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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/mips/math-emu/cp1emu.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/mips/math-emu/cp1emu.c')
-rw-r--r-- | arch/mips/math-emu/cp1emu.c | 1412 |
1 files changed, 1412 insertions, 0 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c new file mode 100644 index 00000000..a03bf00a --- /dev/null +++ b/arch/mips/math-emu/cp1emu.c @@ -0,0 +1,1412 @@ +/* + * 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/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) + +/* 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 + + +/* + * 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(mips_instruction * i) +{ + switch (MIPSInst_OPCODE(*i)) { + case spec_op: + switch (MIPSInst_FUNC(*i)) { + case jalr_op: + case jr_op: + return 1; + } + break; + + case bcond_op: + switch (MIPSInst_RT(*i)) { + case bltz_op: + case bgez_op: + case bltzl_op: + case bgezl_op: + case bltzal_op: + case bgezal_op: + case bltzall_op: + case bgezall_op: + return 1; + } + break; + + case j_op: + case jal_op: + case jalx_op: + case beq_op: + case bne_op: + case blez_op: + case bgtz_op: + case beql_op: + case bnel_op: + case blezl_op: + case bgtzl_op: + return 1; + + case cop0_op: + case cop1_op: + case cop2_op: + case cop1x_op: + if (MIPSInst_RS(*i) == bc_op) + 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. For 64-bit kernels with no FPU we use TIF_32BIT_REGS + * as a proxy for the FR bit so that a 64-bit FPU is emulated. In any + * case, for a 32-bit kernel which uses the O32 MIPS ABI, only the + * even FPRs are used (Status.FR = 0). + */ +static inline int cop1_64bit(struct pt_regs *xcp) +{ + if (cpu_has_fpu) + return xcp->cp0_status & ST0_FR; +#ifdef CONFIG_64BIT + 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, + void *__user *fault_addr) +{ + mips_instruction ir; + unsigned long emulpc, contpc; + unsigned int cond; + + if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGBUS; + } + if (__get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGSEGV; + } + + /* XXX NEC Vr54xx bug workaround */ + if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir)) + 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. + */ + emulpc = xcp->cp0_epc + 4; /* Snapshot emulation target */ + + if (__compute_return_epc(xcp) < 0) { +#ifdef CP1DBG + printk("failed to emulate branch at %p\n", + (void *) (xcp->cp0_epc)); +#endif + return SIGILL; + } + if (!access_ok(VERIFY_READ, emulpc, sizeof(mips_instruction))) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)emulpc; + return SIGBUS; + } + if (__get_user(ir, (mips_instruction __user *) emulpc)) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)emulpc; + return SIGSEGV; + } + /* __compute_return_epc() will have updated cp0_epc */ + contpc = xcp->cp0_epc; + /* In order not to confuse ptrace() et al, tweak context */ + xcp->cp0_epc = emulpc - 4; + } else { + emulpc = xcp->cp0_epc; + contpc = xcp->cp0_epc + 4; + } + + 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 += 4; + contpc = (xcp->cp0_epc + + (MIPSInst_SIMM(ir) << 2)); + + if (!access_ok(VERIFY_READ, xcp->cp0_epc, + sizeof(mips_instruction))) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGBUS; + } + if (__get_user(ir, + (mips_instruction __user *) xcp->cp0_epc)) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGSEGV; + } + + 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 += 4; + contpc += 4; + /* + * 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; + mips_instruction insn; + int sig = 0; + + oldepc = xcp->cp0_epc; + do { + prevepc = xcp->cp0_epc; + + if (!access_ok(VERIFY_READ, xcp->cp0_epc, sizeof(mips_instruction))) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGBUS; + } + if (__get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) { + MIPS_FPU_EMU_INC_STATS(errors); + *fault_addr = (mips_instruction __user *)xcp->cp0_epc; + return SIGSEGV; + } + if (insn == 0) + xcp->cp0_epc += 4; /* 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, 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 |