linux/include/asm-arm/domain.h

/*
 *  linux/include/asm-arm/domain.h
 *
 *  Copyright (C) 1999 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ASM_PROC_DOMAIN_H
#define __ASM_PROC_DOMAIN_H

/*
 * Domain numbers
 *
 *  DOMAIN_IO     - domain 2 includes all IO only
 *  DOMAIN_USER   - domain 1 includes all user memory only
 *  DOMAIN_KERNEL - domain 0 includes all kernel memory only
 *
 * The domain numbering depends on whether we support 36 physical
 * address for I/O or not.  Addresses above the 32 bit boundary can
 * only be mapped using supersections and supersections can only
 * be set for domain 0.  We could just default to DOMAIN_IO as zero,
 * but there may be systems with supersection support and no 36-bit
 * addressing.  In such cases, we want to map system memory with
 * supersections to reduce TLB misses and footprint.
 *
 * 36-bit addressing and supersections are only available on
 * CPUs based on ARMv6+ or the Intel XSC3 core.
 */
#ifndef CONFIG_IO_36
#define DOMAIN_KERNEL	0
#define DOMAIN_TABLE	0
#define DOMAIN_USER	1
#define DOMAIN_IO	2
#else
#define DOMAIN_KERNEL	2
#define DOMAIN_TABLE	2
#define DOMAIN_USER	1
#define DOMAIN_IO	0
#endif

/*
 * Domain types
 */
#define DOMAIN_NOACCESS	0
#define DOMAIN_CLIENT	1
#define DOMAIN_MANAGER	3

#define domain_val(dom,type)	((type) << (2*(dom)))

#ifndef __ASSEMBLY__

#ifdef CONFIG_MMU
#define set_domain(x)					\
	do {						\
	__asm__ __volatile__(				\
	"mcr	p15, 0, %0, c3, c0	@ set domain"	\
	  : : "r" (x));					\
	isb();						\
	} while (0)

#define modify_domain(dom,type)					\
	do {							\
	struct thread_info *thread = current_thread_info();	\
	unsigned int domain = thread->cpu_domain;		\
	domain &= ~domain_val(dom, DOMAIN_MANAGER);		\
	thread->cpu_domain = domain | domain_val(dom, type);	\
	set_domain(thread->cpu_domain);				\
	} while (0)

#else
#define set_domain(x)		do { } while (0)
#define modify_domain(dom,type)	do { } while (0)
#endif

#endif
#endif /* !__ASSEMBLY__ */