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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* OpenRISC ioremap.c
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* Modifications for the OpenRISC architecture:
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
*/
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
#include <asm/bug.h>
#include <linux/sched.h>
#include <asm/tlbflush.h>
extern int mem_init_done;
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
* directly.
*
* NOTE! We need to allow non-page-aligned mappings too: we will obviously
* have to convert them into an offset in a page-aligned mapping, but the
* caller shouldn't need to know that small detail.
*/
void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
{
phys_addr_t p;
unsigned long v;
unsigned long offset, last_addr;
struct vm_struct *area = NULL;
/* Don't allow wraparound or zero size */
last_addr = addr + size - 1;
if (!size || last_addr < addr)
return NULL;
/*
* Mappings have to be page-aligned
*/
offset = addr & ~PAGE_MASK;
p = addr & PAGE_MASK;
size = PAGE_ALIGN(last_addr + 1) - p;
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
v = (unsigned long)area->addr;
if (ioremap_page_range(v, v + size, p,
__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
vfree(area->addr);
return NULL;
}
return (void __iomem *)(offset + (char *)v);
}
EXPORT_SYMBOL(ioremap);
void iounmap(volatile void __iomem *addr)
{
return vfree((void *)(PAGE_MASK & (unsigned long)addr));
}
EXPORT_SYMBOL(iounmap);
/**
* OK, this one's a bit tricky... ioremap can get called before memory is
* initialized (early serial console does this) and will want to alloc a page
* for its mapping. No userspace pages will ever get allocated before memory
* is initialized so this applies only to kernel pages. In the event that
* this is called before memory is initialized we allocate the page using
* the memblock infrastructure.
*/
pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm)
{
pte_t *pte;
if (likely(mem_init_done)) {
pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
} else {
pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
}
return pte;
}
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