[S390] Cleanup page table definitions.

- De-confuse the defines for the address-space-control-elements
  and the segment/region table entries.
- Create out of line functions for page table allocation / freeing.
- Simplify get_shadow_xxx functions.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
new file mode 100644
index 00000000000..e60e0ae1340
--- /dev/null
+++ b/arch/s390/mm/pgtable.c
@@ -0,0 +1,94 @@
+/*
+ *  arch/s390/mm/pgtable.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/quicklist.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+#ifndef CONFIG_64BIT
+#define ALLOC_ORDER	1
+#else
+#define ALLOC_ORDER	2
+#endif
+
+unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
+{
+	struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+
+	if (!page)
+		return NULL;
+	page->index = 0;
+	if (noexec) {
+		struct page *shadow = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+		if (!shadow) {
+			__free_pages(page, ALLOC_ORDER);
+			return NULL;
+		}
+		page->index = page_to_phys(shadow);
+	}
+	return (unsigned long *) page_to_phys(page);
+}
+
+void crst_table_free(unsigned long *table)
+{
+	unsigned long *shadow = get_shadow_table(table);
+
+	if (shadow)
+		free_pages((unsigned long) shadow, ALLOC_ORDER);
+	free_pages((unsigned long) table, ALLOC_ORDER);
+}
+
+/*
+ * page table entry allocation/free routines.
+ */
+unsigned long *page_table_alloc(int noexec)
+{
+	struct page *page = alloc_page(GFP_KERNEL);
+	unsigned long *table;
+
+	if (!page)
+		return NULL;
+	page->index = 0;
+	if (noexec) {
+		struct page *shadow = alloc_page(GFP_KERNEL);
+		if (!shadow) {
+			__free_page(page);
+			return NULL;
+		}
+		table = (unsigned long *) page_to_phys(shadow);
+		clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+		page->index = (addr_t) table;
+	}
+	table = (unsigned long *) page_to_phys(page);
+	clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+	return table;
+}
+
+void page_table_free(unsigned long *table)
+{
+	unsigned long *shadow = get_shadow_pte(table);
+
+	if (shadow)
+		free_page((unsigned long) shadow);
+	free_page((unsigned long) table);
+
+}