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[ARM] 3705/1: add supersection support to ioremap()

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Patch from Lennert Buytenhek

Analogous to the previous patch that allows ioremap() to use section
mappings, this patch allows ioremap() to use supersection mappings.
Original patch by Deepak Saxena.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Lennert Buytenhek 2006-07-01 19:58:20 +01:00 committed by Russell King
parent ae95bfbb2b
commit a069c896d0
2 changed files with 65 additions and 5 deletions
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66
arch/arm/mm/ioremap.c
View file

@ -33,8 +33,8 @@
#include <asm/sizes.h>
/*
* Used by ioremap() and iounmap() code to mark section-mapped I/O regions
* in vm_struct->flags field.
* Used by ioremap() and iounmap() code to mark (super)section-mapped
* I/O regions in vm_struct->flags field.
*/
#define VM_ARM_SECTION_MAPPING 0x80000000
@ -233,6 +233,54 @@ remap_area_sections(unsigned long virt, unsigned long pfn,
return 0;
}
static int
remap_area_supersections(unsigned long virt, unsigned long pfn,
unsigned long size, unsigned long flags)
{
unsigned long prot, addr = virt, end = virt + size;
pgd_t *pgd;
/*
* Remove and free any PTE-based mapping, and
* sync the current kernel mapping.
*/
unmap_area_sections(virt, size);
prot = PMD_TYPE_SECT | PMD_SECT_SUPER | PMD_SECT_AP_WRITE |
PMD_DOMAIN(DOMAIN_IO) |
(flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));
/*
* ARMv6 and above need XN set to prevent speculative prefetches
* hitting IO.
*/
if (cpu_architecture() >= CPU_ARCH_ARMv6)
prot |= PMD_SECT_XN;
pgd = pgd_offset_k(virt);
do {
unsigned long super_pmd_val, i;
super_pmd_val = __pfn_to_phys(pfn) | prot;
super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
for (i = 0; i < 8; i++) {
pmd_t *pmd = pmd_offset(pgd, addr);
pmd[0] = __pmd(super_pmd_val);
pmd[1] = __pmd(super_pmd_val);
flush_pmd_entry(pmd);
addr += PGDIR_SIZE;
pgd++;
}
pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
} while (addr < end);
return 0;
}
#endif
@ -255,6 +303,13 @@ __ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
int err;
unsigned long addr;
struct vm_struct * area;
unsigned int cr = get_cr();
/*
* High mappings must be supersection aligned
*/
if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
return NULL;
area = get_vm_area(size, VM_IOREMAP);
if (!area)
@ -262,7 +317,12 @@ __ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
addr = (unsigned long)area->addr;
#ifndef CONFIG_SMP
if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (cr & CR_XP)) ||
cpu_is_xsc3()) &&
!((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_supersections(addr, pfn, size, flags);
} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
area->flags |= VM_ARM_SECTION_MAPPING;
err = remap_area_sections(addr, pfn, size, flags);
} else

4
include/asm-arm/memory.h
View file

@ -69,9 +69,9 @@
#define XIP_VIRT_ADDR(physaddr) (MODULE_START + ((physaddr) & 0x000fffff))
/*
* Allow 2MB-aligned ioremap pages
* Allow 16MB-aligned ioremap pages
*/
#define IOREMAP_MAX_ORDER 21
#define IOREMAP_MAX_ORDER 24
#else /* CONFIG_MMU */