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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 <arch/mm/page.h> |
#include <arch/types.h> |
#include <arch/interrupt.h> |
#include <arch/asm.h> |
|
#include <config.h> |
|
#include <memstr.h> |
#include <mm/heap.h> |
#include <debug.h> |
|
/* |
* There is no segmentation in long mode 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 */ |
{ .limit_0_15 = 0xffff, |
.base_0_15 = 0, |
.base_16_23 = 0, |
.access = AR_PRESENT | AR_CODE | DPL_KERNEL | AR_READABLE , |
.limit_16_19 = 0xf, |
.available = 0, |
.longmode = 1, |
.special = 0, |
.granularity = 1, |
.base_24_31 = 0 }, |
/* KDATA descriptor */ |
{ .limit_0_15 = 0xffff, |
.base_0_15 = 0, |
.base_16_23 = 0, |
.access = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_KERNEL, |
.limit_16_19 = 0xf, |
.available = 0, |
.longmode = 0, |
.special = 0, |
.granularity = 1, |
.base_24_31 = 0 }, |
/* UTEXT descriptor */ |
{ .limit_0_15 = 0xffff, |
.base_0_15 = 0, |
.base_16_23 = 0, |
.access = AR_PRESENT | AR_CODE | DPL_USER, |
.limit_16_19 = 0xf, |
.available = 0, |
.longmode = 1, |
.special = 0, |
.granularity = 1, |
.base_24_31 = 0 }, |
/* UDATA descriptor */ |
{ .limit_0_15 = 0xffff, |
.base_0_15 = 0, |
.base_16_23 = 0, |
.access = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER, |
.limit_16_19 = 0xf, |
.available = 0, |
.longmode = 0, |
.special = 1, |
.granularity = 1, |
.base_24_31 = 0 }, |
/* KTEXT 16-bit protected */ |
{ .limit_0_15 = 0xffff, |
.base_0_15 = 0, |
.base_16_23 = 0, |
.access = AR_PRESENT | AR_CODE | DPL_KERNEL | AR_READABLE, |
.limit_16_19 = 0xf, |
.available = 0, |
.longmode = 0, |
.special = 0, |
.granularity = 1, |
.base_24_31 = 0 }, |
/* TSS descriptor - set up will be completed later, |
* on AMD64 it is 64-bit - 2 items in table */ |
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, |
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } |
}; |
|
struct ptr_16_64 gdtr = {.limit = sizeof(gdtr), .base= (__u64) &gdtr }; |
|
struct idescriptor idt[IDT_ITEMS]; |
|
static struct tss tss; |
|
/* TODO: Does not compile correctly if it does not exist ???? */ |
int __attribute__ ((section ("K_DATA_START"))) __fake; |
|
void gdt_tss_setbase(struct descriptor *d, __address base) |
{ |
struct tss_descriptor *td = (struct tss_descriptor *) d; |
|
td->base_0_15 = base & 0xffff; |
td->base_16_23 = ((base) >> 16) & 0xff; |
td->base_24_31 = ((base) >> 24) & 0xff; |
td->base_32_63 = ((base) >> 32); |
} |
|
void gdt_tss_setlimit(struct descriptor *d, __u32 limit) |
{ |
struct tss_descriptor *td = (struct tss_descriptor *) d; |
|
td->limit_0_15 = limit & 0xffff; |
td->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 & 0xffff; |
d->offset_32_63 = offset >> 32; |
} |
|
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 = idtselector(KTEXT_DES); |
|
d->present = 1; |
d->type = AR_INTERRUPT; /* masking interrupt */ |
|
if (i == VECTOR_SYSCALL) { |
/* |
* The syscall interrupt gate must be calleable from userland. |
*/ |
d->dpl |= PL_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 |
( |
"pushfq;" |
"pop %%rax;" |
"and $~(0x7000),%%rax;" |
"pushq %%rax;" |
"popfq;" |
: |
: |
:"%rax" |
); |
} |
|
/* Clean AM(18) flag in CR0 register */ |
static void clean_AM_flag(void) |
{ |
asm |
( |
"mov %%cr0,%%rax;" |
"and $~(0x40000),%%rax;" |
"mov %%rax,%%cr0;" |
: |
: |
:"%rax" |
); |
} |
|
void pm_init(void) |
{ |
struct descriptor *gdt_p = (struct descriptor *) PA2KA(gdtr.base); |
struct tss_descriptor *tss_d; |
|
/* |
* 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); |
|
tss_d = (struct tss_descriptor *) &gdt_p[TSS_DES]; |
tss_d[TSS_DES].present = 1; |
tss_d[TSS_DES].type = AR_TSS; |
tss_d[TSS_DES].dpl = PL_KERNEL; |
|
gdt_tss_setbase(&gdt_p[TSS_DES], (__address) tss_p); |
gdt_tss_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__("ltr %0" : : "r" ((__u16) gdtselector(TSS_DES))); |
|
clean_IOPL_NT_flags(); /* Disable I/O on nonprivileged levels */ |
clean_AM_flag(); /* Disable alignment check */ |
} |