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Diffstat (limited to 'arch/mips/math-emu/cp1emu.c')
-rw-r--r--arch/mips/math-emu/cp1emu.c288
1 files changed, 200 insertions, 88 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index b30bf65c7d7d..d31c537ace1d 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -45,6 +45,7 @@
#include <asm/signal.h>
#include <asm/uaccess.h>
+#include <asm/cpu-info.h>
#include <asm/processor.h>
#include <asm/fpu_emulator.h>
#include <asm/fpu.h>
@@ -63,14 +64,14 @@ static int fpux_emu(struct pt_regs *,
/* Control registers */
#define FPCREG_RID 0 /* $0 = revision id */
+#define FPCREG_FCCR 25 /* $25 = fccr */
+#define FPCREG_FEXR 26 /* $26 = fexr */
+#define FPCREG_FENR 28 /* $28 = fenr */
#define FPCREG_CSR 31 /* $31 = csr */
-/* Determine rounding mode from the RM bits of the FCSR */
-#define modeindex(v) ((v) & FPU_CSR_RM)
-
/* convert condition code register number to csr bit */
const unsigned int fpucondbit[8] = {
- FPU_CSR_COND0,
+ FPU_CSR_COND,
FPU_CSR_COND1,
FPU_CSR_COND2,
FPU_CSR_COND3,
@@ -843,6 +844,127 @@ do { \
#define DPTOREG(dp, x) DITOREG((dp).bits, x)
/*
+ * Emulate a CFC1 instruction.
+ */
+static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+ mips_instruction ir)
+{
+ u32 fcr31 = ctx->fcr31;
+ u32 value = 0;
+
+ switch (MIPSInst_RD(ir)) {
+ case FPCREG_CSR:
+ value = fcr31;
+ pr_debug("%p gpr[%d]<-csr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ break;
+
+ case FPCREG_FENR:
+ if (!cpu_has_mips_r)
+ break;
+ value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
+ MIPS_FENR_FS;
+ value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM);
+ pr_debug("%p gpr[%d]<-enr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ break;
+
+ case FPCREG_FEXR:
+ if (!cpu_has_mips_r)
+ break;
+ value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+ pr_debug("%p gpr[%d]<-exr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ break;
+
+ case FPCREG_FCCR:
+ if (!cpu_has_mips_r)
+ break;
+ value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
+ MIPS_FCCR_COND0;
+ value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
+ (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0);
+ pr_debug("%p gpr[%d]<-ccr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ break;
+
+ case FPCREG_RID:
+ value = current_cpu_data.fpu_id;
+ break;
+
+ default:
+ break;
+ }
+
+ if (MIPSInst_RT(ir))
+ xcp->regs[MIPSInst_RT(ir)] = value;
+}
+
+/*
+ * Emulate a CTC1 instruction.
+ */
+static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
+ mips_instruction ir)
+{
+ u32 fcr31 = ctx->fcr31;
+ u32 value;
+ u32 mask;
+
+ if (MIPSInst_RT(ir) == 0)
+ value = 0;
+ else
+ value = xcp->regs[MIPSInst_RT(ir)];
+
+ switch (MIPSInst_RD(ir)) {
+ case FPCREG_CSR:
+ pr_debug("%p gpr[%d]->csr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+
+ /* Preserve read-only bits. */
+ mask = current_cpu_data.fpu_msk31;
+ fcr31 = (value & ~mask) | (fcr31 & mask);
+ break;
+
+ case FPCREG_FENR:
+ if (!cpu_has_mips_r)
+ break;
+ pr_debug("%p gpr[%d]->enr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM);
+ fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) &
+ FPU_CSR_FS;
+ fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM);
+ break;
+
+ case FPCREG_FEXR:
+ if (!cpu_has_mips_r)
+ break;
+ pr_debug("%p gpr[%d]->exr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+ fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S);
+ break;
+
+ case FPCREG_FCCR:
+ if (!cpu_has_mips_r)
+ break;
+ pr_debug("%p gpr[%d]->ccr=%08x\n",
+ (void *)xcp->cp0_epc, MIPSInst_RT(ir), value);
+ fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND);
+ fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) &
+ FPU_CSR_COND;
+ fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) &
+ FPU_CSR_CONDX;
+ break;
+
+ default:
+ break;
+ }
+
+ ctx->fcr31 = fcr31;
+}
+
+/*
* Emulate the single floating point instruction pointed at by EPC.
* Two instructions if the instruction is in a branch delay slot.
*/
@@ -856,7 +978,6 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
int likely, pc_inc;
u32 __user *wva;
u64 __user *dva;
- u32 value;
u32 wval;
u64 dval;
int sig;
@@ -1049,42 +1170,12 @@ emul:
case cfc_op:
/* cop control register rd -> gpr[rt] */
- if (MIPSInst_RD(ir) == FPCREG_CSR) {
- value = ctx->fcr31;
- value = (value & ~FPU_CSR_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;
+ cop1_cfc(xcp, ctx, ir);
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)) |
- modeindex(value);
- }
+ cop1_ctc(xcp, ctx, ir);
if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
return SIGFPE;
}
@@ -1103,17 +1194,18 @@ emul:
likely = 0;
switch (MIPSInst_RT(ir) & 3) {
case bcfl_op:
- likely = 1;
+ if (cpu_has_mips_2_3_4_5_r)
+ likely = 1;
+ /* Fall through */
case bcf_op:
cond = !cond;
break;
case bctl_op:
- likely = 1;
+ if (cpu_has_mips_2_3_4_5_r)
+ likely = 1;
+ /* Fall through */
case bct_op:
break;
- default:
- /* thats an illegal instruction */
- return SIGILL;
}
set_delay_slot(xcp);
@@ -1121,6 +1213,14 @@ emul:
/*
* Branch taken: emulate dslot instruction
*/
+ unsigned long bcpc;
+
+ /*
+ * Remember EPC at the branch to point back
+ * at so that any delay-slot instruction
+ * signal is not silently ignored.
+ */
+ bcpc = xcp->cp0_epc;
xcp->cp0_epc += dec_insn.pc_inc;
contpc = MIPSInst_SIMM(ir);
@@ -1146,63 +1246,77 @@ emul:
* Single step the non-CP1
* instruction in the dslot.
*/
- return mips_dsemul(xcp, ir, contpc);
+ sig = mips_dsemul(xcp, ir,
+ contpc);
+ if (sig)
+ xcp->cp0_epc = bcpc;
+ /*
+ * SIGILL forces out of
+ * the emulation loop.
+ */
+ return sig ? sig : SIGILL;
}
} 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)
+ if (cpu_has_mips_2_3_4_5_r)
goto emul;
- return SIGILL;
- goto emul;
+ goto bc_sigill;
case cop1_op:
goto emul;
case cop1x_op:
- if (cpu_has_mips_4_5 || cpu_has_mips64 || cpu_has_mips32r2)
+ if (cpu_has_mips_4_5_64_r2_r6)
/* its one of ours */
goto emul;
- return SIGILL;
+ goto bc_sigill;
case spec_op:
- if (!cpu_has_mips_4_5_r)
- return SIGILL;
+ switch (MIPSInst_FUNC(ir)) {
+ case movc_op:
+ if (cpu_has_mips_4_5_r)
+ goto emul;
- if (MIPSInst_FUNC(ir) == movc_op)
- goto emul;
+ goto bc_sigill;
+ }
break;
+
+ bc_sigill:
+ xcp->cp0_epc = bcpc;
+ return SIGILL;
}
/*
* Single step the non-cp1
* instruction in the dslot
*/
- return mips_dsemul(xcp, ir, contpc);
+ sig = mips_dsemul(xcp, ir, contpc);
+ if (sig)
+ xcp->cp0_epc = bcpc;
+ /* SIGILL forces out of the emulation loop. */
+ return sig ? sig : SIGILL;
} 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
- */
- }
+ /*
+ * 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:
@@ -1216,7 +1330,7 @@ emul:
break;
case cop1x_op:
- if (!cpu_has_mips_4_5 && !cpu_has_mips64 && !cpu_has_mips32r2)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
sig = fpux_emu(xcp, ctx, ir, fault_addr);
@@ -1549,7 +1663,7 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
/* unary ops */
case fsqrt_op:
- if (!cpu_has_mips_4_5_r)
+ if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
handler.u = ieee754sp_sqrt;
@@ -1561,14 +1675,14 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_sp_rsqrt;
goto scopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_sp_recip;
@@ -1670,19 +1784,19 @@ copcsr:
case ftrunc_op:
case fceil_op:
case ffloor_op:
- if (!cpu_has_mips_2_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
oldrm = ieee754_csr.rm;
SPFROMREG(fs, MIPSInst_FS(ir));
- ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
+ ieee754_csr.rm = 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)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
SPFROMREG(fs, MIPSInst_FS(ir));
@@ -1694,12 +1808,12 @@ copcsr:
case ftruncl_op:
case fceill_op:
case ffloorl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
oldrm = ieee754_csr.rm;
SPFROMREG(fs, MIPSInst_FS(ir));
- ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
+ ieee754_csr.rm = MIPSInst_FUNC(ir);
rv.l = ieee754sp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
@@ -1763,13 +1877,13 @@ copcsr:
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_dp_rsqrt;
goto dcopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_dp_recip;
@@ -1852,14 +1966,14 @@ dcopuop:
oldrm = ieee754_csr.rm;
DPFROMREG(fs, MIPSInst_FS(ir));
- ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
+ ieee754_csr.rm = 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)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DPFROMREG(fs, MIPSInst_FS(ir));
@@ -1871,12 +1985,12 @@ dcopuop:
case ftruncl_op:
case fceill_op:
case ffloorl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
oldrm = ieee754_csr.rm;
DPFROMREG(fs, MIPSInst_FS(ir));
- ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
+ ieee754_csr.rm = MIPSInst_FUNC(ir);
rv.l = ieee754dp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
@@ -1930,7 +2044,7 @@ dcopuop:
case l_fmt:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DIFROMREG(bits, MIPSInst_FS(ir));
@@ -1994,7 +2108,7 @@ dcopuop:
SITOREG(rv.w, MIPSInst_FD(ir));
break;
case l_fmt:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DITOREG(rv.l, MIPSInst_FD(ir));
@@ -2081,10 +2195,8 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
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)
+ * The 'ieee754_csr' is an alias of ctx->fcr31.
+ * No need to copy ctx->fcr31 to ieee754_csr.
*/
sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.