From: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
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>
Co-authored-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
Signed-off-by: Coly Li <colyli@xxxxxxx>
---
drivers/md/bcache/nvm-pages.c | 75 ++++++++++++++++++++++++++++++++++-
drivers/md/bcache/nvm-pages.h | 5 +++
2 files changed, 78 insertions(+), 2 deletions(-)
diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
index 4fa8e2764773..7efb99c0fc07 100644
--- a/drivers/md/bcache/nvm-pages.c
+++ b/drivers/md/bcache/nvm-pages.c
@@ -93,6 +93,7 @@ static void release_nvm_namespaces(struct bch_nvm_set *nvm_set)
int i;
for (i = 0; i < nvm_set->total_namespaces_nr; i++) {
+ kvfree(nvm_set->nss[i]->pages_bitmap);
blkdev_put(nvm_set->nss[i]->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXEC);
kfree(nvm_set->nss[i]);
}
@@ -112,6 +113,17 @@ static void *nvm_pgoff_to_vaddr(struct bch_nvm_namespace *ns, pgoff_t pgoff)
return ns->kaddr + (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 bch_owner_list_head *owner_list_head;
@@ -129,6 +141,8 @@ static int init_owner_info(struct bch_nvm_namespace *ns)
only_set->owner_list_size = owner_list_head->size;
only_set->owner_list_used = owner_list_head->used;
+ remove_owner_space(ns, 0, ns->pages_offset/ns->page_size);
+
for (i = 0; i < owner_list_head->used; i++) {
owner_head = &owner_list_head->heads[i];
owner_list = alloc_owner_list(owner_head->uuid, owner_head->label,
@@ -162,6 +176,8 @@ static int init_owner_info(struct bch_nvm_namespace *ns)
do {
struct bch_pgalloc_rec *rec;
+ int order;
+ struct page *page;
for (k = 0; k < nvm_pgalloc_recs->used; k++) {
rec = &nvm_pgalloc_recs->recs[k];
@@ -172,7 +188,17 @@ static int init_owner_info(struct bch_nvm_namespace *ns)
}
extent->kaddr = nvm_pgoff_to_vaddr(extents->ns, rec->pgoff);
extent->nr = rec->nr;
+ WARN_ON(!is_power_of_2(extent->nr));
+
+ /*init struct page: index/private */
+ order = ilog2(extent->nr);
+ page = nvm_vaddr_to_page(ns, extent->kaddr);
+ set_page_private(page, order);
+ page->index = rec->pgoff;
+
list_add_tail(&extent->list, &extents->extent_head);
+ /*remove already alloced space*/
+ remove_owner_space(extents->ns, rec->pgoff, rec->nr);
}
extents->nr += nvm_pgalloc_recs->used;
@@ -197,6 +223,36 @@ 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;
+ long long 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 = BCH_MAX_ORDER - 1; i >= 0 ; i--) {
+ if ((pgoff_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;
+ }
+ }
+
+}
+
static bool attach_nvm_set(struct bch_nvm_namespace *ns)
{
bool rc = true;
@@ -261,7 +317,7 @@ static int read_nvdimm_meta_super(struct block_device *bdev,
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;
@@ -357,6 +413,16 @@ struct bch_nvm_namespace *bch_register_namespace(const char *dev_path)
ns->bdev = bdev;
ns->nvm_set = only_set;
+ ns->pages_bitmap = kvcalloc(BITS_TO_LONGS(ns->pages_total),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!ns->pages_bitmap) {
+ err = -ENOMEM;
+ goto free_ns;
+ }
+
+ for (i = 0; i < BCH_MAX_ORDER; i++)
+ INIT_LIST_HEAD(&ns->free_area[i]);
+
mutex_init(&ns->lock);
if (ns->sb.this_namespace_nr == 0) {
@@ -364,12 +430,17 @@ 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);
}
kfree(path);
return ns;
+
+free_bitmap:
+ kvfree(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 1b10b4b6db0f..ed3431daae06 100644
--- a/drivers/md/bcache/nvm-pages.h
+++ b/drivers/md/bcache/nvm-pages.h
@@ -34,6 +34,7 @@ struct bch_owner_list {
struct bch_nvm_alloced_recs **alloced_recs;
};
+#define BCH_MAX_ORDER 20
struct bch_nvm_namespace {
struct bch_nvm_pages_sb sb;
void *kaddr;
@@ -45,6 +46,10 @@ struct bch_nvm_namespace {
u64 pages_total;
pfn_t start_pfn;
+ unsigned long *pages_bitmap;
+ struct list_head free_area[BCH_MAX_ORDER];
+
+
struct dax_device *dax_dev;
struct block_device *bdev;
struct bch_nvm_set *nvm_set;
--
2.26.2
