source: trunk/hal/x86_64/core/hal_cpu.S

/*
 * hal_cpu.S - Miscellaneous CPU functions
 *
 * Copyright (c) 2017 Maxime Villard
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#define x86_ASM
#include <hal_boot.h>
#include <hal_segmentation.h>
#include <hal_register.h>
#include <hal_kentry.h>

ASM_ENTRY(lgdt)
        lgdt    (%rdi)
        /* Reload the prefetch queue */
        jmp     1f
        nop
1:      /* Reload stale selectors */
        movl    $GDT_FIXED_SEL(GDT_KDATA_SEL, SEL_KPL),%eax
        movl    %eax,%ds
        movl    %eax,%es
        movl    %eax,%ss
        ret

ASM_ENTRY(lidt)
        lidt    (%rdi)
        ret

ASM_ENTRY(ltr)
        ltr     %di
        ret

ASM_ENTRY(invlpg)
        invlpg  (%rdi)
        ret

ASM_ENTRY(sti)
        sti
        ret

ASM_ENTRY(cli)
        cli
        ret

ASM_ENTRY(rdtsc)
        xorq    %rax,%rax
        rdtsc
        shlq    $32,%rdx
        orq     %rdx,%rax
        ret

ASM_ENTRY(in8)
        movq    %rdi,%rdx
        xorq    %rax,%rax
        inb     %dx,%al
        ret

ASM_ENTRY(in16)
        movq    %rdi,%rdx
        xorq    %rax,%rax
        inw     %dx,%ax
        ret

ASM_ENTRY(out8)
        movq    %rdi,%rdx
        movq    %rsi,%rax
        outb    %al,%dx
        ret

ASM_ENTRY(out16)
        movq    %rdi,%rdx
        movq    %rsi,%rax
        outw    %ax,%dx
        ret

ASM_ENTRY(rdmsr)
        movq    %rdi,%rcx
        xorq    %rax,%rax
        rdmsr
        shlq    $32,%rdx
        orq     %rdx,%rax
        ret

ASM_ENTRY(wrmsr)
        movq    %rdi,%rcx
        movq    %rsi,%rax
        movq    %rsi,%rdx
        shrq    $32,%rdx
        wrmsr
        ret

ASM_ENTRY(mfence)
        mfence
        ret

ASM_ENTRY(rcr0)
        movq    %cr0,%rax
        ret

ASM_ENTRY(rcr2)
        movq    %cr2,%rax
        ret

ASM_ENTRY(rcr3)
        movq    %cr3,%rax
        ret

ASM_ENTRY(lcr3)
        movq    %rdi,%cr3
        ret

ASM_ENTRY(rcr4)
        movq    %cr4,%rax
        ret

ASM_ENTRY(lcr4)
        movq    %rdi,%cr4
        ret

ASM_ENTRY(cpuid)
        movq    %rbx,%r8
        movq    %rdi,%rax
        movq    %rsi,%rcx
        movq    %rdx,%rsi
        cpuid
        movl    %eax,0(%rsi)
        movl    %ebx,4(%rsi)
        movl    %ecx,8(%rsi)
        movl    %edx,12(%rsi)
        movq    %r8,%rbx
        ret

/*
 * To flush all TLB entries, we must re-set the CR4_PGE flag in %cr4.
 */
ASM_ENTRY(tlbflushg)
        movq    %cr4,%rax
        movq    %rax,%rdx
        andq    $~CR4_PGE,%rdx
        movq    %rdx,%cr4
        movq    %rax,%cr4
        ret

ASM_ENTRY(tlbflush)
        movq    %cr3,%rax
        movq    %rax,%cr3
        ret

ASM_ENTRY(clts)
        clts
        ret

ASM_ENTRY(stts)
        movq    %cr0,%rax
        orq     $CR0_TS,%rax
        movq    %rax,%cr0
        ret

ASM_ENTRY(pause)
        pause
        ret

ASM_ENTRY(wbinvd)
        wbinvd
        ret

/* -------------------------------------------------------------------------- */

ASM_ENTRY(cpu_context_switch)
        pushq   %r12
        pushq   %r13

        movq    %rdi,%r13       /* oldctx */
        movq    %rsi,%r12       /* newctx */

        /*
         * Save the current stack in %rdx, and switch to the trap frame of
         * the old thread.
         */
        movq    %rsp,%rdx
        movq    CTX_TF(%r13),%rsp
        addq    $TF_SIZE,%rsp   /* end of the structure */

        /*
         * Save the TLS intr flag, and set the new one.
         */
        movq    TLSVAR(INTR),%rax
        movq    %rax,CTX_INTR(%r13)
        movq    CTX_INTR(%r12),%rax
        movq    %rax,TLSVAR(INTR)

        /* Build the trap frame */
        movl    %ss,%eax
        pushq   %rax            /* tf_ss */
        pushq   %rdx            /* tf_rsp */
        pushfq                  /* tf_rflags */
        movl    %cs,%eax
        pushq   %rax            /* tf_cs */
        movabsq $thr_resume,%rax
        pushq   %rax            /* tf_rip */
        pushq   $0              /* tf_err */
        pushq   $T_ASTFLT       /* tf_trapno */
        INTR_SAVE_REGS

        /* Switch rsp0 */
        movq    CTX_RSP0(%r12),%rax
        movq    TLSVAR(RSP0),%rdx
        movq    %rax,(%rdx)

        /* Switch to the new trap frame */
        movq    CTX_TF(%r12),%rsp

        /*
         * Restore the context, and jump into the new thread.
         */
        INTR_RESTORE_REGS
        addq    $16,%rsp
        iretq

thr_resume:
        /*
         * Only pop %r12 and %r13, and return.
         */
        popq    %r13
        popq    %r12

        ret

/* -------------------------------------------------------------------------- */

ASM_ENTRY(atomic_cas_32)
        movl    %esi,%eax
        lock
        cmpxchgl %edx,(%rdi)
        /* %eax now contains the old value */
        ret

ASM_ENTRY(atomic_add_32)
        movl    %esi,%eax
        lock
        xaddl   %eax,(%rdi)
        /* %eax now contains the old value */
        ret

ASM_ENTRY(atomic_and_32)
        movl    (%rdi),%eax
1:
        movl    %eax,%ecx
        andl    %esi,%ecx
        lock
        cmpxchgl %ecx,(%rdi)
        jnz     1b
        /* %eax now contains the old value */
        ret

ASM_ENTRY(atomic_or_32)
        movl    (%rdi),%eax
1:
        movl    %eax,%ecx
        orl     %esi,%ecx
        lock
        cmpxchgl %ecx,(%rdi)
        jnz     1b
        /* %eax now contains the old value */
        ret