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 (unsigned long phys_addr) 20 { 21 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); 22 } 23 24 void __iomem * 25 ioremap (unsigned long phys_addr, unsigned long size) 26 { 27 void __iomem *addr; 28 struct vm_struct *area; 29 unsigned long offset; 30 pgprot_t prot; 31 u64 attr; 32 unsigned long gran_base, gran_size; 33 unsigned long page_base; 34 35 /* 36 * For things in kern_memmap, we must use the same attribute 37 * as the rest of the kernel. For more details, see 38 * Documentation/ia64/aliasing.txt. 39 */ 40 attr = kern_mem_attribute(phys_addr, size); 41 if (attr & EFI_MEMORY_WB) 42 return (void __iomem *) phys_to_virt(phys_addr); 43 else if (attr & EFI_MEMORY_UC) 44 return __ioremap(phys_addr); 45 46 /* 47 * Some chipsets don't support UC access to memory. If 48 * WB is supported for the whole granule, we prefer that. 49 */ 50 gran_base = GRANULEROUNDDOWN(phys_addr); 51 gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; 52 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) 53 return (void __iomem *) phys_to_virt(phys_addr); 54 55 /* 56 * WB is not supported for the whole granule, so we can't use 57 * the region 7 identity mapping. If we can safely cover the 58 * area with kernel page table mappings, we can use those 59 * instead. 60 */ 61 page_base = phys_addr & PAGE_MASK; 62 size = PAGE_ALIGN(phys_addr + size) - page_base; 63 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { 64 prot = PAGE_KERNEL; 65 66 /* 67 * Mappings have to be page-aligned 68 */ 69 offset = phys_addr & ~PAGE_MASK; 70 phys_addr &= PAGE_MASK; 71 72 /* 73 * Ok, go for it.. 74 */ 75 area = get_vm_area(size, VM_IOREMAP); 76 if (!area) 77 return NULL; 78 79 area->phys_addr = phys_addr; 80 addr = (void __iomem *) area->addr; 81 if (ioremap_page_range((unsigned long) addr, 82 (unsigned long) addr + size, phys_addr, prot)) { 83 vunmap((void __force *) addr); 84 return NULL; 85 } 86 87 return (void __iomem *) (offset + (char __iomem *)addr); 88 } 89 90 return __ioremap(phys_addr); 91 } 92 EXPORT_SYMBOL(ioremap); 93 94 void __iomem * 95 ioremap_nocache (unsigned long phys_addr, unsigned long size) 96 { 97 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) 98 return NULL; 99 100 return __ioremap(phys_addr); 101 } 102 EXPORT_SYMBOL(ioremap_nocache); 103 104 void 105 iounmap (volatile void __iomem *addr) 106 { 107 if (REGION_NUMBER(addr) == RGN_GATE) 108 vunmap((void *) ((unsigned long) addr & PAGE_MASK)); 109 } 110 EXPORT_SYMBOL(iounmap); 111