nios2: I/O Mapping
This patch adds several definitions for I/O accessors and ioremap(). Signed-off-by: Ley Foon Tan <lftan@altera.com>
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Ley Foon Tan
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6b8baec4d6
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/*
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* Copyright (C) 2014 Altera Corporation
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* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
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* Copyright (C) 2004 Microtronix Datacom Ltd.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#ifndef _ASM_NIOS2_IO_H
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#define _ASM_NIOS2_IO_H
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#include <asm/pgtable-bits.h>
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#include <asm-generic/iomap.h>
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/* PCI is not supported in nios2, set this to 0. */
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#define IO_SPACE_LIMIT 0
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#define readb_relaxed(addr) readb(addr)
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#define readw_relaxed(addr) readw(addr)
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#define readl_relaxed(addr) readl(addr)
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#define writeb_relaxed(x, addr) writeb(x, addr)
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#define writew_relaxed(x, addr) writew(x, addr)
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#define writel_relaxed(x, addr) writel(x, addr)
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#include <asm-generic/io.h>
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extern void __iomem *__ioremap(unsigned long physaddr, unsigned long size,
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unsigned long cacheflag);
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extern void __iounmap(void __iomem *addr);
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static inline void __iomem *ioremap(unsigned long physaddr, unsigned long size)
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{
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return __ioremap(physaddr, size, 0);
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}
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static inline void __iomem *ioremap_nocache(unsigned long physaddr,
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unsigned long size)
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{
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return __ioremap(physaddr, size, 0);
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}
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static inline void iounmap(void __iomem *addr)
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{
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__iounmap(addr);
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}
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/* Pages to physical address... */
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# define page_to_phys(page) virt_to_phys(page_to_virt(page))
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# define page_to_bus(page) page_to_virt(page)
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/* Macros used for converting between virtual and physical mappings. */
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# define phys_to_virt(vaddr) \
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((void *)((unsigned long)(vaddr) | CONFIG_NIOS2_KERNEL_REGION_BASE))
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/* Clear top 3 bits */
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# define virt_to_phys(vaddr) \
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((unsigned long)((unsigned long)(vaddr) & ~0xE0000000))
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#endif /* _ASM_NIOS2_IO_H */
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@ -0,0 +1,187 @@
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/*
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* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
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* Copyright (C) 2009 Wind River Systems Inc
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* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
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* Copyright (C) 2004 Microtronix Datacom Ltd.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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static inline void remap_area_pte(pte_t *pte, unsigned long address,
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unsigned long size, unsigned long phys_addr,
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unsigned long flags)
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{
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unsigned long end;
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unsigned long pfn;
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pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ
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| _PAGE_WRITE | flags);
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address &= ~PMD_MASK;
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end = address + size;
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if (end > PMD_SIZE)
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end = PMD_SIZE;
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if (address >= end)
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BUG();
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pfn = PFN_DOWN(phys_addr);
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do {
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if (!pte_none(*pte)) {
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pr_err("remap_area_pte: page already exists\n");
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BUG();
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}
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set_pte(pte, pfn_pte(pfn, pgprot));
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address += PAGE_SIZE;
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pfn++;
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pte++;
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} while (address && (address < end));
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}
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static inline int remap_area_pmd(pmd_t *pmd, unsigned long address,
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unsigned long size, unsigned long phys_addr,
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unsigned long flags)
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{
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unsigned long end;
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address &= ~PGDIR_MASK;
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end = address + size;
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if (end > PGDIR_SIZE)
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end = PGDIR_SIZE;
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phys_addr -= address;
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if (address >= end)
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BUG();
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do {
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pte_t *pte = pte_alloc_kernel(pmd, address);
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if (!pte)
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return -ENOMEM;
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remap_area_pte(pte, address, end - address, address + phys_addr,
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flags);
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address = (address + PMD_SIZE) & PMD_MASK;
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pmd++;
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} while (address && (address < end));
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return 0;
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}
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static int remap_area_pages(unsigned long address, unsigned long phys_addr,
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unsigned long size, unsigned long flags)
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{
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int error;
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pgd_t *dir;
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unsigned long end = address + size;
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phys_addr -= address;
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dir = pgd_offset(&init_mm, address);
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flush_cache_all();
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if (address >= end)
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BUG();
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do {
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pud_t *pud;
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pmd_t *pmd;
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error = -ENOMEM;
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pud = pud_alloc(&init_mm, dir, address);
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if (!pud)
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break;
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pmd = pmd_alloc(&init_mm, pud, address);
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if (!pmd)
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break;
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if (remap_area_pmd(pmd, address, end - address,
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phys_addr + address, flags))
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break;
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error = 0;
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address = (address + PGDIR_SIZE) & PGDIR_MASK;
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dir++;
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} while (address && (address < end));
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flush_tlb_all();
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return error;
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}
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#define IS_MAPPABLE_UNCACHEABLE(addr) (addr < 0x20000000UL)
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/*
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* Map some physical address range into the kernel address space.
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*/
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void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
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unsigned long cacheflag)
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{
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struct vm_struct *area;
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unsigned long offset;
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unsigned long last_addr;
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void *addr;
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/* Don't allow wraparound or zero size */
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr)
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return NULL;
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/* Don't allow anybody to remap normal RAM that we're using */
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if (phys_addr > PHYS_OFFSET && phys_addr < virt_to_phys(high_memory)) {
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char *t_addr, *t_end;
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struct page *page;
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t_addr = __va(phys_addr);
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t_end = t_addr + (size - 1);
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for (page = virt_to_page(t_addr);
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page <= virt_to_page(t_end); page++)
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if (!PageReserved(page))
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return NULL;
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}
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/*
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* Map uncached objects in the low part of address space to
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* CONFIG_NIOS2_IO_REGION_BASE
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*/
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if (IS_MAPPABLE_UNCACHEABLE(phys_addr) &&
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IS_MAPPABLE_UNCACHEABLE(last_addr) &&
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!(cacheflag & _PAGE_CACHED))
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return (void __iomem *)(CONFIG_NIOS2_IO_REGION_BASE + phys_addr);
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/* Mappings have to be page-aligned */
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offset = phys_addr & ~PAGE_MASK;
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phys_addr &= PAGE_MASK;
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size = PAGE_ALIGN(last_addr + 1) - phys_addr;
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/* Ok, go for it */
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area = get_vm_area(size, VM_IOREMAP);
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if (!area)
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return NULL;
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addr = area->addr;
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if (remap_area_pages((unsigned long) addr, phys_addr, size,
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cacheflag)) {
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vunmap(addr);
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return NULL;
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}
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return (void __iomem *) (offset + (char *)addr);
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}
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EXPORT_SYMBOL(__ioremap);
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/*
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* __iounmap unmaps nearly everything, so be careful
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* it doesn't free currently pointer/page tables anymore but it
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* wasn't used anyway and might be added later.
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*/
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void __iounmap(void __iomem *addr)
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{
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struct vm_struct *p;
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if ((unsigned long) addr > CONFIG_NIOS2_IO_REGION_BASE)
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return;
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p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr));
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if (!p)
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pr_err("iounmap: bad address %p\n", addr);
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kfree(p);
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}
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EXPORT_SYMBOL(__iounmap);
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