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Commit b7cfda9f authored by Russell King's avatar Russell King Committed by Russell King
Browse files

ARM: Fix pfn_valid() for sparse memory 



On OMAP platforms, some people want to declare to segment up the memory
between the kernel and a separate application such that there is a hole
in the middle of the memory as far as Linux is concerned.  However,
they want to be able to mmap() the hole.

This currently causes problems, because update_mmu_cache() thinks that
there are valid struct pages for the "hole".  Fix this by making
pfn_valid() slightly more expensive, by checking whether the PFN is
contained within the meminfo array.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Tested-by: default avatarKhasim Syed Mohammed <khasim@ti.com>
parent 5eb38f44

arch/arm/include/asm/memory.h

+0 −17
Original line number Diff line number Diff line
@@ -212,7 +212,6 @@ static inline __deprecated void *bus_to_virt(unsigned long x) 
 *

 *  page_to_pfn(page)	convert a struct page * to a PFN number

 *  pfn_to_page(pfn)	convert a _valid_ PFN number to struct page *

 *  pfn_valid(pfn)	indicates whether a PFN number is valid

 *

 *  virt_to_page(k)	convert a _valid_ virtual address to struct page *

 *  virt_addr_valid(k)	indicates whether a virtual address is valid
@@ -221,10 +220,6 @@ static inline __deprecated void *bus_to_virt(unsigned long x) 


#define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET



#ifndef CONFIG_SPARSEMEM

#define pfn_valid(pfn)		((pfn) >= PHYS_PFN_OFFSET && (pfn) < (PHYS_PFN_OFFSET + max_mapnr))

#endif



#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)

#define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
@@ -241,18 +236,6 @@ static inline __deprecated void *bus_to_virt(unsigned long x) 
#define arch_pfn_to_nid(pfn)	PFN_TO_NID(pfn)

#define arch_local_page_offset(pfn, nid) LOCAL_MAP_NR((pfn) << PAGE_SHIFT)



#define pfn_valid(pfn)						\

	({							\

		unsigned int nid = PFN_TO_NID(pfn);		\

		int valid = nid < MAX_NUMNODES;			\

		if (valid) {					\

			pg_data_t *node = NODE_DATA(nid);	\

			valid = (pfn - node->node_start_pfn) <	\

				node->node_spanned_pages;	\

		}						\

		valid;						\

	})



#define virt_to_page(kaddr)					\

	(ADDR_TO_MAPBASE(kaddr) + LOCAL_MAP_NR(kaddr))

arch/arm/include/asm/page.h

+4 −0
Original line number Diff line number Diff line
@@ -194,6 +194,10 @@ typedef unsigned long pgprot_t; 


typedef struct page *pgtable_t;



#ifndef CONFIG_SPARSEMEM

extern int pfn_valid(unsigned long);

#endif



#include <asm/memory.h>



#endif /* !__ASSEMBLY__ */

arch/arm/mm/init.c

+32 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/mman.h>

#include <linux/nodemask.h>

#include <linux/initrd.h>

#include <linux/sort.h>

#include <linux/highmem.h>



#include <asm/mach-types.h>
@@ -349,12 +350,43 @@ static void __init bootmem_free_node(int node, struct meminfo *mi) 
	free_area_init_node(node, zone_size, min, zhole_size);

}



#ifndef CONFIG_SPARSEMEM

int pfn_valid(unsigned long pfn)

{

	struct meminfo *mi = &meminfo;

	unsigned int left = 0, right = mi->nr_banks;



	do {

		unsigned int mid = (right + left) / 2;

		struct membank *bank = &mi->bank[mid];



		if (pfn < bank_pfn_start(bank))

			right = mid;

		else if (pfn >= bank_pfn_end(bank))

			left = mid + 1;

		else

			return 1;

	} while (left < right);

	return 0;

}

EXPORT_SYMBOL(pfn_valid);

#endif



static int __init meminfo_cmp(const void *_a, const void *_b)

{

	const struct membank *a = _a, *b = _b;

	long cmp = bank_pfn_start(a) - bank_pfn_start(b);

	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;

}



void __init bootmem_init(void)

{

	struct meminfo *mi = &meminfo;

	unsigned long min, max_low, max_high;

	int node, initrd_node;



	sort(&mi->bank, mi->nr_banks, sizeof(mi->bank[0]), meminfo_cmp, NULL);



	/*

	 * Locate which node contains the ramdisk image, if any.

	 */