1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * (C) Copyright 1995 1996 Linus Torvalds 7 * (C) Copyright 2001, 2002 Ralf Baechle 8 */ 9 #include <linux/export.h> 10 #include <asm/addrspace.h> 11 #include <asm/byteorder.h> 12 #include <linux/ioport.h> 13 #include <linux/sched.h> 14 #include <linux/slab.h> 15 #include <linux/vmalloc.h> 16 #include <linux/mm_types.h> 17 #include <linux/io.h> 18 #include <asm/cacheflush.h> 19 #include <asm/tlbflush.h> 20 #include <ioremap.h> 21 22 #define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL)) 23 #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1) 24 25 static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages, 26 void *arg) 27 { 28 unsigned long i; 29 30 for (i = 0; i < nr_pages; i++) { 31 if (pfn_valid(start_pfn + i) && 32 !PageReserved(pfn_to_page(start_pfn + i))) 33 return 1; 34 } 35 36 return 0; 37 } 38 39 /* 40 * ioremap_prot - map bus memory into CPU space 41 * @phys_addr: bus address of the memory 42 * @size: size of the resource to map 43 * 44 * ioremap_prot gives the caller control over cache coherency attributes (CCA) 45 */ 46 void __iomem *ioremap_prot(phys_addr_t phys_addr, unsigned long size, 47 unsigned long prot_val) 48 { 49 unsigned long flags = prot_val & _CACHE_MASK; 50 unsigned long offset, pfn, last_pfn; 51 struct vm_struct *area; 52 phys_addr_t last_addr; 53 unsigned long vaddr; 54 void __iomem *cpu_addr; 55 56 cpu_addr = plat_ioremap(phys_addr, size, flags); 57 if (cpu_addr) 58 return cpu_addr; 59 60 phys_addr = fixup_bigphys_addr(phys_addr, size); 61 62 /* Don't allow wraparound or zero size */ 63 last_addr = phys_addr + size - 1; 64 if (!size || last_addr < phys_addr) 65 return NULL; 66 67 /* 68 * Map uncached objects in the low 512mb of address space using KSEG1, 69 * otherwise map using page tables. 70 */ 71 if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) && 72 flags == _CACHE_UNCACHED) 73 return (void __iomem *) CKSEG1ADDR(phys_addr); 74 75 /* Early remaps should use the unmapped regions til' VM is available */ 76 if (WARN_ON_ONCE(!slab_is_available())) 77 return NULL; 78 79 /* 80 * Don't allow anybody to remap RAM that may be allocated by the page 81 * allocator, since that could lead to races & data clobbering. 82 */ 83 pfn = PFN_DOWN(phys_addr); 84 last_pfn = PFN_DOWN(last_addr); 85 if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, 86 __ioremap_check_ram) == 1) { 87 WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", 88 &phys_addr, &last_addr); 89 return NULL; 90 } 91 92 /* 93 * Mappings have to be page-aligned 94 */ 95 offset = phys_addr & ~PAGE_MASK; 96 phys_addr &= PAGE_MASK; 97 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 98 99 /* 100 * Ok, go for it.. 101 */ 102 area = get_vm_area(size, VM_IOREMAP); 103 if (!area) 104 return NULL; 105 vaddr = (unsigned long)area->addr; 106 107 flags |= _PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | __WRITEABLE; 108 if (ioremap_page_range(vaddr, vaddr + size, phys_addr, 109 __pgprot(flags))) { 110 free_vm_area(area); 111 return NULL; 112 } 113 114 return (void __iomem *)(vaddr + offset); 115 } 116 EXPORT_SYMBOL(ioremap_prot); 117 118 void iounmap(const volatile void __iomem *addr) 119 { 120 if (!plat_iounmap(addr) && !IS_KSEG1(addr)) 121 vunmap((void *)((unsigned long)addr & PAGE_MASK)); 122 } 123 EXPORT_SYMBOL(iounmap); 124