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, 699 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/hif.c b/drivers/net/wireless/ath/ath6kl/hif.c
new file mode 100644
index 000000000..d1942537e
--- /dev/null
+++ b/drivers/net/wireless/ath/ath6kl/hif.c
@@ -0,0 +1,699 @@
+/*
+ * Copyright (c) 2007-2011 Atheros Communications Inc.
+ * Copyright (c) 2011-2012 Qualcomm Atheros, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include "hif.h"
+
+#include <linux/export.h>
+
+#include "core.h"
+#include "target.h"
+#include "hif-ops.h"
+#include "debug.h"
+#include "trace.h"
+
+#define MAILBOX_FOR_BLOCK_SIZE          1
+
+#define ATH6KL_TIME_QUANTUM	10  /* in ms */
+
+static int ath6kl_hif_cp_scat_dma_buf(struct hif_scatter_req *req,
+				      bool from_dma)
+{
+	u8 *buf;
+	int i;
+
+	buf = req->virt_dma_buf;
+
+	for (i = 0; i < req->scat_entries; i++) {
+		if (from_dma)
+			memcpy(req->scat_list[i].buf, buf,
+			       req->scat_list[i].len);
+		else
+			memcpy(buf, req->scat_list[i].buf,
+			       req->scat_list[i].len);
+
+		buf += req->scat_list[i].len;
+	}
+
+	return 0;
+}
+
+int ath6kl_hif_rw_comp_handler(void *context, int status)
+{
+	struct htc_packet *packet = context;
+
+	ath6kl_dbg(ATH6KL_DBG_HIF, "hif rw completion pkt 0x%p status %d\n",
+		   packet, status);
+
+	packet->status = status;
+	packet->completion(packet->context, packet);
+
+	return 0;
+}
+EXPORT_SYMBOL(ath6kl_hif_rw_comp_handler);
+
+#define REGISTER_DUMP_COUNT     60
+#define REGISTER_DUMP_LEN_MAX   60
+
+static void ath6kl_hif_dump_fw_crash(struct ath6kl *ar)
+{
+	__le32 regdump_val[REGISTER_DUMP_LEN_MAX];
+	u32 i, address, regdump_addr = 0;
+	int ret;
+
+	/* the reg dump pointer is copied to the host interest area */
+	address = ath6kl_get_hi_item_addr(ar, HI_ITEM(hi_failure_state));
+	address = TARG_VTOP(ar->target_type, address);
+
+	/* read RAM location through diagnostic window */
+	ret = ath6kl_diag_read32(ar, address, &regdump_addr);
+
+	if (ret || !regdump_addr) {
+		ath6kl_warn("failed to get ptr to register dump area: %d\n",
+			    ret);
+		return;
+	}
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ, "register dump data address 0x%x\n",
+		   regdump_addr);
+	regdump_addr = TARG_VTOP(ar->target_type, regdump_addr);
+
+	/* fetch register dump data */
+	ret = ath6kl_diag_read(ar, regdump_addr, (u8 *)&regdump_val[0],
+				  REGISTER_DUMP_COUNT * (sizeof(u32)));
+	if (ret) {
+		ath6kl_warn("failed to get register dump: %d\n", ret);
+		return;
+	}
+
+	ath6kl_info("crash dump:\n");
+	ath6kl_info("hw 0x%x fw %s\n", ar->wiphy->hw_version,
+		    ar->wiphy->fw_version);
+
+	BUILD_BUG_ON(REGISTER_DUMP_COUNT % 4);
+
+	for (i = 0; i < REGISTER_DUMP_COUNT; i += 4) {
+		ath6kl_info("%d: 0x%8.8x 0x%8.8x 0x%8.8x 0x%8.8x\n",
+			    i,
+			    le32_to_cpu(regdump_val[i]),
+			    le32_to_cpu(regdump_val[i + 1]),
+			    le32_to_cpu(regdump_val[i + 2]),
+			    le32_to_cpu(regdump_val[i + 3]));
+	}
+}
+
+static int ath6kl_hif_proc_dbg_intr(struct ath6kl_device *dev)
+{
+	u32 dummy;
+	int ret;
+
+	ath6kl_warn("firmware crashed\n");
+
+	/*
+	 * read counter to clear the interrupt, the debug error interrupt is
+	 * counter 0.
+	 */
+	ret = hif_read_write_sync(dev->ar, COUNT_DEC_ADDRESS,
+				     (u8 *)&dummy, 4, HIF_RD_SYNC_BYTE_INC);
+	if (ret)
+		ath6kl_warn("Failed to clear debug interrupt: %d\n", ret);
+
+	ath6kl_hif_dump_fw_crash(dev->ar);
+	ath6kl_read_fwlogs(dev->ar);
+	ath6kl_recovery_err_notify(dev->ar, ATH6KL_FW_ASSERT);
+
+	return ret;
+}
+
+/* mailbox recv message polling */
+int ath6kl_hif_poll_mboxmsg_rx(struct ath6kl_device *dev, u32 *lk_ahd,
+			      int timeout)
+{
+	struct ath6kl_irq_proc_registers *rg;
+	int status = 0, i;
+	u8 htc_mbox = 1 << HTC_MAILBOX;
+
+	for (i = timeout / ATH6KL_TIME_QUANTUM; i > 0; i--) {
+		/* this is the standard HIF way, load the reg table */
+		status = hif_read_write_sync(dev->ar, HOST_INT_STATUS_ADDRESS,
+					     (u8 *) &dev->irq_proc_reg,
+					     sizeof(dev->irq_proc_reg),
+					     HIF_RD_SYNC_BYTE_INC);
+
+		if (status) {
+			ath6kl_err("failed to read reg table\n");
+			return status;
+		}
+
+		/* check for MBOX data and valid lookahead */
+		if (dev->irq_proc_reg.host_int_status & htc_mbox) {
+			if (dev->irq_proc_reg.rx_lkahd_valid &
+			    htc_mbox) {
+				/*
+				 * Mailbox has a message and the look ahead
+				 * is valid.
+				 */
+				rg = &dev->irq_proc_reg;
+				*lk_ahd =
+					le32_to_cpu(rg->rx_lkahd[HTC_MAILBOX]);
+				break;
+			}
+		}
+
+		/* delay a little  */
+		mdelay(ATH6KL_TIME_QUANTUM);
+		ath6kl_dbg(ATH6KL_DBG_HIF, "hif retry mbox poll try %d\n", i);
+	}
+
+	if (i == 0) {
+		ath6kl_err("timeout waiting for recv message\n");
+		status = -ETIME;
+		/* check if the target asserted */
+		if (dev->irq_proc_reg.counter_int_status &
+		    ATH6KL_TARGET_DEBUG_INTR_MASK)
+			/*
+			 * Target failure handler will be called in case of
+			 * an assert.
+			 */
+			ath6kl_hif_proc_dbg_intr(dev);
+	}
+
+	return status;
+}
+
+/*
+ * Disable packet reception (used in case the host runs out of buffers)
+ * using the interrupt enable registers through the host I/F
+ */
+int ath6kl_hif_rx_control(struct ath6kl_device *dev, bool enable_rx)
+{
+	struct ath6kl_irq_enable_reg regs;
+	int status = 0;
+
+	ath6kl_dbg(ATH6KL_DBG_HIF, "hif rx %s\n",
+		   enable_rx ? "enable" : "disable");
+
+	/* take the lock to protect interrupt enable shadows */
+	spin_lock_bh(&dev->lock);
+
+	if (enable_rx)
+		dev->irq_en_reg.int_status_en |=
+			SM(INT_STATUS_ENABLE_MBOX_DATA, 0x01);
+	else
+		dev->irq_en_reg.int_status_en &=
+		    ~SM(INT_STATUS_ENABLE_MBOX_DATA, 0x01);
+
+	memcpy(&regs, &dev->irq_en_reg, sizeof(regs));
+
+	spin_unlock_bh(&dev->lock);
+
+	status = hif_read_write_sync(dev->ar, INT_STATUS_ENABLE_ADDRESS,
+				     &regs.int_status_en,
+				     sizeof(struct ath6kl_irq_enable_reg),
+				     HIF_WR_SYNC_BYTE_INC);
+
+	return status;
+}
+
+int ath6kl_hif_submit_scat_req(struct ath6kl_device *dev,
+			      struct hif_scatter_req *scat_req, bool read)
+{
+	int status = 0;
+
+	if (read) {
+		scat_req->req = HIF_RD_SYNC_BLOCK_FIX;
+		scat_req->addr = dev->ar->mbox_info.htc_addr;
+	} else {
+		scat_req->req = HIF_WR_ASYNC_BLOCK_INC;
+
+		scat_req->addr =
+			(scat_req->len > HIF_MBOX_WIDTH) ?
+			dev->ar->mbox_info.htc_ext_addr :
+			dev->ar->mbox_info.htc_addr;
+	}
+
+	ath6kl_dbg(ATH6KL_DBG_HIF,
+		   "hif submit scatter request entries %d len %d mbox 0x%x %s %s\n",
+		   scat_req->scat_entries, scat_req->len,
+		   scat_req->addr, !read ? "async" : "sync",
+		   (read) ? "rd" : "wr");
+
+	if (!read && scat_req->virt_scat) {
+		status = ath6kl_hif_cp_scat_dma_buf(scat_req, false);
+		if (status) {
+			scat_req->status = status;
+			scat_req->complete(dev->ar->htc_target, scat_req);
+			return 0;
+		}
+	}
+
+	status = ath6kl_hif_scat_req_rw(dev->ar, scat_req);
+
+	if (read) {
+		/* in sync mode, we can touch the scatter request */
+		scat_req->status = status;
+		if (!status && scat_req->virt_scat)
+			scat_req->status =
+				ath6kl_hif_cp_scat_dma_buf(scat_req, true);
+	}
+
+	return status;
+}
+
+static int ath6kl_hif_proc_counter_intr(struct ath6kl_device *dev)
+{
+	u8 counter_int_status;
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ, "counter interrupt\n");
+
+	counter_int_status = dev->irq_proc_reg.counter_int_status &
+			     dev->irq_en_reg.cntr_int_status_en;
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "valid interrupt source(s) in COUNTER_INT_STATUS: 0x%x\n",
+		counter_int_status);
+
+	/*
+	 * NOTE: other modules like GMBOX may use the counter interrupt for
+	 * credit flow control on other counters, we only need to check for
+	 * the debug assertion counter interrupt.
+	 */
+	if (counter_int_status & ATH6KL_TARGET_DEBUG_INTR_MASK)
+		return ath6kl_hif_proc_dbg_intr(dev);
+
+	return 0;
+}
+
+static int ath6kl_hif_proc_err_intr(struct ath6kl_device *dev)
+{
+	int status;
+	u8 error_int_status;
+	u8 reg_buf[4];
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ, "error interrupt\n");
+
+	error_int_status = dev->irq_proc_reg.error_int_status & 0x0F;
+	if (!error_int_status) {
+		WARN_ON(1);
+		return -EIO;
+	}
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "valid interrupt source(s) in ERROR_INT_STATUS: 0x%x\n",
+		   error_int_status);
+
+	if (MS(ERROR_INT_STATUS_WAKEUP, error_int_status))
+		ath6kl_dbg(ATH6KL_DBG_IRQ, "error : wakeup\n");
+
+	if (MS(ERROR_INT_STATUS_RX_UNDERFLOW, error_int_status))
+		ath6kl_err("rx underflow\n");
+
+	if (MS(ERROR_INT_STATUS_TX_OVERFLOW, error_int_status))
+		ath6kl_err("tx overflow\n");
+
+	/* Clear the interrupt */
+	dev->irq_proc_reg.error_int_status &= ~error_int_status;
+
+	/* set W1C value to clear the interrupt, this hits the register first */
+	reg_buf[0] = error_int_status;
+	reg_buf[1] = 0;
+	reg_buf[2] = 0;
+	reg_buf[3] = 0;
+
+	status = hif_read_write_sync(dev->ar, ERROR_INT_STATUS_ADDRESS,
+				     reg_buf, 4, HIF_WR_SYNC_BYTE_FIX);
+
+	WARN_ON(status);
+
+	return status;
+}
+
+static int ath6kl_hif_proc_cpu_intr(struct ath6kl_device *dev)
+{
+	int status;
+	u8 cpu_int_status;
+	u8 reg_buf[4];
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ, "cpu interrupt\n");
+
+	cpu_int_status = dev->irq_proc_reg.cpu_int_status &
+			 dev->irq_en_reg.cpu_int_status_en;
+	if (!cpu_int_status) {
+		WARN_ON(1);
+		return -EIO;
+	}
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "valid interrupt source(s) in CPU_INT_STATUS: 0x%x\n",
+		cpu_int_status);
+
+	/* Clear the interrupt */
+	dev->irq_proc_reg.cpu_int_status &= ~cpu_int_status;
+
+	/*
+	 * Set up the register transfer buffer to hit the register 4 times ,
+	 * this is done to make the access 4-byte aligned to mitigate issues
+	 * with host bus interconnects that restrict bus transfer lengths to
+	 * be a multiple of 4-bytes.
+	 */
+
+	/* set W1C value to clear the interrupt, this hits the register first */
+	reg_buf[0] = cpu_int_status;
+	/* the remaining are set to zero which have no-effect  */
+	reg_buf[1] = 0;
+	reg_buf[2] = 0;
+	reg_buf[3] = 0;
+
+	status = hif_read_write_sync(dev->ar, CPU_INT_STATUS_ADDRESS,
+				     reg_buf, 4, HIF_WR_SYNC_BYTE_FIX);
+
+	WARN_ON(status);
+
+	return status;
+}
+
+/* process pending interrupts synchronously */
+static int proc_pending_irqs(struct ath6kl_device *dev, bool *done)
+{
+	struct ath6kl_irq_proc_registers *rg;
+	int status = 0;
+	u8 host_int_status = 0;
+	u32 lk_ahd = 0;
+	u8 htc_mbox = 1 << HTC_MAILBOX;
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ, "proc_pending_irqs: (dev: 0x%p)\n", dev);
+
+	/*
+	 * NOTE: HIF implementation guarantees that the context of this
+	 * call allows us to perform SYNCHRONOUS I/O, that is we can block,
+	 * sleep or call any API that can block or switch thread/task
+	 * contexts. This is a fully schedulable context.
+	 */
+
+	/*
+	 * Process pending intr only when int_status_en is clear, it may
+	 * result in unnecessary bus transaction otherwise. Target may be
+	 * unresponsive at the time.
+	 */
+	if (dev->irq_en_reg.int_status_en) {
+		/*
+		 * Read the first 28 bytes of the HTC register table. This
+		 * will yield us the value of different int status
+		 * registers and the lookahead registers.
+		 *
+		 *    length = sizeof(int_status) + sizeof(cpu_int_status)
+		 *             + sizeof(error_int_status) +
+		 *             sizeof(counter_int_status) +
+		 *             sizeof(mbox_frame) + sizeof(rx_lkahd_valid)
+		 *             + sizeof(hole) + sizeof(rx_lkahd) +
+		 *             sizeof(int_status_en) +
+		 *             sizeof(cpu_int_status_en) +
+		 *             sizeof(err_int_status_en) +
+		 *             sizeof(cntr_int_status_en);
+		 */
+		status = hif_read_write_sync(dev->ar, HOST_INT_STATUS_ADDRESS,
+					     (u8 *) &dev->irq_proc_reg,
+					     sizeof(dev->irq_proc_reg),
+					     HIF_RD_SYNC_BYTE_INC);
+		if (status)
+			goto out;
+
+		ath6kl_dump_registers(dev, &dev->irq_proc_reg,
+				      &dev->irq_en_reg);
+		trace_ath6kl_sdio_irq(&dev->irq_en_reg,
+				      sizeof(dev->irq_en_reg));
+
+		/* Update only those registers that are enabled */
+		host_int_status = dev->irq_proc_reg.host_int_status &
+				  dev->irq_en_reg.int_status_en;
+
+		/* Look at mbox status */
+		if (host_int_status & htc_mbox) {
+			/*
+			 * Mask out pending mbox value, we use "lookAhead as
+			 * the real flag for mbox processing.
+			 */
+			host_int_status &= ~htc_mbox;
+			if (dev->irq_proc_reg.rx_lkahd_valid &
+			    htc_mbox) {
+				rg = &dev->irq_proc_reg;
+				lk_ahd = le32_to_cpu(rg->rx_lkahd[HTC_MAILBOX]);
+				if (!lk_ahd)
+					ath6kl_err("lookAhead is zero!\n");
+			}
+		}
+	}
+
+	if (!host_int_status && !lk_ahd) {
+		*done = true;
+		goto out;
+	}
+
+	if (lk_ahd) {
+		int fetched = 0;
+
+		ath6kl_dbg(ATH6KL_DBG_IRQ,
+			   "pending mailbox msg, lk_ahd: 0x%X\n", lk_ahd);
+		/*
+		 * Mailbox Interrupt, the HTC layer may issue async
+		 * requests to empty the mailbox. When emptying the recv
+		 * mailbox we use the async handler above called from the
+		 * completion routine of the callers read request. This can
+		 * improve performance by reducing context switching when
+		 * we rapidly pull packets.
+		 */
+		status = ath6kl_htc_rxmsg_pending_handler(dev->htc_cnxt,
+							  lk_ahd, &fetched);
+		if (status)
+			goto out;
+
+		if (!fetched)
+			/*
+			 * HTC could not pull any messages out due to lack
+			 * of resources.
+			 */
+			dev->htc_cnxt->chk_irq_status_cnt = 0;
+	}
+
+	/* now handle the rest of them */
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "valid interrupt source(s) for other interrupts: 0x%x\n",
+		   host_int_status);
+
+	if (MS(HOST_INT_STATUS_CPU, host_int_status)) {
+		/* CPU Interrupt */
+		status = ath6kl_hif_proc_cpu_intr(dev);
+		if (status)
+			goto out;
+	}
+
+	if (MS(HOST_INT_STATUS_ERROR, host_int_status)) {
+		/* Error Interrupt */
+		status = ath6kl_hif_proc_err_intr(dev);
+		if (status)
+			goto out;
+	}
+
+	if (MS(HOST_INT_STATUS_COUNTER, host_int_status))
+		/* Counter Interrupt */
+		status = ath6kl_hif_proc_counter_intr(dev);
+
+out:
+	/*
+	 * An optimization to bypass reading the IRQ status registers
+	 * unecessarily which can re-wake the target, if upper layers
+	 * determine that we are in a low-throughput mode, we can rely on
+	 * taking another interrupt rather than re-checking the status
+	 * registers which can re-wake the target.
+	 *
+	 * NOTE : for host interfaces that makes use of detecting pending
+	 * mbox messages at hif can not use this optimization due to
+	 * possible side effects, SPI requires the host to drain all
+	 * messages from the mailbox before exiting the ISR routine.
+	 */
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "bypassing irq status re-check, forcing done\n");
+
+	if (!dev->htc_cnxt->chk_irq_status_cnt)
+		*done = true;
+
+	ath6kl_dbg(ATH6KL_DBG_IRQ,
+		   "proc_pending_irqs: (done:%d, status=%d\n", *done, status);
+
+	return status;
+}
+
+/* interrupt handler, kicks off all interrupt processing */
+int ath6kl_hif_intr_bh_handler(struct ath6kl *ar)
+{
+	struct ath6kl_device *dev = ar->htc_target->dev;
+	unsigned long timeout;
+	int status = 0;
+	bool done = false;
+
+	/*
+	 * Reset counter used to flag a re-scan of IRQ status registers on
+	 * the target.
+	 */
+	dev->htc_cnxt->chk_irq_status_cnt = 0;
+
+	/*
+	 * IRQ processing is synchronous, interrupt status registers can be
+	 * re-read.
+	 */
+	timeout = jiffies + msecs_to_jiffies(ATH6KL_HIF_COMMUNICATION_TIMEOUT);
+	while (time_before(jiffies, timeout) && !done) {
+		status = proc_pending_irqs(dev, &done);
+		if (status)
+			break;
+	}
+
+	return status;
+}
+EXPORT_SYMBOL(ath6kl_hif_intr_bh_handler);
+
+static int ath6kl_hif_enable_intrs(struct ath6kl_device *dev)
+{
+	struct ath6kl_irq_enable_reg regs;
+	int status;
+
+	spin_lock_bh(&dev->lock);
+
+	/* Enable all but ATH6KL CPU interrupts */
+	dev->irq_en_reg.int_status_en =
+			SM(INT_STATUS_ENABLE_ERROR, 0x01) |
+			SM(INT_STATUS_ENABLE_CPU, 0x01) |
+			SM(INT_STATUS_ENABLE_COUNTER, 0x01);
+
+	/*
+	 * NOTE: There are some cases where HIF can do detection of
+	 * pending mbox messages which is disabled now.
+	 */
+	dev->irq_en_reg.int_status_en |= SM(INT_STATUS_ENABLE_MBOX_DATA, 0x01);
+
+	/* Set up the CPU Interrupt status Register */
+	dev->irq_en_reg.cpu_int_status_en = 0;
+
+	/* Set up the Error Interrupt status Register */
+	dev->irq_en_reg.err_int_status_en =
+		SM(ERROR_STATUS_ENABLE_RX_UNDERFLOW, 0x01) |
+		SM(ERROR_STATUS_ENABLE_TX_OVERFLOW, 0x1);
+
+	/*
+	 * Enable Counter interrupt status register to get fatal errors for
+	 * debugging.
+	 */
+	dev->irq_en_reg.cntr_int_status_en = SM(COUNTER_INT_STATUS_ENABLE_BIT,
+						ATH6KL_TARGET_DEBUG_INTR_MASK);
+	memcpy(&regs, &dev->irq_en_reg, sizeof(regs));
+
+	spin_unlock_bh(&dev->lock);
+
+	status = hif_read_write_sync(dev->ar, INT_STATUS_ENABLE_ADDRESS,
+				     &regs.int_status_en, sizeof(regs),
+				     HIF_WR_SYNC_BYTE_INC);
+
+	if (status)
+		ath6kl_err("failed to update interrupt ctl reg err: %d\n",
+			   status);
+
+	return status;
+}
+
+int ath6kl_hif_disable_intrs(struct ath6kl_device *dev)
+{
+	struct ath6kl_irq_enable_reg regs;
+
+	spin_lock_bh(&dev->lock);
+	/* Disable all interrupts */
+	dev->irq_en_reg.int_status_en = 0;
+	dev->irq_en_reg.cpu_int_status_en = 0;
+	dev->irq_en_reg.err_int_status_en = 0;
+	dev->irq_en_reg.cntr_int_status_en = 0;
+	memcpy(&regs, &dev->irq_en_reg, sizeof(regs));
+	spin_unlock_bh(&dev->lock);
+
+	return hif_read_write_sync(dev->ar, INT_STATUS_ENABLE_ADDRESS,
+				   &regs.int_status_en, sizeof(regs),
+				   HIF_WR_SYNC_BYTE_INC);
+}
+
+/* enable device interrupts */
+int ath6kl_hif_unmask_intrs(struct ath6kl_device *dev)
+{
+	int status = 0;
+
+	/*
+	 * Make sure interrupt are disabled before unmasking at the HIF
+	 * layer. The rationale here is that between device insertion
+	 * (where we clear the interrupts the first time) and when HTC
+	 * is finally ready to handle interrupts, other software can perform
+	 * target "soft" resets. The ATH6KL interrupt enables reset back to an
+	 * "enabled" state when this happens.
+	 */
+	ath6kl_hif_disable_intrs(dev);
+
+	/* unmask the host controller interrupts */
+	ath6kl_hif_irq_enable(dev->ar);
+	status = ath6kl_hif_enable_intrs(dev);
+
+	return status;
+}
+
+/* disable all device interrupts */
+int ath6kl_hif_mask_intrs(struct ath6kl_device *dev)
+{
+	/*
+	 * Mask the interrupt at the HIF layer to avoid any stray interrupt
+	 * taken while we zero out our shadow registers in
+	 * ath6kl_hif_disable_intrs().
+	 */
+	ath6kl_hif_irq_disable(dev->ar);
+
+	return ath6kl_hif_disable_intrs(dev);
+}
+
+int ath6kl_hif_setup(struct ath6kl_device *dev)
+{
+	int status = 0;
+
+	spin_lock_init(&dev->lock);
+
+	/*
+	 * NOTE: we actually get the block size of a mailbox other than 0,
+	 * for SDIO the block size on mailbox 0 is artificially set to 1.
+	 * So we use the block size that is set for the other 3 mailboxes.
+	 */
+	dev->htc_cnxt->block_sz = dev->ar->mbox_info.block_size;
+
+	/* must be a power of 2 */
+	if ((dev->htc_cnxt->block_sz & (dev->htc_cnxt->block_sz - 1)) != 0) {
+		WARN_ON(1);
+		status = -EINVAL;
+		goto fail_setup;
+	}
+
+	/* assemble mask, used for padding to a block */
+	dev->htc_cnxt->block_mask = dev->htc_cnxt->block_sz - 1;
+
+	ath6kl_dbg(ATH6KL_DBG_HIF, "hif block size %d mbox addr 0x%x\n",
+		   dev->htc_cnxt->block_sz, dev->ar->mbox_info.htc_addr);
+
+	status = ath6kl_hif_disable_intrs(dev);
+
+fail_setup:
+	return status;
+}