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
  ...

6 files changed, 53 insertions, 106 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 39b25a5a591b..6e67d6110249 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -288,6 +288,7 @@ config ARCH_SELECT_MEMORY_MODEL
 
 config ARCH_DISCONTIGMEM_ENABLE
 	def_bool y
+	depends on BROKEN
 	help
 	  Say Y to support efficient handling of discontiguous physical memory,
 	  for architectures which are either NUMA (Non-Uniform Memory Access)
@@ -299,12 +300,11 @@ config ARCH_FLATMEM_ENABLE
 
 config ARCH_SPARSEMEM_ENABLE
 	def_bool y
-	depends on ARCH_DISCONTIGMEM_ENABLE
 	select SPARSEMEM_VMEMMAP_ENABLE
 
-config ARCH_DISCONTIGMEM_DEFAULT
+config ARCH_SPARSEMEM_DEFAULT
 	def_bool y
-	depends on ARCH_DISCONTIGMEM_ENABLE
+	depends on ARCH_SPARSEMEM_ENABLE
 
 config NUMA
 	bool "NUMA support"
@@ -329,7 +329,7 @@ config NODES_SHIFT
 # VIRTUAL_MEM_MAP has been retained for historical reasons.
 config VIRTUAL_MEM_MAP
 	bool "Virtual mem map"
-	depends on !SPARSEMEM
+	depends on !SPARSEMEM && !FLATMEM
 	default y
 	help
 	  Say Y to compile the kernel with support for a virtual mem map.
@@ -342,9 +342,6 @@ config HOLES_IN_ZONE
 	bool
 	default y if VIRTUAL_MEM_MAP
 
-config HAVE_ARCH_EARLY_PFN_TO_NID
-	def_bool NUMA && SPARSEMEM
-
 config HAVE_ARCH_NODEDATA_EXTENSION
 	def_bool y
 	depends on NUMA
diff --git a/arch/ia64/include/asm/meminit.h b/arch/ia64/include/asm/meminit.h
index 092f1c91b36c..e789c0818edb 100644
--- a/arch/ia64/include/asm/meminit.h
+++ b/arch/ia64/include/asm/meminit.h
@@ -59,10 +59,8 @@ extern int reserve_elfcorehdr(u64 *start, u64 *end);
 extern int register_active_ranges(u64 start, u64 len, int nid);
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
-# define LARGE_GAP	0x40000000 /* Use virtual mem map if hole is > than this */
   extern unsigned long VMALLOC_END;
   extern struct page *vmem_map;
-  extern int find_largest_hole(u64 start, u64 end, void *arg);
   extern int create_mem_map_page_table(u64 start, u64 end, void *arg);
   extern int vmemmap_find_next_valid_pfn(int, int);
 #else
diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index e30e360beef8..bfc4ecd0a2ab 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -19,15 +19,12 @@
 #include <linux/mm.h>
 #include <linux/nmi.h>
 #include <linux/swap.h>
+#include <linux/sizes.h>
 
 #include <asm/meminit.h>
 #include <asm/sections.h>
 #include <asm/mca.h>
 
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-static unsigned long max_gap;
-#endif
-
 /* physical address where the bootmem map is located */
 unsigned long bootmap_start;
 
@@ -166,6 +163,32 @@ find_memory (void)
 	alloc_per_cpu_data();
 }
 
+static int __init find_largest_hole(u64 start, u64 end, void *arg)
+{
+	u64 *max_gap = arg;
+
+	static u64 last_end = PAGE_OFFSET;
+
+	/* NOTE: this algorithm assumes efi memmap table is ordered */
+
+	if (*max_gap < (start - last_end))
+		*max_gap = start - last_end;
+	last_end = end;
+	return 0;
+}
+
+static void __init verify_gap_absence(void)
+{
+	unsigned long max_gap;
+
+	/* Forbid FLATMEM if hole is > than 1G */
+	efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
+	if (max_gap >= SZ_1G)
+		panic("Cannot use FLATMEM with %ldMB hole\n"
+		      "Please switch over to SPARSEMEM\n",
+		      (max_gap >> 20));
+}
+
 /*
  * Set up the page tables.
  */
@@ -177,37 +200,12 @@ paging_init (void)
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
 
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
-#ifdef CONFIG_ZONE_DMA32
 	max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 	max_zone_pfns[ZONE_DMA32] = max_dma;
-#endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-	efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
-	if (max_gap < LARGE_GAP) {
-		vmem_map = (struct page *) 0;
-	} else {
-		unsigned long map_size;
-
-		/* allocate virtual_mem_map */
+	verify_gap_absence();
 
-		map_size = PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *
-			sizeof(struct page));
-		VMALLOC_END -= map_size;
-		vmem_map = (struct page *) VMALLOC_END;
-		efi_memmap_walk(create_mem_map_page_table, NULL);
-
-		/*
-		 * alloc_node_mem_map makes an adjustment for mem_map
-		 * which isn't compatible with vmem_map.
-		 */
-		NODE_DATA(0)->node_mem_map = vmem_map +
-			find_min_pfn_with_active_regions();
-
-		printk("Virtual mem_map starts at 0x%p\n", mem_map);
-	}
-#endif /* !CONFIG_VIRTUAL_MEM_MAP */
 	free_area_init(max_zone_pfns);
 	zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
 }
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index dbe829fc5298..c7311131156e 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -584,6 +584,25 @@ void call_pernode_memory(unsigned long start, unsigned long len, void *arg)
 	}
 }
 
+static void __init virtual_map_init(void)
+{
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+	int node;
+
+	VMALLOC_END -= PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *
+		sizeof(struct page));
+	vmem_map = (struct page *) VMALLOC_END;
+	efi_memmap_walk(create_mem_map_page_table, NULL);
+	printk("Virtual mem_map starts at 0x%p\n", vmem_map);
+
+	for_each_online_node(node) {
+		unsigned long pfn_offset = mem_data[node].min_pfn;
+
+		NODE_DATA(node)->node_mem_map = vmem_map + pfn_offset;
+	}
+#endif
+}
+
 /**
  * paging_init - setup page tables
  *
@@ -593,38 +612,17 @@ void call_pernode_memory(unsigned long start, unsigned long len, void *arg)
 void __init paging_init(void)
 {
 	unsigned long max_dma;
-	unsigned long pfn_offset = 0;
-	unsigned long max_pfn = 0;
-	int node;
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
 
 	max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 
 	sparse_init();
 
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-	VMALLOC_END -= PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *
-		sizeof(struct page));
-	vmem_map = (struct page *) VMALLOC_END;
-	efi_memmap_walk(create_mem_map_page_table, NULL);
-	printk("Virtual mem_map starts at 0x%p\n", vmem_map);
-#endif
-
-	for_each_online_node(node) {
-		pfn_offset = mem_data[node].min_pfn;
-
-#ifdef CONFIG_VIRTUAL_MEM_MAP
-		NODE_DATA(node)->node_mem_map = vmem_map + pfn_offset;
-#endif
-		if (mem_data[node].max_pfn > max_pfn)
-			max_pfn = mem_data[node].max_pfn;
-	}
+	virtual_map_init();
 
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
-#ifdef CONFIG_ZONE_DMA32
 	max_zone_pfns[ZONE_DMA32] = max_dma;
-#endif
-	max_zone_pfns[ZONE_NORMAL] = max_pfn;
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 	free_area_init(max_zone_pfns);
 
 	zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index ef12e097f318..9b5acf8fb092 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -574,20 +574,6 @@ ia64_pfn_valid (unsigned long pfn)
 }
 EXPORT_SYMBOL(ia64_pfn_valid);
 
-int __init find_largest_hole(u64 start, u64 end, void *arg)
-{
-	u64 *max_gap = arg;
-
-	static u64 last_end = PAGE_OFFSET;
-
-	/* NOTE: this algorithm assumes efi memmap table is ordered */
-
-	if (*max_gap < (start - last_end))
-		*max_gap = start - last_end;
-	last_end = end;
-	return 0;
-}
-
 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 
 int __init register_active_ranges(u64 start, u64 len, int nid)
diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
index f34964271101..46b6e5f3a40f 100644
--- a/arch/ia64/mm/numa.c
+++ b/arch/ia64/mm/numa.c
@@ -58,36 +58,6 @@ paddr_to_nid(unsigned long paddr)
 EXPORT_SYMBOL(paddr_to_nid);
 
 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
-/*
- * Because of holes evaluate on section limits.
- * If the section of memory exists, then return the node where the section
- * resides.  Otherwise return node 0 as the default.  This is used by
- * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
- * the section resides.
- */
-int __meminit __early_pfn_to_nid(unsigned long pfn,
-					struct mminit_pfnnid_cache *state)
-{
-	int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
-
-	if (section >= state->last_start && section < state->last_end)
-		return state->last_nid;
-
-	for (i = 0; i < num_node_memblks; i++) {
-		ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
-		esec = (node_memblk[i].start_paddr + node_memblk[i].size +
-			((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
-		if (section >= ssec && section < esec) {
-			state->last_start = ssec;
-			state->last_end = esec;
-			state->last_nid = node_memblk[i].nid;
-			return node_memblk[i].nid;
-		}
-	}
-
-	return -1;
-}
-
 void numa_clear_node(int cpu)
 {
 	unmap_cpu_from_node(cpu, NUMA_NO_NODE);