[PATCH 1/6] powerpc sstep: Add maddhd, maddhdu, maddld instruction emulation
From: Sandipan Das <hidden>
Date: 2018-09-03 15:19:51
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
This adds emulation support for the following integer instructions: * Multiply-Add High Doubleword (maddhd) * Multiply-Add High Doubleword Unsigned (maddhdu) * Multiply-Add Low Doubleword (maddld) Signed-off-by: Sandipan Das <redacted> --- arch/powerpc/lib/sstep.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index d81568f783e5..b40ec18515bd 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c@@ -1169,7 +1169,7 @@ static nokprobe_inline int trap_compare(long v1, long v2) int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, unsigned int instr) { - unsigned int opcode, ra, rb, rd, spr, u; + unsigned int opcode, ra, rb, rc, rd, spr, u; unsigned long int imm; unsigned long int val, val2; unsigned int mb, me, sh;
@@ -1292,6 +1292,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, rd = (instr >> 21) & 0x1f; ra = (instr >> 16) & 0x1f; rb = (instr >> 11) & 0x1f; + rc = (instr >> 6) & 0x1f; switch (opcode) { #ifdef __powerpc64__
@@ -1305,6 +1306,38 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, goto trap; return 1; +#ifdef __powerpc64__ + case 4: + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + return -1; + + switch (instr & 0x3f) { + case 48: /* maddhd */ + asm("maddhd %0,%1,%2,%3" : "=r" (op->val) : + "r" (regs->gpr[ra]), "r" (regs->gpr[rb]), + "r" (regs->gpr[rc])); + goto compute_done; + + case 49: /* maddhdu */ + asm("maddhdu %0,%1,%2,%3" : "=r" (op->val) : + "r" (regs->gpr[ra]), "r" (regs->gpr[rb]), + "r" (regs->gpr[rc])); + goto compute_done; + + case 51: /* maddld */ + asm("maddld %0,%1,%2,%3" : "=r" (op->val) : + "r" (regs->gpr[ra]), "r" (regs->gpr[rb]), + "r" (regs->gpr[rc])); + goto compute_done; + } + + /* + * There are other instructions from ISA 3.0 with the same + * primary opcode which do not have emulation support yet. + */ + return -1; +#endif + case 7: /* mulli */ op->val = regs->gpr[ra] * (short) instr; goto compute_done;
--
2.14.4