Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c

8 files changed, 1426 insertions, 379 deletions

diff --git a/mm/Makefile b/mm/Makefile
index 147a7a7873c4..ea4b18bd3960 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -33,7 +33,7 @@ obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
-ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
 obj-$(CONFIG_SMP) += percpu.o
 else
 obj-$(CONFIG_SMP) += allocpercpu.o
diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index dfdee6a47359..df34ceae0c67 100644
--- a/mm/allocpercpu.c
+++ b/mm/allocpercpu.c
@@ -5,6 +5,8 @@
  */
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/bootmem.h>
+#include <asm/sections.h>
 
 #ifndef cache_line_size
 #define cache_line_size()	L1_CACHE_BYTES
@@ -147,3 +149,29 @@ void free_percpu(void *__pdata)
 	kfree(__percpu_disguise(__pdata));
 }
 EXPORT_SYMBOL_GPL(free_percpu);
+
+/*
+ * Generic percpu area setup.
+ */
+#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+
+EXPORT_SYMBOL(__per_cpu_offset);
+
+void __init setup_per_cpu_areas(void)
+{
+	unsigned long size, i;
+	char *ptr;
+	unsigned long nr_possible_cpus = num_possible_cpus();
+
+	/* Copy section for each CPU (we discard the original) */
+	size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
+	ptr = alloc_bootmem_pages(size * nr_possible_cpus);
+
+	for_each_possible_cpu(i) {
+		__per_cpu_offset[i] = ptr - __per_cpu_start;
+		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+		ptr += size;
+	}
+}
+#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
diff --git a/mm/kmemleak-test.c b/mm/kmemleak-test.c
index d5292fc6f523..177a5169bbde 100644
--- a/mm/kmemleak-test.c
+++ b/mm/kmemleak-test.c
@@ -36,7 +36,7 @@ struct test_node {
 };
 
 static LIST_HEAD(test_list);
-static DEFINE_PER_CPU(void *, test_pointer);
+static DEFINE_PER_CPU(void *, kmemleak_test_pointer);
 
 /*
  * Some very simple testing. This function needs to be extended for
@@ -86,9 +86,9 @@ static int __init kmemleak_test_init(void)
 	}
 
 	for_each_possible_cpu(i) {
-		per_cpu(test_pointer, i) = kmalloc(129, GFP_KERNEL);
+		per_cpu(kmemleak_test_pointer, i) = kmalloc(129, GFP_KERNEL);
 		pr_info("kmemleak: kmalloc(129) = %p\n",
-			per_cpu(test_pointer, i));
+			per_cpu(kmemleak_test_pointer, i));
 	}
 
 	return 0;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 25e7770309b8..dd73d29c15a8 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -604,6 +604,8 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
 	}
 }
 
+static DEFINE_PER_CPU(unsigned long, bdp_ratelimits) = 0;
+
 /**
  * balance_dirty_pages_ratelimited_nr - balance dirty memory state
  * @mapping: address_space which was dirtied
@@ -621,7 +623,6 @@ void set_page_dirty_balance(struct page *page, int page_mkwrite)
 void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 					unsigned long nr_pages_dirtied)
 {
-	static DEFINE_PER_CPU(unsigned long, ratelimits) = 0;
 	unsigned long ratelimit;
 	unsigned long *p;
 
@@ -634,7 +635,7 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 	 * tasks in balance_dirty_pages(). Period.
 	 */
 	preempt_disable();
-	p =  &__get_cpu_var(ratelimits);
+	p =  &__get_cpu_var(bdp_ratelimits);
 	*p += nr_pages_dirtied;
 	if (unlikely(*p >= ratelimit)) {
 		*p = 0;
diff --git a/mm/percpu.c b/mm/percpu.c
index 3311c8919f37..43d8cacfdaa5 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -8,12 +8,13 @@
  *
  * This is percpu allocator which can handle both static and dynamic
  * areas.  Percpu areas are allocated in chunks in vmalloc area.  Each
- * chunk is consisted of nr_cpu_ids units and the first chunk is used
- * for static percpu variables in the kernel image (special boot time
- * alloc/init handling necessary as these areas need to be brought up
- * before allocation services are running).  Unit grows as necessary
- * and all units grow or shrink in unison.  When a chunk is filled up,
- * another chunk is allocated.  ie. in vmalloc area
+ * chunk is consisted of boot-time determined number of units and the
+ * first chunk is used for static percpu variables in the kernel image
+ * (special boot time alloc/init handling necessary as these areas
+ * need to be brought up before allocation services are running).
+ * Unit grows as necessary and all units grow or shrink in unison.
+ * When a chunk is filled up, another chunk is allocated.  ie. in
+ * vmalloc area
  *
  *  c0                           c1                         c2
  *  -------------------          -------------------        ------------
@@ -22,11 +23,13 @@
  *
  * Allocation is done in offset-size areas of single unit space.  Ie,
  * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0,
- * c1:u1, c1:u2 and c1:u3.  Percpu access can be done by configuring
- * percpu base registers pcpu_unit_size apart.
+ * c1:u1, c1:u2 and c1:u3.  On UMA, units corresponds directly to
+ * cpus.  On NUMA, the mapping can be non-linear and even sparse.
+ * Percpu access can be done by configuring percpu base registers
+ * according to cpu to unit mapping and pcpu_unit_size.
  *
- * There are usually many small percpu allocations many of them as
- * small as 4 bytes.  The allocator organizes chunks into lists
+ * There are usually many small percpu allocations many of them being
+ * as small as 4 bytes.  The allocator organizes chunks into lists
  * according to free size and tries to allocate from the fullest one.
  * Each chunk keeps the maximum contiguous area size hint which is
  * guaranteed to be eqaul to or larger than the maximum contiguous
@@ -43,7 +46,7 @@
  *
  * To use this allocator, arch code should do the followings.
  *
- * - define CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
+ * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA
  *
  * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate
  *   regular address to percpu pointer and back if they need to be
@@ -55,7 +58,9 @@
 
 #include <linux/bitmap.h>
 #include <linux/bootmem.h>
+#include <linux/err.h>
 #include <linux/list.h>
+#include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -89,25 +94,38 @@ struct pcpu_chunk {
 	struct list_head	list;		/* linked to pcpu_slot lists */
 	int			free_size;	/* free bytes in the chunk */
 	int			contig_hint;	/* max contiguous size hint */
-	struct vm_struct	*vm;		/* mapped vmalloc region */
+	void			*base_addr;	/* base address of this chunk */
 	int			map_used;	/* # of map entries used */
 	int			map_alloc;	/* # of map entries allocated */
 	int			*map;		/* allocation map */
+	struct vm_struct	**vms;		/* mapped vmalloc regions */
 	bool			immutable;	/* no [de]population allowed */
-	struct page		**page;		/* points to page array */
-	struct page		*page_ar[];	/* #cpus * UNIT_PAGES */
+	unsigned long		populated[];	/* populated bitmap */
 };
 
 static int pcpu_unit_pages __read_mostly;
 static int pcpu_unit_size __read_mostly;
-static int pcpu_chunk_size __read_mostly;
+static int pcpu_nr_units __read_mostly;
+static int pcpu_atom_size __read_mostly;
 static int pcpu_nr_slots __read_mostly;
 static size_t pcpu_chunk_struct_size __read_mostly;
 
+/* cpus with the lowest and highest unit numbers */
+static unsigned int pcpu_first_unit_cpu __read_mostly;
+static unsigned int pcpu_last_unit_cpu __read_mostly;
+
 /* the address of the first chunk which starts with the kernel static area */
 void *pcpu_base_addr __read_mostly;
 EXPORT_SYMBOL_GPL(pcpu_base_addr);
 
+static const int *pcpu_unit_map __read_mostly;		/* cpu -> unit */
+const unsigned long *pcpu_unit_offsets __read_mostly;	/* cpu -> unit offset */
+
+/* group information, used for vm allocation */
+static int pcpu_nr_groups __read_mostly;
+static const unsigned long *pcpu_group_offsets __read_mostly;
+static const size_t *pcpu_group_sizes __read_mostly;
+
 /*
  * The first chunk which always exists.  Note that unlike other
  * chunks, this one can be allocated and mapped in several different
@@ -129,9 +147,9 @@ static int pcpu_reserved_chunk_limit;
  * Synchronization rules.
  *
  * There are two locks - pcpu_alloc_mutex and pcpu_lock.  The former
- * protects allocation/reclaim paths, chunks and chunk->page arrays.
- * The latter is a spinlock and protects the index data structures -
- * chunk slots, chunks and area maps in chunks.
+ * protects allocation/reclaim paths, chunks, populated bitmap and
+ * vmalloc mapping.  The latter is a spinlock and protects the index
+ * data structures - chunk slots, chunks and area maps in chunks.
  *
  * During allocation, pcpu_alloc_mutex is kept locked all the time and
  * pcpu_lock is grabbed and released as necessary.  All actual memory
@@ -178,31 +196,23 @@ static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
 
 static int pcpu_page_idx(unsigned int cpu, int page_idx)
 {
-	return cpu * pcpu_unit_pages + page_idx;
-}
-
-static struct page **pcpu_chunk_pagep(struct pcpu_chunk *chunk,
-				      unsigned int cpu, int page_idx)
-{
-	return &chunk->page[pcpu_page_idx(cpu, page_idx)];
+	return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx;
 }
 
 static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,
 				     unsigned int cpu, int page_idx)
 {
-	return (unsigned long)chunk->vm->addr +
-		(pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT);
+	return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] +
+		(page_idx << PAGE_SHIFT);
 }
 
-static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk,
-				     int page_idx)
+static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
+				    unsigned int cpu, int page_idx)
 {
-	/*
-	 * Any possible cpu id can be used here, so there's no need to
-	 * worry about preemption or cpu hotplug.
-	 */
-	return *pcpu_chunk_pagep(chunk, raw_smp_processor_id(),
-				 page_idx) != NULL;
+	/* must not be used on pre-mapped chunk */
+	WARN_ON(chunk->immutable);
+
+	return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx));
 }
 
 /* set the pointer to a chunk in a page struct */
@@ -217,6 +227,34 @@ static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page)
 	return (struct pcpu_chunk *)page->index;
 }
 
+static void pcpu_next_unpop(struct pcpu_chunk *chunk, int *rs, int *re, int end)
+{
+	*rs = find_next_zero_bit(chunk->populated, end, *rs);
+	*re = find_next_bit(chunk->populated, end, *rs + 1);
+}
+
+static void pcpu_next_pop(struct pcpu_chunk *chunk, int *rs, int *re, int end)
+{
+	*rs = find_next_bit(chunk->populated, end, *rs);
+	*re = find_next_zero_bit(chunk->populated, end, *rs + 1);
+}
+
+/*
+ * (Un)populated page region iterators.  Iterate over (un)populated
+ * page regions betwen @start and @end in @chunk.  @rs and @re should
+ * be integer variables and will be set to start and end page index of
+ * the current region.
+ */
+#define pcpu_for_each_unpop_region(chunk, rs, re, start, end)		    \
+	for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \
+	     (rs) < (re);						    \
+	     (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end)))
+
+#define pcpu_for_each_pop_region(chunk, rs, re, start, end)		    \
+	for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end));   \
+	     (rs) < (re);						    \
+	     (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end)))
+
 /**
  * pcpu_mem_alloc - allocate memory
  * @size: bytes to allocate
@@ -292,10 +330,10 @@ static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
  */
 static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
 {
-	void *first_start = pcpu_first_chunk->vm->addr;
+	void *first_start = pcpu_first_chunk->base_addr;
 
 	/* is it in the first chunk? */
-	if (addr >= first_start && addr < first_start + pcpu_chunk_size) {
+	if (addr >= first_start && addr < first_start + pcpu_unit_size) {
 		/* is it in the reserved area? */
 		if (addr < first_start + pcpu_reserved_chunk_limit)
 			return pcpu_reserved_chunk;
@@ -309,7 +347,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
 	 * space.  Note that any possible cpu id can be used here, so
 	 * there's no need to worry about preemption or cpu hotplug.
 	 */
-	addr += raw_smp_processor_id() * pcpu_unit_size;
+	addr += pcpu_unit_offsets[raw_smp_processor_id()];
 	return pcpu_get_page_chunk(vmalloc_to_page(addr));
 }
 
@@ -558,125 +596,327 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
 }
 
 /**
- * pcpu_unmap - unmap pages out of a pcpu_chunk
+ * pcpu_get_pages_and_bitmap - get temp pages array and bitmap
  * @chunk: chunk of interest
- * @page_start: page index of the first page to unmap
- * @page_end: page index of the last page to unmap + 1
- * @flush_tlb: whether to flush tlb or not
+ * @bitmapp: output parameter for bitmap
+ * @may_alloc: may allocate the array
  *
- * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.
- * If @flush is true, vcache is flushed before unmapping and tlb
- * after.
+ * Returns pointer to array of pointers to struct page and bitmap,
+ * both of which can be indexed with pcpu_page_idx().  The returned
+ * array is cleared to zero and *@bitmapp is copied from
+ * @chunk->populated.  Note that there is only one array and bitmap
+ * and access exclusion is the caller's responsibility.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc.
+ * Otherwise, don't care.
+ *
+ * RETURNS:
+ * Pointer to temp pages array on success, NULL on failure.
  */
-static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end,
-		       bool flush_tlb)
+static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk,
+					       unsigned long **bitmapp,
+					       bool may_alloc)
 {
-	unsigned int last = nr_cpu_ids - 1;
-	unsigned int cpu;
+	static struct page **pages;
+	static unsigned long *bitmap;
+	size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]);
+	size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) *
+			     sizeof(unsigned long);
+
+	if (!pages || !bitmap) {
+		if (may_alloc && !pages)
+			pages = pcpu_mem_alloc(pages_size);
+		if (may_alloc && !bitmap)
+			bitmap = pcpu_mem_alloc(bitmap_size);
+		if (!pages || !bitmap)
+			return NULL;
+	}
 
-	/* unmap must not be done on immutable chunk */
-	WARN_ON(chunk->immutable);
+	memset(pages, 0, pages_size);
+	bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages);
 
-	/*
-	 * Each flushing trial can be very expensive, issue flush on
-	 * the whole region at once rather than doing it for each cpu.
-	 * This could be an overkill but is more scalable.
-	 */
-	flush_cache_vunmap(pcpu_chunk_addr(chunk, 0, page_start),
-			   pcpu_chunk_addr(chunk, last, page_end));
+	*bitmapp = bitmap;
+	return pages;
+}
 
-	for_each_possible_cpu(cpu)
-		unmap_kernel_range_noflush(
-				pcpu_chunk_addr(chunk, cpu, page_start),
-				(page_end - page_start) << PAGE_SHIFT);
-
-	/* ditto as flush_cache_vunmap() */
-	if (flush_tlb)
-		flush_tlb_kernel_range(pcpu_chunk_addr(chunk, 0, page_start),
-				       pcpu_chunk_addr(chunk, last, page_end));
+/**
+ * pcpu_free_pages - free pages which were allocated for @chunk
+ * @chunk: chunk pages were allocated for
+ * @pages: array of pages to be freed, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be freed
+ * @page_end: page index of the last page to be freed + 1
+ *
+ * Free pages [@page_start and @page_end) in @pages for all units.
+ * The pages were allocated for @chunk.
+ */
+static void pcpu_free_pages(struct pcpu_chunk *chunk,
+			    struct page **pages, unsigned long *populated,
+			    int page_start, int page_end)
+{
+	unsigned int cpu;
+	int i;
+
+	for_each_possible_cpu(cpu) {
+		for (i = page_start; i < page_end; i++) {
+			struct page *page = pages[pcpu_page_idx(cpu, i)];
+
+			if (page)
+				__free_page(page);
+		}
+	}
 }
 
 /**
- * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
- * @chunk: chunk to depopulate
- * @off: offset to the area to depopulate
- * @size: size of the area to depopulate in bytes
- * @flush: whether to flush cache and tlb or not
- *
- * For each cpu, depopulate and unmap pages [@page_start,@page_end)
- * from @chunk.  If @flush is true, vcache is flushed before unmapping
- * and tlb after.
- *
- * CONTEXT:
- * pcpu_alloc_mutex.
+ * pcpu_alloc_pages - allocates pages for @chunk
+ * @chunk: target chunk
+ * @pages: array to put the allocated pages into, indexed by pcpu_page_idx()
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to be allocated
+ * @page_end: page index of the last page to be allocated + 1
+ *
+ * Allocate pages [@page_start,@page_end) into @pages for all units.
+ * The allocation is for @chunk.  Percpu core doesn't care about the
+ * content of @pages and will pass it verbatim to pcpu_map_pages().
  */
-static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size,
-				  bool flush)
+static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
+			    struct page **pages, unsigned long *populated,
+			    int page_start, int page_end)
 {
-	int page_start = PFN_DOWN(off);
-	int page_end = PFN_UP(off + size);
-	int unmap_start = -1;
-	int uninitialized_var(unmap_end);
+	const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
 	unsigned int cpu;
 	int i;
 
-	for (i = page_start; i < page_end; i++) {
-		for_each_possible_cpu(cpu) {
-			struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i);
+	for_each_possible_cpu(cpu) {
+		for (i = page_start; i < page_end; i++) {
+			struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
+
+			*pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
+			if (!*pagep) {
+				pcpu_free_pages(chunk, pages, populated,
+						page_start, page_end);
+				return -ENOMEM;
+			}
+		}
+	}
+	return 0;
+}
 
-			if (!*pagep)
-				continue;
+/**
+ * pcpu_pre_unmap_flush - flush cache prior to unmapping
+ * @chunk: chunk the regions to be flushed belongs to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages in [@page_start,@page_end) of @chunk are about to be
+ * unmapped.  Flush cache.  As each flushing trial can be very
+ * expensive, issue flush on the whole region at once rather than
+ * doing it for each cpu.  This could be an overkill but is more
+ * scalable.
+ */
+static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk,
+				 int page_start, int page_end)
+{
+	flush_cache_vunmap(
+		pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+		pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
+
+static void __pcpu_unmap_pages(unsigned long addr, int nr_pages)
+{
+	unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT);
+}
 
-			__free_page(*pagep);
+/**
+ * pcpu_unmap_pages - unmap pages out of a pcpu_chunk
+ * @chunk: chunk of interest
+ * @pages: pages array which can be used to pass information to free
+ * @populated: populated bitmap
+ * @page_start: page index of the first page to unmap
+ * @page_end: page index of the last page to unmap + 1
+ *
+ * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.
+ * Corresponding elements in @pages were cleared by the caller and can
+ * be used to carry information to pcpu_free_pages() which will be
+ * called after all unmaps are finished.  The caller should call
+ * proper pre/post flush functions.
+ */
+static void pcpu_unmap_pages(struct pcpu_chunk *chunk,
+			     struct page **pages, unsigned long *populated,
+			     int page_start, int page_end)
+{
+	unsigned int cpu;
+	int i;
 
-			/*
-			 * If it's partial depopulation, it might get
-			 * populated or depopulated again.  Mark the
-			 * page gone.
-			 */
-			*pagep = NULL;
+	for_each_possible_cpu(cpu) {
+		for (i = page_start; i < page_end; i++) {
+			struct page *page;
 
-			unmap_start = unmap_start < 0 ? i : unmap_start;
-			unmap_end = i + 1;
+			page = pcpu_chunk_page(chunk, cpu, i);
+			WARN_ON(!page);
+			pages[pcpu_page_idx(cpu, i)] = page;
 		}
+		__pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+				   page_end - page_start);
 	}
 
-	if (unmap_start >= 0)
-		pcpu_unmap(chunk, unmap_start, unmap_end, flush);
+	for (i = page_start; i < page_end; i++)
+		__clear_bit(i, populated);
+}
+
+/**
+ * pcpu_post_unmap_tlb_flush - flush TLB after unmapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been unmapped.  Flush
+ * TLB for the regions.  This can be skipped if the area is to be
+ * returned to vmalloc as vmalloc will handle TLB flushing lazily.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk,
+				      int page_start, int page_end)
+{
+	flush_tlb_kernel_range(
+		pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+		pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
+
+static int __pcpu_map_pages(unsigned long addr, struct page **pages,
+			    int nr_pages)
+{
+	return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,
+					PAGE_KERNEL, pages);
 }
 
 /**
- * pcpu_map - map pages into a pcpu_chunk
+ * pcpu_map_pages - map pages into a pcpu_chunk
  * @chunk: chunk of interest
+ * @pages: pages array containing pages to be mapped
+ * @populated: populated bitmap
  * @page_start: page index of the first page to map
  * @page_end: page index of the last page to map + 1
  *
- * For each cpu, map pages [@page_start,@page_end) into @chunk.
- * vcache is flushed afterwards.
+ * For each cpu, map pages [@page_start,@page_end) into @chunk.  The
+ * caller is responsible for calling pcpu_post_map_flush() after all
+ * mappings are complete.
+ *
+ * This function is responsible for setting corresponding bits in
+ * @chunk->populated bitmap and whatever is necessary for reverse
+ * lookup (addr -> chunk).
  */
-static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
+static int pcpu_map_pages(struct pcpu_chunk *chunk,
+			  struct page **pages, unsigned long *populated,
+			  int page_start, int page_end)
 {
-	unsigned int last = nr_cpu_ids - 1;
-	unsigned int cpu;
-	int err;
-
-	/* map must not be done on immutable chunk */
-	WARN_ON(chunk->immutable);
+	unsigned int cpu, tcpu;
+	int i, err;
 
 	for_each_possible_cpu(cpu) {
-		err = map_kernel_range_noflush(
-				pcpu_chunk_addr(chunk, cpu, page_start),
-				(page_end - page_start) << PAGE_SHIFT,
-				PAGE_KERNEL,
-				pcpu_chunk_pagep(chunk, cpu, page_start));
+		err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start),
+				       &pages[pcpu_page_idx(cpu, page_start)],
+				       page_end - page_start);
 		if (err < 0)
-			return err;
+			goto err;
+	}
+
+	/* mapping successful, link chunk and mark populated */
+	for (i = page_start; i < page_end; i++) {
+		for_each_possible_cpu(cpu)
+			pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)],
+					    chunk);
+		__set_bit(i, populated);
 	}
 
-	/* flush at once, please read comments in pcpu_unmap() */
-	flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start),
-			 pcpu_chunk_addr(chunk, last, page_end));
 	return 0;
+
+err:
+	for_each_possible_cpu(tcpu) {
+		if (tcpu == cpu)
+			break;
+		__pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start),
+				   page_end - page_start);
+	}
+	return err;
+}
+
+/**
+ * pcpu_post_map_flush - flush cache after mapping
+ * @chunk: pcpu_chunk the regions to be flushed belong to
+ * @page_start: page index of the first page to be flushed
+ * @page_end: page index of the last page to be flushed + 1
+ *
+ * Pages [@page_start,@page_end) of @chunk have been mapped.  Flush
+ * cache.
+ *
+ * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once
+ * for the whole region.
+ */
+static void pcpu_post_map_flush(struct pcpu_chunk *chunk,
+				int page_start, int page_end)
+{
+	flush_cache_vmap(
+		pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start),
+		pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end));
+}
+
+/**
+ * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
+ * @chunk: chunk to depopulate
+ * @off: offset to the area to depopulate
+ * @size: size of the area to depopulate in bytes
+ * @flush: whether to flush cache and tlb or not
+ *
+ * For each cpu, depopulate and unmap pages [@page_start,@page_end)
+ * from @chunk.  If @flush is true, vcache is flushed before unmapping
+ * and tlb after.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex.
+ */
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+	int page_start = PFN_DOWN(off);
+	int page_end = PFN_UP(off + size);
+	struct page **pages;
+	unsigned long *populated;
+	int rs, re;
+
+	/* quick path, check whether it's empty already */
+	pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+		if (rs == page_start && re == page_end)
+			return;
+		break;
+	}
+
+	/* immutable chunks can't be depopulated */
+	WARN_ON(chunk->immutable);
+
+	/*
+	 * If control reaches here, there must have been at least one
+	 * successful population attempt so the temp pages array must
+	 * be available now.
+	 */
+	pages = pcpu_get_pages_and_bitmap(chunk, &populated, false);
+	BUG_ON(!pages);
+
+	/* unmap and free */
+	pcpu_pre_unmap_flush(chunk, page_start, page_end);
+
+	pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+		pcpu_unmap_pages(chunk, pages, populated, rs, re);
+
+	/* no need to flush tlb, vmalloc will handle it lazily */
+
+	pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
+		pcpu_free_pages(chunk, pages, populated, rs, re);
+
+	/* commit new bitmap */
+	bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
 }
 
 /**
@@ -693,58 +933,68 @@ static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)
  */
 static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
 {
-	const gfp_t alloc_mask = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
 	int page_start = PFN_DOWN(off);
 	int page_end = PFN_UP(off + size);
-	int map_start = -1;
-	int uninitialized_var(map_end);
+	int free_end = page_start, unmap_end = page_start;
+	struct page **pages;
+	unsigned long *populated;
 	unsigned int cpu;
-	int i;
+	int rs, re, rc;
 
-	for (i = page_start; i < page_end; i++) {
-		if (pcpu_chunk_page_occupied(chunk, i)) {
-			if (map_start >= 0) {
-				if (pcpu_map(chunk, map_start, map_end))
-					goto err;
-				map_start = -1;
-			}
-			continue;
-		}
+	/* quick path, check whether all pages are already there */
+	pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) {
+		if (rs == page_start && re == page_end)
+			goto clear;
+		break;
+	}
 
-		map_start = map_start < 0 ? i : map_start;
-		map_end = i + 1;
+	/* need to allocate and map pages, this chunk can't be immutable */
+	WARN_ON(chunk->immutable);
 
-		for_each_possible_cpu(cpu) {
-			struct page **pagep = pcpu_chunk_pagep(chunk, cpu, i);
+	pages = pcpu_get_pages_and_bitmap(chunk, &populated, true);
+	if (!pages)
+		return -ENOMEM;
 
-			*pagep = alloc_pages_node(cpu_to_node(cpu),
-						  alloc_mask, 0);
-			if (!*pagep)
-				goto err;
-			pcpu_set_page_chunk(*pagep, chunk);
-		}
+	/* alloc and map */
+	pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+		rc = pcpu_alloc_pages(chunk, pages, populated, rs, re);
+		if (rc)
+			goto err_free;
+		free_end = re;
 	}
 
-	if (map_start >= 0 && pcpu_map(chunk, map_start, map_end))
-		goto err;
+	pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) {
+		rc = pcpu_map_pages(chunk, pages, populated, rs, re);
+		if (rc)
+			goto err_unmap;
+		unmap_end = re;
+	}
+	pcpu_post_map_flush(chunk, page_start, page_end);
 
+	/* commit new bitmap */
+	bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
+clear:
 	for_each_possible_cpu(cpu)
-		memset(chunk->vm->addr + cpu * pcpu_unit_size + off, 0,
-		       size);
-
+		memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
 	return 0;
-err:
-	/* likely under heavy memory pressure, give memory back */
-	pcpu_depopulate_chunk(chunk, off, size, true);
-	return -ENOMEM;
+
+err_unmap:
+	pcpu_pre_unmap_flush(chunk, page_start, unmap_end);
+	pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end)
+		pcpu_unmap_pages(chunk, pages, populated, rs, re);
+	pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end);
+err_free:
+	pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end)
+		pcpu_free_pages(chunk, pages, populated, rs, re);
+	return rc;
 }
 
 static void free_pcpu_chunk(struct pcpu_chunk *chunk)
 {
 	if (!chunk)
 		return;
-	if (chunk->vm)
-		free_vm_area(chunk->vm);
+	if (chunk->vms)
+		pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups);
 	pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
 	kfree(chunk);
 }
@@ -760,10 +1010,11 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
 	chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
 	chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
 	chunk->map[chunk->map_used++] = pcpu_unit_size;
-	chunk->page = chunk->page_ar;
 
-	chunk->vm = get_vm_area(pcpu_chunk_size, VM_ALLOC);
-	if (!chunk->vm) {
+	chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+				       pcpu_nr_groups, pcpu_atom_size,
+				       GFP_KERNEL);
+	if (!chunk->vms) {
 		free_pcpu_chunk(chunk);
 		return NULL;
 	}
@@ -771,6 +1022,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
 	INIT_LIST_HEAD(&chunk->list);
 	chunk->free_size = pcpu_unit_size;
 	chunk->contig_hint = pcpu_unit_size;
+	chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0];
 
 	return chunk;
 }
@@ -860,7 +1112,8 @@ area_found:
 
 	mutex_unlock(&pcpu_alloc_mutex);
 
-	return __addr_to_pcpu_ptr(chunk->vm->addr + off);
+	/* return address relative to base address */
+	return __addr_to_pcpu_ptr(chunk->base_addr + off);
 
 fail_unlock:
 	spin_unlock_irq(&pcpu_lock);
@@ -938,12 +1191,13 @@ static void pcpu_reclaim(struct work_struct *work)
 	}
 
 	spin_unlock_irq(&pcpu_lock);
-	mutex_unlock(&pcpu_alloc_mutex);
 
 	list_for_each_entry_safe(chunk, next, &todo, list) {
-		pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
+		pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
 		free_pcpu_chunk(chunk);
 	}
+
+	mutex_unlock(&pcpu_alloc_mutex);
 }
 
 /**
@@ -968,7 +1222,7 @@ void free_percpu(void *ptr)
 	spin_lock_irqsave(&pcpu_lock, flags);
 
 	chunk = pcpu_chunk_addr_search(addr);
-	off = addr - chunk->vm->addr;
+	off = addr - chunk->base_addr;
 
 	pcpu_free_area(chunk, off);
 
@@ -987,30 +1241,295 @@ void free_percpu(void *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
+static inline size_t pcpu_calc_fc_sizes(size_t static_size,
+					size_t reserved_size,
+					ssize_t *dyn_sizep)
+{
+	size_t size_sum;
+
+	size_sum = PFN_ALIGN(static_size + reserved_size +
+			     (*dyn_sizep >= 0 ? *dyn_sizep : 0));
+	if (*dyn_sizep != 0)
+		*dyn_sizep = size_sum - static_size - reserved_size;
+
+	return size_sum;
+}
+
 /**
- * pcpu_setup_first_chunk - initialize the first percpu chunk
- * @get_page_fn: callback to fetch page pointer
- * @static_size: the size of static percpu area in bytes
+ * pcpu_alloc_alloc_info - allocate percpu allocation info
+ * @nr_groups: the number of groups
+ * @nr_units: the number of units
+ *
+ * Allocate ai which is large enough for @nr_groups groups containing
+ * @nr_units units.  The returned ai's groups[0].cpu_map points to the
+ * cpu_map array which is long enough for @nr_units and filled with
+ * NR_CPUS.  It's the caller's responsibility to initialize cpu_map
+ * pointer of other groups.
+ *
+ * RETURNS:
+ * Pointer to the allocated pcpu_alloc_info on success, NULL on
+ * failure.
+ */
+struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
+						      int nr_units)
+{
+	struct pcpu_alloc_info *ai;
+	size_t base_size, ai_size;
+	void *ptr;
+	int unit;
+
+	base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]),
+			  __alignof__(ai->groups[0].cpu_map[0]));
+	ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);
+
+	ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size));
+	if (!ptr)
+		return NULL;
+	ai = ptr;
+	ptr += base_size;
+
+	ai->groups[0].cpu_map = ptr;
+
+	for (unit = 0; unit < nr_