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, 860 insertions, 0 deletions

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
new file mode 100644
index 000000000..dcc16d7cb
--- /dev/null
+++ b/drivers/cxl/core/hdm.c
@@ -0,0 +1,860 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
+#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+
+#include "cxlmem.h"
+#include "core.h"
+
+/**
+ * DOC: cxl core hdm
+ *
+ * Compute Express Link Host Managed Device Memory, starting with the
+ * CXL 2.0 specification, is managed by an array of HDM Decoder register
+ * instances per CXL port and per CXL endpoint. Define common helpers
+ * for enumerating these registers and capabilities.
+ */
+
+DECLARE_RWSEM(cxl_dpa_rwsem);
+
+static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
+			   int *target_map)
+{
+	int rc;
+
+	rc = cxl_decoder_add_locked(cxld, target_map);
+	if (rc) {
+		put_device(&cxld->dev);
+		dev_err(&port->dev, "Failed to add decoder\n");
+		return rc;
+	}
+
+	rc = cxl_decoder_autoremove(&port->dev, cxld);
+	if (rc)
+		return rc;
+
+	dev_dbg(&cxld->dev, "Added to port %s\n", dev_name(&port->dev));
+
+	return 0;
+}
+
+/*
+ * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability Structure)
+ * single ported host-bridges need not publish a decoder capability when a
+ * passthrough decode can be assumed, i.e. all transactions that the uport sees
+ * are claimed and passed to the single dport. Disable the range until the first
+ * CXL region is enumerated / activated.
+ */
+int devm_cxl_add_passthrough_decoder(struct cxl_port *port)
+{
+	struct cxl_switch_decoder *cxlsd;
+	struct cxl_dport *dport = NULL;
+	int single_port_map[1];
+	unsigned long index;
+
+	cxlsd = cxl_switch_decoder_alloc(port, 1);
+	if (IS_ERR(cxlsd))
+		return PTR_ERR(cxlsd);
+
+	device_lock_assert(&port->dev);
+
+	xa_for_each(&port->dports, index, dport)
+		break;
+	single_port_map[0] = dport->port_id;
+
+	return add_hdm_decoder(port, &cxlsd->cxld, single_port_map);
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_add_passthrough_decoder, CXL);
+
+static void parse_hdm_decoder_caps(struct cxl_hdm *cxlhdm)
+{
+	u32 hdm_cap;
+
+	hdm_cap = readl(cxlhdm->regs.hdm_decoder + CXL_HDM_DECODER_CAP_OFFSET);
+	cxlhdm->decoder_count = cxl_hdm_decoder_count(hdm_cap);
+	cxlhdm->target_count =
+		FIELD_GET(CXL_HDM_DECODER_TARGET_COUNT_MASK, hdm_cap);
+	if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_11_8, hdm_cap))
+		cxlhdm->interleave_mask |= GENMASK(11, 8);
+	if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_14_12, hdm_cap))
+		cxlhdm->interleave_mask |= GENMASK(14, 12);
+}
+
+static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb,
+				struct cxl_component_regs *regs)
+{
+	struct cxl_register_map map = {
+		.resource = port->component_reg_phys,
+		.base = crb,
+		.max_size = CXL_COMPONENT_REG_BLOCK_SIZE,
+	};
+
+	cxl_probe_component_regs(&port->dev, crb, &map.component_map);
+	if (!map.component_map.hdm_decoder.valid) {
+		dev_err(&port->dev, "HDM decoder registers invalid\n");
+		return -ENXIO;
+	}
+
+	return cxl_map_component_regs(&port->dev, regs, &map,
+				      BIT(CXL_CM_CAP_CAP_ID_HDM));
+}
+
+/**
+ * devm_cxl_setup_hdm - map HDM decoder component registers
+ * @port: cxl_port to map
+ */
+struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port)
+{
+	struct device *dev = &port->dev;
+	struct cxl_hdm *cxlhdm;
+	void __iomem *crb;
+	int rc;
+
+	cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL);
+	if (!cxlhdm)
+		return ERR_PTR(-ENOMEM);
+
+	cxlhdm->port = port;
+	crb = ioremap(port->component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE);
+	if (!crb) {
+		dev_err(dev, "No component registers mapped\n");
+		return ERR_PTR(-ENXIO);
+	}
+
+	rc = map_hdm_decoder_regs(port, crb, &cxlhdm->regs);
+	iounmap(crb);
+	if (rc)
+		return ERR_PTR(rc);
+
+	parse_hdm_decoder_caps(cxlhdm);
+	if (cxlhdm->decoder_count == 0) {
+		dev_err(dev, "Spec violation. Caps invalid\n");
+		return ERR_PTR(-ENXIO);
+	}
+
+	dev_set_drvdata(dev, cxlhdm);
+
+	return cxlhdm;
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL);
+
+static void __cxl_dpa_debug(struct seq_file *file, struct resource *r, int depth)
+{
+	unsigned long long start = r->start, end = r->end;
+
+	seq_printf(file, "%*s%08llx-%08llx : %s\n", depth * 2, "", start, end,
+		   r->name);
+}
+
+void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds)
+{
+	struct resource *p1, *p2;
+
+	down_read(&cxl_dpa_rwsem);
+	for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) {
+		__cxl_dpa_debug(file, p1, 0);
+		for (p2 = p1->child; p2; p2 = p2->sibling)
+			__cxl_dpa_debug(file, p2, 1);
+	}
+	up_read(&cxl_dpa_rwsem);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL);
+
+/*
+ * Must be called in a context that synchronizes against this decoder's
+ * port ->remove() callback (like an endpoint decoder sysfs attribute)
+ */
+static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
+{
+	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+	struct cxl_port *port = cxled_to_port(cxled);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct resource *res = cxled->dpa_res;
+	resource_size_t skip_start;
+
+	lockdep_assert_held_write(&cxl_dpa_rwsem);
+
+	/* save @skip_start, before @res is released */
+	skip_start = res->start - cxled->skip;
+	__release_region(&cxlds->dpa_res, res->start, resource_size(res));
+	if (cxled->skip)
+		__release_region(&cxlds->dpa_res, skip_start, cxled->skip);
+	cxled->skip = 0;
+	cxled->dpa_res = NULL;
+	put_device(&cxled->cxld.dev);
+	port->hdm_end--;
+}
+
+static void cxl_dpa_release(void *cxled)
+{
+	down_write(&cxl_dpa_rwsem);
+	__cxl_dpa_release(cxled);
+	up_write(&cxl_dpa_rwsem);
+}
+
+/*
+ * Must be called from context that will not race port device
+ * unregistration, like decoder sysfs attribute methods
+ */
+static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
+{
+	struct cxl_port *port = cxled_to_port(cxled);
+
+	lockdep_assert_held_write(&cxl_dpa_rwsem);
+	devm_remove_action(&port->dev, cxl_dpa_release, cxled);
+	__cxl_dpa_release(cxled);
+}
+
+static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
+			     resource_size_t base, resource_size_t len,
+			     resource_size_t skipped)
+{
+	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+	struct cxl_port *port = cxled_to_port(cxled);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct device *dev = &port->dev;
+	struct resource *res;
+
+	lockdep_assert_held_write(&cxl_dpa_rwsem);
+
+	if (!len)
+		goto success;
+
+	if (cxled->dpa_res) {
+		dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
+			port->id, cxled->cxld.id, cxled->dpa_res);
+		return -EBUSY;
+	}
+
+	if (port->hdm_end + 1 != cxled->cxld.id) {
+		/*
+		 * Assumes alloc and commit order is always in hardware instance
+		 * order per expectations from 8.2.5.12.20 Committing Decoder
+		 * Programming that enforce decoder[m] committed before
+		 * decoder[m+1] commit start.
+		 */
+		dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id,
+			cxled->cxld.id, port->id, port->hdm_end + 1);
+		return -EBUSY;
+	}
+
+	if (skipped) {
+		res = __request_region(&cxlds->dpa_res, base - skipped, skipped,
+				       dev_name(&cxled->cxld.dev), 0);
+		if (!res) {
+			dev_dbg(dev,
+				"decoder%d.%d: failed to reserve skipped space\n",
+				port->id, cxled->cxld.id);
+			return -EBUSY;
+		}
+	}
+	res = __request_region(&cxlds->dpa_res, base, len,
+			       dev_name(&cxled->cxld.dev), 0);
+	if (!res) {
+		dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n",
+			port->id, cxled->cxld.id);
+		if (skipped)
+			__release_region(&cxlds->dpa_res, base - skipped,
+					 skipped);
+		return -EBUSY;
+	}
+	cxled->dpa_res = res;
+	cxled->skip = skipped;
+
+	if (resource_contains(&cxlds->pmem_res, res))
+		cxled->mode = CXL_DECODER_PMEM;
+	else if (resource_contains(&cxlds->ram_res, res))
+		cxled->mode = CXL_DECODER_RAM;
+	else {
+		dev_dbg(dev, "decoder%d.%d: %pr mixed\n", port->id,
+			cxled->cxld.id, cxled->dpa_res);
+		cxled->mode = CXL_DECODER_MIXED;
+	}
+
+success:
+	port->hdm_end++;
+	get_device(&cxled->cxld.dev);
+	return 0;
+}
+
+static int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
+				resource_size_t base, resource_size_t len,
+				resource_size_t skipped)
+{
+	struct cxl_port *port = cxled_to_port(cxled);
+	int rc;
+
+	down_write(&cxl_dpa_rwsem);
+	rc = __cxl_dpa_reserve(cxled, base, len, skipped);
+	up_write(&cxl_dpa_rwsem);
+
+	if (rc)
+		return rc;
+
+	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
+}
+
+resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled)
+{
+	resource_size_t size = 0;
+
+	down_read(&cxl_dpa_rwsem);
+	if (cxled->dpa_res)
+		size = resource_size(cxled->dpa_res);
+	up_read(&cxl_dpa_rwsem);
+
+	return size;
+}
+
+resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
+{
+	resource_size_t base = -1;
+
+	down_read(&cxl_dpa_rwsem);
+	if (cxled->dpa_res)
+		base = cxled->dpa_res->start;
+	up_read(&cxl_dpa_rwsem);
+
+	return base;
+}
+
+int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
+{
+	struct cxl_port *port = cxled_to_port(cxled);
+	struct device *dev = &cxled->cxld.dev;
+	int rc;
+
+	down_write(&cxl_dpa_rwsem);
+	if (!cxled->dpa_res) {
+		rc = 0;
+		goto out;
+	}
+	if (cxled->cxld.region) {
+		dev_dbg(dev, "decoder assigned to: %s\n",
+			dev_name(&cxled->cxld.region->dev));
+		rc = -EBUSY;
+		goto out;
+	}
+	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
+		dev_dbg(dev, "decoder enabled\n");
+		rc = -EBUSY;
+		goto out;
+	}
+	if (cxled->cxld.id != port->hdm_end) {
+		dev_dbg(dev, "expected decoder%d.%d\n", port->id,
+			port->hdm_end);
+		rc = -EBUSY;
+		goto out;
+	}
+	devm_cxl_dpa_release(cxled);
+	rc = 0;
+out:
+	up_write(&cxl_dpa_rwsem);
+	return rc;
+}
+
+int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
+		     enum cxl_decoder_mode mode)
+{
+	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct device *dev = &cxled->cxld.dev;
+	int rc;
+
+	switch (mode) {
+	case CXL_DECODER_RAM:
+	case CXL_DECODER_PMEM:
+		break;
+	default:
+		dev_dbg(dev, "unsupported mode: %d\n", mode);
+		return -EINVAL;
+	}
+
+	down_write(&cxl_dpa_rwsem);
+	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
+		rc = -EBUSY;
+		goto out;
+	}
+
+	/*
+	 * Only allow modes that are supported by the current partition
+	 * configuration
+	 */
+	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
+		dev_dbg(dev, "no available pmem capacity\n");
+		rc = -ENXIO;
+		goto out;
+	}
+	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
+		dev_dbg(dev, "no available ram capacity\n");
+		rc = -ENXIO;
+		goto out;
+	}
+
+	cxled->mode = mode;
+	rc = 0;
+out:
+	up_write(&cxl_dpa_rwsem);
+
+	return rc;
+}
+
+int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)
+{
+	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+	resource_size_t free_ram_start, free_pmem_start;
+	struct cxl_port *port = cxled_to_port(cxled);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct device *dev = &cxled->cxld.dev;
+	resource_size_t start, avail, skip;
+	struct resource *p, *last;
+	int rc;
+
+	down_write(&cxl_dpa_rwsem);
+	if (cxled->cxld.region) {
+		dev_dbg(dev, "decoder attached to %s\n",
+			dev_name(&cxled->cxld.region->dev));
+		rc = -EBUSY;
+		goto out;
+	}
+
+	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
+		dev_dbg(dev, "decoder enabled\n");
+		rc = -EBUSY;
+		goto out;
+	}
+
+	for (p = cxlds->ram_res.child, last = NULL; p; p = p->sibling)
+		last = p;
+	if (last)
+		free_ram_start = last->end + 1;
+	else
+		free_ram_start = cxlds->ram_res.start;
+
+	for (p = cxlds->pmem_res.child, last = NULL; p; p = p->sibling)
+		last = p;
+	if (last)
+		free_pmem_start = last->end + 1;
+	else
+		free_pmem_start = cxlds->pmem_res.start;
+
+	if (cxled->mode == CXL_DECODER_RAM) {
+		start = free_ram_start;
+		avail = cxlds->ram_res.end - start + 1;
+		skip = 0;
+	} else if (cxled->mode == CXL_DECODER_PMEM) {
+		resource_size_t skip_start, skip_end;
+
+		start = free_pmem_start;
+		avail = cxlds->pmem_res.end - start + 1;
+		skip_start = free_ram_start;
+
+		/*
+		 * If some pmem is already allocated, then that allocation
+		 * already handled the skip.
+		 */
+		if (cxlds->pmem_res.child &&
+		    skip_start == cxlds->pmem_res.child->start)
+			skip_end = skip_start - 1;
+		else
+			skip_end = start - 1;
+		skip = skip_end - skip_start + 1;
+	} else {
+		dev_dbg(dev, "mode not set\n");
+		rc = -EINVAL;
+		goto out;
+	}
+
+	if (size > avail) {
+		dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size,
+			cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem",
+			&avail);
+		rc = -ENOSPC;
+		goto out;
+	}
+
+	rc = __cxl_dpa_reserve(cxled, start, size, skip);
+out:
+	up_write(&cxl_dpa_rwsem);
+
+	if (rc)
+		return rc;
+
+	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
+}
+
+static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
+{
+	u16 eig;
+	u8 eiw;
+
+	/*
+	 * Input validation ensures these warns never fire, but otherwise
+	 * suppress unititalized variable usage warnings.
+	 */
+	if (WARN_ONCE(ways_to_eiw(cxld->interleave_ways, &eiw),
+		      "invalid interleave_ways: %d\n", cxld->interleave_ways))
+		return;
+	if (WARN_ONCE(granularity_to_eig(cxld->interleave_granularity, &eig),
+		      "invalid interleave_granularity: %d\n",
+		      cxld->interleave_granularity))
+		return;
+
+	u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
+	u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK);
+	*ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
+}
+
+static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
+{
+	u32p_replace_bits(ctrl, !!(cxld->target_type == 3),
+			  CXL_HDM_DECODER0_CTRL_TYPE);
+}
+
+static int cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
+{
+	struct cxl_dport **t = &cxlsd->target[0];
+	int ways = cxlsd->cxld.interleave_ways;
+
+	if (dev_WARN_ONCE(&cxlsd->cxld.dev,
+			  ways > 8 || ways > cxlsd->nr_targets,
+			  "ways: %d overflows targets: %d\n", ways,
+			  cxlsd->nr_targets))
+		return -ENXIO;
+
+	*tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id);
+	if (ways > 1)
+		*tgt |= FIELD_PREP(GENMASK(15, 8), t[1]->port_id);
+	if (ways > 2)
+		*tgt |= FIELD_PREP(GENMASK(23, 16), t[2]->port_id);
+	if (ways > 3)
+		*tgt |= FIELD_PREP(GENMASK(31, 24), t[3]->port_id);
+	if (ways > 4)
+		*tgt |= FIELD_PREP(GENMASK_ULL(39, 32), t[4]->port_id);
+	if (ways > 5)
+		*tgt |= FIELD_PREP(GENMASK_ULL(47, 40), t[5]->port_id);
+	if (ways > 6)
+		*tgt |= FIELD_PREP(GENMASK_ULL(55, 48), t[6]->port_id);
+	if (ways > 7)
+		*tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id);
+
+	return 0;
+}
+
+/*
+ * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set
+ * committed or error within 10ms, but just be generous with 20ms to account for
+ * clock skew and other marginal behavior
+ */
+#define COMMIT_TIMEOUT_MS 20
+static int cxld_await_commit(void __iomem *hdm, int id)
+{
+	u32 ctrl;
+	int i;
+
+	for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
+		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
+			ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
+			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+			return -EIO;
+		}
+		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
+			return 0;
+		fsleep(1000);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int cxl_decoder_commit(struct cxl_decoder *cxld)
+{
+	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
+	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	int id = cxld->id, rc;
+	u64 base, size;
+	u32 ctrl;
+
+	if (cxld->flags & CXL_DECODER_F_ENABLE)
+		return 0;
+
+	if (port->commit_end + 1 != id) {
+		dev_dbg(&port->dev,
+			"%s: out of order commit, expected decoder%d.%d\n",
+			dev_name(&cxld->dev), port->id, port->commit_end + 1);
+		return -EBUSY;
+	}
+
+	down_read(&cxl_dpa_rwsem);
+	/* common decoder settings */
+	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id));
+	cxld_set_interleave(cxld, &ctrl);
+	cxld_set_type(cxld, &ctrl);
+	base = cxld->hpa_range.start;
+	size = range_len(&cxld->hpa_range);
+
+	writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
+	writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
+	writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
+	writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
+
+	if (is_switch_decoder(&cxld->dev)) {
+		struct cxl_switch_decoder *cxlsd =
+			to_cxl_switch_decoder(&cxld->dev);
+		void __iomem *tl_hi = hdm + CXL_HDM_DECODER0_TL_HIGH(id);
+		void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id);
+		u64 targets;
+
+		rc = cxlsd_set_targets(cxlsd, &targets);
+		if (rc) {
+			dev_dbg(&port->dev, "%s: target configuration error\n",
+				dev_name(&cxld->dev));
+			goto err;
+		}
+
+		writel(upper_32_bits(targets), tl_hi);
+		writel(lower_32_bits(targets), tl_lo);
+	} else {
+		struct cxl_endpoint_decoder *cxled =
+			to_cxl_endpoint_decoder(&cxld->dev);
+		void __iomem *sk_hi = hdm + CXL_HDM_DECODER0_SKIP_HIGH(id);
+		void __iomem *sk_lo = hdm + CXL_HDM_DECODER0_SKIP_LOW(id);
+
+		writel(upper_32_bits(cxled->skip), sk_hi);
+		writel(lower_32_bits(cxled->skip), sk_lo);
+	}
+
+	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+	up_read(&cxl_dpa_rwsem);
+
+	port->commit_end++;
+	rc = cxld_await_commit(hdm, cxld->id);
+err:
+	if (rc) {
+		dev_dbg(&port->dev, "%s: error %d committing decoder\n",
+			dev_name(&cxld->dev), rc);
+		cxld->reset(cxld);
+		return rc;
+	}
+	cxld->flags |= CXL_DECODER_F_ENABLE;
+
+	return 0;
+}
+
+static int cxl_decoder_reset(struct cxl_decoder *cxld)
+{
+	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
+	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	int id = cxld->id;
+	u32 ctrl;
+
+	if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
+		return 0;
+
+	if (port->commit_end != id) {
+		dev_dbg(&port->dev,
+			"%s: out of order reset, expected decoder%d.%d\n",
+			dev_name(&cxld->dev), port->id, port->commit_end);
+		return -EBUSY;
+	}
+
+	down_read(&cxl_dpa_rwsem);
+	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+	ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
+	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
+
+	writel(0, hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
+	writel(0, hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
+	writel(0, hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
+	writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
+	up_read(&cxl_dpa_rwsem);
+
+	port->commit_end--;
+	cxld->flags &= ~CXL_DECODER_F_ENABLE;
+
+	return 0;
+}
+
+static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
+			    int *target_map, void __iomem *hdm, int which,
+			    u64 *dpa_base)
+{
+	struct cxl_endpoint_decoder *cxled = NULL;
+	u64 size, base, skip, dpa_size;
+	bool committed;
+	u32 remainder;
+	int i, rc;
+	u32 ctrl;
+	union {
+		u64 value;
+		unsigned char target_id[8];
+	} target_list;
+
+	if (is_endpoint_decoder(&cxld->dev))
+		cxled = to_cxl_endpoint_decoder(&cxld->dev);
+
+	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
+	base = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which));
+	size = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which));
+	committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED);
+	cxld->commit = cxl_decoder_commit;
+	cxld->reset = cxl_decoder_reset;
+
+	if (!committed)
+		size = 0;
+	if (base == U64_MAX || size == U64_MAX) {
+		dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",
+			 port->id, cxld->id);
+		return -ENXIO;
+	}
+
+	cxld->hpa_range = (struct range) {
+		.start = base,
+		.end = base + size - 1,
+	};
+
+	/* decoders are enabled if committed */
+	if (committed) {
+		cxld->flags |= CXL_DECODER_F_ENABLE;
+		if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
+			cxld->flags |= CXL_DECODER_F_LOCK;
+		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl))
+			cxld->target_type = CXL_DECODER_EXPANDER;
+		else
+			cxld->target_type = CXL_DECODER_ACCELERATOR;
+		if (cxld->id != port->commit_end + 1) {
+			dev_warn(&port->dev,
+				 "decoder%d.%d: Committed out of order\n",
+				 port->id, cxld->id);
+			return -ENXIO;
+		}
+		port->commit_end = cxld->id;
+	} else {
+		/* unless / until type-2 drivers arrive, assume type-3 */
+		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl) == 0) {
+			ctrl |= CXL_HDM_DECODER0_CTRL_TYPE;
+			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
+		}
+		cxld->target_type = CXL_DECODER_EXPANDER;
+	}
+	rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
+			  &cxld->interleave_ways);
+	if (rc) {
+		dev_warn(&port->dev,
+			 "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",
+			 port->id, cxld->id, ctrl);
+		return rc;
+	}
+	rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
+				 &cxld->interleave_granularity);
+	if (rc)
+		return rc;
+
+	if (!cxled) {
+		target_list.value =
+			ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which));
+		for (i = 0; i < cxld->interleave_ways; i++)
+			target_map[i] = target_list.target_id[i];
+
+		return 0;
+	}
+
+	if (!committed)
+		return 0;
+
+	dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder);
+	if (remainder) {
+		dev_err(&port->dev,
+			"decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n",
+			port->id, cxld->id, size, cxld->interleave_ways);
+		return -ENXIO;
+	}
+	skip = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SKIP_LOW(which));
+	rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip);
+	if (rc) {
+		dev_err(&port->dev,
+			"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
+			port->id, cxld->id, *dpa_base,
+			*dpa_base + dpa_size + skip - 1, rc);
+		return rc;
+	}
+	*dpa_base += dpa_size + skip;
+	return 0;
+}
+
+/**
+ * devm_cxl_enumerate_decoders - add decoder objects per HDM register set
+ * @cxlhdm: Structure to populate with HDM capabilities
+ */
+int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
+{
+	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	struct cxl_port *port = cxlhdm->port;
+	int i, committed;
+	u64 dpa_base = 0;
+	u32 ctrl;
+
+	/*
+	 * Since the register resource was recently claimed via request_region()
+	 * be careful about trusting the "not-committed" status until the commit
+	 * timeout has elapsed.  The commit timeout is 10ms (CXL 2.0
+	 * 8.2.5.12.20), but double it to be tolerant of any clock skew between
+	 * host and target.
+	 */
+	for (i = 0, committed = 0; i < cxlhdm->decoder_count; i++) {
+		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));
+		if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED)
+			committed++;
+	}
+
+	/* ensure that future checks of committed can be trusted */
+	if (committed != cxlhdm->decoder_count)
+		msleep(20);
+
+	for (i = 0; i < cxlhdm->decoder_count; i++) {
+		int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 };
+		int rc, target_count = cxlhdm->target_count;
+		struct cxl_decoder *cxld;
+
+		if (is_cxl_endpoint(port)) {
+			struct cxl_endpoint_decoder *cxled;
+
+			cxled = cxl_endpoint_decoder_alloc(port);
+			if (IS_ERR(cxled)) {
+				dev_warn(&port->dev,
+					 "Failed to allocate the decoder\n");
+				return PTR_ERR(cxled);
+			}
+			cxld = &cxled->cxld;
+		} else {
+			struct cxl_switch_decoder *cxlsd;
+
+			cxlsd = cxl_switch_decoder_alloc(port, target_count);
+			if (IS_ERR(cxlsd)) {
+				dev_warn(&port->dev,
+					 "Failed to allocate the decoder\n");
+				return PTR_ERR(cxlsd);
+			}
+			cxld = &cxlsd->cxld;
+		}
+
+		rc = init_hdm_decoder(port, cxld, target_map, hdm, i, &dpa_base);
+		if (rc) {
+			put_device(&cxld->dev);
+			return rc;
+		}
+		rc = add_hdm_decoder(port, cxld, target_map);
+		if (rc) {
+			dev_warn(&port->dev,
+				 "Failed to add decoder to port\n");
+			return rc;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);