fmt;
goto copcsr;
}
case froundl_op:
case ftruncl_op:
case fceill_op:
case ffloorl_op:{
unsigned int oldrm = ieee754_csr.rm;
ieee754dp fs;
DPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
rv.l = ieee754dp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
goto copcsr;
}
#endif /* __mips >= 3 */
default:
if (MIPSInst_FUNC(ir) >= fcmp_op) {
unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
ieee754dp fs, ft;
DPFROMREG(fs, MIPSInst_FS(ir));
DPFROMREG(ft, MIPSInst_FT(ir));
rv.w = ieee754dp_cmp(fs, ft,
cmptab[cmpop & 0x7], cmpop & 0x8);
rfmt = -1;
if ((cmpop & 0x8)
&&
ieee754_cxtest
(IEEE754_INVALID_OPERATION))
rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S;
else
goto copcsr;
}
else {
return SIGILL;
}
break;
}
break;
}
case w_fmt:{
ieee754sp fs;
switch (MIPSInst_FUNC(ir)) {
case fcvts_op:
/* convert word to single precision real */
SPFROMREG(fs, MIPSInst_FS(ir));
rv.s = ieee754sp_fint(fs.bits);
rfmt = s_fmt;
goto copcsr;
case fcvtd_op:
/* convert word to double precision real */
SPFROMREG(fs, MIPSInst_FS(ir));
rv.d = ieee754dp_fint(fs.bits);
rfmt = d_fmt;
goto copcsr;
default:
return SIGILL;
}
break;
}
#if defined(__mips64)
case l_fmt:{
switch (MIPSInst_FUNC(ir)) {
case fcvts_op:
/* convert long to single precision real */
rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]);
rfmt = s_fmt;
goto copcsr;
case fcvtd_op:
/* convert long to double precision real */
rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]);
rfmt = d_fmt;
goto copcsr;
default:
return SIGILL;
}
break;
}
#endif
default:
return SIGILL;
}
/*
* Update the fpu CSR register for this operation.
* If an exception is required, generate a tidy SIGFPE exception,
* without updating the result register.
* Note: cause exception bits do not accumulate, they are rewritten
* for each op; only the flag/sticky bits accumulate.
*/
ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr;
if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
/*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */
return SIGFPE;
}
/*
* Now we can safely write the result back to the register file.
*/
switch (rfmt) {
case -1:{
#if __mips >= 4
cond = fpucondbit[MIPSInst_FD(ir) >> 2];
#else
cond = FPU_CSR_COND;
#endif
if (rv.w)
ctx->fcr31 |= cond;
else
ctx->fcr31 &= ~cond;
break;
}
case d_fmt:
DPTOREG(rv.d, MIPSInst_FD(ir));
break;
case s_fmt:
SPTOREG(rv.s, MIPSInst_FD(ir));
break;
case w_fmt:
SITOREG(rv.w, MIPSInst_FD(ir));
break;
#if defined(__mips64)
case l_fmt:
DITOREG(rv.l, MIPSInst_FD(ir));
break;
#endif
default:
return SIGILL;
}
return 0;
}
int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
int has_fpu, void *__user *fault_addr)
{
unsigned long oldepc, prevepc;
struct mm_decoded_insn dec_insn;
u16 instr[4];
u16 *instr_ptr;
int sig = 0;
oldepc = xcp->cp0_epc;
do {
prevepc = xcp->cp0_epc;
if (get_isa16_mode(prevepc) && cpu_has_mmips) {
/*
* Get next 2 microMIPS instructions and convert them
* into 32-bit instructions.
*/
if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) ||
(get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) ||
(get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) ||
(get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) {
MIPS_FPU_EMU_INC_STATS(errors);
return SIGBUS;
}
instr_ptr = instr;
/* Get first instruction. */
if (mm_insn_16bit(*instr_ptr)) {
/* Duplicate the half-word. */
dec_insn.insn = (*instr_ptr << 16) |
(*instr_ptr);
/* 16-bit instruction. */
dec_insn.pc_inc = 2;
instr_ptr += 1;
} else {
dec_insn.insn = (*instr_ptr << 16) |
*(instr_ptr+1);
/* 32-bit instruction. */
dec_insn.pc_inc = 4;
instr_ptr += 2;
}
/* Get second instruction. */
if (mm_insn_16bit(*instr_ptr)) {
/* Duplicate the half-word. */
dec_insn.next_insn = (*instr_ptr << 16) |
(*instr_ptr);
/* 16-bit instruction. */
dec_insn.next_pc_inc = 2;
} else {
dec_insn.next_insn = (*instr_ptr << 16) |
*(instr_ptr+1);
/* 32-bit instruction. */
dec_insn.next_pc_inc = 4;
}
dec_insn.micro_mips_mode = 1;
} else {
if ((get_user(dec_insn.insn,
(mips_instruction __user *) xcp->cp0_epc)) ||
(get_user(dec_insn.next_insn,
(mips_instruction __user *)(xcp->cp0_epc+4)))) {
MIPS_FPU_EMU_INC_STATS(errors);
return SIGBUS;
}
dec_insn.pc_inc = 4;
dec_insn.next_pc_inc = 4;
dec_insn.micro_mips_mode = 0;
}
if ((dec_insn.insn == 0) ||
((dec_insn.pc_inc == 2) &&
((dec_insn.insn & 0xffff) == MM_NOP16)))
xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */
else {
/*
* The 'ieee754_csr' is an alias of
* ctx->fcr31. No need to copy ctx->fcr31 to
* ieee754_csr. But ieee754_csr.rm is ieee
* library modes. (not mips rounding mode)
*/
/* convert to ieee library modes */
ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
/* revert to mips rounding mode */
ieee754_csr.rm = mips_rm[ieee754_csr.rm];
}
if (has_fpu)
break;
if (sig)
break;
cond_resched();
} while (xcp->cp0_epc > prevepc);
/* SIGILL indicates a non-fpu instruction */
if (sig == SIGILL && xcp->cp0_epc != oldepc)
/* but if epc has advanced, then ignore it */
sig = 0;
return sig;
}
#ifdef CONFIG_DEBUG_FS
static int fpuemu_stat_get(void *data, u64 *val)
{
int cpu;
unsigned long sum = 0;
for_each_online_cpu(cpu) {
struct mips_fpu_emulator_stats *ps;
local_t *pv;
ps = &per_cpu(fpuemustats, cpu);
pv = (void *)ps + (unsigned long)data;
sum += local_read(pv);
}
*val = sum;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n");
extern struct dentry *mips_debugfs_dir;
static int __init debugfs_fpuemu(void)
{
struct dentry *d, *dir;
if (!mips_debugfs_dir)
return -ENODEV;
dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir);
if (!dir)
return -ENOMEM;
#define FPU_STAT_CREATE(M) \
do { \
d = debugfs_create_file(#M , S_IRUGO, dir, \
(void *)offsetof(struct mips_fpu_emulator_stats, M), \
&fops_fpuemu_stat); \
if (!d) \
return -ENOMEM; \
} while (0)
FPU_STAT_CREATE(emulated);
FPU_STAT_CREATE(loads);
FPU_STAT_CREATE(stores);
FPU_STAT_CREATE(cp1ops);
FPU_STAT_CREATE(cp1xops);
FPU_STAT_CREATE(errors);
return 0;
}
__initcall(debugfs_fpuemu);
#endif
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