/* * arch/parisc/mm/ioremap.c * * (C) Copyright 1995 1996 Linus Torvalds * (C) Copyright 2001-2006 Helge Deller <deller@gmx.de> * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org> */ #include <linux/vmalloc.h> #include <linux/errno.h> #include <linux/module.h> #include <asm/io.h> #include <asm/pgalloc.h> #include <asm/tlbflush.h> #include <asm/cacheflush.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, pfn; pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | flags); address &= ~PMD_MASK; end = address + size; if (end > PMD_SIZE) end = PMD_SIZE; BUG_ON(address >= end); pfn = phys_addr >> PAGE_SHIFT; do { BUG_ON(!pte_none(*pte)); set_pte(pte, pfn_pte(pfn, pgprot)); address += PAGE_SIZE; pfn++; 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; BUG_ON(address >= end); phys_addr -= address; do { pte_t *pte = pte_alloc_kernel(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) { pgd_t *dir; int error = 0; unsigned long end = address + size; BUG_ON(address >= end); phys_addr -= address; dir = pgd_offset_k(address); flush_cache_all(); do { pud_t *pud; pmd_t *pmd; error = -ENOMEM; pud = pud_alloc(&init_mm, dir, address); if (!pud) break; pmd = pmd_alloc(&init_mm, pud, address); 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)); flush_tlb_all(); return error; } /* * Generic mapping function (not visible outside): */ /* * Remap an arbitrary physical address space into the kernel virtual * address space. * * NOTE! We need to allow non-page-aligned mappings too: we will obviously * have to convert them into an offset in a page-aligned mapping, but the * caller shouldn't need to know that small detail. */ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) { void *addr; struct vm_struct *area; unsigned long offset, last_addr; #ifdef CONFIG_EISA unsigned long end = phys_addr + size - 1; /* Support EISA addresses */ if ((phys_addr >= 0x00080000 && end < 0x000fffff) || (phys_addr >= 0x00500000 && end < 0x03bfffff)) { phys_addr |= F_EXTEND(0xfc000000); flags |= _PAGE_NO_CACHE; } #endif /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; if (!size || last_addr < phys_addr) return NULL; /* * Don't allow anybody to remap normal RAM that we're using.. */ if (phys_addr < virt_to_phys(high_memory)) { char *t_addr, *t_end; struct page *page; t_addr = __va(phys_addr); t_end = t_addr + (size - 1); for (page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++) { if(!PageReserved(page)) return NULL; } } /* * Mappings have to be page-aligned */ offset = phys_addr & ~PAGE_MASK; phys_addr &= PAGE_MASK; size = PAGE_ALIGN(last_addr) - phys_addr; /* * Ok, go for it.. */ area = get_vm_area(size, VM_IOREMAP); if (!area) return NULL; addr = area->addr; if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { vfree(addr); return NULL; } return (void __iomem *) (offset + (char *)addr); } EXPORT_SYMBOL(__ioremap); void iounmap(void __iomem *addr) { if (addr > high_memory) return vfree((void *) (PAGE_MASK & (unsigned long __force) addr)); } EXPORT_SYMBOL(iounmap);