| 1 | /* |
| 2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/vmalloc.h> |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/io.h> |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/cache.h> |
| 16 | |
| 17 | static inline bool arc_uncached_addr_space(phys_addr_t paddr) |
| 18 | { |
| 19 | if (is_isa_arcompact()) { |
| 20 | if (paddr >= ARC_UNCACHED_ADDR_SPACE) |
| 21 | return true; |
| 22 | } else if (paddr >= perip_base && paddr <= perip_end) { |
| 23 | return true; |
| 24 | } |
| 25 | |
| 26 | return false; |
| 27 | } |
| 28 | |
| 29 | void __iomem *ioremap(phys_addr_t paddr, unsigned long size) |
| 30 | { |
| 31 | phys_addr_t end; |
| 32 | |
| 33 | /* Don't allow wraparound or zero size */ |
| 34 | end = paddr + size - 1; |
| 35 | if (!size || (end < paddr)) |
| 36 | return NULL; |
| 37 | |
| 38 | /* |
| 39 | * If the region is h/w uncached, MMU mapping can be elided as optim |
| 40 | * The cast to u32 is fine as this region can only be inside 4GB |
| 41 | */ |
| 42 | if (arc_uncached_addr_space(paddr)) |
| 43 | return (void __iomem *)(u32)paddr; |
| 44 | |
| 45 | return ioremap_prot(paddr, size, PAGE_KERNEL_NO_CACHE); |
| 46 | } |
| 47 | EXPORT_SYMBOL(ioremap); |
| 48 | |
| 49 | /* |
| 50 | * ioremap with access flags |
| 51 | * Cache semantics wise it is same as ioremap - "forced" uncached. |
| 52 | * However unlike vanilla ioremap which bypasses ARC MMU for addresses in |
| 53 | * ARC hardware uncached region, this one still goes thru the MMU as caller |
| 54 | * might need finer access control (R/W/X) |
| 55 | */ |
| 56 | void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size, |
| 57 | unsigned long flags) |
| 58 | { |
| 59 | unsigned long vaddr; |
| 60 | struct vm_struct *area; |
| 61 | phys_addr_t off, end; |
| 62 | pgprot_t prot = __pgprot(flags); |
| 63 | |
| 64 | /* Don't allow wraparound, zero size */ |
| 65 | end = paddr + size - 1; |
| 66 | if ((!size) || (end < paddr)) |
| 67 | return NULL; |
| 68 | |
| 69 | /* An early platform driver might end up here */ |
| 70 | if (!slab_is_available()) |
| 71 | return NULL; |
| 72 | |
| 73 | /* force uncached */ |
| 74 | prot = pgprot_noncached(prot); |
| 75 | |
| 76 | /* Mappings have to be page-aligned */ |
| 77 | off = paddr & ~PAGE_MASK; |
| 78 | paddr &= PAGE_MASK; |
| 79 | size = PAGE_ALIGN(end + 1) - paddr; |
| 80 | |
| 81 | /* |
| 82 | * Ok, go for it.. |
| 83 | */ |
| 84 | area = get_vm_area(size, VM_IOREMAP); |
| 85 | if (!area) |
| 86 | return NULL; |
| 87 | area->phys_addr = paddr; |
| 88 | vaddr = (unsigned long)area->addr; |
| 89 | if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) { |
| 90 | vunmap((void __force *)vaddr); |
| 91 | return NULL; |
| 92 | } |
| 93 | return (void __iomem *)(off + (char __iomem *)vaddr); |
| 94 | } |
| 95 | EXPORT_SYMBOL(ioremap_prot); |
| 96 | |
| 97 | |
| 98 | void iounmap(const void __iomem *addr) |
| 99 | { |
| 100 | /* weird double cast to handle phys_addr_t > 32 bits */ |
| 101 | if (arc_uncached_addr_space((phys_addr_t)(u32)addr)) |
| 102 | return; |
| 103 | |
| 104 | vfree((void *)(PAGE_MASK & (unsigned long __force)addr)); |
| 105 | } |
| 106 | EXPORT_SYMBOL(iounmap); |