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 2001-2006 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, unsigned long flags) 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 flags |= _PAGE_NO_CACHE; 42 } 43 #endif 44 45 /* Don't allow wraparound or zero size */ 46 last_addr = phys_addr + size - 1; 47 if (!size || last_addr < phys_addr) 48 return NULL; 49 50 /* 51 * Don't allow anybody to remap normal RAM that we're using.. 52 */ 53 if (phys_addr < virt_to_phys(high_memory)) { 54 char *t_addr, *t_end; 55 struct page *page; 56 57 t_addr = __va(phys_addr); 58 t_end = t_addr + (size - 1); 59 60 for (page = virt_to_page(t_addr); 61 page <= virt_to_page(t_end); page++) { 62 if(!PageReserved(page)) 63 return NULL; 64 } 65 } 66 67 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | 68 _PAGE_ACCESSED | flags); 69 70 /* 71 * Mappings have to be page-aligned 72 */ 73 offset = phys_addr & ~PAGE_MASK; 74 phys_addr &= PAGE_MASK; 75 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 76 77 /* 78 * Ok, go for it.. 79 */ 80 area = get_vm_area(size, VM_IOREMAP); 81 if (!area) 82 return NULL; 83 84 addr = (void __iomem *) area->addr; 85 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, 86 phys_addr, pgprot)) { 87 vfree(addr); 88 return NULL; 89 } 90 91 return (void __iomem *) (offset + (char __iomem *)addr); 92 } 93 EXPORT_SYMBOL(__ioremap); 94 95 void iounmap(const volatile void __iomem *addr) 96 { 97 if (addr > high_memory) 98 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr)); 99 } 100 EXPORT_SYMBOL(iounmap); 101