Commit 719272c4 authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, mm: only call early_ioremap_page_table_range_init() once 



On 32bit, before patcheset that only set page table for ram, we only
call that one time.

Now, we are calling that during every init_memory_mapping if we have holes
under max_low_pfn.

We should only call it one time after all ranges under max_low_page get
mapped just like we did before.

Also that could avoid the risk to run out of pgt_buf in BRK.

Need to update page_table_range_init() to count the pages for kmap page table
at first, and use new added alloc_low_pages() to get pages in sequence.
That will conform to the requirement that pages need to be in low to high order.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-30-git-send-email-yinghai@kernel.org


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent ddd3509d

arch/x86/mm/init.c

+5 −8
Original line number Diff line number Diff line
@@ -343,14 +343,6 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, 
		ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,

						   mr[i].page_size_mask);



#ifdef CONFIG_X86_32

	early_ioremap_page_table_range_init();



	load_cr3(swapper_pg_dir);

#endif



	__flush_tlb_all();



	add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);



	return ret >> PAGE_SHIFT;
@@ -447,7 +439,12 @@ void __init init_mem_mapping(void) 
		/* can we preseve max_low_pfn ?*/

		max_low_pfn = max_pfn;

	}

#else

	early_ioremap_page_table_range_init();

	load_cr3(swapper_pg_dir);

	__flush_tlb_all();

#endif



	early_memtest(0, max_pfn_mapped << PAGE_SHIFT);

}

arch/x86/mm/init_32.c

+41 −6
Original line number Diff line number Diff line
@@ -135,8 +135,39 @@ pte_t * __init populate_extra_pte(unsigned long vaddr) 
	return one_page_table_init(pmd) + pte_idx;

}



static unsigned long __init

page_table_range_init_count(unsigned long start, unsigned long end)

{

	unsigned long count = 0;

#ifdef CONFIG_HIGHMEM

	int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;

	int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;

	int pgd_idx, pmd_idx;

	unsigned long vaddr;



	if (pmd_idx_kmap_begin == pmd_idx_kmap_end)

		return 0;



	vaddr = start;

	pgd_idx = pgd_index(vaddr);



	for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {

		for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);

							pmd_idx++) {

			if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin &&

			    (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end)

				count++;

			vaddr += PMD_SIZE;

		}

		pmd_idx = 0;

	}

#endif

	return count;

}



static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,

					   unsigned long vaddr, pte_t *lastpte)

					   unsigned long vaddr, pte_t *lastpte,

					   void **adr)

{

#ifdef CONFIG_HIGHMEM

	/*
@@ -150,16 +181,15 @@ static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 


	if (pmd_idx_kmap_begin != pmd_idx_kmap_end

	    && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin

	    && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end

	    && ((__pa(pte) >> PAGE_SHIFT) < pgt_buf_start

		|| (__pa(pte) >> PAGE_SHIFT) >= pgt_buf_end)) {

	    && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) {

		pte_t *newpte;

		int i;



		BUG_ON(after_bootmem);

		newpte = alloc_low_page();

		newpte = *adr;

		for (i = 0; i < PTRS_PER_PTE; i++)

			set_pte(newpte + i, pte[i]);

		*adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE);



		paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);

		set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
@@ -193,6 +223,11 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 
	pgd_t *pgd;

	pmd_t *pmd;

	pte_t *pte = NULL;

	unsigned long count = page_table_range_init_count(start, end);

	void *adr = NULL;



	if (count)

		adr = alloc_low_pages(count);



	vaddr = start;

	pgd_idx = pgd_index(vaddr);
@@ -205,7 +240,7 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 
		for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);

							pmd++, pmd_idx++) {

			pte = page_table_kmap_check(one_page_table_init(pmd),

			                            pmd, vaddr, pte);

						    pmd, vaddr, pte, &adr);



			vaddr += PMD_SIZE;

		}

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