linux/include/asm-powerpc/dcr-native.h
Benjamin Herrenschmidt 0e6140a56f [POWERPC] 4xx: Improve support for 4xx indirect DCRs
Accessing indirect DCRs is done via a pair of address/data DCRs.

Such accesses are thus inherently racy, vs. interrupts, preemption
and possibly SMP if 4xx SMP cores are ever used.

This updates the mfdcri/mtdcri macros in dcr-native.h (which were
so far unused) to use a spinlock.

In addition, add some common definitions to a new dcr-regs.h file.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2007-12-23 13:12:11 -06:00

85 lines
2.6 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__
#include <linux/spinlock.h>
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_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 */
extern spinlock_t dcr_ind_lock;
#define mfdcri(base, reg) \
({ \
unsigned long flags; \
unsigned int val; \
spin_lock_irqsave(&dcr_ind_lock, flags); \
mtdcr(DCRN_ ## base ## _CONFIG_ADDR, reg); \
val = mfdcr(DCRN_ ## base ## _CONFIG_DATA); \
spin_unlock_irqrestore(&dcr_ind_lock, flags); \
val; \
})
#define mtdcri(base, reg, data) \
do { \
unsigned long flags; \
spin_lock_irqsave(&dcr_ind_lock, flags); \
mtdcr(DCRN_ ## base ## _CONFIG_ADDR, reg); \
mtdcr(DCRN_ ## base ## _CONFIG_DATA, data); \
spin_unlock_irqrestore(&dcr_ind_lock, flags); \
} while (0)
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_DCR_NATIVE_H */