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, 847 insertions, 0 deletions

diff --git a/drivers/mtd/devices/pmc551.c b/drivers/mtd/devices/pmc551.c
new file mode 100644
index 000000000..6597fc2aa
--- /dev/null
+++ b/drivers/mtd/devices/pmc551.c
@@ -0,0 +1,847 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PMC551 PCI Mezzanine Ram Device
+ *
+ * Author:
+ *	Mark Ferrell <mferrell@mvista.com>
+ *	Copyright 1999,2000 Nortel Networks
+ *
+ * Description:
+ *	This driver is intended to support the PMC551 PCI Ram device
+ *	from Ramix Inc.  The PMC551 is a PMC Mezzanine module for
+ *	cPCI embedded systems.  The device contains a single SROM
+ *	that initially programs the V370PDC chipset onboard the
+ *	device, and various banks of DRAM/SDRAM onboard.  This driver
+ *	implements this PCI Ram device as an MTD (Memory Technology
+ *	Device) so that it can be used to hold a file system, or for
+ *	added swap space in embedded systems.  Since the memory on
+ *	this board isn't as fast as main memory we do not try to hook
+ *	it into main memory as that would simply reduce performance
+ *	on the system.  Using it as a block device allows us to use
+ *	it as high speed swap or for a high speed disk device of some
+ *	sort.  Which becomes very useful on diskless systems in the
+ *	embedded market I might add.
+ *
+ * Notes:
+ *	Due to what I assume is more buggy SROM, the 64M PMC551 I
+ *	have available claims that all 4 of its DRAM banks have 64MiB
+ *	of ram configured (making a grand total of 256MiB onboard).
+ *	This is slightly annoying since the BAR0 size reflects the
+ *	aperture size, not the dram size, and the V370PDC supplies no
+ *	other method for memory size discovery.  This problem is
+ *	mostly only relevant when compiled as a module, as the
+ *	unloading of the module with an aperture size smaller than
+ *	the ram will cause the driver to detect the onboard memory
+ *	size to be equal to the aperture size when the module is
+ *	reloaded.  Soooo, to help, the module supports an msize
+ *	option to allow the specification of the onboard memory, and
+ *	an asize option, to allow the specification of the aperture
+ *	size.  The aperture must be equal to or less then the memory
+ *	size, the driver will correct this if you screw it up.  This
+ *	problem is not relevant for compiled in drivers as compiled
+ *	in drivers only init once.
+ *
+ * Credits:
+ *	Saeed Karamooz <saeed@ramix.com> of Ramix INC. for the
+ *	initial example code of how to initialize this device and for
+ *	help with questions I had concerning operation of the device.
+ *
+ *	Most of the MTD code for this driver was originally written
+ *	for the slram.o module in the MTD drivers package which
+ *	allows the mapping of system memory into an MTD device.
+ *	Since the PMC551 memory module is accessed in the same
+ *	fashion as system memory, the slram.c code became a very nice
+ *	fit to the needs of this driver.  All we added was PCI
+ *	detection/initialization to the driver and automatically figure
+ *	out the size via the PCI detection.o, later changes by Corey
+ *	Minyard set up the card to utilize a 1M sliding apature.
+ *
+ *	Corey Minyard <minyard@nortelnetworks.com>
+ *	* Modified driver to utilize a sliding aperture instead of
+ *	 mapping all memory into kernel space which turned out to
+ *	 be very wasteful.
+ *	* Located a bug in the SROM's initialization sequence that
+ *	 made the memory unusable, added a fix to code to touch up
+ *	 the DRAM some.
+ *
+ * Bugs/FIXMEs:
+ *	* MUST fix the init function to not spin on a register
+ *	waiting for it to set .. this does not safely handle busted
+ *	devices that never reset the register correctly which will
+ *	cause the system to hang w/ a reboot being the only chance at
+ *	recover. [sort of fixed, could be better]
+ *	* Add I2C handling of the SROM so we can read the SROM's information
+ *	about the aperture size.  This should always accurately reflect the
+ *	onboard memory size.
+ *	* Comb the init routine.  It's still a bit cludgy on a few things.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <asm/io.h>
+#include <linux/pci.h>
+#include <linux/mtd/mtd.h>
+
+#define PMC551_VERSION \
+	"Ramix PMC551 PCI Mezzanine Ram Driver. (C) 1999,2000 Nortel Networks.\n"
+
+#define PCI_VENDOR_ID_V3_SEMI 0x11b0
+#define PCI_DEVICE_ID_V3_SEMI_V370PDC 0x0200
+
+#define PMC551_PCI_MEM_MAP0 0x50
+#define PMC551_PCI_MEM_MAP1 0x54
+#define PMC551_PCI_MEM_MAP_MAP_ADDR_MASK 0x3ff00000
+#define PMC551_PCI_MEM_MAP_APERTURE_MASK 0x000000f0
+#define PMC551_PCI_MEM_MAP_REG_EN 0x00000002
+#define PMC551_PCI_MEM_MAP_ENABLE 0x00000001
+
+#define PMC551_SDRAM_MA  0x60
+#define PMC551_SDRAM_CMD 0x62
+#define PMC551_DRAM_CFG  0x64
+#define PMC551_SYS_CTRL_REG 0x78
+
+#define PMC551_DRAM_BLK0 0x68
+#define PMC551_DRAM_BLK1 0x6c
+#define PMC551_DRAM_BLK2 0x70
+#define PMC551_DRAM_BLK3 0x74
+#define PMC551_DRAM_BLK_GET_SIZE(x) (524288 << ((x >> 4) & 0x0f))
+#define PMC551_DRAM_BLK_SET_COL_MUX(x, v) (((x) & ~0x00007000) | (((v) & 0x7) << 12))
+#define PMC551_DRAM_BLK_SET_ROW_MUX(x, v) (((x) & ~0x00000f00) | (((v) & 0xf) << 8))
+
+struct mypriv {
+	struct pci_dev *dev;
+	u_char *start;
+	u32 base_map0;
+	u32 curr_map0;
+	u32 asize;
+	struct mtd_info *nextpmc551;
+};
+
+static struct mtd_info *pmc551list;
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys);
+
+static int pmc551_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	size_t retlen;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase(pos:%ld, len:%ld)\n", (long)instr->addr,
+		(long)instr->len);
+#endif
+
+	end = instr->addr + instr->len - 1;
+	eoff_hi = end & ~(priv->asize - 1);
+	soff_hi = instr->addr & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, instr->addr, instr->len, &retlen,
+		     (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi || mtd->size == priv->asize) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memset(ptr, 0xff, instr->len);
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_erase() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memset(ptr, 0xff, priv->asize);
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, (priv->base_map0 | soff_hi),
+				     priv->asize, &retlen,
+				     (void **)&ptr, NULL);
+		}
+		memset(ptr, 0xff, eoff_lo);
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase() done\n");
+#endif
+
+	return 0;
+}
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;
+	u32 soff_lo;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_point(%ld, %ld)\n", (long)from, (long)len);
+#endif
+
+	soff_hi = from & ~(priv->asize - 1);
+	soff_lo = from & (priv->asize - 1);
+
+	/* Cheap hack optimization */
+	if (priv->curr_map0 != from) {
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					(priv->base_map0 | soff_hi));
+		priv->curr_map0 = soff_hi;
+	}
+
+	*virt = priv->start + soff_lo;
+	*retlen = len;
+	return 0;
+}
+
+static int pmc551_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_unpoint()\n");
+#endif
+	return 0;
+}
+
+static int pmc551_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t * retlen, u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	u_char *copyto = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read(pos:%ld, len:%ld) asize: %ld\n",
+		(long)from, (long)len, (long)priv->asize);
+#endif
+
+	end = from + len - 1;
+	soff_hi = from & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, from, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(copyto, ptr, len);
+		copyto += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_read() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(copyto, ptr, priv->asize);
+			copyto += priv->asize;
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(copyto, ptr, eoff_lo);
+		copyto += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read() done\n");
+#endif
+	*retlen = copyto - buf;
+	return 0;
+}
+
+static int pmc551_write(struct mtd_info *mtd, loff_t to, size_t len,
+			size_t * retlen, const u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	const u_char *copyfrom = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write(pos:%ld, len:%ld) asize:%ld\n",
+		(long)to, (long)len, (long)priv->asize);
+#endif
+
+	end = to + len - 1;
+	soff_hi = to & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, to, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(ptr, copyfrom, len);
+		copyfrom += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_write() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(ptr, copyfrom, priv->asize);
+			copyfrom += priv->asize;
+			if (soff_hi >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(ptr, copyfrom, eoff_lo);
+		copyfrom += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write() done\n");
+#endif
+	*retlen = copyfrom - buf;
+	return 0;
+}
+
+/*
+ * Fixup routines for the V370PDC
+ * PCI device ID 0x020011b0
+ *
+ * This function basically kick starts the DRAM oboard the card and gets it
+ * ready to be used.  Before this is done the device reads VERY erratic, so
+ * much that it can crash the Linux 2.2.x series kernels when a user cat's
+ * /proc/pci .. though that is mainly a kernel bug in handling the PCI DEVSEL
+ * register.  FIXME: stop spinning on registers .. must implement a timeout
+ * mechanism
+ * returns the size of the memory region found.
+ */
+static int __init fixup_pmc551(struct pci_dev *dev)
+{
+#ifdef CONFIG_MTD_PMC551_BUGFIX
+	u32 dram_data;
+#endif
+	u32 size, dcmd, cfg, dtmp;
+	u16 cmd, tmp, i;
+	u8 bcmd, counter;
+
+	/* Sanity Check */
+	if (!dev) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Attempt to reset the card
+	 * FIXME: Stop Spinning registers
+	 */
+	counter = 0;
+	/* unlock registers */
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, 0xA5);
+	/* read in old data */
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	/* bang the reset line up and down for a few */
+	for (i = 0; i < 10; i++) {
+		counter = 0;
+		bcmd &= ~0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+		counter = 0;
+		bcmd |= 0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+	}
+	bcmd |= (0x40 | 0x20);
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+
+	/*
+	 * Take care and turn off the memory on the device while we
+	 * tweak the configurations
+	 */
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	tmp = cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+	pci_write_config_word(dev, PCI_COMMAND, tmp);
+
+	/*
+	 * Disable existing aperture before probing memory size
+	 */
+	pci_read_config_dword(dev, PMC551_PCI_MEM_MAP0, &dcmd);
+	dtmp = (dcmd | PMC551_PCI_MEM_MAP_ENABLE | PMC551_PCI_MEM_MAP_REG_EN);
+	pci_write_config_dword(dev, PMC551_PCI_MEM_MAP0, dtmp);
+	/*
+	 * Grab old BAR0 config so that we can figure out memory size
+	 * This is another bit of kludge going on.  The reason for the
+	 * redundancy is I am hoping to retain the original configuration
+	 * previously assigned to the card by the BIOS or some previous
+	 * fixup routine in the kernel.  So we read the old config into cfg,
+	 * then write all 1's to the memory space, read back the result into
+	 * "size", and then write back all the old config.
+	 */
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &cfg);
+#ifndef CONFIG_MTD_PMC551_BUGFIX
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, ~0);
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &size);
+	size = (size & PCI_BASE_ADDRESS_MEM_MASK);
+	size &= ~(size - 1);
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, cfg);
+#else
+	/*
+	 * Get the size of the memory by reading all the DRAM size values
+	 * and adding them up.
+	 *
+	 * KLUDGE ALERT: the boards we are using have invalid column and
+	 * row mux values.  We fix them here, but this will break other
+	 * memory configurations.
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dram_data);
+	size = PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK0, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK1, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK2, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK3, dram_data);
+
+	/*
+	 * Oops .. something went wrong
+	 */
+	if ((size &= PCI_BASE_ADDRESS_MEM_MASK) == 0) {
+		return -ENODEV;
+	}
+#endif				/* CONFIG_MTD_PMC551_BUGFIX */
+
+	if ((cfg & PCI_BASE_ADDRESS_SPACE) != PCI_BASE_ADDRESS_SPACE_MEMORY) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Precharge Dram
+	 */
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0400);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x00bf);
+
+	/*
+	 * Wait until command has gone through
+	 * FIXME: register spinning issue
+	 */
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	/*
+	 * Turn on auto refresh
+	 * The loop is taken directly from Ramix's example code.  I assume that
+	 * this must be held high for some duration of time, but I can find no
+	 * documentation refrencing the reasons why.
+	 */
+	for (i = 1; i <= 8; i++) {
+		pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0df);
+
+		/*
+		 * Make certain command has gone through
+		 * FIXME: register spinning issue
+		 */
+		counter = 0;
+		do {
+			pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+			if (counter++ > 100)
+				break;
+		} while ((PCI_COMMAND_IO) & cmd);
+	}
+
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0020);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0ff);
+
+	/*
+	 * Wait until command completes
+	 * FIXME: register spinning issue
+	 */
+	counter = 0;
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	pci_read_config_dword(dev, PMC551_DRAM_CFG, &dcmd);
+	dcmd |= 0x02000000;
+	pci_write_config_dword(dev, PMC551_DRAM_CFG, dcmd);
+
+	/*
+	 * Check to make certain fast back-to-back, if not
+	 * then set it so
+	 */
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	if ((cmd & PCI_COMMAND_FAST_BACK) == 0) {
+		cmd |= PCI_COMMAND_FAST_BACK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+
+	/*
+	 * Check to make certain the DEVSEL is set correctly, this device
+	 * has a tendency to assert DEVSEL and TRDY when a write is performed
+	 * to the memory when memory is read-only
+	 */
+	if ((cmd & PCI_STATUS_DEVSEL_MASK) != 0x0) {
+		cmd &= ~PCI_STATUS_DEVSEL_MASK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+	/*
+	 * Set to be prefetchable and put everything back based on old cfg.
+	 * it's possible that the reset of the V370PDC nuked the original
+	 * setup
+	 */
+	/*
+	   cfg |= PCI_BASE_ADDRESS_MEM_PREFETCH;
+	   pci_write_config_dword( dev, PCI_BASE_ADDRESS_0, cfg );
+	 */
+
+	/*
+	 * Turn PCI memory and I/O bus access back on
+	 */
+	pci_write_config_word(dev, PCI_COMMAND,
+			      PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	/*
+	 * Some screen fun
+	 */
+	printk(KERN_DEBUG "pmc551: %d%sB (0x%x) of %sprefetchable memory at "
+		"0x%llx\n", (size < 1024) ? size : (size < 1048576) ?
+		size >> 10 : size >> 20,
+		(size < 1024) ? "" : (size < 1048576) ? "Ki" : "Mi", size,
+		((dcmd & (0x1 << 3)) == 0) ? "non-" : "",
+		(unsigned long long)pci_resource_start(dev, 0));
+
+	/*
+	 * Check to see the state of the memory
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK0 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK0 Size: %d at %d\n"
+		"pmc551: DRAM_BLK0 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK1 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK1 Size: %d at %d\n"
+		"pmc551: DRAM_BLK1 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK2 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK2 Size: %d at %d\n"
+		"pmc551: DRAM_BLK2 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK3 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK3 Size: %d at %d\n"
+		"pmc551: DRAM_BLK3 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	printk(KERN_DEBUG "pmc551: Memory Access %s\n",
+		(((0x1 << 1) & cmd) == 0) ? "off" : "on");
+	printk(KERN_DEBUG "pmc551: I/O Access %s\n",
+		(((0x1 << 0) & cmd) == 0) ? "off" : "on");
+
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	printk(KERN_DEBUG "pmc551: Devsel %s\n",
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x000) ? "Fast" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x200) ? "Medium" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x400) ? "Slow" : "Invalid");
+
+	printk(KERN_DEBUG "pmc551: %sFast Back-to-Back\n",
+		((PCI_COMMAND_FAST_BACK & cmd) == 0) ? "Not " : "");
+
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	printk(KERN_DEBUG "pmc551: EEPROM is under %s control\n"
+		"pmc551: System Control Register is %slocked to PCI access\n"
+		"pmc551: System Control Register is %slocked to EEPROM access\n",
+		(bcmd & 0x1) ? "software" : "hardware",
+		(bcmd & 0x20) ? "" : "un", (bcmd & 0x40) ? "" : "un");
+#endif
+	return size;
+}
+
+/*
+ * Kernel version specific module stuffages
+ */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Ferrell <mferrell@mvista.com>");
+MODULE_DESCRIPTION(PMC551_VERSION);
+
+/*
+ * Stuff these outside the ifdef so as to not bust compiled in driver support
+ */
+static int msize = 0;
+static int asize = 0;
+
+module_param(msize, int, 0);
+MODULE_PARM_DESC(msize, "memory size in MiB [1 - 1024]");
+module_param(asize, int, 0);
+MODULE_PARM_DESC(asize, "aperture size, must be <= memsize [1-1024]");
+
+/*
+ * PMC551 Card Initialization
+ */
+static int __init init_pmc551(void)
+{
+	struct pci_dev *PCI_Device = NULL;
+	struct mypriv *priv;
+	int found = 0;
+	struct mtd_info *mtd;
+	int length = 0;
+
+	if (msize) {
+		msize = (1 << (ffs(msize) - 1)) << 20;
+		if (msize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid memory size [%d]\n",
+				msize);
+			return -EINVAL;
+		}
+	}
+
+	if (asize) {
+		asize = (1 << (ffs(asize) - 1)) << 20;
+		if (asize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid aperture size "
+				"[%d]\n", asize);
+			return -EINVAL;
+		}
+	}
+
+	printk(KERN_INFO PMC551_VERSION);
+
+	/*
+	 * PCU-bus chipset probe.
+	 */
+	for (;;) {
+
+		if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
+						  PCI_DEVICE_ID_V3_SEMI_V370PDC,
+						  PCI_Device)) == NULL) {
+			break;
+		}
+
+		printk(KERN_NOTICE "pmc551: Found PCI V370PDC at 0x%llx\n",
+			(unsigned long long)pci_resource_start(PCI_Device, 0));
+
+		/*
+		 * The PMC551 device acts VERY weird if you don't init it
+		 * first.  i.e. it will not correctly report devsel.  If for
+		 * some reason the sdram is in a wrote-protected state the
+		 * device will DEVSEL when it is written to causing problems
+		 * with the oldproc.c driver in
+		 * some kernels (2.2.*)
+		 */
+		if ((length = fixup_pmc551(PCI_Device)) <= 0) {
+			printk(KERN_NOTICE "pmc551: Cannot init SDRAM\n");
+			break;
+		}
+
+		/*
+		 * This is needed until the driver is capable of reading the
+		 * onboard I2C SROM to discover the "real" memory size.
+		 */
+		if (msize) {
+			length = msize;
+			printk(KERN_NOTICE "pmc551: Using specified memory "
+				"size 0x%x\n", length);
+		} else {
+			msize = length;
+		}
+
+		mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+		if (!mtd)
+			break;
+
+		priv = kzalloc(sizeof(struct mypriv), GFP_KERNEL);
+		if (!priv) {
+			kfree(mtd);
+			break;
+		}
+		mtd->priv = priv;
+		priv->dev = PCI_Device;
+
+		if (asize > length) {
+			printk(KERN_NOTICE "pmc551: reducing aperture size to "
+				"fit %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else if (asize == 0 || asize == length) {
+			printk(KERN_NOTICE "pmc551: Using existing aperture "
+				"size %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else {
+			printk(KERN_NOTICE "pmc551: Using specified aperture "
+				"size %dM\n", asize >> 20);
+			priv->asize = asize;
+		}
+		priv->start = pci_iomap(PCI_Device, 0, priv->asize);
+
+		if (!priv->start) {
+			printk(KERN_NOTICE "pmc551: Unable to map IO space\n");
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: setting aperture to %d\n",
+			ffs(priv->asize >> 20) - 1);
+#endif
+
+		priv->base_map0 = (PMC551_PCI_MEM_MAP_REG_EN
+				   | PMC551_PCI_MEM_MAP_ENABLE
+				   | (ffs(priv->asize >> 20) - 1) << 4);
+		priv->curr_map0 = priv->base_map0;
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					priv->curr_map0);
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: aperture set to %d\n",
+			(priv->base_map0 & 0xF0) >> 4);
+#endif
+
+		mtd->size = msize;
+		mtd->flags = MTD_CAP_RAM;
+		mtd->_erase = pmc551_erase;
+		mtd->_read = pmc551_read;
+		mtd->_write = pmc551_write;
+		mtd->_point = pmc551_point;
+		mtd->_unpoint = pmc551_unpoint;
+		mtd->type = MTD_RAM;
+		mtd->name = "PMC551 RAM board";
+		mtd->erasesize = 0x10000;
+		mtd->writesize = 1;
+		mtd->owner = THIS_MODULE;
+
+		if (mtd_device_register(mtd, NULL, 0)) {
+			printk(KERN_NOTICE "pmc551: Failed to register new device\n");
+			pci_iounmap(PCI_Device, priv->start);
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+
+		/* Keep a reference as the mtd_device_register worked */
+		pci_dev_get(PCI_Device);
+
+		printk(KERN_NOTICE "Registered pmc551 memory device.\n");
+		printk(KERN_NOTICE "Mapped %dMiB of memory from 0x%p to 0x%p\n",
+			priv->asize >> 20,
+			priv->start, priv->start + priv->asize);
+		printk(KERN_NOTICE "Total memory is %d%sB\n",
+			(length < 1024) ? length :
+			(length < 1048576) ? length >> 10 : length >> 20,
+			(length < 1024) ? "" : (length < 1048576) ? "Ki" : "Mi");
+		priv->nextpmc551 = pmc551list;
+		pmc551list = mtd;
+		found++;
+	}
+
+	/* Exited early, reference left over */
+	pci_dev_put(PCI_Device);
+
+	if (!pmc551list) {
+		printk(KERN_NOTICE "pmc551: not detected\n");
+		return -ENODEV;
+	} else {
+		printk(KERN_NOTICE "pmc551: %d pmc551 devices loaded\n", found);
+		return 0;
+	}
+}
+
+/*
+ * PMC551 Card Cleanup
+ */
+static void __exit cleanup_pmc551(void)
+{
+	int found = 0;
+	struct mtd_info *mtd;
+	struct mypriv *priv;
+
+	while ((mtd = pmc551list)) {
+		priv = mtd->priv;
+		pmc551list = priv->nextpmc551;
+
+		if (priv->start) {
+			printk(KERN_DEBUG "pmc551: unmapping %dMiB starting at "
+				"0x%p\n", priv->asize >> 20, priv->start);
+			pci_iounmap(priv->dev, priv->start);
+		}
+		pci_dev_put(priv->dev);
+
+		kfree(mtd->priv);
+		mtd_device_unregister(mtd);
+		kfree(mtd);
+		found++;
+	}
+
+	printk(KERN_NOTICE "pmc551: %d pmc551 devices unloaded\n", found);
+}
+
+module_init(init_pmc551);
+module_exit(cleanup_pmc551);