linux-stable/arch/s390/boot/text_dma.S
Martin Schwidefsky bf72630130 s390: use proper expoline sections for .dma code
The text_dma.S code uses its own macro to generate an inline version of an
expoline. To make it easier to identify all expolines in the kernel use a
thunk and a branch to the thunk just like the rest of the kernel code does
it.

The name of the text_dma.S expoline thunk is __dma__s390_indirect_jump_r14
and the section is named .dma.text.__s390_indirect_jump_r14.

This will be needed for the objtool support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-02 13:54:11 +02:00

184 lines
3.6 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Code that needs to run below 2 GB.
*
* Copyright IBM Corp. 2019
*/
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/sigp.h>
#ifdef CC_USING_EXPOLINE
.pushsection .dma.text.__s390_indirect_jump_r14,"axG"
__dma__s390_indirect_jump_r14:
larl %r1,0f
ex 0,0(%r1)
j .
0: br %r14
.popsection
#endif
.section .dma.text,"ax"
/*
* Simplified version of expoline thunk. The normal thunks can not be used here,
* because they might be more than 2 GB away, and not reachable by the relative
* branch. No comdat, exrl, etc. optimizations used here, because it only
* affects a few functions that are not performance-relevant.
*/
.macro BR_EX_DMA_r14
#ifdef CC_USING_EXPOLINE
jg __dma__s390_indirect_jump_r14
#else
br %r14
#endif
.endm
/*
* int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode)
*/
ENTRY(_diag14_dma)
lgr %r1,%r2
lgr %r2,%r3
lgr %r3,%r4
lhi %r5,-EIO
sam31
diag %r1,%r2,0x14
.Ldiag14_ex:
ipm %r5
srl %r5,28
.Ldiag14_fault:
sam64
lgfr %r2,%r5
BR_EX_DMA_r14
EX_TABLE_DMA(.Ldiag14_ex, .Ldiag14_fault)
ENDPROC(_diag14_dma)
/*
* int _diag210_dma(struct diag210 *addr)
*/
ENTRY(_diag210_dma)
lgr %r1,%r2
lhi %r2,-1
sam31
diag %r1,%r0,0x210
.Ldiag210_ex:
ipm %r2
srl %r2,28
.Ldiag210_fault:
sam64
lgfr %r2,%r2
BR_EX_DMA_r14
EX_TABLE_DMA(.Ldiag210_ex, .Ldiag210_fault)
ENDPROC(_diag210_dma)
/*
* int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode)
*/
ENTRY(_diag26c_dma)
lghi %r5,-EOPNOTSUPP
sam31
diag %r2,%r4,0x26c
.Ldiag26c_ex:
sam64
lgfr %r2,%r5
BR_EX_DMA_r14
EX_TABLE_DMA(.Ldiag26c_ex, .Ldiag26c_ex)
ENDPROC(_diag26c_dma)
/*
* void _diag0c_dma(struct hypfs_diag0c_entry *entry)
*/
ENTRY(_diag0c_dma)
sam31
diag %r2,%r2,0x0c
sam64
BR_EX_DMA_r14
ENDPROC(_diag0c_dma)
/*
* void _swsusp_reset_dma(void)
*/
ENTRY(_swsusp_reset_dma)
larl %r1,restart_entry
larl %r2,.Lrestart_diag308_psw
og %r1,0(%r2)
stg %r1,0(%r0)
lghi %r0,0
diag %r0,%r0,0x308
restart_entry:
lhi %r1,1
sigp %r1,%r0,SIGP_SET_ARCHITECTURE
sam64
BR_EX_DMA_r14
ENDPROC(_swsusp_reset_dma)
/*
* void _diag308_reset_dma(void)
*
* Calls diag 308 subcode 1 and continues execution
*/
ENTRY(_diag308_reset_dma)
larl %r4,.Lctlregs # Save control registers
stctg %c0,%c15,0(%r4)
lg %r2,0(%r4) # Disable lowcore protection
nilh %r2,0xefff
larl %r4,.Lctlreg0
stg %r2,0(%r4)
lctlg %c0,%c0,0(%r4)
larl %r4,.Lfpctl # Floating point control register
stfpc 0(%r4)
larl %r4,.Lprefix # Save prefix register
stpx 0(%r4)
larl %r4,.Lprefix_zero # Set prefix register to 0
spx 0(%r4)
larl %r4,.Lcontinue_psw # Save PSW flags
epsw %r2,%r3
stm %r2,%r3,0(%r4)
larl %r4,restart_part2 # Setup restart PSW at absolute 0
larl %r3,.Lrestart_diag308_psw
og %r4,0(%r3) # Save PSW
lghi %r3,0
sturg %r4,%r3 # Use sturg, because of large pages
lghi %r1,1
lghi %r0,0
diag %r0,%r1,0x308
restart_part2:
lhi %r0,0 # Load r0 with zero
lhi %r1,2 # Use mode 2 = ESAME (dump)
sigp %r1,%r0,SIGP_SET_ARCHITECTURE # Switch to ESAME mode
sam64 # Switch to 64 bit addressing mode
larl %r4,.Lctlregs # Restore control registers
lctlg %c0,%c15,0(%r4)
larl %r4,.Lfpctl # Restore floating point ctl register
lfpc 0(%r4)
larl %r4,.Lprefix # Restore prefix register
spx 0(%r4)
larl %r4,.Lcontinue_psw # Restore PSW flags
lpswe 0(%r4)
.Lcontinue:
BR_EX_DMA_r14
ENDPROC(_diag308_reset_dma)
.section .dma.data,"aw",@progbits
.align 8
.Lrestart_diag308_psw:
.long 0x00080000,0x80000000
.align 8
.Lcontinue_psw:
.quad 0,.Lcontinue
.align 8
.Lctlreg0:
.quad 0
.Lctlregs:
.rept 16
.quad 0
.endr
.Lfpctl:
.long 0
.Lprefix:
.long 0
.Lprefix_zero:
.long 0