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/*
* arch/arm/mm/attrib_alloc.c
*
* Page allocator with custom cache attributes
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/kernel.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/page-flags.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/outercache.h>
#include <asm/attrib_alloc.h>
#include "mm.h"
static void update_kmap_pte(struct page *page, pgprot_t prot)
{
#ifdef CONFIG_HIGHMEM
unsigned long addr;
pte_t *pte;
addr = (unsigned long)kmap_high_get(page);
BUG_ON(!PageHighMem(page) || addr >= FIXADDR_START);
if (!addr)
return;
pte = &pkmap_page_table[PKMAP_NR(addr)];
set_pte_at(&init_mm, addr, pte, mk_pte(page, __pgprot(prot)));
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
kunmap_high(page);
#endif
}
static void update_pte(struct page *page, pgprot_t prot)
{
#ifdef CONFIG_ARCH_LOWMEM_IN_PTES
unsigned long addr = (unsigned long)page_address(page);
pgd_t *pgd = pgd_offset_k(addr);
pmd_t *pmd = pmd_offset(pgd, addr);
pte_t *pte;
BUG_ON(pmd_none(*pmd));
pte = pte_offset_kernel(pmd, addr);
set_pte_at(&init_mm, addr, pte, mk_pte(page, __pgprot(prot)));
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
#endif
}
void arm_attrib_free_pages_exact(struct page *page, size_t size)
{
struct page *p, *e;
size = PAGE_ALIGN(size);
e = page + (size >> PAGE_SHIFT);
/* reset the page's mappings back to the standard kernel mappings
* before returning it to the page allocator */
for (p = page; p < e; p++) {
if (PageHighMem(p))
update_kmap_pte(p, pgprot_kernel);
else
update_pte(p, pgprot_kernel);
__free_page(p);
}
}
struct page *arm_attrib_alloc_pages_exact_node(int nid, gfp_t gfp,
size_t size, pgprot_t prot)
{
struct page *page, *p, *e;
unsigned int order;
unsigned long base;
size = PAGE_ALIGN(size);
order = get_order(size);
page = alloc_pages_node(nid, gfp, order);
if (!page)
return NULL;
split_page(page, order);
e = page + (1 << order);
for (p = page + (size >> PAGE_SHIFT); p < e; p++)
__free_page(p);
e = page + (size >> PAGE_SHIFT);
for (p = page; p < e; p++) {
__flush_dcache_page(page_mapping(p), p);
/* even though a freshly-allocated highmem page shouldn't
* be mapped, because the kmaps are flushed lazily, it
* is possible that a mapping from an old kmap_high call
* is still present, and its cache attributes need to
* be updated to match the new expectations */
if (PageHighMem(p))
update_kmap_pte(p, prot);
else
update_pte(p, prot);
}
base = page_to_phys(page);
outer_flush_range(base, base + size);
return page;
}
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