linux_kernel/arch/powerpc/include/asm/dcr-native.h

/*
 * (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>
#include <asm/cputable.h>
#include <asm/cpu_has_feature.h>
#include <linux/stringify.h>

typedef struct {
	unsigned int base;
} dcr_host_native_t;

static inline bool dcr_map_ok_native(dcr_host_native_t host)
{
	return true;
}

#define dcr_map_native(dev, dcr_n, dcr_c) \
	((dcr_host_native_t){ .base = (dcr_n) })
#define dcr_unmap_native(host, dcr_c)		do {} while (0)
#define dcr_read_native(host, dcr_n)		mfdcr(dcr_n + host.base)
#define dcr_write_native(host, dcr_n, value)	mtdcr(dcr_n + host.base, value)

/* Table based DCR accessors */
extern void __mtdcr(unsigned int reg, unsigned int val);
extern unsigned int __mfdcr(unsigned int reg);

/* mfdcrx/mtdcrx instruction based accessors. We hand code
 * the opcodes in order not to depend on newer binutils
 */
static inline unsigned int mfdcrx(unsigned int reg)
{
	unsigned int ret;
	asm volatile(".long 0x7c000206 | (%0 << 21) | (%1 << 16)"
		     : "=r" (ret) : "r" (reg));
	return ret;
}

static inline void mtdcrx(unsigned int reg, unsigned int val)
{
	asm volatile(".long 0x7c000306 | (%0 << 21) | (%1 << 16)"
		     : : "r" (val), "r" (reg));
}

#define mfdcr(rn)						\
	({unsigned int rval;					\
	if (__builtin_constant_p(rn) && rn < 1024)		\
		asm volatile("mfdcr %0," __stringify(rn)	\
		              : "=r" (rval));			\
	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
		rval = mfdcrx(rn);				\
	else							\
		rval = __mfdcr(rn);				\
	rval;})

#define mtdcr(rn, v)						\
do {								\
	if (__builtin_constant_p(rn) && rn < 1024)		\
		asm volatile("mtdcr " __stringify(rn) ",%0"	\
			      : : "r" (v)); 			\
	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
		mtdcrx(rn, 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;

static inline unsigned __mfdcri(int base_addr, int base_data, int reg)
{
	unsigned long flags;
	unsigned int val;

	spin_lock_irqsave(&dcr_ind_lock, flags);
	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
		mtdcrx(base_addr, reg);
		val = mfdcrx(base_data);
	} else {
		__mtdcr(base_addr, reg);
		val = __mfdcr(base_data);
	}
	spin_unlock_irqrestore(&dcr_ind_lock, flags);
	return val;
}

static inline void __mtdcri(int base_addr, int base_data, int reg,
			    unsigned val)
{
	unsigned long flags;

	spin_lock_irqsave(&dcr_ind_lock, flags);
	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
		mtdcrx(base_addr, reg);
		mtdcrx(base_data, val);
	} else {
		__mtdcr(base_addr, reg);
		__mtdcr(base_data, val);
	}
	spin_unlock_irqrestore(&dcr_ind_lock, flags);
}

static inline void __dcri_clrset(int base_addr, int base_data, int reg,
				 unsigned clr, unsigned set)
{
	unsigned long flags;
	unsigned int val;

	spin_lock_irqsave(&dcr_ind_lock, flags);
	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
		mtdcrx(base_addr, reg);
		val = (mfdcrx(base_data) & ~clr) | set;
		mtdcrx(base_data, val);
	} else {
		__mtdcr(base_addr, reg);
		val = (__mfdcr(base_data) & ~clr) | set;
		__mtdcr(base_data, val);
	}
	spin_unlock_irqrestore(&dcr_ind_lock, flags);
}

#define mfdcri(base, reg)	__mfdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
					 DCRN_ ## base ## _CONFIG_DATA,	\
					 reg)

#define mtdcri(base, reg, data)	__mtdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
					 DCRN_ ## base ## _CONFIG_DATA,	\
					 reg, data)

#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## _CONFIG_ADDR,	\
							      DCRN_ ## base ## _CONFIG_DATA,	\
							      reg, clr, set)

#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_DCR_NATIVE_H */