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, 594 insertions, 0 deletions

diff --git a/crypto/async_tx/async_raid6_recov.c b/crypto/async_tx/async_raid6_recov.c
new file mode 100644
index 000000000..354b8cd55
--- /dev/null
+++ b/crypto/async_tx/async_raid6_recov.c
@@ -0,0 +1,594 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Asynchronous RAID-6 recovery calculations ASYNC_TX API.
+ * Copyright(c) 2009 Intel Corporation
+ *
+ * based on raid6recov.c:
+ *   Copyright 2002 H. Peter Anvin
+ */
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/raid/pq.h>
+#include <linux/async_tx.h>
+#include <linux/dmaengine.h>
+
+static struct dma_async_tx_descriptor *
+async_sum_product(struct page *dest, unsigned int d_off,
+		struct page **srcs, unsigned int *src_offs, unsigned char *coef,
+		size_t len, struct async_submit_ctl *submit)
+{
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
+						      &dest, 1, srcs, 2, len);
+	struct dma_device *dma = chan ? chan->device : NULL;
+	struct dmaengine_unmap_data *unmap = NULL;
+	const u8 *amul, *bmul;
+	u8 ax, bx;
+	u8 *a, *b, *c;
+
+	if (dma)
+		unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT);
+
+	if (unmap) {
+		struct device *dev = dma->dev;
+		dma_addr_t pq[2];
+		struct dma_async_tx_descriptor *tx;
+		enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
+
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+		unmap->addr[0] = dma_map_page(dev, srcs[0], src_offs[0],
+						len, DMA_TO_DEVICE);
+		unmap->addr[1] = dma_map_page(dev, srcs[1], src_offs[1],
+						len, DMA_TO_DEVICE);
+		unmap->to_cnt = 2;
+
+		unmap->addr[2] = dma_map_page(dev, dest, d_off,
+						len, DMA_BIDIRECTIONAL);
+		unmap->bidi_cnt = 1;
+		/* engine only looks at Q, but expects it to follow P */
+		pq[1] = unmap->addr[2];
+
+		unmap->len = len;
+		tx = dma->device_prep_dma_pq(chan, pq, unmap->addr, 2, coef,
+					     len, dma_flags);
+		if (tx) {
+			dma_set_unmap(tx, unmap);
+			async_tx_submit(chan, tx, submit);
+			dmaengine_unmap_put(unmap);
+			return tx;
+		}
+
+		/* could not get a descriptor, unmap and fall through to
+		 * the synchronous path
+		 */
+		dmaengine_unmap_put(unmap);
+	}
+
+	/* run the operation synchronously */
+	async_tx_quiesce(&submit->depend_tx);
+	amul = raid6_gfmul[coef[0]];
+	bmul = raid6_gfmul[coef[1]];
+	a = page_address(srcs[0]) + src_offs[0];
+	b = page_address(srcs[1]) + src_offs[1];
+	c = page_address(dest) + d_off;
+
+	while (len--) {
+		ax    = amul[*a++];
+		bx    = bmul[*b++];
+		*c++ = ax ^ bx;
+	}
+
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+async_mult(struct page *dest, unsigned int d_off, struct page *src,
+		unsigned int s_off, u8 coef, size_t len,
+		struct async_submit_ctl *submit)
+{
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
+						      &dest, 1, &src, 1, len);
+	struct dma_device *dma = chan ? chan->device : NULL;
+	struct dmaengine_unmap_data *unmap = NULL;
+	const u8 *qmul; /* Q multiplier table */
+	u8 *d, *s;
+
+	if (dma)
+		unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT);
+
+	if (unmap) {
+		dma_addr_t dma_dest[2];
+		struct device *dev = dma->dev;
+		struct dma_async_tx_descriptor *tx;
+		enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
+
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+		unmap->addr[0] = dma_map_page(dev, src, s_off,
+						len, DMA_TO_DEVICE);
+		unmap->to_cnt++;
+		unmap->addr[1] = dma_map_page(dev, dest, d_off,
+						len, DMA_BIDIRECTIONAL);
+		dma_dest[1] = unmap->addr[1];
+		unmap->bidi_cnt++;
+		unmap->len = len;
+
+		/* this looks funny, but the engine looks for Q at
+		 * dma_dest[1] and ignores dma_dest[0] as a dest
+		 * due to DMA_PREP_PQ_DISABLE_P
+		 */
+		tx = dma->device_prep_dma_pq(chan, dma_dest, unmap->addr,
+					     1, &coef, len, dma_flags);
+
+		if (tx) {
+			dma_set_unmap(tx, unmap);
+			dmaengine_unmap_put(unmap);
+			async_tx_submit(chan, tx, submit);
+			return tx;
+		}
+
+		/* could not get a descriptor, unmap and fall through to
+		 * the synchronous path
+		 */
+		dmaengine_unmap_put(unmap);
+	}
+
+	/* no channel available, or failed to allocate a descriptor, so
+	 * perform the operation synchronously
+	 */
+	async_tx_quiesce(&submit->depend_tx);
+	qmul  = raid6_gfmul[coef];
+	d = page_address(dest) + d_off;
+	s = page_address(src) + s_off;
+
+	while (len--)
+		*d++ = qmul[*s++];
+
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_4(int disks, size_t bytes, int faila, int failb,
+		struct page **blocks, unsigned int *offs,
+		struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *a, *b;
+	unsigned int p_off, q_off, a_off, b_off;
+	struct page *srcs[2];
+	unsigned int src_offs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+
+	p = blocks[disks-2];
+	p_off = offs[disks-2];
+	q = blocks[disks-1];
+	q_off = offs[disks-1];
+
+	a = blocks[faila];
+	a_off = offs[faila];
+	b = blocks[failb];
+	b_off = offs[failb];
+
+	/* in the 4 disk case P + Pxy == P and Q + Qxy == Q */
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = p;
+	src_offs[0] = p_off;
+	srcs[1] = q;
+	src_offs[1] = q_off;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(b, b_off, srcs, src_offs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = p;
+	src_offs[0] = p_off;
+	srcs[1] = b;
+	src_offs[1] = b_off;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_ZERO_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor_offs(a, a_off, srcs, src_offs, 2, bytes, submit);
+
+	return tx;
+
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_5(int disks, size_t bytes, int faila, int failb,
+		struct page **blocks, unsigned int *offs,
+		struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *g, *dp, *dq;
+	unsigned int p_off, q_off, g_off, dp_off, dq_off;
+	struct page *srcs[2];
+	unsigned int src_offs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+	int good_srcs, good, i;
+
+	good_srcs = 0;
+	good = -1;
+	for (i = 0; i < disks-2; i++) {
+		if (blocks[i] == NULL)
+			continue;
+		if (i == faila || i == failb)
+			continue;
+		good = i;
+		good_srcs++;
+	}
+	BUG_ON(good_srcs > 1);
+
+	p = blocks[disks-2];
+	p_off = offs[disks-2];
+	q = blocks[disks-1];
+	q_off = offs[disks-1];
+	g = blocks[good];
+	g_off = offs[good];
+
+	/* Compute syndrome with zero for the missing data pages
+	 * Use the dead data pages as temporary storage for delta p and
+	 * delta q
+	 */
+	dp = blocks[faila];
+	dp_off = offs[faila];
+	dq = blocks[failb];
+	dq_off = offs[failb];
+
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_memcpy(dp, g, dp_off, g_off, bytes, submit);
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_mult(dq, dq_off, g, g_off,
+			raid6_gfexp[good], bytes, submit);
+
+	/* compute P + Pxy */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = p;
+	src_offs[1] = p_off;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
+
+	/* compute Q + Qxy */
+	srcs[0] = dq;
+	src_offs[0] = dq_off;
+	srcs[1] = q;
+	src_offs[1] = q_off;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
+
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = dq;
+	src_offs[1] = dq_off;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(dq, dq_off, srcs, src_offs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = dq;
+	src_offs[1] = dq_off;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
+
+	return tx;
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_n(int disks, size_t bytes, int faila, int failb,
+	      struct page **blocks, unsigned int *offs,
+		  struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *dp, *dq;
+	unsigned int p_off, q_off, dp_off, dq_off;
+	struct page *srcs[2];
+	unsigned int src_offs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+
+	p = blocks[disks-2];
+	p_off = offs[disks-2];
+	q = blocks[disks-1];
+	q_off = offs[disks-1];
+
+	/* Compute syndrome with zero for the missing data pages
+	 * Use the dead data pages as temporary storage for
+	 * delta p and delta q
+	 */
+	dp = blocks[faila];
+	dp_off = offs[faila];
+	blocks[faila] = NULL;
+	blocks[disks-2] = dp;
+	offs[disks-2] = dp_off;
+	dq = blocks[failb];
+	dq_off = offs[failb];
+	blocks[failb] = NULL;
+	blocks[disks-1] = dq;
+	offs[disks-1] = dq_off;
+
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_gen_syndrome(blocks, offs, disks, bytes, submit);
+
+	/* Restore pointer table */
+	blocks[faila]   = dp;
+	offs[faila] = dp_off;
+	blocks[failb]   = dq;
+	offs[failb] = dq_off;
+	blocks[disks-2] = p;
+	offs[disks-2] = p_off;
+	blocks[disks-1] = q;
+	offs[disks-1] = q_off;
+
+	/* compute P + Pxy */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = p;
+	src_offs[1] = p_off;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
+
+	/* compute Q + Qxy */
+	srcs[0] = dq;
+	src_offs[0] = dq_off;
+	srcs[1] = q;
+	src_offs[1] = q_off;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
+
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = dq;
+	src_offs[1] = dq_off;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(dq, dq_off, srcs, src_offs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = dp;
+	src_offs[0] = dp_off;
+	srcs[1] = dq;
+	src_offs[1] = dq_off;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor_offs(dp, dp_off, srcs, src_offs, 2, bytes, submit);
+
+	return tx;
+}
+
+/**
+ * async_raid6_2data_recov - asynchronously calculate two missing data blocks
+ * @disks: number of disks in the RAID-6 array
+ * @bytes: block size
+ * @faila: first failed drive index
+ * @failb: second failed drive index
+ * @blocks: array of source pointers where the last two entries are p and q
+ * @offs: array of offset for pages in blocks
+ * @submit: submission/completion modifiers
+ */
+struct dma_async_tx_descriptor *
+async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
+			struct page **blocks, unsigned int *offs,
+			struct async_submit_ctl *submit)
+{
+	void *scribble = submit->scribble;
+	int non_zero_srcs, i;
+
+	BUG_ON(faila == failb);
+	if (failb < faila)
+		swap(faila, failb);
+
+	pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
+
+	/* if a dma resource is not available or a scribble buffer is not
+	 * available punt to the synchronous path.  In the 'dma not
+	 * available' case be sure to use the scribble buffer to
+	 * preserve the content of 'blocks' as the caller intended.
+	 */
+	if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+		void **ptrs = scribble ? scribble : (void **) blocks;
+
+		async_tx_quiesce(&submit->depend_tx);
+		for (i = 0; i < disks; i++)
+			if (blocks[i] == NULL)
+				ptrs[i] = (void *) raid6_empty_zero_page;
+			else
+				ptrs[i] = page_address(blocks[i]) + offs[i];
+
+		raid6_2data_recov(disks, bytes, faila, failb, ptrs);
+
+		async_tx_sync_epilog(submit);
+
+		return NULL;
+	}
+
+	non_zero_srcs = 0;
+	for (i = 0; i < disks-2 && non_zero_srcs < 4; i++)
+		if (blocks[i])
+			non_zero_srcs++;
+	switch (non_zero_srcs) {
+	case 0:
+	case 1:
+		/* There must be at least 2 sources - the failed devices. */
+		BUG();
+
+	case 2:
+		/* dma devices do not uniformly understand a zero source pq
+		 * operation (in contrast to the synchronous case), so
+		 * explicitly handle the special case of a 4 disk array with
+		 * both data disks missing.
+		 */
+		return __2data_recov_4(disks, bytes, faila, failb,
+				blocks, offs, submit);
+	case 3:
+		/* dma devices do not uniformly understand a single
+		 * source pq operation (in contrast to the synchronous
+		 * case), so explicitly handle the special case of a 5 disk
+		 * array with 2 of 3 data disks missing.
+		 */
+		return __2data_recov_5(disks, bytes, faila, failb,
+				blocks, offs, submit);
+	default:
+		return __2data_recov_n(disks, bytes, faila, failb,
+				blocks, offs, submit);
+	}
+}
+EXPORT_SYMBOL_GPL(async_raid6_2data_recov);
+
+/**
+ * async_raid6_datap_recov - asynchronously calculate a data and the 'p' block
+ * @disks: number of disks in the RAID-6 array
+ * @bytes: block size
+ * @faila: failed drive index
+ * @blocks: array of source pointers where the last two entries are p and q
+ * @offs: array of offset for pages in blocks
+ * @submit: submission/completion modifiers
+ */
+struct dma_async_tx_descriptor *
+async_raid6_datap_recov(int disks, size_t bytes, int faila,
+			struct page **blocks, unsigned int *offs,
+			struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *dq;
+	unsigned int p_off, q_off, dq_off;
+	u8 coef;
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+	int good_srcs, good, i;
+	struct page *srcs[2];
+	unsigned int src_offs[2];
+
+	pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
+
+	/* if a dma resource is not available or a scribble buffer is not
+	 * available punt to the synchronous path.  In the 'dma not
+	 * available' case be sure to use the scribble buffer to
+	 * preserve the content of 'blocks' as the caller intended.
+	 */
+	if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+		void **ptrs = scribble ? scribble : (void **) blocks;
+
+		async_tx_quiesce(&submit->depend_tx);
+		for (i = 0; i < disks; i++)
+			if (blocks[i] == NULL)
+				ptrs[i] = (void*)raid6_empty_zero_page;
+			else
+				ptrs[i] = page_address(blocks[i]) + offs[i];
+
+		raid6_datap_recov(disks, bytes, faila, ptrs);
+
+		async_tx_sync_epilog(submit);
+
+		return NULL;
+	}
+
+	good_srcs = 0;
+	good = -1;
+	for (i = 0; i < disks-2; i++) {
+		if (i == faila)
+			continue;
+		if (blocks[i]) {
+			good = i;
+			good_srcs++;
+			if (good_srcs > 1)
+				break;
+		}
+	}
+	BUG_ON(good_srcs == 0);
+
+	p = blocks[disks-2];
+	p_off = offs[disks-2];
+	q = blocks[disks-1];
+	q_off = offs[disks-1];
+
+	/* Compute syndrome with zero for the missing data page
+	 * Use the dead data page as temporary storage for delta q
+	 */
+	dq = blocks[faila];
+	dq_off = offs[faila];
+	blocks[faila] = NULL;
+	blocks[disks-1] = dq;
+	offs[disks-1] = dq_off;
+
+	/* in the 4-disk case we only need to perform a single source
+	 * multiplication with the one good data block.
+	 */
+	if (good_srcs == 1) {
+		struct page *g = blocks[good];
+		unsigned int g_off = offs[good];
+
+		init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
+				  scribble);
+		tx = async_memcpy(p, g, p_off, g_off, bytes, submit);
+
+		init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
+				  scribble);
+		tx = async_mult(dq, dq_off, g, g_off,
+				raid6_gfexp[good], bytes, submit);
+	} else {
+		init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
+				  scribble);
+		tx = async_gen_syndrome(blocks, offs, disks, bytes, submit);
+	}
+
+	/* Restore pointer table */
+	blocks[faila]   = dq;
+	offs[faila] = dq_off;
+	blocks[disks-1] = q;
+	offs[disks-1] = q_off;
+
+	/* calculate g^{-faila} */
+	coef = raid6_gfinv[raid6_gfexp[faila]];
+
+	srcs[0] = dq;
+	src_offs[0] = dq_off;
+	srcs[1] = q;
+	src_offs[1] = q_off;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor_offs(dq, dq_off, srcs, src_offs, 2, bytes, submit);
+
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_mult(dq, dq_off, dq, dq_off, coef, bytes, submit);
+
+	srcs[0] = p;
+	src_offs[0] = p_off;
+	srcs[1] = dq;
+	src_offs[1] = dq_off;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor_offs(p, p_off, srcs, src_offs, 2, bytes, submit);
+
+	return tx;
+}
+EXPORT_SYMBOL_GPL(async_raid6_datap_recov);
+
+MODULE_AUTHOR("Dan Williams <dan.j.williams@intel.com>");
+MODULE_DESCRIPTION("asynchronous RAID-6 recovery api");
+MODULE_LICENSE("GPL");