OpenCloudOS-Kernel/arch/arc/mm/ioremap.c

65 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*/
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/cache.h>
static inline bool arc_uncached_addr_space(phys_addr_t paddr)
{
if (is_isa_arcompact()) {
if (paddr >= ARC_UNCACHED_ADDR_SPACE)
return true;
} else if (paddr >= perip_base && paddr <= perip_end) {
return true;
}
return false;
}
void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
{
/*
* If the region is h/w uncached, MMU mapping can be elided as optim
* The cast to u32 is fine as this region can only be inside 4GB
*/
if (arc_uncached_addr_space(paddr))
return (void __iomem *)(u32)paddr;
return ioremap_prot(paddr, size,
pgprot_val(pgprot_noncached(PAGE_KERNEL)));
}
EXPORT_SYMBOL(ioremap);
/*
* ioremap with access flags
* Cache semantics wise it is same as ioremap - "forced" uncached.
* However unlike vanilla ioremap which bypasses ARC MMU for addresses in
* ARC hardware uncached region, this one still goes thru the MMU as caller
* might need finer access control (R/W/X)
*/
void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
unsigned long flags)
{
pgprot_t prot = __pgprot(flags);
/* force uncached */
return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
}
EXPORT_SYMBOL(ioremap_prot);
void iounmap(volatile void __iomem *addr)
{
/* weird double cast to handle phys_addr_t > 32 bits */
if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
return;
generic_iounmap(addr);
}
EXPORT_SYMBOL(iounmap);