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, 444 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/wil6210/pmc.c b/drivers/net/wireless/ath/wil6210/pmc.c
new file mode 100644
index 000000000..a2f7b4c1d
--- /dev/null
+++ b/drivers/net/wireless/ath/wil6210/pmc.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2012-2015,2017 Qualcomm Atheros, Inc.
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include "wmi.h"
+#include "wil6210.h"
+#include "txrx.h"
+#include "pmc.h"
+
+struct desc_alloc_info {
+	dma_addr_t pa;
+	void	  *va;
+};
+
+static int wil_is_pmc_allocated(struct pmc_ctx *pmc)
+{
+	return !!pmc->pring_va;
+}
+
+void wil_pmc_init(struct wil6210_priv *wil)
+{
+	memset(&wil->pmc, 0, sizeof(struct pmc_ctx));
+	mutex_init(&wil->pmc.lock);
+}
+
+/* Allocate the physical ring (p-ring) and the required
+ * number of descriptors of required size.
+ * Initialize the descriptors as required by pmc dma.
+ * The descriptors' buffers dwords are initialized to hold
+ * dword's serial number in the lsw and reserved value
+ * PCM_DATA_INVALID_DW_VAL in the msw.
+ */
+void wil_pmc_alloc(struct wil6210_priv *wil,
+		   int num_descriptors,
+		   int descriptor_size)
+{
+	u32 i;
+	struct pmc_ctx *pmc = &wil->pmc;
+	struct device *dev = wil_to_dev(wil);
+	struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
+	struct wmi_pmc_cmd pmc_cmd = {0};
+	int last_cmd_err = -ENOMEM;
+
+	mutex_lock(&pmc->lock);
+
+	if (wil_is_pmc_allocated(pmc)) {
+		/* sanity check */
+		wil_err(wil, "ERROR pmc is already allocated\n");
+		goto no_release_err;
+	}
+	if ((num_descriptors <= 0) || (descriptor_size <= 0)) {
+		wil_err(wil,
+			"Invalid params num_descriptors(%d), descriptor_size(%d)\n",
+			num_descriptors, descriptor_size);
+		last_cmd_err = -EINVAL;
+		goto no_release_err;
+	}
+
+	if (num_descriptors > (1 << WIL_RING_SIZE_ORDER_MAX)) {
+		wil_err(wil,
+			"num_descriptors(%d) exceeds max ring size %d\n",
+			num_descriptors, 1 << WIL_RING_SIZE_ORDER_MAX);
+		last_cmd_err = -EINVAL;
+		goto no_release_err;
+	}
+
+	if (num_descriptors > INT_MAX / descriptor_size) {
+		wil_err(wil,
+			"Overflow in num_descriptors(%d)*descriptor_size(%d)\n",
+			num_descriptors, descriptor_size);
+		last_cmd_err = -EINVAL;
+		goto no_release_err;
+	}
+
+	pmc->num_descriptors = num_descriptors;
+	pmc->descriptor_size = descriptor_size;
+
+	wil_dbg_misc(wil, "pmc_alloc: %d descriptors x %d bytes each\n",
+		     num_descriptors, descriptor_size);
+
+	/* allocate descriptors info list in pmc context*/
+	pmc->descriptors = kcalloc(num_descriptors,
+				  sizeof(struct desc_alloc_info),
+				  GFP_KERNEL);
+	if (!pmc->descriptors) {
+		wil_err(wil, "ERROR allocating pmc skb list\n");
+		goto no_release_err;
+	}
+
+	wil_dbg_misc(wil, "pmc_alloc: allocated descriptors info list %p\n",
+		     pmc->descriptors);
+
+	/* Allocate pring buffer and descriptors.
+	 * vring->va should be aligned on its size rounded up to power of 2
+	 * This is granted by the dma_alloc_coherent.
+	 *
+	 * HW has limitation that all vrings addresses must share the same
+	 * upper 16 msb bits part of 48 bits address. To workaround that,
+	 * if we are using more than 32 bit addresses switch to 32 bit
+	 * allocation before allocating vring memory.
+	 *
+	 * There's no check for the return value of dma_set_mask_and_coherent,
+	 * since we assume if we were able to set the mask during
+	 * initialization in this system it will not fail if we set it again
+	 */
+	if (wil->dma_addr_size > 32)
+		dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+
+	pmc->pring_va = dma_alloc_coherent(dev,
+			sizeof(struct vring_tx_desc) * num_descriptors,
+			&pmc->pring_pa,
+			GFP_KERNEL);
+
+	if (wil->dma_addr_size > 32)
+		dma_set_mask_and_coherent(dev,
+					  DMA_BIT_MASK(wil->dma_addr_size));
+
+	wil_dbg_misc(wil,
+		     "pmc_alloc: allocated pring %p => %pad. %zd x %d = total %zd bytes\n",
+		     pmc->pring_va, &pmc->pring_pa,
+		     sizeof(struct vring_tx_desc),
+		     num_descriptors,
+		     sizeof(struct vring_tx_desc) * num_descriptors);
+
+	if (!pmc->pring_va) {
+		wil_err(wil, "ERROR allocating pmc pring\n");
+		goto release_pmc_skb_list;
+	}
+
+	/* initially, all descriptors are SW owned
+	 * For Tx, Rx, and PMC, ownership bit is at the same location, thus
+	 * we can use any
+	 */
+	for (i = 0; i < num_descriptors; i++) {
+		struct vring_tx_desc *_d = &pmc->pring_va[i];
+		struct vring_tx_desc dd = {}, *d = &dd;
+		int j = 0;
+
+		pmc->descriptors[i].va = dma_alloc_coherent(dev,
+			descriptor_size,
+			&pmc->descriptors[i].pa,
+			GFP_KERNEL);
+
+		if (unlikely(!pmc->descriptors[i].va)) {
+			wil_err(wil, "ERROR allocating pmc descriptor %d", i);
+			goto release_pmc_skbs;
+		}
+
+		for (j = 0; j < descriptor_size / sizeof(u32); j++) {
+			u32 *p = (u32 *)pmc->descriptors[i].va + j;
+			*p = PCM_DATA_INVALID_DW_VAL | j;
+		}
+
+		/* configure dma descriptor */
+		d->dma.addr.addr_low =
+			cpu_to_le32(lower_32_bits(pmc->descriptors[i].pa));
+		d->dma.addr.addr_high =
+			cpu_to_le16((u16)upper_32_bits(pmc->descriptors[i].pa));
+		d->dma.status = 0; /* 0 = HW_OWNED */
+		d->dma.length = cpu_to_le16(descriptor_size);
+		d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
+		*_d = *d;
+	}
+
+	wil_dbg_misc(wil, "pmc_alloc: allocated successfully\n");
+
+	pmc_cmd.op = WMI_PMC_ALLOCATE;
+	pmc_cmd.ring_size = cpu_to_le16(pmc->num_descriptors);
+	pmc_cmd.mem_base = cpu_to_le64(pmc->pring_pa);
+
+	wil_dbg_misc(wil, "pmc_alloc: send WMI_PMC_CMD with ALLOCATE op\n");
+	pmc->last_cmd_status = wmi_send(wil,
+					WMI_PMC_CMDID,
+					vif->mid,
+					&pmc_cmd,
+					sizeof(pmc_cmd));
+	if (pmc->last_cmd_status) {
+		wil_err(wil,
+			"WMI_PMC_CMD with ALLOCATE op failed with status %d",
+			pmc->last_cmd_status);
+		goto release_pmc_skbs;
+	}
+
+	mutex_unlock(&pmc->lock);
+
+	return;
+
+release_pmc_skbs:
+	wil_err(wil, "exit on error: Releasing skbs...\n");
+	for (i = 0; i < num_descriptors && pmc->descriptors[i].va; i++) {
+		dma_free_coherent(dev,
+				  descriptor_size,
+				  pmc->descriptors[i].va,
+				  pmc->descriptors[i].pa);
+
+		pmc->descriptors[i].va = NULL;
+	}
+	wil_err(wil, "exit on error: Releasing pring...\n");
+
+	dma_free_coherent(dev,
+			  sizeof(struct vring_tx_desc) * num_descriptors,
+			  pmc->pring_va,
+			  pmc->pring_pa);
+
+	pmc->pring_va = NULL;
+
+release_pmc_skb_list:
+	wil_err(wil, "exit on error: Releasing descriptors info list...\n");
+	kfree(pmc->descriptors);
+	pmc->descriptors = NULL;
+
+no_release_err:
+	pmc->last_cmd_status = last_cmd_err;
+	mutex_unlock(&pmc->lock);
+}
+
+/* Traverse the p-ring and release all buffers.
+ * At the end release the p-ring memory
+ */
+void wil_pmc_free(struct wil6210_priv *wil, int send_pmc_cmd)
+{
+	struct pmc_ctx *pmc = &wil->pmc;
+	struct device *dev = wil_to_dev(wil);
+	struct wil6210_vif *vif = ndev_to_vif(wil->main_ndev);
+	struct wmi_pmc_cmd pmc_cmd = {0};
+
+	mutex_lock(&pmc->lock);
+
+	pmc->last_cmd_status = 0;
+
+	if (!wil_is_pmc_allocated(pmc)) {
+		wil_dbg_misc(wil,
+			     "pmc_free: Error, can't free - not allocated\n");
+		pmc->last_cmd_status = -EPERM;
+		mutex_unlock(&pmc->lock);
+		return;
+	}
+
+	if (send_pmc_cmd) {
+		wil_dbg_misc(wil, "send WMI_PMC_CMD with RELEASE op\n");
+		pmc_cmd.op = WMI_PMC_RELEASE;
+		pmc->last_cmd_status =
+				wmi_send(wil, WMI_PMC_CMDID, vif->mid,
+					 &pmc_cmd, sizeof(pmc_cmd));
+		if (pmc->last_cmd_status) {
+			wil_err(wil,
+				"WMI_PMC_CMD with RELEASE op failed, status %d",
+				pmc->last_cmd_status);
+			/* There's nothing we can do with this error.
+			 * Normally, it should never occur.
+			 * Continue to freeing all memory allocated for pmc.
+			 */
+		}
+	}
+
+	if (pmc->pring_va) {
+		size_t buf_size = sizeof(struct vring_tx_desc) *
+				  pmc->num_descriptors;
+
+		wil_dbg_misc(wil, "pmc_free: free pring va %p\n",
+			     pmc->pring_va);
+		dma_free_coherent(dev, buf_size, pmc->pring_va, pmc->pring_pa);
+
+		pmc->pring_va = NULL;
+	} else {
+		pmc->last_cmd_status = -ENOENT;
+	}
+
+	if (pmc->descriptors) {
+		int i;
+
+		for (i = 0;
+		     i < pmc->num_descriptors && pmc->descriptors[i].va; i++) {
+			dma_free_coherent(dev,
+					  pmc->descriptor_size,
+					  pmc->descriptors[i].va,
+					  pmc->descriptors[i].pa);
+			pmc->descriptors[i].va = NULL;
+		}
+		wil_dbg_misc(wil, "pmc_free: free descriptor info %d/%d\n", i,
+			     pmc->num_descriptors);
+		wil_dbg_misc(wil,
+			     "pmc_free: free pmc descriptors info list %p\n",
+			     pmc->descriptors);
+		kfree(pmc->descriptors);
+		pmc->descriptors = NULL;
+	} else {
+		pmc->last_cmd_status = -ENOENT;
+	}
+
+	mutex_unlock(&pmc->lock);
+}
+
+/* Status of the last operation requested via debugfs: alloc/free/read.
+ * 0 - success or negative errno
+ */
+int wil_pmc_last_cmd_status(struct wil6210_priv *wil)
+{
+	wil_dbg_misc(wil, "pmc_last_cmd_status: status %d\n",
+		     wil->pmc.last_cmd_status);
+
+	return wil->pmc.last_cmd_status;
+}
+
+/* Read from required position up to the end of current descriptor,
+ * depends on descriptor size configured during alloc request.
+ */
+ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count,
+		     loff_t *f_pos)
+{
+	struct wil6210_priv *wil = filp->private_data;
+	struct pmc_ctx *pmc = &wil->pmc;
+	size_t retval = 0;
+	unsigned long long idx;
+	loff_t offset;
+	size_t pmc_size;
+
+	mutex_lock(&pmc->lock);
+
+	if (!wil_is_pmc_allocated(pmc)) {
+		wil_err(wil, "error, pmc is not allocated!\n");
+		pmc->last_cmd_status = -EPERM;
+		mutex_unlock(&pmc->lock);
+		return -EPERM;
+	}
+
+	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
+
+	wil_dbg_misc(wil,
+		     "pmc_read: size %u, pos %lld\n",
+		     (u32)count, *f_pos);
+
+	pmc->last_cmd_status = 0;
+
+	idx = *f_pos;
+	do_div(idx, pmc->descriptor_size);
+	offset = *f_pos - (idx * pmc->descriptor_size);
+
+	if (*f_pos >= pmc_size) {
+		wil_dbg_misc(wil,
+			     "pmc_read: reached end of pmc buf: %lld >= %u\n",
+			     *f_pos, (u32)pmc_size);
+		pmc->last_cmd_status = -ERANGE;
+		goto out;
+	}
+
+	wil_dbg_misc(wil,
+		     "pmc_read: read from pos %lld (descriptor %llu, offset %llu) %zu bytes\n",
+		     *f_pos, idx, offset, count);
+
+	/* if no errors, return the copied byte count */
+	retval = simple_read_from_buffer(buf,
+					 count,
+					 &offset,
+					 pmc->descriptors[idx].va,
+					 pmc->descriptor_size);
+	*f_pos += retval;
+out:
+	mutex_unlock(&pmc->lock);
+
+	return retval;
+}
+
+loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence)
+{
+	loff_t newpos;
+	struct wil6210_priv *wil = filp->private_data;
+	struct pmc_ctx *pmc = &wil->pmc;
+	size_t pmc_size;
+
+	mutex_lock(&pmc->lock);
+
+	if (!wil_is_pmc_allocated(pmc)) {
+		wil_err(wil, "error, pmc is not allocated!\n");
+		pmc->last_cmd_status = -EPERM;
+		mutex_unlock(&pmc->lock);
+		return -EPERM;
+	}
+
+	pmc_size = pmc->descriptor_size * pmc->num_descriptors;
+
+	switch (whence) {
+	case 0: /* SEEK_SET */
+		newpos = off;
+		break;
+
+	case 1: /* SEEK_CUR */
+		newpos = filp->f_pos + off;
+		break;
+
+	case 2: /* SEEK_END */
+		newpos = pmc_size;
+		break;
+
+	default: /* can't happen */
+		newpos = -EINVAL;
+		goto out;
+	}
+
+	if (newpos < 0) {
+		newpos = -EINVAL;
+		goto out;
+	}
+	if (newpos > pmc_size)
+		newpos = pmc_size;
+
+	filp->f_pos = newpos;
+
+out:
+	mutex_unlock(&pmc->lock);
+
+	return newpos;
+}
+
+int wil_pmcring_read(struct seq_file *s, void *data)
+{
+	struct wil6210_priv *wil = s->private;
+	struct pmc_ctx *pmc = &wil->pmc;
+	size_t pmc_ring_size =
+		sizeof(struct vring_rx_desc) * pmc->num_descriptors;
+
+	mutex_lock(&pmc->lock);
+
+	if (!wil_is_pmc_allocated(pmc)) {
+		wil_err(wil, "error, pmc is not allocated!\n");
+		pmc->last_cmd_status = -EPERM;
+		mutex_unlock(&pmc->lock);
+		return -EPERM;
+	}
+
+	wil_dbg_misc(wil, "pmcring_read: size %zu\n", pmc_ring_size);
+
+	seq_write(s, pmc->pring_va, pmc_ring_size);
+
+	mutex_unlock(&pmc->lock);
+
+	return 0;
+}