patch-2.4.20 linux-2.4.20/arch/sparc/mm/highmem.c
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- Lines: 85
- Date:
Thu Nov 28 15:53:12 2002
- Orig file:
linux-2.4.19/arch/sparc/mm/highmem.c
- Orig date:
Wed Dec 31 16:00:00 1969
diff -urN linux-2.4.19/arch/sparc/mm/highmem.c linux-2.4.20/arch/sparc/mm/highmem.c
@@ -0,0 +1,84 @@
+/*
+ * highmem.c: virtual kernel memory mappings for high memory
+ *
+ * Provides kernel-static versions of atomic kmap functions originally
+ * found as inlines in include/asm-sparc/highmem.h. These became
+ * needed as kmap_atomic() and kunmap_atomic() started getting
+ * called from within modules.
+ * -- Tomas Szepe <szepe@pinerecords.com>, September 2002
+ */
+
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <asm/pgalloc.h>
+
+/*
+ * 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.
+ */
+void *kmap_atomic(struct page *page, enum km_type type)
+{
+ unsigned long idx;
+ unsigned long vaddr;
+
+ if (page < highmem_start_page)
+ return 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 (void *) vaddr;
+}
+
+void kunmap_atomic(void *kvaddr, enum km_type type)
+{
+ unsigned long vaddr = (unsigned long) kvaddr;
+ unsigned long idx = type + KM_TYPE_NR * smp_processor_id();
+
+ if (vaddr < fix_kmap_begin) /* FIXME */
+ return;
+
+ if (vaddr != fix_kmap_begin + idx * PAGE_SIZE)
+ BUG();
+
+/* XXX Fix - Anton */
+#if 0
+ __flush_cache_one(vaddr);
+#else
+ flush_cache_all();
+#endif
+
+#ifdef HIGHMEM_DEBUG
+ /*
+ * Force other mappings to oops if they try to access
+ * this pte without first remapping it.
+ */
+ pte_clear(kmap_pte + idx);
+/* XXX Fix - Anton */
+#if 0
+ __flush_tlb_one(vaddr);
+#else
+ flush_tlb_all();
+#endif
+#endif
+}
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