Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

5 files changed, 39 insertions, 14 deletions

diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 694c4fca9f5d..3e70fb7a8d83 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -20,6 +20,7 @@ choice
 
 config M68KCLASSIC
 	bool "Classic M68K CPU family support"
+	select HAVE_ARCH_PFN_VALID
 
 config COLDFIRE
 	bool "Coldfire CPU family support"
@@ -373,16 +374,38 @@ config RMW_INSNS
 config SINGLE_MEMORY_CHUNK
 	bool "Use one physical chunk of memory only" if ADVANCED && !SUN3
 	depends on MMU
-	default y if SUN3
-	select NEED_MULTIPLE_NODES
+	default y if SUN3 || MMU_COLDFIRE
 	help
 	  Ignore all but the first contiguous chunk of physical memory for VM
 	  purposes.  This will save a few bytes kernel size and may speed up
-	  some operations.  Say N if not sure.
+	  some operations.
+	  When this option os set to N, you may want to lower "Maximum zone
+	  order" to save memory that could be wasted for unused memory map.
+	  Say N if not sure.
 
 config ARCH_DISCONTIGMEM_ENABLE
+	depends on BROKEN
 	def_bool MMU && !SINGLE_MEMORY_CHUNK
 
+config FORCE_MAX_ZONEORDER
+	int "Maximum zone order" if ADVANCED
+	depends on !SINGLE_MEMORY_CHUNK
+	default "11"
+	help
+	  The kernel memory allocator divides physically contiguous memory
+	  blocks into "zones", where each zone is a power of two number of
+	  pages.  This option selects the largest power of two that the kernel
+	  keeps in the memory allocator.  If you need to allocate very large
+	  blocks of physically contiguous memory, then you may need to
+	  increase this value.
+
+	  For systems that have holes in their physical address space this
+	  value also defines the minimal size of the hole that allows
+	  freeing unused memory map.
+
+	  This config option is actually maximum order plus one. For example,
+	  a value of 11 means that the largest free memory block is 2^10 pages.
+
 config 060_WRITETHROUGH
 	bool "Use write-through caching for 68060 supervisor accesses"
 	depends on ADVANCED && M68060
@@ -406,7 +429,7 @@ config M68K_L2_CACHE
 config NODES_SHIFT
 	int
 	default "3"
-	depends on !SINGLE_MEMORY_CHUNK
+	depends on DISCONTIGMEM
 
 config CPU_HAS_NO_BITFIELDS
 	bool
diff --git a/arch/m68k/include/asm/page.h b/arch/m68k/include/asm/page.h
index 2614a1206f2f..6116d7094292 100644
--- a/arch/m68k/include/asm/page.h
+++ b/arch/m68k/include/asm/page.h
@@ -62,8 +62,10 @@ extern unsigned long _ramend;
 #include <asm/page_no.h>
 #endif
 
+#ifdef CONFIG_DISCONTIGMEM
 #define __phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
 #define __pfn_to_phys(pfn)	PFN_PHYS(pfn)
+#endif
 
 #include <asm-generic/getorder.h>
 
diff --git a/arch/m68k/include/asm/page_mm.h b/arch/m68k/include/asm/page_mm.h
index e6b75992192b..7f5912af2a52 100644
--- a/arch/m68k/include/asm/page_mm.h
+++ b/arch/m68k/include/asm/page_mm.h
@@ -126,7 +126,7 @@ static inline void *__va(unsigned long x)
 
 extern int m68k_virt_to_node_shift;
 
-#ifdef CONFIG_SINGLE_MEMORY_CHUNK
+#ifndef CONFIG_DISCONTIGMEM
 #define __virt_to_node(addr)	(&pg_data_map[0])
 #else
 extern struct pglist_data *pg_data_table[];
@@ -153,6 +153,7 @@ static inline __attribute_const__ int __virt_to_node_shift(void)
 	pfn_to_virt(page_to_pfn(page));					\
 })
 
+#ifdef CONFIG_DISCONTIGMEM
 #define pfn_to_page(pfn) ({						\
 	unsigned long __pfn = (pfn);					\
 	struct pglist_data *pgdat;					\
@@ -165,6 +166,10 @@ static inline __attribute_const__ int __virt_to_node_shift(void)
 	pgdat = &pg_data_map[page_to_nid(__p)];				\
 	((__p) - pgdat->node_mem_map) + pgdat->node_start_pfn;		\
 })
+#else
+#define ARCH_PFN_OFFSET (m68k_memory[0].addr)
+#include <asm-generic/memory_model.h>
+#endif
 
 #define virt_addr_valid(kaddr)	((void *)(kaddr) >= (void *)PAGE_OFFSET && (void *)(kaddr) < high_memory)
 #define pfn_valid(pfn)		virt_addr_valid(pfn_to_virt(pfn))
diff --git a/arch/m68k/include/asm/virtconvert.h b/arch/m68k/include/asm/virtconvert.h
index dfe43083b579..ca91b32dc6ef 100644
--- a/arch/m68k/include/asm/virtconvert.h
+++ b/arch/m68k/include/asm/virtconvert.h
@@ -29,12 +29,7 @@ static inline void *phys_to_virt(unsigned long address)
 }
 
 /* Permanent address of a page. */
-#if defined(CONFIG_MMU) && defined(CONFIG_SINGLE_MEMORY_CHUNK)
-#define page_to_phys(page) \
-	__pa(PAGE_OFFSET + (((page) - pg_data_map[0].node_mem_map) << PAGE_SHIFT))
-#else
 #define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
-#endif
 
 /*
  * IO bus memory addresses are 1:1 with the physical address,
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 53040857a9ed..14c1e541451c 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -42,19 +42,19 @@ EXPORT_SYMBOL(empty_zero_page);
 
 #ifdef CONFIG_MMU
 
+int m68k_virt_to_node_shift;
+
+#ifdef CONFIG_DISCONTIGMEM
 pg_data_t pg_data_map[MAX_NUMNODES];
 EXPORT_SYMBOL(pg_data_map);
 
-int m68k_virt_to_node_shift;
-
-#ifndef CONFIG_SINGLE_MEMORY_CHUNK
 pg_data_t *pg_data_table[65];
 EXPORT_SYMBOL(pg_data_table);
 #endif
 
 void __init m68k_setup_node(int node)
 {
-#ifndef CONFIG_SINGLE_MEMORY_CHUNK
+#ifdef CONFIG_DISCONTIGMEM
 	struct m68k_mem_info *info = m68k_memory + node;
 	int i, end;