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linux_dsm_epyc7002/arch/mips/math-emu/cp1emu.c
Ralf Baechle 76fbfc318d MIPS: Sort out mm_isBranchInstr. 
mm_isBranchInstr() did reside in the math emu code even though it logically
is separate and also is used outside the math emu code.  In addition GCC 4.9.0
leaves the following unnnecessarily bloated function body for a non-microMIPS
configuration:

<mm_isBranchInstr>:
    105c:       afa50004        sw      a1,4(sp)
    1060:       afa60008        sw      a2,8(sp)
    1064:       afa7000c        sw      a3,12(sp)
    1068:       03e00008        jr      ra
    106c:       00001021        move    v0,zero

which stores arguments that are never going to be used on the stack frame.

Move mm_isBranchInstr() from cp1emu.c to branch.c, then split mm_isBranchInstr()
into a __mm_isBranchInstr() core and a mm_isBranchInstr() wrapper inline function
which only invokes __mm_isBranchInstr() on microMIPS configurations.

This shaves off 112 bytes off the kernel and improves code flow a bit.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-23 15:12:37 +02:00

1951 lines
48 KiB
C
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/*
* 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.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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/debugfs.h>
#include <linux/kconfig.h>
#include <linux/percpu-defs.h>
#include <linux/perf_event.h>
#include <asm/branch.h>
#include <asm/inst.h>
#include <asm/ptrace.h>
#include <asm/signal.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/fpu_emulator.h>
#include <asm/fpu.h>
#include "ieee754.h"
/* Function which emulates a floating point instruction. */
static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
mips_instruction);
static int fpux_emu(struct pt_regs *,
struct mips_fpu_struct *, mips_instruction, void *__user *);
/* 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)
/* 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,
};
/* 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
};
/* (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:
case mm_mfhc1_op:
case mm_mthc1_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 if (insn.mm_fp1_format.op == mm_ctc1_op)
op = ctc_op;
else if (insn.mm_fp1_format.op == mm_mfhc1_op)
op = mfhc_op;
else
op = mthc_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;
}
/*
* 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_FPREGS.
* 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 without 64-bit FPU support.
*/
static inline int cop1_64bit(struct pt_regs *xcp)
{
if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32))
return 1;
else if (config_enabled(CONFIG_32BIT) &&
!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
return 0;
return !test_thread_flag(TIF_32BIT_FPREGS);
}
#define SIFROMREG(si, x) \
do { \
if (cop1_64bit(xcp)) \
(si) = get_fpr32(&ctx->fpr[x], 0); \
else \
(si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
} while (0)
#define SITOREG(si, x) \
do { \
if (cop1_64bit(xcp)) { \
unsigned i; \
set_fpr32(&ctx->fpr[x], 0, si); \
for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
set_fpr32(&ctx->fpr[x], i, 0); \
} else { \
set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \
} \
} while (0)
#define SIFROMHREG(si, x) ((si) = get_fpr32(&ctx->fpr[x], 1))
#define SITOHREG(si, x) \
do { \
unsigned i; \
set_fpr32(&ctx->fpr[x], 1, si); \
for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \
set_fpr32(&ctx->fpr[x], i, 0); \
} while (0)
#define DIFROMREG(di, x) \
((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
#define DITOREG(di, x) \
do { \
unsigned fpr, i; \
fpr = (x) & ~(cop1_64bit(xcp) == 0); \
set_fpr64(&ctx->fpr[fpr], 0, di); \
for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \
set_fpr64(&ctx->fpr[fpr], i, 0); \
} while (0)
#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)
{
unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
unsigned int cond, cbit;
mips_instruction ir;
int likely, pc_inc;
u32 __user *wva;
u64 __user *dva;
u32 value;
u32 wval;
u64 dval;
int sig;
/* XXX NEC Vr54xx bug workaround */
if (delay_slot(xcp)) {
if (dec_insn.micro_mips_mode) {
if (!mm_isBranchInstr(xcp, dec_insn, &contpc))
clear_delay_slot(xcp);
} else {
if (!isBranchInstr(xcp, dec_insn, &contpc))
clear_delay_slot(xcp);
}
}
if (delay_slot(xcp)) {
/*
* 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:
dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, dva, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = dva;
return SIGBUS;
}
if (__get_user(dval, dva)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = dva;
return SIGSEGV;
}
DITOREG(dval, MIPSInst_RT(ir));
break;
case sdc1_op:
dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
MIPS_FPU_EMU_INC_STATS(stores);
DIFROMREG(dval, MIPSInst_RT(ir));
if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = dva;
return SIGBUS;
}
if (__put_user(dval, dva)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = dva;
return SIGSEGV;
}
break;
case lwc1_op:
wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
MIPS_FPU_EMU_INC_STATS(loads);
if (!access_ok(VERIFY_READ, wva, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = wva;
return SIGBUS;
}
if (__get_user(wval, wva)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = wva;
return SIGSEGV;
}
SITOREG(wval, MIPSInst_RT(ir));
break;
case swc1_op:
wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] +
MIPSInst_SIMM(ir));
MIPS_FPU_EMU_INC_STATS(stores);
SIFROMREG(wval, MIPSInst_RT(ir));
if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = wva;
return SIGBUS;
}
if (__put_user(wval, wva)) {
MIPS_FPU_EMU_INC_STATS(errors);
*fault_addr = wva;
return SIGSEGV;
}
break;
case cop1_op:
switch (MIPSInst_RS(ir)) {
case dmfc_op:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
/* copregister fs -> gpr[rt] */
if (MIPSInst_RT(ir) != 0) {
DIFROMREG(xcp->regs[MIPSInst_RT(ir)],
MIPSInst_RD(ir));
}
break;
case dmtc_op:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
/* copregister fs <- rt */
DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
break;
case mfhc_op:
if (!cpu_has_mips_r2)
goto sigill;
/* copregister rd -> gpr[rt] */
if (MIPSInst_RT(ir) != 0) {
SIFROMHREG(xcp->regs[MIPSInst_RT(ir)],
MIPSInst_RD(ir));
}
break;
case mthc_op:
if (!cpu_has_mips_r2)
goto sigill;
/* copregister rd <- gpr[rt] */
SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
break;
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] */
if (MIPSInst_RD(ir) == FPCREG_CSR) {
value = ctx->fcr31;
value = (value & ~FPU_CSR_RM) |
mips_rm[modeindex(value)];
pr_debug("%p gpr[%d]<-csr=%08x\n",
(void *) (xcp->cp0_epc),
MIPSInst_RT(ir), value);
}
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 */
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) {
pr_debug("%p gpr[%d]->csr=%08x\n",
(void *) (xcp->cp0_epc),
MIPSInst_RT(ir), value);
/*
* 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:
if (delay_slot(xcp))
return SIGILL;
if (cpu_has_mips_4_5_r)
cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
else
cbit = FPU_CSR_COND;
cond = ctx->fcr31 & cbit;
likely = 0;
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;
}
set_delay_slot(xcp);
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:
goto emul;
case swc1_op:
goto emul;
case ldc1_op:
case sdc1_op:
if (cpu_has_mips_2_3_4_5 ||
cpu_has_mips64)
goto emul;
return SIGILL;
goto emul;
case cop1_op:
goto emul;
case cop1x_op:
if (cpu_has_mips_4_5 || cpu_has_mips64)
/* its one of ours */
goto emul;
return SIGILL;
case spec_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
if (MIPSInst_FUNC(ir) == movc_op)
goto emul;
break;
}
/*
* Single step the non-cp1
* instruction in the dslot
*/
return mips_dsemul(xcp, ir, contpc);
} else if (likely) { /* branch not taken */
/*
* 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;
/* a real fpu computation instruction */
if ((sig = fpu_emu(xcp, ctx, ir)))
return sig;
}
break;
case cop1x_op:
if (!cpu_has_mips_4_5 && !cpu_has_mips64)
return SIGILL;
sig = fpux_emu(xcp, ctx, ir, fault_addr);
if (sig)
return sig;
break;
case spec_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
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;
default:
sigill:
return SIGILL;
}
/* we did it !! */
xcp->cp0_epc = contpc;
clear_delay_slot(xcp);
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 */
};
/*
* Additional MIPS4 instructions
*/
#define DEF3OP(name, p, f1, f2, f3) \
static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \
union ieee754##p s, union 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 union ieee754dp fpemu_dp_recip(union ieee754dp d)
{
return ieee754dp_div(ieee754dp_one(0), d);
}
static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d)
{
return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d));
}
static union ieee754sp fpemu_sp_recip(union ieee754sp s)
{
return ieee754sp_div(ieee754sp_one(0), s);
}
static union ieee754sp fpemu_sp_rsqrt(union 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 */
union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp);
union 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 */
union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp);
union 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 0x3:
if (MIPSInst_FUNC(ir) != pfetch_op)
return SIGILL;
/* ignore prefx operation */
break;
default:
return SIGILL;
}
return 0;
}
/*
* 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 int oldrm;
unsigned int cbit;
unsigned cond;
union {
union ieee754dp d;
union ieee754sp s;
int w;
s64 l;
} rv; /* resulting value */
u64 bits;
MIPS_FPU_EMU_INC_STATS(cp1ops);
switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) {
case s_fmt: { /* 0 */
union {
union ieee754sp(*b) (union ieee754sp, union ieee754sp);
union ieee754sp(*u) (union ieee754sp);
} handler;
union ieee754sp fs, ft;
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 */
case fsqrt_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
handler.u = ieee754sp_sqrt;
goto scopuop;
/*
* Note that on some MIPS IV implementations such as the
* R5000 and R8000 the FSQRT and FRECIP instructions do not
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
if (!cpu_has_mips_4_5_r2)
return SIGILL;
handler.u = fpemu_sp_rsqrt;
goto scopuop;
case frecip_op:
if (!cpu_has_mips_4_5_r2)
return SIGILL;
handler.u = fpemu_sp_recip;
goto scopuop;
case fmovc_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
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 (!cpu_has_mips_4_5_r)
return SIGILL;
if (xcp->regs[MIPSInst_FT(ir)] != 0)
return 0;
SPFROMREG(rv.s, MIPSInst_FS(ir));
break;
case fmovn_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
if (xcp->regs[MIPSInst_FT(ir)] == 0)
return 0;
SPFROMREG(rv.s, MIPSInst_FS(ir));
break;
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:
SPFROMREG(fs, MIPSInst_FS(ir));
SPFROMREG(ft, MIPSInst_FT(ir));
rv.s = (*handler.b) (fs, ft);
goto copcsr;
scopuop:
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:
SPFROMREG(fs, MIPSInst_FS(ir));
rv.d = ieee754dp_fsp(fs);
rfmt = d_fmt;
goto copcsr;
case fcvtw_op:
SPFROMREG(fs, MIPSInst_FS(ir));
rv.w = ieee754sp_tint(fs);
rfmt = w_fmt;
goto copcsr;
case fround_op:
case ftrunc_op:
case fceil_op:
case ffloor_op:
if (!cpu_has_mips_2_3_4_5 && !cpu_has_mips64)
return SIGILL;
oldrm = ieee754_csr.rm;
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;
case fcvtl_op:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
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:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
oldrm = ieee754_csr.rm;
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;
default:
if (MIPSInst_FUNC(ir) >= fcmp_op) {
unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
union 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 fs, ft;
union {
union ieee754dp(*b) (union ieee754dp, union ieee754dp);
union ieee754dp(*u) (union 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 */
case fsqrt_op:
if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
handler.u = ieee754dp_sqrt;
goto dcopuop;
/*
* Note that on some MIPS IV implementations such as the
* R5000 and R8000 the FSQRT and FRECIP instructions do not
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
if (!cpu_has_mips_4_5_r2)
return SIGILL;
handler.u = fpemu_dp_rsqrt;
goto dcopuop;
case frecip_op:
if (!cpu_has_mips_4_5_r2)
return SIGILL;
handler.u = fpemu_dp_recip;
goto dcopuop;
case fmovc_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
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 (!cpu_has_mips_4_5_r)
return SIGILL;
if (xcp->regs[MIPSInst_FT(ir)] != 0)
return 0;
DPFROMREG(rv.d, MIPSInst_FS(ir));
break;
case fmovn_op:
if (!cpu_has_mips_4_5_r)
return SIGILL;
if (xcp->regs[MIPSInst_FT(ir)] == 0)
return 0;
DPFROMREG(rv.d, MIPSInst_FS(ir));
break;
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:
DPFROMREG(fs, MIPSInst_FS(ir));
DPFROMREG(ft, MIPSInst_FT(ir));
rv.d = (*handler.b) (fs, ft);
goto copcsr;
dcopuop:
DPFROMREG(fs, MIPSInst_FS(ir));
rv.d = (*handler.u) (fs);
goto copcsr;
/*
* unary conv ops
*/
case fcvts_op:
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:
DPFROMREG(fs, MIPSInst_FS(ir));
rv.w = ieee754dp_tint(fs); /* wrong */
rfmt = w_fmt;
goto copcsr;
case fround_op:
case ftrunc_op:
case fceil_op:
case ffloor_op:
if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
oldrm = ieee754_csr.rm;
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;
case fcvtl_op:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
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:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
oldrm = ieee754_csr.rm;
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;
default:
if (MIPSInst_FUNC(ir) >= fcmp_op) {
unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op;
union 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:
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;
}
case l_fmt:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
DIFROMREG(bits, MIPSInst_FS(ir));
switch (MIPSInst_FUNC(ir)) {
case fcvts_op:
/* convert long to single precision real */
rv.s = ieee754sp_flong(bits);
rfmt = s_fmt;
goto copcsr;
case fcvtd_op:
/* convert long to double precision real */
rv.d = ieee754dp_flong(bits);
rfmt = d_fmt;
goto copcsr;
default:
return SIGILL;
}
break;
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 (cpu_has_mips_4_5_r)
cbit = fpucondbit[MIPSInst_RT(ir) >> 2];
else
cbit = FPU_CSR_COND;
if (rv.w)
ctx->fcr31 |= cbit;
else
ctx->fcr31 &= ~cbit;
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;
case l_fmt:
if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
return SIGILL;
DITOREG(rv.l, MIPSInst_FD(ir));
break;
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;
}
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