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, 870 insertions, 0 deletions

diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
new file mode 100644
index 000000000..73e408146
--- /dev/null
+++ b/drivers/char/hw_random/n2-drv.c
@@ -0,0 +1,870 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* n2-drv.c: Niagara-2 RNG driver.
+ *
+ * Copyright (C) 2008, 2011 David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/preempt.h>
+#include <linux/hw_random.h>
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/hypervisor.h>
+
+#include "n2rng.h"
+
+#define DRV_MODULE_NAME		"n2rng"
+#define PFX DRV_MODULE_NAME	": "
+#define DRV_MODULE_VERSION	"0.3"
+#define DRV_MODULE_RELDATE	"Jan 7, 2017"
+
+static char version[] =
+	DRV_MODULE_NAME " v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
+
+MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
+MODULE_DESCRIPTION("Niagara2 RNG driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_MODULE_VERSION);
+
+/* The Niagara2 RNG provides a 64-bit read-only random number
+ * register, plus a control register.  Access to the RNG is
+ * virtualized through the hypervisor so that both guests and control
+ * nodes can access the device.
+ *
+ * The entropy source consists of raw entropy sources, each
+ * constructed from a voltage controlled oscillator whose phase is
+ * jittered by thermal noise sources.
+ *
+ * The oscillator in each of the three raw entropy sources run at
+ * different frequencies.  Normally, all three generator outputs are
+ * gathered, xored together, and fed into a CRC circuit, the output of
+ * which is the 64-bit read-only register.
+ *
+ * Some time is necessary for all the necessary entropy to build up
+ * such that a full 64-bits of entropy are available in the register.
+ * In normal operating mode (RNG_CTL_LFSR is set), the chip implements
+ * an interlock which blocks register reads until sufficient entropy
+ * is available.
+ *
+ * A control register is provided for adjusting various aspects of RNG
+ * operation, and to enable diagnostic modes.  Each of the three raw
+ * entropy sources has an enable bit (RNG_CTL_ES{1,2,3}).  Also
+ * provided are fields for controlling the minimum time in cycles
+ * between read accesses to the register (RNG_CTL_WAIT, this controls
+ * the interlock described in the previous paragraph).
+ *
+ * The standard setting is to have the mode bit (RNG_CTL_LFSR) set,
+ * all three entropy sources enabled, and the interlock time set
+ * appropriately.
+ *
+ * The CRC polynomial used by the chip is:
+ *
+ * P(X) = x64 + x61 + x57 + x56 + x52 + x51 + x50 + x48 + x47 + x46 +
+ *        x43 + x42 + x41 + x39 + x38 + x37 + x35 + x32 + x28 + x25 +
+ *        x22 + x21 + x17 + x15 + x13 + x12 + x11 + x7 + x5 + x + 1
+ *
+ * The RNG_CTL_VCO value of each noise cell must be programmed
+ * separately.  This is why 4 control register values must be provided
+ * to the hypervisor.  During a write, the hypervisor writes them all,
+ * one at a time, to the actual RNG_CTL register.  The first three
+ * values are used to setup the desired RNG_CTL_VCO for each entropy
+ * source, for example:
+ *
+ *	control 0: (1 << RNG_CTL_VCO_SHIFT) | RNG_CTL_ES1
+ *	control 1: (2 << RNG_CTL_VCO_SHIFT) | RNG_CTL_ES2
+ *	control 2: (3 << RNG_CTL_VCO_SHIFT) | RNG_CTL_ES3
+ *
+ * And then the fourth value sets the final chip state and enables
+ * desired.
+ */
+
+static int n2rng_hv_err_trans(unsigned long hv_err)
+{
+	switch (hv_err) {
+	case HV_EOK:
+		return 0;
+	case HV_EWOULDBLOCK:
+		return -EAGAIN;
+	case HV_ENOACCESS:
+		return -EPERM;
+	case HV_EIO:
+		return -EIO;
+	case HV_EBUSY:
+		return -EBUSY;
+	case HV_EBADALIGN:
+	case HV_ENORADDR:
+		return -EFAULT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static unsigned long n2rng_generic_read_control_v2(unsigned long ra,
+						   unsigned long unit)
+{
+	unsigned long hv_err, state, ticks, watchdog_delta, watchdog_status;
+	int block = 0, busy = 0;
+
+	while (1) {
+		hv_err = sun4v_rng_ctl_read_v2(ra, unit, &state,
+					       &ticks,
+					       &watchdog_delta,
+					       &watchdog_status);
+		if (hv_err == HV_EOK)
+			break;
+
+		if (hv_err == HV_EBUSY) {
+			if (++busy >= N2RNG_BUSY_LIMIT)
+				break;
+
+			udelay(1);
+		} else if (hv_err == HV_EWOULDBLOCK) {
+			if (++block >= N2RNG_BLOCK_LIMIT)
+				break;
+
+			__delay(ticks);
+		} else
+			break;
+	}
+
+	return hv_err;
+}
+
+/* In multi-socket situations, the hypervisor might need to
+ * queue up the RNG control register write if it's for a unit
+ * that is on a cpu socket other than the one we are executing on.
+ *
+ * We poll here waiting for a successful read of that control
+ * register to make sure the write has been actually performed.
+ */
+static unsigned long n2rng_control_settle_v2(struct n2rng *np, int unit)
+{
+	unsigned long ra = __pa(&np->scratch_control[0]);
+
+	return n2rng_generic_read_control_v2(ra, unit);
+}
+
+static unsigned long n2rng_write_ctl_one(struct n2rng *np, int unit,
+					 unsigned long state,
+					 unsigned long control_ra,
+					 unsigned long watchdog_timeout,
+					 unsigned long *ticks)
+{
+	unsigned long hv_err;
+
+	if (np->hvapi_major == 1) {
+		hv_err = sun4v_rng_ctl_write_v1(control_ra, state,
+						watchdog_timeout, ticks);
+	} else {
+		hv_err = sun4v_rng_ctl_write_v2(control_ra, state,
+						watchdog_timeout, unit);
+		if (hv_err == HV_EOK)
+			hv_err = n2rng_control_settle_v2(np, unit);
+		*ticks = N2RNG_ACCUM_CYCLES_DEFAULT;
+	}
+
+	return hv_err;
+}
+
+static int n2rng_generic_read_data(unsigned long data_ra)
+{
+	unsigned long ticks, hv_err;
+	int block = 0, hcheck = 0;
+
+	while (1) {
+		hv_err = sun4v_rng_data_read(data_ra, &ticks);
+		if (hv_err == HV_EOK)
+			return 0;
+
+		if (hv_err == HV_EWOULDBLOCK) {
+			if (++block >= N2RNG_BLOCK_LIMIT)
+				return -EWOULDBLOCK;
+			__delay(ticks);
+		} else if (hv_err == HV_ENOACCESS) {
+			return -EPERM;
+		} else if (hv_err == HV_EIO) {
+			if (++hcheck >= N2RNG_HCHECK_LIMIT)
+				return -EIO;
+			udelay(10000);
+		} else
+			return -ENODEV;
+	}
+}
+
+static unsigned long n2rng_read_diag_data_one(struct n2rng *np,
+					      unsigned long unit,
+					      unsigned long data_ra,
+					      unsigned long data_len,
+					      unsigned long *ticks)
+{
+	unsigned long hv_err;
+
+	if (np->hvapi_major == 1) {
+		hv_err = sun4v_rng_data_read_diag_v1(data_ra, data_len, ticks);
+	} else {
+		hv_err = sun4v_rng_data_read_diag_v2(data_ra, data_len,
+						     unit, ticks);
+		if (!*ticks)
+			*ticks = N2RNG_ACCUM_CYCLES_DEFAULT;
+	}
+	return hv_err;
+}
+
+static int n2rng_generic_read_diag_data(struct n2rng *np,
+					unsigned long unit,
+					unsigned long data_ra,
+					unsigned long data_len)
+{
+	unsigned long ticks, hv_err;
+	int block = 0;
+
+	while (1) {
+		hv_err = n2rng_read_diag_data_one(np, unit,
+						  data_ra, data_len,
+						  &ticks);
+		if (hv_err == HV_EOK)
+			return 0;
+
+		if (hv_err == HV_EWOULDBLOCK) {
+			if (++block >= N2RNG_BLOCK_LIMIT)
+				return -EWOULDBLOCK;
+			__delay(ticks);
+		} else if (hv_err == HV_ENOACCESS) {
+			return -EPERM;
+		} else if (hv_err == HV_EIO) {
+			return -EIO;
+		} else
+			return -ENODEV;
+	}
+}
+
+
+static int n2rng_generic_write_control(struct n2rng *np,
+				       unsigned long control_ra,
+				       unsigned long unit,
+				       unsigned long state)
+{
+	unsigned long hv_err, ticks;
+	int block = 0, busy = 0;
+
+	while (1) {
+		hv_err = n2rng_write_ctl_one(np, unit, state, control_ra,
+					     np->wd_timeo, &ticks);
+		if (hv_err == HV_EOK)
+			return 0;
+
+		if (hv_err == HV_EWOULDBLOCK) {
+			if (++block >= N2RNG_BLOCK_LIMIT)
+				return -EWOULDBLOCK;
+			__delay(ticks);
+		} else if (hv_err == HV_EBUSY) {
+			if (++busy >= N2RNG_BUSY_LIMIT)
+				return -EBUSY;
+			udelay(1);
+		} else
+			return -ENODEV;
+	}
+}
+
+/* Just try to see if we can successfully access the control register
+ * of the RNG on the domain on which we are currently executing.
+ */
+static int n2rng_try_read_ctl(struct n2rng *np)
+{
+	unsigned long hv_err;
+	unsigned long x;
+
+	if (np->hvapi_major == 1) {
+		hv_err = sun4v_rng_get_diag_ctl();
+	} else {
+		/* We purposefully give invalid arguments, HV_NOACCESS
+		 * is higher priority than the errors we'd get from
+		 * these other cases, and that's the error we are
+		 * truly interested in.
+		 */
+		hv_err = sun4v_rng_ctl_read_v2(0UL, ~0UL, &x, &x, &x, &x);
+		switch (hv_err) {
+		case HV_EWOULDBLOCK:
+		case HV_ENOACCESS:
+			break;
+		default:
+			hv_err = HV_EOK;
+			break;
+		}
+	}
+
+	return n2rng_hv_err_trans(hv_err);
+}
+
+static u64 n2rng_control_default(struct n2rng *np, int ctl)
+{
+	u64 val = 0;
+
+	if (np->data->chip_version == 1) {
+		val = ((2 << RNG_v1_CTL_ASEL_SHIFT) |
+			(N2RNG_ACCUM_CYCLES_DEFAULT << RNG_v1_CTL_WAIT_SHIFT) |
+			 RNG_CTL_LFSR);
+
+		switch (ctl) {
+		case 0:
+			val |= (1 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES1;
+			break;
+		case 1:
+			val |= (2 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES2;
+			break;
+		case 2:
+			val |= (3 << RNG_v1_CTL_VCO_SHIFT) | RNG_CTL_ES3;
+			break;
+		case 3:
+			val |= RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3;
+			break;
+		default:
+			break;
+		}
+
+	} else {
+		val = ((2 << RNG_v2_CTL_ASEL_SHIFT) |
+			(N2RNG_ACCUM_CYCLES_DEFAULT << RNG_v2_CTL_WAIT_SHIFT) |
+			 RNG_CTL_LFSR);
+
+		switch (ctl) {
+		case 0:
+			val |= (1 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES1;
+			break;
+		case 1:
+			val |= (2 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES2;
+			break;
+		case 2:
+			val |= (3 << RNG_v2_CTL_VCO_SHIFT) | RNG_CTL_ES3;
+			break;
+		case 3:
+			val |= RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return val;
+}
+
+static void n2rng_control_swstate_init(struct n2rng *np)
+{
+	int i;
+
+	np->flags |= N2RNG_FLAG_CONTROL;
+
+	np->health_check_sec = N2RNG_HEALTH_CHECK_SEC_DEFAULT;
+	np->accum_cycles = N2RNG_ACCUM_CYCLES_DEFAULT;
+	np->wd_timeo = N2RNG_WD_TIMEO_DEFAULT;
+
+	for (i = 0; i < np->num_units; i++) {
+		struct n2rng_unit *up = &np->units[i];
+
+		up->control[0] = n2rng_control_default(np, 0);
+		up->control[1] = n2rng_control_default(np, 1);
+		up->control[2] = n2rng_control_default(np, 2);
+		up->control[3] = n2rng_control_default(np, 3);
+	}
+
+	np->hv_state = HV_RNG_STATE_UNCONFIGURED;
+}
+
+static int n2rng_grab_diag_control(struct n2rng *np)
+{
+	int i, busy_count, err = -ENODEV;
+
+	busy_count = 0;
+	for (i = 0; i < 100; i++) {
+		err = n2rng_try_read_ctl(np);
+		if (err != -EAGAIN)
+			break;
+
+		if (++busy_count > 100) {
+			dev_err(&np->op->dev,
+				"Grab diag control timeout.\n");
+			return -ENODEV;
+		}
+
+		udelay(1);
+	}
+
+	return err;
+}
+
+static int n2rng_init_control(struct n2rng *np)
+{
+	int err = n2rng_grab_diag_control(np);
+
+	/* Not in the control domain, that's OK we are only a consumer
+	 * of the RNG data, we don't setup and program it.
+	 */
+	if (err == -EPERM)
+		return 0;
+	if (err)
+		return err;
+
+	n2rng_control_swstate_init(np);
+
+	return 0;
+}
+
+static int n2rng_data_read(struct hwrng *rng, u32 *data)
+{
+	struct n2rng *np = (struct n2rng *) rng->priv;
+	unsigned long ra = __pa(&np->test_data);
+	int len;
+
+	if (!(np->flags & N2RNG_FLAG_READY)) {
+		len = 0;
+	} else if (np->flags & N2RNG_FLAG_BUFFER_VALID) {
+		np->flags &= ~N2RNG_FLAG_BUFFER_VALID;
+		*data = np->buffer;
+		len = 4;
+	} else {
+		int err = n2rng_generic_read_data(ra);
+		if (!err) {
+			np->flags |= N2RNG_FLAG_BUFFER_VALID;
+			np->buffer = np->test_data >> 32;
+			*data = np->test_data & 0xffffffff;
+			len = 4;
+		} else {
+			dev_err(&np->op->dev, "RNG error, retesting\n");
+			np->flags &= ~N2RNG_FLAG_READY;
+			if (!(np->flags & N2RNG_FLAG_SHUTDOWN))
+				schedule_delayed_work(&np->work, 0);
+			len = 0;
+		}
+	}
+
+	return len;
+}
+
+/* On a guest node, just make sure we can read random data properly.
+ * If a control node reboots or reloads it's n2rng driver, this won't
+ * work during that time.  So we have to keep probing until the device
+ * becomes usable.
+ */
+static int n2rng_guest_check(struct n2rng *np)
+{
+	unsigned long ra = __pa(&np->test_data);
+
+	return n2rng_generic_read_data(ra);
+}
+
+static int n2rng_entropy_diag_read(struct n2rng *np, unsigned long unit,
+				   u64 *pre_control, u64 pre_state,
+				   u64 *buffer, unsigned long buf_len,
+				   u64 *post_control, u64 post_state)
+{
+	unsigned long post_ctl_ra = __pa(post_control);
+	unsigned long pre_ctl_ra = __pa(pre_control);
+	unsigned long buffer_ra = __pa(buffer);
+	int err;
+
+	err = n2rng_generic_write_control(np, pre_ctl_ra, unit, pre_state);
+	if (err)
+		return err;
+
+	err = n2rng_generic_read_diag_data(np, unit,
+					   buffer_ra, buf_len);
+
+	(void) n2rng_generic_write_control(np, post_ctl_ra, unit,
+					   post_state);
+
+	return err;
+}
+
+static u64 advance_polynomial(u64 poly, u64 val, int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		int highbit_set = ((s64)val < 0);
+
+		val <<= 1;
+		if (highbit_set)
+			val ^= poly;
+	}
+
+	return val;
+}
+
+static int n2rng_test_buffer_find(struct n2rng *np, u64 val)
+{
+	int i, count = 0;
+
+	/* Purposefully skip over the first word.  */
+	for (i = 1; i < SELFTEST_BUFFER_WORDS; i++) {
+		if (np->test_buffer[i] == val)
+			count++;
+	}
+	return count;
+}
+
+static void n2rng_dump_test_buffer(struct n2rng *np)
+{
+	int i;
+
+	for (i = 0; i < SELFTEST_BUFFER_WORDS; i++)
+		dev_err(&np->op->dev, "Test buffer slot %d [0x%016llx]\n",
+			i, np->test_buffer[i]);
+}
+
+static int n2rng_check_selftest_buffer(struct n2rng *np, unsigned long unit)
+{
+	u64 val;
+	int err, matches, limit;
+
+	switch (np->data->id) {
+	case N2_n2_rng:
+	case N2_vf_rng:
+	case N2_kt_rng:
+	case N2_m4_rng:  /* yes, m4 uses the old value */
+		val = RNG_v1_SELFTEST_VAL;
+		break;
+	default:
+		val = RNG_v2_SELFTEST_VAL;
+		break;
+	}
+
+	matches = 0;
+	for (limit = 0; limit < SELFTEST_LOOPS_MAX; limit++) {
+		matches += n2rng_test_buffer_find(np, val);
+		if (matches >= SELFTEST_MATCH_GOAL)
+			break;
+		val = advance_polynomial(SELFTEST_POLY, val, 1);
+	}
+
+	err = 0;
+	if (limit >= SELFTEST_LOOPS_MAX) {
+		err = -ENODEV;
+		dev_err(&np->op->dev, "Selftest failed on unit %lu\n", unit);
+		n2rng_dump_test_buffer(np);
+	} else
+		dev_info(&np->op->dev, "Selftest passed on unit %lu\n", unit);
+
+	return err;
+}
+
+static int n2rng_control_selftest(struct n2rng *np, unsigned long unit)
+{
+	int err;
+	u64 base, base3;
+
+	switch (np->data->id) {
+	case N2_n2_rng:
+	case N2_vf_rng:
+	case N2_kt_rng:
+		base = RNG_v1_CTL_ASEL_NOOUT << RNG_v1_CTL_ASEL_SHIFT;
+		base3 = base | RNG_CTL_LFSR |
+			((RNG_v1_SELFTEST_TICKS - 2) << RNG_v1_CTL_WAIT_SHIFT);
+		break;
+	case N2_m4_rng:
+		base = RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT;
+		base3 = base | RNG_CTL_LFSR |
+			((RNG_v1_SELFTEST_TICKS - 2) << RNG_v2_CTL_WAIT_SHIFT);
+		break;
+	default:
+		base = RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT;
+		base3 = base | RNG_CTL_LFSR |
+			(RNG_v2_SELFTEST_TICKS << RNG_v2_CTL_WAIT_SHIFT);
+		break;
+	}
+
+	np->test_control[0] = base;
+	np->test_control[1] = base;
+	np->test_control[2] = base;
+	np->test_control[3] = base3;
+
+	err = n2rng_entropy_diag_read(np, unit, np->test_control,
+				      HV_RNG_STATE_HEALTHCHECK,
+				      np->test_buffer,
+				      sizeof(np->test_buffer),
+				      &np->units[unit].control[0],
+				      np->hv_state);
+	if (err)
+		return err;
+
+	return n2rng_check_selftest_buffer(np, unit);
+}
+
+static int n2rng_control_check(struct n2rng *np)
+{
+	int i;
+
+	for (i = 0; i < np->num_units; i++) {
+		int err = n2rng_control_selftest(np, i);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+/* The sanity checks passed, install the final configuration into the
+ * chip, it's ready to use.
+ */
+static int n2rng_control_configure_units(struct n2rng *np)
+{
+	int unit, err;
+
+	err = 0;
+	for (unit = 0; unit < np->num_units; unit++) {
+		struct n2rng_unit *up = &np->units[unit];
+		unsigned long ctl_ra = __pa(&up->control[0]);
+		int esrc;
+		u64 base, shift;
+
+		if (np->data->chip_version == 1) {
+			base = ((np->accum_cycles << RNG_v1_CTL_WAIT_SHIFT) |
+			      (RNG_v1_CTL_ASEL_NOOUT << RNG_v1_CTL_ASEL_SHIFT) |
+			      RNG_CTL_LFSR);
+			shift = RNG_v1_CTL_VCO_SHIFT;
+		} else {
+			base = ((np->accum_cycles << RNG_v2_CTL_WAIT_SHIFT) |
+			      (RNG_v2_CTL_ASEL_NOOUT << RNG_v2_CTL_ASEL_SHIFT) |
+			      RNG_CTL_LFSR);
+			shift = RNG_v2_CTL_VCO_SHIFT;
+		}
+
+		/* XXX This isn't the best.  We should fetch a bunch
+		 * XXX of words using each entropy source combined XXX
+		 * with each VCO setting, and see which combinations
+		 * XXX give the best random data.
+		 */
+		for (esrc = 0; esrc < 3; esrc++)
+			up->control[esrc] = base |
+				(esrc << shift) |
+				(RNG_CTL_ES1 << esrc);
+
+		up->control[3] = base |
+			(RNG_CTL_ES1 | RNG_CTL_ES2 | RNG_CTL_ES3);
+
+		err = n2rng_generic_write_control(np, ctl_ra, unit,
+						  HV_RNG_STATE_CONFIGURED);
+		if (err)
+			break;
+	}
+
+	return err;
+}
+
+static void n2rng_work(struct work_struct *work)
+{
+	struct n2rng *np = container_of(work, struct n2rng, work.work);
+	int err = 0;
+	static int retries = 4;
+
+	if (!(np->flags & N2RNG_FLAG_CONTROL)) {
+		err = n2rng_guest_check(np);
+	} else {
+		preempt_disable();
+		err = n2rng_control_check(np);
+		preempt_enable();
+
+		if (!err)
+			err = n2rng_control_configure_units(np);
+	}
+
+	if (!err) {
+		np->flags |= N2RNG_FLAG_READY;
+		dev_info(&np->op->dev, "RNG ready\n");
+	}
+
+	if (--retries == 0)
+		dev_err(&np->op->dev, "Self-test retries failed, RNG not ready\n");
+	else if (err && !(np->flags & N2RNG_FLAG_SHUTDOWN))
+		schedule_delayed_work(&np->work, HZ * 2);
+}
+
+static void n2rng_driver_version(void)
+{
+	static int n2rng_version_printed;
+
+	if (n2rng_version_printed++ == 0)
+		pr_info("%s", version);
+}
+
+static const struct of_device_id n2rng_match[];
+static int n2rng_probe(struct platform_device *op)
+{
+	const struct of_device_id *match;
+	int err = -ENOMEM;
+	struct n2rng *np;
+
+	match = of_match_device(n2rng_match, &op->dev);
+	if (!match)
+		return -EINVAL;
+
+	n2rng_driver_version();
+	np = devm_kzalloc(&op->dev, sizeof(*np), GFP_KERNEL);
+	if (!np)
+		goto out;
+	np->op = op;
+	np->data = (struct n2rng_template *)match->data;
+
+	INIT_DELAYED_WORK(&np->work, n2rng_work);
+
+	if (np->data->multi_capable)
+		np->flags |= N2RNG_FLAG_MULTI;
+
+	err = -ENODEV;
+	np->hvapi_major = 2;
+	if (sun4v_hvapi_register(HV_GRP_RNG,
+				 np->hvapi_major,
+				 &np->hvapi_minor)) {
+		np->hvapi_major = 1;
+		if (sun4v_hvapi_register(HV_GRP_RNG,
+					 np->hvapi_major,
+					 &np->hvapi_minor)) {
+			dev_err(&op->dev, "Cannot register suitable "
+				"HVAPI version.\n");
+			goto out;
+		}
+	}
+
+	if (np->flags & N2RNG_FLAG_MULTI) {
+		if (np->hvapi_major < 2) {
+			dev_err(&op->dev, "multi-unit-capable RNG requires "
+				"HVAPI major version 2 or later, got %lu\n",
+				np->hvapi_major);
+			goto out_hvapi_unregister;
+		}
+		np->num_units = of_getintprop_default(op->dev.of_node,
+						      "rng-#units", 0);
+		if (!np->num_units) {
+			dev_err(&op->dev, "VF RNG lacks rng-#units property\n");
+			goto out_hvapi_unregister;
+		}
+	} else {
+		np->num_units = 1;
+	}
+
+	dev_info(&op->dev, "Registered RNG HVAPI major %lu minor %lu\n",
+		 np->hvapi_major, np->hvapi_minor);
+	np->units = devm_kcalloc(&op->dev, np->num_units, sizeof(*np->units),
+				 GFP_KERNEL);
+	err = -ENOMEM;
+	if (!np->units)
+		goto out_hvapi_unregister;
+
+	err = n2rng_init_control(np);
+	if (err)
+		goto out_hvapi_unregister;
+
+	dev_info(&op->dev, "Found %s RNG, units: %d\n",
+		 ((np->flags & N2RNG_FLAG_MULTI) ?
+		  "multi-unit-capable" : "single-unit"),
+		 np->num_units);
+
+	np->hwrng.name = DRV_MODULE_NAME;
+	np->hwrng.data_read = n2rng_data_read;
+	np->hwrng.priv = (unsigned long) np;
+
+	err = devm_hwrng_register(&op->dev, &np->hwrng);
+	if (err)
+		goto out_hvapi_unregister;
+
+	platform_set_drvdata(op, np);
+
+	schedule_delayed_work(&np->work, 0);
+
+	return 0;
+
+out_hvapi_unregister:
+	sun4v_hvapi_unregister(HV_GRP_RNG);
+
+out:
+	return err;
+}
+
+static int n2rng_remove(struct platform_device *op)
+{
+	struct n2rng *np = platform_get_drvdata(op);
+
+	np->flags |= N2RNG_FLAG_SHUTDOWN;
+
+	cancel_delayed_work_sync(&np->work);
+
+	sun4v_hvapi_unregister(HV_GRP_RNG);
+
+	return 0;
+}
+
+static struct n2rng_template n2_template = {
+	.id = N2_n2_rng,
+	.multi_capable = 0,
+	.chip_version = 1,
+};
+
+static struct n2rng_template vf_template = {
+	.id = N2_vf_rng,
+	.multi_capable = 1,
+	.chip_version = 1,
+};
+
+static struct n2rng_template kt_template = {
+	.id = N2_kt_rng,
+	.multi_capable = 1,
+	.chip_version = 1,
+};
+
+static struct n2rng_template m4_template = {
+	.id = N2_m4_rng,
+	.multi_capable = 1,
+	.chip_version = 2,
+};
+
+static struct n2rng_template m7_template = {
+	.id = N2_m7_rng,
+	.multi_capable = 1,
+	.chip_version = 2,
+};
+
+static const struct of_device_id n2rng_match[] = {
+	{
+		.name		= "random-number-generator",
+		.compatible	= "SUNW,n2-rng",
+		.data		= &n2_template,
+	},
+	{
+		.name		= "random-number-generator",
+		.compatible	= "SUNW,vf-rng",
+		.data		= &vf_template,
+	},
+	{
+		.name		= "random-number-generator",
+		.compatible	= "SUNW,kt-rng",
+		.data		= &kt_template,
+	},
+	{
+		.name		= "random-number-generator",
+		.compatible	= "ORCL,m4-rng",
+		.data		= &m4_template,
+	},
+	{
+		.name		= "random-number-generator",
+		.compatible	= "ORCL,m7-rng",
+		.data		= &m7_template,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, n2rng_match);
+
+static struct platform_driver n2rng_driver = {
+	.driver = {
+		.name = "n2rng",
+		.of_match_table = n2rng_match,
+	},
+	.probe		= n2rng_probe,
+	.remove		= n2rng_remove,
+};
+
+module_platform_driver(n2rng_driver);