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