linux_dsm_epyc7002/arch/s390/include/asm/nospec-insn.h
Martin Schwidefsky 6deaa3bbca s390: extend expoline to BC instructions
The BPF JIT uses a 'b <disp>(%r<x>)' instruction in the definition
of the sk_load_word and sk_load_half functions.

Add support for branch-on-condition instructions contained in the
thunk code of an expoline.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-05-07 21:12:42 +02:00

197 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_NOSPEC_ASM_H
#define _ASM_S390_NOSPEC_ASM_H
#include <asm/alternative-asm.h>
#include <asm/asm-offsets.h>
#include <asm/dwarf.h>
#ifdef __ASSEMBLY__
#ifdef CONFIG_EXPOLINE
_LC_BR_R1 = __LC_BR_R1
/*
* The expoline macros are used to create thunks in the same format
* as gcc generates them. The 'comdat' section flag makes sure that
* the various thunks are merged into a single copy.
*/
.macro __THUNK_PROLOG_NAME name
.pushsection .text.\name,"axG",@progbits,\name,comdat
.globl \name
.hidden \name
.type \name,@function
\name:
CFI_STARTPROC
.endm
.macro __THUNK_EPILOG
CFI_ENDPROC
.popsection
.endm
.macro __THUNK_PROLOG_BR r1,r2
__THUNK_PROLOG_NAME __s390x_indirect_jump_r\r2\()use_r\r1
.endm
.macro __THUNK_PROLOG_BC d0,r1,r2
__THUNK_PROLOG_NAME __s390x_indirect_branch_\d0\()_\r2\()use_\r1
.endm
.macro __THUNK_BR r1,r2
jg __s390x_indirect_jump_r\r2\()use_r\r1
.endm
.macro __THUNK_BC d0,r1,r2
jg __s390x_indirect_branch_\d0\()_\r2\()use_\r1
.endm
.macro __THUNK_BRASL r1,r2,r3
brasl \r1,__s390x_indirect_jump_r\r3\()use_r\r2
.endm
.macro __DECODE_RR expand,reg,ruse
.set __decode_fail,1
.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \reg,%r\r1
.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \ruse,%r\r2
\expand \r1,\r2
.set __decode_fail,0
.endif
.endr
.endif
.endr
.if __decode_fail == 1
.error "__DECODE_RR failed"
.endif
.endm
.macro __DECODE_RRR expand,rsave,rtarget,ruse
.set __decode_fail,1
.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \rsave,%r\r1
.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \rtarget,%r\r2
.irp r3,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \ruse,%r\r3
\expand \r1,\r2,\r3
.set __decode_fail,0
.endif
.endr
.endif
.endr
.endif
.endr
.if __decode_fail == 1
.error "__DECODE_RRR failed"
.endif
.endm
.macro __DECODE_DRR expand,disp,reg,ruse
.set __decode_fail,1
.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \reg,%r\r1
.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
.ifc \ruse,%r\r2
\expand \disp,\r1,\r2
.set __decode_fail,0
.endif
.endr
.endif
.endr
.if __decode_fail == 1
.error "__DECODE_DRR failed"
.endif
.endm
.macro __THUNK_EX_BR reg,ruse
# Be very careful when adding instructions to this macro!
# The ALTERNATIVE replacement code has a .+10 which targets
# the "br \reg" after the code has been patched.
#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
exrl 0,555f
j .
#else
.ifc \reg,%r1
ALTERNATIVE "ex %r0,_LC_BR_R1", ".insn ril,0xc60000000000,0,.+10", 35
j .
.else
larl \ruse,555f
ex 0,0(\ruse)
j .
.endif
#endif
555: br \reg
.endm
.macro __THUNK_EX_BC disp,reg,ruse
#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
exrl 0,556f
j .
#else
larl \ruse,556f
ex 0,0(\ruse)
j .
#endif
556: b \disp(\reg)
.endm
.macro GEN_BR_THUNK reg,ruse=%r1
__DECODE_RR __THUNK_PROLOG_BR,\reg,\ruse
__THUNK_EX_BR \reg,\ruse
__THUNK_EPILOG
.endm
.macro GEN_B_THUNK disp,reg,ruse=%r1
__DECODE_DRR __THUNK_PROLOG_BC,\disp,\reg,\ruse
__THUNK_EX_BC \disp,\reg,\ruse
__THUNK_EPILOG
.endm
.macro BR_EX reg,ruse=%r1
557: __DECODE_RR __THUNK_BR,\reg,\ruse
.pushsection .s390_indirect_branches,"a",@progbits
.long 557b-.
.popsection
.endm
.macro B_EX disp,reg,ruse=%r1
558: __DECODE_DRR __THUNK_BC,\disp,\reg,\ruse
.pushsection .s390_indirect_branches,"a",@progbits
.long 558b-.
.popsection
.endm
.macro BASR_EX rsave,rtarget,ruse=%r1
559: __DECODE_RRR __THUNK_BRASL,\rsave,\rtarget,\ruse
.pushsection .s390_indirect_branches,"a",@progbits
.long 559b-.
.popsection
.endm
#else
.macro GEN_BR_THUNK reg,ruse=%r1
.endm
.macro GEN_B_THUNK disp,reg,ruse=%r1
.endm
.macro BR_EX reg,ruse=%r1
br \reg
.endm
.macro B_EX disp,reg,ruse=%r1
b \disp(\reg)
.endm
.macro BASR_EX rsave,rtarget,ruse=%r1
basr \rsave,\rtarget
.endm
#endif
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_NOSPEC_ASM_H */