cregit-Linux how code gets into the kernel

Release 4.8 arch/sh/include/asm/processor_64.h

Directory: arch/sh/include/asm
#ifndef __ASM_SH_PROCESSOR_64_H

#define __ASM_SH_PROCESSOR_64_H

/*
 * include/asm-sh/processor_64.h
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003  Paul Mundt
 * Copyright (C) 2004  Richard Curnow
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#ifndef __ASSEMBLY__

#include <linux/compiler.h>
#include <asm/page.h>
#include <asm/types.h>
#include <cpu/registers.h>

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */

#define current_text_addr() ({ \
void *pc; \
unsigned long long __dummy = 0; \
__asm__("gettr  tr0, %1\n\t" \
        "pta    4, tr0\n\t" \
        "gettr  tr0, %0\n\t" \
        "ptabs  %1, tr0\n\t"    \
        :"=r" (pc), "=r" (__dummy) \
        : "1" (__dummy)); \
pc; })

#endif

/*
 * User space process size: 2GB - 4k.
 */

#define TASK_SIZE	0x7ffff000UL


#define STACK_TOP	TASK_SIZE

#define STACK_TOP_MAX	STACK_TOP

/* This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */

#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)

/*
 * Bit of SR register
 *
 * FD-bit:
 *     When it's set, it means the processor doesn't have right to use FPU,
 *     and it results exception when the floating operation is executed.
 *
 * IMASK-bit:
 *     Interrupt level mask
 *
 * STEP-bit:
 *     Single step bit
 *
 */
#if defined(CONFIG_SH64_SR_WATCH)

#define SR_MMU   0x84000000
#else

#define SR_MMU   0x80000000
#endif


#define SR_IMASK 0x000000f0

#define SR_FD    0x00008000

#define SR_SSTEP 0x08000000

#ifndef __ASSEMBLY__

/*
 * FPU structure and data : require 8-byte alignment as we need to access it
   with fld.p, fst.p
 */


struct sh_fpu_hard_struct {
	
unsigned long fp_regs[64];
	
unsigned int fpscr;
	/* long status; * software status information */
};

/* Dummy fpu emulator  */

struct sh_fpu_soft_struct {
	
unsigned long fp_regs[64];
	
unsigned int fpscr;
	
unsigned char lookahead;
	
unsigned long entry_pc;
};


union thread_xstate {
	
struct sh_fpu_hard_struct hardfpu;
	
struct sh_fpu_soft_struct softfpu;
	/*
         * The structure definitions only produce 32 bit alignment, yet we need
         * to access them using 64 bit load/store as well.
         */
	
unsigned long long alignment_dummy;
};


struct thread_struct {
	
unsigned long sp;
	
unsigned long pc;

	/* Various thread flags, see SH_THREAD_xxx */
	
unsigned long flags;

	/* This stores the address of the pt_regs built during a context
           switch, or of the register save area built for a kernel mode
           exception.  It is used for backtracing the stack of a sleeping task
           or one that traps in kernel mode. */
        
struct pt_regs *kregs;
	/* This stores the address of the pt_regs constructed on entry from
           user mode.  It is a fixed value over the lifetime of a process, or
           NULL for a kernel thread. */
	
struct pt_regs *uregs;

	
unsigned long address;
	/* Hardware debugging registers may come here */

	/* floating point info */
	
union thread_xstate *xstate;

	/*
         * fpu_counter contains the number of consecutive context switches
         * that the FPU is used. If this is over a threshold, the lazy fpu
         * saving becomes unlazy to save the trap. This is an unsigned char
         * so that after 256 times the counter wraps and the behavior turns
         * lazy again; this to deal with bursty apps that only use FPU for
         * a short time
         */
	
unsigned char fpu_counter;
};


#define INIT_MMAP \
{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }


#define INIT_THREAD  {                               \
        .sp             = sizeof(init_stack) +  \
                          (long) &init_stack,   \
        .pc             = 0,                    \
        .kregs          = &fake_swapper_regs,   \
        .uregs          = NULL,                 \
        .address        = 0,                    \
        .flags          = 0,                    \
}

/*
 * Do necessary setup to start up a newly executed thread.
 */

#define SR_USER (SR_MMU | SR_FD)


#define start_thread(_regs, new_pc, new_sp)			\
	_regs->sr = SR_USER;	/* User mode. */		\
        _regs->pc = new_pc - 4;	/* Compensate syscall exit */	\
        _regs->pc |= 1;		/* Set SHmedia ! */		\
        _regs->regs[18] = 0;                                    \
        _regs->regs[15] = new_sp

/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;

/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);

/* Copy and release all segment info associated with a VM */

#define copy_segments(p, mm)	do { } while (0)

#define release_segments(mm)	do { } while (0)

#define forget_segments()	do { } while (0)
/*
 * FPU lazy state save handling.
 */




static inline void disable_fpu(void)
{
	unsigned long long __dummy;

	/* Set FD flag in SR */
	__asm__ __volatile__("getcon        " __SR ", %0\n\t"
                             "or        %0, %1, %0\n\t"
                             "putcon    %0, " __SR "\n\t"
                             : "=&r" (__dummy)
                             : "r" (SR_FD));
}


Contributors
PersonTokensPropCommitsCommitProp
paul mundtpaul mundt1688.89%266.67%


adrian bunkadrian bunk211.11%133.33%


Total18100.00%3100.00%






static inline void enable_fpu(void)
{
	unsigned long long __dummy;

	/* Clear out FD flag in SR */
	__asm__ __volatile__("getcon        " __SR ", %0\n\t"
                             "and       %0, %1, %0\n\t"
                             "putcon    %0, " __SR "\n\t"
                             : "=&r" (__dummy)
                             : "r" (~SR_FD));
}


Contributors
PersonTokensPropCommitsCommitProp
paul mundtpaul mundt1688.89%266.67%


adrian bunkadrian bunk211.11%133.33%


Total18100.00%3100.00%



/* Round to nearest, no exceptions on inexact, overflow, underflow,
   zero-divide, invalid.  Configure option for whether to flush denorms to
   zero, or except if a denorm is encountered.  */
#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)

#define FPSCR_INIT  0x00040000
#else

#define FPSCR_INIT  0x00000000
#endif

#ifdef CONFIG_SH_FPU
/* Initialise the FP state of a task */
void fpinit(struct sh_fpu_hard_struct *fpregs);
#else

#define fpinit(fpregs)	do { } while (0)
#endif

extern struct task_struct *last_task_used_math;

/*
 * Return saved PC of a blocked thread.
 */

#define thread_saved_pc(tsk)	(tsk->thread.pc)

extern unsigned long get_wchan(struct task_struct *p);


#define KSTK_EIP(tsk)  ((tsk)->thread.pc)

#define KSTK_ESP(tsk)  ((tsk)->thread.sp)

#endif	/* __ASSEMBLY__ */
#endif /* __ASM_SH_PROCESSOR_64_H */

Overall Contributors
PersonTokensPropCommitsCommitProp
paul mundtpaul mundt36394.04%960.00%


david howellsdavid howells82.07%16.67%


vineet guptavineet gupta51.30%16.67%


roel kluinroel kluin41.04%16.67%


adrian bunkadrian bunk41.04%16.67%


mathias krausemathias krause10.26%16.67%


kuninori morimotokuninori morimoto10.26%16.67%


Total386100.00%15100.00%

  
Directory: arch/sh/include/asm



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