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().
  ...

8 files changed, 576 insertions, 0 deletions

diff --git a/arch/mips/dec/prom/Makefile b/arch/mips/dec/prom/Makefile
new file mode 100644
index 000000000..2bad87551
--- /dev/null
+++ b/arch/mips/dec/prom/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the DECstation prom monitor library routines
+# under Linux.
+#
+
+lib-y			+= init.o memory.o cmdline.o identify.o console.o
+
+lib-$(CONFIG_CPU_R3000)	+= locore.o
diff --git a/arch/mips/dec/prom/cmdline.c b/arch/mips/dec/prom/cmdline.c
new file mode 100644
index 000000000..3ed63280a
--- /dev/null
+++ b/arch/mips/dec/prom/cmdline.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cmdline.c: read the command line passed to us by the PROM.
+ *
+ * Copyright (C) 1998 Harald Koerfgen
+ * Copyright (C) 2002, 2004  Maciej W. Rozycki
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/bootinfo.h>
+#include <asm/dec/prom.h>
+
+#undef PROM_DEBUG
+
+void __init prom_init_cmdline(s32 argc, s32 *argv, u32 magic)
+{
+	char *arg;
+	int start_arg, i;
+
+	/*
+	 * collect args and prepare cmd_line
+	 */
+	if (!prom_is_rex(magic))
+		start_arg = 1;
+	else
+		start_arg = 2;
+	for (i = start_arg; i < argc; i++) {
+		arg = (void *)(long)(argv[i]);
+		strcat(arcs_cmdline, arg);
+		if (i < (argc - 1))
+			strcat(arcs_cmdline, " ");
+	}
+
+#ifdef PROM_DEBUG
+	printk("arcs_cmdline: %s\n", &(arcs_cmdline[0]));
+#endif
+}
diff --git a/arch/mips/dec/prom/console.c b/arch/mips/dec/prom/console.c
new file mode 100644
index 000000000..31a8441d8
--- /dev/null
+++ b/arch/mips/dec/prom/console.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	DECstation PROM-based early console support.
+ *
+ *	Copyright (C) 2004, 2007  Maciej W. Rozycki
+ */
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/dec/prom.h>
+
+static void __init prom_console_write(struct console *con, const char *s,
+				      unsigned int c)
+{
+	char buf[81];
+	unsigned int chunk = sizeof(buf) - 1;
+
+	while (c > 0) {
+		if (chunk > c)
+			chunk = c;
+		memcpy(buf, s, chunk);
+		buf[chunk] = '\0';
+		prom_printf("%s", buf);
+		s += chunk;
+		c -= chunk;
+	}
+}
+
+static struct console promcons __initdata = {
+	.name	= "prom",
+	.write	= prom_console_write,
+	.flags	= CON_BOOT | CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+void __init register_prom_console(void)
+{
+	register_console(&promcons);
+}
diff --git a/arch/mips/dec/prom/dectypes.h b/arch/mips/dec/prom/dectypes.h
new file mode 100644
index 000000000..9fcbcc7cd
--- /dev/null
+++ b/arch/mips/dec/prom/dectypes.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DECTYPES
+#define DECTYPES
+
+#define DS2100_3100	1	/* DS2100/3100	Pmax		*/
+#define DS5000_200	2	/* DS5000/200	3max		*/
+#define DS5000_1XX	3	/* DS5000/1xx	kmin		*/
+#define DS5000_2X0	4	/* DS5000/2x0	3max+		*/
+#define DS5800		5	/* DS5800	Isis		*/
+#define DS5400		6	/* DS5400	MIPSfair	*/
+#define DS5000_XX	7	/* DS5000/xx	maxine		*/
+#define DS5500		11	/* DS5500	MIPSfair-2	*/
+#define DS5100		12	/* DS5100	MIPSmate	*/
+
+#endif
diff --git a/arch/mips/dec/prom/identify.c b/arch/mips/dec/prom/identify.c
new file mode 100644
index 000000000..80cd14cd1
--- /dev/null
+++ b/arch/mips/dec/prom/identify.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * identify.c: machine identification code.
+ *
+ * Copyright (C) 1998 Harald Koerfgen and Paul M. Antoine
+ * Copyright (C) 2002, 2003, 2004, 2005  Maciej W. Rozycki
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mc146818rtc.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/bootinfo.h>
+
+#include <asm/dec/ioasic.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/kn01.h>
+#include <asm/dec/kn02.h>
+#include <asm/dec/kn02ba.h>
+#include <asm/dec/kn02ca.h>
+#include <asm/dec/kn03.h>
+#include <asm/dec/kn230.h>
+#include <asm/dec/prom.h>
+#include <asm/dec/system.h>
+
+#include "dectypes.h"
+
+static const char *dec_system_strings[] = {
+	[MACH_DSUNKNOWN]	"unknown DECstation",
+	[MACH_DS23100]		"DECstation 2100/3100",
+	[MACH_DS5100]		"DECsystem 5100",
+	[MACH_DS5000_200]	"DECstation 5000/200",
+	[MACH_DS5000_1XX]	"DECstation 5000/1xx",
+	[MACH_DS5000_XX]	"Personal DECstation 5000/xx",
+	[MACH_DS5000_2X0]	"DECstation 5000/2x0",
+	[MACH_DS5400]		"DECsystem 5400",
+	[MACH_DS5500]		"DECsystem 5500",
+	[MACH_DS5800]		"DECsystem 5800",
+	[MACH_DS5900]		"DECsystem 5900",
+};
+
+const char *get_system_type(void)
+{
+#define STR_BUF_LEN	64
+	static char system[STR_BUF_LEN];
+	static int called = 0;
+
+	if (called == 0) {
+		called = 1;
+		snprintf(system, STR_BUF_LEN, "Digital %s",
+			 dec_system_strings[mips_machtype]);
+	}
+
+	return system;
+}
+
+
+/*
+ * Setup essential system-specific memory addresses.  We need them
+ * early.  Semantically the functions belong to prom/init.c, but they
+ * are compact enough we want them inlined. --macro
+ */
+volatile u8 *dec_rtc_base;
+
+EXPORT_SYMBOL(dec_rtc_base);
+
+static inline void prom_init_kn01(void)
+{
+	dec_kn_slot_base = KN01_SLOT_BASE;
+	dec_kn_slot_size = KN01_SLOT_SIZE;
+
+	dec_rtc_base = (void *)CKSEG1ADDR(dec_kn_slot_base + KN01_RTC);
+}
+
+static inline void prom_init_kn230(void)
+{
+	dec_kn_slot_base = KN01_SLOT_BASE;
+	dec_kn_slot_size = KN01_SLOT_SIZE;
+
+	dec_rtc_base = (void *)CKSEG1ADDR(dec_kn_slot_base + KN01_RTC);
+}
+
+static inline void prom_init_kn02(void)
+{
+	dec_kn_slot_base = KN02_SLOT_BASE;
+	dec_kn_slot_size = KN02_SLOT_SIZE;
+	dec_tc_bus = 1;
+
+	dec_rtc_base = (void *)CKSEG1ADDR(dec_kn_slot_base + KN02_RTC);
+}
+
+static inline void prom_init_kn02xa(void)
+{
+	dec_kn_slot_base = KN02XA_SLOT_BASE;
+	dec_kn_slot_size = IOASIC_SLOT_SIZE;
+	dec_tc_bus = 1;
+
+	ioasic_base = (void *)CKSEG1ADDR(dec_kn_slot_base + IOASIC_IOCTL);
+	dec_rtc_base = (void *)CKSEG1ADDR(dec_kn_slot_base + IOASIC_TOY);
+}
+
+static inline void prom_init_kn03(void)
+{
+	dec_kn_slot_base = KN03_SLOT_BASE;
+	dec_kn_slot_size = IOASIC_SLOT_SIZE;
+	dec_tc_bus = 1;
+
+	ioasic_base = (void *)CKSEG1ADDR(dec_kn_slot_base + IOASIC_IOCTL);
+	dec_rtc_base = (void *)CKSEG1ADDR(dec_kn_slot_base + IOASIC_TOY);
+}
+
+
+void __init prom_identify_arch(u32 magic)
+{
+	unsigned char dec_cpunum, dec_firmrev, dec_etc, dec_systype;
+	u32 dec_sysid;
+
+	if (!prom_is_rex(magic)) {
+		dec_sysid = simple_strtoul(prom_getenv("systype"),
+					   (char **)0, 0);
+	} else {
+		dec_sysid = rex_getsysid();
+		if (dec_sysid == 0) {
+			printk("Zero sysid returned from PROM! "
+			       "Assuming a PMAX-like machine.\n");
+			dec_sysid = 1;
+		}
+	}
+
+	dec_cpunum = (dec_sysid & 0xff000000) >> 24;
+	dec_systype = (dec_sysid & 0xff0000) >> 16;
+	dec_firmrev = (dec_sysid & 0xff00) >> 8;
+	dec_etc = dec_sysid & 0xff;
+
+	/*
+	 * FIXME: This may not be an exhaustive list of DECStations/Servers!
+	 * Put all model-specific initialisation calls here.
+	 */
+	switch (dec_systype) {
+	case DS2100_3100:
+		mips_machtype = MACH_DS23100;
+		prom_init_kn01();
+		break;
+	case DS5100:		/* DS5100 MIPSMATE */
+		mips_machtype = MACH_DS5100;
+		prom_init_kn230();
+		break;
+	case DS5000_200:	/* DS5000 3max */
+		mips_machtype = MACH_DS5000_200;
+		prom_init_kn02();
+		break;
+	case DS5000_1XX:	/* DS5000/100 3min */
+		mips_machtype = MACH_DS5000_1XX;
+		prom_init_kn02xa();
+		break;
+	case DS5000_2X0:	/* DS5000/240 3max+ or DS5900 bigmax */
+		mips_machtype = MACH_DS5000_2X0;
+		prom_init_kn03();
+		if (!(ioasic_read(IO_REG_SIR) & KN03_IO_INR_3MAXP))
+			mips_machtype = MACH_DS5900;
+		break;
+	case DS5000_XX:		/* Personal DS5000/xx maxine */
+		mips_machtype = MACH_DS5000_XX;
+		prom_init_kn02xa();
+		break;
+	case DS5800:		/* DS5800 Isis */
+		mips_machtype = MACH_DS5800;
+		break;
+	case DS5400:		/* DS5400 MIPSfair */
+		mips_machtype = MACH_DS5400;
+		break;
+	case DS5500:		/* DS5500 MIPSfair-2 */
+		mips_machtype = MACH_DS5500;
+		break;
+	default:
+		mips_machtype = MACH_DSUNKNOWN;
+		break;
+	}
+
+	if (mips_machtype == MACH_DSUNKNOWN)
+		printk("This is an %s, id is %x\n",
+		       dec_system_strings[mips_machtype], dec_systype);
+	else
+		printk("This is a %s\n", dec_system_strings[mips_machtype]);
+}
diff --git a/arch/mips/dec/prom/init.c b/arch/mips/dec/prom/init.c
new file mode 100644
index 000000000..cb12eb211
--- /dev/null
+++ b/arch/mips/dec/prom/init.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * init.c: PROM library initialisation code.
+ *
+ * Copyright (C) 1998 Harald Koerfgen
+ * Copyright (C) 2002, 2004  Maciej W. Rozycki
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/linkage.h>
+#include <linux/smp.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/cpu-type.h>
+#include <asm/processor.h>
+
+#include <asm/dec/prom.h>
+
+
+int (*__rex_bootinit)(void);
+int (*__rex_bootread)(void);
+int (*__rex_getbitmap)(memmap *);
+unsigned long *(*__rex_slot_address)(int);
+void *(*__rex_gettcinfo)(void);
+int (*__rex_getsysid)(void);
+void (*__rex_clear_cache)(void);
+
+int (*__prom_getchar)(void);
+char *(*__prom_getenv)(char *);
+int (*__prom_printf)(char *, ...);
+
+int (*__pmax_open)(char*, int);
+int (*__pmax_lseek)(int, long, int);
+int (*__pmax_read)(int, void *, int);
+int (*__pmax_close)(int);
+
+
+/*
+ * Detect which PROM the DECSTATION has, and set the callback vectors
+ * appropriately.
+ */
+void __init which_prom(s32 magic, s32 *prom_vec)
+{
+	/*
+	 * No sign of the REX PROM's magic number means we assume a non-REX
+	 * machine (i.e. we're on a DS2100/3100, DS5100 or DS5000/2xx)
+	 */
+	if (prom_is_rex(magic)) {
+		/*
+		 * Set up prom abstraction structure with REX entry points.
+		 */
+		__rex_bootinit =
+			(void *)(long)*(prom_vec + REX_PROM_BOOTINIT);
+		__rex_bootread =
+			(void *)(long)*(prom_vec + REX_PROM_BOOTREAD);
+		__rex_getbitmap =
+			(void *)(long)*(prom_vec + REX_PROM_GETBITMAP);
+		__prom_getchar =
+			(void *)(long)*(prom_vec + REX_PROM_GETCHAR);
+		__prom_getenv =
+			(void *)(long)*(prom_vec + REX_PROM_GETENV);
+		__rex_getsysid =
+			(void *)(long)*(prom_vec + REX_PROM_GETSYSID);
+		__rex_gettcinfo =
+			(void *)(long)*(prom_vec + REX_PROM_GETTCINFO);
+		__prom_printf =
+			(void *)(long)*(prom_vec + REX_PROM_PRINTF);
+		__rex_slot_address =
+			(void *)(long)*(prom_vec + REX_PROM_SLOTADDR);
+		__rex_clear_cache =
+			(void *)(long)*(prom_vec + REX_PROM_CLEARCACHE);
+	} else {
+		/*
+		 * Set up prom abstraction structure with non-REX entry points.
+		 */
+		__prom_getchar = (void *)PMAX_PROM_GETCHAR;
+		__prom_getenv = (void *)PMAX_PROM_GETENV;
+		__prom_printf = (void *)PMAX_PROM_PRINTF;
+		__pmax_open = (void *)PMAX_PROM_OPEN;
+		__pmax_lseek = (void *)PMAX_PROM_LSEEK;
+		__pmax_read = (void *)PMAX_PROM_READ;
+		__pmax_close = (void *)PMAX_PROM_CLOSE;
+	}
+}
+
+void __init prom_init(void)
+{
+	extern void dec_machine_halt(void);
+	static const char cpu_msg[] __initconst =
+		"Sorry, this kernel is compiled for a wrong CPU type!\n";
+	s32 argc = fw_arg0;
+	s32 *argv = (void *)fw_arg1;
+	u32 magic = fw_arg2;
+	s32 *prom_vec = (void *)fw_arg3;
+
+	/*
+	 * Determine which PROM we have
+	 * (and therefore which machine we're on!)
+	 */
+	which_prom(magic, prom_vec);
+
+	if (prom_is_rex(magic))
+		rex_clear_cache();
+
+	/* Register the early console.  */
+	register_prom_console();
+
+	/* Were we compiled with the right CPU option? */
+#if defined(CONFIG_CPU_R3000)
+	if ((current_cpu_type() == CPU_R4000SC) ||
+	    (current_cpu_type() == CPU_R4400SC)) {
+		static const char r4k_msg[] __initconst =
+			"Please recompile with \"CONFIG_CPU_R4X00 = y\".\n";
+		printk(cpu_msg);
+		printk(r4k_msg);
+		dec_machine_halt();
+	}
+#endif
+
+#if defined(CONFIG_CPU_R4X00)
+	if ((current_cpu_type() == CPU_R3000) ||
+	    (current_cpu_type() == CPU_R3000A)) {
+		static const char r3k_msg[] __initconst =
+			"Please recompile with \"CONFIG_CPU_R3000 = y\".\n";
+		printk(cpu_msg);
+		printk(r3k_msg);
+		dec_machine_halt();
+	}
+#endif
+
+	prom_meminit(magic);
+	prom_identify_arch(magic);
+	prom_init_cmdline(argc, argv, magic);
+}
diff --git a/arch/mips/dec/prom/locore.S b/arch/mips/dec/prom/locore.S
new file mode 100644
index 000000000..0eb8fab62
--- /dev/null
+++ b/arch/mips/dec/prom/locore.S
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * locore.S
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+#include <asm/mipsregs.h>
+
+	.text
+
+/*
+ * Simple general exception handling routine. This one is used for the
+ * Memory sizing routine for pmax machines. HK
+ */
+
+NESTED(genexcept_early, 0, sp)
+	.set	noat
+	.set	noreorder
+
+	mfc0	k0, CP0_STATUS
+	la	k1, mem_err
+
+	sw	k0, 0(k1)
+
+	mfc0	k0, CP0_EPC
+	nop
+	addiu	k0, 4		# skip the causing instruction
+	jr	k0
+	 rfe
+END(genexcept_early)
diff --git a/arch/mips/dec/prom/memory.c b/arch/mips/dec/prom/memory.c
new file mode 100644
index 000000000..44490c30d
--- /dev/null
+++ b/arch/mips/dec/prom/memory.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * memory.c: memory initialisation code.
+ *
+ * Copyright (C) 1998 Harald Koerfgen, Frieder Streffer and Paul M. Antoine
+ * Copyright (C) 2000, 2002  Maciej W. Rozycki
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/memblock.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/dec/machtype.h>
+#include <asm/dec/prom.h>
+#include <asm/page.h>
+#include <asm/sections.h>
+
+
+volatile unsigned long mem_err;		/* So we know an error occurred */
+
+/*
+ * Probe memory in 4MB chunks, waiting for an error to tell us we've fallen
+ * off the end of real memory.  Only suitable for the 2100/3100's (PMAX).
+ */
+
+#define CHUNK_SIZE 0x400000
+
+static __init void pmax_setup_memory_region(void)
+{
+	volatile unsigned char *memory_page, dummy;
+	char old_handler[0x80];
+	extern char genexcept_early;
+
+	/* Install exception handler */
+	memcpy(&old_handler, (void *)(CKSEG0 + 0x80), 0x80);
+	memcpy((void *)(CKSEG0 + 0x80), &genexcept_early, 0x80);
+
+	/* read unmapped and uncached (KSEG1)
+	 * DECstations have at least 4MB RAM
+	 * Assume less than 480MB of RAM, as this is max for 5000/2xx
+	 * FIXME this should be replaced by the first free page!
+	 */
+	for (memory_page = (unsigned char *)CKSEG1 + CHUNK_SIZE;
+	     mem_err == 0 && memory_page < (unsigned char *)CKSEG1 + 0x1e00000;
+	     memory_page += CHUNK_SIZE) {
+		dummy = *memory_page;
+	}
+	memcpy((void *)(CKSEG0 + 0x80), &old_handler, 0x80);
+
+	memblock_add(0, (unsigned long)memory_page - CKSEG1 - CHUNK_SIZE);
+}
+
+/*
+ * Use the REX prom calls to get hold of the memory bitmap, and thence
+ * determine memory size.
+ */
+static __init void rex_setup_memory_region(void)
+{
+	int i, bitmap_size;
+	unsigned long mem_start = 0, mem_size = 0;
+	memmap *bm;
+
+	/* some free 64k */
+	bm = (memmap *)CKSEG0ADDR(0x28000);
+
+	bitmap_size = rex_getbitmap(bm);
+
+	for (i = 0; i < bitmap_size; i++) {
+		/* FIXME: very simplistically only add full sets of pages */
+		if (bm->bitmap[i] == 0xff)
+			mem_size += (8 * bm->pagesize);
+		else if (!mem_size)
+			mem_start += (8 * bm->pagesize);
+		else {
+			memblock_add(mem_start, mem_size);
+			mem_start += mem_size + (8 * bm->pagesize);
+			mem_size = 0;
+		}
+	}
+	if (mem_size)
+		memblock_add(mem_start, mem_size);
+}
+
+void __init prom_meminit(u32 magic)
+{
+	if (!prom_is_rex(magic))
+		pmax_setup_memory_region();
+	else
+		rex_setup_memory_region();
+}
+
+void __init prom_free_prom_memory(void)
+{
+	unsigned long end;
+
+	/*
+	 * Free everything below the kernel itself but leave
+	 * the first page reserved for the exception handlers.
+	 */
+
+#if IS_ENABLED(CONFIG_DECLANCE)
+	/*
+	 * Leave 128 KB reserved for Lance memory for
+	 * IOASIC DECstations.
+	 *
+	 * XXX: save this address for use in dec_lance.c?
+	 */
+	if (IOASIC)
+		end = __pa(&_text) - 0x00020000;
+	else
+#endif
+		end = __pa(&_text);
+
+	free_init_pages("unused PROM memory", PAGE_SIZE, end);
+}