Commit 8ae3a5a8 authored by Jan Beulich's avatar Jan Beulich Committed by Ingo Molnar
Browse files

x86: fix 1:1 mapping init on 64-bit (memory hotplug case) 



While I don't have a hotplug capable system at hand, I think two issues need
fixing:

- pud_phys (in kernel_physical_ampping_init()) would remain uninitialized in
  the after_bootmem case

- the locking done just around phys_pmd_{init,update}() would leave out pgd
  updates, and it was needlessly covering code portions that do allocations
  (perhaps using a more friendly gfp value in alloc_low_page() would then be
  possible)

Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 38cc1c3d

arch/x86/mm/init_64.c

+18 −14
Original line number Diff line number Diff line
@@ -336,9 +336,12 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 
		}



		if (pmd_val(*pmd)) {

			if (!pmd_large(*pmd))

			if (!pmd_large(*pmd)) {

				spin_lock(&init_mm.page_table_lock);

				last_map_addr = phys_pte_update(pmd, address,

								end);

				spin_unlock(&init_mm.page_table_lock);

			}

			/* Count entries we're using from level2_ident_pgt */

			if (start == 0)

				pages++;
@@ -347,8 +350,10 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 


		if (page_size_mask & (1<<PG_LEVEL_2M)) {

			pages++;

			spin_lock(&init_mm.page_table_lock);

			set_pte((pte_t *)pmd,

				pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));

			spin_unlock(&init_mm.page_table_lock);

			last_map_addr = (address & PMD_MASK) + PMD_SIZE;

			continue;

		}
@@ -357,7 +362,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 
		last_map_addr = phys_pte_init(pte, address, end);

		unmap_low_page(pte);



		spin_lock(&init_mm.page_table_lock);

		pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));

		spin_unlock(&init_mm.page_table_lock);

	}

	update_page_count(PG_LEVEL_2M, pages);

	return last_map_addr;
@@ -370,9 +377,7 @@ phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, 
	pmd_t *pmd = pmd_offset(pud, 0);

	unsigned long last_map_addr;



	spin_lock(&init_mm.page_table_lock);

	last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask);

	spin_unlock(&init_mm.page_table_lock);

	__flush_tlb_all();

	return last_map_addr;

}
@@ -408,20 +413,21 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 


		if (page_size_mask & (1<<PG_LEVEL_1G)) {

			pages++;

			spin_lock(&init_mm.page_table_lock);

			set_pte((pte_t *)pud,

				pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));

			spin_unlock(&init_mm.page_table_lock);

			last_map_addr = (addr & PUD_MASK) + PUD_SIZE;

			continue;

		}



		pmd = alloc_low_page(&pmd_phys);



		spin_lock(&init_mm.page_table_lock);

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

		unmap_low_page(pmd);



		spin_lock(&init_mm.page_table_lock);

		pud_populate(&init_mm, pud, __va(pmd_phys));

		spin_unlock(&init_mm.page_table_lock);



	}

	__flush_tlb_all();

	update_page_count(PG_LEVEL_1G, pages);
@@ -513,16 +519,14 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start, 
			continue;

		}



		if (after_bootmem)

			pud = pud_offset(pgd, start & PGDIR_MASK);

		else

		pud = alloc_low_page(&pud_phys);



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

						 page_size_mask);

		unmap_low_page(pud);

		pgd_populate(&init_mm, pgd_offset_k(start),

			     __va(pud_phys));



		spin_lock(&init_mm.page_table_lock);

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

		spin_unlock(&init_mm.page_table_lock);

	}



	return last_map_addr;

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