* [PATCH 4/5] percpu: move vmalloc based chunk management into percpu-vm.c
2010-04-08 4:11 percpu: implement nommu support Tejun Heo
` (2 preceding siblings ...)
2010-04-08 4:11 ` [PATCH 3/5] percpu: misc preparations for nommu support Tejun Heo
@ 2010-04-08 4:11 ` Tejun Heo
2010-04-08 4:11 ` [PATCH 5/5] percpu: implement kernel memory based chunk allocation Tejun Heo
2010-04-08 14:06 ` percpu: implement nommu support David Howells
5 siblings, 0 replies; 9+ messages in thread
From: Tejun Heo @ 2010-04-08 4:11 UTC (permalink / raw)
To: linux-kernel, graff.yang, dhowells, akpm, uclinux-dist-devel,
sonic.adi, cl, mingo
Cc: Tejun Heo
Separate out and move chunk management (creation/desctruction and
[de]population) code into percpu-vm.c which is included by percpu.c
and compiled together. The interface for chunk management is defined
as follows.
* pcpu_populate_chunk - populate the specified range of a chunk
* pcpu_depopulate_chunk - depopulate the specified range of a chunk
* pcpu_create_chunk - create a new chunk
* pcpu_destroy_chunk - destroy a chunk, always preceded by full depop
* pcpu_addr_to_page - translate address to physical address
* pcpu_verify_alloc_info - check alloc_info is acceptable during init
Other than wrapping vmalloc_to_page() inside pcpu_addr_to_page() and
dummy pcpu_verify_alloc_info() implementation, this patch only moves
code around. This separation is to allow alternate chunk management
implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>
Cc: David Howells <dhowells@redhat.com>
---
mm/percpu-vm.c | 451 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
mm/percpu.c | 452 +++-----------------------------------------------------
2 files changed, 475 insertions(+), 428 deletions(-)
create mode 100644 mm/percpu-vm.c
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
new file mode 100644
index 0000000..7d9c1d0
--- /dev/null
+++ b/mm/percpu-vm.c
@@ -0,0 +1,451 @@
+/*
+ * mm/percpu-vm.c - vmalloc area based chunk allocation
+ *
+ * Copyright (C) 2010 SUSE Linux Products GmbH
+ * Copyright (C) 2010 Tejun Heo <tj@kernel.org>
+ *
+ * This file is released under the GPLv2.
+ *
+ * Chunks are mapped into vmalloc areas and populated page by page.
+ * This is the default chunk allocator.
+ */
+
+static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
+ unsigned int cpu, int page_idx)
+{
+ /* must not be used on pre-mapped chunk */
+ WARN_ON(chunk->immutable);
+
+ return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx));
+}
+
+/**
+ * pcpu_get_pages_and_bitmap - get temp pages array and bitmap
+ * @chunk: chunk of interest
+ * @bitmapp: output parameter for bitmap
+ * @may_alloc: may allocate the array
+ *
+ * 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 struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk,
+ unsigned long **bitmapp,
+ bool may_alloc)
+{
+ 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;
+ }
+
+ memset(pages, 0, pages_size);
+ bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages);
+
+ *bitmapp = bitmap;
+ return pages;
+}
+
+/**
+ * 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_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 int pcpu_alloc_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
+ unsigned int cpu;
+ int 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;
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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;
+
+ for_each_possible_cpu(cpu) {
+ for (i = page_start; i < page_end; i++) {
+ struct page *page;
+
+ 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);
+ }
+
+ 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_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. 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_pages(struct pcpu_chunk *chunk,
+ struct page **pages, unsigned long *populated,
+ int page_start, int page_end)
+{
+ unsigned int cpu, tcpu;
+ int i, err;
+
+ for_each_possible_cpu(cpu) {
+ 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)
+ 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);
+ }
+
+ 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_populate_chunk - populate and map an area of a pcpu_chunk
+ * @chunk: chunk of interest
+ * @off: offset to the area to populate
+ * @size: size of the area to populate in bytes
+ *
+ * For each cpu, populate and map pages [@page_start,@page_end) into
+ * @chunk. The area is cleared on return.
+ *
+ * CONTEXT:
+ * pcpu_alloc_mutex, does GFP_KERNEL allocation.
+ */
+static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
+{
+ int page_start = PFN_DOWN(off);
+ int page_end = PFN_UP(off + size);
+ int free_end = page_start, unmap_end = page_start;
+ struct page **pages;
+ unsigned long *populated;
+ unsigned int cpu;
+ int rs, re, rc;
+
+ /* quick path, check whether all pages are already there */
+ rs = page_start;
+ pcpu_next_pop(chunk, &rs, &re, page_end);
+ if (rs == page_start && re == page_end)
+ goto clear;
+
+ /* need to allocate and map pages, this chunk can't be immutable */
+ WARN_ON(chunk->immutable);
+
+ pages = pcpu_get_pages_and_bitmap(chunk, &populated, true);
+ if (!pages)
+ return -ENOMEM;
+
+ /* 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;
+ }
+
+ 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((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
+ return 0;
+
+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;
+}
+
+/**
+ * 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 */
+ rs = page_start;
+ pcpu_next_unpop(chunk, &rs, &re, page_end);
+ if (rs == page_start && re == page_end)
+ return;
+
+ /* 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);
+}
+
+static struct pcpu_chunk *pcpu_create_chunk(void)
+{
+ struct pcpu_chunk *chunk;
+ struct vm_struct **vms;
+
+ chunk = pcpu_alloc_chunk();
+ if (!chunk)
+ return NULL;
+
+ vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+ pcpu_nr_groups, pcpu_atom_size, GFP_KERNEL);
+ if (!vms) {
+ pcpu_free_chunk(chunk);
+ return NULL;
+ }
+
+ chunk->data = vms;
+ chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
+ return chunk;
+}
+
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
+{
+ if (chunk && chunk->data)
+ pcpu_free_vm_areas(chunk->data, pcpu_nr_groups);
+ pcpu_free_chunk(chunk);
+}
+
+static struct page *pcpu_addr_to_page(void *addr)
+{
+ return vmalloc_to_page(addr);
+}
+
+static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai)
+{
+ /* no extra restriction */
+ return 0;
+}
diff --git a/mm/percpu.c b/mm/percpu.c
index 5bfe4d7..4c5b074 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -236,15 +236,6 @@ static unsigned long __maybe_unused pcpu_chunk_addr(struct pcpu_chunk *chunk,
(page_idx << PAGE_SHIFT);
}
-static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
- unsigned int cpu, int page_idx)
-{
- /* must not be used on pre-mapped chunk */
- WARN_ON(chunk->immutable);
-
- return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx));
-}
-
static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk,
int *rs, int *re, int end)
{
@@ -636,425 +627,29 @@ static void pcpu_free_chunk(struct pcpu_chunk *chunk)
kfree(chunk);
}
-/**
- * pcpu_get_pages_and_bitmap - get temp pages array and bitmap
- * @chunk: chunk of interest
- * @bitmapp: output parameter for bitmap
- * @may_alloc: may allocate the array
- *
- * 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 struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk,
- unsigned long **bitmapp,
- bool may_alloc)
-{
- 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;
- }
-
- memset(pages, 0, pages_size);
- bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages);
-
- *bitmapp = bitmap;
- return pages;
-}
-
-/**
- * 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_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 int pcpu_alloc_pages(struct pcpu_chunk *chunk,
- struct page **pages, unsigned long *populated,
- int page_start, int page_end)
-{
- const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
- unsigned int cpu;
- int 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;
-}
-
-/**
- * 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);
-}
-
-/**
- * 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;
-
- for_each_possible_cpu(cpu) {
- for (i = page_start; i < page_end; i++) {
- struct page *page;
-
- 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);
- }
-
- 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_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. 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_pages(struct pcpu_chunk *chunk,
- struct page **pages, unsigned long *populated,
- int page_start, int page_end)
-{
- unsigned int cpu, tcpu;
- int i, err;
-
- for_each_possible_cpu(cpu) {
- 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)
- 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);
- }
-
- 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 */
- rs = page_start;
- pcpu_next_unpop(chunk, &rs, &re, page_end);
- if (rs == page_start && re == page_end)
- return;
-
- /* 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);
-}
-
-/**
- * pcpu_populate_chunk - populate and map an area of a pcpu_chunk
- * @chunk: chunk of interest
- * @off: offset to the area to populate
- * @size: size of the area to populate in bytes
- *
- * For each cpu, populate and map pages [@page_start,@page_end) into
- * @chunk. The area is cleared on return.
- *
- * CONTEXT:
- * pcpu_alloc_mutex, does GFP_KERNEL allocation.
+/*
+ * Chunk management implementation.
+ *
+ * To allow different implementations, chunk alloc/free and
+ * [de]population are implemented in a separate file which is pulled
+ * into this file and compiled together. The following functions
+ * should be implemented.
+ *
+ * pcpu_populate_chunk - populate the specified range of a chunk
+ * pcpu_depopulate_chunk - depopulate the specified range of a chunk
+ * pcpu_create_chunk - create a new chunk
+ * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop
+ * pcpu_addr_to_page - translate address to physical address
+ * pcpu_verify_alloc_info - check alloc_info is acceptable during init
*/
-static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
-{
- int page_start = PFN_DOWN(off);
- int page_end = PFN_UP(off + size);
- int free_end = page_start, unmap_end = page_start;
- struct page **pages;
- unsigned long *populated;
- unsigned int cpu;
- int rs, re, rc;
-
- /* quick path, check whether all pages are already there */
- rs = page_start;
- pcpu_next_pop(chunk, &rs, &re, page_end);
- if (rs == page_start && re == page_end)
- goto clear;
-
- /* need to allocate and map pages, this chunk can't be immutable */
- WARN_ON(chunk->immutable);
-
- pages = pcpu_get_pages_and_bitmap(chunk, &populated, true);
- if (!pages)
- return -ENOMEM;
-
- /* 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;
- }
-
- 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((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
- return 0;
-
-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 int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size);
+static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size);
+static struct pcpu_chunk *pcpu_create_chunk(void);
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk);
+static struct page *pcpu_addr_to_page(void *addr);
+static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai);
-static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
-{
- if (chunk && chunk->data)
- pcpu_free_vm_areas(chunk->data, pcpu_nr_groups);
- pcpu_free_chunk(chunk);
-}
-
-static struct pcpu_chunk *pcpu_create_chunk(void)
-{
- struct pcpu_chunk *chunk;
- struct vm_struct **vms;
-
- chunk = pcpu_alloc_chunk();
- if (!chunk)
- return NULL;
-
- vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
- pcpu_nr_groups, pcpu_atom_size, GFP_KERNEL);
- if (!vms) {
- pcpu_free_chunk(chunk);
- return NULL;
- }
-
- chunk->data = vms;
- chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
- return chunk;
-}
+#include "percpu-vm.c"
/**
* pcpu_chunk_addr_search - determine chunk containing specified address
@@ -1081,7 +676,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
* there's no need to worry about preemption or cpu hotplug.
*/
addr += pcpu_unit_offsets[raw_smp_processor_id()];
- return pcpu_get_page_chunk(vmalloc_to_page(addr));
+ return pcpu_get_page_chunk(pcpu_addr_to_page(addr));
}
/**
@@ -1381,7 +976,7 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
else
return page_to_phys(vmalloc_to_page(addr));
} else
- return page_to_phys(vmalloc_to_page(addr));
+ return page_to_phys(pcpu_addr_to_page(addr));
}
static inline size_t pcpu_calc_fc_sizes(size_t static_size,
@@ -1753,6 +1348,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
+ PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);
/* process group information and build config tables accordingly */
group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
--
1.6.4.2
^ permalink raw reply related [flat|nested] 9+ messages in thread