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authorRalf Baechle <ralf@linux-mips.org>2000-08-08 18:54:49 +0000
committerRalf Baechle <ralf@linux-mips.org>2000-08-08 18:54:49 +0000
commit5514f4babeeb3af00ee0c325e3cda7a562cc3d65 (patch)
treeedd733879cab73e41324a99ca5da7bc154c4196d /include/asm-sparc/highmem.h
parent6a9366db547e958e8c9bf8e1c13bcea6cb2bf393 (diff)
Merge with Linux 2.4.0-test6-pre4.
Diffstat (limited to 'include/asm-sparc/highmem.h')
-rw-r--r--include/asm-sparc/highmem.h149
1 files changed, 149 insertions, 0 deletions
diff --git a/include/asm-sparc/highmem.h b/include/asm-sparc/highmem.h
new file mode 100644
index 000000000..ede2167e1
--- /dev/null
+++ b/include/asm-sparc/highmem.h
@@ -0,0 +1,149 @@
+/*
+ * 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 adresses.
+ *
+ * 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 Terrabyte 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/vaddrs.h>
+#include <asm/kmap_types.h>
+#include <asm/pgtable.h>
+
+/* undef for production */
+#define HIGHMEM_DEBUG 1
+
+/* 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 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);
+
+extern inline unsigned long kmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (page < highmem_start_page)
+ return (unsigned long) page_address(page);
+ return kmap_high(page);
+}
+
+extern 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.
+ */
+extern inline unsigned long kmap_atomic(struct page *page, enum km_type type)
+{
+ unsigned long idx;
+ unsigned long vaddr;
+
+ if (page < highmem_start_page)
+ return (unsigned long) page_address(page);
+
+ idx = type + KM_TYPE_NR*smp_processor_id();
+ vaddr = FIX_KMAP_BEGIN + idx * PAGE_SIZE;
+
+/* XXX Fix - Anton */
+#if 0
+ __flush_cache_one(vaddr);
+#else
+ flush_cache_all();
+#endif
+
+#if HIGHMEM_DEBUG
+ if (!pte_none(*(kmap_pte+idx)))
+ BUG();
+#endif
+ set_pte(kmap_pte+idx, mk_pte(page, kmap_prot));
+/* XXX Fix - Anton */
+#if 0
+ __flush_tlb_one(vaddr);
+#else
+ flush_tlb_all();
+#endif
+
+ return vaddr;
+}
+
+extern inline void kunmap_atomic(unsigned long vaddr, enum km_type type)
+{
+#if HIGHMEM_DEBUG
+ unsigned long idx = type + KM_TYPE_NR*smp_processor_id();
+
+#if 0
+ if (vaddr < FIXADDR_START) // FIXME
+ return;
+#endif
+
+ if (vaddr != FIX_KMAP_BEGIN + idx * PAGE_SIZE)
+ BUG();
+
+/* XXX Fix - Anton */
+#if 0
+ __flush_cache_one(vaddr);
+#else
+ flush_cache_all();
+#endif
+
+ /*
+ * force other mappings to Oops if they'll try to access
+ * this pte without first remap it
+ */
+ pte_clear(kmap_pte+idx);
+/* XXX Fix - Anton */
+#if 0
+ __flush_tlb_one(vaddr);
+#else
+ flush_tlb_all();
+#endif
+#endif
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_HIGHMEM_H */