1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P. 4 * Bjorn Helgaas <bjorn.helgaas@hp.com> 5 */ 6 7 #include <linux/compiler.h> 8 #include <linux/module.h> 9 #include <linux/efi.h> 10 #include <linux/io.h> 11 #include <linux/mm.h> 12 #include <linux/vmalloc.h> 13 #include <asm/io.h> 14 #include <asm/meminit.h> 15 16 static inline void __iomem * 17 __ioremap_uc(unsigned long phys_addr) 18 { 19 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); 20 } 21 22 void __iomem * 23 early_ioremap (unsigned long phys_addr, unsigned long size) 24 { 25 u64 attr; 26 attr = kern_mem_attribute(phys_addr, size); 27 if (attr & EFI_MEMORY_WB) 28 return (void __iomem *) phys_to_virt(phys_addr); 29 return __ioremap_uc(phys_addr); 30 } 31 32 void __iomem * 33 ioremap (unsigned long phys_addr, unsigned long size) 34 { 35 void __iomem *addr; 36 struct vm_struct *area; 37 unsigned long offset; 38 pgprot_t prot; 39 u64 attr; 40 unsigned long gran_base, gran_size; 41 unsigned long page_base; 42 43 /* 44 * For things in kern_memmap, we must use the same attribute 45 * as the rest of the kernel. For more details, see 46 * Documentation/ia64/aliasing.rst. 47 */ 48 attr = kern_mem_attribute(phys_addr, size); 49 if (attr & EFI_MEMORY_WB) 50 return (void __iomem *) phys_to_virt(phys_addr); 51 else if (attr & EFI_MEMORY_UC) 52 return __ioremap_uc(phys_addr); 53 54 /* 55 * Some chipsets don't support UC access to memory. If 56 * WB is supported for the whole granule, we prefer that. 57 */ 58 gran_base = GRANULEROUNDDOWN(phys_addr); 59 gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; 60 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) 61 return (void __iomem *) phys_to_virt(phys_addr); 62 63 /* 64 * WB is not supported for the whole granule, so we can't use 65 * the region 7 identity mapping. If we can safely cover the 66 * area with kernel page table mappings, we can use those 67 * instead. 68 */ 69 page_base = phys_addr & PAGE_MASK; 70 size = PAGE_ALIGN(phys_addr + size) - page_base; 71 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { 72 prot = PAGE_KERNEL; 73 74 /* 75 * Mappings have to be page-aligned 76 */ 77 offset = phys_addr & ~PAGE_MASK; 78 phys_addr &= PAGE_MASK; 79 80 /* 81 * Ok, go for it.. 82 */ 83 area = get_vm_area(size, VM_IOREMAP); 84 if (!area) 85 return NULL; 86 87 area->phys_addr = phys_addr; 88 addr = (void __iomem *) area->addr; 89 if (ioremap_page_range((unsigned long) addr, 90 (unsigned long) addr + size, phys_addr, prot)) { 91 vunmap((void __force *) addr); 92 return NULL; 93 } 94 95 return (void __iomem *) (offset + (char __iomem *)addr); 96 } 97 98 return __ioremap_uc(phys_addr); 99 } 100 EXPORT_SYMBOL(ioremap); 101 102 void __iomem * 103 ioremap_uc(unsigned long phys_addr, unsigned long size) 104 { 105 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) 106 return NULL; 107 108 return __ioremap_uc(phys_addr); 109 } 110 EXPORT_SYMBOL(ioremap_uc); 111 112 void 113 early_iounmap (volatile void __iomem *addr, unsigned long size) 114 { 115 } 116 117 void 118 iounmap (volatile void __iomem *addr) 119 { 120 if (REGION_NUMBER(addr) == RGN_GATE) 121 vunmap((void *) ((unsigned long) addr & PAGE_MASK)); 122 } 123 EXPORT_SYMBOL(iounmap); 124