1 files changed, 48 insertions, 110 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 474e3683b74d..81462ce5866e 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -253,13 +253,13 @@ static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
 /* set the pointer to a chunk in a page struct */
 static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu)
 {
-	page->index = (unsigned long)pcpu;
+	page->private = (unsigned long)pcpu;
 }
 
 /* obtain pointer to a chunk from a page struct */
 static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page)
 {
-	return (struct pcpu_chunk *)page->index;
+	return (struct pcpu_chunk *)page->private;
 }
 
 static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx)
@@ -1359,10 +1359,7 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr,
 	/* allocate chunk */
 	alloc_size = struct_size(chunk, populated,
 				 BITS_TO_LONGS(region_size >> PAGE_SHIFT));
-	chunk = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!chunk)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	chunk = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	INIT_LIST_HEAD(&chunk->list);
 
@@ -1374,24 +1371,14 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr,
 	region_bits = pcpu_chunk_map_bits(chunk);
 
 	alloc_size = BITS_TO_LONGS(region_bits) * sizeof(chunk->alloc_map[0]);
-	chunk->alloc_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!chunk->alloc_map)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	chunk->alloc_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	alloc_size =
 		BITS_TO_LONGS(region_bits + 1) * sizeof(chunk->bound_map[0]);
-	chunk->bound_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!chunk->bound_map)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	chunk->bound_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	alloc_size = pcpu_chunk_nr_blocks(chunk) * sizeof(chunk->md_blocks[0]);
-	chunk->md_blocks = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!chunk->md_blocks)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
-
+	chunk->md_blocks = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 #ifdef NEED_PCPUOBJ_EXT
 	/* first chunk is free to use */
 	chunk->obj_exts = NULL;
@@ -1619,7 +1606,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
 	return pcpu_get_page_chunk(pcpu_addr_to_page(addr));
 }
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG
 static bool pcpu_memcg_pre_alloc_hook(size_t size, gfp_t gfp,
 				      struct obj_cgroup **objcgp)
 {
@@ -1681,7 +1668,7 @@ static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
 	obj_cgroup_put(objcg);
 }
 
-#else /* CONFIG_MEMCG_KMEM */
+#else /* CONFIG_MEMCG */
 static bool
 pcpu_memcg_pre_alloc_hook(size_t size, gfp_t gfp, struct obj_cgroup **objcgp)
 {
@@ -1697,7 +1684,7 @@ static void pcpu_memcg_post_alloc_hook(struct obj_cgroup *objcg,
 static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size)
 {
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG */
 
 #ifdef CONFIG_MEM_ALLOC_PROFILING
 static void pcpu_alloc_tag_alloc_hook(struct pcpu_chunk *chunk, int off,
@@ -1747,7 +1734,7 @@ void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved,
 	bool is_atomic;
 	bool do_warn;
 	struct obj_cgroup *objcg = NULL;
-	static int warn_limit = 10;
+	static atomic_t warn_limit = ATOMIC_INIT(10);
 	struct pcpu_chunk *chunk, *next;
 	const char *err;
 	int slot, off, cpu, ret;
@@ -1758,7 +1745,7 @@ void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved,
 	gfp = current_gfp_context(gfp);
 	/* whitelisted flags that can be passed to the backing allocators */
 	pcpu_gfp = gfp & (GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
-	is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL;
+	is_atomic = !gfpflags_allow_blocking(gfp);
 	do_warn = !(gfp & __GFP_NOWARN);
 
 	/*
@@ -1864,6 +1851,10 @@ restart:
 
 area_found:
 	pcpu_stats_area_alloc(chunk, size);
+
+	if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
+		pcpu_schedule_balance_work();
+
 	spin_unlock_irqrestore(&pcpu_lock, flags);
 
 	/* populate if not all pages are already there */
@@ -1891,9 +1882,6 @@ area_found:
 		mutex_unlock(&pcpu_alloc_mutex);
 	}
 
-	if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
-		pcpu_schedule_balance_work();
-
 	/* clear the areas and return address relative to base address */
 	for_each_possible_cpu(cpu)
 		memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
@@ -1916,13 +1904,17 @@ fail_unlock:
 fail:
 	trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align);
 
-	if (do_warn && warn_limit) {
-		pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n",
-			size, align, is_atomic, err);
-		if (!is_atomic)
-			dump_stack();
-		if (!--warn_limit)
-			pr_info("limit reached, disable warning\n");
+	if (do_warn) {
+		int remaining = atomic_dec_if_positive(&warn_limit);
+
+		if (remaining >= 0) {
+			pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n",
+				size, align, is_atomic, err);
+			if (!is_atomic)
+				dump_stack();
+			if (remaining == 0)
+				pr_info("limit reached, disable warning\n");
+		}
 	}
 
 	if (is_atomic) {
@@ -2203,7 +2195,12 @@ static void pcpu_balance_workfn(struct work_struct *work)
 	 * to grow other chunks.  This then gives pcpu_reclaim_populated() time
 	 * to move fully free chunks to the active list to be freed if
 	 * appropriate.
+	 *
+	 * Enforce GFP_NOIO allocations because we have pcpu_alloc users
+	 * constrained to GFP_NOIO/NOFS contexts and they could form lock
+	 * dependency through pcpu_alloc_mutex
 	 */
+	unsigned int flags = memalloc_noio_save();
 	mutex_lock(&pcpu_alloc_mutex);
 	spin_lock_irq(&pcpu_lock);
 
@@ -2214,37 +2211,7 @@ static void pcpu_balance_workfn(struct work_struct *work)
 
 	spin_unlock_irq(&pcpu_lock);
 	mutex_unlock(&pcpu_alloc_mutex);
-}
-
-/**
- * pcpu_alloc_size - the size of the dynamic percpu area
- * @ptr: pointer to the dynamic percpu area
- *
- * Returns the size of the @ptr allocation.  This is undefined for statically
- * defined percpu variables as there is no corresponding chunk->bound_map.
- *
- * RETURNS:
- * The size of the dynamic percpu area.
- *
- * CONTEXT:
- * Can be called from atomic context.
- */
-size_t pcpu_alloc_size(void __percpu *ptr)
-{
-	struct pcpu_chunk *chunk;
-	unsigned long bit_off, end;
-	void *addr;
-
-	if (!ptr)
-		return 0;
-
-	addr = __pcpu_ptr_to_addr(ptr);
-	/* No pcpu_lock here: ptr has not been freed, so chunk is still alive */
-	chunk = pcpu_chunk_addr_search(addr);
-	bit_off = (addr - chunk->base_addr) / PCPU_MIN_ALLOC_SIZE;
-	end = find_next_bit(chunk->bound_map, pcpu_chunk_map_bits(chunk),
-			    bit_off + 1);
-	return (end - bit_off) * PCPU_MIN_ALLOC_SIZE;
+	memalloc_noio_restore(flags);
 }
 
 /**
@@ -2625,28 +2592,16 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 
 	/* process group information and build config tables accordingly */
 	alloc_size = ai->nr_groups * sizeof(group_offsets[0]);
-	group_offsets = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!group_offsets)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	group_offsets = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	alloc_size = ai->nr_groups * sizeof(group_sizes[0]);
-	group_sizes = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!group_sizes)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	group_sizes = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	alloc_size = nr_cpu_ids * sizeof(unit_map[0]);
-	unit_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!unit_map)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	unit_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	alloc_size = nr_cpu_ids * sizeof(unit_off[0]);
-	unit_off = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
-	if (!unit_off)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      alloc_size);
+	unit_off = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES);
 
 	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
 		unit_map[cpu] = UINT_MAX;
@@ -2715,12 +2670,9 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 	pcpu_free_slot = pcpu_sidelined_slot + 1;
 	pcpu_to_depopulate_slot = pcpu_free_slot + 1;
 	pcpu_nr_slots = pcpu_to_depopulate_slot + 1;
-	pcpu_chunk_lists = memblock_alloc(pcpu_nr_slots *
+	pcpu_chunk_lists = memblock_alloc_or_panic(pcpu_nr_slots *
 					  sizeof(pcpu_chunk_lists[0]),
 					  SMP_CACHE_BYTES);
-	if (!pcpu_chunk_lists)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      pcpu_nr_slots * sizeof(pcpu_chunk_lists[0]));
 
 	for (i = 0; i < pcpu_nr_slots; i++)
 		INIT_LIST_HEAD(&pcpu_chunk_lists[i]);
@@ -3129,7 +3081,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
 				continue;
 			}
 			/* copy and return the unused part */
-			memcpy(ptr, __per_cpu_load, ai->static_size);
+			memcpy(ptr, __per_cpu_start, ai->static_size);
 			pcpu_fc_free(ptr + size_sum, ai->unit_size - size_sum);
 		}
 	}
@@ -3160,7 +3112,7 @@ out_free:
 #endif /* BUILD_EMBED_FIRST_CHUNK */
 
 #ifdef BUILD_PAGE_FIRST_CHUNK
-#include <asm/pgalloc.h>
+#include <linux/pgalloc.h>
 
 #ifndef P4D_TABLE_SIZE
 #define P4D_TABLE_SIZE PAGE_SIZE
@@ -3185,25 +3137,19 @@ void __init __weak pcpu_populate_pte(unsigned long addr)
 	pmd_t *pmd;
 
 	if (pgd_none(*pgd)) {
-		p4d = memblock_alloc(P4D_TABLE_SIZE, P4D_TABLE_SIZE);
-		if (!p4d)
-			goto err_alloc;
-		pgd_populate(&init_mm, pgd, p4d);
+		p4d = memblock_alloc_or_panic(P4D_TABLE_SIZE, P4D_TABLE_SIZE);
+		pgd_populate_kernel(addr, pgd, p4d);
 	}
 
 	p4d = p4d_offset(pgd, addr);
 	if (p4d_none(*p4d)) {
-		pud = memblock_alloc(PUD_TABLE_SIZE, PUD_TABLE_SIZE);
-		if (!pud)
-			goto err_alloc;
-		p4d_populate(&init_mm, p4d, pud);
+		pud = memblock_alloc_or_panic(PUD_TABLE_SIZE, PUD_TABLE_SIZE);
+		p4d_populate_kernel(addr, p4d, pud);
 	}
 
 	pud = pud_offset(p4d, addr);
 	if (pud_none(*pud)) {
-		pmd = memblock_alloc(PMD_TABLE_SIZE, PMD_TABLE_SIZE);
-		if (!pmd)
-			goto err_alloc;
+		pmd = memblock_alloc_or_panic(PMD_TABLE_SIZE, PMD_TABLE_SIZE);
 		pud_populate(&init_mm, pud, pmd);
 	}
 
@@ -3211,16 +3157,11 @@ void __init __weak pcpu_populate_pte(unsigned long addr)
 	if (!pmd_present(*pmd)) {
 		pte_t *new;
 
-		new = memblock_alloc(PTE_TABLE_SIZE, PTE_TABLE_SIZE);
-		if (!new)
-			goto err_alloc;
+		new = memblock_alloc_or_panic(PTE_TABLE_SIZE, PTE_TABLE_SIZE);
 		pmd_populate_kernel(&init_mm, pmd, new);
 	}
 
 	return;
-
-err_alloc:
-	panic("%s: Failed to allocate memory\n", __func__);
 }
 
 /**
@@ -3267,10 +3208,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, pcpu_fc_cpu_to_node_fn_t
 	/* unaligned allocations can't be freed, round up to page size */
 	pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
 			       sizeof(pages[0]));
-	pages = memblock_alloc(pages_size, SMP_CACHE_BYTES);
-	if (!pages)
-		panic("%s: Failed to allocate %zu bytes\n", __func__,
-		      pages_size);
+	pages = memblock_alloc_or_panic(pages_size, SMP_CACHE_BYTES);
 
 	/* allocate pages */
 	j = 0;
@@ -3312,7 +3250,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, pcpu_fc_cpu_to_node_fn_t
 		flush_cache_vmap_early(unit_addr, unit_addr + ai->unit_size);
 
 		/* copy static data */
-		memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
+		memcpy((void *)unit_addr, __per_cpu_start, ai->static_size);
 	}
 
 	/* we're ready, commit */
@@ -3421,7 +3359,7 @@ void __init setup_per_cpu_areas(void)
  */
 unsigned long pcpu_nr_pages(void)
 {
-	return pcpu_nr_populated * pcpu_nr_units;
+	return data_race(READ_ONCE(pcpu_nr_populated)) * pcpu_nr_units;
 }
 
 /*