From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [kvm-unit-tests PATCH v5 12/18] powerpc/ppc64: add hcall support and putchar Date: Fri, 19 Feb 2016 14:10:33 +1100 Message-ID: <20160219031033.GT15224@voom.fritz.box> References: <1455734459-31902-1-git-send-email-drjones@redhat.com> <1455734459-31902-13-git-send-email-drjones@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0M7E0x35R+W+EAky" 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]:48260 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423560AbcBSDhr (ORCPT ); Thu, 18 Feb 2016 22:37:47 -0500 Content-Disposition: inline In-Reply-To: <1455734459-31902-13-git-send-email-drjones@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: --0M7E0x35R+W+EAky Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 17, 2016 at 07:40:53PM +0100, Andrew Jones wrote: > Add broken sc1 detection and patching and an hcall for putchar, > to use in puts. That, along with a couple more lines in start to > prepare for C code, and a branch to main(), gets us "hello world". > Run with >=20 > qemu-system-ppc64 -M pseries \ > -bios powerpc/boot_rom.bin \ > -display none -serial stdio \ > -kernel powerpc/selftest.elf >=20 > (We're still not relocating yet, that comes in a later patch. Thus, > testing hello-world at this point requires a hacked QEMU and linking > the unit test at QEMU's kernel load address.) >=20 > Signed-off-by: Andrew Jones > Tested-by: Laurent Vivier Reviewed-by: David Gibson > --- > lib/powerpc/asm/hcall.h | 37 +++++++++++++++++++++++++++++++++++++ > lib/powerpc/hcall.c | 33 +++++++++++++++++++++++++++++++++ > lib/powerpc/io.c | 15 +++++++++++++-- > lib/ppc64/asm/hcall.h | 1 + > powerpc/Makefile.common | 2 ++ > powerpc/cstart64.S | 30 ++++++++++++++++++++++++++++++ > 6 files changed, 116 insertions(+), 2 deletions(-) > create mode 100644 lib/powerpc/asm/hcall.h > create mode 100644 lib/powerpc/hcall.c > create mode 100644 lib/ppc64/asm/hcall.h >=20 > diff --git a/lib/powerpc/asm/hcall.h b/lib/powerpc/asm/hcall.h > new file mode 100644 > index 0000000000000..750c655562549 > --- /dev/null > +++ b/lib/powerpc/asm/hcall.h > @@ -0,0 +1,37 @@ > +#ifndef _ASMPOWERPC_HCALL_H_ > +#define _ASMPOWERPC_HCALL_H_ > +/* > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > + * > + * This work is licensed under the terms of the GNU LGPL, version 2. > + */ > + > +#define SC1 0x44000022 > +#define SC1_REPLACEMENT 0x7c000268 > + > +#define H_SUCCESS 0 > +#define H_HARDWARE -1 > +#define H_FUNCTION -2 > +#define H_PRIVILEGE -3 > +#define H_PARAMETER -4 > + > +#define H_SET_DABR 0x28 > +#define H_PUT_TERM_CHAR 0x58 > + > +#ifndef __ASSEMBLY__ > +/* > + * hcall_have_broken_sc1 checks if we're on a host with a broken sc1. > + * Returns 0 if we're not. > + */ > +extern int hcall_have_broken_sc1(void); > + > +/* > + * hcall is the hypercall wrapper function. unittests may do what > + * they like, but the framework should make all hypercalls through > + * here to ensure they use a working sc1 instruction. @nr is the > + * hypercall number. > + */ > +extern unsigned long hcall(unsigned long nr, ...); > + > +#endif /* !__ASSEMBLY__ */ > +#endif /* _ASMPOWERPC_HCALL_H_ */ > diff --git a/lib/powerpc/hcall.c b/lib/powerpc/hcall.c > new file mode 100644 > index 0000000000000..cd6d26680f7cd > --- /dev/null > +++ b/lib/powerpc/hcall.c > @@ -0,0 +1,33 @@ > +/* > + * Hypercall helpers > + * > + * broken_sc1 probing/patching inspired by SLOF, see > + * SLOF:lib/libhvcall/brokensc1.c > + * > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones > + * > + * This work is licensed under the terms of the GNU LGPL, version 2. > + */ > +#include > + > +int hcall_have_broken_sc1(void) > +{ > + register unsigned long r3 asm("r3") =3D H_SET_DABR; > + register unsigned long r4 asm("r4") =3D 0; > + > + asm volatile("sc 1" > + : "=3Dr" (r3) > + : "r" (r3), "r" (r4) > + : "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12"); > + > + return r3 =3D=3D (unsigned long)H_PRIVILEGE; > +} > + > +void putchar(int c) > +{ > + unsigned long vty =3D 0; /* 0 =3D=3D default */ > + unsigned long nr_chars =3D 1; > + unsigned long chars =3D (unsigned long)c << 56; > + > + hcall(H_PUT_TERM_CHAR, vty, nr_chars, chars); > +} > diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c > index 0af45742fc900..ef90946fb1131 100644 > --- a/lib/powerpc/io.c > +++ b/lib/powerpc/io.c > @@ -6,15 +6,26 @@ > * This work is licensed under the terms of the GNU LGPL, version 2. > */ > #include > +#include > + > +extern void halt(int code); > +extern void putchar(int c); > + > +static struct spinlock print_lock; > =20 > void io_init(void) > { > } > =20 > -void puts(const char *s __unused) > +void puts(const char *s) > { > + spin_lock(&print_lock); > + while (*s) > + putchar(*s++); > + spin_unlock(&print_lock); > } > =20 > -void exit(int code __unused) > +void exit(int code) > { > + halt(code); > } > diff --git a/lib/ppc64/asm/hcall.h b/lib/ppc64/asm/hcall.h > new file mode 100644 > index 0000000000000..daabaca510cd4 > --- /dev/null > +++ b/lib/ppc64/asm/hcall.h > @@ -0,0 +1 @@ > +#include "../../powerpc/asm/hcall.h" > diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common > index 06ec96c6e546b..b21e3933d0643 100644 > --- a/powerpc/Makefile.common > +++ b/powerpc/Makefile.common > @@ -16,6 +16,7 @@ CFLAGS +=3D -ffreestanding > CFLAGS +=3D -Wextra > CFLAGS +=3D -O2 > CFLAGS +=3D -I lib -I lib/libfdt > +CFLAGS +=3D -Wa,-mregnames > =20 > asm-offsets =3D lib/$(ARCH)/asm-offsets.h > include scripts/asm-offsets.mak > @@ -24,6 +25,7 @@ cflatobjs +=3D lib/util.o > cflatobjs +=3D lib/alloc.o > cflatobjs +=3D lib/devicetree.o > cflatobjs +=3D lib/powerpc/io.o > +cflatobjs +=3D lib/powerpc/hcall.o > =20 > libgcc :=3D $(shell $(CC) $(machine) --print-libgcc-file-name) > =20 > diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S > index f90828dee1c19..1884d79871ba5 100644 > --- a/powerpc/cstart64.S > +++ b/powerpc/cstart64.S > @@ -6,14 +6,44 @@ > * This work is licensed under the terms of the GNU LGPL, version 2. > */ > #define __ASSEMBLY__ > +#include > + > +#define LOAD_REG_IMMEDIATE(reg,expr) \ > + lis reg,(expr)@highest; \ > + ori reg,reg,(expr)@higher; \ > + rldicr reg,reg,32,31; \ > + oris reg,reg,(expr)@h; \ > + ori reg,reg,(expr)@l; > + > +#define LOAD_REG_ADDR(reg,name) \ > + ld reg,name@got(r2) > =20 > .section .init > =20 > .globl start > start: > + LOAD_REG_IMMEDIATE(r1, stackptr) > + LOAD_REG_IMMEDIATE(r2, tocptr) > + > + /* patch sc1 if needed */ > + bl hcall_have_broken_sc1 > + cmpwi r3, 0 > + beq 1f > + LOAD_REG_ADDR(r3, hcall) > + LOAD_REG_IMMEDIATE(r4, SC1_REPLACEMENT) > + stw r4, 0(r3) > + > +1: bl main > + bl exit > b halt > =20 > .text > +.align 3 > + > +.globl hcall > +hcall: > + sc 1 > + blr > =20 > .globl halt > halt: --=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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