diff options
Diffstat (limited to 'kernel/arch/ia64/mm/ioremap.c')
-rw-r--r-- | kernel/arch/ia64/mm/ioremap.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/kernel/arch/ia64/mm/ioremap.c b/kernel/arch/ia64/mm/ioremap.c new file mode 100644 index 000000000..43964cde6 --- /dev/null +++ b/kernel/arch/ia64/mm/ioremap.c @@ -0,0 +1,125 @@ +/* + * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P. + * Bjorn Helgaas <bjorn.helgaas@hp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/compiler.h> +#include <linux/module.h> +#include <linux/efi.h> +#include <linux/io.h> +#include <linux/vmalloc.h> +#include <asm/io.h> +#include <asm/meminit.h> + +static inline void __iomem * +__ioremap_uc(unsigned long phys_addr) +{ + return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); +} + +void __iomem * +early_ioremap (unsigned long phys_addr, unsigned long size) +{ + u64 attr; + attr = kern_mem_attribute(phys_addr, size); + if (attr & EFI_MEMORY_WB) + return (void __iomem *) phys_to_virt(phys_addr); + return __ioremap_uc(phys_addr); +} + +void __iomem * +ioremap (unsigned long phys_addr, unsigned long size) +{ + void __iomem *addr; + struct vm_struct *area; + unsigned long offset; + pgprot_t prot; + u64 attr; + unsigned long gran_base, gran_size; + unsigned long page_base; + + /* + * For things in kern_memmap, we must use the same attribute + * as the rest of the kernel. For more details, see + * Documentation/ia64/aliasing.txt. + */ + attr = kern_mem_attribute(phys_addr, size); + if (attr & EFI_MEMORY_WB) + return (void __iomem *) phys_to_virt(phys_addr); + else if (attr & EFI_MEMORY_UC) + return __ioremap_uc(phys_addr); + + /* + * Some chipsets don't support UC access to memory. If + * WB is supported for the whole granule, we prefer that. + */ + gran_base = GRANULEROUNDDOWN(phys_addr); + gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; + if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) + return (void __iomem *) phys_to_virt(phys_addr); + + /* + * WB is not supported for the whole granule, so we can't use + * the region 7 identity mapping. If we can safely cover the + * area with kernel page table mappings, we can use those + * instead. + */ + page_base = phys_addr & PAGE_MASK; + size = PAGE_ALIGN(phys_addr + size) - page_base; + if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { + prot = PAGE_KERNEL; + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + + /* + * 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 (ioremap_page_range((unsigned long) addr, + (unsigned long) addr + size, phys_addr, prot)) { + vunmap((void __force *) addr); + return NULL; + } + + return (void __iomem *) (offset + (char __iomem *)addr); + } + + return __ioremap_uc(phys_addr); +} +EXPORT_SYMBOL(ioremap); + +void __iomem * +ioremap_nocache (unsigned long phys_addr, unsigned long size) +{ + if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) + return NULL; + + return __ioremap_uc(phys_addr); +} +EXPORT_SYMBOL(ioremap_nocache); + +void +early_iounmap (volatile void __iomem *addr, unsigned long size) +{ +} + +void +iounmap (volatile void __iomem *addr) +{ + if (REGION_NUMBER(addr) == RGN_GATE) + vunmap((void *) ((unsigned long) addr & PAGE_MASK)); +} +EXPORT_SYMBOL(iounmap); |