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
......@@ -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;
......@@ -129,37 +130,45 @@ remap_area_pages(unsigned long start, unsigned long phys_addr,
* 'flags' are the extra L_PTE_ flags that you want to specify for this
* mapping. See include/asm-arm/proc-armv/pgtable.h for more information.
*/
void __iomem *
__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
unsigned long flags)
{
unsigned long addr;
struct vm_struct * area;
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)
{
void * addr;
struct vm_struct * area;
unsigned long offset, last_addr;
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 */
/*
* 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);
......
......@@ -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)
......
......@@ -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);
......
......@@ -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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