This nvm pages allocator will implement the simple buddy to manage the
nvm address space. This patch initializes this buddy for new namespace.
the unit of alloc/free of the buddy is page. DAX device has their
struct page(in dram or PMEM).
struct { /* ZONE_DEVICE pages */
/** @pgmap: Points to the hosting device page map. */
struct dev_pagemap *pgmap;
void *zone_device_data;
/*
* ZONE_DEVICE private pages are counted as being
* mapped so the next 3 words hold the mapping, index,
* and private fields from the source anonymous or
* page cache page while the page is migrated to device
* private memory.
* ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
* use the mapping, index, and private fields when
* pmem backed DAX files are mapped.
*/
};
ZONE_DEVICE pages only use pgmap. Other 4 words[16/32 bytes] don't use.
So the second/third word will be used as 'struct list_head ' which list
in buddy. The fourth word(that is normal struct page::index) store pgoff
which the page-offset in the dax device. And the fifth word (that is
normal struct page::private) store order of buddy. page_type will be used
to store buddy flags.
Signed-off-by: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
---
drivers/md/bcache/nvm-pages.c | 82 +++++++++++++++++++++++++++++++++--
drivers/md/bcache/nvm-pages.h | 3 ++
2 files changed, 82 insertions(+), 3 deletions(-)
diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
index 29ee4dbc504d..ea36994b5b00 100644
--- a/drivers/md/bcache/nvm-pages.c
+++ b/drivers/md/bcache/nvm-pages.c
@@ -74,8 +74,10 @@ static void release_nvm_namespaces(struct bch_nvm_set *nvm_set)
{
int i;
- for (i = 0; i < nvm_set->total_namespaces_nr; i++)
+ for (i = 0; i < nvm_set->total_namespaces_nr; i++) {
+ kfree(nvm_set->nss[i]->pages_bitmap);
kfree(nvm_set->nss[i]);
+ }
kfree(nvm_set->nss);
}
@@ -92,6 +94,17 @@ static void *nvm_pgoff_to_vaddr(struct bch_nvm_namespace *ns, pgoff_t pgoff)
return ns->kaddr + ns->pages_offset + (pgoff << PAGE_SHIFT);
}
+static struct page *nvm_vaddr_to_page(struct bch_nvm_namespace *ns, void *addr)
+{
+ return virt_to_page(addr);
+}
+
+static inline void remove_owner_space(struct bch_nvm_namespace *ns,
+ pgoff_t pgoff, u32 nr)
+{
+ bitmap_set(ns->pages_bitmap, pgoff, nr);
+}
+
static int init_owner_info(struct bch_nvm_namespace *ns)
{
struct owner_list_head *owner_list_head;
@@ -146,6 +159,8 @@ static int init_owner_info(struct bch_nvm_namespace *ns)
extent->kaddr = nvm_pgoff_to_vaddr(extents->ns, rec->pgoff);
extent->nr = rec->nr;
list_add_tail(&extent->list, &extents->extent_head);
+ /*remove already alloced space*/
+ remove_owner_space(extents->ns, rec->pgoff, rec->nr);
extents->ns->free -= rec->nr;
}
@@ -166,6 +181,54 @@ static int init_owner_info(struct bch_nvm_namespace *ns)
return 0;
}
+static void init_nvm_free_space(struct bch_nvm_namespace *ns)
+{
+ unsigned int start, end, i;
+ struct page *page;
+ unsigned int pages;
+ pgoff_t pgoff_start;
+
+ bitmap_for_each_clear_region(ns->pages_bitmap, start, end, 0, ns->pages_total) {
+ pgoff_start = start;
+ pages = end - start;
+
+ while (pages) {
+ for (i = MAX_ORDER - 1; i >= 0 ; i--) {
+ if ((start % (1 << i) == 0) && (pages >= (1 << i)))
+ break;
+ }
+
+ page = nvm_vaddr_to_page(ns, nvm_pgoff_to_vaddr(ns, pgoff_start));
+ page->index = pgoff_start;
+ set_page_private(page, i);
+ __SetPageBuddy(page);
+ list_add((struct list_head *)&page->zone_device_data, &ns->free_area[i]);
+
+ pgoff_start += 1 << i;
+ pages -= 1 << i;
+ }
+ }
+
+ bitmap_for_each_set_region(ns->pages_bitmap, start, end, 0, ns->pages_total) {
+ pages = end - start;
+ pgoff_start = start;
+
+ while (pages) {
+ for (i = MAX_ORDER - 1; i >= 0 ; i--) {
+ if ((start % (1 << i) == 0) && (pages >= (1 << i)))
+ break;
+ }
+
+ page = nvm_vaddr_to_page(ns, nvm_pgoff_to_vaddr(ns, pgoff_start));
+ page->index = pgoff_start;
+ page->private = i;
+
+ pgoff_start += 1 << i;
+ pages -= 1 << i;
+ }
+ }
+}
+
static bool dev_dax_supported(struct block_device *bdev)
{
char buf[BDEVNAME_SIZE];
@@ -234,7 +297,7 @@ static bool attach_nvm_set(struct bch_nvm_namespace *ns)
struct bch_nvm_namespace *bch_register_namespace(const char *dev_path)
{
struct bch_nvm_namespace *ns;
- int err;
+ int i, err;
pgoff_t pgoff;
char buf[BDEVNAME_SIZE];
struct block_device *bdev;
@@ -292,6 +355,15 @@ struct bch_nvm_namespace *bch_register_namespace(const char *dev_path)
ns->bdev = bdev;
ns->nvm_set = only_set;
+ ns->pages_bitmap = bitmap_zalloc(ns->pages_total, GFP_KERNEL);
+ if (!ns->pages_bitmap) {
+ err = -ENOMEM;
+ goto free_ns;
+ }
+
+ for (i = 0; i < MAX_ORDER; i++)
+ INIT_LIST_HEAD(&ns->free_area[i]);
+
mutex_init(&ns->lock);
if (ns->sb->this_namespace_nr == 0) {
@@ -299,12 +371,16 @@ struct bch_nvm_namespace *bch_register_namespace(const char *dev_path)
err = init_owner_info(ns);
if (err < 0) {
pr_info("init_owner_info met error %d\n", err);
- goto free_ns;
+ goto free_bitmap;
}
+ /* init buddy allocator */
+ init_nvm_free_space(ns);
}
return ns;
+free_bitmap:
+ kfree(ns->pages_bitmap);
free_ns:
kfree(ns);
bdput:
diff --git a/drivers/md/bcache/nvm-pages.h b/drivers/md/bcache/nvm-pages.h
index 8850d00a4612..15aa0f15760f 100644
--- a/drivers/md/bcache/nvm-pages.h
+++ b/drivers/md/bcache/nvm-pages.h
@@ -44,6 +44,9 @@ struct bch_nvm_namespace {
u64 pages_total;
pfn_t start_pfn;
+ unsigned long *pages_bitmap;
+ struct list_head free_area[MAX_ORDER];
+
struct dax_device *dax_dev;
struct block_device *bdev;
struct nvm_pages_sb *sb;
--
2.17.1
