diff options
Diffstat (limited to 'arch/s390/boot/text_dma.S')
| -rw-r--r-- | arch/s390/boot/text_dma.S | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/s390/boot/text_dma.S b/arch/s390/boot/text_dma.S new file mode 100644 index 000000000..5ff5fee02 --- /dev/null +++ b/arch/s390/boot/text_dma.S @@ -0,0 +1,156 @@ +/* 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> + + .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 + larl %r1,0f + ex 0,0(%r1) + j . +0: br %r14 + .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 _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 |