Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1322 insertions, 0 deletions

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
new file mode 100644
index 00000000000..20a552be02e
--- /dev/null
+++ b/arch/mips/math-emu/cp1emu.c
@@ -0,0 +1,1322 @@
+/*
+ * cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator
+ *
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ * http://www.algor.co.uk
+ *
+ * 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 <asm/inst.h>
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/cpu-features.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"
+#include "dsemul.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_soft_struct *,
+	mips_instruction);
+
+#if __mips >= 4 && __mips != 32
+static int fpux_emu(struct pt_regs *,
+	struct mips_fpu_soft_struct *, mips_instruction);
+#endif
+
+/* Further private data for which no space exists in mips_fpu_soft_struct */
+
+struct mips_fpu_emulator_private fpuemuprivate;
+
+/* Control registers */
+
+#define FPCREG_RID	0	/* $0  = revision id */
+#define FPCREG_CSR	31	/* $31 = csr */
+
+/* Convert Mips rounding mode (0..3) to IEEE library modes. */
+static const unsigned char ieee_rm[4] = {
+	IEEE754_RN, IEEE754_RZ, IEEE754_RU, IEEE754_RD
+};
+
+#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.  This does imply that, if a full 32
+ * FPRs are desired, there needs to be a flip-flop that can be written
+ * to one at that bit position.  In any case, O32 MIPS ABI uses
+ * only the even FPRs (Status.FR = 0).
+ */
+
+#define CP0_STATUS_FR_SUPPORT
+
+#ifdef CP0_STATUS_FR_SUPPORT
+#define FR_BIT ST0_FR
+#else
+#define FR_BIT 0
+#endif
+
+#define SIFROMREG(si,x)	((si) = \
+			(xcp->cp0_status & FR_BIT) || !(x & 1) ? \
+			(int)ctx->fpr[x] : \
+			(int)(ctx->fpr[x & ~1] >> 32 ))
+#define SITOREG(si,x)	(ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)] = \
+			(xcp->cp0_status & FR_BIT) || !(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 & ~((xcp->cp0_status & FR_BIT) == 0)])
+#define DITOREG(di,x)	(ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 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_soft_struct *ctx)
+{
+	mips_instruction ir;
+	vaddr_t emulpc, contpc;
+	unsigned int cond;
+
+	if (get_user(ir, (mips_instruction *) xcp->cp0_epc)) {
+		fpuemuprivate.stats.errors++;
+		return SIGBUS;
+	}
+
+	/* 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 = REG_TO_VA(xcp->cp0_epc + 4);	/* Snapshot emulation target */
+
+		if (__compute_return_epc(xcp)) {
+#ifdef CP1DBG
+			printk("failed to emulate branch at %p\n",
+				REG_TO_VA(xcp->cp0_epc));
+#endif
+			return SIGILL;
+		}
+		if (get_user(ir, (mips_instruction *) emulpc)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+		/* __compute_return_epc() will have updated cp0_epc */
+		contpc = REG_TO_VA xcp->cp0_epc;
+		/* In order not to confuse ptrace() et al, tweak context */
+		xcp->cp0_epc = VA_TO_REG emulpc - 4;
+	}
+	else {
+		emulpc = REG_TO_VA xcp->cp0_epc;
+		contpc = REG_TO_VA(xcp->cp0_epc + 4);
+	}
+
+      emul:
+	fpuemuprivate.stats.emulated++;
+	switch (MIPSInst_OPCODE(ir)) {
+#ifndef SINGLE_ONLY_FPU
+	case ldc1_op:{
+		u64 *va = REG_TO_VA(xcp->regs[MIPSInst_RS(ir)] +
+			MIPSInst_SIMM(ir));
+		u64 val;
+
+		fpuemuprivate.stats.loads++;
+		if (get_user(val, va)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+		DITOREG(val, MIPSInst_RT(ir));
+		break;
+	}
+
+	case sdc1_op:{
+		u64 *va = REG_TO_VA(xcp->regs[MIPSInst_RS(ir)] +
+			MIPSInst_SIMM(ir));
+		u64 val;
+
+		fpuemuprivate.stats.stores++;
+		DIFROMREG(val, MIPSInst_RT(ir));
+		if (put_user(val, va)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+		break;
+	}
+#endif
+
+	case lwc1_op:{
+		u32 *va = REG_TO_VA(xcp->regs[MIPSInst_RS(ir)] +
+			MIPSInst_SIMM(ir));
+		u32 val;
+
+		fpuemuprivate.stats.loads++;
+		if (get_user(val, va)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+#ifdef SINGLE_ONLY_FPU
+		if (MIPSInst_RT(ir) & 1) {
+			/* illegal register in single-float mode */
+			return SIGILL;
+		}
+#endif
+		SITOREG(val, MIPSInst_RT(ir));
+		break;
+	}
+
+	case swc1_op:{
+		u32 *va = REG_TO_VA(xcp->regs[MIPSInst_RS(ir)] +
+			MIPSInst_SIMM(ir));
+		u32 val;
+
+		fpuemuprivate.stats.stores++;
+#ifdef SINGLE_ONLY_FPU
+		if (MIPSInst_RT(ir) & 1) {
+			/* illegal register in single-float mode */
+			return SIGILL;
+		}
+#endif
+		SIFROMREG(val, MIPSInst_RT(ir));
+		if (put_user(val, va)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+		break;
+	}
+
+	case cop1_op:
+		switch (MIPSInst_RS(ir)) {
+
+#if __mips64 && !defined(SINGLE_ONLY_FPU)
+		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] */
+#ifdef SINGLE_ONLY_FPU
+			if (MIPSInst_RD(ir) & 1) {
+				/* illegal register in single-float mode */
+				return SIGILL;
+			}
+#endif
+			if (MIPSInst_RT(ir) != 0) {
+				SIFROMREG(xcp->regs[MIPSInst_RT(ir)],
+					MIPSInst_RD(ir));
+			}
+			break;
+
+		case mtc_op:
+			/* copregister rd <- rt */
+#ifdef SINGLE_ONLY_FPU
+			if (MIPSInst_RD(ir) & 1) {
+				/* illegal register in single-float mode */
+				return SIGILL;
+			}
+#endif
+			SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir));
+			break;
+
+		case cfc_op:{
+			/* cop control register rd -> gpr[rt] */
+			u32 value;
+
+			if (ir == CP1UNDEF) {
+				return do_dsemulret(xcp);
+			}
+			if (MIPSInst_RD(ir) == FPCREG_CSR) {
+				value = ctx->fcr31;
+#ifdef CSRTRACE
+				printk("%p gpr[%d]<-csr=%08x\n",
+					REG_TO_VA(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",
+					REG_TO_VA(xcp->cp0_epc),
+					MIPSInst_RT(ir), value);
+#endif
+				ctx->fcr31 = value;
+				/* copy new rounding mode and
+				   flush bit to ieee library state! */
+				ieee754_csr.nod = (ctx->fcr31 & 0x1000000) != 0;
+				ieee754_csr.rm = ieee_rm[value & 0x3];
+			}
+			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 = REG_TO_VA
+					(xcp->cp0_epc +
+					(MIPSInst_SIMM(ir) << 2));
+
+				if (get_user(ir, (mips_instruction *)
+						REG_TO_VA xcp->cp0_epc)) {
+					fpuemuprivate.stats.errors++;
+					return SIGBUS;
+				}
+
+				switch (MIPSInst_OPCODE(ir)) {
+				case lwc1_op:
+				case swc1_op:
+#if (__mips >= 2 || __mips64) && !defined(SINGLE_ONLY_FPU)
+				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, VA_TO_REG 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;
+
+		if ((sig = fpux_emu(xcp, ctx, ir)))
+			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 = VA_TO_REG(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_soft_struct *ctx,
+	mips_instruction ir)
+{
+	unsigned rcsr = 0;	/* resulting csr */
+
+	fpuemuprivate.stats.cp1xops++;
+
+	switch (MIPSInst_FMA_FFMT(ir)) {
+	case s_fmt:{		/* 0 */
+
+		ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp);
+		ieee754sp fd, fr, fs, ft;
+		u32 *va;
+		u32 val;
+
+		switch (MIPSInst_FUNC(ir)) {
+		case lwxc1_op:
+			va = REG_TO_VA(xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			fpuemuprivate.stats.loads++;
+			if (get_user(val, va)) {
+				fpuemuprivate.stats.errors++;
+				return SIGBUS;
+			}
+#ifdef SINGLE_ONLY_FPU
+			if (MIPSInst_FD(ir) & 1) {
+				/* illegal register in single-float
+				 * mode
+				 */
+				return SIGILL;
+			}
+#endif
+			SITOREG(val, MIPSInst_FD(ir));
+			break;
+
+		case swxc1_op:
+			va = REG_TO_VA(xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			fpuemuprivate.stats.stores++;
+#ifdef SINGLE_ONLY_FPU
+			if (MIPSInst_FS(ir) & 1) {
+				/* illegal register in single-float
+				 * mode
+				 */
+				return SIGILL;
+			}
+#endif
+
+			SIFROMREG(val, MIPSInst_FS(ir));
+			if (put_user(val, va)) {
+				fpuemuprivate.stats.errors++;
+				return SIGBUS;
+			}
+			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 (ieee754_csr.nod)
+				ctx->fcr31 |= 0x1000000;
+			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;
+	}
+
+#ifndef SINGLE_ONLY_FPU
+	case d_fmt:{		/* 1 */
+		ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp);
+		ieee754dp fd, fr, fs, ft;
+		u64 *va;
+		u64 val;
+
+		switch (MIPSInst_FUNC(ir)) {
+		case ldxc1_op:
+			va = REG_TO_VA(xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			fpuemuprivate.stats.loads++;
+			if (get_user(val, va)) {
+				fpuemuprivate.stats.errors++;
+				return SIGBUS;
+			}
+			DITOREG(val, MIPSInst_FD(ir));
+			break;
+
+		case sdxc1_op:
+			va = REG_TO_VA(xcp->regs[MIPSInst_FR(ir)] +
+				xcp->regs[MIPSInst_FT(ir)]);
+
+			fpuemuprivate.stats.stores++;
+			DIFROMREG(val, MIPSInst_FS(ir));
+			if (put_user(val, va)) {
+				fpuemuprivate.stats.errors++;
+				return SIGBUS;
+			}
+			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;
+	}
+#endif
+
+	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_soft_struct *ctx,
+	mips_instruction ir)
+{
+	int rfmt;		/* resulting format */
+	unsigned rcsr = 0;	/* resulting csr */
+	unsigned cond;
+	union {
+		ieee754dp d;
+		ieee754sp s;
+		int w;
+#if __mips64
+		s64 l;
+#endif
+	} rv;			/* resulting value */
+
+	fpuemuprivate.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 || __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:{
+#ifdef SINGLE_ONLY_FPU
+			return SIGILL;	/* not defined */
+#else
+			ieee754sp fs;
+
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.d = ieee754dp_fsp(fs);
+			rfmt = d_fmt;
+			goto copcsr;
+		}
+#endif
+		case fcvtw_op:{
+			ieee754sp fs;
+
+			SPFROMREG(fs, MIPSInst_FS(ir));
+			rv.w = ieee754sp_tint(fs);
+			rfmt = w_fmt;
+			goto copcsr;
+		}
+
+#if __mips >= 2 || __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[MIPSInst_FUNC(ir) & 0x3];
+			rv.w = ieee754sp_tint(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = w_fmt;
+			goto copcsr;
+		}
+#endif /* __mips >= 2 */
+
+#if __mips64 && !defined(SINGLE_ONLY_FPU)
+		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[MIPSInst_FUNC(ir) & 0x3];
+			rv.l = ieee754sp_tlong(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = l_fmt;
+			goto copcsr;
+		}
+#endif /* __mips64 && !fpu(single) */
+
+		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;
+	}
+
+#ifndef SINGLE_ONLY_FPU
+	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 || __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 || __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[MIPSInst_FUNC(ir) & 0x3];
+			rv.w = ieee754dp_tint(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = w_fmt;
+			goto copcsr;
+		}
+#endif
+
+#if __mips64 && !defined(SINGLE_ONLY_FPU)
+		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[MIPSInst_FUNC(ir) & 0x3];
+			rv.l = ieee754dp_tlong(fs);
+			ieee754_csr.rm = oldrm;
+			rfmt = l_fmt;
+			goto copcsr;
+		}
+#endif /* __mips >= 3 && !fpu(single) */
+
+		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;
+	}
+#endif /* ifndef SINGLE_ONLY_FPU */
+
+	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;
+#ifndef SINGLE_ONLY_FPU
+		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;
+#endif
+		default:
+			return SIGILL;
+		}
+		break;
+	}
+
+#if __mips64 && !defined(SINGLE_ONLY_FPU)
+	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;
+	}
+#ifndef SINGLE_ONLY_FPU
+	case d_fmt:
+		DPTOREG(rv.d, MIPSInst_FD(ir));
+		break;
+#endif
+	case s_fmt:
+		SPTOREG(rv.s, MIPSInst_FD(ir));
+		break;
+	case w_fmt:
+		SITOREG(rv.w, MIPSInst_FD(ir));
+		break;
+#if __mips64 && !defined(SINGLE_ONLY_FPU)
+	case l_fmt:
+		DITOREG(rv.l, MIPSInst_FD(ir));
+		break;
+#endif
+	default:
+		return SIGILL;
+	}
+
+	return 0;
+}
+
+int fpu_emulator_cop1Handler(int xcptno, struct pt_regs *xcp,
+	struct mips_fpu_soft_struct *ctx)
+{
+	gpreg_t oldepc, prevepc;
+	mips_instruction insn;
+	int sig = 0;
+
+	oldepc = xcp->cp0_epc;
+	do {
+		prevepc = xcp->cp0_epc;
+
+		if (get_user(insn, (mips_instruction *) xcp->cp0_epc)) {
+			fpuemuprivate.stats.errors++;
+			return SIGBUS;
+		}
+		if (insn == 0)
+			xcp->cp0_epc += 4;	/* skip nops */
+		else {
+			/* Update ieee754_csr. Only relevant if we have a
+			   h/w FPU */
+			ieee754_csr.nod = (ctx->fcr31 & 0x1000000) != 0;
+			ieee754_csr.rm = ieee_rm[ctx->fcr31 & 0x3];
+			ieee754_csr.cx = (ctx->fcr31 >> 12) & 0x1f;
+			sig = cop1Emulate(xcp, ctx);
+		}
+
+		if (cpu_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;
+}