[PATCH v8 29/30] powerpc sstep: Add support for prefixed load/stores
Jordan Niethe
jniethe5 at gmail.com
Wed May 6 13:40:49 AEST 2020
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 <bala24 at linux.ibm.com>
Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
---
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
v6: - Compile on ppc32
- Add back in + GETLENGTH(op->type)
v8: Use fallthrough; keyword
---
arch/powerpc/include/asm/sstep.h | 4 +
arch/powerpc/lib/sstep.c | 163 ++++++++++++++++++++++++++++++-
2 files changed, 165 insertions(+), 2 deletions(-)
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 ecd756c346fd..6794a7672ad5 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 +1204,9 @@ 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;
+#ifdef __powerpc64__
+ unsigned int suffixopcode, prefixtype, prefix_r;
+#endif
unsigned long int imm;
unsigned long int val, val2;
unsigned int mb, me, sh;
@@ -2652,6 +2693,124 @@ 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 = 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;
+ 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 +2919,7 @@ 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 +3364,7 @@ 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);
--
2.17.1
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