WSL2-Linux-Kernel/arch/ia64/mm/ioremap.c

61 строка
1.6 KiB
C

/*
* (c) Copyright 2006 Hewlett-Packard Development Company, L.P.
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*
* 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.
*/
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <asm/io.h>
#include <asm/meminit.h>
static inline void __iomem *
__ioremap (unsigned long offset, unsigned long size)
{
return (void __iomem *) (__IA64_UNCACHED_OFFSET | offset);
}
void __iomem *
ioremap (unsigned long offset, unsigned long size)
{
u64 attr;
unsigned long gran_base, gran_size;
/*
* For things in kern_memmap, we must use the same attribute
* as the rest of the kernel. For more details, see
* Documentation/ia64/aliasing.txt.
*/
attr = kern_mem_attribute(offset, size);
if (attr & EFI_MEMORY_WB)
return (void __iomem *) phys_to_virt(offset);
else if (attr & EFI_MEMORY_UC)
return __ioremap(offset, size);
/*
* Some chipsets don't support UC access to memory. If
* WB is supported for the whole granule, we prefer that.
*/
gran_base = GRANULEROUNDDOWN(offset);
gran_size = GRANULEROUNDUP(offset + size) - gran_base;
if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
return (void __iomem *) phys_to_virt(offset);
return __ioremap(offset, size);
}
EXPORT_SYMBOL(ioremap);
void __iomem *
ioremap_nocache (unsigned long offset, unsigned long size)
{
if (kern_mem_attribute(offset, size) & EFI_MEMORY_WB)
return NULL;
return __ioremap(offset, size);
}
EXPORT_SYMBOL(ioremap_nocache);