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linux-next/arch/arm64/mm/ioremap.c

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/*
* Based on arch/arm/mm/ioremap.c
*
* (C) Copyright 1995 1996 Linus Torvalds
* Hacked for ARM by Phil Blundell <philb@gnu.org>
* Hacked to allow all architectures to build, and various cleanups
* by Russell King
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
pgprot_t prot, void *caller)
{
unsigned long last_addr;
unsigned long offset = phys_addr & ~PAGE_MASK;
int err;
unsigned long addr;
struct vm_struct *area;
/*
* Page align the mapping address and size, taking account of any
* offset.
*/
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(size + offset);
/*
* Don't allow wraparound, zero size or outside PHYS_MASK.
*/
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
return NULL;
/*
* Don't allow RAM to be mapped.
*/
if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
return NULL;
area = get_vm_area_caller(size, VM_IOREMAP, caller);
if (!area)
return NULL;
addr = (unsigned long)area->addr;
err = ioremap_page_range(addr, addr + size, phys_addr, prot);
if (err) {
vunmap((void *)addr);
return NULL;
}
return (void __iomem *)(offset + addr);
}
void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
{
return __ioremap_caller(phys_addr, size, prot,
__builtin_return_address(0));
}
EXPORT_SYMBOL(__ioremap);
void __iounmap(volatile void __iomem *io_addr)
{
unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
/*
* We could get an address outside vmalloc range in case
* of ioremap_cache() reusing a RAM mapping.
*/
if (VMALLOC_START <= addr && addr < VMALLOC_END)
vunmap((void *)addr);
}
EXPORT_SYMBOL(__iounmap);
void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
{
/* For normal memory we already have a cacheable mapping. */
if (pfn_valid(__phys_to_pfn(phys_addr)))
return (void __iomem *)__phys_to_virt(phys_addr);
return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_cache);
#ifndef CONFIG_ARM64_64K_PAGES
static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
#endif
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pgd = pgd_offset_k(addr);
BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
pud = pud_offset(pgd, addr);
BUG_ON(pud_none(*pud) || pud_bad(*pud));
return pmd_offset(pud, addr);
}
static inline pte_t * __init early_ioremap_pte(unsigned long addr)
{
pmd_t *pmd = early_ioremap_pmd(addr);
BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd));
return pte_offset_kernel(pmd, addr);
}
void __init early_ioremap_init(void)
{
pmd_t *pmd;
pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
#ifndef CONFIG_ARM64_64K_PAGES
/* need to populate pmd for 4k pagesize only */
pmd_populate_kernel(&init_mm, pmd, bm_pte);
#endif
/*
* The boot-ioremap range spans multiple pmds, for which
* we are not prepared:
*/
BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
!= (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
WARN_ON(1);
pr_warn("pmd %p != %p\n",
pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
fix_to_virt(FIX_BTMAP_BEGIN));
pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
fix_to_virt(FIX_BTMAP_END));
pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
pr_warn("FIX_BTMAP_BEGIN: %d\n",
FIX_BTMAP_BEGIN);
}
early_ioremap_setup();
}
void __init __early_set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
unsigned long addr = __fix_to_virt(idx);
pte_t *pte;
if (idx >= __end_of_fixed_addresses) {
BUG();
return;
}
pte = early_ioremap_pte(addr);
if (pgprot_val(flags))
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
else {
pte_clear(&init_mm, addr, pte);
flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
}
}