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, 561 insertions, 0 deletions

diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c
new file mode 100644
index 000000000..26d10065d
--- /dev/null
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Russell King
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/mman.h>
+#include <linux/shmem_fs.h>
+
+#include <drm/armada_drm.h>
+#include <drm/drm_prime.h>
+
+#include "armada_drm.h"
+#include "armada_gem.h"
+#include "armada_ioctlP.h"
+
+MODULE_IMPORT_NS(DMA_BUF);
+
+static vm_fault_t armada_gem_vm_fault(struct vm_fault *vmf)
+{
+	struct drm_gem_object *gobj = vmf->vma->vm_private_data;
+	struct armada_gem_object *obj = drm_to_armada_gem(gobj);
+	unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
+
+	pfn += (vmf->address - vmf->vma->vm_start) >> PAGE_SHIFT;
+	return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
+}
+
+static const struct vm_operations_struct armada_gem_vm_ops = {
+	.fault	= armada_gem_vm_fault,
+	.open	= drm_gem_vm_open,
+	.close	= drm_gem_vm_close,
+};
+
+static size_t roundup_gem_size(size_t size)
+{
+	return roundup(size, PAGE_SIZE);
+}
+
+void armada_gem_free_object(struct drm_gem_object *obj)
+{
+	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
+	struct armada_private *priv = drm_to_armada_dev(obj->dev);
+
+	DRM_DEBUG_DRIVER("release obj %p\n", dobj);
+
+	drm_gem_free_mmap_offset(&dobj->obj);
+
+	might_lock(&priv->linear_lock);
+
+	if (dobj->page) {
+		/* page backed memory */
+		unsigned int order = get_order(dobj->obj.size);
+		__free_pages(dobj->page, order);
+	} else if (dobj->linear) {
+		/* linear backed memory */
+		mutex_lock(&priv->linear_lock);
+		drm_mm_remove_node(dobj->linear);
+		mutex_unlock(&priv->linear_lock);
+		kfree(dobj->linear);
+		if (dobj->addr)
+			iounmap(dobj->addr);
+	}
+
+	if (dobj->obj.import_attach) {
+		/* We only ever display imported data */
+		if (dobj->sgt)
+			dma_buf_unmap_attachment_unlocked(dobj->obj.import_attach,
+							  dobj->sgt, DMA_TO_DEVICE);
+		drm_prime_gem_destroy(&dobj->obj, NULL);
+	}
+
+	drm_gem_object_release(&dobj->obj);
+
+	kfree(dobj);
+}
+
+int
+armada_gem_linear_back(struct drm_device *dev, struct armada_gem_object *obj)
+{
+	struct armada_private *priv = drm_to_armada_dev(dev);
+	size_t size = obj->obj.size;
+
+	if (obj->page || obj->linear)
+		return 0;
+
+	/*
+	 * If it is a small allocation (typically cursor, which will
+	 * be 32x64 or 64x32 ARGB pixels) try to get it from the system.
+	 * Framebuffers will never be this small (our minimum size for
+	 * framebuffers is larger than this anyway.)  Such objects are
+	 * only accessed by the CPU so we don't need any special handing
+	 * here.
+	 */
+	if (size <= 8192) {
+		unsigned int order = get_order(size);
+		struct page *p = alloc_pages(GFP_KERNEL, order);
+
+		if (p) {
+			obj->addr = page_address(p);
+			obj->phys_addr = page_to_phys(p);
+			obj->page = p;
+
+			memset(obj->addr, 0, PAGE_ALIGN(size));
+		}
+	}
+
+	/*
+	 * We could grab something from DMA if it's enabled, but that
+	 * involves building in a problem:
+	 *
+	 * GEM DMA helper interface uses dma_alloc_coherent(), which provides
+	 * us with an CPU virtual address and a device address.
+	 *
+	 * The CPU virtual address may be either an address in the kernel
+	 * direct mapped region (for example, as it would be on x86) or
+	 * it may be remapped into another part of kernel memory space
+	 * (eg, as it would be on ARM.)  This means virt_to_phys() on the
+	 * returned virtual address is invalid depending on the architecture
+	 * implementation.
+	 *
+	 * The device address may also not be a physical address; it may
+	 * be that there is some kind of remapping between the device and
+	 * system RAM, which makes the use of the device address also
+	 * unsafe to re-use as a physical address.
+	 *
+	 * This makes DRM usage of dma_alloc_coherent() in a generic way
+	 * at best very questionable and unsafe.
+	 */
+
+	/* Otherwise, grab it from our linear allocation */
+	if (!obj->page) {
+		struct drm_mm_node *node;
+		unsigned align = min_t(unsigned, size, SZ_2M);
+		void __iomem *ptr;
+		int ret;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node)
+			return -ENOSPC;
+
+		mutex_lock(&priv->linear_lock);
+		ret = drm_mm_insert_node_generic(&priv->linear, node,
+						 size, align, 0, 0);
+		mutex_unlock(&priv->linear_lock);
+		if (ret) {
+			kfree(node);
+			return ret;
+		}
+
+		obj->linear = node;
+
+		/* Ensure that the memory we're returning is cleared. */
+		ptr = ioremap_wc(obj->linear->start, size);
+		if (!ptr) {
+			mutex_lock(&priv->linear_lock);
+			drm_mm_remove_node(obj->linear);
+			mutex_unlock(&priv->linear_lock);
+			kfree(obj->linear);
+			obj->linear = NULL;
+			return -ENOMEM;
+		}
+
+		memset_io(ptr, 0, size);
+		iounmap(ptr);
+
+		obj->phys_addr = obj->linear->start;
+		obj->dev_addr = obj->linear->start;
+		obj->mapped = true;
+	}
+
+	DRM_DEBUG_DRIVER("obj %p phys %#llx dev %#llx\n", obj,
+			 (unsigned long long)obj->phys_addr,
+			 (unsigned long long)obj->dev_addr);
+
+	return 0;
+}
+
+void *
+armada_gem_map_object(struct drm_device *dev, struct armada_gem_object *dobj)
+{
+	/* only linear objects need to be ioremap'd */
+	if (!dobj->addr && dobj->linear)
+		dobj->addr = ioremap_wc(dobj->phys_addr, dobj->obj.size);
+	return dobj->addr;
+}
+
+static const struct drm_gem_object_funcs armada_gem_object_funcs = {
+	.free = armada_gem_free_object,
+	.export = armada_gem_prime_export,
+	.vm_ops = &armada_gem_vm_ops,
+};
+
+struct armada_gem_object *
+armada_gem_alloc_private_object(struct drm_device *dev, size_t size)
+{
+	struct armada_gem_object *obj;
+
+	size = roundup_gem_size(size);
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return NULL;
+
+	obj->obj.funcs = &armada_gem_object_funcs;
+
+	drm_gem_private_object_init(dev, &obj->obj, size);
+
+	DRM_DEBUG_DRIVER("alloc private obj %p size %zu\n", obj, size);
+
+	return obj;
+}
+
+static struct armada_gem_object *armada_gem_alloc_object(struct drm_device *dev,
+	size_t size)
+{
+	struct armada_gem_object *obj;
+	struct address_space *mapping;
+
+	size = roundup_gem_size(size);
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return NULL;
+
+	obj->obj.funcs = &armada_gem_object_funcs;
+
+	if (drm_gem_object_init(dev, &obj->obj, size)) {
+		kfree(obj);
+		return NULL;
+	}
+
+	mapping = obj->obj.filp->f_mapping;
+	mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
+
+	DRM_DEBUG_DRIVER("alloc obj %p size %zu\n", obj, size);
+
+	return obj;
+}
+
+/* Dumb alloc support */
+int armada_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
+	struct drm_mode_create_dumb *args)
+{
+	struct armada_gem_object *dobj;
+	u32 handle;
+	size_t size;
+	int ret;
+
+	args->pitch = armada_pitch(args->width, args->bpp);
+	args->size = size = args->pitch * args->height;
+
+	dobj = armada_gem_alloc_private_object(dev, size);
+	if (dobj == NULL)
+		return -ENOMEM;
+
+	ret = armada_gem_linear_back(dev, dobj);
+	if (ret)
+		goto err;
+
+	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
+	if (ret)
+		goto err;
+
+	args->handle = handle;
+
+	/* drop reference from allocate - handle holds it now */
+	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
+ err:
+	drm_gem_object_put(&dobj->obj);
+	return ret;
+}
+
+/* Private driver gem ioctls */
+int armada_gem_create_ioctl(struct drm_device *dev, void *data,
+	struct drm_file *file)
+{
+	struct drm_armada_gem_create *args = data;
+	struct armada_gem_object *dobj;
+	size_t size;
+	u32 handle;
+	int ret;
+
+	if (args->size == 0)
+		return -ENOMEM;
+
+	size = args->size;
+
+	dobj = armada_gem_alloc_object(dev, size);
+	if (dobj == NULL)
+		return -ENOMEM;
+
+	ret = drm_gem_handle_create(file, &dobj->obj, &handle);
+	if (ret)
+		goto err;
+
+	args->handle = handle;
+
+	/* drop reference from allocate - handle holds it now */
+	DRM_DEBUG_DRIVER("obj %p size %zu handle %#x\n", dobj, size, handle);
+ err:
+	drm_gem_object_put(&dobj->obj);
+	return ret;
+}
+
+/* Map a shmem-backed object into process memory space */
+int armada_gem_mmap_ioctl(struct drm_device *dev, void *data,
+	struct drm_file *file)
+{
+	struct drm_armada_gem_mmap *args = data;
+	struct armada_gem_object *dobj;
+	unsigned long addr;
+
+	dobj = armada_gem_object_lookup(file, args->handle);
+	if (dobj == NULL)
+		return -ENOENT;
+
+	if (!dobj->obj.filp) {
+		drm_gem_object_put(&dobj->obj);
+		return -EINVAL;
+	}
+
+	addr = vm_mmap(dobj->obj.filp, 0, args->size, PROT_READ | PROT_WRITE,
+		       MAP_SHARED, args->offset);
+	drm_gem_object_put(&dobj->obj);
+	if (IS_ERR_VALUE(addr))
+		return addr;
+
+	args->addr = addr;
+
+	return 0;
+}
+
+int armada_gem_pwrite_ioctl(struct drm_device *dev, void *data,
+	struct drm_file *file)
+{
+	struct drm_armada_gem_pwrite *args = data;
+	struct armada_gem_object *dobj;
+	char __user *ptr;
+	int ret = 0;
+
+	DRM_DEBUG_DRIVER("handle %u off %u size %u ptr 0x%llx\n",
+		args->handle, args->offset, args->size, args->ptr);
+
+	if (args->size == 0)
+		return 0;
+
+	ptr = (char __user *)(uintptr_t)args->ptr;
+
+	if (!access_ok(ptr, args->size))
+		return -EFAULT;
+
+	if (fault_in_readable(ptr, args->size))
+		return -EFAULT;
+
+	dobj = armada_gem_object_lookup(file, args->handle);
+	if (dobj == NULL)
+		return -ENOENT;
+
+	/* Must be a kernel-mapped object */
+	if (!dobj->addr)
+		return -EINVAL;
+
+	if (args->offset > dobj->obj.size ||
+	    args->size > dobj->obj.size - args->offset) {
+		DRM_ERROR("invalid size: object size %u\n", dobj->obj.size);
+		ret = -EINVAL;
+		goto unref;
+	}
+
+	if (copy_from_user(dobj->addr + args->offset, ptr, args->size)) {
+		ret = -EFAULT;
+	} else if (dobj->update) {
+		dobj->update(dobj->update_data);
+		ret = 0;
+	}
+
+ unref:
+	drm_gem_object_put(&dobj->obj);
+	return ret;
+}
+
+/* Prime support */
+static struct sg_table *
+armada_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
+	enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = attach->dmabuf->priv;
+	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
+	struct scatterlist *sg;
+	struct sg_table *sgt;
+	int i;
+
+	sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return NULL;
+
+	if (dobj->obj.filp) {
+		struct address_space *mapping;
+		int count;
+
+		count = dobj->obj.size / PAGE_SIZE;
+		if (sg_alloc_table(sgt, count, GFP_KERNEL))
+			goto free_sgt;
+
+		mapping = dobj->obj.filp->f_mapping;
+
+		for_each_sgtable_sg(sgt, sg, i) {
+			struct page *page;
+
+			page = shmem_read_mapping_page(mapping, i);
+			if (IS_ERR(page))
+				goto release;
+
+			sg_set_page(sg, page, PAGE_SIZE, 0);
+		}
+
+		if (dma_map_sgtable(attach->dev, sgt, dir, 0))
+			goto release;
+	} else if (dobj->page) {
+		/* Single contiguous page */
+		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
+			goto free_sgt;
+
+		sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
+
+		if (dma_map_sgtable(attach->dev, sgt, dir, 0))
+			goto free_table;
+	} else if (dobj->linear) {
+		/* Single contiguous physical region - no struct page */
+		if (sg_alloc_table(sgt, 1, GFP_KERNEL))
+			goto free_sgt;
+		sg_dma_address(sgt->sgl) = dobj->dev_addr;
+		sg_dma_len(sgt->sgl) = dobj->obj.size;
+	} else {
+		goto free_sgt;
+	}
+	return sgt;
+
+ release:
+	for_each_sgtable_sg(sgt, sg, i)
+		if (sg_page(sg))
+			put_page(sg_page(sg));
+ free_table:
+	sg_free_table(sgt);
+ free_sgt:
+	kfree(sgt);
+	return NULL;
+}
+
+static void armada_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
+	struct sg_table *sgt, enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = attach->dmabuf->priv;
+	struct armada_gem_object *dobj = drm_to_armada_gem(obj);
+	int i;
+
+	if (!dobj->linear)
+		dma_unmap_sgtable(attach->dev, sgt, dir, 0);
+
+	if (dobj->obj.filp) {
+		struct scatterlist *sg;
+
+		for_each_sgtable_sg(sgt, sg, i)
+			put_page(sg_page(sg));
+	}
+
+	sg_free_table(sgt);
+	kfree(sgt);
+}
+
+static int
+armada_gem_dmabuf_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
+{
+	return -EINVAL;
+}
+
+static const struct dma_buf_ops armada_gem_prime_dmabuf_ops = {
+	.map_dma_buf	= armada_gem_prime_map_dma_buf,
+	.unmap_dma_buf	= armada_gem_prime_unmap_dma_buf,
+	.release	= drm_gem_dmabuf_release,
+	.mmap		= armada_gem_dmabuf_mmap,
+};
+
+struct dma_buf *
+armada_gem_prime_export(struct drm_gem_object *obj, int flags)
+{
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+	exp_info.ops = &armada_gem_prime_dmabuf_ops;
+	exp_info.size = obj->size;
+	exp_info.flags = O_RDWR;
+	exp_info.priv = obj;
+
+	return drm_gem_dmabuf_export(obj->dev, &exp_info);
+}
+
+struct drm_gem_object *
+armada_gem_prime_import(struct drm_device *dev, struct dma_buf *buf)
+{
+	struct dma_buf_attachment *attach;
+	struct armada_gem_object *dobj;
+
+	if (buf->ops == &armada_gem_prime_dmabuf_ops) {
+		struct drm_gem_object *obj = buf->priv;
+		if (obj->dev == dev) {
+			/*
+			 * Importing our own dmabuf(s) increases the
+			 * refcount on the gem object itself.
+			 */
+			drm_gem_object_get(obj);
+			return obj;
+		}
+	}
+
+	attach = dma_buf_attach(buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_CAST(attach);
+
+	dobj = armada_gem_alloc_private_object(dev, buf->size);
+	if (!dobj) {
+		dma_buf_detach(buf, attach);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dobj->obj.import_attach = attach;
+	get_dma_buf(buf);
+
+	/*
+	 * Don't call dma_buf_map_attachment() here - it maps the
+	 * scatterlist immediately for DMA, and this is not always
+	 * an appropriate thing to do.
+	 */
+	return &dobj->obj;
+}
+
+int armada_gem_map_import(struct armada_gem_object *dobj)
+{
+	int ret;
+
+	dobj->sgt = dma_buf_map_attachment_unlocked(dobj->obj.import_attach,
+						    DMA_TO_DEVICE);
+	if (IS_ERR(dobj->sgt)) {
+		ret = PTR_ERR(dobj->sgt);
+		dobj->sgt = NULL;
+		DRM_ERROR("dma_buf_map_attachment() error: %d\n", ret);
+		return ret;
+	}
+	if (dobj->sgt->nents > 1) {
+		DRM_ERROR("dma_buf_map_attachment() returned an (unsupported) scattered list\n");
+		return -EINVAL;
+	}
+	if (sg_dma_len(dobj->sgt->sgl) < dobj->obj.size) {
+		DRM_ERROR("dma_buf_map_attachment() returned a small buffer\n");
+		return -EINVAL;
+	}
+	dobj->dev_addr = sg_dma_address(dobj->sgt->sgl);
+	dobj->mapped = true;
+	return 0;
+}