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Commit 9d0e59a3 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by James Bottomley
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[VOYAGER] Use modern techniques to setup and teardown low identiy mappings. 



This is a trivial and hopefully obviously correct patch to setup
and teardown the identity mappings the way the rest of arch/i386
does.

My new page table setup code will break some assumptions below so
this is my attempt to keep voyager working.

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent f3402a4e

arch/i386/mach-voyager/voyager_smp.c

+6 −32
Original line number Diff line number Diff line
@@ -536,15 +536,6 @@ do_boot_cpu(__u8 cpu) 
		& ~( voyager_extended_vic_processors

		     & voyager_allowed_boot_processors);



	/* For the 486, we can't use the 4Mb page table trick, so

	 * must map a region of memory */

#ifdef CONFIG_M486

	int i;

	unsigned long *page_table_copies = (unsigned long *)

		__get_free_page(GFP_KERNEL);

#endif

	pgd_t orig_swapper_pg_dir0;



	/* This is an area in head.S which was used to set up the

	 * initial kernel stack.  We need to alter this to give the

	 * booting CPU a new stack (taken from its idle process) */
@@ -595,24 +586,11 @@ do_boot_cpu(__u8 cpu) 
	VDEBUG(("VOYAGER SMP: Booting CPU%d at 0x%lx[%x:%x], stack %p\n", cpu, 

		(unsigned long)hijack_source.val, hijack_source.idt.Segment,

		hijack_source.idt.Offset, stack_start.esp));

	/* set the original swapper_pg_dir[0] to map 0 to 4Mb transparently

	 * (so that the booting CPU can find start_32 */

	orig_swapper_pg_dir0 = swapper_pg_dir[0];

#ifdef CONFIG_M486

	if(page_table_copies == NULL)

		panic("No free memory for 486 page tables\n");

	for(i = 0; i < PAGE_SIZE/sizeof(unsigned long); i++)

		page_table_copies[i] = (i * PAGE_SIZE) 

			| _PAGE_RW | _PAGE_USER | _PAGE_PRESENT;



	((unsigned long *)swapper_pg_dir)[0] = 

		((virt_to_phys(page_table_copies)) & PAGE_MASK)

		| _PAGE_RW | _PAGE_USER | _PAGE_PRESENT;

#else

	((unsigned long *)swapper_pg_dir)[0] = 

		(virt_to_phys(pg0) & PAGE_MASK)

		| _PAGE_RW | _PAGE_USER | _PAGE_PRESENT;

#endif



	/* init lowmem identity mapping */

	clone_pgd_range(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,

			min_t(unsigned long, KERNEL_PGD_PTRS, USER_PGD_PTRS));

	flush_tlb_all();



	if(quad_boot) {

		printk("CPU %d: non extended Quad boot\n", cpu);
@@ -655,11 +633,7 @@ do_boot_cpu(__u8 cpu) 
		udelay(100);

	}

	/* reset the page table */

	swapper_pg_dir[0] = orig_swapper_pg_dir0;

	local_flush_tlb();

#ifdef CONFIG_M486

	free_page((unsigned long)page_table_copies);

#endif

	zap_low_mappings();

	  

	if (cpu_booted_map) {

		VDEBUG(("CPU%d: Booted successfully, back in CPU %d\n",