patch-2.3.16 linux/include/asm-i386/bigmem.h

• Lines: 70
• Date: Tue Aug 31 16:12:02 1999
• Orig file: v2.3.15/linux/include/asm-i386/bigmem.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.15/linux/include/asm-i386/bigmem.h linux/include/asm-i386/bigmem.h
@@ -0,0 +1,69 @@
+/*
+ * bigmem.h:	virtual kernel memory mappings for big memory
+ *
+ * Used in CONFIG_BIGMEM systems for memory pages which	are not
+ * addressable by direct kernel virtual adresses.
+ *
+ * Copyright (C) 1999 Gerhard Wichert, Siemens AG
+ *		      Gerhard.Wichert@pdb.siemens.de
+ */
+
+#ifndef _ASM_BIGMEM_H
+#define _ASM_BIGMEM_H
+
+#include <linux/init.h>
+
+#define BIGMEM_DEBUG /* undef for production */
+
+/* declarations for bigmem.c */
+extern unsigned long bigmem_start, bigmem_end;
+extern int nr_free_bigpages;
+
+extern pte_t *kmap_pte;
+extern pgprot_t kmap_prot;
+
+extern void kmap_init(void) __init;
+
+/* kmap helper functions necessary to access the bigmem pages in kernel */
+#include <asm/pgtable.h>
+#include <asm/kmap_types.h>
+
+extern inline unsigned long kmap(unsigned long kaddr, enum km_type type)
+{
+	if (__pa(kaddr) < bigmem_start)
+		return kaddr;
+	{
+		enum fixed_addresses idx = type+KM_TYPE_NR*smp_processor_id();
+		unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN+idx);
+
+#ifdef BIGMEM_DEBUG
+		if (!pte_none(*(kmap_pte-idx)))
+		{
+			__label__ here;
+		here:
+			printk(KERN_ERR "not null pte on CPU %d from %p\n",
+			       smp_processor_id(), &&here);
+		}
+#endif
+		set_pte(kmap_pte-idx, mk_pte(kaddr & PAGE_MASK, kmap_prot));
+		__flush_tlb_one(vaddr);
+
+		return vaddr | (kaddr & ~PAGE_MASK);
+	}
+}
+
+extern inline void kunmap(unsigned long vaddr, enum km_type type)
+{
+#ifdef BIGMEM_DEBUG
+	enum fixed_addresses idx = type+KM_TYPE_NR*smp_processor_id();
+	if ((vaddr & PAGE_MASK) == __fix_to_virt(FIX_KMAP_BEGIN+idx))
+	{
+		/* 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 /* _ASM_BIGMEM_H */