1 /* 2 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P. 3 * Bjorn Helgaas <bjorn.helgaas@hp.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 10 #include <linux/compiler.h> 11 #include <linux/module.h> 12 #include <linux/efi.h> 13 #include <linux/io.h> 14 #include <linux/vmalloc.h> 15 #include <asm/io.h> 16 #include <asm/meminit.h> 17 18 static inline void __iomem * 19 __ioremap_uc(unsigned long phys_addr) 20 { 21 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); 22 } 23 24 void __iomem * 25 early_ioremap (unsigned long phys_addr, unsigned long size) 26 { 27 u64 attr; 28 attr = kern_mem_attribute(phys_addr, size); 29 if (attr & EFI_MEMORY_WB) 30 return (void __iomem *) phys_to_virt(phys_addr); 31 return __ioremap_uc(phys_addr); 32 } 33 34 void __iomem * 35 ioremap (unsigned long phys_addr, unsigned long size) 36 { 37 void __iomem *addr; 38 struct vm_struct *area; 39 unsigned long offset; 40 pgprot_t prot; 41 u64 attr; 42 unsigned long gran_base, gran_size; 43 unsigned long page_base; 44 45 /* 46 * For things in kern_memmap, we must use the same attribute 47 * as the rest of the kernel. For more details, see 48 * Documentation/ia64/aliasing.txt. 49 */ 50 attr = kern_mem_attribute(phys_addr, size); 51 if (attr & EFI_MEMORY_WB) 52 return (void __iomem *) phys_to_virt(phys_addr); 53 else if (attr & EFI_MEMORY_UC) 54 return __ioremap_uc(phys_addr); 55 56 /* 57 * Some chipsets don't support UC access to memory. If 58 * WB is supported for the whole granule, we prefer that. 59 */ 60 gran_base = GRANULEROUNDDOWN(phys_addr); 61 gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; 62 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) 63 return (void __iomem *) phys_to_virt(phys_addr); 64 65 /* 66 * WB is not supported for the whole granule, so we can't use 67 * the region 7 identity mapping. If we can safely cover the 68 * area with kernel page table mappings, we can use those 69 * instead. 70 */ 71 page_base = phys_addr & PAGE_MASK; 72 size = PAGE_ALIGN(phys_addr + size) - page_base; 73 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { 74 prot = PAGE_KERNEL; 75 76 /* 77 * Mappings have to be page-aligned 78 */ 79 offset = phys_addr & ~PAGE_MASK; 80 phys_addr &= PAGE_MASK; 81 82 /* 83 * Ok, go for it.. 84 */ 85 area = get_vm_area(size, VM_IOREMAP); 86 if (!area) 87 return NULL; 88 89 area->phys_addr = phys_addr; 90 addr = (void __iomem *) area->addr; 91 if (ioremap_page_range((unsigned long) addr, 92 (unsigned long) addr + size, phys_addr, prot)) { 93 vunmap((void __force *) addr); 94 return NULL; 95 } 96 97 return (void __iomem *) (offset + (char __iomem *)addr); 98 } 99 100 return __ioremap_uc(phys_addr); 101 } 102 EXPORT_SYMBOL(ioremap); 103 104 void __iomem * 105 ioremap_nocache (unsigned long phys_addr, unsigned long size) 106 { 107 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) 108 return NULL; 109 110 return __ioremap_uc(phys_addr); 111 } 112 EXPORT_SYMBOL(ioremap_nocache); 113 114 void 115 early_iounmap (volatile void __iomem *addr, unsigned long size) 116 { 117 } 118 119 void 120 iounmap (volatile void __iomem *addr) 121 { 122 if (REGION_NUMBER(addr) == RGN_GATE) 123 vunmap((void *) ((unsigned long) addr & PAGE_MASK)); 124 } 125 EXPORT_SYMBOL(iounmap); 126