---

yaml
---
r: 137432
b: refs/heads/master
c: d73cd42
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5f0fbf9ecaf354fa4bbf266fffdea2ea3d14a0ed
+refs/heads/master: d73cd42893f4cdc06e6829fea2347bb92cb789d1

trunk/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

trunk/arch/arm/include/asm/memory.h

@@ -44,13 +44,20 @@
  * 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

trunk/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

trunk/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

trunk/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);
+}

trunk/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);