From fd9409343521eac22b6ed51686128a643c7c976b Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 30 Oct 2008 19:37:09 -0700 Subject: x86: add iomap_atomic*()/iounmap_atomic() on 32-bit using fixmaps Impact: introduce new APIs, separate kmap code from CONFIG_HIGHMEM This takes the code used for CONFIG_HIGHMEM memory mappings except that it's designed for dynamic IO resource mapping. These fixmaps are available even with CONFIG_HIGHMEM turned off. Signed-off-by: Keith Packard Signed-off-by: Eric Anholt Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fixmap.h | 4 +++ arch/x86/include/asm/fixmap_32.h | 4 --- arch/x86/include/asm/highmem.h | 5 +--- arch/x86/mm/Makefile | 2 +- arch/x86/mm/init_32.c | 3 +- arch/x86/mm/iomap_32.c | 59 ++++++++++++++++++++++++++++++++++++++++ 6 files changed, 66 insertions(+), 11 deletions(-) create mode 100644 arch/x86/mm/iomap_32.c (limited to 'arch') diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index 8668a94f850e..23696d44a0af 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -9,6 +9,10 @@ extern int fixmaps_set; +extern pte_t *kmap_pte; +extern pgprot_t kmap_prot; +extern pte_t *pkmap_page_table; + void __native_set_fixmap(enum fixed_addresses idx, pte_t pte); void native_set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags); diff --git a/arch/x86/include/asm/fixmap_32.h b/arch/x86/include/asm/fixmap_32.h index 09f29ab5c139..c7115c1d7217 100644 --- a/arch/x86/include/asm/fixmap_32.h +++ b/arch/x86/include/asm/fixmap_32.h @@ -28,10 +28,8 @@ extern unsigned long __FIXADDR_TOP; #include #include #include -#ifdef CONFIG_HIGHMEM #include #include -#endif /* * Here we define all the compile-time 'special' virtual @@ -75,10 +73,8 @@ enum fixed_addresses { #ifdef CONFIG_X86_CYCLONE_TIMER FIX_CYCLONE_TIMER, /*cyclone timer register*/ #endif -#ifdef CONFIG_HIGHMEM FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, -#endif #ifdef CONFIG_PCI_MMCONFIG FIX_PCIE_MCFG, #endif diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h index a3b3b7c3027b..bf9276bea660 100644 --- a/arch/x86/include/asm/highmem.h +++ b/arch/x86/include/asm/highmem.h @@ -25,14 +25,11 @@ #include #include #include +#include /* declarations for highmem.c */ extern unsigned long highstart_pfn, highend_pfn; -extern pte_t *kmap_pte; -extern pgprot_t kmap_prot; -extern pte_t *pkmap_page_table; - /* * Right now we initialize only a single pte table. It can be extended * easily, subsequent pte tables have to be allocated in one physical diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 59f89b434b45..fea4565ff576 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -1,7 +1,7 @@ obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \ pat.o pgtable.o gup.o -obj-$(CONFIG_X86_32) += pgtable_32.o +obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_X86_PTDUMP) += dump_pagetables.o diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 8396868e82c5..c483f4242079 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -334,7 +334,6 @@ int devmem_is_allowed(unsigned long pagenr) return 0; } -#ifdef CONFIG_HIGHMEM pte_t *kmap_pte; pgprot_t kmap_prot; @@ -357,6 +356,7 @@ static void __init kmap_init(void) kmap_prot = PAGE_KERNEL; } +#ifdef CONFIG_HIGHMEM static void __init permanent_kmaps_init(pgd_t *pgd_base) { unsigned long vaddr; @@ -436,7 +436,6 @@ static void __init set_highmem_pages_init(void) #endif /* !CONFIG_NUMA */ #else -# define kmap_init() do { } while (0) # define permanent_kmaps_init(pgd_base) do { } while (0) # define set_highmem_pages_init() do { } while (0) #endif /* CONFIG_HIGHMEM */ diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c new file mode 100644 index 000000000000..d0151d8ce452 --- /dev/null +++ b/arch/x86/mm/iomap_32.c @@ -0,0 +1,59 @@ +/* + * 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 +#include + +/* Map 'pfn' using fixed map 'type' and protections 'prot' + */ +void * +iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + pagefault_disable(); + + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(kmap_pte-idx, pfn_pte(pfn, prot)); + arch_flush_lazy_mmu_mode(); + + return (void*) vaddr; +} +EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn); + +void +iounmap_atomic(void *kvaddr, enum km_type type) +{ + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); + + /* + * 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. + */ + if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) + kpte_clear_flush(kmap_pte-idx, vaddr); + + arch_flush_lazy_mmu_mode(); + pagefault_enable(); +} +EXPORT_SYMBOL_GPL(iounmap_atomic); -- cgit v1.2.2