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, 766 insertions, 0 deletions

diff --git a/drivers/fsi/fsi-occ.c b/drivers/fsi/fsi-occ.c
new file mode 100644
index 000000000..abdd37d55
--- /dev/null
+++ b/drivers/fsi/fsi-occ.c
@@ -0,0 +1,766 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fsi-sbefifo.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/fsi-occ.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <asm/unaligned.h>
+
+#define OCC_SRAM_BYTES		4096
+#define OCC_CMD_DATA_BYTES	4090
+#define OCC_RESP_DATA_BYTES	4089
+
+#define OCC_P9_SRAM_CMD_ADDR	0xFFFBE000
+#define OCC_P9_SRAM_RSP_ADDR	0xFFFBF000
+
+#define OCC_P10_SRAM_CMD_ADDR	0xFFFFD000
+#define OCC_P10_SRAM_RSP_ADDR	0xFFFFE000
+
+#define OCC_P10_SRAM_MODE	0x58	/* Normal mode, OCB channel 2 */
+
+#define OCC_TIMEOUT_MS		1000
+#define OCC_CMD_IN_PRG_WAIT_MS	50
+
+enum versions { occ_p9, occ_p10 };
+
+struct occ {
+	struct device *dev;
+	struct device *sbefifo;
+	char name[32];
+	int idx;
+	bool platform_hwmon;
+	u8 sequence_number;
+	void *buffer;
+	void *client_buffer;
+	size_t client_buffer_size;
+	size_t client_response_size;
+	enum versions version;
+	struct miscdevice mdev;
+	struct mutex occ_lock;
+};
+
+#define to_occ(x)	container_of((x), struct occ, mdev)
+
+struct occ_response {
+	u8 seq_no;
+	u8 cmd_type;
+	u8 return_status;
+	__be16 data_length;
+	u8 data[OCC_RESP_DATA_BYTES + 2];	/* two bytes checksum */
+} __packed;
+
+struct occ_client {
+	struct occ *occ;
+	struct mutex lock;
+	size_t data_size;
+	size_t read_offset;
+	u8 *buffer;
+};
+
+#define to_client(x)	container_of((x), struct occ_client, xfr)
+
+static DEFINE_IDA(occ_ida);
+
+static int occ_open(struct inode *inode, struct file *file)
+{
+	struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
+	struct miscdevice *mdev = file->private_data;
+	struct occ *occ = to_occ(mdev);
+
+	if (!client)
+		return -ENOMEM;
+
+	client->buffer = (u8 *)__get_free_page(GFP_KERNEL);
+	if (!client->buffer) {
+		kfree(client);
+		return -ENOMEM;
+	}
+
+	client->occ = occ;
+	mutex_init(&client->lock);
+	file->private_data = client;
+	get_device(occ->dev);
+
+	/* We allocate a 1-page buffer, make sure it all fits */
+	BUILD_BUG_ON((OCC_CMD_DATA_BYTES + 3) > PAGE_SIZE);
+	BUILD_BUG_ON((OCC_RESP_DATA_BYTES + 7) > PAGE_SIZE);
+
+	return 0;
+}
+
+static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
+			loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+	ssize_t rc = 0;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > OCC_SRAM_BYTES)
+		return -EINVAL;
+
+	mutex_lock(&client->lock);
+
+	/* This should not be possible ... */
+	if (WARN_ON_ONCE(client->read_offset > client->data_size)) {
+		rc = -EIO;
+		goto done;
+	}
+
+	/* Grab how much data we have to read */
+	rc = min(len, client->data_size - client->read_offset);
+	if (copy_to_user(buf, client->buffer + client->read_offset, rc))
+		rc = -EFAULT;
+	else
+		client->read_offset += rc;
+
+ done:
+	mutex_unlock(&client->lock);
+
+	return rc;
+}
+
+static ssize_t occ_write(struct file *file, const char __user *buf,
+			 size_t len, loff_t *offset)
+{
+	struct occ_client *client = file->private_data;
+	size_t rlen, data_length;
+	ssize_t rc;
+	u8 *cmd;
+
+	if (!client)
+		return -ENODEV;
+
+	if (len > (OCC_CMD_DATA_BYTES + 3) || len < 3)
+		return -EINVAL;
+
+	mutex_lock(&client->lock);
+
+	/* Construct the command */
+	cmd = client->buffer;
+
+	/*
+	 * Copy the user command (assume user data follows the occ command
+	 * format)
+	 * byte 0: command type
+	 * bytes 1-2: data length (msb first)
+	 * bytes 3-n: data
+	 */
+	if (copy_from_user(&cmd[1], buf, len)) {
+		rc = -EFAULT;
+		goto done;
+	}
+
+	/* Extract data length */
+	data_length = (cmd[2] << 8) + cmd[3];
+	if (data_length > OCC_CMD_DATA_BYTES) {
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Submit command; 4 bytes before the data and 2 bytes after */
+	rlen = PAGE_SIZE;
+	rc = fsi_occ_submit(client->occ->dev, cmd, data_length + 6, cmd,
+			    &rlen);
+	if (rc)
+		goto done;
+
+	/* Set read tracking data */
+	client->data_size = rlen;
+	client->read_offset = 0;
+
+	/* Done */
+	rc = len;
+
+ done:
+	mutex_unlock(&client->lock);
+
+	return rc;
+}
+
+static int occ_release(struct inode *inode, struct file *file)
+{
+	struct occ_client *client = file->private_data;
+
+	put_device(client->occ->dev);
+	free_page((unsigned long)client->buffer);
+	kfree(client);
+
+	return 0;
+}
+
+static const struct file_operations occ_fops = {
+	.owner = THIS_MODULE,
+	.open = occ_open,
+	.read = occ_read,
+	.write = occ_write,
+	.release = occ_release,
+};
+
+static void occ_save_ffdc(struct occ *occ, __be32 *resp, size_t parsed_len,
+			  size_t resp_len)
+{
+	if (resp_len > parsed_len) {
+		size_t dh = resp_len - parsed_len;
+		size_t ffdc_len = (dh - 1) * 4; /* SBE words are four bytes */
+		__be32 *ffdc = &resp[parsed_len];
+
+		if (ffdc_len > occ->client_buffer_size)
+			ffdc_len = occ->client_buffer_size;
+
+		memcpy(occ->client_buffer, ffdc, ffdc_len);
+		occ->client_response_size = ffdc_len;
+	}
+}
+
+static int occ_verify_checksum(struct occ *occ, struct occ_response *resp,
+			       u16 data_length)
+{
+	/* Fetch the two bytes after the data for the checksum. */
+	u16 checksum_resp = get_unaligned_be16(&resp->data[data_length]);
+	u16 checksum;
+	u16 i;
+
+	checksum = resp->seq_no;
+	checksum += resp->cmd_type;
+	checksum += resp->return_status;
+	checksum += (data_length >> 8) + (data_length & 0xFF);
+
+	for (i = 0; i < data_length; ++i)
+		checksum += resp->data[i];
+
+	if (checksum != checksum_resp) {
+		dev_err(occ->dev, "Bad checksum: %04x!=%04x\n", checksum,
+			checksum_resp);
+		return -EBADE;
+	}
+
+	return 0;
+}
+
+static int occ_getsram(struct occ *occ, u32 offset, void *data, ssize_t len)
+{
+	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
+	size_t cmd_len, parsed_len, resp_data_len;
+	size_t resp_len = OCC_MAX_RESP_WORDS;
+	__be32 *resp = occ->buffer;
+	__be32 cmd[6];
+	int idx = 0, rc;
+
+	/*
+	 * Magic sequence to do SBE getsram command. SBE will fetch data from
+	 * specified SRAM address.
+	 */
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		cmd_len = 5;
+		cmd[2] = cpu_to_be32(1);	/* Normal mode */
+		cmd[3] = cpu_to_be32(OCC_P9_SRAM_RSP_ADDR + offset);
+		break;
+	case occ_p10:
+		idx = 1;
+		cmd_len = 6;
+		cmd[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
+		cmd[3] = 0;
+		cmd[4] = cpu_to_be32(OCC_P10_SRAM_RSP_ADDR + offset);
+		break;
+	}
+
+	cmd[0] = cpu_to_be32(cmd_len);
+	cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_OCC_SRAM);
+	cmd[4 + idx] = cpu_to_be32(data_len);
+
+	rc = sbefifo_submit(occ->sbefifo, cmd, cmd_len, resp, &resp_len);
+	if (rc)
+		return rc;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_GET_OCC_SRAM,
+				  resp, resp_len, &parsed_len);
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM read returned failure status: %08x\n",
+			rc);
+		occ_save_ffdc(occ, resp, parsed_len, resp_len);
+		return -ECOMM;
+	} else if (rc) {
+		return rc;
+	}
+
+	resp_data_len = be32_to_cpu(resp[parsed_len - 1]);
+	if (resp_data_len != data_len) {
+		dev_err(occ->dev, "SRAM read expected %d bytes got %zd\n",
+			data_len, resp_data_len);
+		rc = -EBADMSG;
+	} else {
+		memcpy(data, resp, len);
+	}
+
+	return rc;
+}
+
+static int occ_putsram(struct occ *occ, const void *data, ssize_t len,
+		       u8 seq_no, u16 checksum)
+{
+	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
+	size_t cmd_len, parsed_len, resp_data_len;
+	size_t resp_len = OCC_MAX_RESP_WORDS;
+	__be32 *buf = occ->buffer;
+	u8 *byte_buf;
+	int idx = 0, rc;
+
+	cmd_len = (occ->version == occ_p10) ? 6 : 5;
+	cmd_len += data_len >> 2;
+
+	/*
+	 * Magic sequence to do SBE putsram command. SBE will transfer
+	 * data to specified SRAM address.
+	 */
+	buf[0] = cpu_to_be32(cmd_len);
+	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
+
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		buf[2] = cpu_to_be32(1);	/* Normal mode */
+		buf[3] = cpu_to_be32(OCC_P9_SRAM_CMD_ADDR);
+		break;
+	case occ_p10:
+		idx = 1;
+		buf[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
+		buf[3] = 0;
+		buf[4] = cpu_to_be32(OCC_P10_SRAM_CMD_ADDR);
+		break;
+	}
+
+	buf[4 + idx] = cpu_to_be32(data_len);
+	memcpy(&buf[5 + idx], data, len);
+
+	byte_buf = (u8 *)&buf[5 + idx];
+	/*
+	 * Overwrite the first byte with our sequence number and the last two
+	 * bytes with the checksum.
+	 */
+	byte_buf[0] = seq_no;
+	byte_buf[len - 2] = checksum >> 8;
+	byte_buf[len - 1] = checksum & 0xff;
+
+	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
+	if (rc)
+		return rc;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
+				  buf, resp_len, &parsed_len);
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM write returned failure status: %08x\n",
+			rc);
+		occ_save_ffdc(occ, buf, parsed_len, resp_len);
+		return -ECOMM;
+	} else if (rc) {
+		return rc;
+	}
+
+	if (parsed_len != 1) {
+		dev_err(occ->dev, "SRAM write response length invalid: %zd\n",
+			parsed_len);
+		rc = -EBADMSG;
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != data_len) {
+			dev_err(occ->dev,
+				"SRAM write expected %d bytes got %zd\n",
+				data_len, resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
+
+	return rc;
+}
+
+static int occ_trigger_attn(struct occ *occ)
+{
+	__be32 *buf = occ->buffer;
+	size_t cmd_len, parsed_len, resp_data_len;
+	size_t resp_len = OCC_MAX_RESP_WORDS;
+	int idx = 0, rc;
+
+	switch (occ->version) {
+	default:
+	case occ_p9:
+		cmd_len = 7;
+		buf[2] = cpu_to_be32(3); /* Circular mode */
+		buf[3] = 0;
+		break;
+	case occ_p10:
+		idx = 1;
+		cmd_len = 8;
+		buf[2] = cpu_to_be32(0xd0); /* Circular mode, OCB Channel 1 */
+		buf[3] = 0;
+		buf[4] = 0;
+		break;
+	}
+
+	buf[0] = cpu_to_be32(cmd_len);		/* Chip-op length in words */
+	buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
+	buf[4 + idx] = cpu_to_be32(8);		/* Data length in bytes */
+	buf[5 + idx] = cpu_to_be32(0x20010000);	/* Trigger OCC attention */
+	buf[6 + idx] = 0;
+
+	rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
+	if (rc)
+		return rc;
+
+	rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
+				  buf, resp_len, &parsed_len);
+	if (rc > 0) {
+		dev_err(occ->dev, "SRAM attn returned failure status: %08x\n",
+			rc);
+		occ_save_ffdc(occ, buf, parsed_len, resp_len);
+		return -ECOMM;
+	} else if (rc) {
+		return rc;
+	}
+
+	if (parsed_len != 1) {
+		dev_err(occ->dev, "SRAM attn response length invalid: %zd\n",
+			parsed_len);
+		rc = -EBADMSG;
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != 8) {
+			dev_err(occ->dev,
+				"SRAM attn expected 8 bytes got %zd\n",
+				resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
+
+	return rc;
+}
+
+static bool fsi_occ_response_not_ready(struct occ_response *resp, u8 seq_no,
+				       u8 cmd_type)
+{
+	return resp->return_status == OCC_RESP_CMD_IN_PRG ||
+		resp->return_status == OCC_RESP_CRIT_INIT ||
+		resp->seq_no != seq_no || resp->cmd_type != cmd_type;
+}
+
+int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
+		   void *response, size_t *resp_len)
+{
+	const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS);
+	const unsigned long wait_time =
+		msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
+	struct occ *occ = dev_get_drvdata(dev);
+	struct occ_response *resp = response;
+	size_t user_resp_len = *resp_len;
+	u8 seq_no;
+	u8 cmd_type;
+	u16 checksum = 0;
+	u16 resp_data_length;
+	const u8 *byte_request = (const u8 *)request;
+	unsigned long end;
+	int rc;
+	size_t i;
+
+	*resp_len = 0;
+
+	if (!occ)
+		return -ENODEV;
+
+	if (user_resp_len < 7) {
+		dev_dbg(dev, "Bad resplen %zd\n", user_resp_len);
+		return -EINVAL;
+	}
+
+	cmd_type = byte_request[1];
+
+	/* Checksum the request, ignoring first byte (sequence number). */
+	for (i = 1; i < req_len - 2; ++i)
+		checksum += byte_request[i];
+
+	rc = mutex_lock_interruptible(&occ->occ_lock);
+	if (rc)
+		return rc;
+
+	occ->client_buffer = response;
+	occ->client_buffer_size = user_resp_len;
+	occ->client_response_size = 0;
+
+	if (!occ->buffer) {
+		rc = -ENOENT;
+		goto done;
+	}
+
+	/*
+	 * Get a sequence number and update the counter. Avoid a sequence
+	 * number of 0 which would pass the response check below even if the
+	 * OCC response is uninitialized. Any sequence number the user is
+	 * trying to send is overwritten since this function is the only common
+	 * interface to the OCC and therefore the only place we can guarantee
+	 * unique sequence numbers.
+	 */
+	seq_no = occ->sequence_number++;
+	if (!occ->sequence_number)
+		occ->sequence_number = 1;
+	checksum += seq_no;
+
+	rc = occ_putsram(occ, request, req_len, seq_no, checksum);
+	if (rc)
+		goto done;
+
+	rc = occ_trigger_attn(occ);
+	if (rc)
+		goto done;
+
+	end = jiffies + timeout;
+	while (true) {
+		/* Read occ response header */
+		rc = occ_getsram(occ, 0, resp, 8);
+		if (rc)
+			goto done;
+
+		if (fsi_occ_response_not_ready(resp, seq_no, cmd_type)) {
+			if (time_after(jiffies, end)) {
+				dev_err(occ->dev,
+					"resp timeout status=%02x seq=%d cmd=%d, our seq=%d cmd=%d\n",
+					resp->return_status, resp->seq_no,
+					resp->cmd_type, seq_no, cmd_type);
+				rc = -ETIMEDOUT;
+				goto done;
+			}
+
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(wait_time);
+		} else {
+			/* Extract size of response data */
+			resp_data_length =
+				get_unaligned_be16(&resp->data_length);
+
+			/*
+			 * Message size is data length + 5 bytes header + 2
+			 * bytes checksum
+			 */
+			if ((resp_data_length + 7) > user_resp_len) {
+				rc = -EMSGSIZE;
+				goto done;
+			}
+
+			/*
+			 * Get the entire response including the header again,
+			 * in case it changed
+			 */
+			if (resp_data_length > 1) {
+				rc = occ_getsram(occ, 0, resp,
+						 resp_data_length + 7);
+				if (rc)
+					goto done;
+
+				if (!fsi_occ_response_not_ready(resp, seq_no,
+								cmd_type))
+					break;
+			} else {
+				break;
+			}
+		}
+	}
+
+	dev_dbg(dev, "resp_status=%02x resp_data_len=%d\n",
+		resp->return_status, resp_data_length);
+
+	rc = occ_verify_checksum(occ, resp, resp_data_length);
+	if (rc)
+		goto done;
+
+	occ->client_response_size = resp_data_length + 7;
+
+ done:
+	*resp_len = occ->client_response_size;
+	mutex_unlock(&occ->occ_lock);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(fsi_occ_submit);
+
+static int occ_unregister_platform_child(struct device *dev, void *data)
+{
+	struct platform_device *hwmon_dev = to_platform_device(dev);
+
+	platform_device_unregister(hwmon_dev);
+
+	return 0;
+}
+
+static int occ_unregister_of_child(struct device *dev, void *data)
+{
+	struct platform_device *hwmon_dev = to_platform_device(dev);
+
+	of_device_unregister(hwmon_dev);
+	if (dev->of_node)
+		of_node_clear_flag(dev->of_node, OF_POPULATED);
+
+	return 0;
+}
+
+static int occ_probe(struct platform_device *pdev)
+{
+	int rc;
+	u32 reg;
+	char child_name[32];
+	struct occ *occ;
+	struct platform_device *hwmon_dev = NULL;
+	struct device_node *hwmon_node;
+	struct device *dev = &pdev->dev;
+	struct platform_device_info hwmon_dev_info = {
+		.parent = dev,
+		.name = "occ-hwmon",
+	};
+
+	occ = devm_kzalloc(dev, sizeof(*occ), GFP_KERNEL);
+	if (!occ)
+		return -ENOMEM;
+
+	/* SBE words are always four bytes */
+	occ->buffer = kvmalloc(OCC_MAX_RESP_WORDS * 4, GFP_KERNEL);
+	if (!occ->buffer)
+		return -ENOMEM;
+
+	occ->version = (uintptr_t)of_device_get_match_data(dev);
+	occ->dev = dev;
+	occ->sbefifo = dev->parent;
+	/*
+	 * Quickly derive a pseudo-random number from jiffies so that
+	 * re-probing the driver doesn't accidentally overlap sequence numbers.
+	 */
+	occ->sequence_number = (u8)((jiffies % 0xff) + 1);
+	mutex_init(&occ->occ_lock);
+
+	if (dev->of_node) {
+		rc = of_property_read_u32(dev->of_node, "reg", &reg);
+		if (!rc) {
+			/* make sure we don't have a duplicate from dts */
+			occ->idx = ida_simple_get(&occ_ida, reg, reg + 1,
+						  GFP_KERNEL);
+			if (occ->idx < 0)
+				occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
+							  GFP_KERNEL);
+		} else {
+			occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
+						  GFP_KERNEL);
+		}
+	} else {
+		occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL);
+	}
+
+	platform_set_drvdata(pdev, occ);
+
+	snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx);
+	occ->mdev.fops = &occ_fops;
+	occ->mdev.minor = MISC_DYNAMIC_MINOR;
+	occ->mdev.name = occ->name;
+	occ->mdev.parent = dev;
+
+	rc = misc_register(&occ->mdev);
+	if (rc) {
+		dev_err(dev, "failed to register miscdevice: %d\n", rc);
+		ida_simple_remove(&occ_ida, occ->idx);
+		kvfree(occ->buffer);
+		return rc;
+	}
+
+	hwmon_node = of_get_child_by_name(dev->of_node, hwmon_dev_info.name);
+	if (hwmon_node) {
+		snprintf(child_name, sizeof(child_name), "%s.%d", hwmon_dev_info.name, occ->idx);
+		hwmon_dev = of_platform_device_create(hwmon_node, child_name, dev);
+		of_node_put(hwmon_node);
+	}
+
+	if (!hwmon_dev) {
+		occ->platform_hwmon = true;
+		hwmon_dev_info.id = occ->idx;
+		hwmon_dev = platform_device_register_full(&hwmon_dev_info);
+		if (IS_ERR(hwmon_dev))
+			dev_warn(dev, "failed to create hwmon device\n");
+	}
+
+	return 0;
+}
+
+static int occ_remove(struct platform_device *pdev)
+{
+	struct occ *occ = platform_get_drvdata(pdev);
+
+	misc_deregister(&occ->mdev);
+
+	mutex_lock(&occ->occ_lock);
+	kvfree(occ->buffer);
+	occ->buffer = NULL;
+	mutex_unlock(&occ->occ_lock);
+
+	if (occ->platform_hwmon)
+		device_for_each_child(&pdev->dev, NULL, occ_unregister_platform_child);
+	else
+		device_for_each_child(&pdev->dev, NULL, occ_unregister_of_child);
+
+	ida_simple_remove(&occ_ida, occ->idx);
+
+	return 0;
+}
+
+static const struct of_device_id occ_match[] = {
+	{
+		.compatible = "ibm,p9-occ",
+		.data = (void *)occ_p9
+	},
+	{
+		.compatible = "ibm,p10-occ",
+		.data = (void *)occ_p10
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, occ_match);
+
+static struct platform_driver occ_driver = {
+	.driver = {
+		.name = "occ",
+		.of_match_table	= occ_match,
+	},
+	.probe	= occ_probe,
+	.remove = occ_remove,
+};
+
+static int occ_init(void)
+{
+	return platform_driver_register(&occ_driver);
+}
+
+static void occ_exit(void)
+{
+	platform_driver_unregister(&occ_driver);
+
+	ida_destroy(&occ_ida);
+}
+
+module_init(occ_init);
+module_exit(occ_exit);
+
+MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
+MODULE_DESCRIPTION("BMC P9 OCC driver");
+MODULE_LICENSE("GPL");