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, 982 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
new file mode 100644
index 000000000..f9d059647
--- /dev/null
+++ b/drivers/acpi/acpica/nsxfeval.c
@@ -0,0 +1,982 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*******************************************************************************
+ *
+ * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
+ *                         ACPI Object evaluation interfaces
+ *
+ ******************************************************************************/
+
+#define EXPORT_ACPI_INTERFACES
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acnamesp.h"
+#include "acinterp.h"
+
+#define _COMPONENT          ACPI_NAMESPACE
+ACPI_MODULE_NAME("nsxfeval")
+
+/* Local prototypes */
+static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_evaluate_object_typed
+ *
+ * PARAMETERS:  handle              - Object handle (optional)
+ *              pathname            - Object pathname (optional)
+ *              external_params     - List of parameters to pass to a method,
+ *                                    terminated by NULL. May be NULL
+ *                                    if no parameters are being passed.
+ *              return_buffer       - Where to put the object's return value (if
+ *                                    any). If NULL, no value is returned.
+ *              return_type         - Expected type of return object
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Find and evaluate the given object, passing the given
+ *              parameters if necessary. One of "Handle" or "Pathname" must
+ *              be valid (non-null)
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_evaluate_object_typed(acpi_handle handle,
+			   acpi_string pathname,
+			   struct acpi_object_list *external_params,
+			   struct acpi_buffer *return_buffer,
+			   acpi_object_type return_type)
+{
+	acpi_status status;
+	u8 free_buffer_on_error = FALSE;
+	acpi_handle target_handle;
+	char *full_pathname;
+
+	ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
+
+	/* Return buffer must be valid */
+
+	if (!return_buffer) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
+		free_buffer_on_error = TRUE;
+	}
+
+	/* Get a handle here, in order to build an error message if needed */
+
+	target_handle = handle;
+	if (pathname) {
+		status = acpi_get_handle(handle, pathname, &target_handle);
+		if (ACPI_FAILURE(status)) {
+			return_ACPI_STATUS(status);
+		}
+	}
+
+	full_pathname = acpi_ns_get_external_pathname(target_handle);
+	if (!full_pathname) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	/* Evaluate the object */
+
+	status = acpi_evaluate_object(target_handle, NULL, external_params,
+				      return_buffer);
+	if (ACPI_FAILURE(status)) {
+		goto exit;
+	}
+
+	/* Type ANY means "don't care about return value type" */
+
+	if (return_type == ACPI_TYPE_ANY) {
+		goto exit;
+	}
+
+	if (return_buffer->length == 0) {
+
+		/* Error because caller specifically asked for a return value */
+
+		ACPI_ERROR((AE_INFO, "%s did not return any object",
+			    full_pathname));
+		status = AE_NULL_OBJECT;
+		goto exit;
+	}
+
+	/* Examine the object type returned from evaluate_object */
+
+	if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
+		goto exit;
+	}
+
+	/* Return object type does not match requested type */
+
+	ACPI_ERROR((AE_INFO,
+		    "Incorrect return type from %s - received [%s], requested [%s]",
+		    full_pathname,
+		    acpi_ut_get_type_name(((union acpi_object *)return_buffer->
+					   pointer)->type),
+		    acpi_ut_get_type_name(return_type)));
+
+	if (free_buffer_on_error) {
+		/*
+		 * Free a buffer created via ACPI_ALLOCATE_BUFFER.
+		 * Note: We use acpi_os_free here because acpi_os_allocate was used
+		 * to allocate the buffer. This purposefully bypasses the
+		 * (optionally enabled) allocation tracking mechanism since we
+		 * only want to track internal allocations.
+		 */
+		acpi_os_free(return_buffer->pointer);
+		return_buffer->pointer = NULL;
+	}
+
+	return_buffer->length = 0;
+	status = AE_TYPE;
+
+exit:
+	ACPI_FREE(full_pathname);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_evaluate_object
+ *
+ * PARAMETERS:  handle              - Object handle (optional)
+ *              pathname            - Object pathname (optional)
+ *              external_params     - List of parameters to pass to method,
+ *                                    terminated by NULL. May be NULL
+ *                                    if no parameters are being passed.
+ *              return_buffer       - Where to put method's return value (if
+ *                                    any). If NULL, no value is returned.
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Find and evaluate the given object, passing the given
+ *              parameters if necessary. One of "Handle" or "Pathname" must
+ *              be valid (non-null)
+ *
+ ******************************************************************************/
+acpi_status
+acpi_evaluate_object(acpi_handle handle,
+		     acpi_string pathname,
+		     struct acpi_object_list *external_params,
+		     struct acpi_buffer *return_buffer)
+{
+	acpi_status status;
+	struct acpi_evaluate_info *info;
+	acpi_size buffer_space_needed;
+	u32 i;
+
+	ACPI_FUNCTION_TRACE(acpi_evaluate_object);
+
+	/* Allocate and initialize the evaluation information block */
+
+	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
+	if (!info) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	/* Convert and validate the device handle */
+
+	info->prefix_node = acpi_ns_validate_handle(handle);
+	if (!info->prefix_node) {
+		status = AE_BAD_PARAMETER;
+		goto cleanup;
+	}
+
+	/*
+	 * Get the actual namespace node for the target object.
+	 * Handles these cases:
+	 *
+	 * 1) Null node, valid pathname from root (absolute path)
+	 * 2) Node and valid pathname (path relative to Node)
+	 * 3) Node, Null pathname
+	 */
+	if ((pathname) && (ACPI_IS_ROOT_PREFIX(pathname[0]))) {
+
+		/* The path is fully qualified, just evaluate by name */
+
+		info->prefix_node = NULL;
+	} else if (!handle) {
+		/*
+		 * A handle is optional iff a fully qualified pathname is specified.
+		 * Since we've already handled fully qualified names above, this is
+		 * an error.
+		 */
+		if (!pathname) {
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					  "Both Handle and Pathname are NULL"));
+		} else {
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					  "Null Handle with relative pathname [%s]",
+					  pathname));
+		}
+
+		status = AE_BAD_PARAMETER;
+		goto cleanup;
+	}
+
+	info->relative_pathname = pathname;
+
+	/*
+	 * Convert all external objects passed as arguments to the
+	 * internal version(s).
+	 */
+	if (external_params && external_params->count) {
+		info->param_count = (u16)external_params->count;
+
+		/* Warn on impossible argument count */
+
+		if (info->param_count > ACPI_METHOD_NUM_ARGS) {
+			ACPI_WARN_PREDEFINED((AE_INFO, pathname,
+					      ACPI_WARN_ALWAYS,
+					      "Excess arguments (%u) - using only %u",
+					      info->param_count,
+					      ACPI_METHOD_NUM_ARGS));
+
+			info->param_count = ACPI_METHOD_NUM_ARGS;
+		}
+
+		/*
+		 * Allocate a new parameter block for the internal objects
+		 * Add 1 to count to allow for null terminated internal list
+		 */
+		info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)info->
+							 param_count +
+							 1) * sizeof(void *));
+		if (!info->parameters) {
+			status = AE_NO_MEMORY;
+			goto cleanup;
+		}
+
+		/* Convert each external object in the list to an internal object */
+
+		for (i = 0; i < info->param_count; i++) {
+			status =
+			    acpi_ut_copy_eobject_to_iobject(&external_params->
+							    pointer[i],
+							    &info->
+							    parameters[i]);
+			if (ACPI_FAILURE(status)) {
+				goto cleanup;
+			}
+		}
+
+		info->parameters[info->param_count] = NULL;
+	}
+
+#ifdef _FUTURE_FEATURE
+
+	/*
+	 * Begin incoming argument count analysis. Check for too few args
+	 * and too many args.
+	 */
+	switch (acpi_ns_get_type(info->node)) {
+	case ACPI_TYPE_METHOD:
+
+		/* Check incoming argument count against the method definition */
+
+		if (info->obj_desc->method.param_count > info->param_count) {
+			ACPI_ERROR((AE_INFO,
+				    "Insufficient arguments (%u) - %u are required",
+				    info->param_count,
+				    info->obj_desc->method.param_count));
+
+			status = AE_MISSING_ARGUMENTS;
+			goto cleanup;
+		}
+
+		else if (info->obj_desc->method.param_count < info->param_count) {
+			ACPI_WARNING((AE_INFO,
+				      "Excess arguments (%u) - only %u are required",
+				      info->param_count,
+				      info->obj_desc->method.param_count));
+
+			/* Just pass the required number of arguments */
+
+			info->param_count = info->obj_desc->method.param_count;
+		}
+
+		/*
+		 * Any incoming external objects to be passed as arguments to the
+		 * method must be converted to internal objects
+		 */
+		if (info->param_count) {
+			/*
+			 * Allocate a new parameter block for the internal objects
+			 * Add 1 to count to allow for null terminated internal list
+			 */
+			info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
+								 info->
+								 param_count +
+								 1) *
+								sizeof(void *));
+			if (!info->parameters) {
+				status = AE_NO_MEMORY;
+				goto cleanup;
+			}
+
+			/* Convert each external object in the list to an internal object */
+
+			for (i = 0; i < info->param_count; i++) {
+				status =
+				    acpi_ut_copy_eobject_to_iobject
+				    (&external_params->pointer[i],
+				     &info->parameters[i]);
+				if (ACPI_FAILURE(status)) {
+					goto cleanup;
+				}
+			}
+
+			info->parameters[info->param_count] = NULL;
+		}
+		break;
+
+	default:
+
+		/* Warn if arguments passed to an object that is not a method */
+
+		if (info->param_count) {
+			ACPI_WARNING((AE_INFO,
+				      "%u arguments were passed to a non-method ACPI object",
+				      info->param_count));
+		}
+		break;
+	}
+
+#endif
+
+	/* Now we can evaluate the object */
+
+	status = acpi_ns_evaluate(info);
+
+	/*
+	 * If we are expecting a return value, and all went well above,
+	 * copy the return value to an external object.
+	 */
+	if (!return_buffer) {
+		goto cleanup_return_object;
+	}
+
+	if (!info->return_object) {
+		return_buffer->length = 0;
+		goto cleanup;
+	}
+
+	if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
+	    ACPI_DESC_TYPE_NAMED) {
+		/*
+		 * If we received a NS Node as a return object, this means that
+		 * the object we are evaluating has nothing interesting to
+		 * return (such as a mutex, etc.)  We return an error because
+		 * these types are essentially unsupported by this interface.
+		 * We don't check up front because this makes it easier to add
+		 * support for various types at a later date if necessary.
+		 */
+		status = AE_TYPE;
+		info->return_object = NULL;	/* No need to delete a NS Node */
+		return_buffer->length = 0;
+	}
+
+	if (ACPI_FAILURE(status)) {
+		goto cleanup_return_object;
+	}
+
+	/* Dereference Index and ref_of references */
+
+	acpi_ns_resolve_references(info);
+
+	/* Get the size of the returned object */
+
+	status = acpi_ut_get_object_size(info->return_object,
+					 &buffer_space_needed);
+	if (ACPI_SUCCESS(status)) {
+
+		/* Validate/Allocate/Clear caller buffer */
+
+		status = acpi_ut_initialize_buffer(return_buffer,
+						   buffer_space_needed);
+		if (ACPI_FAILURE(status)) {
+			/*
+			 * Caller's buffer is too small or a new one can't
+			 * be allocated
+			 */
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					  "Needed buffer size %X, %s\n",
+					  (u32)buffer_space_needed,
+					  acpi_format_exception(status)));
+		} else {
+			/* We have enough space for the object, build it */
+
+			status =
+			    acpi_ut_copy_iobject_to_eobject(info->return_object,
+							    return_buffer);
+		}
+	}
+
+cleanup_return_object:
+
+	if (info->return_object) {
+		/*
+		 * Delete the internal return object. NOTE: Interpreter must be
+		 * locked to avoid race condition.
+		 */
+		acpi_ex_enter_interpreter();
+
+		/* Remove one reference on the return object (should delete it) */
+
+		acpi_ut_remove_reference(info->return_object);
+		acpi_ex_exit_interpreter();
+	}
+
+cleanup:
+
+	/* Free the input parameter list (if we created one) */
+
+	if (info->parameters) {
+
+		/* Free the allocated parameter block */
+
+		acpi_ut_delete_internal_object_list(info->parameters);
+	}
+
+	ACPI_FREE(info);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_resolve_references
+ *
+ * PARAMETERS:  info                    - Evaluation info block
+ *
+ * RETURN:      Info->return_object is replaced with the dereferenced object
+ *
+ * DESCRIPTION: Dereference certain reference objects. Called before an
+ *              internal return object is converted to an external union acpi_object.
+ *
+ * Performs an automatic dereference of Index and ref_of reference objects.
+ * These reference objects are not supported by the union acpi_object, so this is a
+ * last resort effort to return something useful. Also, provides compatibility
+ * with other ACPI implementations.
+ *
+ * NOTE: does not handle references within returned package objects or nested
+ * references, but this support could be added later if found to be necessary.
+ *
+ ******************************************************************************/
+static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
+{
+	union acpi_operand_object *obj_desc = NULL;
+	struct acpi_namespace_node *node;
+
+	/* We are interested in reference objects only */
+
+	if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
+		return;
+	}
+
+	/*
+	 * Two types of references are supported - those created by Index and
+	 * ref_of operators. A name reference (AML_NAMEPATH_OP) can be converted
+	 * to a union acpi_object, so it is not dereferenced here. A ddb_handle
+	 * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
+	 * a union acpi_object.
+	 */
+	switch (info->return_object->reference.class) {
+	case ACPI_REFCLASS_INDEX:
+
+		obj_desc = *(info->return_object->reference.where);
+		break;
+
+	case ACPI_REFCLASS_REFOF:
+
+		node = info->return_object->reference.object;
+		if (node) {
+			obj_desc = node->object;
+		}
+		break;
+
+	default:
+
+		return;
+	}
+
+	/* Replace the existing reference object */
+
+	if (obj_desc) {
+		acpi_ut_add_reference(obj_desc);
+		acpi_ut_remove_reference(info->return_object);
+		info->return_object = obj_desc;
+	}
+
+	return;
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_walk_namespace
+ *
+ * PARAMETERS:  type                - acpi_object_type to search for
+ *              start_object        - Handle in namespace where search begins
+ *              max_depth           - Depth to which search is to reach
+ *              descending_callback - Called during tree descent
+ *                                    when an object of "Type" is found
+ *              ascending_callback  - Called during tree ascent
+ *                                    when an object of "Type" is found
+ *              context             - Passed to user function(s) above
+ *              return_value        - Location where return value of
+ *                                    user_function is put if terminated early
+ *
+ * RETURNS      Return value from the user_function if terminated early.
+ *              Otherwise, returns NULL.
+ *
+ * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
+ *              starting (and ending) at the object specified by start_handle.
+ *              The callback function is called whenever an object that matches
+ *              the type parameter is found. If the callback function returns
+ *              a non-zero value, the search is terminated immediately and this
+ *              value is returned to the caller.
+ *
+ *              The point of this procedure is to provide a generic namespace
+ *              walk routine that can be called from multiple places to
+ *              provide multiple services; the callback function(s) can be
+ *              tailored to each task, whether it is a print function,
+ *              a compare function, etc.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_walk_namespace(acpi_object_type type,
+		    acpi_handle start_object,
+		    u32 max_depth,
+		    acpi_walk_callback descending_callback,
+		    acpi_walk_callback ascending_callback,
+		    void *context, void **return_value)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_walk_namespace);
+
+	/* Parameter validation */
+
+	if ((type > ACPI_TYPE_LOCAL_MAX) ||
+	    (!max_depth) || (!descending_callback && !ascending_callback)) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	/*
+	 * Need to acquire the namespace reader lock to prevent interference
+	 * with any concurrent table unloads (which causes the deletion of
+	 * namespace objects). We cannot allow the deletion of a namespace node
+	 * while the user function is using it. The exception to this are the
+	 * nodes created and deleted during control method execution -- these
+	 * nodes are marked as temporary nodes and are ignored by the namespace
+	 * walk. Thus, control methods can be executed while holding the
+	 * namespace deletion lock (and the user function can execute control
+	 * methods.)
+	 */
+	status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/*
+	 * Lock the namespace around the walk. The namespace will be
+	 * unlocked/locked around each call to the user function - since the user
+	 * function must be allowed to make ACPICA calls itself (for example, it
+	 * will typically execute control methods during device enumeration.)
+	 */
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		goto unlock_and_exit;
+	}
+
+	/* Now we can validate the starting node */
+
+	if (!acpi_ns_validate_handle(start_object)) {
+		status = AE_BAD_PARAMETER;
+		goto unlock_and_exit2;
+	}
+
+	status = acpi_ns_walk_namespace(type, start_object, max_depth,
+					ACPI_NS_WALK_UNLOCK,
+					descending_callback, ascending_callback,
+					context, return_value);
+
+unlock_and_exit2:
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+unlock_and_exit:
+	(void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ns_get_device_callback
+ *
+ * PARAMETERS:  Callback from acpi_get_device
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
+ *              present devices, or if they specified a HID, it filters based
+ *              on that.
+ *
+ ******************************************************************************/
+static acpi_status
+acpi_ns_get_device_callback(acpi_handle obj_handle,
+			    u32 nesting_level,
+			    void *context, void **return_value)
+{
+	struct acpi_get_devices_info *info = context;
+	acpi_status status;
+	struct acpi_namespace_node *node;
+	u32 flags;
+	struct acpi_pnp_device_id *hid;
+	struct acpi_pnp_device_id_list *cid;
+	u32 i;
+	u8 found;
+	int no_match;
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	node = acpi_ns_validate_handle(obj_handle);
+	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	if (!node) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	/*
+	 * First, filter based on the device HID and CID.
+	 *
+	 * 01/2010: For this case where a specific HID is requested, we don't
+	 * want to run _STA until we have an actual HID match. Thus, we will
+	 * not unnecessarily execute _STA on devices for which the caller
+	 * doesn't care about. Previously, _STA was executed unconditionally
+	 * on all devices found here.
+	 *
+	 * A side-effect of this change is that now we will continue to search
+	 * for a matching HID even under device trees where the parent device
+	 * would have returned a _STA that indicates it is not present or
+	 * not functioning (thus aborting the search on that branch).
+	 */
+	if (info->hid != NULL) {
+		status = acpi_ut_execute_HID(node, &hid);
+		if (status == AE_NOT_FOUND) {
+			return (AE_OK);
+		} else if (ACPI_FAILURE(status)) {
+			return (AE_CTRL_DEPTH);
+		}
+
+		no_match = strcmp(hid->string, info->hid);
+		ACPI_FREE(hid);
+
+		if (no_match) {
+			/*
+			 * HID does not match, attempt match within the
+			 * list of Compatible IDs (CIDs)
+			 */
+			status = acpi_ut_execute_CID(node, &cid);
+			if (status == AE_NOT_FOUND) {
+				return (AE_OK);
+			} else if (ACPI_FAILURE(status)) {
+				return (AE_CTRL_DEPTH);
+			}
+
+			/* Walk the CID list */
+
+			found = FALSE;
+			for (i = 0; i < cid->count; i++) {
+				if (strcmp(cid->ids[i].string, info->hid) == 0) {
+
+					/* Found a matching CID */
+
+					found = TRUE;
+					break;
+				}
+			}
+
+			ACPI_FREE(cid);
+			if (!found) {
+				return (AE_OK);
+			}
+		}
+	}
+
+	/* Run _STA to determine if device is present */
+
+	status = acpi_ut_execute_STA(node, &flags);
+	if (ACPI_FAILURE(status)) {
+		return (AE_CTRL_DEPTH);
+	}
+
+	if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
+	    !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
+		/*
+		 * Don't examine the children of the device only when the
+		 * device is neither present nor functional. See ACPI spec,
+		 * description of _STA for more information.
+		 */
+		return (AE_CTRL_DEPTH);
+	}
+
+	/* We have a valid device, invoke the user function */
+
+	status = info->user_function(obj_handle, nesting_level,
+				     info->context, return_value);
+	return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_get_devices
+ *
+ * PARAMETERS:  HID                 - HID to search for. Can be NULL.
+ *              user_function       - Called when a matching object is found
+ *              context             - Passed to user function
+ *              return_value        - Location where return value of
+ *                                    user_function is put if terminated early
+ *
+ * RETURNS      Return value from the user_function if terminated early.
+ *              Otherwise, returns NULL.
+ *
+ * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
+ *              starting (and ending) at the object specified by start_handle.
+ *              The user_function is called whenever an object of type
+ *              Device is found. If the user function returns
+ *              a non-zero value, the search is terminated immediately and this
+ *              value is returned to the caller.
+ *
+ *              This is a wrapper for walk_namespace, but the callback performs
+ *              additional filtering. Please see acpi_ns_get_device_callback.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_get_devices(const char *HID,
+		 acpi_walk_callback user_function,
+		 void *context, void **return_value)
+{
+	acpi_status status;
+	struct acpi_get_devices_info info;
+
+	ACPI_FUNCTION_TRACE(acpi_get_devices);
+
+	/* Parameter validation */
+
+	if (!user_function) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	/*
+	 * We're going to call their callback from OUR callback, so we need
+	 * to know what it is, and their context parameter.
+	 */
+	info.hid = HID;
+	info.context = context;
+	info.user_function = user_function;
+
+	/*
+	 * Lock the namespace around the walk.
+	 * The namespace will be unlocked/locked around each call
+	 * to the user function - since this function
+	 * must be allowed to make Acpi calls itself.
+	 */
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+					ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
+					acpi_ns_get_device_callback, NULL,
+					&info, return_value);
+
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_devices)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_attach_data
+ *
+ * PARAMETERS:  obj_handle          - Namespace node
+ *              handler             - Handler for this attachment
+ *              data                - Pointer to data to be attached
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_attach_data(acpi_handle obj_handle,
+		 acpi_object_handler handler, void *data)
+{
+	struct acpi_namespace_node *node;
+	acpi_status status;
+
+	/* Parameter validation */
+
+	if (!obj_handle || !handler || !data) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	/* Convert and validate the handle */
+
+	node = acpi_ns_validate_handle(obj_handle);
+	if (!node) {
+		status = AE_BAD_PARAMETER;
+		goto unlock_and_exit;
+	}
+
+	status = acpi_ns_attach_data(node, handler, data);
+
+unlock_and_exit:
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return (status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_attach_data)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_detach_data
+ *
+ * PARAMETERS:  obj_handle          - Namespace node handle
+ *              handler             - Handler used in call to acpi_attach_data
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Remove data that was previously attached to a node.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
+{
+	struct acpi_namespace_node *node;
+	acpi_status status;
+
+	/* Parameter validation */
+
+	if (!obj_handle || !handler) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	/* Convert and validate the handle */
+
+	node = acpi_ns_validate_handle(obj_handle);
+	if (!node) {
+		status = AE_BAD_PARAMETER;
+		goto unlock_and_exit;
+	}
+
+	status = acpi_ns_detach_data(node, handler);
+
+unlock_and_exit:
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return (status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_detach_data)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_get_data_full
+ *
+ * PARAMETERS:  obj_handle          - Namespace node
+ *              handler             - Handler used in call to attach_data
+ *              data                - Where the data is returned
+ *              callback            - function to execute before returning
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Retrieve data that was previously attached to a namespace node
+ *              and execute a callback before returning.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_get_data_full(acpi_handle obj_handle, acpi_object_handler handler,
+		   void **data, void (*callback)(void *))
+{
+	struct acpi_namespace_node *node;
+	acpi_status status;
+
+	/* Parameter validation */
+
+	if (!obj_handle || !handler || !data) {
+		return (AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return (status);
+	}
+
+	/* Convert and validate the handle */
+
+	node = acpi_ns_validate_handle(obj_handle);
+	if (!node) {
+		status = AE_BAD_PARAMETER;
+		goto unlock_and_exit;
+	}
+
+	status = acpi_ns_get_attached_data(node, handler, data);
+	if (ACPI_SUCCESS(status) && callback) {
+		callback(*data);
+	}
+
+unlock_and_exit:
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return (status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_data_full)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_get_data
+ *
+ * PARAMETERS:  obj_handle          - Namespace node
+ *              handler             - Handler used in call to attach_data
+ *              data                - Where the data is returned
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
+{
+	return acpi_get_data_full(obj_handle, handler, data, NULL);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_data)