diff options
Diffstat (limited to 'arch/sh/mm/ioremap.c')
| -rw-r--r-- | arch/sh/mm/ioremap.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c new file mode 100644 index 000000000..213425811 --- /dev/null +++ b/arch/sh/mm/ioremap.c @@ -0,0 +1,192 @@ +/* + * arch/sh/mm/ioremap.c + * + * (C) Copyright 1995 1996 Linus Torvalds + * (C) Copyright 2005 - 2010 Paul Mundt + * + * 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 + * + * 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/vmalloc.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/pci.h> +#include <linux/io.h> +#include <asm/io_trapped.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/addrspace.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/mmu.h> +#include "ioremap.h" + +/* + * On 32-bit SH, we traditionally have the whole physical address space mapped + * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do + * anything but place the address in the proper segment. This is true for P1 + * and P2 addresses, as well as some P3 ones. However, most of the P3 addresses + * and newer cores using extended addressing need to map through page tables, so + * the ioremap() implementation becomes a bit more complicated. + */ +#ifdef CONFIG_29BIT +static void __iomem * +__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot) +{ + phys_addr_t last_addr = offset + size - 1; + + /* + * For P1 and P2 space this is trivial, as everything is already + * mapped. Uncached access for P1 addresses are done through P2. + * In the P3 case or for addresses outside of the 29-bit space, + * mapping must be done by the PMB or by using page tables. + */ + if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) { + u64 flags = pgprot_val(prot); + + /* + * Anything using the legacy PTEA space attributes needs + * to be kicked down to page table mappings. + */ + if (unlikely(flags & _PAGE_PCC_MASK)) + return NULL; + if (unlikely(flags & _PAGE_CACHABLE)) + return (void __iomem *)P1SEGADDR(offset); + + return (void __iomem *)P2SEGADDR(offset); + } + + /* P4 above the store queues are always mapped. */ + if (unlikely(offset >= P3_ADDR_MAX)) + return (void __iomem *)P4SEGADDR(offset); + + return NULL; +} +#else +#define __ioremap_29bit(offset, size, prot) NULL +#endif /* CONFIG_29BIT */ + +/* + * 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. + */ +void __iomem * __ref +__ioremap_caller(phys_addr_t phys_addr, unsigned long size, + pgprot_t pgprot, void *caller) +{ + struct vm_struct *area; + unsigned long offset, last_addr, addr, orig_addr; + void __iomem *mapped; + + mapped = __ioremap_trapped(phys_addr, size); + if (mapped) + return mapped; + + mapped = __ioremap_29bit(phys_addr, size, pgprot); + if (mapped) + return mapped; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + /* + * If we can't yet use the regular approach, go the fixmap route. + */ + if (!mem_init_done) + return ioremap_fixed(phys_addr, size, pgprot); + + /* + * First try to remap through the PMB. + * PMB entries are all pre-faulted. + */ + mapped = pmb_remap_caller(phys_addr, size, pgprot, caller); + if (mapped && !IS_ERR(mapped)) + return mapped; + + /* + * 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_caller(size, VM_IOREMAP, caller); + if (!area) + return NULL; + area->phys_addr = phys_addr; + orig_addr = addr = (unsigned long)area->addr; + + if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) { + vunmap((void *)orig_addr); + return NULL; + } + + return (void __iomem *)(offset + (char *)orig_addr); +} +EXPORT_SYMBOL(__ioremap_caller); + +/* + * Simple checks for non-translatable mappings. + */ +static inline int iomapping_nontranslatable(unsigned long offset) +{ +#ifdef CONFIG_29BIT + /* + * In 29-bit mode this includes the fixed P1/P2 areas, as well as + * parts of P3. + */ + if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX) + return 1; +#endif + + return 0; +} + +void iounmap(void __iomem *addr) +{ + unsigned long vaddr = (unsigned long __force)addr; + struct vm_struct *p; + + /* + * Nothing to do if there is no translatable mapping. + */ + if (iomapping_nontranslatable(vaddr)) + return; + + /* + * There's no VMA if it's from an early fixed mapping. + */ + if (iounmap_fixed(addr) == 0) + return; + + /* + * If the PMB handled it, there's nothing else to do. + */ + if (pmb_unmap(addr) == 0) + return; + + p = remove_vm_area((void *)(vaddr & PAGE_MASK)); + if (!p) { + printk(KERN_ERR "%s: bad address %p\n", __func__, addr); + return; + } + + kfree(p); +} +EXPORT_SYMBOL(iounmap); |