powerpc/sysdev/dcr-low.S

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * "Indirect" DCR access
0004  *
0005  * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
0006  */
0007
0008 #include <asm/ppc_asm.h>
0009 #include <asm/processor.h>
0010 #include <asm/bug.h>
0011 #include <asm/export.h>
0012
0013 #define DCR_ACCESS_PROLOG(table) \
0014     cmplwi  cr0,r3,1024;     \
0015     rlwinm  r3,r3,4,18,27;   \
0016     lis     r5,table@h;      \
0017     ori     r5,r5,table@l;   \
0018     add     r3,r3,r5;        \
0019     bge-    1f;      \
0020     mtctr   r3;              \
0021     bctr;            \
0022 1:  trap;            \
0023     EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;  \
0024     blr
0025
0026 _GLOBAL(__mfdcr)
0027     DCR_ACCESS_PROLOG(__mfdcr_table)
0028 EXPORT_SYMBOL(__mfdcr)
0029
0030 _GLOBAL(__mtdcr)
0031     DCR_ACCESS_PROLOG(__mtdcr_table)
0032 EXPORT_SYMBOL(__mtdcr)
0033
0034 __mfdcr_table:
0035     mfdcr  r3,0; blr
0036 __mtdcr_table:
0037     mtdcr  0,r4; blr
0038
0039 dcr     = 1
0040         .rept   1023
0041     mfdcr   r3,dcr; blr
0042     mtdcr   dcr,r4; blr
0043     dcr     = dcr + 1
0044     .endr