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, 535 insertions, 0 deletions

diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
new file mode 100644
index 000000000..7bde7fb64
--- /dev/null
+++ b/sound/core/pcm_memory.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/io.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/info.h>
+#include <sound/initval.h>
+#include "pcm_local.h"
+
+static int preallocate_dma = 1;
+module_param(preallocate_dma, int, 0444);
+MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
+
+static int maximum_substreams = 4;
+module_param(maximum_substreams, int, 0444);
+MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
+
+static const size_t snd_minimum_buffer = 16384;
+
+static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL;
+module_param(max_alloc_per_card, ulong, 0644);
+MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card.");
+
+static int do_alloc_pages(struct snd_card *card, int type, struct device *dev,
+			  int str, size_t size, struct snd_dma_buffer *dmab)
+{
+	enum dma_data_direction dir;
+	int err;
+
+	if (max_alloc_per_card &&
+	    card->total_pcm_alloc_bytes + size > max_alloc_per_card)
+		return -ENOMEM;
+
+	if (str == SNDRV_PCM_STREAM_PLAYBACK)
+		dir = DMA_TO_DEVICE;
+	else
+		dir = DMA_FROM_DEVICE;
+	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
+	if (!err) {
+		mutex_lock(&card->memory_mutex);
+		card->total_pcm_alloc_bytes += dmab->bytes;
+		mutex_unlock(&card->memory_mutex);
+	}
+	return err;
+}
+
+static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab)
+{
+	if (!dmab->area)
+		return;
+	mutex_lock(&card->memory_mutex);
+	WARN_ON(card->total_pcm_alloc_bytes < dmab->bytes);
+	card->total_pcm_alloc_bytes -= dmab->bytes;
+	mutex_unlock(&card->memory_mutex);
+	snd_dma_free_pages(dmab);
+	dmab->area = NULL;
+}
+
+/*
+ * try to allocate as the large pages as possible.
+ * stores the resultant memory size in *res_size.
+ *
+ * the minimum size is snd_minimum_buffer.  it should be power of 2.
+ */
+static int preallocate_pcm_pages(struct snd_pcm_substream *substream,
+				 size_t size, bool no_fallback)
+{
+	struct snd_dma_buffer *dmab = &substream->dma_buffer;
+	struct snd_card *card = substream->pcm->card;
+	size_t orig_size = size;
+	int err;
+
+	do {
+		err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev,
+				     substream->stream, size, dmab);
+		if (err != -ENOMEM)
+			return err;
+		if (no_fallback)
+			break;
+		size >>= 1;
+	} while (size >= snd_minimum_buffer);
+	dmab->bytes = 0; /* tell error */
+	pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+		substream->pcm->card->number, substream->pcm->device,
+		substream->stream ? 'c' : 'p', substream->number,
+		substream->pcm->name, orig_size);
+	return -ENOMEM;
+}
+
+/**
+ * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
+ * @substream: the pcm substream instance
+ *
+ * Releases the pre-allocated buffer of the given substream.
+ */
+void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
+{
+	do_free_pages(substream->pcm->card, &substream->dma_buffer);
+}
+
+/**
+ * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
+ * @pcm: the pcm instance
+ *
+ * Releases all the pre-allocated buffers on the given pcm.
+ */
+void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	int stream;
+
+	for_each_pcm_substream(pcm, stream, substream)
+		snd_pcm_lib_preallocate_free(substream);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+/*
+ * read callback for prealloc proc file
+ *
+ * prints the current allocated size in kB.
+ */
+static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
+					      struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
+}
+
+/*
+ * read callback for prealloc_max proc file
+ *
+ * prints the maximum allowed size in kB.
+ */
+static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
+						  struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
+}
+
+/*
+ * write callback for prealloc proc file
+ *
+ * accepts the preallocation size in kB.
+ */
+static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
+					       struct snd_info_buffer *buffer)
+{
+	struct snd_pcm_substream *substream = entry->private_data;
+	struct snd_card *card = substream->pcm->card;
+	char line[64], str[64];
+	size_t size;
+	struct snd_dma_buffer new_dmab;
+
+	mutex_lock(&substream->pcm->open_mutex);
+	if (substream->runtime) {
+		buffer->error = -EBUSY;
+		goto unlock;
+	}
+	if (!snd_info_get_line(buffer, line, sizeof(line))) {
+		snd_info_get_str(str, line, sizeof(str));
+		size = simple_strtoul(str, NULL, 10) * 1024;
+		if ((size != 0 && size < 8192) || size > substream->dma_max) {
+			buffer->error = -EINVAL;
+			goto unlock;
+		}
+		if (substream->dma_buffer.bytes == size)
+			goto unlock;
+		memset(&new_dmab, 0, sizeof(new_dmab));
+		new_dmab.dev = substream->dma_buffer.dev;
+		if (size > 0) {
+			if (do_alloc_pages(card,
+					   substream->dma_buffer.dev.type,
+					   substream->dma_buffer.dev.dev,
+					   substream->stream,
+					   size, &new_dmab) < 0) {
+				buffer->error = -ENOMEM;
+				pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+					 substream->pcm->card->number, substream->pcm->device,
+					 substream->stream ? 'c' : 'p', substream->number,
+					 substream->pcm->name, size);
+				goto unlock;
+			}
+			substream->buffer_bytes_max = size;
+		} else {
+			substream->buffer_bytes_max = UINT_MAX;
+		}
+		if (substream->dma_buffer.area)
+			do_free_pages(card, &substream->dma_buffer);
+		substream->dma_buffer = new_dmab;
+	} else {
+		buffer->error = -EINVAL;
+	}
+ unlock:
+	mutex_unlock(&substream->pcm->open_mutex);
+}
+
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
+					   substream->proc_root);
+	if (entry) {
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_proc_read);
+		entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
+		entry->mode |= 0200;
+	}
+	entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
+					   substream->proc_root);
+	if (entry)
+		snd_info_set_text_ops(entry, substream,
+				      snd_pcm_lib_preallocate_max_proc_read);
+}
+
+#else /* !CONFIG_SND_VERBOSE_PROCFS */
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+}
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
+
+/*
+ * pre-allocate the buffer and create a proc file for the substream
+ */
+static int preallocate_pages(struct snd_pcm_substream *substream,
+			      int type, struct device *data,
+			      size_t size, size_t max, bool managed)
+{
+	int err;
+
+	if (snd_BUG_ON(substream->dma_buffer.dev.type))
+		return -EINVAL;
+
+	substream->dma_buffer.dev.type = type;
+	substream->dma_buffer.dev.dev = data;
+
+	if (size > 0) {
+		if (!max) {
+			/* no fallback, only also inform -ENOMEM */
+			err = preallocate_pcm_pages(substream, size, true);
+			if (err < 0)
+				return err;
+		} else if (preallocate_dma &&
+			   substream->number < maximum_substreams) {
+			err = preallocate_pcm_pages(substream, size, false);
+			if (err < 0 && err != -ENOMEM)
+				return err;
+		}
+	}
+
+	if (substream->dma_buffer.bytes > 0)
+		substream->buffer_bytes_max = substream->dma_buffer.bytes;
+	substream->dma_max = max;
+	if (max > 0)
+		preallocate_info_init(substream);
+	if (managed)
+		substream->managed_buffer_alloc = 1;
+	return 0;
+}
+
+static int preallocate_pages_for_all(struct snd_pcm *pcm, int type,
+				      void *data, size_t size, size_t max,
+				      bool managed)
+{
+	struct snd_pcm_substream *substream;
+	int stream, err;
+
+	for_each_pcm_substream(pcm, stream, substream) {
+		err = preallocate_pages(substream, type, data, size, max, managed);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+/**
+ * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
+ * @substream: the pcm substream instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation for the given DMA buffer type.
+ */
+void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
+				  int type, struct device *data,
+				  size_t size, size_t max)
+{
+	preallocate_pages(substream, type, data, size, max, false);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
+
+/**
+ * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
+ * @pcm: the pcm instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation to all substreams of the given pcm for the
+ * specified DMA type.
+ */
+void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
+					  int type, void *data,
+					  size_t size, size_t max)
+{
+	preallocate_pages_for_all(pcm, type, data, size, max, false);
+}
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
+
+/**
+ * snd_pcm_set_managed_buffer - set up buffer management for a substream
+ * @substream: the pcm substream instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation for the given DMA buffer type, and set the managed
+ * buffer allocation mode to the given substream.
+ * In this mode, PCM core will allocate a buffer automatically before PCM
+ * hw_params ops call, and release the buffer after PCM hw_free ops call
+ * as well, so that the driver doesn't need to invoke the allocation and
+ * the release explicitly in its callback.
+ * When a buffer is actually allocated before the PCM hw_params call, it
+ * turns on the runtime buffer_changed flag for drivers changing their h/w
+ * parameters accordingly.
+ *
+ * When @size is non-zero and @max is zero, this tries to allocate for only
+ * the exact buffer size without fallback, and may return -ENOMEM.
+ * Otherwise, the function tries to allocate smaller chunks if the allocation
+ * fails.  This is the behavior of snd_pcm_set_fixed_buffer().
+ *
+ * When both @size and @max are zero, the function only sets up the buffer
+ * for later dynamic allocations. It's used typically for buffers with
+ * SNDRV_DMA_TYPE_VMALLOC type.
+ *
+ * Upon successful buffer allocation and setup, the function returns 0.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type,
+				struct device *data, size_t size, size_t max)
+{
+	return preallocate_pages(substream, type, data, size, max, true);
+}
+EXPORT_SYMBOL(snd_pcm_set_managed_buffer);
+
+/**
+ * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams
+ *	for all substreams
+ * @pcm: the pcm instance
+ * @type: DMA type (SNDRV_DMA_TYPE_*)
+ * @data: DMA type dependent data
+ * @size: the requested pre-allocation size in bytes
+ * @max: the max. allowed pre-allocation size
+ *
+ * Do pre-allocation to all substreams of the given pcm for the specified DMA
+ * type and size, and set the managed_buffer_alloc flag to each substream.
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type,
+				   struct device *data,
+				   size_t size, size_t max)
+{
+	return preallocate_pages_for_all(pcm, type, data, size, max, true);
+}
+EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all);
+
+/**
+ * snd_pcm_lib_malloc_pages - allocate the DMA buffer
+ * @substream: the substream to allocate the DMA buffer to
+ * @size: the requested buffer size in bytes
+ *
+ * Allocates the DMA buffer on the BUS type given earlier to
+ * snd_pcm_lib_preallocate_xxx_pages().
+ *
+ * Return: 1 if the buffer is changed, 0 if not changed, or a negative
+ * code on failure.
+ */
+int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
+{
+	struct snd_card *card;
+	struct snd_pcm_runtime *runtime;
+	struct snd_dma_buffer *dmab = NULL;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	if (snd_BUG_ON(substream->dma_buffer.dev.type ==
+		       SNDRV_DMA_TYPE_UNKNOWN))
+		return -EINVAL;
+	runtime = substream->runtime;
+	card = substream->pcm->card;
+
+	if (runtime->dma_buffer_p) {
+		/* perphaps, we might free the large DMA memory region
+		   to save some space here, but the actual solution
+		   costs us less time */
+		if (runtime->dma_buffer_p->bytes >= size) {
+			runtime->dma_bytes = size;
+			return 0;	/* ok, do not change */
+		}
+		snd_pcm_lib_free_pages(substream);
+	}
+	if (substream->dma_buffer.area != NULL &&
+	    substream->dma_buffer.bytes >= size) {
+		dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
+	} else {
+		/* dma_max=0 means the fixed size preallocation */
+		if (substream->dma_buffer.area && !substream->dma_max)
+			return -ENOMEM;
+		dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
+		if (! dmab)
+			return -ENOMEM;
+		dmab->dev = substream->dma_buffer.dev;
+		if (do_alloc_pages(card,
+				   substream->dma_buffer.dev.type,
+				   substream->dma_buffer.dev.dev,
+				   substream->stream,
+				   size, dmab) < 0) {
+			kfree(dmab);
+			pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
+				 substream->pcm->card->number, substream->pcm->device,
+				 substream->stream ? 'c' : 'p', substream->number,
+				 substream->pcm->name, size);
+			return -ENOMEM;
+		}
+	}
+	snd_pcm_set_runtime_buffer(substream, dmab);
+	runtime->dma_bytes = size;
+	return 1;			/* area was changed */
+}
+EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
+
+/**
+ * snd_pcm_lib_free_pages - release the allocated DMA buffer.
+ * @substream: the substream to release the DMA buffer
+ *
+ * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	if (runtime->dma_area == NULL)
+		return 0;
+	if (runtime->dma_buffer_p != &substream->dma_buffer) {
+		struct snd_card *card = substream->pcm->card;
+
+		/* it's a newly allocated buffer.  release it now. */
+		do_free_pages(card, runtime->dma_buffer_p);
+		kfree(runtime->dma_buffer_p);
+	}
+	snd_pcm_set_runtime_buffer(substream, NULL);
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_lib_free_pages);
+
+int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
+				      size_t size, gfp_t gfp_flags)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	if (runtime->dma_area) {
+		if (runtime->dma_bytes >= size)
+			return 0; /* already large enough */
+		vfree(runtime->dma_area);
+	}
+	runtime->dma_area = __vmalloc(size, gfp_flags);
+	if (!runtime->dma_area)
+		return -ENOMEM;
+	runtime->dma_bytes = size;
+	return 1;
+}
+EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
+
+/**
+ * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
+ * @substream: the substream with a buffer allocated by
+ *	snd_pcm_lib_alloc_vmalloc_buffer()
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime;
+
+	if (PCM_RUNTIME_CHECK(substream))
+		return -EINVAL;
+	runtime = substream->runtime;
+	vfree(runtime->dma_area);
+	runtime->dma_area = NULL;
+	return 0;
+}
+EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
+
+/**
+ * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
+ * @substream: the substream with a buffer allocated by
+ *	snd_pcm_lib_alloc_vmalloc_buffer()
+ * @offset: offset in the buffer
+ *
+ * This function is to be used as the page callback in the PCM ops.
+ *
+ * Return: The page struct, or %NULL on failure.
+ */
+struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
+					  unsigned long offset)
+{
+	return vmalloc_to_page(substream->runtime->dma_area + offset);
+}
+EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);