diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2016-05-03 18:03:33 +0200 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2016-05-30 13:20:04 +1000 |
| commit | b68e60e6f0d2865e961a800fb8db96a7fc6494c4 (patch) | |
| tree | b2b6f25a39c8dec9f104dd6725c4d7fafa9a35c2 /target-ppc | |
| parent | c409bc5daf88a2753968fdf473b7e4b528eb841c (diff) | |
ppc: Get out of emulation on SMT "OR" ops
Otherwise tight loops at smt_low for example, which OPAL does,
eat so much CPU that we can't boot a kernel anymore. With that,
I can boot 8 CPUs just fine with powernv.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target-ppc')
| -rw-r--r-- | target-ppc/translate.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/target-ppc/translate.c b/target-ppc/translate.c index 51f6eb11c6..fe10bf8774 100644 --- a/target-ppc/translate.c +++ b/target-ppc/translate.c @@ -1392,6 +1392,19 @@ GEN_LOGICAL2(nand, tcg_gen_nand_tl, 0x0E, PPC_INTEGER); /* nor & nor. */ GEN_LOGICAL2(nor, tcg_gen_nor_tl, 0x03, PPC_INTEGER); +#if defined(TARGET_PPC64) +static void gen_pause(DisasContext *ctx) +{ + TCGv_i32 t0 = tcg_const_i32(0); + tcg_gen_st_i32(t0, cpu_env, + -offsetof(PowerPCCPU, env) + offsetof(CPUState, halted)); + tcg_temp_free_i32(t0); + + /* Stop translation, this gives other CPUs a chance to run */ + gen_exception_err(ctx, EXCP_HLT, 1); +} +#endif /* defined(TARGET_PPC64) */ + /* or & or. */ static void gen_or(DisasContext *ctx) { @@ -1447,7 +1460,7 @@ static void gen_or(DisasContext *ctx) } break; case 7: - if (ctx->hv) { + if (ctx->hv && !ctx->pr) { /* Set process priority to very high */ prio = 7; } @@ -1464,6 +1477,10 @@ static void gen_or(DisasContext *ctx) tcg_gen_ori_tl(t0, t0, ((uint64_t)prio) << 50); gen_store_spr(SPR_PPR, t0); tcg_temp_free(t0); + /* Pause us out of TCG otherwise spin loops with smt_low + * eat too much CPU and the kernel hangs + */ + gen_pause(ctx); } #endif } @@ -1489,8 +1506,6 @@ static void gen_ori(DisasContext *ctx) target_ulong uimm = UIMM(ctx->opcode); if (rS(ctx->opcode) == rA(ctx->opcode) && uimm == 0) { - /* NOP */ - /* XXX: should handle special NOPs for POWER series */ return; } tcg_gen_ori_tl(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)], uimm); |