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 *ioremap_prot(phys_addr_t phys_addr, size_t size, 33 unsigned long flags) 34 { 35 u64 attr; 36 unsigned long gran_base, gran_size; 37 unsigned long page_base; 38 39 /* 40 * For things in kern_memmap, we must use the same attribute 41 * as the rest of the kernel. For more details, see 42 * Documentation/arch/ia64/aliasing.rst. 43 */ 44 attr = kern_mem_attribute(phys_addr, size); 45 if (attr & EFI_MEMORY_WB) 46 return (void __iomem *) phys_to_virt(phys_addr); 47 else if (attr & EFI_MEMORY_UC) 48 return __ioremap_uc(phys_addr); 49 50 /* 51 * Some chipsets don't support UC access to memory. If 52 * WB is supported for the whole granule, we prefer that. 53 */ 54 gran_base = GRANULEROUNDDOWN(phys_addr); 55 gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; 56 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) 57 return (void __iomem *) phys_to_virt(phys_addr); 58 59 /* 60 * WB is not supported for the whole granule, so we can't use 61 * the region 7 identity mapping. If we can safely cover the 62 * area with kernel page table mappings, we can use those 63 * instead. 64 */ 65 page_base = phys_addr & PAGE_MASK; 66 size = PAGE_ALIGN(phys_addr + size) - page_base; 67 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) 68 return generic_ioremap_prot(phys_addr, size, __pgprot(flags)); 69 70 return __ioremap_uc(phys_addr); 71 } 72 EXPORT_SYMBOL(ioremap_prot); 73 74 void __iomem * 75 ioremap_uc(unsigned long phys_addr, unsigned long size) 76 { 77 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) 78 return NULL; 79 80 return __ioremap_uc(phys_addr); 81 } 82 EXPORT_SYMBOL(ioremap_uc); 83 84 void 85 early_iounmap (volatile void __iomem *addr, unsigned long size) 86 { 87 } 88 89 void iounmap(volatile void __iomem *addr) 90 { 91 if (REGION_NUMBER(addr) == RGN_GATE) 92 vunmap((void *) ((unsigned long) addr & PAGE_MASK)); 93 } 94 EXPORT_SYMBOL(iounmap); 95