From 50b80a12e4ccff46d53b93754d817acd98bc9ae0 Mon Sep 17 00:00:00 2001 From: Jordan Niethe Date: Wed, 6 May 2020 13:40:49 +1000 Subject: [PATCH] powerpc sstep: Add support for prefixed load/stores This adds emulation support for the following prefixed integer load/stores: * Prefixed Load Byte and Zero (plbz) * Prefixed Load Halfword and Zero (plhz) * Prefixed Load Halfword Algebraic (plha) * Prefixed Load Word and Zero (plwz) * Prefixed Load Word Algebraic (plwa) * Prefixed Load Doubleword (pld) * Prefixed Store Byte (pstb) * Prefixed Store Halfword (psth) * Prefixed Store Word (pstw) * Prefixed Store Doubleword (pstd) * Prefixed Load Quadword (plq) * Prefixed Store Quadword (pstq) the follow prefixed floating-point load/stores: * Prefixed Load Floating-Point Single (plfs) * Prefixed Load Floating-Point Double (plfd) * Prefixed Store Floating-Point Single (pstfs) * Prefixed Store Floating-Point Double (pstfd) and for the following prefixed VSX load/stores: * Prefixed Load VSX Scalar Doubleword (plxsd) * Prefixed Load VSX Scalar Single-Precision (plxssp) * Prefixed Load VSX Vector [0|1] (plxv, plxv0, plxv1) * Prefixed Store VSX Scalar Doubleword (pstxsd) * Prefixed Store VSX Scalar Single-Precision (pstxssp) * Prefixed Store VSX Vector [0|1] (pstxv, pstxv0, pstxv1) Signed-off-by: Jordan Niethe Reviewed-by: Balamuruhan S [mpe: Use CONFIG_PPC64 not __powerpc64__, use get_op()] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200506034050.24806-30-jniethe5@gmail.com --- arch/powerpc/include/asm/sstep.h | 4 + arch/powerpc/lib/sstep.c | 164 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 166 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h index c3ce903..9b200a5 100644 --- a/arch/powerpc/include/asm/sstep.h +++ b/arch/powerpc/include/asm/sstep.h @@ -90,11 +90,15 @@ enum instruction_type { #define VSX_LDLEFT 4 /* load VSX register from left */ #define VSX_CHECK_VEC 8 /* check MSR_VEC not MSR_VSX for reg >= 32 */ +/* Prefixed flag, ORed in with type */ +#define PREFIXED 0x800 + /* Size field in type word */ #define SIZE(n) ((n) << 12) #define GETSIZE(w) ((w) >> 12) #define GETTYPE(t) ((t) & INSTR_TYPE_MASK) +#define GETLENGTH(t) (((t) & PREFIXED) ? 8 : 4) #define MKOP(t, f, s) ((t) | (f) | SIZE(s)) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index ecd756c..6549baa 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -13,6 +13,7 @@ #include #include #include +#include extern char system_call_common[]; @@ -188,6 +189,44 @@ static nokprobe_inline unsigned long xform_ea(unsigned int instr, } /* + * Calculate effective address for a MLS:D-form / 8LS:D-form + * prefixed instruction + */ +static nokprobe_inline unsigned long mlsd_8lsd_ea(unsigned int instr, + unsigned int suffix, + const struct pt_regs *regs) +{ + int ra, prefix_r; + unsigned int dd; + unsigned long ea, d0, d1, d; + + prefix_r = instr & (1ul << 20); + ra = (suffix >> 16) & 0x1f; + + d0 = instr & 0x3ffff; + d1 = suffix & 0xffff; + d = (d0 << 16) | d1; + + /* + * sign extend a 34 bit number + */ + dd = (unsigned int)(d >> 2); + ea = (signed int)dd; + ea = (ea << 2) | (d & 0x3); + + if (!prefix_r && ra) + ea += regs->gpr[ra]; + else if (!prefix_r && !ra) + ; /* Leave ea as is */ + else if (prefix_r && !ra) + ea += regs->nip; + else if (prefix_r && ra) + ; /* Invalid form. Should already be checked for by caller! */ + + return ea; +} + +/* * Return the largest power of 2, not greater than sizeof(unsigned long), * such that x is a multiple of it. */ @@ -1165,6 +1204,9 @@ static nokprobe_inline int trap_compare(long v1, long v2) int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, struct ppc_inst instr) { +#ifdef CONFIG_PPC64 + unsigned int suffixopcode, prefixtype, prefix_r; +#endif unsigned int opcode, ra, rb, rc, rd, spr, u; unsigned long int imm; unsigned long int val, val2; @@ -2652,6 +2694,124 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, break; } break; + case 1: /* Prefixed instructions */ + prefix_r = word & (1ul << 20); + ra = (suffix >> 16) & 0x1f; + op->update_reg = ra; + rd = (suffix >> 21) & 0x1f; + op->reg = rd; + op->val = regs->gpr[rd]; + + suffixopcode = get_op(suffix); + prefixtype = (word >> 24) & 0x3; + switch (prefixtype) { + case 0: /* Type 00 Eight-Byte Load/Store */ + if (prefix_r && ra) + break; + op->ea = mlsd_8lsd_ea(word, suffix, regs); + switch (suffixopcode) { + case 41: /* plwa */ + op->type = MKOP(LOAD, PREFIXED | SIGNEXT, 4); + break; + case 42: /* plxsd */ + op->reg = rd + 32; + op->type = MKOP(LOAD_VSX, PREFIXED, 8); + op->element_size = 8; + op->vsx_flags = VSX_CHECK_VEC; + break; + case 43: /* plxssp */ + op->reg = rd + 32; + op->type = MKOP(LOAD_VSX, PREFIXED, 4); + op->element_size = 8; + op->vsx_flags = VSX_FPCONV | VSX_CHECK_VEC; + break; + case 46: /* pstxsd */ + op->reg = rd + 32; + op->type = MKOP(STORE_VSX, PREFIXED, 8); + op->element_size = 8; + op->vsx_flags = VSX_CHECK_VEC; + break; + case 47: /* pstxssp */ + op->reg = rd + 32; + op->type = MKOP(STORE_VSX, PREFIXED, 4); + op->element_size = 8; + op->vsx_flags = VSX_FPCONV | VSX_CHECK_VEC; + break; + case 51: /* plxv1 */ + op->reg += 32; + fallthrough; + case 50: /* plxv0 */ + op->type = MKOP(LOAD_VSX, PREFIXED, 16); + op->element_size = 16; + op->vsx_flags = VSX_CHECK_VEC; + break; + case 55: /* pstxv1 */ + op->reg = rd + 32; + fallthrough; + case 54: /* pstxv0 */ + op->type = MKOP(STORE_VSX, PREFIXED, 16); + op->element_size = 16; + op->vsx_flags = VSX_CHECK_VEC; + break; + case 56: /* plq */ + op->type = MKOP(LOAD, PREFIXED, 16); + break; + case 57: /* pld */ + op->type = MKOP(LOAD, PREFIXED, 8); + break; + case 60: /* stq */ + op->type = MKOP(STORE, PREFIXED, 16); + break; + case 61: /* pstd */ + op->type = MKOP(STORE, PREFIXED, 8); + break; + } + break; + case 1: /* Type 01 Eight-Byte Register-to-Register */ + break; + case 2: /* Type 10 Modified Load/Store */ + if (prefix_r && ra) + break; + op->ea = mlsd_8lsd_ea(word, suffix, regs); + switch (suffixopcode) { + case 32: /* plwz */ + op->type = MKOP(LOAD, PREFIXED, 4); + break; + case 34: /* plbz */ + op->type = MKOP(LOAD, PREFIXED, 1); + break; + case 36: /* pstw */ + op->type = MKOP(STORE, PREFIXED, 4); + break; + case 38: /* pstb */ + op->type = MKOP(STORE, PREFIXED, 1); + break; + case 40: /* plhz */ + op->type = MKOP(LOAD, PREFIXED, 2); + break; + case 42: /* plha */ + op->type = MKOP(LOAD, PREFIXED | SIGNEXT, 2); + break; + case 44: /* psth */ + op->type = MKOP(STORE, PREFIXED, 2); + break; + case 48: /* plfs */ + op->type = MKOP(LOAD_FP, PREFIXED | FPCONV, 4); + break; + case 50: /* plfd */ + op->type = MKOP(LOAD_FP, PREFIXED, 8); + break; + case 52: /* pstfs */ + op->type = MKOP(STORE_FP, PREFIXED | FPCONV, 4); + break; + case 54: /* pstfd */ + op->type = MKOP(STORE_FP, PREFIXED, 8); + break; + } + break; + case 3: /* Type 11 Modified Register-to-Register */ + break; + } #endif /* __powerpc64__ */ } @@ -2760,7 +2920,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op) { unsigned long next_pc; - next_pc = truncate_if_32bit(regs->msr, regs->nip + 4); + next_pc = truncate_if_32bit(regs->msr, regs->nip + GETLENGTH(op->type)); switch (GETTYPE(op->type)) { case COMPUTE: if (op->type & SETREG) @@ -3205,7 +3365,7 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr) return 0; instr_done: - regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4); + regs->nip = truncate_if_32bit(regs->msr, regs->nip + GETLENGTH(op.type)); return 1; } NOKPROBE_SYMBOL(emulate_step); -- 2.7.4