/* * This file contains ioremap and related functions for 64-bit machines. * * Derived from arch/ppc64/mm/init.c * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@samba.org) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * Dave Engebretsen * Rework for PPC64 port. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mmu_decl.h" unsigned long ioremap_bot = IOREMAP_BASE; /* * map_io_page currently only called by __ioremap * map_io_page adds an entry to the ioremap page table * and adds an entry to the HPT, possibly bolting it */ static int map_io_page(unsigned long ea, unsigned long pa, int flags) { pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp; pte_t *ptep; if (mem_init_done) { pgdp = pgd_offset_k(ea); pudp = pud_alloc(&init_mm, pgdp, ea); if (!pudp) return -ENOMEM; pmdp = pmd_alloc(&init_mm, pudp, ea); if (!pmdp) return -ENOMEM; ptep = pte_alloc_kernel(pmdp, ea); if (!ptep) return -ENOMEM; set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); } else { /* * If the mm subsystem is not fully up, we cannot create a * linux page table entry for this mapping. Simply bolt an * entry in the hardware page table. * */ if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags, mmu_io_psize, mmu_kernel_ssize)) { printk(KERN_ERR "Failed to do bolted mapping IO " "memory at %016lx !\n", pa); return -ENOMEM; } } return 0; } /** * __ioremap_at - Low level function to establish the page tables * for an IO mapping */ void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size, unsigned long flags) { unsigned long i; /* Make sure we have the base flags */ if ((flags & _PAGE_PRESENT) == 0) flags |= pgprot_val(PAGE_KERNEL); /* Non-cacheable page cannot be coherent */ if (flags & _PAGE_NO_CACHE) flags &= ~_PAGE_COHERENT; /* We don't support the 4K PFN hack with ioremap */ if (flags & _PAGE_4K_PFN) return NULL; WARN_ON(pa & ~PAGE_MASK); WARN_ON(((unsigned long)ea) & ~PAGE_MASK); WARN_ON(size & ~PAGE_MASK); for (i = 0; i < size; i += PAGE_SIZE) if (map_io_page((unsigned long)ea+i, pa+i, flags)) return NULL; return (void __iomem *)ea; } /** * __iounmap_from - Low level function to tear down the page tables * for an IO mapping. This is used for mappings that * are manipulated manually, like partial unmapping of * PCI IOs or ISA space. */ void __iounmap_at(void *ea, unsigned long size) { WARN_ON(((unsigned long)ea) & ~PAGE_MASK); WARN_ON(size & ~PAGE_MASK); unmap_kernel_range((unsigned long)ea, size); } void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, void *caller) { phys_addr_t paligned; void __iomem *ret; /* * Choose an address to map it to. * Once the imalloc system is running, we use it. * Before that, we map using addresses going * up from ioremap_bot. imalloc will use * the addresses from ioremap_bot through * IMALLOC_END * */ paligned = addr & PAGE_MASK; size = PAGE_ALIGN(addr + size) - paligned; if ((size == 0) || (paligned == 0)) return NULL; if (mem_init_done) { struct vm_struct *area; area = __get_vm_area_caller(size, VM_IOREMAP, ioremap_bot, IOREMAP_END, caller); if (area == NULL) return NULL; ret = __ioremap_at(paligned, area->addr, size, flags); if (!ret) vunmap(area->addr); } else { ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags); if (ret) ioremap_bot += size; } if (ret) ret += addr & ~PAGE_MASK; return ret; } void __iomem * __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) { return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); } void __iomem * ioremap(phys_addr_t addr, unsigned long size) { unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED; void *caller = __builtin_return_address(0); if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags, caller); return __ioremap_caller(addr, size, flags, caller); } void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) { void *caller = __builtin_return_address(0); /* writeable implies dirty for kernel addresses */ if (flags & _PAGE_RW) flags |= _PAGE_DIRTY; /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ flags &= ~(_PAGE_USER | _PAGE_EXEC); if (ppc_md.ioremap) return ppc_md.ioremap(addr, size, flags, caller); return __ioremap_caller(addr, size, flags, caller); } /* * Unmap an IO region and remove it from imalloc'd list. * Access to IO memory should be serialized by driver. */ void __iounmap(volatile void __iomem *token) { void *addr; if (!mem_init_done) return; addr = (void *) ((unsigned long __force) PCI_FIX_ADDR(token) & PAGE_MASK); if ((unsigned long)addr < ioremap_bot) { printk(KERN_WARNING "Attempt to iounmap early bolted mapping" " at 0x%p\n", addr); return; } vunmap(addr); } void iounmap(volatile void __iomem *token) { if (ppc_md.iounmap) ppc_md.iounmap(token); else __iounmap(token); } EXPORT_SYMBOL(ioremap); EXPORT_SYMBOL(ioremap_flags); EXPORT_SYMBOL(__ioremap); EXPORT_SYMBOL(__ioremap_at); EXPORT_SYMBOL(iounmap); EXPORT_SYMBOL(__iounmap); EXPORT_SYMBOL(__iounmap_at);