/*
* Copyright (c) 2006 Martin Decky
* 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.
*/
/** @addtogroup ia32xen
* @{
*/
/** @file
*/
#include <arch/pm.h>
#include <config.h>
#include <arch/types.h>
#include <arch/interrupt.h>
#include <arch/asm.h>
#include <arch/context.h>
#include <panic.h>
#include <arch/mm/page.h>
#include <mm/slab.h>
#include <memstr.h>
#include <interrupt.h>
/*
* Early ia32xen 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.
*
* One is for GS register which holds pointer to the TLS thread
* structure in it's base.
*/
descriptor_t 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 },
/* TLS descriptor */
{ 0xffff, 0, 0, AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER, 0xf, 0, 0, 1, 1, 0 },
};
static trap_info_t traps[IDT_ITEMS + 1];
static tss_t tss;
tss_t *tss_p = NULL;
/* gdtr is changed by kmp before next CPU is initialized */
ptr_16_32_t bootstrap_gdtr = { .limit = sizeof(gdt), .base = KA2PA((uintptr_t) gdt) };
ptr_16_32_t gdtr = { .limit = sizeof(gdt), .base = (uintptr_t) gdt };
void gdt_setbase(descriptor_t *d, uintptr_t base)
{
d->base_0_15 = base & 0xffff;
d->base_16_23 = ((base) >> 16) & 0xff;
d->base_24_31 = ((base) >> 24) & 0xff;
}
void gdt_setlimit(descriptor_t *d, uint32_t limit)
{
d->limit_0_15 = limit & 0xffff;
d->limit_16_19 = (limit >> 16) & 0xf;
}
void tss_initialize(tss_t *t)
{
memsetb(t, sizeof(struct tss), 0);
}
static void trap(void)
{
}
void traps_init(void)
{
index_t i;
for (i = 0; i < IDT_ITEMS; i++) {
traps[i].vector = i;
if (i == VECTOR_SYSCALL)
traps[i].flags = 3;
else
traps[i].flags = 0;
traps[i].cs = XEN_CS;
traps[i].address = trap;
}
traps[IDT_ITEMS].vector = 0;
traps[IDT_ITEMS].flags = 0;
traps[IDT_ITEMS].cs = 0;
traps[IDT_ITEMS].address = NULL;
}
/* Clean IOPL(12,13) and NT(14) flags in EFLAGS register */
static void clean_IOPL_NT_flags(void)
{
// asm volatile (
// "pushfl\n"
// "pop %%eax\n"
// "and $0xffff8fff, %%eax\n"
// "push %%eax\n"
// "popfl\n"
// : : : "eax"
// );
}
/* Clean AM(18) flag in CR0 register */
static void clean_AM_flag(void)
{
// asm volatile (
// "mov %%cr0, %%eax\n"
// "and $0xfffbffff, %%eax\n"
// "mov %%eax, %%cr0\n"
// : : : "eax"
// );
}
void pm_init(void)
{
descriptor_t *gdt_p = (descriptor_t *) gdtr.base;
// gdtr_load(&gdtr);
if (config.cpu_active == 1) {
traps_init();
xen_set_trap_table(traps);
/*
* NOTE: bootstrap CPU has statically allocated TSS, because
* the heap hasn't been initialized so far.
*/
tss_p = &tss;
} else {
tss_p
= (tss_t
*) malloc(sizeof(tss_t
), FRAME_ATOMIC
); if (!tss_p)
panic("Cannot allocate TSS.");
}
// 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 = 0;
gdt_setbase(&gdt_p[TSS_DES], (uintptr_t) tss_p);
gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE - 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.
*/
// tr_load(selector(TSS_DES));
clean_IOPL_NT_flags(); /* Disable I/O on nonprivileged levels and clear NT flag. */
clean_AM_flag(); /* Disable alignment check */
}
void set_tls_desc(uintptr_t tls)
{
ptr_16_32_t cpugdtr;
descriptor_t *gdt_p;
gdtr_store(&cpugdtr);
gdt_p = (descriptor_t *) cpugdtr.base;
gdt_setbase(&gdt_p[TLS_DES], tls);
/* Reload gdt register to update GS in CPU */
gdtr_load(&cpugdtr);
}
/** @}
*/