From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 115F4C33C8C for ; Tue, 7 Jan 2020 14:18:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DA2A1208C4 for ; Tue, 7 Jan 2020 14:18:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA2A1208C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49576 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iopgM-0000by-Vg for qemu-devel@archiver.kernel.org; Tue, 07 Jan 2020 09:18:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51033) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iop8t-0001Si-0L for qemu-devel@nongnu.org; Tue, 07 Jan 2020 08:43:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iop8r-00042I-Co for qemu-devel@nongnu.org; Tue, 07 Jan 2020 08:43:30 -0500 Received: from 1.mo178.mail-out.ovh.net ([178.33.251.53]:54995) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iop8r-00040v-2j for qemu-devel@nongnu.org; Tue, 07 Jan 2020 08:43:29 -0500 Received: from player786.ha.ovh.net (unknown [10.108.16.204]) by mo178.mail-out.ovh.net (Postfix) with ESMTP id B89408B567 for ; Tue, 7 Jan 2020 14:43:26 +0100 (CET) Received: from kaod.org (deibp9eh1--blueice1n4.emea.ibm.com [195.212.29.166]) (Authenticated sender: clg@kaod.org) by player786.ha.ovh.net (Postfix) with ESMTPSA id 5BFF8E18BE24; Tue, 7 Jan 2020 13:43:16 +0000 (UTC) Subject: Re: [PATCH v2 08/10] target/ppc: Streamline calculation of RMA limit from LPCR[RMLS] To: David Gibson , qemu-devel@nongnu.org, groug@kaod.org, philmd@redhat.com References: <20200107044827.471355-1-david@gibson.dropbear.id.au> <20200107044827.471355-9-david@gibson.dropbear.id.au> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= Message-ID: Date: Tue, 7 Jan 2020 14:43:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200107044827.471355-9-david@gibson.dropbear.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Ovh-Tracer-Id: 10015442621942696742 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedufedrvdehgedguddtucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepuffvfhfhkffffgggjggtgfesthekredttdefjeenucfhrhhomhepveorughrihgtpgfnvggpifhorghtvghruceotghlgheskhgrohgurdhorhhgqeenucffohhmrghinhepghhnuhdrohhrghenucfkpheptddrtddrtddrtddpudelhedrvdduvddrvdelrdduieeinecurfgrrhgrmhepmhhouggvpehsmhhtphdqohhuthdphhgvlhhopehplhgrhigvrhejkeeirdhhrgdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomheptghlgheskhgrohgurdhorhhgpdhrtghpthhtohepqhgvmhhuqdguvghvvghlsehnohhnghhnuhdrohhrghenucevlhhushhtvghrufhiiigvpedt Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 178.33.251.53 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: aik@ozlabs.ru, Mark Cave-Ayland , qemu-ppc@nongnu.org, lvivier@redhat.com, paulus@samba.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/7/20 5:48 AM, David Gibson wrote: > Currently we use a big switch statement in ppc_hash64_update_rmls() to = work > out what the right RMA limit is based on the LPCR[RMLS] field. There's= no > formula for this - it's just an arbitrary mapping defined by the existi= ng > CPU implementations - but we can make it a bit more readable by using a > lookup table rather than a switch. In addition we can use the MiB/GiB > symbols to make it a bit clearer. >=20 > While there we add a bit of clarity and rationale to the comment about > what happens if the LPCR[RMLS] doesn't contain a valid value. >=20 > Signed-off-by: David Gibson Reviewed-by: C=C3=A9dric Le Goater > --- > target/ppc/mmu-hash64.c | 71 ++++++++++++++++++++--------------------- > 1 file changed, 35 insertions(+), 36 deletions(-) >=20 > diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c > index 127b7250ae..bb9ebeaf48 100644 > --- a/target/ppc/mmu-hash64.c > +++ b/target/ppc/mmu-hash64.c > @@ -18,6 +18,7 @@ > * License along with this library; if not, see . > */ > #include "qemu/osdep.h" > +#include "qemu/units.h" > #include "cpu.h" > #include "exec/exec-all.h" > #include "exec/helper-proto.h" > @@ -755,6 +756,39 @@ static void ppc_hash64_set_c(PowerPCCPU *cpu, hwad= dr ptex, uint64_t pte1) > stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80); > } > =20 > +static target_ulong rmls_limit(PowerPCCPU *cpu) > +{ > + CPUPPCState *env =3D &cpu->env; > + /* > + * This is the full 4 bits encoding of POWER8. Previous > + * CPUs only support a subset of these but the filtering > + * is done when writing LPCR > + */ > + const target_ulong rma_sizes[] =3D { > + [0] =3D 0, > + [1] =3D 16 * GiB, > + [2] =3D 1 * GiB, > + [3] =3D 64 * MiB, > + [4] =3D 256 * MiB, > + [5] =3D 0, > + [6] =3D 0, > + [7] =3D 128 * MiB, > + [8] =3D 32 * MiB, > + }; > + target_ulong rmls =3D (env->spr[SPR_LPCR] & LPCR_RMLS) >> LPCR_RML= S_SHIFT; > + > + if (rmls < ARRAY_SIZE(rma_sizes)) { > + return rma_sizes[rmls]; > + } else { > + /* > + * Bad value, so the OS has shot itself in the foot. Return a > + * 0-sized RMA which we expect to trigger an immediate DSI or > + * ISI > + */ > + return 0; > + } > +} > + > int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, > int rwx, int mmu_idx) > { > @@ -1004,41 +1038,6 @@ void ppc_hash64_tlb_flush_hpte(PowerPCCPU *cpu, = target_ulong ptex, > cpu->env.tlb_need_flush =3D TLB_NEED_GLOBAL_FLUSH | TLB_NEED_LOCAL= _FLUSH; > } > =20 > -static void ppc_hash64_update_rmls(PowerPCCPU *cpu) > -{ > - CPUPPCState *env =3D &cpu->env; > - uint64_t lpcr =3D env->spr[SPR_LPCR]; > - > - /* > - * This is the full 4 bits encoding of POWER8. Previous > - * CPUs only support a subset of these but the filtering > - * is done when writing LPCR > - */ > - switch ((lpcr & LPCR_RMLS) >> LPCR_RMLS_SHIFT) { > - case 0x8: /* 32MB */ > - env->rmls =3D 0x2000000ull; > - break; > - case 0x3: /* 64MB */ > - env->rmls =3D 0x4000000ull; > - break; > - case 0x7: /* 128MB */ > - env->rmls =3D 0x8000000ull; > - break; > - case 0x4: /* 256MB */ > - env->rmls =3D 0x10000000ull; > - break; > - case 0x2: /* 1GB */ > - env->rmls =3D 0x40000000ull; > - break; > - case 0x1: /* 16GB */ > - env->rmls =3D 0x400000000ull; > - break; > - default: > - /* What to do here ??? */ > - env->rmls =3D 0; > - } > -} > - > static void ppc_hash64_update_vrma(PowerPCCPU *cpu) > { > CPUPPCState *env =3D &cpu->env; > @@ -1097,7 +1096,7 @@ void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong= val) > CPUPPCState *env =3D &cpu->env; > =20 > env->spr[SPR_LPCR] =3D val & pcc->lpcr_mask; > - ppc_hash64_update_rmls(cpu); > + env->rmls =3D rmls_limit(cpu); > ppc_hash64_update_vrma(cpu); > } > =20 >=20