diff options
| -rw-r--r-- | arch/arm/include/asm/highmem.h | 28 | ||||
| -rw-r--r-- | arch/arm/include/asm/memory.h | 13 | ||||
| -rw-r--r-- | arch/arm/mm/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mm/flush.c | 2 | ||||
| -rw-r--r-- | arch/arm/mm/highmem.c | 116 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 13 |
6 files changed, 169 insertions, 4 deletions
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h new file mode 100644 index 00000000000..023d5b37454 --- /dev/null +++ b/arch/arm/include/asm/highmem.h @@ -0,0 +1,28 @@ +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#include <asm/kmap_types.h> + +#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE) +#define LAST_PKMAP PTRS_PER_PTE +#define LAST_PKMAP_MASK (LAST_PKMAP - 1) +#define PKMAP_NR(virt) (((virt) - PKMAP_BASE) >> PAGE_SHIFT) +#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) + +#define kmap_prot PAGE_KERNEL + +#define flush_cache_kmaps() flush_cache_all() + +extern pte_t *pkmap_page_table; + +extern void *kmap_high(struct page *page); +extern void kunmap_high(struct page *page); + +extern void *kmap(struct page *page); +extern void kunmap(struct page *page); +extern void *kmap_atomic(struct page *page, enum km_type type); +extern void kunmap_atomic(void *kvaddr, enum km_type type); +extern void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); +extern struct page *kmap_atomic_to_page(const void *ptr); + +#endif diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 0202a7c20e6..ae472bc376d 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -44,14 +44,21 @@ * The module space lives between the addresses given by TASK_SIZE * and PAGE_OFFSET - it must be within 32MB of the kernel text. */ -#define MODULES_END (PAGE_OFFSET) -#define MODULES_VADDR (MODULES_END - 16*1048576) - +#define MODULES_VADDR (PAGE_OFFSET - 16*1024*1024) #if TASK_SIZE > MODULES_VADDR #error Top of user space clashes with start of module space #endif /* + * The highmem pkmap virtual space shares the end of the module area. + */ +#ifdef CONFIG_HIGHMEM +#define MODULES_END (PAGE_OFFSET - PMD_SIZE) +#else +#define MODULES_END (PAGE_OFFSET) +#endif + +/* * The XIP kernel gets mapped at the bottom of the module vm area. * Since we use sections to map it, this macro replaces the physical address * with its virtual address while keeping offset from the base section. diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 480f78a3611..185e7dc7dcf 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_MODULES) += proc-syms.o obj-$(CONFIG_ALIGNMENT_TRAP) += alignment.o obj-$(CONFIG_DISCONTIGMEM) += discontig.o +obj-$(CONFIG_HIGHMEM) += highmem.o obj-$(CONFIG_CPU_ABRT_NOMMU) += abort-nommu.o obj-$(CONFIG_CPU_ABRT_EV4) += abort-ev4.o diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 0fa9bf388f0..4e283481cee 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -192,7 +192,7 @@ void flush_dcache_page(struct page *page) struct address_space *mapping = page_mapping(page); #ifndef CONFIG_SMP - if (mapping && !mapping_mapped(mapping)) + if (!PageHighMem(page) && mapping && !mapping_mapped(mapping)) set_bit(PG_dcache_dirty, &page->flags); else #endif diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c new file mode 100644 index 00000000000..a34954d9df7 --- /dev/null +++ b/arch/arm/mm/highmem.c @@ -0,0 +1,116 @@ +/* + * arch/arm/mm/highmem.c -- ARM highmem support + * + * Author: Nicolas Pitre + * Created: september 8, 2008 + * Copyright: Marvell Semiconductors Inc. + * + * 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/module.h> +#include <linux/highmem.h> +#include <linux/interrupt.h> +#include <asm/fixmap.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include "mm.h" + +void *kmap(struct page *page) +{ + might_sleep(); + if (!PageHighMem(page)) + return page_address(page); + return kmap_high(page); +} +EXPORT_SYMBOL(kmap); + +void kunmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return; + kunmap_high(page); +} +EXPORT_SYMBOL(kunmap); + +void *kmap_atomic(struct page *page, enum km_type type) +{ + unsigned int idx; + unsigned long vaddr; + + pagefault_disable(); + if (!PageHighMem(page)) + return page_address(page); + + idx = type + KM_TYPE_NR * smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); +#ifdef CONFIG_DEBUG_HIGHMEM + /* + * With debugging enabled, kunmap_atomic forces that entry to 0. + * Make sure it was indeed properly unmapped. + */ + BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); +#endif + set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0); + /* + * When debugging is off, kunmap_atomic leaves the previous mapping + * in place, so this TLB flush ensures the TLB is updated with the + * new mapping. + */ + local_flush_tlb_kernel_page(vaddr); + + return (void *)vaddr; +} +EXPORT_SYMBOL(kmap_atomic); + +void kunmap_atomic(void *kvaddr, enum km_type type) +{ + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + unsigned int idx = type + KM_TYPE_NR * smp_processor_id(); + + if (kvaddr >= (void *)FIXADDR_START) { + __cpuc_flush_dcache_page((void *)vaddr); +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + set_pte_ext(TOP_PTE(vaddr), __pte(0), 0); + local_flush_tlb_kernel_page(vaddr); +#else + (void) idx; /* to kill a warning */ +#endif + } + pagefault_enable(); +} +EXPORT_SYMBOL(kunmap_atomic); + +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +{ + unsigned int idx; + unsigned long vaddr; + + pagefault_disable(); + + idx = type + KM_TYPE_NR * smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(!pte_none(*(TOP_PTE(vaddr)))); +#endif + set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0); + local_flush_tlb_kernel_page(vaddr); + + return (void *)vaddr; +} + +struct page *kmap_atomic_to_page(const void *ptr) +{ + unsigned long vaddr = (unsigned long)ptr; + pte_t *pte; + + if (vaddr < FIXADDR_START) + return virt_to_page(ptr); + + pte = TOP_PTE(vaddr); + return pte_page(*pte); +} diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index d4d082c5c2d..4810a4c9ffc 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -21,6 +21,7 @@ #include <asm/setup.h> #include <asm/sizes.h> #include <asm/tlb.h> +#include <asm/highmem.h> #include <asm/mach/arch.h> #include <asm/mach/map.h> @@ -895,6 +896,17 @@ static void __init devicemaps_init(struct machine_desc *mdesc) flush_cache_all(); } +static void __init kmap_init(void) +{ +#ifdef CONFIG_HIGHMEM + pmd_t *pmd = pmd_off_k(PKMAP_BASE); + pte_t *pte = alloc_bootmem_low_pages(2 * PTRS_PER_PTE * sizeof(pte_t)); + BUG_ON(!pmd_none(*pmd) || !pte); + __pmd_populate(pmd, __pa(pte) | _PAGE_KERNEL_TABLE); + pkmap_page_table = pte + PTRS_PER_PTE; +#endif +} + /* * paging_init() sets up the page tables, initialises the zone memory * maps, and sets up the zero page, bad page and bad page tables. @@ -908,6 +920,7 @@ void __init paging_init(struct machine_desc *mdesc) prepare_page_table(); bootmem_init(); devicemaps_init(mdesc); + kmap_init(); top_pmd = pmd_off_k(0xffff0000); |