Commit 9d4ae727 authored by Deepak Saxena's avatar Deepak Saxena Committed by Russell King
Browse files

[ARM] 3070/2: Add __ioremap_pfn() API 



Patch from Deepak Saxena

In working on adding 36-bit addressed supersection support to ioremap(),
I came to the conclusion that it would be far simpler to do so by just
splitting __ioremap() into a main external interface and adding an
__ioremap_pfn() function that takes a pfn + offset into the page that
__ioremap() can call. This way existing callers of __ioremap() won't have
to change their code and 36-bit systems will just call __ioremap_pfn()
and we will not have to deal with unsigned long long variables.

Note that __ioremap_pfn() should _NOT_ be called directly by drivers
but is reserved for use by arch_ioremap() implementations that map
32-bit resource regions into the real 36-bit address and then call
this new function.

Signed-off-by: default avatarDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 16ed926e

arch/arm/mm/ioremap.c

+29 −20
Original line number Diff line number Diff line
@@ -86,11 +86,12 @@ remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, 
}



static int

remap_area_pages(unsigned long start, unsigned long phys_addr,

remap_area_pages(unsigned long start, unsigned long pfn,

		 unsigned long size, unsigned long flags)

{

	unsigned long address = start;

	unsigned long end = start + size;

	unsigned long phys_addr = __pfn_to_phys(pfn);

	int err = 0;

	pgd_t * dir;
@@ -130,36 +131,44 @@ remap_area_pages(unsigned long start, unsigned long phys_addr, 
 * mapping.  See include/asm-arm/proc-armv/pgtable.h for more information.

 */

void __iomem *

__ioremap(unsigned long phys_addr, size_t size, unsigned long flags)

__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,

	      unsigned long flags)

{

	void * addr;

	unsigned long addr;

 	struct vm_struct * area;

	unsigned long offset, last_addr;



	/* Don't allow wraparound or zero size */

 	area = get_vm_area(size, VM_IOREMAP);

 	if (!area)

 		return NULL;

 	addr = (unsigned long)area->addr;

 	if (remap_area_pages(addr, pfn, size, flags)) {

 		vfree(addr);

 		return NULL;

 	}

 	return (void __iomem *) (offset + (char *)addr);

}

EXPORT_SYMBOL(__ioremap_pfn);



void __iomem *

__ioremap(unsigned long phys_addr, size_t size, unsigned long flags)

{

	unsigned long last_addr;

 	unsigned long offset = phys_addr & ~PAGE_MASK;

 	unsigned long pfn = __phys_to_pfn(phys_addr);



 	/*

 	 * Don't allow wraparound or zero size

	 */

	last_addr = phys_addr + size - 1;

	if (!size || last_addr < phys_addr)

		return NULL;



	/*

	 * Mappings have to be page-aligned

 	 * Page align the mapping size

	 */

	offset = phys_addr & ~PAGE_MASK;

	phys_addr &= PAGE_MASK;

	size = PAGE_ALIGN(last_addr + 1) - phys_addr;



	/*

	 * Ok, go for it..

	 */

	area = get_vm_area(size, VM_IOREMAP);

	if (!area)

		return NULL;

	addr = area->addr;

	if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {

		vfree(addr);

		return NULL;

	}

	return (void __iomem *) (offset + (char *)addr);

 	return __ioremap_pfn(pfn, offset, size, flags);

}

EXPORT_SYMBOL(__ioremap);

include/asm-arm/io.h

+6 −0
Original line number Diff line number Diff line
@@ -56,7 +56,12 @@ extern void __raw_readsl(const void __iomem *addr, void *data, int longlen); 


/*

 * Architecture ioremap implementation.

 *

 * __ioremap takes CPU physical address.

 *

 * __ioremap_pfn takes a Page Frame Number and an offset into that page

 */

extern void __iomem * __ioremap_pfn(unsigned long, unsigned long, size_t, unsigned long);

extern void __iomem * __ioremap(unsigned long, size_t, unsigned long);

extern void __iounmap(void __iomem *addr);
@@ -261,6 +266,7 @@ out: 
 *

 * ioremap takes a PCI memory address, as specified in

 * Documentation/IO-mapping.txt.

 *

 */

#ifndef __arch_ioremap

#define ioremap(cookie,size)		__ioremap(cookie,size,0)

include/asm-arm/mach/map.h

+0 −3
Original line number Diff line number Diff line
@@ -27,9 +27,6 @@ struct meminfo; 
#define MT_ROM			6

#define MT_IXP2000_DEVICE	7



#define	__phys_to_pfn(paddr)	((paddr) >> PAGE_SHIFT)

#define	__pfn_to_phys(pfn)	((pfn) << PAGE_SHIFT)



extern void create_memmap_holes(struct meminfo *);

extern void memtable_init(struct meminfo *);

extern void iotable_init(struct map_desc *, int);

include/asm-arm/memory.h

+6 −0
Original line number Diff line number Diff line
@@ -57,6 +57,12 @@ 
#define __phys_to_virt(x)	((x) - PHYS_OFFSET + PAGE_OFFSET)

#endif



/*

 * Convert a physical address to a Page Frame Number and back

 */

#define	__phys_to_pfn(paddr)	((paddr) >> PAGE_SHIFT)

#define	__pfn_to_phys(pfn)	((pfn) << PAGE_SHIFT)



/*

 * The module space lives between the addresses given by TASK_SIZE

 * and PAGE_OFFSET - it must be within 32MB of the kernel text.

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