xref: /darwin-on-arm/xnu/osfmk/i386/commpage/commpage.h

/*
 * Copyright (c) 2003-2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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 */

#ifndef _I386_COMMPAGE_H
#define _I386_COMMPAGE_H

#ifndef	__ASSEMBLER__
#include <stdint.h>
#include <mach/boolean.h>
#include <mach/vm_types.h>
#include <machine/cpu_capabilities.h>
#endif /* __ASSEMBLER__ */

/* When trying to acquire a spinlock or mutex, we will spin in
 * user mode for awhile, before entering the kernel to relinquish.
 * MP_SPIN_TRIES is the initial value of _COMM_PAGE_SPIN_COUNT.
 * The idea is that _COMM_PAGE_SPIN_COUNT will be adjusted up or
 * down as the machine is plugged in/out, etc.
 * At present spinlocks do not use _COMM_PAGE_SPIN_COUNT.
 * They use MP_SPIN_TRIES directly.
 */
#define	MP_SPIN_TRIES	1000


/* The following macro is used to generate the 64-bit commpage address for a given
 * routine, based on its 32-bit address.  This is used in the kernel to compile
 * the 64-bit commpage.  Since the kernel can be a 32-bit object, cpu_capabilities.h
 * only defines the 32-bit address.
 */
#define	_COMM_PAGE_32_TO_64( ADDRESS )	( ADDRESS + _COMM_PAGE64_START_ADDRESS - _COMM_PAGE32_START_ADDRESS )


#ifdef	__ASSEMBLER__

#define COMMPAGE_DESCRIPTOR_NAME(label)  _commpage_ ## label

#if defined (__i386__)

#define COMMPAGE_DESCRIPTOR_FIELD_POINTER .long
#define COMMPAGE_DESCRIPTOR_REFERENCE(label) \
	.long COMMPAGE_DESCRIPTOR_NAME(label)

#elif defined (__x86_64__)

#define COMMPAGE_DESCRIPTOR_FIELD_POINTER .quad
#define COMMPAGE_DESCRIPTOR_REFERENCE(label) \
	.quad COMMPAGE_DESCRIPTOR_NAME(label)

#else
#error unsupported architecture
#endif

#define COMMPAGE_FUNCTION_START(label,codetype,alignment) \
.text								;\
.code ## codetype						;\
.align alignment, 0x90						;\
L ## label ## :

#define	COMMPAGE_DESCRIPTOR(label,address)			\
L ## label ## _end:						;\
.set L ## label ## _size, L ## label ## _end - L ## label	;\
.const_data							;\
.private_extern COMMPAGE_DESCRIPTOR_NAME(label)			;\
COMMPAGE_DESCRIPTOR_NAME(label) ## :				;\
    COMMPAGE_DESCRIPTOR_FIELD_POINTER	L ## label 		;\
    .long				L ## label ## _size	;\
    .long				address			;\
.text


/* COMMPAGE_CALL(target,from,start)
 *
 * This macro compiles a relative near call to one
 * commpage routine from another.
 * The assembler cannot handle this directly because the code
 * is not being assembled at the address at which it will execute.
 * The alternative to this macro would be to use an
 * indirect call, which is slower because the target of an
 * indirect branch is poorly predicted.
 * The macro arguments are:
 *	target = the commpage routine we are calling
 *	from   = the commpage routine we are in now
 *	start  = the label at the start of the code for this func
 * This is admitedly ugly and fragile.  Is there a better way?
 */
#define COMMPAGE_CALL(target,from,start)			\
	COMMPAGE_CALL_INTERNAL(target,from,start,__LINE__)

#define COMMPAGE_CALL_INTERNAL(target,from,start,unique)	\
	.byte 0xe8						;\
.set UNIQUEID(unique), L ## start - . + target - from - 4	;\
	.long	UNIQUEID(unique)

#define UNIQUEID(name)	L ## name

#else /* __ASSEMBLER__ */

/* Each potential commpage routine is described by one of these.
 * Note that the COMMPAGE_DESCRIPTOR macro (above), used in
 * assembly language, must agree with this.
 */

typedef	struct	commpage_descriptor	{
    void		*code_address;				// address of code
    uint32_t	 	code_length;				// length in bytes
    uint32_t		commpage_address;			// put at this address (_COMM_PAGE_BCOPY etc)
} commpage_descriptor;


/* Warning: following structure must match the layout of the commpage.  */
/* This is the data starting at _COMM_PAGE_TIME_DATA_START, ie for nanotime() and gettimeofday() */

typedef	volatile struct	commpage_time_data	{
	uint64_t	nt_tsc_base;				// _COMM_PAGE_NT_TSC_BASE
	uint32_t	nt_scale;				// _COMM_PAGE_NT_SCALE
	uint32_t	nt_shift;				// _COMM_PAGE_NT_SHIFT
	uint64_t	nt_ns_base;				// _COMM_PAGE_NT_NS_BASE
	uint32_t	nt_generation;				// _COMM_PAGE_NT_GENERATION
	uint32_t	gtod_generation;			// _COMM_PAGE_GTOD_GENERATION
	uint64_t	gtod_ns_base;				// _COMM_PAGE_GTOD_NS_BASE
	uint64_t	gtod_sec_base;				// _COMM_PAGE_GTOD_SEC_BASE
} commpage_time_data;


extern	char	*commPagePtr32;				// virt address of 32-bit commpage in kernel map
extern	char	*commPagePtr64;				// ...and of 64-bit commpage

extern	void	commpage_set_timestamp(uint64_t abstime, uint64_t secs);
extern	void	commpage_disable_timestamp( void );
extern  void	commpage_set_nanotime(uint64_t tsc_base, uint64_t ns_base, uint32_t scale, uint32_t shift);
extern	void	commpage_set_memory_pressure(unsigned int  pressure);
extern	void	commpage_set_spin_count(unsigned int  count);
extern	void	commpage_sched_gen_inc(void);
extern	void	commpage_update_active_cpus(void);

extern	uint32_t	commpage_is_in_pfz32(uint32_t);
extern	uint32_t	commpage_is_in_pfz64(addr64_t);

#endif	/* __ASSEMBLER__ */

#endif /* _I386_COMMPAGE_H */