freebsd-dev/sys/powerpc/powernv/opalcall.S
Justin Hibbits 0499e9c619 powerpc64: Use medium code model in asm files for TOC references
Summary:
With a sufficiently large TOC, it's possible to index out of range, as
the immediate load instructions only permit 16-bit indices, allowing up
to 64kB range (signed) from the base pointer.  Allow +/- 2GB range, with
the medium code model TOC accesses in asm.

Patch originally by Brandon Bergren.  The issue appears to impact ELFv2
more than ELFv1.

Reviewed by:	luporl
Differential Revision: https://reviews.freebsd.org/D19708
2019-03-29 02:38:30 +00:00

103 lines
2.5 KiB
ArmAsm

/*-
* Copyright (C) 2015 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asm.h>
GLOBAL(opal_entrypoint)
.llong 0
GLOBAL(opal_data)
.llong 0
GLOBAL(opal_msr)
.llong 0
TOC_ENTRY(opal_entrypoint)
TOC_ENTRY(opal_data)
TOC_ENTRY(opal_msr)
ASENTRY(opal_call)
/* Args:
* r3: opal token
* r4-r10 opal arguments
*/
/* Save call stuff on stack */
mflr %r0
std %r0,16(%r1)
std %r2,-16(%r1)
mfcr %r0
std %r0,8(%r1)
/* Load OPAL entry information */
mr %r0,%r3
addis %r3,%r2,TOC_REF(opal_entrypoint)@ha
ld %r3,TOC_REF(opal_entrypoint)@l(%r3)
ld %r3,0(%r3)
mtctr %r3
/* Save MSR in non-volatile scratch register and turn off translation */
std %r31,-8(%r1)
mfmsr %r31
/* Load last bits from the TOC */
addis %r3,%r2,TOC_REF(opal_msr)@ha
ld %r3,TOC_REF(opal_msr)@l(%r3)
ld %r3,0(%r3)
addis %r2,%r2,TOC_REF(opal_data)@ha
ld %r2,TOC_REF(opal_data)@l(%r2)
ld %r2,0(%r2)
mtmsrd %r3
isync
/* Shift registers over */
mr %r3,%r4
mr %r4,%r5
mr %r5,%r6
mr %r6,%r7
mr %r7,%r8
mr %r8,%r9
mr %r9,%r10
/* Call OPAL */
bctrl
/* Restore MSR */
mtmsrd %r31
isync
ld %r31,-8(%r1)
/* Restore call stuff from stack */
ld %r0,16(%r1)
mtlr %r0
ld %r2,-16(%r1)
ld %r0,8(%r1)
mtcr %r0
/* And return */
blr