Commit 22c8ca2a authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, mm: Add alloc_low_pages(num) 



32bit kmap mapping needs pages to be used for low to high.
At this point those pages are still from pgt_buf_* from BRK, so it is
ok now.
But we want to move early_ioremap_page_table_range_init() out of
init_memory_mapping() and only call it one time later, that will
make page_table_range_init/page_table_kmap_check/alloc_low_page to
use memblock to get page.

memblock allocation for pages are from high to low.
So will get panic from page_table_kmap_check() that has BUG_ON to do
ordering checking.

This patch add alloc_low_pages to make it possible to allocate serveral
pages at first, and hand out pages one by one from low to high.

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-28-git-send-email-yinghai@kernel.org


Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 6f80b68e

arch/x86/mm/init.c

+21 −12
Original line number Original line Diff line number Diff line
@@ -25,36 +25,45 @@ unsigned long __meminitdata pgt_buf_top; 




static unsigned long min_pfn_mapped;

static unsigned long min_pfn_mapped;





__ref void *alloc_low_page(void)

__ref void *alloc_low_pages(unsigned int num)

{

{

	unsigned long pfn;

	unsigned long pfn;

	void *adr;

	int i;





#ifdef CONFIG_X86_64

#ifdef CONFIG_X86_64

	if (after_bootmem) {

	if (after_bootmem) {

		adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);

		unsigned int order;





		return adr;

		order = get_order((unsigned long)num << PAGE_SHIFT);

		return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK |

						__GFP_ZERO, order);

	}

	}

#endif

#endif





	if ((pgt_buf_end + 1) >= pgt_buf_top) {

	if ((pgt_buf_end + num) >= pgt_buf_top) {

		unsigned long ret;

		unsigned long ret;

		if (min_pfn_mapped >= max_pfn_mapped)

		if (min_pfn_mapped >= max_pfn_mapped)

			panic("alloc_low_page: ran out of memory");

			panic("alloc_low_page: ran out of memory");

		ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,

		ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,

					max_pfn_mapped << PAGE_SHIFT,

					max_pfn_mapped << PAGE_SHIFT,

					PAGE_SIZE, PAGE_SIZE);

					PAGE_SIZE * num , PAGE_SIZE);

		if (!ret)

		if (!ret)

			panic("alloc_low_page: can not alloc memory");

			panic("alloc_low_page: can not alloc memory");

		memblock_reserve(ret, PAGE_SIZE);

		memblock_reserve(ret, PAGE_SIZE * num);

		pfn = ret >> PAGE_SHIFT;

		pfn = ret >> PAGE_SHIFT;

	} else

	} else {

		pfn = pgt_buf_end++;

		pfn = pgt_buf_end;

		pgt_buf_end += num;

	}





	adr = __va(pfn * PAGE_SIZE);

	for (i = 0; i < num; i++) {

		void *adr;



		adr = __va((pfn + i) << PAGE_SHIFT);

		clear_page(adr);

		clear_page(adr);

	return adr;

	}



	return __va(pfn << PAGE_SHIFT);

}

}





/* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */

/* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */

arch/x86/mm/mm_internal.h

+5 −1
Original line number Original line Diff line number Diff line 
#ifndef __X86_MM_INTERNAL_H

#ifndef __X86_MM_INTERNAL_H

#define __X86_MM_INTERNAL_H

#define __X86_MM_INTERNAL_H





void *alloc_low_page(void);

void *alloc_low_pages(unsigned int num);

static inline void *alloc_low_page(void)

{

	return alloc_low_pages(1);

}





#endif	/* __X86_MM_INTERNAL_H */
 
#endif	/* __X86_MM_INTERNAL_H */

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