1 // SPDX-License-Identifier: GPL-2.0
3 * Re-map IO memory to kernel address space so that we can access it.
4 * This is needed for high PCI addresses that aren't mapped in the
5 * 640k-1MB IO memory area on PC's
7 * (C) Copyright 1995 1996 Linus Torvalds
9 #include <linux/vmalloc.h>
11 #include <linux/sched.h>
13 #include <linux/export.h>
14 #include <asm/cacheflush.h>
16 #include "pgalloc-track.h"
18 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
19 static unsigned int __ro_after_init iomap_max_page_shift
= BITS_PER_LONG
- 1;
21 static int __init
set_nohugeiomap(char *str
)
23 iomap_max_page_shift
= PAGE_SHIFT
;
26 early_param("nohugeiomap", set_nohugeiomap
);
27 #else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
28 static const unsigned int iomap_max_page_shift
= PAGE_SHIFT
;
29 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
31 int ioremap_page_range(unsigned long addr
,
32 unsigned long end
, phys_addr_t phys_addr
, pgprot_t prot
)
34 return vmap_range(addr
, end
, phys_addr
, prot
, iomap_max_page_shift
);
37 #ifdef CONFIG_GENERIC_IOREMAP
38 void __iomem
*ioremap_prot(phys_addr_t addr
, size_t size
, unsigned long prot
)
40 unsigned long offset
, vaddr
;
41 phys_addr_t last_addr
;
42 struct vm_struct
*area
;
44 /* Disallow wrap-around or zero size */
45 last_addr
= addr
+ size
- 1;
46 if (!size
|| last_addr
< addr
)
49 /* Page-align mappings */
50 offset
= addr
& (~PAGE_MASK
);
52 size
= PAGE_ALIGN(size
+ offset
);
54 area
= get_vm_area_caller(size
, VM_IOREMAP
,
55 __builtin_return_address(0));
58 vaddr
= (unsigned long)area
->addr
;
60 if (ioremap_page_range(vaddr
, vaddr
+ size
, addr
, __pgprot(prot
))) {
65 return (void __iomem
*)(vaddr
+ offset
);
67 EXPORT_SYMBOL(ioremap_prot
);
69 void iounmap(volatile void __iomem
*addr
)
71 vunmap((void *)((unsigned long)addr
& PAGE_MASK
));
73 EXPORT_SYMBOL(iounmap
);
74 #endif /* CONFIG_GENERIC_IOREMAP */