Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 495 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c
new file mode 100644
index 000000000..e42800718
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_atomic_helper.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/dma-resv.h>
+#include <linux/dma-fence-chain.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include "drm_internal.h"
+
+/**
+ * DOC: overview
+ *
+ * The GEM atomic helpers library implements generic atomic-commit
+ * functions for drivers that use GEM objects. Currently, it provides
+ * synchronization helpers, and plane state and framebuffer BO mappings
+ * for planes with shadow buffers.
+ *
+ * Before scanout, a plane's framebuffer needs to be synchronized with
+ * possible writers that draw into the framebuffer. All drivers should
+ * call drm_gem_plane_helper_prepare_fb() from their implementation of
+ * struct &drm_plane_helper.prepare_fb . It sets the plane's fence from
+ * the framebuffer so that the DRM core can synchronize access automatically.
+ *
+ * drm_gem_plane_helper_prepare_fb() can also be used directly as
+ * implementation of prepare_fb. For drivers based on
+ * struct drm_simple_display_pipe, drm_gem_simple_display_pipe_prepare_fb()
+ * provides equivalent functionality.
+ *
+ * .. code-block:: c
+ *
+ *	#include <drm/drm_gem_atomic_helper.h>
+ *
+ *	struct drm_plane_helper_funcs driver_plane_helper_funcs = {
+ *		...,
+ *		. prepare_fb = drm_gem_plane_helper_prepare_fb,
+ *	};
+ *
+ *	struct drm_simple_display_pipe_funcs driver_pipe_funcs = {
+ *		...,
+ *		. prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
+ *	};
+ *
+ * A driver using a shadow buffer copies the content of the shadow buffers
+ * into the HW's framebuffer memory during an atomic update. This requires
+ * a mapping of the shadow buffer into kernel address space. The mappings
+ * cannot be established by commit-tail functions, such as atomic_update,
+ * as this would violate locking rules around dma_buf_vmap().
+ *
+ * The helpers for shadow-buffered planes establish and release mappings,
+ * and provide struct drm_shadow_plane_state, which stores the plane's mapping
+ * for commit-tail functions.
+ *
+ * Shadow-buffered planes can easily be enabled by using the provided macros
+ * %DRM_GEM_SHADOW_PLANE_FUNCS and %DRM_GEM_SHADOW_PLANE_HELPER_FUNCS.
+ * These macros set up the plane and plane-helper callbacks to point to the
+ * shadow-buffer helpers.
+ *
+ * .. code-block:: c
+ *
+ *	#include <drm/drm_gem_atomic_helper.h>
+ *
+ *	struct drm_plane_funcs driver_plane_funcs = {
+ *		...,
+ *		DRM_GEM_SHADOW_PLANE_FUNCS,
+ *	};
+ *
+ *	struct drm_plane_helper_funcs driver_plane_helper_funcs = {
+ *		...,
+ *		DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
+ *	};
+ *
+ * In the driver's atomic-update function, shadow-buffer mappings are available
+ * from the plane state. Use to_drm_shadow_plane_state() to upcast from
+ * struct drm_plane_state.
+ *
+ * .. code-block:: c
+ *
+ *	void driver_plane_atomic_update(struct drm_plane *plane,
+ *					struct drm_plane_state *old_plane_state)
+ *	{
+ *		struct drm_plane_state *plane_state = plane->state;
+ *		struct drm_shadow_plane_state *shadow_plane_state =
+ *			to_drm_shadow_plane_state(plane_state);
+ *
+ *		// access shadow buffer via shadow_plane_state->map
+ *	}
+ *
+ * A mapping address for each of the framebuffer's buffer object is stored in
+ * struct &drm_shadow_plane_state.map. The mappings are valid while the state
+ * is being used.
+ *
+ * Drivers that use struct drm_simple_display_pipe can use
+ * %DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS to initialize the rsp
+ * callbacks. Access to shadow-buffer mappings is similar to regular
+ * atomic_update.
+ *
+ * .. code-block:: c
+ *
+ *	struct drm_simple_display_pipe_funcs driver_pipe_funcs = {
+ *		...,
+ *		DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
+ *	};
+ *
+ *	void driver_pipe_enable(struct drm_simple_display_pipe *pipe,
+ *				struct drm_crtc_state *crtc_state,
+ *				struct drm_plane_state *plane_state)
+ *	{
+ *		struct drm_shadow_plane_state *shadow_plane_state =
+ *			to_drm_shadow_plane_state(plane_state);
+ *
+ *		// access shadow buffer via shadow_plane_state->map
+ *	}
+ */
+
+/*
+ * Plane Helpers
+ */
+
+/**
+ * drm_gem_plane_helper_prepare_fb() - Prepare a GEM backed framebuffer
+ * @plane: Plane
+ * @state: Plane state the fence will be attached to
+ *
+ * This function extracts the exclusive fence from &drm_gem_object.resv and
+ * attaches it to plane state for the atomic helper to wait on. This is
+ * necessary to correctly implement implicit synchronization for any buffers
+ * shared as a struct &dma_buf. This function can be used as the
+ * &drm_plane_helper_funcs.prepare_fb callback.
+ *
+ * There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple
+ * GEM based framebuffer drivers which have their buffers always pinned in
+ * memory.
+ *
+ * This function is the default implementation for GEM drivers of
+ * &drm_plane_helper_funcs.prepare_fb if no callback is provided.
+ */
+int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane,
+				    struct drm_plane_state *state)
+{
+	struct dma_fence *fence = dma_fence_get(state->fence);
+	enum dma_resv_usage usage;
+	size_t i;
+	int ret;
+
+	if (!state->fb)
+		return 0;
+
+	/*
+	 * Only add the kernel fences here if there is already a fence set via
+	 * explicit fencing interfaces on the atomic ioctl.
+	 *
+	 * This way explicit fencing can be used to overrule implicit fencing,
+	 * which is important to make explicit fencing use-cases work: One
+	 * example is using one buffer for 2 screens with different refresh
+	 * rates. Implicit fencing will clamp rendering to the refresh rate of
+	 * the slower screen, whereas explicit fence allows 2 independent
+	 * render and display loops on a single buffer. If a driver allows
+	 * obeys both implicit and explicit fences for plane updates, then it
+	 * will break all the benefits of explicit fencing.
+	 */
+	usage = fence ? DMA_RESV_USAGE_KERNEL : DMA_RESV_USAGE_WRITE;
+
+	for (i = 0; i < state->fb->format->num_planes; ++i) {
+		struct drm_gem_object *obj = drm_gem_fb_get_obj(state->fb, i);
+		struct dma_fence *new;
+
+		if (!obj) {
+			ret = -EINVAL;
+			goto error;
+		}
+
+		ret = dma_resv_get_singleton(obj->resv, usage, &new);
+		if (ret)
+			goto error;
+
+		if (new && fence) {
+			struct dma_fence_chain *chain = dma_fence_chain_alloc();
+
+			if (!chain) {
+				ret = -ENOMEM;
+				goto error;
+			}
+
+			dma_fence_chain_init(chain, fence, new, 1);
+			fence = &chain->base;
+
+		} else if (new) {
+			fence = new;
+		}
+	}
+
+	dma_fence_put(state->fence);
+	state->fence = fence;
+	return 0;
+
+error:
+	dma_fence_put(fence);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb);
+
+/**
+ * drm_gem_simple_display_pipe_prepare_fb - prepare_fb helper for &drm_simple_display_pipe
+ * @pipe: Simple display pipe
+ * @plane_state: Plane state
+ *
+ * This function uses drm_gem_plane_helper_prepare_fb() to extract the fences
+ * from &drm_gem_object.resv and attaches them to the plane state for the atomic
+ * helper to wait on. This is necessary to correctly implement implicit
+ * synchronization for any buffers shared as a struct &dma_buf. Drivers can use
+ * this as their &drm_simple_display_pipe_funcs.prepare_fb callback.
+ *
+ * See drm_gem_plane_helper_prepare_fb() for a discussion of implicit and
+ * explicit fencing in atomic modeset updates.
+ */
+int drm_gem_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
+					   struct drm_plane_state *plane_state)
+{
+	return drm_gem_plane_helper_prepare_fb(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(drm_gem_simple_display_pipe_prepare_fb);
+
+/*
+ * Shadow-buffered Planes
+ */
+
+/**
+ * __drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
+ * @plane: the plane
+ * @new_shadow_plane_state: the new shadow-buffered plane state
+ *
+ * This function duplicates shadow-buffered plane state. This is helpful for drivers
+ * that subclass struct drm_shadow_plane_state.
+ *
+ * The function does not duplicate existing mappings of the shadow buffers.
+ * Mappings are maintained during the atomic commit by the plane's prepare_fb
+ * and cleanup_fb helpers. See drm_gem_prepare_shadow_fb() and drm_gem_cleanup_shadow_fb()
+ * for corresponding helpers.
+ */
+void
+__drm_gem_duplicate_shadow_plane_state(struct drm_plane *plane,
+				       struct drm_shadow_plane_state *new_shadow_plane_state)
+{
+	__drm_atomic_helper_plane_duplicate_state(plane, &new_shadow_plane_state->base);
+}
+EXPORT_SYMBOL(__drm_gem_duplicate_shadow_plane_state);
+
+/**
+ * drm_gem_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
+ * @plane: the plane
+ *
+ * This function implements struct &drm_plane_funcs.atomic_duplicate_state for
+ * shadow-buffered planes. It assumes the existing state to be of type
+ * struct drm_shadow_plane_state and it allocates the new state to be of this
+ * type.
+ *
+ * The function does not duplicate existing mappings of the shadow buffers.
+ * Mappings are maintained during the atomic commit by the plane's prepare_fb
+ * and cleanup_fb helpers. See drm_gem_prepare_shadow_fb() and drm_gem_cleanup_shadow_fb()
+ * for corresponding helpers.
+ *
+ * Returns:
+ * A pointer to a new plane state on success, or NULL otherwise.
+ */
+struct drm_plane_state *
+drm_gem_duplicate_shadow_plane_state(struct drm_plane *plane)
+{
+	struct drm_plane_state *plane_state = plane->state;
+	struct drm_shadow_plane_state *new_shadow_plane_state;
+
+	if (!plane_state)
+		return NULL;
+
+	new_shadow_plane_state = kzalloc(sizeof(*new_shadow_plane_state), GFP_KERNEL);
+	if (!new_shadow_plane_state)
+		return NULL;
+	__drm_gem_duplicate_shadow_plane_state(plane, new_shadow_plane_state);
+
+	return &new_shadow_plane_state->base;
+}
+EXPORT_SYMBOL(drm_gem_duplicate_shadow_plane_state);
+
+/**
+ * __drm_gem_destroy_shadow_plane_state - cleans up shadow-buffered plane state
+ * @shadow_plane_state: the shadow-buffered plane state
+ *
+ * This function cleans up shadow-buffered plane state. Helpful for drivers that
+ * subclass struct drm_shadow_plane_state.
+ */
+void __drm_gem_destroy_shadow_plane_state(struct drm_shadow_plane_state *shadow_plane_state)
+{
+	__drm_atomic_helper_plane_destroy_state(&shadow_plane_state->base);
+}
+EXPORT_SYMBOL(__drm_gem_destroy_shadow_plane_state);
+
+/**
+ * drm_gem_destroy_shadow_plane_state - deletes shadow-buffered plane state
+ * @plane: the plane
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct &drm_plane_funcs.atomic_destroy_state
+ * for shadow-buffered planes. It expects that mappings of shadow buffers
+ * have been released already.
+ */
+void drm_gem_destroy_shadow_plane_state(struct drm_plane *plane,
+					struct drm_plane_state *plane_state)
+{
+	struct drm_shadow_plane_state *shadow_plane_state =
+		to_drm_shadow_plane_state(plane_state);
+
+	__drm_gem_destroy_shadow_plane_state(shadow_plane_state);
+	kfree(shadow_plane_state);
+}
+EXPORT_SYMBOL(drm_gem_destroy_shadow_plane_state);
+
+/**
+ * __drm_gem_reset_shadow_plane - resets a shadow-buffered plane
+ * @plane: the plane
+ * @shadow_plane_state: the shadow-buffered plane state
+ *
+ * This function resets state for shadow-buffered planes. Helpful
+ * for drivers that subclass struct drm_shadow_plane_state.
+ */
+void __drm_gem_reset_shadow_plane(struct drm_plane *plane,
+				  struct drm_shadow_plane_state *shadow_plane_state)
+{
+	__drm_atomic_helper_plane_reset(plane, &shadow_plane_state->base);
+}
+EXPORT_SYMBOL(__drm_gem_reset_shadow_plane);
+
+/**
+ * drm_gem_reset_shadow_plane - resets a shadow-buffered plane
+ * @plane: the plane
+ *
+ * This function implements struct &drm_plane_funcs.reset_plane for
+ * shadow-buffered planes. It assumes the current plane state to be
+ * of type struct drm_shadow_plane and it allocates the new state of
+ * this type.
+ */
+void drm_gem_reset_shadow_plane(struct drm_plane *plane)
+{
+	struct drm_shadow_plane_state *shadow_plane_state;
+
+	if (plane->state) {
+		drm_gem_destroy_shadow_plane_state(plane, plane->state);
+		plane->state = NULL; /* must be set to NULL here */
+	}
+
+	shadow_plane_state = kzalloc(sizeof(*shadow_plane_state), GFP_KERNEL);
+	if (!shadow_plane_state)
+		return;
+	__drm_gem_reset_shadow_plane(plane, shadow_plane_state);
+}
+EXPORT_SYMBOL(drm_gem_reset_shadow_plane);
+
+/**
+ * drm_gem_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
+ * @plane: the plane
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct &drm_plane_helper_funcs.begin_fb_access. It
+ * maps all buffer objects of the plane's framebuffer into kernel address
+ * space and stores them in struct &drm_shadow_plane_state.map. The first data
+ * bytes are available in struct &drm_shadow_plane_state.data.
+ *
+ * See drm_gem_end_shadow_fb_access() for cleanup.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drm_gem_begin_shadow_fb_access(struct drm_plane *plane, struct drm_plane_state *plane_state)
+{
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+	struct drm_framebuffer *fb = plane_state->fb;
+
+	if (!fb)
+		return 0;
+
+	return drm_gem_fb_vmap(fb, shadow_plane_state->map, shadow_plane_state->data);
+}
+EXPORT_SYMBOL(drm_gem_begin_shadow_fb_access);
+
+/**
+ * drm_gem_end_shadow_fb_access - releases shadow framebuffers from CPU access
+ * @plane: the plane
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct &drm_plane_helper_funcs.end_fb_access. It
+ * undoes all effects of drm_gem_begin_shadow_fb_access() in reverse order.
+ *
+ * See drm_gem_begin_shadow_fb_access() for more information.
+ */
+void drm_gem_end_shadow_fb_access(struct drm_plane *plane, struct drm_plane_state *plane_state)
+{
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+	struct drm_framebuffer *fb = plane_state->fb;
+
+	if (!fb)
+		return;
+
+	drm_gem_fb_vunmap(fb, shadow_plane_state->map);
+}
+EXPORT_SYMBOL(drm_gem_end_shadow_fb_access);
+
+/**
+ * drm_gem_simple_kms_begin_shadow_fb_access - prepares shadow framebuffers for CPU access
+ * @pipe: the simple display pipe
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct drm_simple_display_funcs.begin_fb_access.
+ *
+ * See drm_gem_begin_shadow_fb_access() for details and
+ * drm_gem_simple_kms_cleanup_shadow_fb() for cleanup.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drm_gem_simple_kms_begin_shadow_fb_access(struct drm_simple_display_pipe *pipe,
+					      struct drm_plane_state *plane_state)
+{
+	return drm_gem_begin_shadow_fb_access(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(drm_gem_simple_kms_begin_shadow_fb_access);
+
+/**
+ * drm_gem_simple_kms_end_shadow_fb_access - releases shadow framebuffers from CPU access
+ * @pipe: the simple display pipe
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct drm_simple_display_funcs.end_fb_access.
+ * It undoes all effects of drm_gem_simple_kms_begin_shadow_fb_access() in
+ * reverse order.
+ *
+ * See drm_gem_simple_kms_begin_shadow_fb_access().
+ */
+void drm_gem_simple_kms_end_shadow_fb_access(struct drm_simple_display_pipe *pipe,
+					     struct drm_plane_state *plane_state)
+{
+	drm_gem_end_shadow_fb_access(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(drm_gem_simple_kms_end_shadow_fb_access);
+
+/**
+ * drm_gem_simple_kms_reset_shadow_plane - resets a shadow-buffered plane
+ * @pipe: the simple display pipe
+ *
+ * This function implements struct drm_simple_display_funcs.reset_plane
+ * for shadow-buffered planes.
+ */
+void drm_gem_simple_kms_reset_shadow_plane(struct drm_simple_display_pipe *pipe)
+{
+	drm_gem_reset_shadow_plane(&pipe->plane);
+}
+EXPORT_SYMBOL(drm_gem_simple_kms_reset_shadow_plane);
+
+/**
+ * drm_gem_simple_kms_duplicate_shadow_plane_state - duplicates shadow-buffered plane state
+ * @pipe: the simple display pipe
+ *
+ * This function implements struct drm_simple_display_funcs.duplicate_plane_state
+ * for shadow-buffered planes. It does not duplicate existing mappings of the shadow
+ * buffers. Mappings are maintained during the atomic commit by the plane's prepare_fb
+ * and cleanup_fb helpers.
+ *
+ * Returns:
+ * A pointer to a new plane state on success, or NULL otherwise.
+ */
+struct drm_plane_state *
+drm_gem_simple_kms_duplicate_shadow_plane_state(struct drm_simple_display_pipe *pipe)
+{
+	return drm_gem_duplicate_shadow_plane_state(&pipe->plane);
+}
+EXPORT_SYMBOL(drm_gem_simple_kms_duplicate_shadow_plane_state);
+
+/**
+ * drm_gem_simple_kms_destroy_shadow_plane_state - resets shadow-buffered plane state
+ * @pipe: the simple display pipe
+ * @plane_state: the plane state of type struct drm_shadow_plane_state
+ *
+ * This function implements struct drm_simple_display_funcs.destroy_plane_state
+ * for shadow-buffered planes. It expects that mappings of shadow buffers
+ * have been released already.
+ */
+void drm_gem_simple_kms_destroy_shadow_plane_state(struct drm_simple_display_pipe *pipe,
+						   struct drm_plane_state *plane_state)
+{
+	drm_gem_destroy_shadow_plane_state(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(drm_gem_simple_kms_destroy_shadow_plane_state);