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); 107