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-rw-r--r--arch/arm/include/asm/highmem.h28
-rw-r--r--arch/arm/include/asm/memory.h13
-rw-r--r--arch/arm/mm/Makefile1
-rw-r--r--arch/arm/mm/flush.c2
-rw-r--r--arch/arm/mm/highmem.c116
-rw-r--r--arch/arm/mm/mmu.c13
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);