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-rw-r--r--arch/powerpc/math-emu/math_efp.c931
1 files changed, 931 insertions, 0 deletions
diff --git a/arch/powerpc/math-emu/math_efp.c b/arch/powerpc/math-emu/math_efp.c
new file mode 100644
index 000000000..34f62aafe
--- /dev/null
+++ b/arch/powerpc/math-emu/math_efp.c
@@ -0,0 +1,931 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * arch/powerpc/math-emu/math_efp.c
+ *
+ * Copyright (C) 2006-2008, 2010 Freescale Semiconductor, Inc.
+ *
+ * Author: Ebony Zhu, <ebony.zhu@freescale.com>
+ * Yu Liu, <yu.liu@freescale.com>
+ *
+ * Derived from arch/alpha/math-emu/math.c
+ * arch/powerpc/math-emu/math.c
+ *
+ * Description:
+ * This file is the exception handler to make E500 SPE instructions
+ * fully comply with IEEE-754 floating point standard.
+ */
+
+#include <linux/types.h>
+#include <linux/prctl.h>
+#include <linux/module.h>
+
+#include <linux/uaccess.h>
+#include <asm/reg.h>
+
+#define FP_EX_BOOKE_E500_SPE
+#include <asm/sfp-machine.h>
+
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+#include <math-emu/double.h>
+
+#define EFAPU 0x4
+
+#define VCT 0x4
+#define SPFP 0x6
+#define DPFP 0x7
+
+#define EFSADD 0x2c0
+#define EFSSUB 0x2c1
+#define EFSABS 0x2c4
+#define EFSNABS 0x2c5
+#define EFSNEG 0x2c6
+#define EFSMUL 0x2c8
+#define EFSDIV 0x2c9
+#define EFSCMPGT 0x2cc
+#define EFSCMPLT 0x2cd
+#define EFSCMPEQ 0x2ce
+#define EFSCFD 0x2cf
+#define EFSCFSI 0x2d1
+#define EFSCTUI 0x2d4
+#define EFSCTSI 0x2d5
+#define EFSCTUF 0x2d6
+#define EFSCTSF 0x2d7
+#define EFSCTUIZ 0x2d8
+#define EFSCTSIZ 0x2da
+
+#define EVFSADD 0x280
+#define EVFSSUB 0x281
+#define EVFSABS 0x284
+#define EVFSNABS 0x285
+#define EVFSNEG 0x286
+#define EVFSMUL 0x288
+#define EVFSDIV 0x289
+#define EVFSCMPGT 0x28c
+#define EVFSCMPLT 0x28d
+#define EVFSCMPEQ 0x28e
+#define EVFSCTUI 0x294
+#define EVFSCTSI 0x295
+#define EVFSCTUF 0x296
+#define EVFSCTSF 0x297
+#define EVFSCTUIZ 0x298
+#define EVFSCTSIZ 0x29a
+
+#define EFDADD 0x2e0
+#define EFDSUB 0x2e1
+#define EFDABS 0x2e4
+#define EFDNABS 0x2e5
+#define EFDNEG 0x2e6
+#define EFDMUL 0x2e8
+#define EFDDIV 0x2e9
+#define EFDCTUIDZ 0x2ea
+#define EFDCTSIDZ 0x2eb
+#define EFDCMPGT 0x2ec
+#define EFDCMPLT 0x2ed
+#define EFDCMPEQ 0x2ee
+#define EFDCFS 0x2ef
+#define EFDCTUI 0x2f4
+#define EFDCTSI 0x2f5
+#define EFDCTUF 0x2f6
+#define EFDCTSF 0x2f7
+#define EFDCTUIZ 0x2f8
+#define EFDCTSIZ 0x2fa
+
+#define AB 2
+#define XA 3
+#define XB 4
+#define XCR 5
+#define NOTYPE 0
+
+#define SIGN_BIT_S (1UL << 31)
+#define SIGN_BIT_D (1ULL << 63)
+#define FP_EX_MASK (FP_EX_INEXACT | FP_EX_INVALID | FP_EX_DIVZERO | \
+ FP_EX_UNDERFLOW | FP_EX_OVERFLOW)
+
+static int have_e500_cpu_a005_erratum;
+
+union dw_union {
+ u64 dp[1];
+ u32 wp[2];
+};
+
+static unsigned long insn_type(unsigned long speinsn)
+{
+ unsigned long ret = NOTYPE;
+
+ switch (speinsn & 0x7ff) {
+ case EFSABS: ret = XA; break;
+ case EFSADD: ret = AB; break;
+ case EFSCFD: ret = XB; break;
+ case EFSCMPEQ: ret = XCR; break;
+ case EFSCMPGT: ret = XCR; break;
+ case EFSCMPLT: ret = XCR; break;
+ case EFSCTSF: ret = XB; break;
+ case EFSCTSI: ret = XB; break;
+ case EFSCTSIZ: ret = XB; break;
+ case EFSCTUF: ret = XB; break;
+ case EFSCTUI: ret = XB; break;
+ case EFSCTUIZ: ret = XB; break;
+ case EFSDIV: ret = AB; break;
+ case EFSMUL: ret = AB; break;
+ case EFSNABS: ret = XA; break;
+ case EFSNEG: ret = XA; break;
+ case EFSSUB: ret = AB; break;
+ case EFSCFSI: ret = XB; break;
+
+ case EVFSABS: ret = XA; break;
+ case EVFSADD: ret = AB; break;
+ case EVFSCMPEQ: ret = XCR; break;
+ case EVFSCMPGT: ret = XCR; break;
+ case EVFSCMPLT: ret = XCR; break;
+ case EVFSCTSF: ret = XB; break;
+ case EVFSCTSI: ret = XB; break;
+ case EVFSCTSIZ: ret = XB; break;
+ case EVFSCTUF: ret = XB; break;
+ case EVFSCTUI: ret = XB; break;
+ case EVFSCTUIZ: ret = XB; break;
+ case EVFSDIV: ret = AB; break;
+ case EVFSMUL: ret = AB; break;
+ case EVFSNABS: ret = XA; break;
+ case EVFSNEG: ret = XA; break;
+ case EVFSSUB: ret = AB; break;
+
+ case EFDABS: ret = XA; break;
+ case EFDADD: ret = AB; break;
+ case EFDCFS: ret = XB; break;
+ case EFDCMPEQ: ret = XCR; break;
+ case EFDCMPGT: ret = XCR; break;
+ case EFDCMPLT: ret = XCR; break;
+ case EFDCTSF: ret = XB; break;
+ case EFDCTSI: ret = XB; break;
+ case EFDCTSIDZ: ret = XB; break;
+ case EFDCTSIZ: ret = XB; break;
+ case EFDCTUF: ret = XB; break;
+ case EFDCTUI: ret = XB; break;
+ case EFDCTUIDZ: ret = XB; break;
+ case EFDCTUIZ: ret = XB; break;
+ case EFDDIV: ret = AB; break;
+ case EFDMUL: ret = AB; break;
+ case EFDNABS: ret = XA; break;
+ case EFDNEG: ret = XA; break;
+ case EFDSUB: ret = AB; break;
+ }
+
+ return ret;
+}
+
+int do_spe_mathemu(struct pt_regs *regs)
+{
+ FP_DECL_EX;
+ int IR, cmp;
+
+ unsigned long type, func, fc, fa, fb, src, speinsn;
+ union dw_union vc, va, vb;
+
+ if (get_user(speinsn, (unsigned int __user *) regs->nip))
+ return -EFAULT;
+ if ((speinsn >> 26) != EFAPU)
+ return -EINVAL; /* not an spe instruction */
+
+ type = insn_type(speinsn);
+ if (type == NOTYPE)
+ goto illegal;
+
+ func = speinsn & 0x7ff;
+ fc = (speinsn >> 21) & 0x1f;
+ fa = (speinsn >> 16) & 0x1f;
+ fb = (speinsn >> 11) & 0x1f;
+ src = (speinsn >> 5) & 0x7;
+
+ vc.wp[0] = current->thread.evr[fc];
+ vc.wp[1] = regs->gpr[fc];
+ va.wp[0] = current->thread.evr[fa];
+ va.wp[1] = regs->gpr[fa];
+ vb.wp[0] = current->thread.evr[fb];
+ vb.wp[1] = regs->gpr[fb];
+
+ __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
+
+ pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
+ pr_debug("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
+ pr_debug("va: %08x %08x\n", va.wp[0], va.wp[1]);
+ pr_debug("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
+
+ switch (src) {
+ case SPFP: {
+ FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
+
+ switch (type) {
+ case AB:
+ case XCR:
+ FP_UNPACK_SP(SA, va.wp + 1);
+ fallthrough;
+ case XB:
+ FP_UNPACK_SP(SB, vb.wp + 1);
+ break;
+ case XA:
+ FP_UNPACK_SP(SA, va.wp + 1);
+ break;
+ }
+
+ pr_debug("SA: %d %08x %d (%d)\n", SA_s, SA_f, SA_e, SA_c);
+ pr_debug("SB: %d %08x %d (%d)\n", SB_s, SB_f, SB_e, SB_c);
+
+ switch (func) {
+ case EFSABS:
+ vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
+ goto update_regs;
+
+ case EFSNABS:
+ vc.wp[1] = va.wp[1] | SIGN_BIT_S;
+ goto update_regs;
+
+ case EFSNEG:
+ vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
+ goto update_regs;
+
+ case EFSADD:
+ FP_ADD_S(SR, SA, SB);
+ goto pack_s;
+
+ case EFSSUB:
+ FP_SUB_S(SR, SA, SB);
+ goto pack_s;
+
+ case EFSMUL:
+ FP_MUL_S(SR, SA, SB);
+ goto pack_s;
+
+ case EFSDIV:
+ FP_DIV_S(SR, SA, SB);
+ goto pack_s;
+
+ case EFSCMPEQ:
+ cmp = 0;
+ goto cmp_s;
+
+ case EFSCMPGT:
+ cmp = 1;
+ goto cmp_s;
+
+ case EFSCMPLT:
+ cmp = -1;
+ goto cmp_s;
+
+ case EFSCTSF:
+ case EFSCTUF:
+ if (SB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ SB_e += (func == EFSCTSF ? 31 : 32);
+ FP_TO_INT_ROUND_S(vc.wp[1], SB, 32,
+ (func == EFSCTSF) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EFSCFD: {
+ FP_DECL_D(DB);
+ FP_CLEAR_EXCEPTIONS;
+ FP_UNPACK_DP(DB, vb.dp);
+
+ pr_debug("DB: %d %08x %08x %d (%d)\n",
+ DB_s, DB_f1, DB_f0, DB_e, DB_c);
+
+ FP_CONV(S, D, 1, 2, SR, DB);
+ goto pack_s;
+ }
+
+ case EFSCTSI:
+ case EFSCTUI:
+ if (SB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_ROUND_S(vc.wp[1], SB, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EFSCTSIZ:
+ case EFSCTUIZ:
+ if (SB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_S(vc.wp[1], SB, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ default:
+ goto illegal;
+ }
+ break;
+
+pack_s:
+ pr_debug("SR: %d %08x %d (%d)\n", SR_s, SR_f, SR_e, SR_c);
+
+ FP_PACK_SP(vc.wp + 1, SR);
+ goto update_regs;
+
+cmp_s:
+ FP_CMP_S(IR, SA, SB, 3);
+ if (IR == 3 && (FP_ISSIGNAN_S(SA) || FP_ISSIGNAN_S(SB)))
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ if (IR == cmp) {
+ IR = 0x4;
+ } else {
+ IR = 0;
+ }
+ goto update_ccr;
+ }
+
+ case DPFP: {
+ FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
+
+ switch (type) {
+ case AB:
+ case XCR:
+ FP_UNPACK_DP(DA, va.dp);
+ fallthrough;
+ case XB:
+ FP_UNPACK_DP(DB, vb.dp);
+ break;
+ case XA:
+ FP_UNPACK_DP(DA, va.dp);
+ break;
+ }
+
+ pr_debug("DA: %d %08x %08x %d (%d)\n",
+ DA_s, DA_f1, DA_f0, DA_e, DA_c);
+ pr_debug("DB: %d %08x %08x %d (%d)\n",
+ DB_s, DB_f1, DB_f0, DB_e, DB_c);
+
+ switch (func) {
+ case EFDABS:
+ vc.dp[0] = va.dp[0] & ~SIGN_BIT_D;
+ goto update_regs;
+
+ case EFDNABS:
+ vc.dp[0] = va.dp[0] | SIGN_BIT_D;
+ goto update_regs;
+
+ case EFDNEG:
+ vc.dp[0] = va.dp[0] ^ SIGN_BIT_D;
+ goto update_regs;
+
+ case EFDADD:
+ FP_ADD_D(DR, DA, DB);
+ goto pack_d;
+
+ case EFDSUB:
+ FP_SUB_D(DR, DA, DB);
+ goto pack_d;
+
+ case EFDMUL:
+ FP_MUL_D(DR, DA, DB);
+ goto pack_d;
+
+ case EFDDIV:
+ FP_DIV_D(DR, DA, DB);
+ goto pack_d;
+
+ case EFDCMPEQ:
+ cmp = 0;
+ goto cmp_d;
+
+ case EFDCMPGT:
+ cmp = 1;
+ goto cmp_d;
+
+ case EFDCMPLT:
+ cmp = -1;
+ goto cmp_d;
+
+ case EFDCTSF:
+ case EFDCTUF:
+ if (DB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ DB_e += (func == EFDCTSF ? 31 : 32);
+ FP_TO_INT_ROUND_D(vc.wp[1], DB, 32,
+ (func == EFDCTSF) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EFDCFS: {
+ FP_DECL_S(SB);
+ FP_CLEAR_EXCEPTIONS;
+ FP_UNPACK_SP(SB, vb.wp + 1);
+
+ pr_debug("SB: %d %08x %d (%d)\n",
+ SB_s, SB_f, SB_e, SB_c);
+
+ FP_CONV(D, S, 2, 1, DR, SB);
+ goto pack_d;
+ }
+
+ case EFDCTUIDZ:
+ case EFDCTSIDZ:
+ if (DB_c == FP_CLS_NAN) {
+ vc.dp[0] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_D(vc.dp[0], DB, 64,
+ ((func & 0x1) == 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EFDCTUI:
+ case EFDCTSI:
+ if (DB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_ROUND_D(vc.wp[1], DB, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EFDCTUIZ:
+ case EFDCTSIZ:
+ if (DB_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_D(vc.wp[1], DB, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ default:
+ goto illegal;
+ }
+ break;
+
+pack_d:
+ pr_debug("DR: %d %08x %08x %d (%d)\n",
+ DR_s, DR_f1, DR_f0, DR_e, DR_c);
+
+ FP_PACK_DP(vc.dp, DR);
+ goto update_regs;
+
+cmp_d:
+ FP_CMP_D(IR, DA, DB, 3);
+ if (IR == 3 && (FP_ISSIGNAN_D(DA) || FP_ISSIGNAN_D(DB)))
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ if (IR == cmp) {
+ IR = 0x4;
+ } else {
+ IR = 0;
+ }
+ goto update_ccr;
+
+ }
+
+ case VCT: {
+ FP_DECL_S(SA0); FP_DECL_S(SB0); FP_DECL_S(SR0);
+ FP_DECL_S(SA1); FP_DECL_S(SB1); FP_DECL_S(SR1);
+ int IR0, IR1;
+
+ switch (type) {
+ case AB:
+ case XCR:
+ FP_UNPACK_SP(SA0, va.wp);
+ FP_UNPACK_SP(SA1, va.wp + 1);
+ fallthrough;
+ case XB:
+ FP_UNPACK_SP(SB0, vb.wp);
+ FP_UNPACK_SP(SB1, vb.wp + 1);
+ break;
+ case XA:
+ FP_UNPACK_SP(SA0, va.wp);
+ FP_UNPACK_SP(SA1, va.wp + 1);
+ break;
+ }
+
+ pr_debug("SA0: %d %08x %d (%d)\n",
+ SA0_s, SA0_f, SA0_e, SA0_c);
+ pr_debug("SA1: %d %08x %d (%d)\n",
+ SA1_s, SA1_f, SA1_e, SA1_c);
+ pr_debug("SB0: %d %08x %d (%d)\n",
+ SB0_s, SB0_f, SB0_e, SB0_c);
+ pr_debug("SB1: %d %08x %d (%d)\n",
+ SB1_s, SB1_f, SB1_e, SB1_c);
+
+ switch (func) {
+ case EVFSABS:
+ vc.wp[0] = va.wp[0] & ~SIGN_BIT_S;
+ vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
+ goto update_regs;
+
+ case EVFSNABS:
+ vc.wp[0] = va.wp[0] | SIGN_BIT_S;
+ vc.wp[1] = va.wp[1] | SIGN_BIT_S;
+ goto update_regs;
+
+ case EVFSNEG:
+ vc.wp[0] = va.wp[0] ^ SIGN_BIT_S;
+ vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
+ goto update_regs;
+
+ case EVFSADD:
+ FP_ADD_S(SR0, SA0, SB0);
+ FP_ADD_S(SR1, SA1, SB1);
+ goto pack_vs;
+
+ case EVFSSUB:
+ FP_SUB_S(SR0, SA0, SB0);
+ FP_SUB_S(SR1, SA1, SB1);
+ goto pack_vs;
+
+ case EVFSMUL:
+ FP_MUL_S(SR0, SA0, SB0);
+ FP_MUL_S(SR1, SA1, SB1);
+ goto pack_vs;
+
+ case EVFSDIV:
+ FP_DIV_S(SR0, SA0, SB0);
+ FP_DIV_S(SR1, SA1, SB1);
+ goto pack_vs;
+
+ case EVFSCMPEQ:
+ cmp = 0;
+ goto cmp_vs;
+
+ case EVFSCMPGT:
+ cmp = 1;
+ goto cmp_vs;
+
+ case EVFSCMPLT:
+ cmp = -1;
+ goto cmp_vs;
+
+ case EVFSCTUF:
+ case EVFSCTSF:
+ if (SB0_c == FP_CLS_NAN) {
+ vc.wp[0] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ SB0_e += (func == EVFSCTSF ? 31 : 32);
+ FP_TO_INT_ROUND_S(vc.wp[0], SB0, 32,
+ (func == EVFSCTSF) ? 1 : 0);
+ }
+ if (SB1_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ SB1_e += (func == EVFSCTSF ? 31 : 32);
+ FP_TO_INT_ROUND_S(vc.wp[1], SB1, 32,
+ (func == EVFSCTSF) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EVFSCTUI:
+ case EVFSCTSI:
+ if (SB0_c == FP_CLS_NAN) {
+ vc.wp[0] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_ROUND_S(vc.wp[0], SB0, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ if (SB1_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_ROUND_S(vc.wp[1], SB1, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ case EVFSCTUIZ:
+ case EVFSCTSIZ:
+ if (SB0_c == FP_CLS_NAN) {
+ vc.wp[0] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_S(vc.wp[0], SB0, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ if (SB1_c == FP_CLS_NAN) {
+ vc.wp[1] = 0;
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ } else {
+ FP_TO_INT_S(vc.wp[1], SB1, 32,
+ ((func & 0x3) != 0) ? 1 : 0);
+ }
+ goto update_regs;
+
+ default:
+ goto illegal;
+ }
+ break;
+
+pack_vs:
+ pr_debug("SR0: %d %08x %d (%d)\n",
+ SR0_s, SR0_f, SR0_e, SR0_c);
+ pr_debug("SR1: %d %08x %d (%d)\n",
+ SR1_s, SR1_f, SR1_e, SR1_c);
+
+ FP_PACK_SP(vc.wp, SR0);
+ FP_PACK_SP(vc.wp + 1, SR1);
+ goto update_regs;
+
+cmp_vs:
+ {
+ int ch, cl;
+
+ FP_CMP_S(IR0, SA0, SB0, 3);
+ FP_CMP_S(IR1, SA1, SB1, 3);
+ if (IR0 == 3 && (FP_ISSIGNAN_S(SA0) || FP_ISSIGNAN_S(SB0)))
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ if (IR1 == 3 && (FP_ISSIGNAN_S(SA1) || FP_ISSIGNAN_S(SB1)))
+ FP_SET_EXCEPTION(FP_EX_INVALID);
+ ch = (IR0 == cmp) ? 1 : 0;
+ cl = (IR1 == cmp) ? 1 : 0;
+ IR = (ch << 3) | (cl << 2) | ((ch | cl) << 1) |
+ ((ch & cl) << 0);
+ goto update_ccr;
+ }
+ }
+ default:
+ return -EINVAL;
+ }
+
+update_ccr:
+ regs->ccr &= ~(15 << ((7 - ((speinsn >> 23) & 0x7)) << 2));
+ regs->ccr |= (IR << ((7 - ((speinsn >> 23) & 0x7)) << 2));
+
+update_regs:
+ /*
+ * If the "invalid" exception sticky bit was set by the
+ * processor for non-finite input, but was not set before the
+ * instruction being emulated, clear it. Likewise for the
+ * "underflow" bit, which may have been set by the processor
+ * for exact underflow, not just inexact underflow when the
+ * flag should be set for IEEE 754 semantics. Other sticky
+ * exceptions will only be set by the processor when they are
+ * correct according to IEEE 754 semantics, and we must not
+ * clear sticky bits that were already set before the emulated
+ * instruction as they represent the user-visible sticky
+ * exception status. "inexact" traps to kernel are not
+ * required for IEEE semantics and are not enabled by default,
+ * so the "inexact" sticky bit may have been set by a previous
+ * instruction without the kernel being aware of it.
+ */
+ __FPU_FPSCR
+ &= ~(FP_EX_INVALID | FP_EX_UNDERFLOW) | current->thread.spefscr_last;
+ __FPU_FPSCR |= (FP_CUR_EXCEPTIONS & FP_EX_MASK);
+ mtspr(SPRN_SPEFSCR, __FPU_FPSCR);
+ current->thread.spefscr_last = __FPU_FPSCR;
+
+ current->thread.evr[fc] = vc.wp[0];
+ regs->gpr[fc] = vc.wp[1];
+
+ pr_debug("ccr = %08lx\n", regs->ccr);
+ pr_debug("cur exceptions = %08x spefscr = %08lx\n",
+ FP_CUR_EXCEPTIONS, __FPU_FPSCR);
+ pr_debug("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
+ pr_debug("va: %08x %08x\n", va.wp[0], va.wp[1]);
+ pr_debug("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
+
+ if (current->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
+ if ((FP_CUR_EXCEPTIONS & FP_EX_DIVZERO)
+ && (current->thread.fpexc_mode & PR_FP_EXC_DIV))
+ return 1;
+ if ((FP_CUR_EXCEPTIONS & FP_EX_OVERFLOW)
+ && (current->thread.fpexc_mode & PR_FP_EXC_OVF))
+ return 1;
+ if ((FP_CUR_EXCEPTIONS & FP_EX_UNDERFLOW)
+ && (current->thread.fpexc_mode & PR_FP_EXC_UND))
+ return 1;
+ if ((FP_CUR_EXCEPTIONS & FP_EX_INEXACT)
+ && (current->thread.fpexc_mode & PR_FP_EXC_RES))
+ return 1;
+ if ((FP_CUR_EXCEPTIONS & FP_EX_INVALID)
+ && (current->thread.fpexc_mode & PR_FP_EXC_INV))
+ return 1;
+ }
+ return 0;
+
+illegal:
+ if (have_e500_cpu_a005_erratum) {
+ /* according to e500 cpu a005 erratum, reissue efp inst */
+ regs_add_return_ip(regs, -4);
+ pr_debug("re-issue efp inst: %08lx\n", speinsn);
+ return 0;
+ }
+
+ printk(KERN_ERR "\nOoops! IEEE-754 compliance handler encountered un-supported instruction.\ninst code: %08lx\n", speinsn);
+ return -ENOSYS;
+}
+
+int speround_handler(struct pt_regs *regs)
+{
+ union dw_union fgpr;
+ int s_lo, s_hi;
+ int lo_inexact, hi_inexact;
+ int fp_result;
+ unsigned long speinsn, type, fb, fc, fptype, func;
+
+ if (get_user(speinsn, (unsigned int __user *) regs->nip))
+ return -EFAULT;
+ if ((speinsn >> 26) != 4)
+ return -EINVAL; /* not an spe instruction */
+
+ func = speinsn & 0x7ff;
+ type = insn_type(func);
+ if (type == XCR) return -ENOSYS;
+
+ __FPU_FPSCR = mfspr(SPRN_SPEFSCR);
+ pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
+
+ fptype = (speinsn >> 5) & 0x7;
+
+ /* No need to round if the result is exact */
+ lo_inexact = __FPU_FPSCR & (SPEFSCR_FG | SPEFSCR_FX);
+ hi_inexact = __FPU_FPSCR & (SPEFSCR_FGH | SPEFSCR_FXH);
+ if (!(lo_inexact || (hi_inexact && fptype == VCT)))
+ return 0;
+
+ fc = (speinsn >> 21) & 0x1f;
+ s_lo = regs->gpr[fc] & SIGN_BIT_S;
+ s_hi = current->thread.evr[fc] & SIGN_BIT_S;
+ fgpr.wp[0] = current->thread.evr[fc];
+ fgpr.wp[1] = regs->gpr[fc];
+
+ fb = (speinsn >> 11) & 0x1f;
+ switch (func) {
+ case EFSCTUIZ:
+ case EFSCTSIZ:
+ case EVFSCTUIZ:
+ case EVFSCTSIZ:
+ case EFDCTUIDZ:
+ case EFDCTSIDZ:
+ case EFDCTUIZ:
+ case EFDCTSIZ:
+ /*
+ * These instructions always round to zero,
+ * independent of the rounding mode.
+ */
+ return 0;
+
+ case EFSCTUI:
+ case EFSCTUF:
+ case EVFSCTUI:
+ case EVFSCTUF:
+ case EFDCTUI:
+ case EFDCTUF:
+ fp_result = 0;
+ s_lo = 0;
+ s_hi = 0;
+ break;
+
+ case EFSCTSI:
+ case EFSCTSF:
+ fp_result = 0;
+ /* Recover the sign of a zero result if possible. */
+ if (fgpr.wp[1] == 0)
+ s_lo = regs->gpr[fb] & SIGN_BIT_S;
+ break;
+
+ case EVFSCTSI:
+ case EVFSCTSF:
+ fp_result = 0;
+ /* Recover the sign of a zero result if possible. */
+ if (fgpr.wp[1] == 0)
+ s_lo = regs->gpr[fb] & SIGN_BIT_S;
+ if (fgpr.wp[0] == 0)
+ s_hi = current->thread.evr[fb] & SIGN_BIT_S;
+ break;
+
+ case EFDCTSI:
+ case EFDCTSF:
+ fp_result = 0;
+ s_hi = s_lo;
+ /* Recover the sign of a zero result if possible. */
+ if (fgpr.wp[1] == 0)
+ s_hi = current->thread.evr[fb] & SIGN_BIT_S;
+ break;
+
+ default:
+ fp_result = 1;
+ break;
+ }
+
+ pr_debug("round fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
+
+ switch (fptype) {
+ /* Since SPE instructions on E500 core can handle round to nearest
+ * and round toward zero with IEEE-754 complied, we just need
+ * to handle round toward +Inf and round toward -Inf by software.
+ */
+ case SPFP:
+ if ((FP_ROUNDMODE) == FP_RND_PINF) {
+ if (!s_lo) fgpr.wp[1]++; /* Z > 0, choose Z1 */
+ } else { /* round to -Inf */
+ if (s_lo) {
+ if (fp_result)
+ fgpr.wp[1]++; /* Z < 0, choose Z2 */
+ else
+ fgpr.wp[1]--; /* Z < 0, choose Z2 */
+ }
+ }
+ break;
+
+ case DPFP:
+ if (FP_ROUNDMODE == FP_RND_PINF) {
+ if (!s_hi) {
+ if (fp_result)
+ fgpr.dp[0]++; /* Z > 0, choose Z1 */
+ else
+ fgpr.wp[1]++; /* Z > 0, choose Z1 */
+ }
+ } else { /* round to -Inf */
+ if (s_hi) {
+ if (fp_result)
+ fgpr.dp[0]++; /* Z < 0, choose Z2 */
+ else
+ fgpr.wp[1]--; /* Z < 0, choose Z2 */
+ }
+ }
+ break;
+
+ case VCT:
+ if (FP_ROUNDMODE == FP_RND_PINF) {
+ if (lo_inexact && !s_lo)
+ fgpr.wp[1]++; /* Z_low > 0, choose Z1 */
+ if (hi_inexact && !s_hi)
+ fgpr.wp[0]++; /* Z_high word > 0, choose Z1 */
+ } else { /* round to -Inf */
+ if (lo_inexact && s_lo) {
+ if (fp_result)
+ fgpr.wp[1]++; /* Z_low < 0, choose Z2 */
+ else
+ fgpr.wp[1]--; /* Z_low < 0, choose Z2 */
+ }
+ if (hi_inexact && s_hi) {
+ if (fp_result)
+ fgpr.wp[0]++; /* Z_high < 0, choose Z2 */
+ else
+ fgpr.wp[0]--; /* Z_high < 0, choose Z2 */
+ }
+ }
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ current->thread.evr[fc] = fgpr.wp[0];
+ regs->gpr[fc] = fgpr.wp[1];
+
+ pr_debug(" to fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]);
+
+ if (current->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
+ return (current->thread.fpexc_mode & PR_FP_EXC_RES) ? 1 : 0;
+ return 0;
+}
+
+static int __init spe_mathemu_init(void)
+{
+ u32 pvr, maj, min;
+
+ pvr = mfspr(SPRN_PVR);
+
+ if ((PVR_VER(pvr) == PVR_VER_E500V1) ||
+ (PVR_VER(pvr) == PVR_VER_E500V2)) {
+ maj = PVR_MAJ(pvr);
+ min = PVR_MIN(pvr);
+
+ /*
+ * E500 revision below 1.1, 2.3, 3.1, 4.1, 5.1
+ * need cpu a005 errata workaround
+ */
+ switch (maj) {
+ case 1:
+ if (min < 1)
+ have_e500_cpu_a005_erratum = 1;
+ break;
+ case 2:
+ if (min < 3)
+ have_e500_cpu_a005_erratum = 1;
+ break;
+ case 3:
+ case 4:
+ case 5:
+ if (min < 1)
+ have_e500_cpu_a005_erratum = 1;
+ break;
+ default:
+ break;
+ }
+ }
+
+ return 0;
+}
+
+module_init(spe_mathemu_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-07 22:02:42 +0000