aboutsummaryrefslogtreecommitdiff
path: root/arch/mn10300/include/asm/highmem.h
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2009-04-10 14:19:03 +0100
committerDavid Howells <dhowells@redhat.com>2009-04-10 14:19:03 +0100
commitda7616610c8d2ec16a8ada44216e836e5fcbd08b (patch)
treeef3e8ccc7a01694c0ab0eeea387bc46a8807669e /arch/mn10300/include/asm/highmem.h
parent62b8e680e61d3f48f2a12ee248ca03ea8f376926 (diff)
downloadlinux-da7616610c8d2ec16a8ada44216e836e5fcbd08b.tar.gz
Move arch headers from include/asm-mn10300/ to arch/mn10300/include/asm/.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'arch/mn10300/include/asm/highmem.h')
-rw-r--r--arch/mn10300/include/asm/highmem.h116
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/highmem.h b/arch/mn10300/include/asm/highmem.h
new file mode 100644
index 000000000000..90f2abb04bfd
--- /dev/null
+++ b/arch/mn10300/include/asm/highmem.h
@@ -0,0 +1,116 @@
+/* MN10300 Virtual kernel memory mappings for high memory
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from include/asm-i386/highmem.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_HIGHMEM_H
+#define _ASM_HIGHMEM_H
+
+#ifdef __KERNEL__
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <asm/kmap_types.h>
+#include <asm/pgtable.h>
+
+/* undef for production */
+#undef HIGHMEM_DEBUG
+
+/* 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;
+
+extern void __init kmap_init(void);
+
+/*
+ * Right now we initialize only a single pte table. It can be extended
+ * easily, subsequent pte tables have to be allocated in one physical
+ * chunk of RAM.
+ */
+#define PKMAP_BASE 0xfe000000UL
+#define LAST_PKMAP 1024
+#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))
+
+extern unsigned long kmap_high(struct page *page);
+extern void kunmap_high(struct page *page);
+
+static inline unsigned long kmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (page < highmem_start_page)
+ return page_address(page);
+ return kmap_high(page);
+}
+
+static inline void kunmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (page < highmem_start_page)
+ return;
+ kunmap_high(page);
+}
+
+/*
+ * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
+ * gives a more generic (and caching) interface. But kmap_atomic can
+ * be used in IRQ contexts, so in some (very limited) cases we need
+ * it.
+ */
+static inline unsigned long kmap_atomic(struct page *page, enum km_type type)
+{
+ enum fixed_addresses idx;
+ unsigned long vaddr;
+
+ if (page < highmem_start_page)
+ return page_address(page);
+
+ debug_kmap_atomic(type);
+ idx = type + KM_TYPE_NR * smp_processor_id();
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+#if HIGHMEM_DEBUG
+ if (!pte_none(*(kmap_pte - idx)))
+ BUG();
+#endif
+ set_pte(kmap_pte - idx, mk_pte(page, kmap_prot));
+ __flush_tlb_one(vaddr);
+
+ return vaddr;
+}
+
+static inline void kunmap_atomic(unsigned long vaddr, enum km_type type)
+{
+#if HIGHMEM_DEBUG
+ enum fixed_addresses idx = type + KM_TYPE_NR * smp_processor_id();
+
+ if (vaddr < FIXADDR_START) /* FIXME */
+ return;
+
+ if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx))
+ BUG();
+
+ /*
+ * force other mappings to Oops if they'll try to access
+ * this pte without first remap it
+ */
+ pte_clear(kmap_pte - idx);
+ __flush_tlb_one(vaddr);
+#endif
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_HIGHMEM_H */