[S390] replace diag10() with diag10_range() function

Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 16 insertions, 24 deletions

diff --git a/arch/s390/include/asm/diag.h b/arch/s390/include/asm/diag.h
index 72b2e2f2d32d..7e91c58072e2 100644
--- a/arch/s390/include/asm/diag.h
+++ b/arch/s390/include/asm/diag.h
@@ -9,9 +9,22 @@
 #define _ASM_S390_DIAG_H
 
 /*
- * Diagnose 10: Release pages
+ * Diagnose 10: Release page range
  */
-extern void diag10(unsigned long addr);
+static inline void diag10_range(unsigned long start_pfn, unsigned long num_pfn)
+{
+        unsigned long start_addr, end_addr;
+
+        start_addr = start_pfn << PAGE_SHIFT;
+        end_addr = (start_pfn + num_pfn - 1) << PAGE_SHIFT;
+
+        asm volatile(
+                "0:     diag    %0,%1,0x10\n"
+                "1:\n"
+                EX_TABLE(0b, 1b)
+                EX_TABLE(1b, 1b)
+                : : "a" (start_addr), "a" (end_addr));
+}
 
 /*
  * Diagnose 14: Input spool file manipulation
diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c
index c032d11da8a1..8237fc07ac79 100644
--- a/arch/s390/kernel/diag.c
+++ b/arch/s390/kernel/diag.c
@@ -9,27 +9,6 @@
 #include <asm/diag.h>
 
 /*
- * Diagnose 10: Release pages
- */
-void diag10(unsigned long addr)
-{
-        if (addr >= 0x7ff00000)
-                return;
-        asm volatile(
-#ifdef CONFIG_64BIT
-                "       sam31\n"
-                "       diag    %0,%0,0x10\n"
-                "0:     sam64\n"
-#else
-                "       diag    %0,%0,0x10\n"
-                "0:\n"
-#endif
-                EX_TABLE(0b, 0b)
-                : : "a" (addr));
-}
-EXPORT_SYMBOL(diag10);
-
-/*
  * Diagnose 14: Input spool file manipulation
  */
 int diag14(unsigned long rx, unsigned long ry1, unsigned long subcode)
diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index c66ffd8dbbb7..1f1dba9dcf58 100644
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -91,7 +91,7 @@ static long cmm_alloc_pages(long nr, long *counter,
                         } else
                                 free_page((unsigned long) npa);
                 }
-                diag10(addr);
+                diag10_range(addr >> PAGE_SHIFT, 1);
                 pa->pages[pa->index++] = addr;
                 (*counter)++;
                 spin_unlock(&cmm_lock);