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, 657 insertions, 0 deletions

diff --git a/drivers/dma/mediatek/mtk-uart-apdma.c b/drivers/dma/mediatek/mtk-uart-apdma.c
new file mode 100644
index 000000000..a1517ef1f
--- /dev/null
+++ b/drivers/dma/mediatek/mtk-uart-apdma.c
@@ -0,0 +1,657 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek UART APDMA driver.
+ *
+ * Copyright (c) 2019 MediaTek Inc.
+ * Author: Long Cheng <long.cheng@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "../virt-dma.h"
+
+/* The default number of virtual channel */
+#define MTK_UART_APDMA_NR_VCHANS	8
+
+#define VFF_EN_B		BIT(0)
+#define VFF_STOP_B		BIT(0)
+#define VFF_FLUSH_B		BIT(0)
+#define VFF_4G_EN_B		BIT(0)
+/* rx valid size >=  vff thre */
+#define VFF_RX_INT_EN_B		(BIT(0) | BIT(1))
+/* tx left size >= vff thre */
+#define VFF_TX_INT_EN_B		BIT(0)
+#define VFF_WARM_RST_B		BIT(0)
+#define VFF_RX_INT_CLR_B	(BIT(0) | BIT(1))
+#define VFF_TX_INT_CLR_B	0
+#define VFF_STOP_CLR_B		0
+#define VFF_EN_CLR_B		0
+#define VFF_INT_EN_CLR_B	0
+#define VFF_4G_SUPPORT_CLR_B	0
+
+/*
+ * interrupt trigger level for tx
+ * if threshold is n, no polling is required to start tx.
+ * otherwise need polling VFF_FLUSH.
+ */
+#define VFF_TX_THRE(n)		(n)
+/* interrupt trigger level for rx */
+#define VFF_RX_THRE(n)		((n) * 3 / 4)
+
+#define VFF_RING_SIZE	0xffff
+/* invert this bit when wrap ring head again */
+#define VFF_RING_WRAP	0x10000
+
+#define VFF_INT_FLAG		0x00
+#define VFF_INT_EN		0x04
+#define VFF_EN			0x08
+#define VFF_RST			0x0c
+#define VFF_STOP		0x10
+#define VFF_FLUSH		0x14
+#define VFF_ADDR		0x1c
+#define VFF_LEN			0x24
+#define VFF_THRE		0x28
+#define VFF_WPT			0x2c
+#define VFF_RPT			0x30
+/* TX: the buffer size HW can read. RX: the buffer size SW can read. */
+#define VFF_VALID_SIZE		0x3c
+/* TX: the buffer size SW can write. RX: the buffer size HW can write. */
+#define VFF_LEFT_SIZE		0x40
+#define VFF_DEBUG_STATUS	0x50
+#define VFF_4G_SUPPORT		0x54
+
+struct mtk_uart_apdmadev {
+	struct dma_device ddev;
+	struct clk *clk;
+	bool support_33bits;
+	unsigned int dma_requests;
+};
+
+struct mtk_uart_apdma_desc {
+	struct virt_dma_desc vd;
+
+	dma_addr_t addr;
+	unsigned int avail_len;
+};
+
+struct mtk_chan {
+	struct virt_dma_chan vc;
+	struct dma_slave_config	cfg;
+	struct mtk_uart_apdma_desc *desc;
+	enum dma_transfer_direction dir;
+
+	void __iomem *base;
+	unsigned int irq;
+
+	unsigned int rx_status;
+};
+
+static inline struct mtk_uart_apdmadev *
+to_mtk_uart_apdma_dev(struct dma_device *d)
+{
+	return container_of(d, struct mtk_uart_apdmadev, ddev);
+}
+
+static inline struct mtk_chan *to_mtk_uart_apdma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct mtk_chan, vc.chan);
+}
+
+static inline struct mtk_uart_apdma_desc *to_mtk_uart_apdma_desc
+	(struct dma_async_tx_descriptor *t)
+{
+	return container_of(t, struct mtk_uart_apdma_desc, vd.tx);
+}
+
+static void mtk_uart_apdma_write(struct mtk_chan *c,
+			       unsigned int reg, unsigned int val)
+{
+	writel(val, c->base + reg);
+}
+
+static unsigned int mtk_uart_apdma_read(struct mtk_chan *c, unsigned int reg)
+{
+	return readl(c->base + reg);
+}
+
+static void mtk_uart_apdma_desc_free(struct virt_dma_desc *vd)
+{
+	kfree(container_of(vd, struct mtk_uart_apdma_desc, vd));
+}
+
+static void mtk_uart_apdma_start_tx(struct mtk_chan *c)
+{
+	struct mtk_uart_apdmadev *mtkd =
+				to_mtk_uart_apdma_dev(c->vc.chan.device);
+	struct mtk_uart_apdma_desc *d = c->desc;
+	unsigned int wpt, vff_sz;
+
+	vff_sz = c->cfg.dst_port_window_size;
+	if (!mtk_uart_apdma_read(c, VFF_LEN)) {
+		mtk_uart_apdma_write(c, VFF_ADDR, d->addr);
+		mtk_uart_apdma_write(c, VFF_LEN, vff_sz);
+		mtk_uart_apdma_write(c, VFF_THRE, VFF_TX_THRE(vff_sz));
+		mtk_uart_apdma_write(c, VFF_WPT, 0);
+		mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_TX_INT_CLR_B);
+
+		if (mtkd->support_33bits)
+			mtk_uart_apdma_write(c, VFF_4G_SUPPORT, VFF_4G_EN_B);
+	}
+
+	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_B);
+	if (mtk_uart_apdma_read(c, VFF_EN) != VFF_EN_B)
+		dev_err(c->vc.chan.device->dev, "Enable TX fail\n");
+
+	if (!mtk_uart_apdma_read(c, VFF_LEFT_SIZE)) {
+		mtk_uart_apdma_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+		return;
+	}
+
+	wpt = mtk_uart_apdma_read(c, VFF_WPT);
+
+	wpt += c->desc->avail_len;
+	if ((wpt & VFF_RING_SIZE) == vff_sz)
+		wpt = (wpt & VFF_RING_WRAP) ^ VFF_RING_WRAP;
+
+	/* Let DMA start moving data */
+	mtk_uart_apdma_write(c, VFF_WPT, wpt);
+
+	/* HW auto set to 0 when left size >= threshold */
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+	if (!mtk_uart_apdma_read(c, VFF_FLUSH))
+		mtk_uart_apdma_write(c, VFF_FLUSH, VFF_FLUSH_B);
+}
+
+static void mtk_uart_apdma_start_rx(struct mtk_chan *c)
+{
+	struct mtk_uart_apdmadev *mtkd =
+				to_mtk_uart_apdma_dev(c->vc.chan.device);
+	struct mtk_uart_apdma_desc *d = c->desc;
+	unsigned int vff_sz;
+
+	vff_sz = c->cfg.src_port_window_size;
+	if (!mtk_uart_apdma_read(c, VFF_LEN)) {
+		mtk_uart_apdma_write(c, VFF_ADDR, d->addr);
+		mtk_uart_apdma_write(c, VFF_LEN, vff_sz);
+		mtk_uart_apdma_write(c, VFF_THRE, VFF_RX_THRE(vff_sz));
+		mtk_uart_apdma_write(c, VFF_RPT, 0);
+		mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_RX_INT_CLR_B);
+
+		if (mtkd->support_33bits)
+			mtk_uart_apdma_write(c, VFF_4G_SUPPORT, VFF_4G_EN_B);
+	}
+
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_RX_INT_EN_B);
+	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_B);
+	if (mtk_uart_apdma_read(c, VFF_EN) != VFF_EN_B)
+		dev_err(c->vc.chan.device->dev, "Enable RX fail\n");
+}
+
+static void mtk_uart_apdma_tx_handler(struct mtk_chan *c)
+{
+	mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_TX_INT_CLR_B);
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_CLR_B);
+}
+
+static void mtk_uart_apdma_rx_handler(struct mtk_chan *c)
+{
+	struct mtk_uart_apdma_desc *d = c->desc;
+	unsigned int len, wg, rg;
+	int cnt;
+
+	mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_RX_INT_CLR_B);
+
+	if (!mtk_uart_apdma_read(c, VFF_VALID_SIZE))
+		return;
+
+	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_CLR_B);
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+
+	len = c->cfg.src_port_window_size;
+	rg = mtk_uart_apdma_read(c, VFF_RPT);
+	wg = mtk_uart_apdma_read(c, VFF_WPT);
+	cnt = (wg & VFF_RING_SIZE) - (rg & VFF_RING_SIZE);
+
+	/*
+	 * The buffer is ring buffer. If wrap bit different,
+	 * represents the start of the next cycle for WPT
+	 */
+	if ((rg ^ wg) & VFF_RING_WRAP)
+		cnt += len;
+
+	c->rx_status = d->avail_len - cnt;
+	mtk_uart_apdma_write(c, VFF_RPT, wg);
+}
+
+static void mtk_uart_apdma_chan_complete_handler(struct mtk_chan *c)
+{
+	struct mtk_uart_apdma_desc *d = c->desc;
+
+	if (d) {
+		list_del(&d->vd.node);
+		vchan_cookie_complete(&d->vd);
+		c->desc = NULL;
+	}
+}
+
+static irqreturn_t mtk_uart_apdma_irq_handler(int irq, void *dev_id)
+{
+	struct dma_chan *chan = (struct dma_chan *)dev_id;
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	if (c->dir == DMA_DEV_TO_MEM)
+		mtk_uart_apdma_rx_handler(c);
+	else if (c->dir == DMA_MEM_TO_DEV)
+		mtk_uart_apdma_tx_handler(c);
+	mtk_uart_apdma_chan_complete_handler(c);
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static int mtk_uart_apdma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct mtk_uart_apdmadev *mtkd = to_mtk_uart_apdma_dev(chan->device);
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	unsigned int status;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(mtkd->ddev.dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(chan->device->dev);
+		return ret;
+	}
+
+	mtk_uart_apdma_write(c, VFF_ADDR, 0);
+	mtk_uart_apdma_write(c, VFF_THRE, 0);
+	mtk_uart_apdma_write(c, VFF_LEN, 0);
+	mtk_uart_apdma_write(c, VFF_RST, VFF_WARM_RST_B);
+
+	ret = readx_poll_timeout(readl, c->base + VFF_EN,
+			  status, !status, 10, 100);
+	if (ret)
+		goto err_pm;
+
+	ret = request_irq(c->irq, mtk_uart_apdma_irq_handler,
+			  IRQF_TRIGGER_NONE, KBUILD_MODNAME, chan);
+	if (ret < 0) {
+		dev_err(chan->device->dev, "Can't request dma IRQ\n");
+		ret = -EINVAL;
+		goto err_pm;
+	}
+
+	if (mtkd->support_33bits)
+		mtk_uart_apdma_write(c, VFF_4G_SUPPORT, VFF_4G_SUPPORT_CLR_B);
+
+err_pm:
+	pm_runtime_put_noidle(mtkd->ddev.dev);
+	return ret;
+}
+
+static void mtk_uart_apdma_free_chan_resources(struct dma_chan *chan)
+{
+	struct mtk_uart_apdmadev *mtkd = to_mtk_uart_apdma_dev(chan->device);
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+
+	free_irq(c->irq, chan);
+
+	tasklet_kill(&c->vc.task);
+
+	vchan_free_chan_resources(&c->vc);
+
+	pm_runtime_put_sync(mtkd->ddev.dev);
+}
+
+static enum dma_status mtk_uart_apdma_tx_status(struct dma_chan *chan,
+					 dma_cookie_t cookie,
+					 struct dma_tx_state *txstate)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	enum dma_status ret;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (!txstate)
+		return ret;
+
+	dma_set_residue(txstate, c->rx_status);
+
+	return ret;
+}
+
+/*
+ * dmaengine_prep_slave_single will call the function. and sglen is 1.
+ * 8250 uart using one ring buffer, and deal with one sg.
+ */
+static struct dma_async_tx_descriptor *mtk_uart_apdma_prep_slave_sg
+	(struct dma_chan *chan, struct scatterlist *sgl,
+	unsigned int sglen, enum dma_transfer_direction dir,
+	unsigned long tx_flags, void *context)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	struct mtk_uart_apdma_desc *d;
+
+	if (!is_slave_direction(dir) || sglen != 1)
+		return NULL;
+
+	/* Now allocate and setup the descriptor */
+	d = kzalloc(sizeof(*d), GFP_NOWAIT);
+	if (!d)
+		return NULL;
+
+	d->avail_len = sg_dma_len(sgl);
+	d->addr = sg_dma_address(sgl);
+	c->dir = dir;
+
+	return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
+}
+
+static void mtk_uart_apdma_issue_pending(struct dma_chan *chan)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	struct virt_dma_desc *vd;
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	if (vchan_issue_pending(&c->vc) && !c->desc) {
+		vd = vchan_next_desc(&c->vc);
+		c->desc = to_mtk_uart_apdma_desc(&vd->tx);
+
+		if (c->dir == DMA_DEV_TO_MEM)
+			mtk_uart_apdma_start_rx(c);
+		else if (c->dir == DMA_MEM_TO_DEV)
+			mtk_uart_apdma_start_tx(c);
+	}
+
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+}
+
+static int mtk_uart_apdma_slave_config(struct dma_chan *chan,
+				   struct dma_slave_config *config)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+
+	memcpy(&c->cfg, config, sizeof(*config));
+
+	return 0;
+}
+
+static int mtk_uart_apdma_terminate_all(struct dma_chan *chan)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	unsigned long flags;
+	unsigned int status;
+	LIST_HEAD(head);
+	int ret;
+
+	mtk_uart_apdma_write(c, VFF_FLUSH, VFF_FLUSH_B);
+
+	ret = readx_poll_timeout(readl, c->base + VFF_FLUSH,
+			  status, status != VFF_FLUSH_B, 10, 100);
+	if (ret)
+		dev_err(c->vc.chan.device->dev, "flush: fail, status=0x%x\n",
+			mtk_uart_apdma_read(c, VFF_DEBUG_STATUS));
+
+	/*
+	 * Stop need 3 steps.
+	 * 1. set stop to 1
+	 * 2. wait en to 0
+	 * 3. set stop as 0
+	 */
+	mtk_uart_apdma_write(c, VFF_STOP, VFF_STOP_B);
+	ret = readx_poll_timeout(readl, c->base + VFF_EN,
+			  status, !status, 10, 100);
+	if (ret)
+		dev_err(c->vc.chan.device->dev, "stop: fail, status=0x%x\n",
+			mtk_uart_apdma_read(c, VFF_DEBUG_STATUS));
+
+	mtk_uart_apdma_write(c, VFF_STOP, VFF_STOP_CLR_B);
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+
+	if (c->dir == DMA_DEV_TO_MEM)
+		mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_RX_INT_CLR_B);
+	else if (c->dir == DMA_MEM_TO_DEV)
+		mtk_uart_apdma_write(c, VFF_INT_FLAG, VFF_TX_INT_CLR_B);
+
+	synchronize_irq(c->irq);
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+	vchan_get_all_descriptors(&c->vc, &head);
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+
+	vchan_dma_desc_free_list(&c->vc, &head);
+
+	return 0;
+}
+
+static int mtk_uart_apdma_device_pause(struct dma_chan *chan)
+{
+	struct mtk_chan *c = to_mtk_uart_apdma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&c->vc.lock, flags);
+
+	mtk_uart_apdma_write(c, VFF_EN, VFF_EN_CLR_B);
+	mtk_uart_apdma_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+
+	synchronize_irq(c->irq);
+
+	spin_unlock_irqrestore(&c->vc.lock, flags);
+
+	return 0;
+}
+
+static void mtk_uart_apdma_free(struct mtk_uart_apdmadev *mtkd)
+{
+	while (!list_empty(&mtkd->ddev.channels)) {
+		struct mtk_chan *c = list_first_entry(&mtkd->ddev.channels,
+			struct mtk_chan, vc.chan.device_node);
+
+		list_del(&c->vc.chan.device_node);
+		tasklet_kill(&c->vc.task);
+	}
+}
+
+static const struct of_device_id mtk_uart_apdma_match[] = {
+	{ .compatible = "mediatek,mt6577-uart-dma", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mtk_uart_apdma_match);
+
+static int mtk_uart_apdma_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mtk_uart_apdmadev *mtkd;
+	int bit_mask = 32, rc;
+	struct mtk_chan *c;
+	unsigned int i;
+
+	mtkd = devm_kzalloc(&pdev->dev, sizeof(*mtkd), GFP_KERNEL);
+	if (!mtkd)
+		return -ENOMEM;
+
+	mtkd->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(mtkd->clk)) {
+		dev_err(&pdev->dev, "No clock specified\n");
+		rc = PTR_ERR(mtkd->clk);
+		return rc;
+	}
+
+	if (of_property_read_bool(np, "mediatek,dma-33bits"))
+		mtkd->support_33bits = true;
+
+	if (mtkd->support_33bits)
+		bit_mask = 33;
+
+	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(bit_mask));
+	if (rc)
+		return rc;
+
+	dma_cap_set(DMA_SLAVE, mtkd->ddev.cap_mask);
+	mtkd->ddev.device_alloc_chan_resources =
+				mtk_uart_apdma_alloc_chan_resources;
+	mtkd->ddev.device_free_chan_resources =
+				mtk_uart_apdma_free_chan_resources;
+	mtkd->ddev.device_tx_status = mtk_uart_apdma_tx_status;
+	mtkd->ddev.device_issue_pending = mtk_uart_apdma_issue_pending;
+	mtkd->ddev.device_prep_slave_sg = mtk_uart_apdma_prep_slave_sg;
+	mtkd->ddev.device_config = mtk_uart_apdma_slave_config;
+	mtkd->ddev.device_pause = mtk_uart_apdma_device_pause;
+	mtkd->ddev.device_terminate_all = mtk_uart_apdma_terminate_all;
+	mtkd->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+	mtkd->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+	mtkd->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	mtkd->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+	mtkd->ddev.dev = &pdev->dev;
+	INIT_LIST_HEAD(&mtkd->ddev.channels);
+
+	mtkd->dma_requests = MTK_UART_APDMA_NR_VCHANS;
+	if (of_property_read_u32(np, "dma-requests", &mtkd->dma_requests)) {
+		dev_info(&pdev->dev,
+			 "Using %u as missing dma-requests property\n",
+			 MTK_UART_APDMA_NR_VCHANS);
+	}
+
+	for (i = 0; i < mtkd->dma_requests; i++) {
+		c = devm_kzalloc(mtkd->ddev.dev, sizeof(*c), GFP_KERNEL);
+		if (!c) {
+			rc = -ENODEV;
+			goto err_no_dma;
+		}
+
+		c->base = devm_platform_ioremap_resource(pdev, i);
+		if (IS_ERR(c->base)) {
+			rc = PTR_ERR(c->base);
+			goto err_no_dma;
+		}
+		c->vc.desc_free = mtk_uart_apdma_desc_free;
+		vchan_init(&c->vc, &mtkd->ddev);
+
+		rc = platform_get_irq(pdev, i);
+		if (rc < 0)
+			goto err_no_dma;
+		c->irq = rc;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+
+	rc = dma_async_device_register(&mtkd->ddev);
+	if (rc)
+		goto rpm_disable;
+
+	platform_set_drvdata(pdev, mtkd);
+
+	/* Device-tree DMA controller registration */
+	rc = of_dma_controller_register(np, of_dma_xlate_by_chan_id, mtkd);
+	if (rc)
+		goto dma_remove;
+
+	return rc;
+
+dma_remove:
+	dma_async_device_unregister(&mtkd->ddev);
+rpm_disable:
+	pm_runtime_disable(&pdev->dev);
+err_no_dma:
+	mtk_uart_apdma_free(mtkd);
+	return rc;
+}
+
+static int mtk_uart_apdma_remove(struct platform_device *pdev)
+{
+	struct mtk_uart_apdmadev *mtkd = platform_get_drvdata(pdev);
+
+	of_dma_controller_free(pdev->dev.of_node);
+
+	mtk_uart_apdma_free(mtkd);
+
+	dma_async_device_unregister(&mtkd->ddev);
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_uart_apdma_suspend(struct device *dev)
+{
+	struct mtk_uart_apdmadev *mtkd = dev_get_drvdata(dev);
+
+	if (!pm_runtime_suspended(dev))
+		clk_disable_unprepare(mtkd->clk);
+
+	return 0;
+}
+
+static int mtk_uart_apdma_resume(struct device *dev)
+{
+	int ret;
+	struct mtk_uart_apdmadev *mtkd = dev_get_drvdata(dev);
+
+	if (!pm_runtime_suspended(dev)) {
+		ret = clk_prepare_enable(mtkd->clk);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM
+static int mtk_uart_apdma_runtime_suspend(struct device *dev)
+{
+	struct mtk_uart_apdmadev *mtkd = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(mtkd->clk);
+
+	return 0;
+}
+
+static int mtk_uart_apdma_runtime_resume(struct device *dev)
+{
+	struct mtk_uart_apdmadev *mtkd = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(mtkd->clk);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops mtk_uart_apdma_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(mtk_uart_apdma_suspend, mtk_uart_apdma_resume)
+	SET_RUNTIME_PM_OPS(mtk_uart_apdma_runtime_suspend,
+			   mtk_uart_apdma_runtime_resume, NULL)
+};
+
+static struct platform_driver mtk_uart_apdma_driver = {
+	.probe	= mtk_uart_apdma_probe,
+	.remove	= mtk_uart_apdma_remove,
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.pm		= &mtk_uart_apdma_pm_ops,
+		.of_match_table = of_match_ptr(mtk_uart_apdma_match),
+	},
+};
+
+module_platform_driver(mtk_uart_apdma_driver);
+
+MODULE_DESCRIPTION("MediaTek UART APDMA Controller Driver");
+MODULE_AUTHOR("Long Cheng <long.cheng@mediatek.com>");
+MODULE_LICENSE("GPL v2");