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-rw-r--r--kernel/arch/s390/mm/page-states.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/kernel/arch/s390/mm/page-states.c b/kernel/arch/s390/mm/page-states.c
new file mode 100644
index 000000000..a90d45e9d
--- /dev/null
+++ b/kernel/arch/s390/mm/page-states.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright IBM Corp. 2008
+ *
+ * Guest page hinting for unused pages.
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+
+#define ESSA_SET_STABLE 1
+#define ESSA_SET_UNUSED 2
+
+static int cmma_flag = 1;
+
+static int __init cmma(char *str)
+{
+ char *parm;
+
+ parm = strstrip(str);
+ if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) {
+ cmma_flag = 1;
+ return 1;
+ }
+ cmma_flag = 0;
+ if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0)
+ return 1;
+ return 0;
+}
+__setup("cmma=", cmma);
+
+void __init cmma_init(void)
+{
+ register unsigned long tmp asm("0") = 0;
+ register int rc asm("1") = -EOPNOTSUPP;
+
+ if (!cmma_flag)
+ return;
+ asm volatile(
+ " .insn rrf,0xb9ab0000,%1,%1,0,0\n"
+ "0: la %0,0\n"
+ "1:\n"
+ EX_TABLE(0b,1b)
+ : "+&d" (rc), "+&d" (tmp));
+ if (rc)
+ cmma_flag = 0;
+}
+
+static inline void set_page_unstable(struct page *page, int order)
+{
+ int i, rc;
+
+ for (i = 0; i < (1 << order); i++)
+ asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+ : "=&d" (rc)
+ : "a" (page_to_phys(page + i)),
+ "i" (ESSA_SET_UNUSED));
+}
+
+void arch_free_page(struct page *page, int order)
+{
+ if (!cmma_flag)
+ return;
+ set_page_unstable(page, order);
+}
+
+static inline void set_page_stable(struct page *page, int order)
+{
+ int i, rc;
+
+ for (i = 0; i < (1 << order); i++)
+ asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
+ : "=&d" (rc)
+ : "a" (page_to_phys(page + i)),
+ "i" (ESSA_SET_STABLE));
+}
+
+void arch_alloc_page(struct page *page, int order)
+{
+ if (!cmma_flag)
+ return;
+ set_page_stable(page, order);
+}
+
+void arch_set_page_states(int make_stable)
+{
+ unsigned long flags, order, t;
+ struct list_head *l;
+ struct page *page;
+ struct zone *zone;
+
+ if (!cmma_flag)
+ return;
+ if (make_stable)
+ drain_local_pages(NULL);
+ for_each_populated_zone(zone) {
+ spin_lock_irqsave(&zone->lock, flags);
+ for_each_migratetype_order(order, t) {
+ list_for_each(l, &zone->free_area[order].free_list[t]) {
+ page = list_entry(l, struct page, lru);
+ if (make_stable)
+ set_page_stable(page, order);
+ else
+ set_page_unstable(page, order);
+ }
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+ }
+}