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, 449 insertions, 0 deletions

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
new file mode 100644
index 000000000..f90975e00
--- /dev/null
+++ b/drivers/of/of_reserved_mem.c
@@ -0,0 +1,449 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Device tree based initialization code for reserved memory.
+ *
+ * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Author: Marek Szyprowski <m.szyprowski@samsung.com>
+ * Author: Josh Cartwright <joshc@codeaurora.org>
+ */
+
+#define pr_fmt(fmt)	"OF: reserved mem: " fmt
+
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/kmemleak.h>
+#include <linux/cma.h>
+
+#include "of_private.h"
+
+#define MAX_RESERVED_REGIONS	64
+static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
+static int reserved_mem_count;
+
+static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	phys_addr_t base;
+	int err = 0;
+
+	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
+	align = !align ? SMP_CACHE_BYTES : align;
+	base = memblock_phys_alloc_range(size, align, start, end);
+	if (!base)
+		return -ENOMEM;
+
+	*res_base = base;
+	if (nomap) {
+		err = memblock_mark_nomap(base, size);
+		if (err)
+			memblock_phys_free(base, size);
+	}
+
+	kmemleak_ignore_phys(base);
+
+	return err;
+}
+
+/*
+ * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
+ */
+void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+				      phys_addr_t base, phys_addr_t size)
+{
+	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
+
+	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
+		pr_err("not enough space for all defined regions.\n");
+		return;
+	}
+
+	rmem->fdt_node = node;
+	rmem->name = uname;
+	rmem->base = base;
+	rmem->size = size;
+
+	reserved_mem_count++;
+	return;
+}
+
+/*
+ * __reserved_mem_alloc_size() - allocate reserved memory described by
+ *	'size', 'alignment'  and 'alloc-ranges' properties.
+ */
+static int __init __reserved_mem_alloc_size(unsigned long node,
+	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t start = 0, end = 0;
+	phys_addr_t base = 0, align = 0, size;
+	int len;
+	const __be32 *prop;
+	bool nomap;
+	int ret;
+
+	prop = of_get_flat_dt_prop(node, "size", &len);
+	if (!prop)
+		return -EINVAL;
+
+	if (len != dt_root_size_cells * sizeof(__be32)) {
+		pr_err("invalid size property in '%s' node.\n", uname);
+		return -EINVAL;
+	}
+	size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+	prop = of_get_flat_dt_prop(node, "alignment", &len);
+	if (prop) {
+		if (len != dt_root_addr_cells * sizeof(__be32)) {
+			pr_err("invalid alignment property in '%s' node.\n",
+				uname);
+			return -EINVAL;
+		}
+		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	/* Need adjust the alignment to satisfy the CMA requirement */
+	if (IS_ENABLED(CONFIG_CMA)
+	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
+	    && of_get_flat_dt_prop(node, "reusable", NULL)
+	    && !nomap)
+		align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
+
+	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
+	if (prop) {
+
+		if (len % t_len != 0) {
+			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
+			       uname);
+			return -EINVAL;
+		}
+
+		base = 0;
+
+		while (len > 0) {
+			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
+			end = start + dt_mem_next_cell(dt_root_size_cells,
+						       &prop);
+
+			ret = early_init_dt_alloc_reserved_memory_arch(size,
+					align, start, end, nomap, &base);
+			if (ret == 0) {
+				pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+					uname, &base,
+					(unsigned long)(size / SZ_1M));
+				break;
+			}
+			len -= t_len;
+		}
+
+	} else {
+		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+							0, 0, nomap, &base);
+		if (ret == 0)
+			pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+				uname, &base, (unsigned long)(size / SZ_1M));
+	}
+
+	if (base == 0) {
+		pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
+		       uname, (unsigned long)(size / SZ_1M));
+		return -ENOMEM;
+	}
+
+	*res_base = base;
+	*res_size = size;
+
+	return 0;
+}
+
+static const struct of_device_id __rmem_of_table_sentinel
+	__used __section("__reservedmem_of_table_end");
+
+/*
+ * __reserved_mem_init_node() - call region specific reserved memory init code
+ */
+static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
+{
+	extern const struct of_device_id __reservedmem_of_table[];
+	const struct of_device_id *i;
+	int ret = -ENOENT;
+
+	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
+		reservedmem_of_init_fn initfn = i->data;
+		const char *compat = i->compatible;
+
+		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
+			continue;
+
+		ret = initfn(rmem);
+		if (ret == 0) {
+			pr_info("initialized node %s, compatible id %s\n",
+				rmem->name, compat);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int __init __rmem_cmp(const void *a, const void *b)
+{
+	const struct reserved_mem *ra = a, *rb = b;
+
+	if (ra->base < rb->base)
+		return -1;
+
+	if (ra->base > rb->base)
+		return 1;
+
+	/*
+	 * Put the dynamic allocations (address == 0, size == 0) before static
+	 * allocations at address 0x0 so that overlap detection works
+	 * correctly.
+	 */
+	if (ra->size < rb->size)
+		return -1;
+	if (ra->size > rb->size)
+		return 1;
+
+	return 0;
+}
+
+static void __init __rmem_check_for_overlap(void)
+{
+	int i;
+
+	if (reserved_mem_count < 2)
+		return;
+
+	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
+	     __rmem_cmp, NULL);
+	for (i = 0; i < reserved_mem_count - 1; i++) {
+		struct reserved_mem *this, *next;
+
+		this = &reserved_mem[i];
+		next = &reserved_mem[i + 1];
+
+		if (this->base + this->size > next->base) {
+			phys_addr_t this_end, next_end;
+
+			this_end = this->base + this->size;
+			next_end = next->base + next->size;
+			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
+			       this->name, &this->base, &this_end,
+			       next->name, &next->base, &next_end);
+		}
+	}
+}
+
+/**
+ * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
+ */
+void __init fdt_init_reserved_mem(void)
+{
+	int i;
+
+	/* check for overlapping reserved regions */
+	__rmem_check_for_overlap();
+
+	for (i = 0; i < reserved_mem_count; i++) {
+		struct reserved_mem *rmem = &reserved_mem[i];
+		unsigned long node = rmem->fdt_node;
+		int len;
+		const __be32 *prop;
+		int err = 0;
+		bool nomap;
+
+		nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+		prop = of_get_flat_dt_prop(node, "phandle", &len);
+		if (!prop)
+			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
+		if (prop)
+			rmem->phandle = of_read_number(prop, len/4);
+
+		if (rmem->size == 0)
+			err = __reserved_mem_alloc_size(node, rmem->name,
+						 &rmem->base, &rmem->size);
+		if (err == 0) {
+			err = __reserved_mem_init_node(rmem);
+			if (err != 0 && err != -ENOENT) {
+				pr_info("node %s compatible matching fail\n",
+					rmem->name);
+				if (nomap)
+					memblock_clear_nomap(rmem->base, rmem->size);
+				else
+					memblock_phys_free(rmem->base,
+							   rmem->size);
+			}
+		}
+	}
+}
+
+static inline struct reserved_mem *__find_rmem(struct device_node *node)
+{
+	unsigned int i;
+
+	if (!node->phandle)
+		return NULL;
+
+	for (i = 0; i < reserved_mem_count; i++)
+		if (reserved_mem[i].phandle == node->phandle)
+			return &reserved_mem[i];
+	return NULL;
+}
+
+struct rmem_assigned_device {
+	struct device *dev;
+	struct reserved_mem *rmem;
+	struct list_head list;
+};
+
+static LIST_HEAD(of_rmem_assigned_device_list);
+static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
+
+/**
+ * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
+ *					  given device
+ * @dev:	Pointer to the device to configure
+ * @np:		Pointer to the device_node with 'reserved-memory' property
+ * @idx:	Index of selected region
+ *
+ * This function assigns respective DMA-mapping operations based on reserved
+ * memory region specified by 'memory-region' property in @np node to the @dev
+ * device. When driver needs to use more than one reserved memory region, it
+ * should allocate child devices and initialize regions by name for each of
+ * child device.
+ *
+ * Returns error code or zero on success.
+ */
+int of_reserved_mem_device_init_by_idx(struct device *dev,
+				       struct device_node *np, int idx)
+{
+	struct rmem_assigned_device *rd;
+	struct device_node *target;
+	struct reserved_mem *rmem;
+	int ret;
+
+	if (!np || !dev)
+		return -EINVAL;
+
+	target = of_parse_phandle(np, "memory-region", idx);
+	if (!target)
+		return -ENODEV;
+
+	if (!of_device_is_available(target)) {
+		of_node_put(target);
+		return 0;
+	}
+
+	rmem = __find_rmem(target);
+	of_node_put(target);
+
+	if (!rmem || !rmem->ops || !rmem->ops->device_init)
+		return -EINVAL;
+
+	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	ret = rmem->ops->device_init(rmem, dev);
+	if (ret == 0) {
+		rd->dev = dev;
+		rd->rmem = rmem;
+
+		mutex_lock(&of_rmem_assigned_device_mutex);
+		list_add(&rd->list, &of_rmem_assigned_device_list);
+		mutex_unlock(&of_rmem_assigned_device_mutex);
+
+		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+	} else {
+		kfree(rd);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
+
+/**
+ * of_reserved_mem_device_init_by_name() - assign named reserved memory region
+ *					   to given device
+ * @dev: pointer to the device to configure
+ * @np: pointer to the device node with 'memory-region' property
+ * @name: name of the selected memory region
+ *
+ * Returns: 0 on success or a negative error-code on failure.
+ */
+int of_reserved_mem_device_init_by_name(struct device *dev,
+					struct device_node *np,
+					const char *name)
+{
+	int idx = of_property_match_string(np, "memory-region-names", name);
+
+	return of_reserved_mem_device_init_by_idx(dev, np, idx);
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ * @dev:	Pointer to the device to deconfigure
+ *
+ * This function releases structures allocated for memory region handling for
+ * the given device.
+ */
+void of_reserved_mem_device_release(struct device *dev)
+{
+	struct rmem_assigned_device *rd, *tmp;
+	LIST_HEAD(release_list);
+
+	mutex_lock(&of_rmem_assigned_device_mutex);
+	list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
+		if (rd->dev == dev)
+			list_move_tail(&rd->list, &release_list);
+	}
+	mutex_unlock(&of_rmem_assigned_device_mutex);
+
+	list_for_each_entry_safe(rd, tmp, &release_list, list) {
+		if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
+			rd->rmem->ops->device_release(rd->rmem, dev);
+
+		kfree(rd);
+	}
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
+
+/**
+ * of_reserved_mem_lookup() - acquire reserved_mem from a device node
+ * @np:		node pointer of the desired reserved-memory region
+ *
+ * This function allows drivers to acquire a reference to the reserved_mem
+ * struct based on a device node handle.
+ *
+ * Returns a reserved_mem reference, or NULL on error.
+ */
+struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
+{
+	const char *name;
+	int i;
+
+	if (!np->full_name)
+		return NULL;
+
+	name = kbasename(np->full_name);
+	for (i = 0; i < reserved_mem_count; i++)
+		if (!strcmp(reserved_mem[i].name, name))
+			return &reserved_mem[i];
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);