1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch/parisc/mm/ioremap.c 4 * 5 * (C) Copyright 1995 1996 Linus Torvalds 6 * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de> 7 * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org> 8 */ 9 10 #include <linux/vmalloc.h> 11 #include <linux/errno.h> 12 #include <linux/module.h> 13 #include <linux/io.h> 14 #include <asm/pgalloc.h> 15 16 /* 17 * Generic mapping function (not visible outside): 18 */ 19 20 /* 21 * Remap an arbitrary physical address space into the kernel virtual 22 * address space. 23 * 24 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 25 * have to convert them into an offset in a page-aligned mapping, but the 26 * caller shouldn't need to know that small detail. 27 */ 28 void __iomem *ioremap(unsigned long phys_addr, unsigned long size) 29 { 30 void __iomem *addr; 31 struct vm_struct *area; 32 unsigned long offset, last_addr; 33 pgprot_t pgprot; 34 35 #ifdef CONFIG_EISA 36 unsigned long end = phys_addr + size - 1; 37 /* Support EISA addresses */ 38 if ((phys_addr >= 0x00080000 && end < 0x000fffff) || 39 (phys_addr >= 0x00500000 && end < 0x03bfffff)) 40 phys_addr |= F_EXTEND(0xfc000000); 41 #endif 42 43 /* Don't allow wraparound or zero size */ 44 last_addr = phys_addr + size - 1; 45 if (!size || last_addr < phys_addr) 46 return NULL; 47 48 /* 49 * Don't allow anybody to remap normal RAM that we're using.. 50 */ 51 if (phys_addr < virt_to_phys(high_memory)) { 52 char *t_addr, *t_end; 53 struct page *page; 54 55 t_addr = __va(phys_addr); 56 t_end = t_addr + (size - 1); 57 58 for (page = virt_to_page(t_addr); 59 page <= virt_to_page(t_end); page++) { 60 if(!PageReserved(page)) 61 return NULL; 62 } 63 } 64 65 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | 66 _PAGE_ACCESSED | _PAGE_NO_CACHE); 67 68 /* 69 * Mappings have to be page-aligned 70 */ 71 offset = phys_addr & ~PAGE_MASK; 72 phys_addr &= PAGE_MASK; 73 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 74 75 /* 76 * Ok, go for it.. 77 */ 78 area = get_vm_area(size, VM_IOREMAP); 79 if (!area) 80 return NULL; 81 82 addr = (void __iomem *) area->addr; 83 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, 84 phys_addr, pgprot)) { 85 vunmap(addr); 86 return NULL; 87 } 88 89 return (void __iomem *) (offset + (char __iomem *)addr); 90 } 91 EXPORT_SYMBOL(ioremap); 92 93 void iounmap(const volatile void __iomem *io_addr) 94 { 95 unsigned long addr = (unsigned long)io_addr & PAGE_MASK; 96 97 if (is_vmalloc_addr((void *)addr)) 98 vunmap((void *)addr); 99 } 100 EXPORT_SYMBOL(iounmap); 101