1 files changed, 132 insertions, 0 deletions
diff --git a/linux-2.4.26-xen-sparse/include/asm-xen/highmem.h b/linux-2.4.26-xen-sparse/include/asm-xen/highmem.h
new file mode 100644
index 0000000000..25ef32882c
--- /dev/null
+++ b/linux-2.4.26-xen-sparse/include/asm-xen/highmem.h
@@ -0,0 +1,132 @@
+/*
+ * highmem.h: virtual kernel memory mappings for high memory
+ *
+ * Used in CONFIG_HIGHMEM systems for memory pages which
+ * are not addressable by direct kernel virtual addresses.
+ *
+ * Copyright (C) 1999 Gerhard Wichert, Siemens AG
+ *		      Gerhard.Wichert@pdb.siemens.de
+ *
+ *
+ * Redesigned the x86 32-bit VM architecture to deal with 
+ * up to 16 Terabyte physical memory. With current x86 CPUs
+ * we now support up to 64 Gigabytes physical RAM.
+ *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+#ifndef _ASM_HIGHMEM_H
+#define _ASM_HIGHMEM_H
+
+#ifdef __KERNEL__
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <asm/kmap_types.h>
+#include <asm/pgtable.h>
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+#define HIGHMEM_DEBUG 1
+#else
+#define HIGHMEM_DEBUG 0
+#endif
+
+/* 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 kmap_init(void) __init;
+
+/*
+ * 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 (HYPERVISOR_VIRT_START - (1<<23))
+#ifdef CONFIG_X86_PAE
+#define LAST_PKMAP 512
+#else
+#define LAST_PKMAP 1024
+#endif
+#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 void * FASTCALL(kmap_high(struct page *page, int nonblocking));
+extern void FASTCALL(kunmap_high(struct page *page));
+
+#define kmap(page) __kmap(page, 0)
+#define kmap_nonblock(page) __kmap(page, 1)
+
+static inline void *__kmap(struct page *page, int nonblocking)
+{
+	if (in_interrupt())
+		out_of_line_bug();
+	if (page < highmem_start_page)
+		return page_address(page);
+	return kmap_high(page, nonblocking);
+}
+
+static inline void kunmap(struct page *page)
+{
+	if (in_interrupt())
+		out_of_line_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 void *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);
+
+	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)))
+		out_of_line_bug();
+#endif
+	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+	__flush_tlb_one(vaddr);
+
+	return (void*) vaddr;
+}
+
+static inline void kunmap_atomic(void *kvaddr, enum km_type type)
+{
+#if HIGHMEM_DEBUG
+	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+	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))
+		out_of_line_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 */