/* * linux/arch/m32r/mm/ioremap.c * * Copyright (c) 2001, 2002 Hiroyuki Kondo * * Taken from mips version. * (C) Copyright 1995 1996 Linus Torvalds * (C) Copyright 2001 Ralf Baechle */ /* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * */ #include <linux/module.h> #include <asm/addrspace.h> #include <asm/byteorder.h> #include <linux/vmalloc.h> #include <asm/io.h> #include <asm/pgalloc.h> #include <asm/cacheflush.h> #include <asm/tlbflush.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; unsigned long pfn; pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | flags); address &= ~PMD_MASK; end = address + size; if (end > PMD_SIZE) end = PMD_SIZE; if (address >= end) BUG(); pfn = phys_addr >> PAGE_SHIFT; do { if (!pte_none(*pte)) { printk("remap_area_pte: page already exists\n"); BUG(); } 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; phys_addr -= address; if (address >= end) BUG(); do { pte_t * pte = pte_alloc_kernel(&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 error; } /* * 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. * * 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. */ #define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL)) void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) { void __iomem * addr; struct vm_struct * area; unsigned long offset, last_addr; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; if (!size || last_addr < phys_addr) return NULL; /* * Map objects in the low 512mb of address space using KSEG1, otherwise * map using page tables. */ if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1)) return (void *) KSEG1ADDR(phys_addr); /* * 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 + 1) - phys_addr; /* * Ok, go for it.. */ area = get_vm_area(size, VM_IOREMAP); if (!area) return NULL; area->phys_addr = phys_addr; addr = (void __iomem *) area->addr; if (remap_area_pages((unsigned long)addr, phys_addr, size, flags)) { vunmap((void __force *) addr); return NULL; } return (void __iomem *) (offset + (char __iomem *)addr); } #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1) void iounmap(volatile void __iomem *addr) { if (!IS_KSEG1(addr)) vfree((void *) (PAGE_MASK & (unsigned long) addr)); }