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, 450 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/eprom.c b/drivers/infiniband/hw/hfi1/eprom.c
new file mode 100644
index 000000000..fbe958107
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/eprom.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Copyright(c) 2015, 2016 Intel Corporation.
+ */
+
+#include <linux/delay.h>
+#include "hfi.h"
+#include "common.h"
+#include "eprom.h"
+
+/*
+ * The EPROM is logically divided into three partitions:
+ *	partition 0: the first 128K, visible from PCI ROM BAR
+ *	partition 1: 4K config file (sector size)
+ *	partition 2: the rest
+ */
+#define P0_SIZE (128 * 1024)
+#define P1_SIZE   (4 * 1024)
+#define P1_START P0_SIZE
+#define P2_START (P0_SIZE + P1_SIZE)
+
+/* controller page size, in bytes */
+#define EP_PAGE_SIZE 256
+#define EP_PAGE_MASK (EP_PAGE_SIZE - 1)
+#define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))
+
+/* controller commands */
+#define CMD_SHIFT 24
+#define CMD_NOP			    (0)
+#define CMD_READ_DATA(addr)	    ((0x03 << CMD_SHIFT) | addr)
+#define CMD_RELEASE_POWERDOWN_NOID  ((0xab << CMD_SHIFT))
+
+/* controller interface speeds */
+#define EP_SPEED_FULL 0x2	/* full speed */
+
+/*
+ * How long to wait for the EPROM to become available, in ms.
+ * The spec 32 Mb EPROM takes around 40s to erase then write.
+ * Double it for safety.
+ */
+#define EPROM_TIMEOUT 80000 /* ms */
+
+/*
+ * Read a 256 byte (64 dword) EPROM page.
+ * All callers have verified the offset is at a page boundary.
+ */
+static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
+{
+	int i;
+
+	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
+	for (i = 0; i < EP_PAGE_DWORDS; i++)
+		result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
+	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
+}
+
+/*
+ * Read length bytes starting at offset from the start of the EPROM.
+ */
+static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest)
+{
+	u32 buffer[EP_PAGE_DWORDS];
+	u32 end;
+	u32 start_offset;
+	u32 read_start;
+	u32 bytes;
+
+	if (len == 0)
+		return 0;
+
+	end = start + len;
+
+	/*
+	 * Make sure the read range is not outside of the controller read
+	 * command address range.  Note that '>' is correct below - the end
+	 * of the range is OK if it stops at the limit, but no higher.
+	 */
+	if (end > (1 << CMD_SHIFT))
+		return -EINVAL;
+
+	/* read the first partial page */
+	start_offset = start & EP_PAGE_MASK;
+	if (start_offset) {
+		/* partial starting page */
+
+		/* align and read the page that contains the start */
+		read_start = start & ~EP_PAGE_MASK;
+		read_page(dd, read_start, buffer);
+
+		/* the rest of the page is available data */
+		bytes = EP_PAGE_SIZE - start_offset;
+
+		if (len <= bytes) {
+			/* end is within this page */
+			memcpy(dest, (u8 *)buffer + start_offset, len);
+			return 0;
+		}
+
+		memcpy(dest, (u8 *)buffer + start_offset, bytes);
+
+		start += bytes;
+		len -= bytes;
+		dest += bytes;
+	}
+	/* start is now page aligned */
+
+	/* read whole pages */
+	while (len >= EP_PAGE_SIZE) {
+		read_page(dd, start, buffer);
+		memcpy(dest, buffer, EP_PAGE_SIZE);
+
+		start += EP_PAGE_SIZE;
+		len -= EP_PAGE_SIZE;
+		dest += EP_PAGE_SIZE;
+	}
+
+	/* read the last partial page */
+	if (len) {
+		read_page(dd, start, buffer);
+		memcpy(dest, buffer, len);
+	}
+
+	return 0;
+}
+
+/*
+ * Initialize the EPROM handler.
+ */
+int eprom_init(struct hfi1_devdata *dd)
+{
+	int ret = 0;
+
+	/* only the discrete chip has an EPROM */
+	if (dd->pcidev->device != PCI_DEVICE_ID_INTEL0)
+		return 0;
+
+	/*
+	 * It is OK if both HFIs reset the EPROM as long as they don't
+	 * do it at the same time.
+	 */
+	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
+	if (ret) {
+		dd_dev_err(dd,
+			   "%s: unable to acquire EPROM resource, no EPROM support\n",
+			   __func__);
+		goto done_asic;
+	}
+
+	/* reset EPROM to be sure it is in a good state */
+
+	/* set reset */
+	write_csr(dd, ASIC_EEP_CTL_STAT, ASIC_EEP_CTL_STAT_EP_RESET_SMASK);
+	/* clear reset, set speed */
+	write_csr(dd, ASIC_EEP_CTL_STAT,
+		  EP_SPEED_FULL << ASIC_EEP_CTL_STAT_RATE_SPI_SHIFT);
+
+	/* wake the device with command "release powerdown NoID" */
+	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_RELEASE_POWERDOWN_NOID);
+
+	dd->eprom_available = true;
+	release_chip_resource(dd, CR_EPROM);
+done_asic:
+	return ret;
+}
+
+/* magic character sequence that begins an image */
+#define IMAGE_START_MAGIC "APO="
+
+/* magic character sequence that might trail an image */
+#define IMAGE_TRAIL_MAGIC "egamiAPO"
+
+/* EPROM file types */
+#define HFI1_EFT_PLATFORM_CONFIG 2
+
+/* segment size - 128 KiB */
+#define SEG_SIZE (128 * 1024)
+
+struct hfi1_eprom_footer {
+	u32 oprom_size;		/* size of the oprom, in bytes */
+	u16 num_table_entries;
+	u16 version;		/* version of this footer */
+	u32 magic;		/* must be last */
+};
+
+struct hfi1_eprom_table_entry {
+	u32 type;		/* file type */
+	u32 offset;		/* file offset from start of EPROM */
+	u32 size;		/* file size, in bytes */
+};
+
+/*
+ * Calculate the max number of table entries that will fit within a directory
+ * buffer of size 'dir_size'.
+ */
+#define MAX_TABLE_ENTRIES(dir_size) \
+	(((dir_size) - sizeof(struct hfi1_eprom_footer)) / \
+		sizeof(struct hfi1_eprom_table_entry))
+
+#define DIRECTORY_SIZE(n) (sizeof(struct hfi1_eprom_footer) + \
+	(sizeof(struct hfi1_eprom_table_entry) * (n)))
+
+#define MAGIC4(a, b, c, d) ((d) << 24 | (c) << 16 | (b) << 8 | (a))
+#define FOOTER_MAGIC MAGIC4('e', 'p', 'r', 'm')
+#define FOOTER_VERSION 1
+
+/*
+ * Read all of partition 1.  The actual file is at the front.  Adjust
+ * the returned size if a trailing image magic is found.
+ */
+static int read_partition_platform_config(struct hfi1_devdata *dd, void **data,
+					  u32 *size)
+{
+	void *buffer;
+	void *p;
+	u32 length;
+	int ret;
+
+	buffer = kmalloc(P1_SIZE, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	ret = read_length(dd, P1_START, P1_SIZE, buffer);
+	if (ret) {
+		kfree(buffer);
+		return ret;
+	}
+
+	/* config partition is valid only if it starts with IMAGE_START_MAGIC */
+	if (memcmp(buffer, IMAGE_START_MAGIC, strlen(IMAGE_START_MAGIC))) {
+		kfree(buffer);
+		return -ENOENT;
+	}
+
+	/* scan for image magic that may trail the actual data */
+	p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
+	if (p)
+		length = p - buffer;
+	else
+		length = P1_SIZE;
+
+	*data = buffer;
+	*size = length;
+	return 0;
+}
+
+/*
+ * The segment magic has been checked.  There is a footer and table of
+ * contents present.
+ *
+ * directory is a u32 aligned buffer of size EP_PAGE_SIZE.
+ */
+static int read_segment_platform_config(struct hfi1_devdata *dd,
+					void *directory, void **data, u32 *size)
+{
+	struct hfi1_eprom_footer *footer;
+	struct hfi1_eprom_table_entry *table;
+	struct hfi1_eprom_table_entry *entry;
+	void *buffer = NULL;
+	void *table_buffer = NULL;
+	int ret, i;
+	u32 directory_size;
+	u32 seg_base, seg_offset;
+	u32 bytes_available, ncopied, to_copy;
+
+	/* the footer is at the end of the directory */
+	footer = (struct hfi1_eprom_footer *)
+			(directory + EP_PAGE_SIZE - sizeof(*footer));
+
+	/* make sure the structure version is supported */
+	if (footer->version != FOOTER_VERSION)
+		return -EINVAL;
+
+	/* oprom size cannot be larger than a segment */
+	if (footer->oprom_size >= SEG_SIZE)
+		return -EINVAL;
+
+	/* the file table must fit in a segment with the oprom */
+	if (footer->num_table_entries >
+			MAX_TABLE_ENTRIES(SEG_SIZE - footer->oprom_size))
+		return -EINVAL;
+
+	/* find the file table start, which precedes the footer */
+	directory_size = DIRECTORY_SIZE(footer->num_table_entries);
+	if (directory_size <= EP_PAGE_SIZE) {
+		/* the file table fits into the directory buffer handed in */
+		table = (struct hfi1_eprom_table_entry *)
+				(directory + EP_PAGE_SIZE - directory_size);
+	} else {
+		/* need to allocate and read more */
+		table_buffer = kmalloc(directory_size, GFP_KERNEL);
+		if (!table_buffer)
+			return -ENOMEM;
+		ret = read_length(dd, SEG_SIZE - directory_size,
+				  directory_size, table_buffer);
+		if (ret)
+			goto done;
+		table = table_buffer;
+	}
+
+	/* look for the platform configuration file in the table */
+	for (entry = NULL, i = 0; i < footer->num_table_entries; i++) {
+		if (table[i].type == HFI1_EFT_PLATFORM_CONFIG) {
+			entry = &table[i];
+			break;
+		}
+	}
+	if (!entry) {
+		ret = -ENOENT;
+		goto done;
+	}
+
+	/*
+	 * Sanity check on the configuration file size - it should never
+	 * be larger than 4 KiB.
+	 */
+	if (entry->size > (4 * 1024)) {
+		dd_dev_err(dd, "Bad configuration file size 0x%x\n",
+			   entry->size);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/* check for bogus offset and size that wrap when added together */
+	if (entry->offset + entry->size < entry->offset) {
+		dd_dev_err(dd,
+			   "Bad configuration file start + size 0x%x+0x%x\n",
+			   entry->offset, entry->size);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/* allocate the buffer to return */
+	buffer = kmalloc(entry->size, GFP_KERNEL);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	/*
+	 * Extract the file by looping over segments until it is fully read.
+	 */
+	seg_offset = entry->offset % SEG_SIZE;
+	seg_base = entry->offset - seg_offset;
+	ncopied = 0;
+	while (ncopied < entry->size) {
+		/* calculate data bytes available in this segment */
+
+		/* start with the bytes from the current offset to the end */
+		bytes_available = SEG_SIZE - seg_offset;
+		/* subtract off footer and table from segment 0 */
+		if (seg_base == 0) {
+			/*
+			 * Sanity check: should not have a starting point
+			 * at or within the directory.
+			 */
+			if (bytes_available <= directory_size) {
+				dd_dev_err(dd,
+					   "Bad configuration file - offset 0x%x within footer+table\n",
+					   entry->offset);
+				ret = -EINVAL;
+				goto done;
+			}
+			bytes_available -= directory_size;
+		}
+
+		/* calculate bytes wanted */
+		to_copy = entry->size - ncopied;
+
+		/* max out at the available bytes in this segment */
+		if (to_copy > bytes_available)
+			to_copy = bytes_available;
+
+		/*
+		 * Read from the EPROM.
+		 *
+		 * The sanity check for entry->offset is done in read_length().
+		 * The EPROM offset is validated against what the hardware
+		 * addressing supports.  In addition, if the offset is larger
+		 * than the actual EPROM, it silently wraps.  It will work
+		 * fine, though the reader may not get what they expected
+		 * from the EPROM.
+		 */
+		ret = read_length(dd, seg_base + seg_offset, to_copy,
+				  buffer + ncopied);
+		if (ret)
+			goto done;
+
+		ncopied += to_copy;
+
+		/* set up for next segment */
+		seg_offset = footer->oprom_size;
+		seg_base += SEG_SIZE;
+	}
+
+	/* success */
+	ret = 0;
+	*data = buffer;
+	*size = entry->size;
+
+done:
+	kfree(table_buffer);
+	if (ret)
+		kfree(buffer);
+	return ret;
+}
+
+/*
+ * Read the platform configuration file from the EPROM.
+ *
+ * On success, an allocated buffer containing the data and its size are
+ * returned.  It is up to the caller to free this buffer.
+ *
+ * Return value:
+ *   0	      - success
+ *   -ENXIO   - no EPROM is available
+ *   -EBUSY   - not able to acquire access to the EPROM
+ *   -ENOENT  - no recognizable file written
+ *   -ENOMEM  - buffer could not be allocated
+ *   -EINVAL  - invalid EPROM contentents found
+ */
+int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size)
+{
+	u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */
+	int ret;
+
+	if (!dd->eprom_available)
+		return -ENXIO;
+
+	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
+	if (ret)
+		return -EBUSY;
+
+	/* read the last page of the segment for the EPROM format magic */
+	ret = read_length(dd, SEG_SIZE - EP_PAGE_SIZE, EP_PAGE_SIZE, directory);
+	if (ret)
+		goto done;
+
+	/* last dword of the segment contains a magic value */
+	if (directory[EP_PAGE_DWORDS - 1] == FOOTER_MAGIC) {
+		/* segment format */
+		ret = read_segment_platform_config(dd, directory, data, size);
+	} else {
+		/* partition format */
+		ret = read_partition_platform_config(dd, data, size);
+	}
+
+done:
+	release_chip_resource(dd, CR_EPROM);
+	return ret;
+}