| /* |
| * arch/s390/mm/ioremap.c |
| * |
| * S390 version |
| * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| * Author(s): Hartmut Penner (hp@de.ibm.com) |
| * |
| * Derived from "arch/i386/mm/extable.c" |
| * (C) Copyright 1995 1996 Linus Torvalds |
| * |
| * 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 |
| */ |
| |
| #include <linux/vmalloc.h> |
| #include <asm/io.h> |
| #include <asm/pgalloc.h> |
| |
| static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size, |
| unsigned long phys_addr, unsigned long flags) |
| { |
| unsigned long end; |
| |
| address &= ~PMD_MASK; |
| end = address + size; |
| if (end > PMD_SIZE) |
| end = PMD_SIZE; |
| if (address >= end) |
| BUG(); |
| do { |
| if (!pte_none(*pte)) { |
| printk("remap_area_pte: page already exists\n"); |
| BUG(); |
| } |
| set_pte(pte, mk_pte_phys(phys_addr, |
| __pgprot(_PAGE_PRESENT | flags))); |
| address += PAGE_SIZE; |
| phys_addr += PAGE_SIZE; |
| pte++; |
| } while (address && (address < end)); |
| } |
| |
| static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, |
| unsigned long phys_addr, unsigned long flags) |
| { |
| unsigned long end; |
| |
| address &= ~PGDIR_MASK; |
| end = address + size; |
| if (end > PGDIR_SIZE) |
| end = PGDIR_SIZE; |
| phys_addr -= address; |
| if (address >= end) |
| BUG(); |
| do { |
| pte_t * pte = pte_alloc(&init_mm, pmd, address); |
| if (!pte) |
| return -ENOMEM; |
| remap_area_pte(pte, address, end - address, address + phys_addr, flags); |
| address = (address + PMD_SIZE) & PMD_MASK; |
| pmd++; |
| } while (address && (address < end)); |
| return 0; |
| } |
| |
| static int remap_area_pages(unsigned long address, unsigned long phys_addr, |
| unsigned long size, unsigned long flags) |
| { |
| int error; |
| pgd_t * dir; |
| unsigned long end = address + size; |
| |
| phys_addr -= address; |
| dir = pgd_offset(&init_mm, address); |
| flush_cache_all(); |
| if (address >= end) |
| BUG(); |
| spin_lock(&init_mm.page_table_lock); |
| do { |
| pmd_t *pmd; |
| pmd = pmd_alloc(&init_mm, dir, address); |
| error = -ENOMEM; |
| if (!pmd) |
| break; |
| if (remap_area_pmd(pmd, address, end - address, |
| phys_addr + address, flags)) |
| break; |
| error = 0; |
| address = (address + PGDIR_SIZE) & PGDIR_MASK; |
| dir++; |
| } while (address && (address < end)); |
| spin_unlock(&init_mm.page_table_lock); |
| flush_tlb_all(); |
| return 0; |
| } |
| |
| /* |
| * Generic mapping function (not visible outside): |
| */ |
| |
| /* |
| * Remap an arbitrary physical address space into the kernel virtual |
| * address space. Needed when the kernel wants to access high addresses |
| * directly. |
| */ |
| void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) |
| { |
| void * addr; |
| struct vm_struct * area; |
| |
| if (phys_addr < virt_to_phys(high_memory)) |
| return phys_to_virt(phys_addr); |
| if (phys_addr & ~PAGE_MASK) |
| return NULL; |
| size = PAGE_ALIGN(size); |
| if (!size || size > phys_addr + size) |
| return NULL; |
| area = get_vm_area(size, VM_IOREMAP); |
| if (!area) |
| return NULL; |
| addr = area->addr; |
| if (remap_area_pages(VMALLOC_VMADDR(addr), phys_addr, size, flags)) { |
| vfree(addr); |
| return NULL; |
| } |
| return addr; |
| } |
| |
| void iounmap(void *addr) |
| { |
| if (addr > high_memory) |
| return vfree(addr); |
| } |