thread.h

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/*
 * Copyright (c) 2017 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

 
#ifndef ZEPHYR_INCLUDE_ARCH_X86_IA32_THREAD_H_
#define ZEPHYR_INCLUDE_ARCH_X86_IA32_THREAD_H_

#if defined(CONFIG_EAGER_FPU_SHARING) || defined(CONFIG_LAZY_FPU_SHARING)
#ifdef CONFIG_X86_SSE
#define FP_REG_SET_ALIGN  16
#else
#define FP_REG_SET_ALIGN  4
#endif
#else
/* Unused, no special alignment requirements, use default alignment for
 * char buffers on this arch
 */
#define FP_REG_SET_ALIGN  1
#endif /* CONFIG_*_FP_SHARING */
 
/*
 * Bits for _thread_arch.flags, see their use in intstub.S et al.
 */
 
#define X86_THREAD_FLAG_INT 0x01
#define X86_THREAD_FLAG_EXC 0x02
#define X86_THREAD_FLAG_ALL (X86_THREAD_FLAG_INT | X86_THREAD_FLAG_EXC)
 
#ifndef _ASMLANGUAGE
#include <stdint.h>
#include <zephyr/arch/x86/mmustructs.h>
 
/*
 * The following structure defines the set of 'non-volatile' integer registers.
 * These registers must be preserved by a called C function.  These are the
 * only registers that need to be saved/restored when a cooperative context
 * switch occurs.
 */
 
struct _callee_saved {
        unsigned long esp;
 
        /*
         * The EBP, EBX, ESI and EDI registers are also considered
         * non-volatile, i.e. callee-save, but their values are pushed onto
         * the stack rather than stored in the TCS structure.
         */
 
};
 
typedef struct _callee_saved _callee_saved_t;
 
/*
 * The macros CONFIG_{LAZY|EAGER}_FPU_SHARING shall be set to indicate that the
 * saving/restoring of the traditional x87 floating point (and MMX) registers
 * are supported by the kernel's context swapping code. The macro
 * CONFIG_X86_SSE shall _also_ be set if saving/restoring of the XMM
 * registers is also supported in the kernel's context swapping code.
 */
 
#if defined(CONFIG_EAGER_FPU_SHARING) || defined(CONFIG_LAZY_FPU_SHARING)
 
/* definition of a single x87 (floating point / MMX) register */
 
typedef struct s_FpReg {
        unsigned char reg[10]; /* 80 bits: ST[0-7] */
} tFpReg;
 
/*
 * The following is the "normal" floating point register save area, or
 * more accurately the save area required by the 'fnsave' and 'frstor'
 * instructions.  The structure matches the layout described in the
 * "Intel(r) 64 and IA-32 Architectures Software Developer's Manual
 * Volume 1: Basic Architecture": Protected Mode x87 FPU State Image in
 * Memory, 32-Bit Format.
 */
 
typedef struct s_FpRegSet {  /* # of bytes: name of register */
        unsigned short fcw;      /* 2  : x87 FPU control word */
        unsigned short pad1;     /* 2  : N/A */
        unsigned short fsw;      /* 2  : x87 FPU status word */
        unsigned short pad2;     /* 2  : N/A */
        unsigned short ftw;      /* 2  : x87 FPU tag word */
        unsigned short pad3;     /* 2  : N/A */
        unsigned int fpuip;      /* 4  : x87 FPU instruction pointer offset */
        unsigned short cs;       /* 2  : x87 FPU instruction pointer selector */
        unsigned short fop : 11; /* 2  : x87 FPU opcode */
        unsigned short pad4 : 5; /*    : 5 bits = 00000 */
        unsigned int fpudp;      /* 4  : x87 FPU instr operand ptr offset */
        unsigned short ds;       /* 2  : x87 FPU instr operand ptr selector */
        unsigned short pad5;     /* 2  : N/A */
        tFpReg fpReg[8];         /* 80 : ST0 -> ST7 */
} tFpRegSet __aligned(FP_REG_SET_ALIGN);
 
#ifdef CONFIG_X86_SSE
 
/* definition of a single x87 (floating point / MMX) register */
 
typedef struct s_FpRegEx {
        unsigned char reg[10];  /* 80 bits: ST[0-7] or MM[0-7] */
        unsigned char rsrvd[6]; /* 48 bits: reserved */
} tFpRegEx;
 
/* definition of a single XMM register */
 
typedef struct s_XmmReg {
        unsigned char reg[16]; /* 128 bits: XMM[0-7] */
} tXmmReg;
 
/*
 * The following is the "extended" floating point register save area, or
 * more accurately the save area required by the 'fxsave' and 'fxrstor'
 * instructions.  The structure matches the layout described in the
 * "Intel 64 and IA-32 Architectures Software Developer's Manual
 * Volume 2A: Instruction Set Reference, A-M", except for the bytes from offset
 * 464 to 511 since these "are available to software use. The processor does
 * not write to bytes 464:511 of an FXSAVE area".
 *
 * This structure must be aligned on a 16 byte boundary when the instructions
 * fxsave/fxrstor are used to write/read the data to/from the structure.
 */
 
typedef struct s_FpRegSetEx /* # of bytes: name of register */
{
        unsigned short fcw;     /* 2  : x87 FPU control word */
        unsigned short fsw;     /* 2  : x87 FPU status word */
        unsigned char ftw;      /* 1  : x87 FPU abridged tag word */
        unsigned char rsrvd0;   /* 1  : reserved */
        unsigned short fop;     /* 2  : x87 FPU opcode */
        unsigned int fpuip;     /* 4  : x87 FPU instruction pointer offset */
        unsigned short cs;      /* 2  : x87 FPU instruction pointer selector */
        unsigned short rsrvd1;  /* 2  : reserved */
        unsigned int fpudp;     /* 4  : x87 FPU instr operand ptr offset */
        unsigned short ds;      /* 2  : x87 FPU instr operand ptr selector */
        unsigned short rsrvd2;  /* 2  : reserved */
        unsigned int mxcsr;     /* 4  : MXCSR register state */
        unsigned int mxcsrMask; /* 4  : MXCSR register mask */
        tFpRegEx fpReg[8];      /* 128 : x87 FPU/MMX registers */
        tXmmReg xmmReg[8];      /* 128 : XMM registers */
        unsigned char rsrvd3[176]; /* 176 : reserved */
} tFpRegSetEx __aligned(FP_REG_SET_ALIGN);
 
#else /* CONFIG_X86_SSE == 0 */
 
typedef struct s_FpRegSetEx {
} tFpRegSetEx;
 
#endif /* CONFIG_X86_SSE == 0 */
 
#else /* !CONFIG_LAZY_FPU_SHARING && !CONFIG_EAGER_FPU_SHARING */
 
/* empty floating point register definition */
 
typedef struct s_FpRegSet {
} tFpRegSet;
 
typedef struct s_FpRegSetEx {
} tFpRegSetEx;
 
#endif /* CONFIG_LAZY_FPU_SHARING || CONFIG_EAGER_FPU_SHARING */
 
/*
 * The following structure defines the set of 'volatile' x87 FPU/MMX/SSE
 * registers.  These registers need not be preserved by a called C function.
 * Given that they are not preserved across function calls, they must be
 * save/restored (along with s_coopFloatReg) when a preemptive context
 * switch occurs.
 */
 
typedef struct s_preempFloatReg {
        union {
                /* threads with K_FP_REGS utilize this format */
                tFpRegSet fpRegs;
                /* threads with K_SSE_REGS utilize this format */
                tFpRegSetEx fpRegsEx;
        } floatRegsUnion;
} tPreempFloatReg;
 
/*
 * The thread control structure definition.  It contains the
 * various fields to manage a _single_ thread. The TCS will be aligned
 * to the appropriate architecture specific boundary via the
 * arch_new_thread() call.
 */
 
struct _thread_arch {
        uint8_t flags;
 
#ifdef CONFIG_USERSPACE
#ifndef CONFIG_X86_COMMON_PAGE_TABLE
        /* Physical address of the page tables used by this thread */
        uintptr_t ptables;
#endif /* CONFIG_X86_COMMON_PAGE_TABLE */
 
        /* Initial privilege mode stack pointer when doing a system call.
         * Un-set for supervisor threads.
         */
        char *psp;
#endif
 
#if defined(CONFIG_LAZY_FPU_SHARING)
        /*
         * Nested exception count to maintain setting of EXC_ACTIVE flag across
         * outermost exception.  EXC_ACTIVE is used by z_swap() lazy FP
         * save/restore and by debug tools.
         */
        unsigned excNestCount; /* nested exception count */
#endif /* CONFIG_LAZY_FPU_SHARING */
 
        tPreempFloatReg preempFloatReg; /* volatile float register storage */
 
#ifdef CONFIG_HW_SHADOW_STACK
        long *shstk_addr;
        long *shstk_base;
        size_t shstk_size;
#endif
};
 
typedef struct _thread_arch _thread_arch_t;
 
#endif /* _ASMLANGUAGE */
 
#endif /* ZEPHYR_INCLUDE_ARCH_X86_IA32_THREAD_H_ */