ia32_support.c

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/*
 * IA32 helper functions
 *
 * 06/16/00	A. Mallick	added csd/ssd/tssd for ia32 thread context
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched.h>

#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/ia32.h>

extern unsigned long *ia32_gdt_table, *ia32_tss;

extern void die_if_kernel (char *str, struct pt_regs *regs, long err);

void
ia32_save_state (struct thread_struct *thread)
{
	unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd, tssd;

	asm ("mov %0=ar.eflag;"
	     "mov %1=ar.fsr;"
	     "mov %2=ar.fcr;"
	     "mov %3=ar.fir;"
	     "mov %4=ar.fdr;"
	     "mov %5=ar.csd;"
	     "mov %6=ar.ssd;"
	     "mov %7=ar.k1"
	     : "=r"(eflag), "=r"(fsr), "=r"(fcr), "=r"(fir), "=r"(fdr),
	       "=r"(csd), "=r"(ssd), "=r"(tssd));
	thread->eflag = eflag;
	thread->fsr = fsr;
	thread->fcr = fcr;
	thread->fir = fir;
	thread->fdr = fdr;
	thread->csd = csd;
	thread->ssd = ssd;
	thread->tssd = tssd;
	asm ("mov ar.k0=%0 ;;" :: "r"(thread->old_iob));
}

void
ia32_load_state (struct thread_struct *thread)
{
	unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd, tssd;

	eflag = thread->eflag;
	fsr = thread->fsr;
	fcr = thread->fcr;
	fir = thread->fir;
	fdr = thread->fdr;
	csd = thread->csd;
	ssd = thread->ssd;
	tssd = thread->tssd;

	asm volatile ("mov ar.eflag=%0;"
		      "mov ar.fsr=%1;"
		      "mov ar.fcr=%2;"
		      "mov ar.fir=%3;"
		      "mov ar.fdr=%4;"
		      "mov ar.csd=%5;"
		      "mov ar.ssd=%6;"
		      "mov ar.k1=%7"
		      :: "r"(eflag), "r"(fsr), "r"(fcr), "r"(fir), "r"(fdr),
		         "r"(csd), "r"(ssd), "r"(tssd));
	asm ("mov %0=ar.k0 ;;" : "=r"(thread->old_iob));
	asm ("mov ar.k0=%0 ;;" :: "r"(IA32_IOBASE));
}

/*
 * Setup IA32 GDT and TSS 
 */
void
ia32_gdt_init(void)
{
	unsigned long gdt_and_tss_page;

	/* allocate two IA-32 pages of memory: */
	gdt_and_tss_page = __get_free_pages(GFP_KERNEL,
					    (IA32_PAGE_SHIFT < PAGE_SHIFT)
					    ? 0 : (IA32_PAGE_SHIFT + 1) - PAGE_SHIFT);
	ia32_gdt_table = (unsigned long *) gdt_and_tss_page;
	ia32_tss = (unsigned long *) (gdt_and_tss_page + IA32_PAGE_SIZE);

	/* Zero the gdt and tss */
	memset((void *) gdt_and_tss_page, 0, 2*IA32_PAGE_SIZE);

	/* CS descriptor in IA-32 format */
	ia32_gdt_table[4] = IA32_SEG_DESCRIPTOR(0L, 0xBFFFFFFFL, 0xBL, 1L,
						3L, 1L, 1L, 1L, 1L);

	/* DS descriptor in IA-32 format */
	ia32_gdt_table[5] = IA32_SEG_DESCRIPTOR(0L, 0xBFFFFFFFL, 0x3L, 1L,
						3L, 1L, 1L, 1L, 1L);
}

/*
 * Handle bad IA32 interrupt via syscall 
 */
void
ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
{
	siginfo_t siginfo;

	die_if_kernel("Bad IA-32 interrupt", regs, int_num);

	siginfo.si_signo = SIGTRAP;
	siginfo.si_errno = int_num;	/* XXX is it legal to abuse si_errno like this? */
	siginfo.si_code = TRAP_BRKPT;
	force_sig_info(SIGTRAP, &siginfo, current);
}