thread_info.h

/* $Id: thread_info.h,v 1.1 2002/02/10 00:00:58 davem Exp $
 * thread_info.h: sparc64 low-level thread information
 *
 * Copyright (C) 2002  David S. Miller (davem@redhat.com)
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#define NSWINS		7

#define TI_FLAG_BYTE_FAULT_CODE		0
#define TI_FLAG_FAULT_CODE_SHIFT	56
#define TI_FLAG_BYTE_WSTATE		1
#define TI_FLAG_WSTATE_SHIFT		48
#define TI_FLAG_BYTE_CWP		2
#define TI_FLAG_CWP_SHIFT		40
#define TI_FLAG_BYTE_CURRENT_DS		3
#define TI_FLAG_CURRENT_DS_SHIFT	32
#define TI_FLAG_BYTE_FPDEPTH		4
#define TI_FLAG_FPDEPTH_SHIFT		24
#define TI_FLAG_BYTE_WSAVED		5
#define TI_FLAG_WSAVED_SHIFT		16

#include <asm/page.h>

#ifndef __ASSEMBLY__

#include <asm/ptrace.h>
#include <asm/types.h>

struct task_struct;
struct exec_domain;

struct thread_info {
	/* D$ line 1 */
	struct task_struct	*task;
	unsigned long		flags;
	__u8			cpu;
	__u8			fpsaved[7];
	unsigned long		ksp;

	/* D$ line 2 */
	unsigned long		fault_address;
	struct pt_regs		*kregs;
	struct exec_domain	*exec_domain;
	int			preempt_count;
	int			__pad;

	unsigned long		*utraps;

	struct reg_window 	reg_window[NSWINS];
	unsigned long 		rwbuf_stkptrs[NSWINS];

	unsigned long		gsr[7];
	unsigned long		xfsr[7];

	__u64			__user *user_cntd0;
	__u64			__user *user_cntd1;
	__u64			kernel_cntd0, kernel_cntd1;
	__u64			pcr_reg;

	__u64			cee_stuff;

	struct restart_block	restart_block;

	unsigned long		fpregs[0] __attribute__ ((aligned(64)));
};

#endif /* !(__ASSEMBLY__) */

/* offsets into the thread_info struct for assembly code access */
#define TI_TASK		0x00000000
#define TI_FLAGS	0x00000008
#define TI_FAULT_CODE	(TI_FLAGS + TI_FLAG_BYTE_FAULT_CODE)
#define TI_WSTATE	(TI_FLAGS + TI_FLAG_BYTE_WSTATE)
#define TI_CWP		(TI_FLAGS + TI_FLAG_BYTE_CWP)
#define TI_CURRENT_DS	(TI_FLAGS + TI_FLAG_BYTE_CURRENT_DS)
#define TI_FPDEPTH	(TI_FLAGS + TI_FLAG_BYTE_FPDEPTH)
#define TI_WSAVED	(TI_FLAGS + TI_FLAG_BYTE_WSAVED)
#define TI_CPU		0x00000010
#define TI_FPSAVED	0x00000011
#define TI_KSP		0x00000018
#define TI_FAULT_ADDR	0x00000020
#define TI_KREGS	0x00000028
#define TI_EXEC_DOMAIN	0x00000030
#define TI_PRE_COUNT	0x00000038
#define TI_UTRAPS	0x00000040
#define TI_REG_WINDOW	0x00000048
#define TI_RWIN_SPTRS	0x000003c8	
#define TI_GSR		0x00000400
#define TI_XFSR		0x00000438
#define TI_USER_CNTD0	0x00000470
#define TI_USER_CNTD1	0x00000478
#define TI_KERN_CNTD0	0x00000480
#define TI_KERN_CNTD1	0x00000488
#define TI_PCR		0x00000490
#define TI_CEE_STUFF	0x00000498
#define TI_RESTART_BLOCK 0x000004a0
#define TI_FPREGS	0x00000500

/* We embed this in the uppermost byte of thread_info->flags */
#define FAULT_CODE_WRITE	0x01	/* Write access, implies D-TLB	   */
#define FAULT_CODE_DTLB		0x02	/* Miss happened in D-TLB	   */
#define FAULT_CODE_ITLB		0x04	/* Miss happened in I-TLB	   */
#define FAULT_CODE_WINFIXUP	0x08	/* Miss happened during spill/fill */
#define FAULT_CODE_BLKCOMMIT	0x10	/* Use blk-commit ASI in copy_page */

#if PAGE_SHIFT == 13
#define THREAD_SIZE (2*PAGE_SIZE)
#define THREAD_SHIFT (PAGE_SHIFT + 1)
#else /* PAGE_SHIFT == 13 */
#define THREAD_SIZE PAGE_SIZE
#define THREAD_SHIFT PAGE_SHIFT
#endif /* PAGE_SHIFT == 13 */

#define PREEMPT_ACTIVE		0x4000000

/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk)				\
{							\
	.task		=	&tsk,			\
	.flags		= ((unsigned long)ASI_P) << TI_FLAG_CURRENT_DS_SHIFT,	\
	.exec_domain	=	&default_exec_domain,	\
	.preempt_count	=	1,			\
	.restart_block	= {				\
		.fn	=	do_no_restart_syscall,	\
	},						\
}

#define init_thread_info	(init_thread_union.thread_info)
#define init_stack		(init_thread_union.stack)

/* how to get the thread information struct from C */
register struct thread_info *current_thread_info_reg asm("g6");
#define current_thread_info()	(current_thread_info_reg)

/* thread information allocation */
#if PAGE_SHIFT == 13
#define __THREAD_INFO_ORDER	1
#else /* PAGE_SHIFT == 13 */
#define __THREAD_INFO_ORDER	0
#endif /* PAGE_SHIFT == 13 */

#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk)					\
({								\
	struct thread_info *ret;				\
								\
	ret = (struct thread_info *)				\
	  __get_free_pages(GFP_KERNEL, __THREAD_INFO_ORDER);	\
	if (ret)						\
		memset(ret, 0, PAGE_SIZE<<__THREAD_INFO_ORDER);	\
	ret;							\
})
#else
#define alloc_thread_info(tsk) \
	((struct thread_info *)__get_free_pages(GFP_KERNEL, __THREAD_INFO_ORDER))
#endif

#define free_thread_info(ti) \
	free_pages((unsigned long)(ti),__THREAD_INFO_ORDER)

#define __thread_flag_byte_ptr(ti)	\
	((unsigned char *)(&((ti)->flags)))
#define __cur_thread_flag_byte_ptr	__thread_flag_byte_ptr(current_thread_info())

#define get_thread_fault_code()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FAULT_CODE])
#define set_thread_fault_code(val)	(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FAULT_CODE] = (val))
#define get_thread_wstate()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSTATE])
#define set_thread_wstate(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSTATE] = (val))
#define get_thread_cwp()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CWP])
#define set_thread_cwp(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CWP] = (val))
#define get_thread_current_ds()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS])
#define set_thread_current_ds(val)	(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_CURRENT_DS] = (val))
#define get_thread_fpdepth()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH])
#define set_thread_fpdepth(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_FPDEPTH] = (val))
#define get_thread_wsaved()		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSAVED])
#define set_thread_wsaved(val)		(__cur_thread_flag_byte_ptr[TI_FLAG_BYTE_WSAVED] = (val))

#endif /* !(__ASSEMBLY__) */

/*
 * Thread information flags, only 16 bits are available as we encode
 * other values into the upper 6 bytes.
 *
 * On trap return we need to test several values:
 *
 * user:	need_resched, notify_resume, sigpending, wsaved, perfctr
 * kernel:	fpdepth
 *
 * So to check for work in the kernel case we simply load the fpdepth
 * byte out of the flags and test it.  For the user case we encode the
 * lower 3 bytes of flags as follows:
 *	----------------------------------------
 *	| wsaved | flags byte 1 | flags byte 2 |
 *	----------------------------------------
 * This optimizes the user test into:
 *	ldx		[%g6 + TI_FLAGS], REG1
 *	sethi		%hi(_TIF_USER_WORK_MASK), REG2
 *	or		REG2, %lo(_TIF_USER_WORK_MASK), REG2
 *	andcc		REG1, REG2, %g0
 *	be,pt		no_work_to_do
 *	 nop
 */
#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
#define TIF_SIGPENDING		2	/* signal pending */
#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
#define TIF_PERFCTR		4	/* performance counters active */
#define TIF_UNALIGNED		5	/* allowed to do unaligned accesses */
#define TIF_NEWSIGNALS		6	/* wants new-style signals */
#define TIF_32BIT		7	/* 32-bit binary */
#define TIF_NEWCHILD		8	/* just-spawned child process */
/* TIF_* value 9 is available */
#define TIF_POLLING_NRFLAG	10
#define TIF_SYSCALL_SUCCESS	11
/* NOTE: Thread flags >= 12 should be ones we have no interest
 *       in using in assembly, else we can't use the mask as
 *       an immediate value in instructions such as andcc.
 */
#define TIF_ABI_PENDING		12
#define TIF_MEMDIE		13

#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
#define _TIF_PERFCTR		(1<<TIF_PERFCTR)
#define _TIF_UNALIGNED		(1<<TIF_UNALIGNED)
#define _TIF_NEWSIGNALS		(1<<TIF_NEWSIGNALS)
#define _TIF_32BIT		(1<<TIF_32BIT)
#define _TIF_NEWCHILD		(1<<TIF_NEWCHILD)
#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
#define _TIF_ABI_PENDING	(1<<TIF_ABI_PENDING)
#define _TIF_SYSCALL_SUCCESS	(1<<TIF_SYSCALL_SUCCESS)

#define _TIF_USER_WORK_MASK	((0xff << TI_FLAG_WSAVED_SHIFT) | \
				 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
				  _TIF_NEED_RESCHED | _TIF_PERFCTR))

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */