linux/include/asm-powerpc/dcr-native.h
Michael Ellerman 83f34df4e7 Add dcr_host_t.base in dcr_read()/dcr_write()
Now that all users of dcr_read()/dcr_write() add the dcr_host_t.base, we
can save them the trouble and do it in dcr_read()/dcr_write().

As some background to why we just went through all this jiggery-pokery,
benh sayeth:

 Initially the goal of the dcr_read/dcr_write routines was to operate like
 mfdcr/mtdcr which take absolute DCR numbers. The reason is that on 4xx
 hardware, indirect DCR access is a pain (goes through a table of
 instructions) and it's useful to have the compiler resolve an absolute DCR
 inline.

 We decided that wasn't worth the API bastardisation since most places
 where absolute DCR values are used are low level 4xx-only code which may
 as well continue using mfdcr/mtdcr, while the new API is designed for
 device "instances" that can exist on 4xx and Axon type platforms and may
 be located at variable DCR offsets.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-10-15 14:29:49 -04:00

75 lines
2.2 KiB
C

/*
* (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _ASM_POWERPC_DCR_NATIVE_H
#define _ASM_POWERPC_DCR_NATIVE_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
typedef struct {
unsigned int base;
} dcr_host_t;
#define DCR_MAP_OK(host) (1)
#define dcr_map(dev, dcr_n, dcr_c) ((dcr_host_t){ .base = (dcr_n) })
#define dcr_unmap(host, dcr_n, dcr_c) do {} while (0)
#define dcr_read(host, dcr_n) mfdcr(dcr_n + host.base)
#define dcr_write(host, dcr_n, value) mtdcr(dcr_n + host.base, value)
/* Device Control Registers */
void __mtdcr(int reg, unsigned int val);
unsigned int __mfdcr(int reg);
#define mfdcr(rn) \
({unsigned int rval; \
if (__builtin_constant_p(rn)) \
asm volatile("mfdcr %0," __stringify(rn) \
: "=r" (rval)); \
else \
rval = __mfdcr(rn); \
rval;})
#define mtdcr(rn, v) \
do { \
if (__builtin_constant_p(rn)) \
asm volatile("mtdcr " __stringify(rn) ",%0" \
: : "r" (v)); \
else \
__mtdcr(rn, v); \
} while (0)
/* R/W of indirect DCRs make use of standard naming conventions for DCRs */
#define mfdcri(base, reg) \
({ \
mtdcr(base ## _CFGADDR, base ## _ ## reg); \
mfdcr(base ## _CFGDATA); \
})
#define mtdcri(base, reg, data) \
do { \
mtdcr(base ## _CFGADDR, base ## _ ## reg); \
mtdcr(base ## _CFGDATA, data); \
} while (0)
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_DCR_NATIVE_H */