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, 800 insertions, 0 deletions

diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
new file mode 100644
index 000000000..3ca2b5d9e
--- /dev/null
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -0,0 +1,800 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ */
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <soc/tegra/bpmp.h>
+#include <soc/tegra/bpmp-abi.h>
+
+static DEFINE_MUTEX(bpmp_debug_lock);
+
+struct seqbuf {
+	char *buf;
+	size_t pos;
+	size_t size;
+};
+
+static void seqbuf_init(struct seqbuf *seqbuf, void *buf, size_t size)
+{
+	seqbuf->buf = buf;
+	seqbuf->size = size;
+	seqbuf->pos = 0;
+}
+
+static size_t seqbuf_avail(struct seqbuf *seqbuf)
+{
+	return seqbuf->pos < seqbuf->size ? seqbuf->size - seqbuf->pos : 0;
+}
+
+static size_t seqbuf_status(struct seqbuf *seqbuf)
+{
+	return seqbuf->pos <= seqbuf->size ? 0 : -EOVERFLOW;
+}
+
+static int seqbuf_eof(struct seqbuf *seqbuf)
+{
+	return seqbuf->pos >= seqbuf->size;
+}
+
+static int seqbuf_read(struct seqbuf *seqbuf, void *buf, size_t nbyte)
+{
+	nbyte = min(nbyte, seqbuf_avail(seqbuf));
+	memcpy(buf, seqbuf->buf + seqbuf->pos, nbyte);
+	seqbuf->pos += nbyte;
+	return seqbuf_status(seqbuf);
+}
+
+static int seqbuf_read_u32(struct seqbuf *seqbuf, u32 *v)
+{
+	return seqbuf_read(seqbuf, v, 4);
+}
+
+static int seqbuf_read_str(struct seqbuf *seqbuf, const char **str)
+{
+	*str = seqbuf->buf + seqbuf->pos;
+	seqbuf->pos += strnlen(*str, seqbuf_avail(seqbuf));
+	seqbuf->pos++;
+	return seqbuf_status(seqbuf);
+}
+
+static void seqbuf_seek(struct seqbuf *seqbuf, ssize_t offset)
+{
+	seqbuf->pos += offset;
+}
+
+/* map filename in Linux debugfs to corresponding entry in BPMP */
+static const char *get_filename(struct tegra_bpmp *bpmp,
+				const struct file *file, char *buf, int size)
+{
+	const char *root_path, *filename = NULL;
+	char *root_path_buf;
+	size_t root_len;
+	size_t root_path_buf_len = 512;
+
+	root_path_buf = kzalloc(root_path_buf_len, GFP_KERNEL);
+	if (!root_path_buf)
+		goto out;
+
+	root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
+				root_path_buf_len);
+	if (IS_ERR(root_path))
+		goto out;
+
+	root_len = strlen(root_path);
+
+	filename = dentry_path(file->f_path.dentry, buf, size);
+	if (IS_ERR(filename)) {
+		filename = NULL;
+		goto out;
+	}
+
+	if (strlen(filename) < root_len || strncmp(filename, root_path, root_len)) {
+		filename = NULL;
+		goto out;
+	}
+
+	filename += root_len;
+
+out:
+	kfree(root_path_buf);
+	return filename;
+}
+
+static int mrq_debug_open(struct tegra_bpmp *bpmp, const char *name,
+			  u32 *fd, u32 *len, bool write)
+{
+	struct mrq_debug_request req = {
+		.cmd = write ? CMD_DEBUG_OPEN_WO : CMD_DEBUG_OPEN_RO,
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	ssize_t sz_name;
+	int err = 0;
+
+	sz_name = strscpy(req.fop.name, name, sizeof(req.fop.name));
+	if (sz_name < 0) {
+		pr_err("File name too large: %s\n", name);
+		return -EINVAL;
+	}
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	*len = resp.fop.datalen;
+	*fd = resp.fop.fd;
+
+	return 0;
+}
+
+static int mrq_debug_close(struct tegra_bpmp *bpmp, u32 fd)
+{
+	struct mrq_debug_request req = {
+		.cmd = CMD_DEBUG_CLOSE,
+		.frd = {
+			.fd = fd,
+		},
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	int err = 0;
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int mrq_debug_read(struct tegra_bpmp *bpmp, const char *name,
+			  char *data, size_t sz_data, u32 *nbytes)
+{
+	struct mrq_debug_request req = {
+		.cmd = CMD_DEBUG_READ,
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	u32 fd = 0, len = 0;
+	int remaining, err;
+
+	mutex_lock(&bpmp_debug_lock);
+	err = mrq_debug_open(bpmp, name, &fd, &len, 0);
+	if (err)
+		goto out;
+
+	if (len > sz_data) {
+		err = -EFBIG;
+		goto close;
+	}
+
+	req.frd.fd = fd;
+	remaining = len;
+
+	while (remaining > 0) {
+		err = tegra_bpmp_transfer(bpmp, &msg);
+		if (err < 0) {
+			goto close;
+		} else if (msg.rx.ret < 0) {
+			err = -EINVAL;
+			goto close;
+		}
+
+		if (resp.frd.readlen > remaining) {
+			pr_err("%s: read data length invalid\n", __func__);
+			err = -EINVAL;
+			goto close;
+		}
+
+		memcpy(data, resp.frd.data, resp.frd.readlen);
+		data += resp.frd.readlen;
+		remaining -= resp.frd.readlen;
+	}
+
+	*nbytes = len;
+
+close:
+	err = mrq_debug_close(bpmp, fd);
+out:
+	mutex_unlock(&bpmp_debug_lock);
+	return err;
+}
+
+static int mrq_debug_write(struct tegra_bpmp *bpmp, const char *name,
+			   uint8_t *data, size_t sz_data)
+{
+	struct mrq_debug_request req = {
+		.cmd = CMD_DEBUG_WRITE
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	u32 fd = 0, len = 0;
+	size_t remaining;
+	int err;
+
+	mutex_lock(&bpmp_debug_lock);
+	err = mrq_debug_open(bpmp, name, &fd, &len, 1);
+	if (err)
+		goto out;
+
+	if (sz_data > len) {
+		err = -EINVAL;
+		goto close;
+	}
+
+	req.fwr.fd = fd;
+	remaining = sz_data;
+
+	while (remaining > 0) {
+		len = min(remaining, sizeof(req.fwr.data));
+		memcpy(req.fwr.data, data, len);
+		req.fwr.datalen = len;
+
+		err = tegra_bpmp_transfer(bpmp, &msg);
+		if (err < 0) {
+			goto close;
+		} else if (msg.rx.ret < 0) {
+			err = -EINVAL;
+			goto close;
+		}
+
+		data += req.fwr.datalen;
+		remaining -= req.fwr.datalen;
+	}
+
+close:
+	err = mrq_debug_close(bpmp, fd);
+out:
+	mutex_unlock(&bpmp_debug_lock);
+	return err;
+}
+
+static int bpmp_debug_show(struct seq_file *m, void *p)
+{
+	struct file *file = m->private;
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	char fnamebuf[256];
+	const char *filename;
+	struct mrq_debug_request req = {
+		.cmd = CMD_DEBUG_READ,
+	};
+	struct mrq_debug_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUG,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	u32 fd = 0, len = 0;
+	int remaining, err;
+
+	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+	if (!filename)
+		return -ENOENT;
+
+	mutex_lock(&bpmp_debug_lock);
+	err = mrq_debug_open(bpmp, filename, &fd, &len, 0);
+	if (err)
+		goto out;
+
+	req.frd.fd = fd;
+	remaining = len;
+
+	while (remaining > 0) {
+		err = tegra_bpmp_transfer(bpmp, &msg);
+		if (err < 0) {
+			goto close;
+		} else if (msg.rx.ret < 0) {
+			err = -EINVAL;
+			goto close;
+		}
+
+		if (resp.frd.readlen > remaining) {
+			pr_err("%s: read data length invalid\n", __func__);
+			err = -EINVAL;
+			goto close;
+		}
+
+		seq_write(m, resp.frd.data, resp.frd.readlen);
+		remaining -= resp.frd.readlen;
+	}
+
+close:
+	err = mrq_debug_close(bpmp, fd);
+out:
+	mutex_unlock(&bpmp_debug_lock);
+	return err;
+}
+
+static ssize_t bpmp_debug_store(struct file *file, const char __user *buf,
+		size_t count, loff_t *f_pos)
+{
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	char *databuf = NULL;
+	char fnamebuf[256];
+	const char *filename;
+	ssize_t err;
+
+	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+	if (!filename)
+		return -ENOENT;
+
+	databuf = memdup_user(buf, count);
+	if (IS_ERR(databuf))
+		return PTR_ERR(databuf);
+
+	err = mrq_debug_write(bpmp, filename, databuf, count);
+	kfree(databuf);
+
+	return err ?: count;
+}
+
+static int bpmp_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open_size(file, bpmp_debug_show, file, SZ_256K);
+}
+
+static const struct file_operations bpmp_debug_fops = {
+	.open		= bpmp_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.write		= bpmp_debug_store,
+	.release	= single_release,
+};
+
+static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
+					struct dentry *parent,
+					char *ppath)
+{
+	const size_t pathlen = SZ_256;
+	const size_t bufsize = SZ_16K;
+	struct dentry *dentry;
+	u32 dsize, attrs = 0;
+	struct seqbuf seqbuf;
+	char *buf, *pathbuf;
+	const char *name;
+	int err = 0;
+
+	if (!bpmp || !parent || !ppath)
+		return -EINVAL;
+
+	buf = kmalloc(bufsize, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	pathbuf = kzalloc(pathlen, GFP_KERNEL);
+	if (!pathbuf) {
+		kfree(buf);
+		return -ENOMEM;
+	}
+
+	err = mrq_debug_read(bpmp, ppath, buf, bufsize, &dsize);
+	if (err)
+		goto out;
+
+	seqbuf_init(&seqbuf, buf, dsize);
+
+	while (!seqbuf_eof(&seqbuf)) {
+		err = seqbuf_read_u32(&seqbuf, &attrs);
+		if (err)
+			goto out;
+
+		err = seqbuf_read_str(&seqbuf, &name);
+		if (err < 0)
+			goto out;
+
+		if (attrs & DEBUGFS_S_ISDIR) {
+			size_t len;
+
+			dentry = debugfs_create_dir(name, parent);
+			if (IS_ERR(dentry)) {
+				err = PTR_ERR(dentry);
+				goto out;
+			}
+
+			len = snprintf(pathbuf, pathlen, "%s%s/", ppath, name);
+			if (len >= pathlen) {
+				err = -EINVAL;
+				goto out;
+			}
+
+			err = bpmp_populate_debugfs_inband(bpmp, dentry,
+							   pathbuf);
+			if (err < 0)
+				goto out;
+		} else {
+			umode_t mode;
+
+			mode = attrs & DEBUGFS_S_IRUSR ? 0400 : 0;
+			mode |= attrs & DEBUGFS_S_IWUSR ? 0200 : 0;
+			dentry = debugfs_create_file(name, mode, parent, bpmp,
+						     &bpmp_debug_fops);
+			if (IS_ERR(dentry)) {
+				err = -ENOMEM;
+				goto out;
+			}
+		}
+	}
+
+out:
+	kfree(pathbuf);
+	kfree(buf);
+
+	return err;
+}
+
+static int mrq_debugfs_read(struct tegra_bpmp *bpmp,
+			    dma_addr_t name, size_t sz_name,
+			    dma_addr_t data, size_t sz_data,
+			    size_t *nbytes)
+{
+	struct mrq_debugfs_request req = {
+		.cmd = CMD_DEBUGFS_READ,
+		.fop = {
+			.fnameaddr = (u32)name,
+			.fnamelen = (u32)sz_name,
+			.dataaddr = (u32)data,
+			.datalen = (u32)sz_data,
+		},
+	};
+	struct mrq_debugfs_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUGFS,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	int err;
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	*nbytes = (size_t)resp.fop.nbytes;
+
+	return 0;
+}
+
+static int mrq_debugfs_write(struct tegra_bpmp *bpmp,
+			     dma_addr_t name, size_t sz_name,
+			     dma_addr_t data, size_t sz_data)
+{
+	const struct mrq_debugfs_request req = {
+		.cmd = CMD_DEBUGFS_WRITE,
+		.fop = {
+			.fnameaddr = (u32)name,
+			.fnamelen = (u32)sz_name,
+			.dataaddr = (u32)data,
+			.datalen = (u32)sz_data,
+		},
+	};
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUGFS,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+	};
+
+	return tegra_bpmp_transfer(bpmp, &msg);
+}
+
+static int mrq_debugfs_dumpdir(struct tegra_bpmp *bpmp, dma_addr_t addr,
+			       size_t size, size_t *nbytes)
+{
+	const struct mrq_debugfs_request req = {
+		.cmd = CMD_DEBUGFS_DUMPDIR,
+		.dumpdir = {
+			.dataaddr = (u32)addr,
+			.datalen = (u32)size,
+		},
+	};
+	struct mrq_debugfs_response resp;
+	struct tegra_bpmp_message msg = {
+		.mrq = MRQ_DEBUGFS,
+		.tx = {
+			.data = &req,
+			.size = sizeof(req),
+		},
+		.rx = {
+			.data = &resp,
+			.size = sizeof(resp),
+		},
+	};
+	int err;
+
+	err = tegra_bpmp_transfer(bpmp, &msg);
+	if (err < 0)
+		return err;
+	else if (msg.rx.ret < 0)
+		return -EINVAL;
+
+	*nbytes = (size_t)resp.dumpdir.nbytes;
+
+	return 0;
+}
+
+static int debugfs_show(struct seq_file *m, void *p)
+{
+	struct file *file = m->private;
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	const size_t datasize = m->size;
+	const size_t namesize = SZ_256;
+	void *datavirt, *namevirt;
+	dma_addr_t dataphys, namephys;
+	char buf[256];
+	const char *filename;
+	size_t len, nbytes;
+	int err;
+
+	filename = get_filename(bpmp, file, buf, sizeof(buf));
+	if (!filename)
+		return -ENOENT;
+
+	namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
+				      GFP_KERNEL | GFP_DMA32);
+	if (!namevirt)
+		return -ENOMEM;
+
+	datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
+				      GFP_KERNEL | GFP_DMA32);
+	if (!datavirt) {
+		err = -ENOMEM;
+		goto free_namebuf;
+	}
+
+	len = strlen(filename);
+	strncpy(namevirt, filename, namesize);
+
+	err = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize,
+			       &nbytes);
+
+	if (!err)
+		seq_write(m, datavirt, nbytes);
+
+	dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
+free_namebuf:
+	dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
+
+	return err;
+}
+
+static int debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open_size(file, debugfs_show, file, SZ_128K);
+}
+
+static ssize_t debugfs_store(struct file *file, const char __user *buf,
+		size_t count, loff_t *f_pos)
+{
+	struct inode *inode = file_inode(file);
+	struct tegra_bpmp *bpmp = inode->i_private;
+	const size_t datasize = count;
+	const size_t namesize = SZ_256;
+	void *datavirt, *namevirt;
+	dma_addr_t dataphys, namephys;
+	char fnamebuf[256];
+	const char *filename;
+	size_t len;
+	int err;
+
+	filename = get_filename(bpmp, file, fnamebuf, sizeof(fnamebuf));
+	if (!filename)
+		return -ENOENT;
+
+	namevirt = dma_alloc_coherent(bpmp->dev, namesize, &namephys,
+				      GFP_KERNEL | GFP_DMA32);
+	if (!namevirt)
+		return -ENOMEM;
+
+	datavirt = dma_alloc_coherent(bpmp->dev, datasize, &dataphys,
+				      GFP_KERNEL | GFP_DMA32);
+	if (!datavirt) {
+		err = -ENOMEM;
+		goto free_namebuf;
+	}
+
+	len = strlen(filename);
+	strncpy(namevirt, filename, namesize);
+
+	if (copy_from_user(datavirt, buf, count)) {
+		err = -EFAULT;
+		goto free_databuf;
+	}
+
+	err = mrq_debugfs_write(bpmp, namephys, len, dataphys,
+				count);
+
+free_databuf:
+	dma_free_coherent(bpmp->dev, datasize, datavirt, dataphys);
+free_namebuf:
+	dma_free_coherent(bpmp->dev, namesize, namevirt, namephys);
+
+	return err ?: count;
+}
+
+static const struct file_operations debugfs_fops = {
+	.open		= debugfs_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.write		= debugfs_store,
+	.release	= single_release,
+};
+
+static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
+			     struct dentry *parent, u32 depth)
+{
+	int err;
+	u32 d, t;
+	const char *name;
+	struct dentry *dentry;
+
+	while (!seqbuf_eof(seqbuf)) {
+		err = seqbuf_read_u32(seqbuf, &d);
+		if (err < 0)
+			return err;
+
+		if (d < depth) {
+			seqbuf_seek(seqbuf, -4);
+			/* go up a level */
+			return 0;
+		} else if (d != depth) {
+			/* malformed data received from BPMP */
+			return -EIO;
+		}
+
+		err = seqbuf_read_u32(seqbuf, &t);
+		if (err < 0)
+			return err;
+		err = seqbuf_read_str(seqbuf, &name);
+		if (err < 0)
+			return err;
+
+		if (t & DEBUGFS_S_ISDIR) {
+			dentry = debugfs_create_dir(name, parent);
+			if (IS_ERR(dentry))
+				return -ENOMEM;
+			err = bpmp_populate_dir(bpmp, seqbuf, dentry, depth+1);
+			if (err < 0)
+				return err;
+		} else {
+			umode_t mode;
+
+			mode = t & DEBUGFS_S_IRUSR ? S_IRUSR : 0;
+			mode |= t & DEBUGFS_S_IWUSR ? S_IWUSR : 0;
+			dentry = debugfs_create_file(name, mode,
+						     parent, bpmp,
+						     &debugfs_fops);
+			if (IS_ERR(dentry))
+				return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp)
+{
+	struct seqbuf seqbuf;
+	const size_t sz = SZ_512K;
+	dma_addr_t phys;
+	size_t nbytes;
+	void *virt;
+	int err;
+
+	virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
+				  GFP_KERNEL | GFP_DMA32);
+	if (!virt)
+		return -ENOMEM;
+
+	err = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
+	if (err < 0) {
+		goto free;
+	} else if (nbytes > sz) {
+		err = -EINVAL;
+		goto free;
+	}
+
+	seqbuf_init(&seqbuf, virt, nbytes);
+	err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+free:
+	dma_free_coherent(bpmp->dev, sz, virt, phys);
+
+	return err;
+}
+
+int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
+{
+	struct dentry *root;
+	bool inband;
+	int err;
+
+	inband = tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUG);
+
+	if (!inband && !tegra_bpmp_mrq_is_supported(bpmp, MRQ_DEBUGFS))
+		return 0;
+
+	root = debugfs_create_dir("bpmp", NULL);
+	if (IS_ERR(root))
+		return -ENOMEM;
+
+	bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
+	if (IS_ERR(bpmp->debugfs_mirror)) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	if (inband)
+		err = bpmp_populate_debugfs_inband(bpmp, bpmp->debugfs_mirror,
+						   "/");
+	else
+		err = bpmp_populate_debugfs_shmem(bpmp);
+
+out:
+	if (err < 0)
+		debugfs_remove_recursive(root);
+
+	return err;
+}