Commit 973dc4f3 authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, mm: Remove early_memremap workaround for page table accessing on 64bit 



We try to put page table high to make room for kdump, and at that time
those ranges are not mapped yet, and have to use ioremap to access it.

Now after patch that pre-map page table top down.
	x86, mm: setup page table in top-down
We do not need that workaround anymore.

Just use __va to return directly mapping address.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-23-git-send-email-yinghai@kernel.org


Acked-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 8d57470d

arch/x86/mm/init_64.c

+4 −34
Original line number Diff line number Diff line
@@ -340,36 +340,12 @@ static __ref void *alloc_low_page(unsigned long *phys) 
	} else

		pfn = pgt_buf_end++;



	adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);

	adr = __va(pfn * PAGE_SIZE);

	clear_page(adr);

	*phys  = pfn * PAGE_SIZE;

	return adr;

}



static __ref void *map_low_page(void *virt)

{

	void *adr;

	unsigned long phys, left;



	if (after_bootmem)

		return virt;



	phys = __pa(virt);

	left = phys & (PAGE_SIZE - 1);

	adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);

	adr = (void *)(((unsigned long)adr) | left);



	return adr;

}



static __ref void unmap_low_page(void *adr)

{

	if (after_bootmem)

		return;



	early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);

}



static unsigned long __meminit

phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,

	      pgprot_t prot)
@@ -442,10 +418,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 
		if (pmd_val(*pmd)) {

			if (!pmd_large(*pmd)) {

				spin_lock(&init_mm.page_table_lock);

				pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));

				pte = (pte_t *)pmd_page_vaddr(*pmd);

				last_map_addr = phys_pte_init(pte, address,

								end, prot);

				unmap_low_page(pte);

				spin_unlock(&init_mm.page_table_lock);

				continue;

			}
@@ -483,7 +458,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 


		pte = alloc_low_page(&pte_phys);

		last_map_addr = phys_pte_init(pte, address, end, new_prot);

		unmap_low_page(pte);



		spin_lock(&init_mm.page_table_lock);

		pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
@@ -518,10 +492,9 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 


		if (pud_val(*pud)) {

			if (!pud_large(*pud)) {

				pmd = map_low_page(pmd_offset(pud, 0));

				pmd = pmd_offset(pud, 0);

				last_map_addr = phys_pmd_init(pmd, addr, end,

							 page_size_mask, prot);

				unmap_low_page(pmd);

				__flush_tlb_all();

				continue;

			}
@@ -560,7 +533,6 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 
		pmd = alloc_low_page(&pmd_phys);

		last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,

					      prot);

		unmap_low_page(pmd);



		spin_lock(&init_mm.page_table_lock);

		pud_populate(&init_mm, pud, __va(pmd_phys));
@@ -596,17 +568,15 @@ kernel_physical_mapping_init(unsigned long start, 
			next = end;



		if (pgd_val(*pgd)) {

			pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));

			pud = (pud_t *)pgd_page_vaddr(*pgd);

			last_map_addr = phys_pud_init(pud, __pa(start),

						 __pa(end), page_size_mask);

			unmap_low_page(pud);

			continue;

		}



		pud = alloc_low_page(&pud_phys);

		last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),

						 page_size_mask);

		unmap_low_page(pud);



		spin_lock(&init_mm.page_table_lock);

		pgd_populate(&init_mm, pgd, __va(pud_phys));

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