From: Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: s390/mm: add missing virt_to_pfn() etc. helper functions
Patch-mainline: v4.14-rc1
Git-commit: 16f48641716000ae674159a021c93632d172f466
References: bnc#1066983, LTC#159171

Description:  vmcp: make use of contiguous memory allocator
Symptom:      The vmcp tool fails to execute a cp command because the kernel
              was unable to allocate memory.
Problem:      Allocation of memory for the response area of the diagnose 8
              command may require the kernel to allocate large contiguous
              memory areas. If memory is fragmented, large order allocations
              can likely fail and this causes vmcp to fail.
Solution:     Make use of the contiguous memory allocator. This should make
              sure that allocation of large response buffers will almost
              always succeed.
Reproduction: -

Upstream-Description:

              s390/mm: add missing virt_to_pfn() etc. helper functions

              Add all the missing little helper functions like virt_to_pfn(),
              phys_to_page(), etc.  While we had a couple of these helper functions
              like e.g. page_to_phys() the other functions were missing, which is
              quite annoying if one is looking for exactly such a function.

              Therefore finally add all those little helper functions.

              Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
              Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>


Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 arch/s390/include/asm/page.h |   24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -145,16 +145,26 @@ static inline int devmem_is_allowed(unsi
 
 #endif /* !__ASSEMBLY__ */
 
-#define __PAGE_OFFSET           0x0UL
-#define PAGE_OFFSET             0x0UL
-#define __pa(x)                 (unsigned long)(x)
-#define __va(x)                 (void *)(unsigned long)(x)
-#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-#define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
-#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
+#define __PAGE_OFFSET		0x0UL
+#define PAGE_OFFSET		0x0UL
+
+#define __pa(x)			((unsigned long)(x))
+#define __va(x)			((void *)(unsigned long)(x))
+
+#define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)
 #define pfn_to_virt(pfn)	__va((pfn) << PAGE_SHIFT)
+
+#define virt_to_page(kaddr)	pfn_to_page(virt_to_pfn(kaddr))
 #define page_to_virt(page)	pfn_to_virt(page_to_pfn(page))
 
+#define phys_to_pfn(kaddr)	((kaddr) >> PAGE_SHIFT)
+#define pfn_to_phys(pfn)	((pfn) << PAGE_SHIFT)
+
+#define phys_to_page(kaddr)	pfn_to_page(phys_to_pfn(kaddr))
+#define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
+
+#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
+
 #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)