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| /* |
| * Copyright (C) 2001-2004 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include <arch/pm.h> |
| #include <config.h> |
| #include <arch/types.h> |
| #include <typedefs.h> |
| #include <arch/interrupt.h> |
| #include <arch/asm.h> |
| #include <arch/context.h> |
| #include <panic.h> |
| #include <arch/mm/page.h> |
| #include <mm/heap.h> |
| #include <memstr.h> |
| #include <arch/boot/boot.h> |
| |
| /* |
| * Early ia32 configuration functions and data structures. |
| */ |
| |
| /* |
| * We have no use for segmentation so we set up flat mode. In this |
| * mode, we use, for each privilege level, two segments spanning the |
| * whole memory. One is for code and one is for data. |
| */ |
| struct descriptor gdt[GDT_ITEMS] = { |
| /* NULL descriptor */ |
| { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, |
| /* KTEXT descriptor */ |
| { 0xffff, 0, 0, AR_PRESENT | AR_CODE | DPL_KERNEL, 0xf, 0, 0, 1, 1, 0 }, |
| /* KDATA descriptor */ |
| { 0xffff, 0, 0, AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_KERNEL, 0xf, 0, 0, 1, 1, 0 }, |
| /* UTEXT descriptor */ |
| { 0xffff, 0, 0, AR_PRESENT | AR_CODE | DPL_USER, 0xf, 0, 0, 1, 1, 0 }, |
| /* UDATA descriptor */ |
| { 0xffff, 0, 0, AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER, 0xf, 0, 0, 1, 1, 0 }, |
| /* TSS descriptor - set up will be completed later */ |
| { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } |
| }; |
| |
| static struct idescriptor idt[IDT_ITEMS]; |
| |
| static struct tss tss; |
| |
| struct tss *tss_p = NULL; |
| |
| /* gdtr is changed by kmp before next CPU is initialized */ |
| struct ptr_16_32 protected_bootstrap_gdtr = { .limit = sizeof(gdt), .base = KA2PA((__address) gdt) }; |
| struct ptr_16_32 gdtr = { .limit = sizeof(gdt), .base = (__address) gdt }; |
| |
| void gdt_setbase(struct descriptor *d, __address base) |
| { |
| d->base_0_15 = base & 0xffff; |
| d->base_16_23 = ((base) >> 16) & 0xff; |
| d->base_24_31 = ((base) >> 24) & 0xff; |
| } |
| |
| void gdt_setlimit(struct descriptor *d, __u32 limit) |
| { |
| d->limit_0_15 = limit & 0xffff; |
| d->limit_16_19 = (limit >> 16) & 0xf; |
| } |
| |
| void idt_setoffset(struct idescriptor *d, __address offset) |
| { |
| /* |
| * Offset is a linear address. |
| */ |
| d->offset_0_15 = offset & 0xffff; |
| d->offset_16_31 = offset >> 16; |
| } |
| |
| void tss_initialize(struct tss *t) |
| { |
| memsetb((__address) t, sizeof(struct tss), 0); |
| } |
| |
| /* |
| * This function takes care of proper setup of IDT and IDTR. |
| */ |
| void idt_init(void) |
| { |
| struct idescriptor *d; |
| int i; |
| |
| for (i = 0; i < IDT_ITEMS; i++) { |
| d = &idt[i]; |
| |
| d->unused = 0; |
| d->selector = selector(KTEXT_DES); |
| |
| d->access = AR_PRESENT | AR_INTERRUPT; /* masking interrupt */ |
| |
| if (i == VECTOR_SYSCALL) { |
| /* |
| * The syscall interrupt gate must be calleable from userland. |
| */ |
| d->access |= DPL_USER; |
| } |
| |
| idt_setoffset(d, ((__address) interrupt_handlers) + i*interrupt_handler_size); |
| trap_register(i, null_interrupt); |
| } |
| trap_register(13, gp_fault); |
| trap_register( 7, nm_fault); |
| trap_register(12, ss_fault); |
| } |
| |
| |
| /* Clean IOPL(12,13) and NT(14) flags in EFLAGS register */ |
| static void clean_IOPL_NT_flags(void) |
| { |
| asm |
| ( |
| "pushfl;" |
| "pop %%eax;" |
| "and $0xffff8fff,%%eax;" |
| "push %%eax;" |
| "popfl;" |
| : |
| : |
| :"%eax" |
| ); |
| } |
| |
| /* Clean AM(18) flag in CR0 register */ |
| static void clean_AM_flag(void) |
| { |
| asm |
| ( |
| "mov %%cr0,%%eax;" |
| "and $0xFFFBFFFF,%%eax;" |
| "mov %%eax,%%cr0;" |
| : |
| : |
| :"%eax" |
| ); |
| } |
| |
| void pm_init(void) |
| { |
| struct descriptor *gdt_p = (struct descriptor *) gdtr.base; |
| struct ptr_16_32 idtr; |
| |
| /* |
| * Update addresses in GDT and IDT to their virtual counterparts. |
| */ |
| idtr.limit = sizeof(idt); |
| idtr.base = (__address) idt; |
| __asm__ volatile ("lgdt %0\n" : : "m" (gdtr)); |
| __asm__ volatile ("lidt %0\n" : : "m" (idtr)); |
| |
| /* |
| * Each CPU has its private GDT and TSS. |
| * All CPUs share one IDT. |
| */ |
| |
| if (config.cpu_active == 1) { |
| idt_init(); |
| /* |
| * NOTE: bootstrap CPU has statically allocated TSS, because |
| * the heap hasn't been initialized so far. |
| */ |
| tss_p = &tss; |
| } |
| else { |
| tss_p = (struct tss *) malloc(sizeof(struct tss)); |
| if (!tss_p) |
| panic("could not allocate TSS\n"); |
| } |
| |
| tss_initialize(tss_p); |
| |
| gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL; |
| gdt_p[TSS_DES].special = 1; |
| gdt_p[TSS_DES].granularity = 1; |
| |
| gdt_setbase(&gdt_p[TSS_DES], (__address) tss_p); |
| gdt_setlimit(&gdt_p[TSS_DES], sizeof(struct tss) - 1); |
| |
| /* |
| * As of this moment, the current CPU has its own GDT pointing |
| * to its own TSS. We just need to load the TR register. |
| */ |
| __asm__ volatile ("ltr %0" : : "r" ((__u16) selector(TSS_DES))); |
| |
| clean_IOPL_NT_flags(); /* Disable I/O on nonprivileged levels */ |
| clean_AM_flag(); /* Disable alignment check */ |
| } |