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/*
* IA32 helper functions
*
* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
* Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
* Copyright (C) 2001-2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 06/16/00 A. Mallick added csd/ssd/tssd for ia32 thread context
* 02/19/01 D. Mosberger dropped tssd; it's not needed
* 09/14/01 D. Mosberger fixed memory management for gdt/tss page
* 09/29/01 D. Mosberger added ia32_load_segment_descriptors()
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/intrinsics.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include "ia32priv.h"
extern int die_if_kernel (char *str, struct pt_regs *regs, long err);
struct page *ia32_shared_page[NR_CPUS];
unsigned long *ia32_boot_gdt;
unsigned long *cpu_gdt_table[NR_CPUS];
struct page *ia32_gate_page;
static unsigned long
load_desc (u16 selector)
{
unsigned long *table, limit, index;
if (!selector)
return 0;
if (selector & IA32_SEGSEL_TI) {
table = (unsigned long *) IA32_LDT_OFFSET;
limit = IA32_LDT_ENTRIES;
} else {
table = cpu_gdt_table[smp_processor_id()];
limit = IA32_PAGE_SIZE / sizeof(ia32_boot_gdt[0]);
}
index = selector >> IA32_SEGSEL_INDEX_SHIFT;
if (index >= limit)
return 0;
return IA32_SEG_UNSCRAMBLE(table[index]);
}
void
ia32_load_segment_descriptors (struct task_struct *task)
{
struct pt_regs *regs = task_pt_regs(task);
/* Setup the segment descriptors */
regs->r24 = load_desc(regs->r16 >> 16); /* ESD */
regs->r27 = load_desc(regs->r16 >> 0); /* DSD */
regs->r28 = load_desc(regs->r16 >> 32); /* FSD */
regs->r29 = load_desc(regs->r16 >> 48); /* GSD */
regs->ar_csd = load_desc(regs->r17 >> 0); /* CSD */
regs->ar_ssd = load_desc(regs->r17 >> 16); /* SSD */
}
int
ia32_clone_tls (struct task_struct *child, struct pt_regs *childregs)
{
struct desc_struct *desc;
struct ia32_user_desc info;
int idx;
if (copy_from_user(&info, (void __user *)(childregs->r14 & 0xffffffff), sizeof(info)))
return -EFAULT;
if (LDT_empty(&info))
return -EINVAL;
idx = info.entry_number;
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
desc->a = LDT_entry_a(&info);
desc->b = LDT_entry_b(&info);
/* XXX: can this be done in a cleaner way ? */
load_TLS(&child->thread, smp_processor_id());
ia32_load_segment_descriptors(child);
load_TLS(¤t->thread, smp_processor_id());
return 0;
}
void
ia32_save_state (struct task_struct *t)
{
t->thread.eflag = ia64_getreg(_IA64_REG_AR_EFLAG);
t->thread.fsr = ia64_getreg(_IA64_REG_AR_FSR);
t->thread.fcr = ia64_getreg(_IA64_REG_AR_FCR);
t->thread.fir = ia64_getreg(_IA64_REG_AR_FIR);
t->thread.fdr = ia64_getreg(_IA64_REG_AR_FDR);
ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob);
ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1);
}
void
ia32_load_state (struct task_struct *t)
{
unsigned long eflag, fsr, fcr, fir, fdr, tssd;
struct pt_regs *regs = task_pt_regs(t);
eflag = t->thread.eflag;
fsr = t->thread.fsr;
fcr = t->thread.fcr;
fir = t->thread.fir;
fdr = t->thread.fdr;
tssd = load_desc(_TSS); /* TSSD */
ia64_setreg(_IA64_REG_AR_EFLAG, eflag);
ia64_setreg(_IA64_REG_AR_FSR, fsr);
ia64_setreg(_IA64_REG_AR_FCR, fcr);
ia64_setreg(_IA64_REG_AR_FIR, fir);
ia64_setreg(_IA64_REG_AR_FDR, fdr);
current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE);
current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD);
ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE);
ia64_set_kr(IA64_KR_TSSD, tssd);
regs->r17 = (_TSS << 48) | (_LDT << 32) | (__u32) regs->r17;
regs->r30 = load_desc(_LDT); /* LDTD */
load_TLS(&t->thread, smp_processor_id());
}
/*
* Setup IA32 GDT and TSS
*/
void
ia32_gdt_init (void)
{
int cpu = smp_processor_id();
ia32_shared_page[cpu] = alloc_page(GFP_KERNEL);
if (!ia32_shared_page[cpu])
panic("failed to allocate ia32_shared_page[%d]\n", cpu);
cpu_gdt_table[cpu] = page_address(ia32_shared_page[cpu]);
/* Copy from the boot cpu's GDT */
memcpy(cpu_gdt_table[cpu], ia32_boot_gdt, PAGE_SIZE);
}
/*
* Setup IA32 GDT and TSS
*/
static void
ia32_boot_gdt_init (void)
{
unsigned long ldt_size;
ia32_shared_page[0] = alloc_page(GFP_KERNEL);
if (!ia32_shared_page[0])
panic("failed to allocate ia32_shared_page[0]\n");
ia32_boot_gdt = page_address(ia32_shared_page[0]);
cpu_gdt_table[0] = ia32_boot_gdt;
/* CS descriptor in IA-32 (scrambled) format */
ia32_boot_gdt[__USER_CS >> 3]
= IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
0xb, 1, 3, 1, 1, 1, 1);
/* DS descriptor in IA-32 (scrambled) format */
ia32_boot_gdt[__USER_DS >> 3]
= IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
0x3, 1, 3, 1, 1, 1, 1);
ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
ia32_boot_gdt[TSS_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235,
0xb, 0, 3, 1, 1, 1, 0);
ia32_boot_gdt[LDT_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1,
0x2, 0, 3, 1, 1, 1, 0);
}
static void
ia32_gate_page_init(void)
{
unsigned long *sr;
ia32_gate_page = alloc_page(GFP_KERNEL);
sr = page_address(ia32_gate_page);
/* This is popl %eax ; movl $,%eax ; int $0x80 */
*sr++ = 0xb858 | (__IA32_NR_sigreturn << 16) | (0x80cdUL << 48);
/* This is movl $,%eax ; int $0x80 */
*sr = 0xb8 | (__IA32_NR_rt_sigreturn << 8) | (0x80cdUL << 40);
}
void
ia32_mem_init(void)
{
ia32_boot_gdt_init();
ia32_gate_page_init();
}
/*
* Handle bad IA32 interrupt via syscall
*/
void
ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
{
siginfo_t siginfo;
if (die_if_kernel("Bad IA-32 interrupt", regs, int_num))
return;
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = int_num; /* XXX is it OK to abuse si_errno like this? */
siginfo.si_flags = 0;
siginfo.si_isr = 0;
siginfo.si_addr = NULL;
siginfo.si_imm = 0;
siginfo.si_code = TRAP_BRKPT;
force_sig_info(SIGTRAP, &siginfo, current);
}
void
ia32_cpu_init (void)
{
/* initialize global ia32 state - CR0 and CR4 */
ia64_setreg(_IA64_REG_AR_CFLAG, (((ulong) IA32_CR4 << 32) | IA32_CR0));
}
static int __init
ia32_init (void)
{
#if PAGE_SHIFT > IA32_PAGE_SHIFT
{
extern struct kmem_cache *ia64_partial_page_cachep;
ia64_partial_page_cachep = kmem_cache_create("ia64_partial_page_cache",
sizeof(struct ia64_partial_page),
0, SLAB_PANIC, NULL);
}
#endif
return 0;
}
__initcall(ia32_init);
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