From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [kvm-unit-tests PATCH v6 17/18] powerpc/ppc64: add RTAS support Date: Wed, 24 Feb 2016 11:30:04 +1100 Message-ID: <20160224003004.GY2808@voom.fritz.box> References: <1455897503-11835-1-git-send-email-drjones@redhat.com> <1455897503-11835-18-git-send-email-drjones@redhat.com> <20160222032628.GE2808@voom.fritz.box> <20160223150355.kedljlbofrzufpzb@hawk.localdomain> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9Hhx61DPNOHVwUu9" Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, thuth@redhat.com, dgibson@redhat.com, agraf@suse.de, lvivier@redhat.com, pbonzini@redhat.com, rkrcmar@redhat.com To: Andrew Jones Return-path: Received: from ozlabs.org ([103.22.144.67]:46779 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754480AbcBXCq7 (ORCPT ); Tue, 23 Feb 2016 21:46:59 -0500 Content-Disposition: inline In-Reply-To: <20160223150355.kedljlbofrzufpzb@hawk.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: --9Hhx61DPNOHVwUu9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Feb 23, 2016 at 04:03:55PM +0100, Andrew Jones wrote: > On Mon, Feb 22, 2016 at 02:26:28PM +1100, David Gibson wrote: > > On Fri, Feb 19, 2016 at 04:58:22PM +0100, Andrew Jones wrote: > > > Add enough RTAS support to start adding RTAS commands. Just add > > > power-off for now. > > >=20 > > > Signed-off-by: Andrew Jones > > > Reviewed-by: Thomas Huth > > > Tested-by: Laurent Vivier > > > Reviewed-by: David Gibson > > > --- > > > lib/powerpc/asm/rtas.h | 26 +++++++++ > > > lib/powerpc/io.c | 2 + > > > lib/powerpc/rtas.c | 139 ++++++++++++++++++++++++++++++++++++++= ++++++++++ > > > lib/ppc64/asm/rtas.h | 1 + > > > powerpc/Makefile.common | 1 + > > > 5 files changed, 169 insertions(+) > > > create mode 100644 lib/powerpc/asm/rtas.h > > > create mode 100644 lib/powerpc/rtas.c > > > create mode 100644 lib/ppc64/asm/rtas.h > > >=20 > > > diff --git a/lib/powerpc/asm/rtas.h b/lib/powerpc/asm/rtas.h > > > new file mode 100644 > > > index 0000000000000..522225bcb6de3 > > > --- /dev/null > > > +++ b/lib/powerpc/asm/rtas.h > > > @@ -0,0 +1,26 @@ > > > +#ifndef _ASMPOWERPC_RTAS_H_ > > > +#define _ASMPOWERPC_RTAS_H_ > > > +/* > > > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > > > + * > > > + * This work is licensed under the terms of the GNU LGPL, version 2. > > > + */ > > > +#include > > > + > > > +#define RTAS_UNKNOWN_SERVICE (-1) > > > + > > > +struct rtas_args { > > > + u32 token; > > > + u32 nargs; > > > + u32 nret; > > > + u32 args[16]; > > > + u32 *rets; > > > +}; > > > + > > > +extern void rtas_init(void); > > > +extern int rtas_token(const char *service); > > > +extern int rtas_call(int token, int nargs, int nret, int *outputs, .= =2E.); > > > + > > > +extern void rtas_power_off(void); > > > + > > > +#endif /* _ASMPOWERPC_RTAS_H_ */ > > > diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c > > > index ef90946fb1131..c4c61ea8ac1cf 100644 > > > --- a/lib/powerpc/io.c > > > +++ b/lib/powerpc/io.c > > > @@ -7,6 +7,7 @@ > > > */ > > > #include > > > #include > > > +#include > > > =20 > > > extern void halt(int code); > > > extern void putchar(int c); > > > @@ -15,6 +16,7 @@ static struct spinlock print_lock; > > > =20 > > > void io_init(void) > > > { > > > + rtas_init(); > > > } > > > =20 > > > void puts(const char *s) > > > diff --git a/lib/powerpc/rtas.c b/lib/powerpc/rtas.c > > > new file mode 100644 > > > index 0000000000000..464d066d3c220 > > > --- /dev/null > > > +++ b/lib/powerpc/rtas.c > > > @@ -0,0 +1,139 @@ > > > +/* > > > + * powerpc RTAS > > > + * > > > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > > > + * > > > + * This work is licensed under the terms of the GNU LGPL, version 2. > > > + */ > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#define RTAS_BLOB_WORDS 8 > > > + > > > +#if defined(__powerpc64__) > > > +struct func_ptr { > > > + unsigned long ptr; > > > + unsigned long toc; > > > +}; > > > +static struct func_ptr rtas_entry_funcptr; > > > +#endif > > > +static u32 rtas_blob[RTAS_BLOB_WORDS]; > > > +typedef void (*rtas_entry_t)(unsigned long); > > > +static rtas_entry_t enter_rtas; > > > +static struct rtas_args rtas_args; > > > +static struct spinlock rtas_lock; > > > + > > > +static int rtas_node(void) > > > +{ > > > + int node =3D fdt_path_offset(dt_fdt(), "/rtas"); > > > + > > > + if (node < 0) { > > > + printf("%s: /rtas: %s\n", __func__, fdt_strerror(node)); > > > + abort(); > > > + } > > > + > > > + return node; > > > +} > > > + > > > +void rtas_init(void) > > > +{ > > > + bool broken_sc1 =3D hcall_have_broken_sc1(); > > > + int node =3D rtas_node(), len, words, i; > > > + const struct fdt_property *prop; > > > + u32 *data, *insns; > > > + > > > + if (!dt_available()) { > > > + printf("%s: No device tree!\n", __func__); > > > + abort(); > > > + } > > > + > > > + prop =3D fdt_get_property(dt_fdt(), node, > > > + "linux,rtas-entry", &len); > > > + if (!prop) { > > > + printf("%s: /rtas/linux,rtas-entry: %s\n", > > > + __func__, fdt_strerror(len)); > > > + abort(); > > > + } > > > + > > > + data =3D (u32 *)prop->data; > > > + insns =3D (u32 *)(unsigned long)fdt32_to_cpu(*data); > > > + > > > + prop =3D fdt_get_property(dt_fdt(), node, "rtas-size", &len); > > > + if (!prop) { > > > + printf("%s: /rtas/rtas-size: %s\n", > > > + __func__, fdt_strerror(len)); > > > + abort(); > > > + } > > > + data =3D (u32 *)prop->data; > > > + words =3D (int)fdt32_to_cpu(*data)/4; > > > + assert(words <=3D RTAS_BLOB_WORDS); > > > + > > > + for (i =3D 0; i < words; ++i) { > > > + rtas_blob[i] =3D be32_to_cpu(insns[i]); > > > + if (broken_sc1 && rtas_blob[i] =3D=3D SC1) > > > + rtas_blob[i] =3D SC1_REPLACEMENT; > > > + } > >=20 > > Hmm.. in general it's not guaranteed that you can copy around the RTAS > > blob and have it still work. But.. you're working essentially at the > > same level as SLOF here, rather than a "normal" OS and I think SLOF > > must make the same assumption. So I guess it's ok. >=20 > I can edit the instructions in place, like I was doing before, as now... I don't think it really matters. > >=20 > > > +#if defined(__powerpc64__) > >=20 > > Technically this ifdef should be based on the ABI version, rather than > > __powerpc64__, but I'm not sure if there are standard #defines for that. > >=20 > > > + rtas_entry_funcptr.ptr =3D (unsigned long)rtas_blob; > > > + enter_rtas =3D (rtas_entry_t)&rtas_entry_funcptr; > > > +#else > > > + enter_rtas =3D (rtas_entry_t)rtas_blob; > > > +#endif > >=20 > > I think you may want to have an actual coded enter_rtas function, > > rather than just constructing a function pointer around the raw blob. > > For one thing it should reduce the ugly ABI version #ifdefs. More > > importantly though, you can use it to set up the correct MSR state for > > entry into RTAS (IR, DR, EE off, big-endian, ..). At the moment all > > your code runs in a suitable MSR state to call directly into RTAS, but > > that will probably change fairly soon. >=20 > ...I see I don't need to edit all instructions wrt to endianness. The > "call RTAS with BE state", even if running LE, was something I had > missed, which means the above code (converting the BE blob to cpu > endian) was the wrong thing to do. I've now added an assembler enter_rtas > function, which doesn't do anything special yet, but I think I know what > needs to be done with it, at least for LE enablement. Right. The RTAS blob needs to be entered in BE mode, and technically in 32-bit mode as well, although the one we use in KVM will work fine in 64-bit mode as well. That does also mean it can technically clobber the upper halves of a lot of registers - see the kernel enter_rtas(). --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. 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