[PATCH v5 20/21] powerpc sstep: Add support for prefixed load/stores
From: Jordan Niethe <hidden>
Date: 2020-04-06 08:49:36
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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)
Reviewed-by: Balamuruhan S <redacted>
Signed-off-by: Jordan Niethe <redacted>
---
v2: - Combine all load/store patches
- Fix the name of Type 01 instructions
- Remove sign extension flag from pstd/pld
- Rename sufx -> suffix
v3: - Move prefixed loads and stores into the switch statement
---
arch/powerpc/include/asm/sstep.h | 4 +
arch/powerpc/lib/sstep.c | 159 +++++++++++++++++++++++++++++++
2 files changed, 163 insertions(+)
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index c3ce903ac488..9b200a5f8794 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 8b285bf11218..8b6aee0ee636 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c@@ -187,6 +187,44 @@ static nokprobe_inline unsigned long xform_ea(unsigned int instr, return ea; } +/* + * 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.
@@ -1166,6 +1204,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, struct ppc_inst instr) { unsigned int opcode, ra, rb, rc, rd, spr, u; + unsigned int suffixopcode, prefixtype, prefix_r; unsigned long int imm; unsigned long int val, val2; unsigned int mb, me, sh;
@@ -2652,6 +2691,126 @@ 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 = suffix >> 26; + 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; + + /* fallthru */ + 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; + + /* fallthru */ + 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__ */ }
--
2.17.1