// SPDX-License-Identifier: GPL-2.0 /* * Re-map IO memory to kernel address space so that we can access it. * This is needed for high PCI addresses that aren't mapped in the * 640k-1MB IO memory area on PC's * * (C) Copyright 1995 1996 Linus Torvalds */ #include <linux/vmalloc.h> #include <linux/mm.h> #include <linux/io.h> #include <linux/export.h> void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot) { unsigned long offset, vaddr; phys_addr_t last_addr; struct vm_struct *area; /* Disallow wrap-around or zero size */ last_addr = addr + size - 1; if (!size || last_addr < addr) return NULL; /* Page-align mappings */ offset = addr & (~PAGE_MASK); addr -= offset; size = PAGE_ALIGN(size + offset); area = get_vm_area_caller(size, VM_IOREMAP, __builtin_return_address(0)); if (!area) return NULL; vaddr = (unsigned long)area->addr; if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) { free_vm_area(area); return NULL; } return (void __iomem *)(vaddr + offset); } EXPORT_SYMBOL(ioremap_prot); void iounmap(volatile void __iomem *addr) { vunmap((void *)((unsigned long)addr & PAGE_MASK)); } EXPORT_SYMBOL(iounmap);