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, 884 insertions, 0 deletions

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
new file mode 100644
index 000000000..b03fba212
--- /dev/null
+++ b/drivers/cxl/core/mbox.c
@@ -0,0 +1,884 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2020 Intel Corporation. All rights reserved. */
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/security.h>
+#include <linux/debugfs.h>
+#include <linux/mutex.h>
+#include <cxlmem.h>
+#include <cxl.h>
+
+#include "core.h"
+
+static bool cxl_raw_allow_all;
+
+/**
+ * DOC: cxl mbox
+ *
+ * Core implementation of the CXL 2.0 Type-3 Memory Device Mailbox. The
+ * implementation is used by the cxl_pci driver to initialize the device
+ * and implement the cxl_mem.h IOCTL UAPI. It also implements the
+ * backend of the cxl_pmem_ctl() transport for LIBNVDIMM.
+ */
+
+#define cxl_for_each_cmd(cmd)                                                  \
+	for ((cmd) = &cxl_mem_commands[0];                                     \
+	     ((cmd) - cxl_mem_commands) < ARRAY_SIZE(cxl_mem_commands); (cmd)++)
+
+#define CXL_CMD(_id, sin, sout, _flags)                                        \
+	[CXL_MEM_COMMAND_ID_##_id] = {                                         \
+	.info =	{                                                              \
+			.id = CXL_MEM_COMMAND_ID_##_id,                        \
+			.size_in = sin,                                        \
+			.size_out = sout,                                      \
+		},                                                             \
+	.opcode = CXL_MBOX_OP_##_id,                                           \
+	.flags = _flags,                                                       \
+	}
+
+#define CXL_VARIABLE_PAYLOAD	~0U
+/*
+ * This table defines the supported mailbox commands for the driver. This table
+ * is made up of a UAPI structure. Non-negative values as parameters in the
+ * table will be validated against the user's input. For example, if size_in is
+ * 0, and the user passed in 1, it is an error.
+ */
+static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
+	CXL_CMD(IDENTIFY, 0, 0x43, CXL_CMD_FLAG_FORCE_ENABLE),
+#ifdef CONFIG_CXL_MEM_RAW_COMMANDS
+	CXL_CMD(RAW, CXL_VARIABLE_PAYLOAD, CXL_VARIABLE_PAYLOAD, 0),
+#endif
+	CXL_CMD(GET_SUPPORTED_LOGS, 0, CXL_VARIABLE_PAYLOAD, CXL_CMD_FLAG_FORCE_ENABLE),
+	CXL_CMD(GET_FW_INFO, 0, 0x50, 0),
+	CXL_CMD(GET_PARTITION_INFO, 0, 0x20, 0),
+	CXL_CMD(GET_LSA, 0x8, CXL_VARIABLE_PAYLOAD, 0),
+	CXL_CMD(GET_HEALTH_INFO, 0, 0x12, 0),
+	CXL_CMD(GET_LOG, 0x18, CXL_VARIABLE_PAYLOAD, CXL_CMD_FLAG_FORCE_ENABLE),
+	CXL_CMD(SET_PARTITION_INFO, 0x0a, 0, 0),
+	CXL_CMD(SET_LSA, CXL_VARIABLE_PAYLOAD, 0, 0),
+	CXL_CMD(GET_ALERT_CONFIG, 0, 0x10, 0),
+	CXL_CMD(SET_ALERT_CONFIG, 0xc, 0, 0),
+	CXL_CMD(GET_SHUTDOWN_STATE, 0, 0x1, 0),
+	CXL_CMD(SET_SHUTDOWN_STATE, 0x1, 0, 0),
+	CXL_CMD(GET_POISON, 0x10, CXL_VARIABLE_PAYLOAD, 0),
+	CXL_CMD(INJECT_POISON, 0x8, 0, 0),
+	CXL_CMD(CLEAR_POISON, 0x48, 0, 0),
+	CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0),
+	CXL_CMD(SCAN_MEDIA, 0x11, 0, 0),
+	CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0),
+};
+
+/*
+ * Commands that RAW doesn't permit. The rationale for each:
+ *
+ * CXL_MBOX_OP_ACTIVATE_FW: Firmware activation requires adjustment /
+ * coordination of transaction timeout values at the root bridge level.
+ *
+ * CXL_MBOX_OP_SET_PARTITION_INFO: The device memory map may change live
+ * and needs to be coordinated with HDM updates.
+ *
+ * CXL_MBOX_OP_SET_LSA: The label storage area may be cached by the
+ * driver and any writes from userspace invalidates those contents.
+ *
+ * CXL_MBOX_OP_SET_SHUTDOWN_STATE: Set shutdown state assumes no writes
+ * to the device after it is marked clean, userspace can not make that
+ * assertion.
+ *
+ * CXL_MBOX_OP_[GET_]SCAN_MEDIA: The kernel provides a native error list that
+ * is kept up to date with patrol notifications and error management.
+ */
+static u16 cxl_disabled_raw_commands[] = {
+	CXL_MBOX_OP_ACTIVATE_FW,
+	CXL_MBOX_OP_SET_PARTITION_INFO,
+	CXL_MBOX_OP_SET_LSA,
+	CXL_MBOX_OP_SET_SHUTDOWN_STATE,
+	CXL_MBOX_OP_SCAN_MEDIA,
+	CXL_MBOX_OP_GET_SCAN_MEDIA,
+};
+
+/*
+ * Command sets that RAW doesn't permit. All opcodes in this set are
+ * disabled because they pass plain text security payloads over the
+ * user/kernel boundary. This functionality is intended to be wrapped
+ * behind the keys ABI which allows for encrypted payloads in the UAPI
+ */
+static u8 security_command_sets[] = {
+	0x44, /* Sanitize */
+	0x45, /* Persistent Memory Data-at-rest Security */
+	0x46, /* Security Passthrough */
+};
+
+static bool cxl_is_security_command(u16 opcode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(security_command_sets); i++)
+		if (security_command_sets[i] == (opcode >> 8))
+			return true;
+	return false;
+}
+
+static struct cxl_mem_command *cxl_mem_find_command(u16 opcode)
+{
+	struct cxl_mem_command *c;
+
+	cxl_for_each_cmd(c)
+		if (c->opcode == opcode)
+			return c;
+
+	return NULL;
+}
+
+static const char *cxl_mem_opcode_to_name(u16 opcode)
+{
+	struct cxl_mem_command *c;
+
+	c = cxl_mem_find_command(opcode);
+	if (!c)
+		return NULL;
+
+	return cxl_command_names[c->info.id].name;
+}
+
+/**
+ * cxl_internal_send_cmd() - Kernel internal interface to send a mailbox command
+ * @cxlds: The device data for the operation
+ * @mbox_cmd: initialized command to execute
+ *
+ * Context: Any context.
+ * Return:
+ *  * %>=0	- Number of bytes returned in @out.
+ *  * %-E2BIG	- Payload is too large for hardware.
+ *  * %-EBUSY	- Couldn't acquire exclusive mailbox access.
+ *  * %-EFAULT	- Hardware error occurred.
+ *  * %-ENXIO	- Command completed, but device reported an error.
+ *  * %-EIO	- Unexpected output size.
+ *
+ * Mailbox commands may execute successfully yet the device itself reported an
+ * error. While this distinction can be useful for commands from userspace, the
+ * kernel will only be able to use results when both are successful.
+ */
+int cxl_internal_send_cmd(struct cxl_dev_state *cxlds,
+			  struct cxl_mbox_cmd *mbox_cmd)
+{
+	size_t out_size, min_out;
+	int rc;
+
+	if (mbox_cmd->size_in > cxlds->payload_size ||
+	    mbox_cmd->size_out > cxlds->payload_size)
+		return -E2BIG;
+
+	out_size = mbox_cmd->size_out;
+	min_out = mbox_cmd->min_out;
+	rc = cxlds->mbox_send(cxlds, mbox_cmd);
+	if (rc)
+		return rc;
+
+	if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS)
+		return cxl_mbox_cmd_rc2errno(mbox_cmd);
+
+	if (!out_size)
+		return 0;
+
+	/*
+	 * Variable sized output needs to at least satisfy the caller's
+	 * minimum if not the fully requested size.
+	 */
+	if (min_out == 0)
+		min_out = out_size;
+
+	if (mbox_cmd->size_out < min_out)
+		return -EIO;
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_internal_send_cmd, CXL);
+
+static bool cxl_mem_raw_command_allowed(u16 opcode)
+{
+	int i;
+
+	if (!IS_ENABLED(CONFIG_CXL_MEM_RAW_COMMANDS))
+		return false;
+
+	if (security_locked_down(LOCKDOWN_PCI_ACCESS))
+		return false;
+
+	if (cxl_raw_allow_all)
+		return true;
+
+	if (cxl_is_security_command(opcode))
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(cxl_disabled_raw_commands); i++)
+		if (cxl_disabled_raw_commands[i] == opcode)
+			return false;
+
+	return true;
+}
+
+/**
+ * cxl_payload_from_user_allowed() - Check contents of in_payload.
+ * @opcode: The mailbox command opcode.
+ * @payload_in: Pointer to the input payload passed in from user space.
+ *
+ * Return:
+ *  * true	- payload_in passes check for @opcode.
+ *  * false	- payload_in contains invalid or unsupported values.
+ *
+ * The driver may inspect payload contents before sending a mailbox
+ * command from user space to the device. The intent is to reject
+ * commands with input payloads that are known to be unsafe. This
+ * check is not intended to replace the users careful selection of
+ * mailbox command parameters and makes no guarantee that the user
+ * command will succeed, nor that it is appropriate.
+ *
+ * The specific checks are determined by the opcode.
+ */
+static bool cxl_payload_from_user_allowed(u16 opcode, void *payload_in)
+{
+	switch (opcode) {
+	case CXL_MBOX_OP_SET_PARTITION_INFO: {
+		struct cxl_mbox_set_partition_info *pi = payload_in;
+
+		if (pi->flags & CXL_SET_PARTITION_IMMEDIATE_FLAG)
+			return false;
+		break;
+	}
+	default:
+		break;
+	}
+	return true;
+}
+
+static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox,
+			     struct cxl_dev_state *cxlds, u16 opcode,
+			     size_t in_size, size_t out_size, u64 in_payload)
+{
+	*mbox = (struct cxl_mbox_cmd) {
+		.opcode = opcode,
+		.size_in = in_size,
+	};
+
+	if (in_size) {
+		mbox->payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
+						in_size);
+		if (IS_ERR(mbox->payload_in))
+			return PTR_ERR(mbox->payload_in);
+
+		if (!cxl_payload_from_user_allowed(opcode, mbox->payload_in)) {
+			dev_dbg(cxlds->dev, "%s: input payload not allowed\n",
+				cxl_mem_opcode_to_name(opcode));
+			kvfree(mbox->payload_in);
+			return -EBUSY;
+		}
+	}
+
+	/* Prepare to handle a full payload for variable sized output */
+	if (out_size == CXL_VARIABLE_PAYLOAD)
+		mbox->size_out = cxlds->payload_size;
+	else
+		mbox->size_out = out_size;
+
+	if (mbox->size_out) {
+		mbox->payload_out = kvzalloc(mbox->size_out, GFP_KERNEL);
+		if (!mbox->payload_out) {
+			kvfree(mbox->payload_in);
+			return -ENOMEM;
+		}
+	}
+	return 0;
+}
+
+static void cxl_mbox_cmd_dtor(struct cxl_mbox_cmd *mbox)
+{
+	kvfree(mbox->payload_in);
+	kvfree(mbox->payload_out);
+}
+
+static int cxl_to_mem_cmd_raw(struct cxl_mem_command *mem_cmd,
+			      const struct cxl_send_command *send_cmd,
+			      struct cxl_dev_state *cxlds)
+{
+	if (send_cmd->raw.rsvd)
+		return -EINVAL;
+
+	/*
+	 * Unlike supported commands, the output size of RAW commands
+	 * gets passed along without further checking, so it must be
+	 * validated here.
+	 */
+	if (send_cmd->out.size > cxlds->payload_size)
+		return -EINVAL;
+
+	if (!cxl_mem_raw_command_allowed(send_cmd->raw.opcode))
+		return -EPERM;
+
+	dev_WARN_ONCE(cxlds->dev, true, "raw command path used\n");
+
+	*mem_cmd = (struct cxl_mem_command) {
+		.info = {
+			.id = CXL_MEM_COMMAND_ID_RAW,
+			.size_in = send_cmd->in.size,
+			.size_out = send_cmd->out.size,
+		},
+		.opcode = send_cmd->raw.opcode
+	};
+
+	return 0;
+}
+
+static int cxl_to_mem_cmd(struct cxl_mem_command *mem_cmd,
+			  const struct cxl_send_command *send_cmd,
+			  struct cxl_dev_state *cxlds)
+{
+	struct cxl_mem_command *c = &cxl_mem_commands[send_cmd->id];
+	const struct cxl_command_info *info = &c->info;
+
+	if (send_cmd->flags & ~CXL_MEM_COMMAND_FLAG_MASK)
+		return -EINVAL;
+
+	if (send_cmd->rsvd)
+		return -EINVAL;
+
+	if (send_cmd->in.rsvd || send_cmd->out.rsvd)
+		return -EINVAL;
+
+	/* Check that the command is enabled for hardware */
+	if (!test_bit(info->id, cxlds->enabled_cmds))
+		return -ENOTTY;
+
+	/* Check that the command is not claimed for exclusive kernel use */
+	if (test_bit(info->id, cxlds->exclusive_cmds))
+		return -EBUSY;
+
+	/* Check the input buffer is the expected size */
+	if ((info->size_in != CXL_VARIABLE_PAYLOAD) &&
+	    (info->size_in != send_cmd->in.size))
+		return -ENOMEM;
+
+	/* Check the output buffer is at least large enough */
+	if ((info->size_out != CXL_VARIABLE_PAYLOAD) &&
+	    (send_cmd->out.size < info->size_out))
+		return -ENOMEM;
+
+	*mem_cmd = (struct cxl_mem_command) {
+		.info = {
+			.id = info->id,
+			.flags = info->flags,
+			.size_in = send_cmd->in.size,
+			.size_out = send_cmd->out.size,
+		},
+		.opcode = c->opcode
+	};
+
+	return 0;
+}
+
+/**
+ * cxl_validate_cmd_from_user() - Check fields for CXL_MEM_SEND_COMMAND.
+ * @mbox_cmd: Sanitized and populated &struct cxl_mbox_cmd.
+ * @cxlds: The device data for the operation
+ * @send_cmd: &struct cxl_send_command copied in from userspace.
+ *
+ * Return:
+ *  * %0	- @out_cmd is ready to send.
+ *  * %-ENOTTY	- Invalid command specified.
+ *  * %-EINVAL	- Reserved fields or invalid values were used.
+ *  * %-ENOMEM	- Input or output buffer wasn't sized properly.
+ *  * %-EPERM	- Attempted to use a protected command.
+ *  * %-EBUSY	- Kernel has claimed exclusive access to this opcode
+ *
+ * The result of this command is a fully validated command in @mbox_cmd that is
+ * safe to send to the hardware.
+ */
+static int cxl_validate_cmd_from_user(struct cxl_mbox_cmd *mbox_cmd,
+				      struct cxl_dev_state *cxlds,
+				      const struct cxl_send_command *send_cmd)
+{
+	struct cxl_mem_command mem_cmd;
+	int rc;
+
+	if (send_cmd->id == 0 || send_cmd->id >= CXL_MEM_COMMAND_ID_MAX)
+		return -ENOTTY;
+
+	/*
+	 * The user can never specify an input payload larger than what hardware
+	 * supports, but output can be arbitrarily large (simply write out as
+	 * much data as the hardware provides).
+	 */
+	if (send_cmd->in.size > cxlds->payload_size)
+		return -EINVAL;
+
+	/* Sanitize and construct a cxl_mem_command */
+	if (send_cmd->id == CXL_MEM_COMMAND_ID_RAW)
+		rc = cxl_to_mem_cmd_raw(&mem_cmd, send_cmd, cxlds);
+	else
+		rc = cxl_to_mem_cmd(&mem_cmd, send_cmd, cxlds);
+
+	if (rc)
+		return rc;
+
+	/* Sanitize and construct a cxl_mbox_cmd */
+	return cxl_mbox_cmd_ctor(mbox_cmd, cxlds, mem_cmd.opcode,
+				 mem_cmd.info.size_in, mem_cmd.info.size_out,
+				 send_cmd->in.payload);
+}
+
+int cxl_query_cmd(struct cxl_memdev *cxlmd,
+		  struct cxl_mem_query_commands __user *q)
+{
+	struct device *dev = &cxlmd->dev;
+	struct cxl_mem_command *cmd;
+	u32 n_commands;
+	int j = 0;
+
+	dev_dbg(dev, "Query IOCTL\n");
+
+	if (get_user(n_commands, &q->n_commands))
+		return -EFAULT;
+
+	/* returns the total number if 0 elements are requested. */
+	if (n_commands == 0)
+		return put_user(ARRAY_SIZE(cxl_mem_commands), &q->n_commands);
+
+	/*
+	 * otherwise, return max(n_commands, total commands) cxl_command_info
+	 * structures.
+	 */
+	cxl_for_each_cmd(cmd) {
+		const struct cxl_command_info *info = &cmd->info;
+
+		if (copy_to_user(&q->commands[j++], info, sizeof(*info)))
+			return -EFAULT;
+
+		if (j == n_commands)
+			break;
+	}
+
+	return 0;
+}
+
+/**
+ * handle_mailbox_cmd_from_user() - Dispatch a mailbox command for userspace.
+ * @cxlds: The device data for the operation
+ * @mbox_cmd: The validated mailbox command.
+ * @out_payload: Pointer to userspace's output payload.
+ * @size_out: (Input) Max payload size to copy out.
+ *            (Output) Payload size hardware generated.
+ * @retval: Hardware generated return code from the operation.
+ *
+ * Return:
+ *  * %0	- Mailbox transaction succeeded. This implies the mailbox
+ *		  protocol completed successfully not that the operation itself
+ *		  was successful.
+ *  * %-ENOMEM  - Couldn't allocate a bounce buffer.
+ *  * %-EFAULT	- Something happened with copy_to/from_user.
+ *  * %-EINTR	- Mailbox acquisition interrupted.
+ *  * %-EXXX	- Transaction level failures.
+ *
+ * Dispatches a mailbox command on behalf of a userspace request.
+ * The output payload is copied to userspace.
+ *
+ * See cxl_send_cmd().
+ */
+static int handle_mailbox_cmd_from_user(struct cxl_dev_state *cxlds,
+					struct cxl_mbox_cmd *mbox_cmd,
+					u64 out_payload, s32 *size_out,
+					u32 *retval)
+{
+	struct device *dev = cxlds->dev;
+	int rc;
+
+	dev_dbg(dev,
+		"Submitting %s command for user\n"
+		"\topcode: %x\n"
+		"\tsize: %zx\n",
+		cxl_mem_opcode_to_name(mbox_cmd->opcode),
+		mbox_cmd->opcode, mbox_cmd->size_in);
+
+	rc = cxlds->mbox_send(cxlds, mbox_cmd);
+	if (rc)
+		goto out;
+
+	/*
+	 * @size_out contains the max size that's allowed to be written back out
+	 * to userspace. While the payload may have written more output than
+	 * this it will have to be ignored.
+	 */
+	if (mbox_cmd->size_out) {
+		dev_WARN_ONCE(dev, mbox_cmd->size_out > *size_out,
+			      "Invalid return size\n");
+		if (copy_to_user(u64_to_user_ptr(out_payload),
+				 mbox_cmd->payload_out, mbox_cmd->size_out)) {
+			rc = -EFAULT;
+			goto out;
+		}
+	}
+
+	*size_out = mbox_cmd->size_out;
+	*retval = mbox_cmd->return_code;
+
+out:
+	cxl_mbox_cmd_dtor(mbox_cmd);
+	return rc;
+}
+
+int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	struct device *dev = &cxlmd->dev;
+	struct cxl_send_command send;
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	dev_dbg(dev, "Send IOCTL\n");
+
+	if (copy_from_user(&send, s, sizeof(send)))
+		return -EFAULT;
+
+	rc = cxl_validate_cmd_from_user(&mbox_cmd, cxlmd->cxlds, &send);
+	if (rc)
+		return rc;
+
+	rc = handle_mailbox_cmd_from_user(cxlds, &mbox_cmd, send.out.payload,
+					  &send.out.size, &send.retval);
+	if (rc)
+		return rc;
+
+	if (copy_to_user(s, &send, sizeof(send)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int cxl_xfer_log(struct cxl_dev_state *cxlds, uuid_t *uuid, u32 size, u8 *out)
+{
+	u32 remaining = size;
+	u32 offset = 0;
+
+	while (remaining) {
+		u32 xfer_size = min_t(u32, remaining, cxlds->payload_size);
+		struct cxl_mbox_cmd mbox_cmd;
+		struct cxl_mbox_get_log log;
+		int rc;
+
+		log = (struct cxl_mbox_get_log) {
+			.uuid = *uuid,
+			.offset = cpu_to_le32(offset),
+			.length = cpu_to_le32(xfer_size),
+		};
+
+		mbox_cmd = (struct cxl_mbox_cmd) {
+			.opcode = CXL_MBOX_OP_GET_LOG,
+			.size_in = sizeof(log),
+			.payload_in = &log,
+			.size_out = xfer_size,
+			.payload_out = out,
+		};
+
+		rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+		if (rc < 0)
+			return rc;
+
+		out += xfer_size;
+		remaining -= xfer_size;
+		offset += xfer_size;
+	}
+
+	return 0;
+}
+
+/**
+ * cxl_walk_cel() - Walk through the Command Effects Log.
+ * @cxlds: The device data for the operation
+ * @size: Length of the Command Effects Log.
+ * @cel: CEL
+ *
+ * Iterate over each entry in the CEL and determine if the driver supports the
+ * command. If so, the command is enabled for the device and can be used later.
+ */
+static void cxl_walk_cel(struct cxl_dev_state *cxlds, size_t size, u8 *cel)
+{
+	struct cxl_cel_entry *cel_entry;
+	const int cel_entries = size / sizeof(*cel_entry);
+	int i;
+
+	cel_entry = (struct cxl_cel_entry *) cel;
+
+	for (i = 0; i < cel_entries; i++) {
+		u16 opcode = le16_to_cpu(cel_entry[i].opcode);
+		struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
+
+		if (!cmd) {
+			dev_dbg(cxlds->dev,
+				"Opcode 0x%04x unsupported by driver", opcode);
+			continue;
+		}
+
+		set_bit(cmd->info.id, cxlds->enabled_cmds);
+	}
+}
+
+static struct cxl_mbox_get_supported_logs *cxl_get_gsl(struct cxl_dev_state *cxlds)
+{
+	struct cxl_mbox_get_supported_logs *ret;
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	ret = kvmalloc(cxlds->payload_size, GFP_KERNEL);
+	if (!ret)
+		return ERR_PTR(-ENOMEM);
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_GET_SUPPORTED_LOGS,
+		.size_out = cxlds->payload_size,
+		.payload_out = ret,
+		/* At least the record number field must be valid */
+		.min_out = 2,
+	};
+	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+	if (rc < 0) {
+		kvfree(ret);
+		return ERR_PTR(rc);
+	}
+
+
+	return ret;
+}
+
+enum {
+	CEL_UUID,
+	VENDOR_DEBUG_UUID,
+};
+
+/* See CXL 2.0 Table 170. Get Log Input Payload */
+static const uuid_t log_uuid[] = {
+	[CEL_UUID] = DEFINE_CXL_CEL_UUID,
+	[VENDOR_DEBUG_UUID] = DEFINE_CXL_VENDOR_DEBUG_UUID,
+};
+
+/**
+ * cxl_enumerate_cmds() - Enumerate commands for a device.
+ * @cxlds: The device data for the operation
+ *
+ * Returns 0 if enumerate completed successfully.
+ *
+ * CXL devices have optional support for certain commands. This function will
+ * determine the set of supported commands for the hardware and update the
+ * enabled_cmds bitmap in the @cxlds.
+ */
+int cxl_enumerate_cmds(struct cxl_dev_state *cxlds)
+{
+	struct cxl_mbox_get_supported_logs *gsl;
+	struct device *dev = cxlds->dev;
+	struct cxl_mem_command *cmd;
+	int i, rc;
+
+	gsl = cxl_get_gsl(cxlds);
+	if (IS_ERR(gsl))
+		return PTR_ERR(gsl);
+
+	rc = -ENOENT;
+	for (i = 0; i < le16_to_cpu(gsl->entries); i++) {
+		u32 size = le32_to_cpu(gsl->entry[i].size);
+		uuid_t uuid = gsl->entry[i].uuid;
+		u8 *log;
+
+		dev_dbg(dev, "Found LOG type %pU of size %d", &uuid, size);
+
+		if (!uuid_equal(&uuid, &log_uuid[CEL_UUID]))
+			continue;
+
+		log = kvmalloc(size, GFP_KERNEL);
+		if (!log) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		rc = cxl_xfer_log(cxlds, &uuid, size, log);
+		if (rc) {
+			kvfree(log);
+			goto out;
+		}
+
+		cxl_walk_cel(cxlds, size, log);
+		kvfree(log);
+
+		/* In case CEL was bogus, enable some default commands. */
+		cxl_for_each_cmd(cmd)
+			if (cmd->flags & CXL_CMD_FLAG_FORCE_ENABLE)
+				set_bit(cmd->info.id, cxlds->enabled_cmds);
+
+		/* Found the required CEL */
+		rc = 0;
+	}
+out:
+	kvfree(gsl);
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_enumerate_cmds, CXL);
+
+/**
+ * cxl_mem_get_partition_info - Get partition info
+ * @cxlds: The device data for the operation
+ *
+ * Retrieve the current partition info for the device specified.  The active
+ * values are the current capacity in bytes.  If not 0, the 'next' values are
+ * the pending values, in bytes, which take affect on next cold reset.
+ *
+ * Return: 0 if no error: or the result of the mailbox command.
+ *
+ * See CXL @8.2.9.5.2.1 Get Partition Info
+ */
+static int cxl_mem_get_partition_info(struct cxl_dev_state *cxlds)
+{
+	struct cxl_mbox_get_partition_info pi;
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_GET_PARTITION_INFO,
+		.size_out = sizeof(pi),
+		.payload_out = &pi,
+	};
+	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+	if (rc)
+		return rc;
+
+	cxlds->active_volatile_bytes =
+		le64_to_cpu(pi.active_volatile_cap) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->active_persistent_bytes =
+		le64_to_cpu(pi.active_persistent_cap) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->next_volatile_bytes =
+		le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->next_persistent_bytes =
+		le64_to_cpu(pi.next_volatile_cap) * CXL_CAPACITY_MULTIPLIER;
+
+	return 0;
+}
+
+/**
+ * cxl_dev_state_identify() - Send the IDENTIFY command to the device.
+ * @cxlds: The device data for the operation
+ *
+ * Return: 0 if identify was executed successfully.
+ *
+ * This will dispatch the identify command to the device and on success populate
+ * structures to be exported to sysfs.
+ */
+int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
+{
+	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
+	struct cxl_mbox_identify id;
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_IDENTIFY,
+		.size_out = sizeof(id),
+		.payload_out = &id,
+	};
+	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
+	if (rc < 0)
+		return rc;
+
+	cxlds->total_bytes =
+		le64_to_cpu(id.total_capacity) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->volatile_only_bytes =
+		le64_to_cpu(id.volatile_capacity) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->persistent_only_bytes =
+		le64_to_cpu(id.persistent_capacity) * CXL_CAPACITY_MULTIPLIER;
+	cxlds->partition_align_bytes =
+		le64_to_cpu(id.partition_align) * CXL_CAPACITY_MULTIPLIER;
+
+	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
+	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
+
+static int add_dpa_res(struct device *dev, struct resource *parent,
+		       struct resource *res, resource_size_t start,
+		       resource_size_t size, const char *type)
+{
+	int rc;
+
+	res->name = type;
+	res->start = start;
+	res->end = start + size - 1;
+	res->flags = IORESOURCE_MEM;
+	if (resource_size(res) == 0) {
+		dev_dbg(dev, "DPA(%s): no capacity\n", res->name);
+		return 0;
+	}
+	rc = request_resource(parent, res);
+	if (rc) {
+		dev_err(dev, "DPA(%s): failed to track %pr (%d)\n", res->name,
+			res, rc);
+		return rc;
+	}
+
+	dev_dbg(dev, "DPA(%s): %pr\n", res->name, res);
+
+	return 0;
+}
+
+int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
+{
+	struct device *dev = cxlds->dev;
+	int rc;
+
+	cxlds->dpa_res =
+		(struct resource)DEFINE_RES_MEM(0, cxlds->total_bytes);
+
+	if (cxlds->partition_align_bytes == 0) {
+		rc = add_dpa_res(dev, &cxlds->dpa_res, &cxlds->ram_res, 0,
+				 cxlds->volatile_only_bytes, "ram");
+		if (rc)
+			return rc;
+		return add_dpa_res(dev, &cxlds->dpa_res, &cxlds->pmem_res,
+				   cxlds->volatile_only_bytes,
+				   cxlds->persistent_only_bytes, "pmem");
+	}
+
+	rc = cxl_mem_get_partition_info(cxlds);
+	if (rc) {
+		dev_err(dev, "Failed to query partition information\n");
+		return rc;
+	}
+
+	rc = add_dpa_res(dev, &cxlds->dpa_res, &cxlds->ram_res, 0,
+			 cxlds->active_volatile_bytes, "ram");
+	if (rc)
+		return rc;
+	return add_dpa_res(dev, &cxlds->dpa_res, &cxlds->pmem_res,
+			   cxlds->active_volatile_bytes,
+			   cxlds->active_persistent_bytes, "pmem");
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL);
+
+struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
+{
+	struct cxl_dev_state *cxlds;
+
+	cxlds = devm_kzalloc(dev, sizeof(*cxlds), GFP_KERNEL);
+	if (!cxlds) {
+		dev_err(dev, "No memory available\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	mutex_init(&cxlds->mbox_mutex);
+	cxlds->dev = dev;
+
+	return cxlds;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_dev_state_create, CXL);
+
+void __init cxl_mbox_init(void)
+{
+	struct dentry *mbox_debugfs;
+
+	mbox_debugfs = cxl_debugfs_create_dir("mbox");
+	debugfs_create_bool("raw_allow_all", 0600, mbox_debugfs,
+			    &cxl_raw_allow_all);
+}