Merge: CNB95: net: page_pool: update to the v6.8

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/4058

JIRA: https://issues.redhat.com/browse/RHEL-31941
Depends: !4000
Depends: !4041

The series updates page_pool to upstream version v6.8.
Both have to be updated at once due to circular dependencies.

Signed-off-by: Petr Oros <poros@redhat.com>

Approved-by: Ivan Vecera <ivecera@redhat.com>
Approved-by: José Ignacio Tornos Martínez <jtornosm@redhat.com>
Approved-by: Rafael Aquini <aquini@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Scott Weaver <scweaver@redhat.com>

Author: swvrrh

Documentation/netlink/specs/netdev.yaml

@@ -86,6 +86,112 @@ attribute-sets:
              See Documentation/networking/xdp-rx-metadata.rst for more details.
         type: u64
         enum: xdp-rx-metadata
+  -
+    name: page-pool
+    attributes:
+      -
+        name: id
+        doc: Unique ID of a Page Pool instance.
+        type: uint
+        checks:
+          min: 1
+          max: u32-max
+      -
+        name: ifindex
+        doc: |
+          ifindex of the netdev to which the pool belongs.
+          May be reported as 0 if the page pool was allocated for a netdev
+          which got destroyed already (page pools may outlast their netdevs
+          because they wait for all memory to be returned).
+        type: u32
+        checks:
+          min: 1
+          max: s32-max
+      -
+        name: napi-id
+        doc: Id of NAPI using this Page Pool instance.
+        type: uint
+        checks:
+          min: 1
+          max: u32-max
+      -
+        name: inflight
+        type: uint
+        doc: |
+          Number of outstanding references to this page pool (allocated
+          but yet to be freed pages). Allocated pages may be held in
+          socket receive queues, driver receive ring, page pool recycling
+          ring, the page pool cache, etc.
+      -
+        name: inflight-mem
+        type: uint
+        doc: |
+          Amount of memory held by inflight pages.
+      -
+        name: detach-time
+        type: uint
+        doc: |
+          Seconds in CLOCK_BOOTTIME of when Page Pool was detached by
+          the driver. Once detached Page Pool can no longer be used to
+          allocate memory.
+          Page Pools wait for all the memory allocated from them to be freed
+          before truly disappearing. "Detached" Page Pools cannot be
+          "re-attached", they are just waiting to disappear.
+          Attribute is absent if Page Pool has not been detached, and
+          can still be used to allocate new memory.
+  -
+    name: page-pool-info
+    subset-of: page-pool
+    attributes:
+      -
+        name: id
+      -
+        name: ifindex
+  -
+    name: page-pool-stats
+    doc: |
+      Page pool statistics, see docs for struct page_pool_stats
+      for information about individual statistics.
+    attributes:
+      -
+        name: info
+        doc: Page pool identifying information.
+        type: nest
+        nested-attributes: page-pool-info
+      -
+        name: alloc-fast
+        type: uint
+        value: 8 # reserve some attr ids in case we need more metadata later
+      -
+        name: alloc-slow
+        type: uint
+      -
+        name: alloc-slow-high-order
+        type: uint
+      -
+        name: alloc-empty
+        type: uint
+      -
+        name: alloc-refill
+        type: uint
+      -
+        name: alloc-waive
+        type: uint
+      -
+        name: recycle-cached
+        type: uint
+      -
+        name: recycle-cache-full
+        type: uint
+      -
+        name: recycle-ring
+        type: uint
+      -
+        name: recycle-ring-full
+        type: uint
+      -
+        name: recycle-released-refcnt
+        type: uint
 
 operations:
   list:
@@ -120,8 +226,74 @@ operations:
       doc: Notification about device configuration being changed.
       notify: dev-get
       mcgrp: mgmt
+    -
+      name: page-pool-get
+      doc: |
+        Get / dump information about Page Pools.
+        (Only Page Pools associated with a net_device can be listed.)
+      attribute-set: page-pool
+      do:
+        request:
+          attributes:
+            - id
+        reply: &pp-reply
+          attributes:
+            - id
+            - ifindex
+            - napi-id
+            - inflight
+            - inflight-mem
+            - detach-time
+      dump:
+        reply: *pp-reply
+      config-cond: page-pool
+    -
+      name: page-pool-add-ntf
+      doc: Notification about page pool appearing.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
+    -
+      name: page-pool-del-ntf
+      doc: Notification about page pool disappearing.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
+    -
+      name: page-pool-change-ntf
+      doc: Notification about page pool configuration being changed.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
+    -
+      name: page-pool-stats-get
+      doc: Get page pool statistics.
+      attribute-set: page-pool-stats
+      do:
+        request:
+          attributes:
+            - info
+        reply: &pp-stats-reply
+          attributes:
+            - info
+            - alloc-fast
+            - alloc-slow
+            - alloc-slow-high-order
+            - alloc-empty
+            - alloc-refill
+            - alloc-waive
+            - recycle-cached
+            - recycle-cache-full
+            - recycle-ring
+            - recycle-ring-full
+            - recycle-released-refcnt
+      dump:
+        reply: *pp-stats-reply
+      config-cond: page-pool-stats
 
 mcast-groups:
   list:
     -
       name: mgmt
+    -
+      name: page-pool

Documentation/networking/page_pool.rst

@@ -4,22 +4,8 @@
 Page Pool API
 =============
 
-The page_pool allocator is optimized for the XDP mode that uses one frame
-per-page, but it can fallback on the regular page allocator APIs.
-
-Basic use involves replacing alloc_pages() calls with the
-page_pool_alloc_pages() call.  Drivers should use page_pool_dev_alloc_pages()
-replacing dev_alloc_pages().
-
-API keeps track of inflight pages, in order to let API user know
-when it is safe to free a page_pool object.  Thus, API users
-must run page_pool_release_page() when a page is leaving the page_pool or
-call page_pool_put_page() where appropriate in order to maintain correct
-accounting.
-
-API user must call page_pool_put_page() once on a page, as it
-will either recycle the page, or in case of refcnt > 1, it will
-release the DMA mapping and inflight state accounting.
+.. kernel-doc:: include/net/page_pool/helpers.h
+   :doc: page_pool allocator
 
 Architecture overview
 =====================
@@ -55,6 +41,11 @@ Architecture overview
                           |   Fast cache    |     |  ptr-ring cache  |
                           +-----------------+     +------------------+
 
+Monitoring
+==========
+Information about page pools on the system can be accessed via the netdev
+genetlink family (see Documentation/netlink/specs/netdev.yaml).
+
 API interface
 =============
 The number of pools created **must** match the number of hardware queues
@@ -72,7 +63,9 @@ a page will cause no race conditions is enough.
 
 .. kernel-doc:: include/net/page_pool/helpers.h
    :identifiers: page_pool_put_page page_pool_put_full_page
-		 page_pool_recycle_direct page_pool_dev_alloc_pages
+		 page_pool_recycle_direct page_pool_free_va
+		 page_pool_dev_alloc_pages page_pool_dev_alloc_frag
+		 page_pool_dev_alloc page_pool_dev_alloc_va
 		 page_pool_get_dma_addr page_pool_get_dma_dir
 
 .. kernel-doc:: net/core/page_pool.c
@@ -119,8 +112,9 @@ page_pool_get_stats() and structures described below are available.
 It takes a  pointer to a ``struct page_pool`` and a pointer to a struct
 page_pool_stats allocated by the caller.
 
-The API will fill in the provided struct page_pool_stats with
-statistics about the page_pool.
+Older drivers expose page pool statistics via ethtool or debugfs.
+The same statistics are accessible via the netlink netdev family
+in a driver-independent fashion.
 
 .. kernel-doc:: include/net/page_pool/types.h
    :identifiers: struct page_pool_recycle_stats
@@ -175,7 +169,7 @@ NAPI poller
             if XDP_DROP:
                 page_pool_recycle_direct(page_pool, page);
         } else (packet_is_skb) {
-            page_pool_release_page(page_pool, page);
+            skb_mark_for_recycle(skb);
             new_page = page_pool_dev_alloc_pages(page_pool);
         }
     }