diff options
Diffstat (limited to 'kernel/arch/x86/mm/iomap_32.c')
-rw-r--r-- | kernel/arch/x86/mm/iomap_32.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/kernel/arch/x86/mm/iomap_32.c b/kernel/arch/x86/mm/iomap_32.c new file mode 100644 index 000000000..b2ffa5c7d --- /dev/null +++ b/kernel/arch/x86/mm/iomap_32.c @@ -0,0 +1,132 @@ +/* + * Copyright © 2008 Ingo Molnar + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#include <asm/iomap.h> +#include <asm/pat.h> +#include <linux/module.h> +#include <linux/highmem.h> + +static int is_io_mapping_possible(resource_size_t base, unsigned long size) +{ +#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT) + /* There is no way to map greater than 1 << 32 address without PAE */ + if (base + size > 0x100000000ULL) + return 0; +#endif + return 1; +} + +int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot) +{ + enum page_cache_mode pcm = _PAGE_CACHE_MODE_WC; + int ret; + + if (!is_io_mapping_possible(base, size)) + return -EINVAL; + + ret = io_reserve_memtype(base, base + size, &pcm); + if (ret) + return ret; + + *prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm)); + return 0; +} +EXPORT_SYMBOL_GPL(iomap_create_wc); + +void iomap_free(resource_size_t base, unsigned long size) +{ + io_free_memtype(base, base + size); +} +EXPORT_SYMBOL_GPL(iomap_free); + +void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + unsigned long vaddr; + int idx, type; + + preempt_disable(); + pagefault_disable(); + + type = kmap_atomic_idx_push(); + idx = type + KM_TYPE_NR * smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + WARN_ON(!pte_none(*(kmap_pte - idx))); + +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = pte; +#endif + set_pte(kmap_pte - idx, pte); + arch_flush_lazy_mmu_mode(); + + return (void *)vaddr; +} + +/* + * Map 'pfn' using protections 'prot' + */ +void __iomem * +iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) +{ + /* + * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS. + * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the + * MTRR is UC or WC. UC_MINUS gets the real intention, of the + * user, which is "WC if the MTRR is WC, UC if you can't do that." + */ + if (!pat_enabled && pgprot_val(prot) == + (__PAGE_KERNEL | cachemode2protval(_PAGE_CACHE_MODE_WC))) + prot = __pgprot(__PAGE_KERNEL | + cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); + + return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot); +} +EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn); + +void +iounmap_atomic(void __iomem *kvaddr) +{ + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + + if (vaddr >= __fix_to_virt(FIX_KMAP_END) && + vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) { + int idx, type; + + type = kmap_atomic_idx(); + idx = type + KM_TYPE_NR * smp_processor_id(); + +#ifdef CONFIG_DEBUG_HIGHMEM + WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); +#endif + /* + * Force other mappings to Oops if they'll try to access this + * pte without first remap it. Keeping stale mappings around + * is a bad idea also, in case the page changes cacheability + * attributes or becomes a protected page in a hypervisor. + */ +#ifdef CONFIG_PREEMPT_RT_FULL + current->kmap_pte[type] = __pte(0); +#endif + kpte_clear_flush(kmap_pte-idx, vaddr); + kmap_atomic_idx_pop(); + } + + pagefault_enable(); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(iounmap_atomic); |