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463f36c76f
The DMA code section of the decompressor must be compiled with expolines
if Spectre V2 mitigation has been enabled for the decompressed kernel.
This is required because although the decompressor's image contains
the DMA code section, it is handed over to the decompressed kernel for use.
Because the DMA code is already slow w/o expolines, use expolines always
regardless whether the decompressed kernel is using them or not. This
simplifies the DMA code by dropping the conditional compilation of
expolines.
Fixes: bf72630130 ("s390: use proper expoline sections for .dma code")
Cc: <stable@vger.kernel.org> # 5.2
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
157 lines
3.1 KiB
ArmAsm
157 lines
3.1 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Code that needs to run below 2 GB.
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*
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* Copyright IBM Corp. 2019
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*/
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#include <linux/linkage.h>
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#include <asm/errno.h>
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#include <asm/sigp.h>
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.section .dma.text,"ax"
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/*
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* Simplified version of expoline thunk. The normal thunks can not be used here,
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* because they might be more than 2 GB away, and not reachable by the relative
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* branch. No comdat, exrl, etc. optimizations used here, because it only
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* affects a few functions that are not performance-relevant.
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*/
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.macro BR_EX_DMA_r14
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larl %r1,0f
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ex 0,0(%r1)
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j .
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0: br %r14
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.endm
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/*
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* int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode)
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*/
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ENTRY(_diag14_dma)
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lgr %r1,%r2
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lgr %r2,%r3
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lgr %r3,%r4
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lhi %r5,-EIO
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sam31
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diag %r1,%r2,0x14
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.Ldiag14_ex:
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ipm %r5
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srl %r5,28
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.Ldiag14_fault:
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sam64
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lgfr %r2,%r5
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BR_EX_DMA_r14
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EX_TABLE_DMA(.Ldiag14_ex, .Ldiag14_fault)
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ENDPROC(_diag14_dma)
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/*
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* int _diag210_dma(struct diag210 *addr)
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*/
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ENTRY(_diag210_dma)
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lgr %r1,%r2
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lhi %r2,-1
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sam31
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diag %r1,%r0,0x210
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.Ldiag210_ex:
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ipm %r2
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srl %r2,28
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.Ldiag210_fault:
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sam64
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lgfr %r2,%r2
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BR_EX_DMA_r14
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EX_TABLE_DMA(.Ldiag210_ex, .Ldiag210_fault)
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ENDPROC(_diag210_dma)
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/*
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* int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode)
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*/
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ENTRY(_diag26c_dma)
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lghi %r5,-EOPNOTSUPP
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sam31
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diag %r2,%r4,0x26c
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.Ldiag26c_ex:
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sam64
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lgfr %r2,%r5
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BR_EX_DMA_r14
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EX_TABLE_DMA(.Ldiag26c_ex, .Ldiag26c_ex)
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ENDPROC(_diag26c_dma)
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/*
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* void _diag0c_dma(struct hypfs_diag0c_entry *entry)
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*/
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ENTRY(_diag0c_dma)
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sam31
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diag %r2,%r2,0x0c
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sam64
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BR_EX_DMA_r14
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ENDPROC(_diag0c_dma)
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/*
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* void _diag308_reset_dma(void)
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*
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* Calls diag 308 subcode 1 and continues execution
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*/
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ENTRY(_diag308_reset_dma)
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larl %r4,.Lctlregs # Save control registers
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stctg %c0,%c15,0(%r4)
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lg %r2,0(%r4) # Disable lowcore protection
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nilh %r2,0xefff
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larl %r4,.Lctlreg0
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stg %r2,0(%r4)
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lctlg %c0,%c0,0(%r4)
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larl %r4,.Lfpctl # Floating point control register
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stfpc 0(%r4)
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larl %r4,.Lprefix # Save prefix register
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stpx 0(%r4)
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larl %r4,.Lprefix_zero # Set prefix register to 0
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spx 0(%r4)
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larl %r4,.Lcontinue_psw # Save PSW flags
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epsw %r2,%r3
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stm %r2,%r3,0(%r4)
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larl %r4,restart_part2 # Setup restart PSW at absolute 0
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larl %r3,.Lrestart_diag308_psw
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og %r4,0(%r3) # Save PSW
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lghi %r3,0
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sturg %r4,%r3 # Use sturg, because of large pages
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lghi %r1,1
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lghi %r0,0
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diag %r0,%r1,0x308
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restart_part2:
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lhi %r0,0 # Load r0 with zero
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lhi %r1,2 # Use mode 2 = ESAME (dump)
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sigp %r1,%r0,SIGP_SET_ARCHITECTURE # Switch to ESAME mode
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sam64 # Switch to 64 bit addressing mode
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larl %r4,.Lctlregs # Restore control registers
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lctlg %c0,%c15,0(%r4)
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larl %r4,.Lfpctl # Restore floating point ctl register
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lfpc 0(%r4)
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larl %r4,.Lprefix # Restore prefix register
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spx 0(%r4)
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larl %r4,.Lcontinue_psw # Restore PSW flags
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lpswe 0(%r4)
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.Lcontinue:
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BR_EX_DMA_r14
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ENDPROC(_diag308_reset_dma)
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.section .dma.data,"aw",@progbits
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.align 8
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.Lrestart_diag308_psw:
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.long 0x00080000,0x80000000
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.align 8
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.Lcontinue_psw:
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.quad 0,.Lcontinue
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.align 8
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.Lctlreg0:
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.quad 0
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.Lctlregs:
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.rept 16
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.quad 0
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.endr
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.Lfpctl:
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.long 0
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.Lprefix:
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.long 0
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.Lprefix_zero:
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.long 0
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