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, 467 insertions, 0 deletions

diff --git a/drivers/media/pci/saa7164/saa7164-bus.c b/drivers/media/pci/saa7164/saa7164-bus.c
new file mode 100644
index 000000000..16739895a
--- /dev/null
+++ b/drivers/media/pci/saa7164/saa7164-bus.c
@@ -0,0 +1,467 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for the NXP SAA7164 PCIe bridge
+ *
+ *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
+ */
+
+#include "saa7164.h"
+
+/* The message bus to/from the firmware is a ring buffer in PCI address
+ * space. Establish the defaults.
+ */
+int saa7164_bus_setup(struct saa7164_dev *dev)
+{
+	struct tmComResBusInfo *b	= &dev->bus;
+
+	mutex_init(&b->lock);
+
+	b->Type			= TYPE_BUS_PCIe;
+	b->m_wMaxReqSize	= SAA_DEVICE_MAXREQUESTSIZE;
+
+	b->m_pdwSetRing		= (u8 __iomem *)(dev->bmmio +
+		((u32)dev->busdesc.CommandRing));
+
+	b->m_dwSizeSetRing	= SAA_DEVICE_BUFFERBLOCKSIZE;
+
+	b->m_pdwGetRing		= (u8 __iomem *)(dev->bmmio +
+		((u32)dev->busdesc.ResponseRing));
+
+	b->m_dwSizeGetRing	= SAA_DEVICE_BUFFERBLOCKSIZE;
+
+	b->m_dwSetWritePos	= ((u32)dev->intfdesc.BARLocation) +
+		(2 * sizeof(u64));
+	b->m_dwSetReadPos	= b->m_dwSetWritePos + (1 * sizeof(u32));
+
+	b->m_dwGetWritePos	= b->m_dwSetWritePos + (2 * sizeof(u32));
+	b->m_dwGetReadPos	= b->m_dwSetWritePos + (3 * sizeof(u32));
+
+	return 0;
+}
+
+void saa7164_bus_dump(struct saa7164_dev *dev)
+{
+	struct tmComResBusInfo *b = &dev->bus;
+
+	dprintk(DBGLVL_BUS, "Dumping the bus structure:\n");
+	dprintk(DBGLVL_BUS, " .type             = %d\n", b->Type);
+	dprintk(DBGLVL_BUS, " .dev->bmmio       = 0x%p\n", dev->bmmio);
+	dprintk(DBGLVL_BUS, " .m_wMaxReqSize    = 0x%x\n", b->m_wMaxReqSize);
+	dprintk(DBGLVL_BUS, " .m_pdwSetRing     = 0x%p\n", b->m_pdwSetRing);
+	dprintk(DBGLVL_BUS, " .m_dwSizeSetRing  = 0x%x\n", b->m_dwSizeSetRing);
+	dprintk(DBGLVL_BUS, " .m_pdwGetRing     = 0x%p\n", b->m_pdwGetRing);
+	dprintk(DBGLVL_BUS, " .m_dwSizeGetRing  = 0x%x\n", b->m_dwSizeGetRing);
+
+	dprintk(DBGLVL_BUS, " .m_dwSetReadPos   = 0x%x (0x%08x)\n",
+		b->m_dwSetReadPos, saa7164_readl(b->m_dwSetReadPos));
+
+	dprintk(DBGLVL_BUS, " .m_dwSetWritePos  = 0x%x (0x%08x)\n",
+		b->m_dwSetWritePos, saa7164_readl(b->m_dwSetWritePos));
+
+	dprintk(DBGLVL_BUS, " .m_dwGetReadPos   = 0x%x (0x%08x)\n",
+		b->m_dwGetReadPos, saa7164_readl(b->m_dwGetReadPos));
+
+	dprintk(DBGLVL_BUS, " .m_dwGetWritePos  = 0x%x (0x%08x)\n",
+		b->m_dwGetWritePos, saa7164_readl(b->m_dwGetWritePos));
+
+}
+
+/* Intensionally throw a BUG() if the state of the message bus looks corrupt */
+static void saa7164_bus_verify(struct saa7164_dev *dev)
+{
+	struct tmComResBusInfo *b = &dev->bus;
+	int bug = 0;
+
+	if (saa7164_readl(b->m_dwSetReadPos) > b->m_dwSizeSetRing)
+		bug++;
+
+	if (saa7164_readl(b->m_dwSetWritePos) > b->m_dwSizeSetRing)
+		bug++;
+
+	if (saa7164_readl(b->m_dwGetReadPos) > b->m_dwSizeGetRing)
+		bug++;
+
+	if (saa7164_readl(b->m_dwGetWritePos) > b->m_dwSizeGetRing)
+		bug++;
+
+	if (bug) {
+		saa_debug = 0xffff; /* Ensure we get the bus dump */
+		saa7164_bus_dump(dev);
+		saa_debug = 1024; /* Ensure we get the bus dump */
+		BUG();
+	}
+}
+
+static void saa7164_bus_dumpmsg(struct saa7164_dev *dev, struct tmComResInfo *m,
+				void *buf)
+{
+	dprintk(DBGLVL_BUS, "Dumping msg structure:\n");
+	dprintk(DBGLVL_BUS, " .id               = %d\n",   m->id);
+	dprintk(DBGLVL_BUS, " .flags            = 0x%x\n", m->flags);
+	dprintk(DBGLVL_BUS, " .size             = 0x%x\n", m->size);
+	dprintk(DBGLVL_BUS, " .command          = 0x%x\n", m->command);
+	dprintk(DBGLVL_BUS, " .controlselector  = 0x%x\n", m->controlselector);
+	dprintk(DBGLVL_BUS, " .seqno            = %d\n",   m->seqno);
+	if (buf)
+		dprintk(DBGLVL_BUS, " .buffer (ignored)\n");
+}
+
+/*
+ * Places a command or a response on the bus. The implementation does not
+ * know if it is a command or a response it just places the data on the
+ * bus depending on the bus information given in the struct tmComResBusInfo
+ * structure. If the command or response does not fit into the bus ring
+ * buffer it will be refused.
+ *
+ * Return Value:
+ *  SAA_OK     The function executed successfully.
+ *  < 0        One or more members are not initialized.
+ */
+int saa7164_bus_set(struct saa7164_dev *dev, struct tmComResInfo* msg,
+	void *buf)
+{
+	struct tmComResBusInfo *bus = &dev->bus;
+	u32 bytes_to_write, free_write_space, timeout, curr_srp, curr_swp;
+	u32 new_swp, space_rem;
+	int ret = SAA_ERR_BAD_PARAMETER;
+	u16 size;
+
+	if (!msg) {
+		printk(KERN_ERR "%s() !msg\n", __func__);
+		return SAA_ERR_BAD_PARAMETER;
+	}
+
+	dprintk(DBGLVL_BUS, "%s()\n", __func__);
+
+	saa7164_bus_verify(dev);
+
+	if (msg->size > dev->bus.m_wMaxReqSize) {
+		printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
+			__func__);
+		return SAA_ERR_BAD_PARAMETER;
+	}
+
+	if ((msg->size > 0) && (buf == NULL)) {
+		printk(KERN_ERR "%s() Missing message buffer\n", __func__);
+		return SAA_ERR_BAD_PARAMETER;
+	}
+
+	/* Lock the bus from any other access */
+	mutex_lock(&bus->lock);
+
+	bytes_to_write = sizeof(*msg) + msg->size;
+	free_write_space = 0;
+	timeout = SAA_BUS_TIMEOUT;
+	curr_srp = saa7164_readl(bus->m_dwSetReadPos);
+	curr_swp = saa7164_readl(bus->m_dwSetWritePos);
+
+	/* Deal with ring wrapping issues */
+	if (curr_srp > curr_swp)
+		/* Deal with the wrapped ring */
+		free_write_space = curr_srp - curr_swp;
+	else
+		/* The ring has not wrapped yet */
+		free_write_space = (curr_srp + bus->m_dwSizeSetRing) - curr_swp;
+
+	dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__,
+		bytes_to_write);
+
+	dprintk(DBGLVL_BUS, "%s() free_write_space = %d\n", __func__,
+		free_write_space);
+
+	dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp);
+	dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp);
+
+	/* Process the msg and write the content onto the bus */
+	while (bytes_to_write >= free_write_space) {
+
+		if (timeout-- == 0) {
+			printk(KERN_ERR "%s() bus timeout\n", __func__);
+			ret = SAA_ERR_NO_RESOURCES;
+			goto out;
+		}
+
+		/* TODO: Review this delay, efficient? */
+		/* Wait, allowing the hardware fetch time */
+		mdelay(1);
+
+		/* Check the space usage again */
+		curr_srp = saa7164_readl(bus->m_dwSetReadPos);
+
+		/* Deal with ring wrapping issues */
+		if (curr_srp > curr_swp)
+			/* Deal with the wrapped ring */
+			free_write_space = curr_srp - curr_swp;
+		else
+			/* Read didn't wrap around the buffer */
+			free_write_space = (curr_srp + bus->m_dwSizeSetRing) -
+				curr_swp;
+
+	}
+
+	/* Calculate the new write position */
+	new_swp = curr_swp + bytes_to_write;
+
+	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
+	dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__,
+		bus->m_dwSizeSetRing);
+
+	/*
+	 * Make a copy of msg->size before it is converted to le16 since it is
+	 * used in the code below.
+	 */
+	size = msg->size;
+	/* Convert to le16/le32 */
+	msg->size = (__force u16)cpu_to_le16(msg->size);
+	msg->command = (__force u32)cpu_to_le32(msg->command);
+	msg->controlselector = (__force u16)cpu_to_le16(msg->controlselector);
+
+	/* Mental Note: line 462 tmmhComResBusPCIe.cpp */
+
+	/* Check if we're going to wrap again */
+	if (new_swp > bus->m_dwSizeSetRing) {
+
+		/* Ring wraps */
+		new_swp -= bus->m_dwSizeSetRing;
+
+		space_rem = bus->m_dwSizeSetRing - curr_swp;
+
+		dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__,
+			space_rem);
+
+		dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__,
+			(u32)sizeof(*msg));
+
+		if (space_rem < sizeof(*msg)) {
+			dprintk(DBGLVL_BUS, "%s() tr4\n", __func__);
+
+			/* Split the msg into pieces as the ring wraps */
+			memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, space_rem);
+			memcpy_toio(bus->m_pdwSetRing, (u8 *)msg + space_rem,
+				sizeof(*msg) - space_rem);
+
+			memcpy_toio(bus->m_pdwSetRing + sizeof(*msg) - space_rem,
+				buf, size);
+
+		} else if (space_rem == sizeof(*msg)) {
+			dprintk(DBGLVL_BUS, "%s() tr5\n", __func__);
+
+			/* Additional data at the beginning of the ring */
+			memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
+			memcpy_toio(bus->m_pdwSetRing, buf, size);
+
+		} else {
+			/* Additional data wraps around the ring */
+			memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
+			if (size > 0) {
+				memcpy_toio(bus->m_pdwSetRing + curr_swp +
+					sizeof(*msg), buf, space_rem -
+					sizeof(*msg));
+				memcpy_toio(bus->m_pdwSetRing, (u8 *)buf +
+					space_rem - sizeof(*msg),
+					bytes_to_write - space_rem);
+			}
+
+		}
+
+	} /* (new_swp > bus->m_dwSizeSetRing) */
+	else {
+		dprintk(DBGLVL_BUS, "%s() tr6\n", __func__);
+
+		/* The ring buffer doesn't wrap, two simple copies */
+		memcpy_toio(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg));
+		memcpy_toio(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf,
+			size);
+	}
+
+	dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp);
+
+	/* Update the bus write position */
+	saa7164_writel(bus->m_dwSetWritePos, new_swp);
+
+	/* Convert back to cpu after writing the msg to the ringbuffer. */
+	msg->size = le16_to_cpu((__force __le16)msg->size);
+	msg->command = le32_to_cpu((__force __le32)msg->command);
+	msg->controlselector = le16_to_cpu((__force __le16)msg->controlselector);
+	ret = SAA_OK;
+
+out:
+	saa7164_bus_dump(dev);
+	mutex_unlock(&bus->lock);
+	saa7164_bus_verify(dev);
+	return ret;
+}
+
+/*
+ * Receive a command or a response from the bus. The implementation does not
+ * know if it is a command or a response it simply dequeues the data,
+ * depending on the bus information given in the struct tmComResBusInfo
+ * structure.
+ *
+ * Return Value:
+ *  0          The function executed successfully.
+ *  < 0        One or more members are not initialized.
+ */
+int saa7164_bus_get(struct saa7164_dev *dev, struct tmComResInfo* msg,
+	void *buf, int peekonly)
+{
+	struct tmComResBusInfo *bus = &dev->bus;
+	u32 bytes_to_read, write_distance, curr_grp, curr_gwp,
+		new_grp, buf_size, space_rem;
+	struct tmComResInfo msg_tmp;
+	int ret = SAA_ERR_BAD_PARAMETER;
+
+	saa7164_bus_verify(dev);
+
+	if (msg == NULL)
+		return ret;
+
+	if (msg->size > dev->bus.m_wMaxReqSize) {
+		printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n",
+			__func__);
+		return ret;
+	}
+
+	if ((peekonly == 0) && (msg->size > 0) && (buf == NULL)) {
+		printk(KERN_ERR
+			"%s() Missing msg buf, size should be %d bytes\n",
+			__func__, msg->size);
+		return ret;
+	}
+
+	mutex_lock(&bus->lock);
+
+	/* Peek the bus to see if a msg exists, if it's not what we're expecting
+	 * then return cleanly else read the message from the bus.
+	 */
+	curr_gwp = saa7164_readl(bus->m_dwGetWritePos);
+	curr_grp = saa7164_readl(bus->m_dwGetReadPos);
+
+	if (curr_gwp == curr_grp) {
+		ret = SAA_ERR_EMPTY;
+		goto out;
+	}
+
+	bytes_to_read = sizeof(*msg);
+
+	/* Calculate write distance to current read position */
+	write_distance = 0;
+	if (curr_gwp >= curr_grp)
+		/* Write doesn't wrap around the ring */
+		write_distance = curr_gwp - curr_grp;
+	else
+		/* Write wraps around the ring */
+		write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
+
+	if (bytes_to_read > write_distance) {
+		printk(KERN_ERR "%s() No message/response found\n", __func__);
+		ret = SAA_ERR_INVALID_COMMAND;
+		goto out;
+	}
+
+	/* Calculate the new read position */
+	new_grp = curr_grp + bytes_to_read;
+	if (new_grp > bus->m_dwSizeGetRing) {
+
+		/* Ring wraps */
+		new_grp -= bus->m_dwSizeGetRing;
+		space_rem = bus->m_dwSizeGetRing - curr_grp;
+
+		memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem);
+		memcpy_fromio((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing,
+			bytes_to_read - space_rem);
+
+	} else {
+		/* No wrapping */
+		memcpy_fromio(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read);
+	}
+	/* Convert from little endian to CPU */
+	msg_tmp.size = le16_to_cpu((__force __le16)msg_tmp.size);
+	msg_tmp.command = le32_to_cpu((__force __le32)msg_tmp.command);
+	msg_tmp.controlselector = le16_to_cpu((__force __le16)msg_tmp.controlselector);
+	memcpy(msg, &msg_tmp, sizeof(*msg));
+
+	/* No need to update the read positions, because this was a peek */
+	/* If the caller specifically want to peek, return */
+	if (peekonly) {
+		goto peekout;
+	}
+
+	/* Check if the command/response matches what is expected */
+	if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) ||
+		(msg_tmp.controlselector != msg->controlselector) ||
+		(msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) {
+
+		printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__);
+		saa7164_bus_dumpmsg(dev, msg, buf);
+		saa7164_bus_dumpmsg(dev, &msg_tmp, NULL);
+		ret = SAA_ERR_INVALID_COMMAND;
+		goto out;
+	}
+
+	/* Get the actual command and response from the bus */
+	buf_size = msg->size;
+
+	bytes_to_read = sizeof(*msg) + msg->size;
+	/* Calculate write distance to current read position */
+	write_distance = 0;
+	if (curr_gwp >= curr_grp)
+		/* Write doesn't wrap around the ring */
+		write_distance = curr_gwp - curr_grp;
+	else
+		/* Write wraps around the ring */
+		write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp;
+
+	if (bytes_to_read > write_distance) {
+		printk(KERN_ERR "%s() Invalid bus state, missing msg or mangled ring, faulty H/W / bad code?\n",
+		       __func__);
+		ret = SAA_ERR_INVALID_COMMAND;
+		goto out;
+	}
+
+	/* Calculate the new read position */
+	new_grp = curr_grp + bytes_to_read;
+	if (new_grp > bus->m_dwSizeGetRing) {
+
+		/* Ring wraps */
+		new_grp -= bus->m_dwSizeGetRing;
+		space_rem = bus->m_dwSizeGetRing - curr_grp;
+
+		if (space_rem < sizeof(*msg)) {
+			if (buf)
+				memcpy_fromio(buf, bus->m_pdwGetRing + sizeof(*msg) -
+					space_rem, buf_size);
+
+		} else if (space_rem == sizeof(*msg)) {
+			if (buf)
+				memcpy_fromio(buf, bus->m_pdwGetRing, buf_size);
+		} else {
+			/* Additional data wraps around the ring */
+			if (buf) {
+				memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp +
+					sizeof(*msg), space_rem - sizeof(*msg));
+				memcpy_fromio(buf + space_rem - sizeof(*msg),
+					bus->m_pdwGetRing, bytes_to_read -
+					space_rem);
+			}
+
+		}
+
+	} else {
+		/* No wrapping */
+		if (buf)
+			memcpy_fromio(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg),
+				buf_size);
+	}
+
+	/* Update the read positions, adjusting the ring */
+	saa7164_writel(bus->m_dwGetReadPos, new_grp);
+
+peekout:
+	ret = SAA_OK;
+out:
+	mutex_unlock(&bus->lock);
+	saa7164_bus_verify(dev);
+	return ret;
+}
+