[PATCH v4 15/16] powerpc sstep: Add support for prefixed load/stores
Balamuruhan S
bala24 at linux.ibm.com
Mon Mar 23 19:54:29 AEDT 2020
On Fri, 2020-03-20 at 16:18 +1100, Jordan Niethe wrote:
> 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 <jniethe5 at gmail.com>
LGTM,
Reviewed-by: Balamuruhan S <bala24 at linux.ibm.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
> ---
> arch/powerpc/lib/sstep.c | 159 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 159 insertions(+)
>
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index ab4c71c43c8c..daef70eb8e22 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,
> 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__ */
>
> }
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