--- /dev/null
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smem.h>
+#include <linux/wait.h>
+#include <linux/rpmsg.h>
+
+#include "rpmsg_internal.h"
+
+/*
+ * The Qualcomm Shared Memory communication solution provides point-to-point
+ * channels for clients to send and receive streaming or packet based data.
+ *
+ * Each channel consists of a control item (channel info) and a ring buffer
+ * pair. The channel info carry information related to channel state, flow
+ * control and the offsets within the ring buffer.
+ *
+ * All allocated channels are listed in an allocation table, identifying the
+ * pair of items by name, type and remote processor.
+ *
+ * Upon creating a new channel the remote processor allocates channel info and
+ * ring buffer items from the smem heap and populate the allocation table. An
+ * interrupt is sent to the other end of the channel and a scan for new
+ * channels should be done. A channel never goes away, it will only change
+ * state.
+ *
+ * The remote processor signals it intent for bring up the communication
+ * channel by setting the state of its end of the channel to "opening" and
+ * sends out an interrupt. We detect this change and register a smd device to
+ * consume the channel. Upon finding a consumer we finish the handshake and the
+ * channel is up.
+ *
+ * Upon closing a channel, the remote processor will update the state of its
+ * end of the channel and signal us, we will then unregister any attached
+ * device and close our end of the channel.
+ *
+ * Devices attached to a channel can use the qcom_smd_send function to push
+ * data to the channel, this is done by copying the data into the tx ring
+ * buffer, updating the pointers in the channel info and signaling the remote
+ * processor.
+ *
+ * The remote processor does the equivalent when it transfer data and upon
+ * receiving the interrupt we check the channel info for new data and delivers
+ * this to the attached device. If the device is not ready to receive the data
+ * we leave it in the ring buffer for now.
+ */
+
+struct smd_channel_info;
+struct smd_channel_info_pair;
+struct smd_channel_info_word;
+struct smd_channel_info_word_pair;
+
+static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
+
+#define SMD_ALLOC_TBL_COUNT 2
+#define SMD_ALLOC_TBL_SIZE 64
+
+/*
+ * This lists the various smem heap items relevant for the allocation table and
+ * smd channel entries.
+ */
+static const struct {
+ unsigned alloc_tbl_id;
+ unsigned info_base_id;
+ unsigned fifo_base_id;
+} smem_items[SMD_ALLOC_TBL_COUNT] = {
+ {
+ .alloc_tbl_id = 13,
+ .info_base_id = 14,
+ .fifo_base_id = 338
+ },
+ {
+ .alloc_tbl_id = 266,
+ .info_base_id = 138,
+ .fifo_base_id = 202,
+ },
+};
+
+/**
+ * struct qcom_smd_edge - representing a remote processor
+ * @of_node: of_node handle for information related to this edge
+ * @edge_id: identifier of this edge
+ * @remote_pid: identifier of remote processor
+ * @irq: interrupt for signals on this edge
+ * @ipc_regmap: regmap handle holding the outgoing ipc register
+ * @ipc_offset: offset within @ipc_regmap of the register for ipc
+ * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
+ * @channels: list of all channels detected on this edge
+ * @channels_lock: guard for modifications of @channels
+ * @allocated: array of bitmaps representing already allocated channels
+ * @smem_available: last available amount of smem triggering a channel scan
+ * @scan_work: work item for discovering new channels
+ * @state_work: work item for edge state changes
+ */
+struct qcom_smd_edge {
+ struct device dev;
+
+ struct device_node *of_node;
+ unsigned edge_id;
+ unsigned remote_pid;
+
+ int irq;
+
+ struct regmap *ipc_regmap;
+ int ipc_offset;
+ int ipc_bit;
+
+ struct list_head channels;
+ spinlock_t channels_lock;
+
+ DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
+
+ unsigned smem_available;
+
+ wait_queue_head_t new_channel_event;
+
+ struct work_struct scan_work;
+ struct work_struct state_work;
+};
+
+/*
+ * SMD channel states.
+ */
+enum smd_channel_state {
+ SMD_CHANNEL_CLOSED,
+ SMD_CHANNEL_OPENING,
+ SMD_CHANNEL_OPENED,
+ SMD_CHANNEL_FLUSHING,
+ SMD_CHANNEL_CLOSING,
+ SMD_CHANNEL_RESET,
+ SMD_CHANNEL_RESET_OPENING
+};
+
+struct qcom_smd_device {
+ struct rpmsg_device rpdev;
+
+ struct qcom_smd_edge *edge;
+};
+
+struct qcom_smd_endpoint {
+ struct rpmsg_endpoint ept;
+
+ struct qcom_smd_channel *qsch;
+};
+
+#define to_smd_device(_rpdev) container_of(_rpdev, struct qcom_smd_device, rpdev)
+#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
+#define to_smd_endpoint(ept) container_of(ept, struct qcom_smd_endpoint, ept)
+
+/**
+ * struct qcom_smd_channel - smd channel struct
+ * @edge: qcom_smd_edge this channel is living on
+ * @qsdev: reference to a associated smd client device
+ * @name: name of the channel
+ * @state: local state of the channel
+ * @remote_state: remote state of the channel
+ * @info: byte aligned outgoing/incoming channel info
+ * @info_word: word aligned outgoing/incoming channel info
+ * @tx_lock: lock to make writes to the channel mutually exclusive
+ * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
+ * @tx_fifo: pointer to the outgoing ring buffer
+ * @rx_fifo: pointer to the incoming ring buffer
+ * @fifo_size: size of each ring buffer
+ * @bounce_buffer: bounce buffer for reading wrapped packets
+ * @cb: callback function registered for this channel
+ * @recv_lock: guard for rx info modifications and cb pointer
+ * @pkt_size: size of the currently handled packet
+ * @list: lite entry for @channels in qcom_smd_edge
+ */
+struct qcom_smd_channel {
+ struct qcom_smd_edge *edge;
+
+ struct qcom_smd_endpoint *qsept;
+ bool registered;
+
+ char *name;
+ enum smd_channel_state state;
+ enum smd_channel_state remote_state;
+
+ struct smd_channel_info_pair *info;
+ struct smd_channel_info_word_pair *info_word;
+
+ struct mutex tx_lock;
+ wait_queue_head_t fblockread_event;
+
+ void *tx_fifo;
+ void *rx_fifo;
+ int fifo_size;
+
+ void *bounce_buffer;
+
+ spinlock_t recv_lock;
+
+ int pkt_size;
+
+ void *drvdata;
+
+ struct list_head list;
+};
+
+/*
+ * Format of the smd_info smem items, for byte aligned channels.
+ */
+struct smd_channel_info {
+ __le32 state;
+ u8 fDSR;
+ u8 fCTS;
+ u8 fCD;
+ u8 fRI;
+ u8 fHEAD;
+ u8 fTAIL;
+ u8 fSTATE;
+ u8 fBLOCKREADINTR;
+ __le32 tail;
+ __le32 head;
+};
+
+struct smd_channel_info_pair {
+ struct smd_channel_info tx;
+ struct smd_channel_info rx;
+};
+
+/*
+ * Format of the smd_info smem items, for word aligned channels.
+ */
+struct smd_channel_info_word {
+ __le32 state;
+ __le32 fDSR;
+ __le32 fCTS;
+ __le32 fCD;
+ __le32 fRI;
+ __le32 fHEAD;
+ __le32 fTAIL;
+ __le32 fSTATE;
+ __le32 fBLOCKREADINTR;
+ __le32 tail;
+ __le32 head;
+};
+
+struct smd_channel_info_word_pair {
+ struct smd_channel_info_word tx;
+ struct smd_channel_info_word rx;
+};
+
+#define GET_RX_CHANNEL_FLAG(channel, param) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
+ channel->info_word ? \
+ le32_to_cpu(channel->info_word->rx.param) : \
+ channel->info->rx.param; \
+ })
+
+#define GET_RX_CHANNEL_INFO(channel, param) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
+ le32_to_cpu(channel->info_word ? \
+ channel->info_word->rx.param : \
+ channel->info->rx.param); \
+ })
+
+#define SET_RX_CHANNEL_FLAG(channel, param, value) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
+ if (channel->info_word) \
+ channel->info_word->rx.param = cpu_to_le32(value); \
+ else \
+ channel->info->rx.param = value; \
+ })
+
+#define SET_RX_CHANNEL_INFO(channel, param, value) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
+ if (channel->info_word) \
+ channel->info_word->rx.param = cpu_to_le32(value); \
+ else \
+ channel->info->rx.param = cpu_to_le32(value); \
+ })
+
+#define GET_TX_CHANNEL_FLAG(channel, param) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
+ channel->info_word ? \
+ le32_to_cpu(channel->info_word->tx.param) : \
+ channel->info->tx.param; \
+ })
+
+#define GET_TX_CHANNEL_INFO(channel, param) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
+ le32_to_cpu(channel->info_word ? \
+ channel->info_word->tx.param : \
+ channel->info->tx.param); \
+ })
+
+#define SET_TX_CHANNEL_FLAG(channel, param, value) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
+ if (channel->info_word) \
+ channel->info_word->tx.param = cpu_to_le32(value); \
+ else \
+ channel->info->tx.param = value; \
+ })
+
+#define SET_TX_CHANNEL_INFO(channel, param, value) \
+ ({ \
+ BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
+ if (channel->info_word) \
+ channel->info_word->tx.param = cpu_to_le32(value); \
+ else \
+ channel->info->tx.param = cpu_to_le32(value); \
+ })
+
+/**
+ * struct qcom_smd_alloc_entry - channel allocation entry
+ * @name: channel name
+ * @cid: channel index
+ * @flags: channel flags and edge id
+ * @ref_count: reference count of the channel
+ */
+struct qcom_smd_alloc_entry {
+ u8 name[20];
+ __le32 cid;
+ __le32 flags;
+ __le32 ref_count;
+} __packed;
+
+#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
+#define SMD_CHANNEL_FLAGS_STREAM BIT(8)
+#define SMD_CHANNEL_FLAGS_PACKET BIT(9)
+
+/*
+ * Each smd packet contains a 20 byte header, with the first 4 being the length
+ * of the packet.
+ */
+#define SMD_PACKET_HEADER_LEN 20
+
+/*
+ * Signal the remote processor associated with 'channel'.
+ */
+static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
+{
+ struct qcom_smd_edge *edge = channel->edge;
+
+ regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
+}
+
+/*
+ * Initialize the tx channel info
+ */
+static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
+{
+ SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
+ SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
+ SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
+ SET_TX_CHANNEL_FLAG(channel, fCD, 0);
+ SET_TX_CHANNEL_FLAG(channel, fRI, 0);
+ SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
+ SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
+ SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
+ SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
+ SET_TX_CHANNEL_INFO(channel, head, 0);
+ SET_RX_CHANNEL_INFO(channel, tail, 0);
+
+ qcom_smd_signal_channel(channel);
+
+ channel->state = SMD_CHANNEL_CLOSED;
+ channel->pkt_size = 0;
+}
+
+/*
+ * Set the callback for a channel, with appropriate locking
+ */
+static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
+ rpmsg_rx_cb_t cb)
+{
+ struct rpmsg_endpoint *ept = &channel->qsept->ept;
+ unsigned long flags;
+
+ spin_lock_irqsave(&channel->recv_lock, flags);
+ ept->cb = cb;
+ spin_unlock_irqrestore(&channel->recv_lock, flags);
+};
+
+/*
+ * Calculate the amount of data available in the rx fifo
+ */
+static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
+{
+ unsigned head;
+ unsigned tail;
+
+ head = GET_RX_CHANNEL_INFO(channel, head);
+ tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+ return (head - tail) & (channel->fifo_size - 1);
+}
+
+/*
+ * Set tx channel state and inform the remote processor
+ */
+static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
+ int state)
+{
+ struct qcom_smd_edge *edge = channel->edge;
+ bool is_open = state == SMD_CHANNEL_OPENED;
+
+ if (channel->state == state)
+ return;
+
+ dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
+
+ SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
+ SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
+ SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
+
+ SET_TX_CHANNEL_INFO(channel, state, state);
+ SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
+
+ channel->state = state;
+ qcom_smd_signal_channel(channel);
+}
+
+/*
+ * Copy count bytes of data using 32bit accesses, if that's required.
+ */
+static void smd_copy_to_fifo(void __iomem *dst,
+ const void *src,
+ size_t count,
+ bool word_aligned)
+{
+ if (word_aligned) {
+ __iowrite32_copy(dst, src, count / sizeof(u32));
+ } else {
+ memcpy_toio(dst, src, count);
+ }
+}
+
+/*
+ * Copy count bytes of data using 32bit accesses, if that is required.
+ */
+static void smd_copy_from_fifo(void *dst,
+ const void __iomem *src,
+ size_t count,
+ bool word_aligned)
+{
+ if (word_aligned) {
+ __ioread32_copy(dst, src, count / sizeof(u32));
+ } else {
+ memcpy_fromio(dst, src, count);
+ }
+}
+
+/*
+ * Read count bytes of data from the rx fifo into buf, but don't advance the
+ * tail.
+ */
+static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
+ void *buf, size_t count)
+{
+ bool word_aligned;
+ unsigned tail;
+ size_t len;
+
+ word_aligned = channel->info_word;
+ tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+ len = min_t(size_t, count, channel->fifo_size - tail);
+ if (len) {
+ smd_copy_from_fifo(buf,
+ channel->rx_fifo + tail,
+ len,
+ word_aligned);
+ }
+
+ if (len != count) {
+ smd_copy_from_fifo(buf + len,
+ channel->rx_fifo,
+ count - len,
+ word_aligned);
+ }
+
+ return count;
+}
+
+/*
+ * Advance the rx tail by count bytes.
+ */
+static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
+ size_t count)
+{
+ unsigned tail;
+
+ tail = GET_RX_CHANNEL_INFO(channel, tail);
+ tail += count;
+ tail &= (channel->fifo_size - 1);
+ SET_RX_CHANNEL_INFO(channel, tail, tail);
+}
+
+/*
+ * Read out a single packet from the rx fifo and deliver it to the device
+ */
+static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
+{
+ struct rpmsg_endpoint *ept = &channel->qsept->ept;
+ unsigned tail;
+ size_t len;
+ void *ptr;
+ int ret;
+
+ tail = GET_RX_CHANNEL_INFO(channel, tail);
+
+ /* Use bounce buffer if the data wraps */
+ if (tail + channel->pkt_size >= channel->fifo_size) {
+ ptr = channel->bounce_buffer;
+ len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
+ } else {
+ ptr = channel->rx_fifo + tail;
+ len = channel->pkt_size;
+ }
+
+ ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
+ if (ret < 0)
+ return ret;
+
+ /* Only forward the tail if the client consumed the data */
+ qcom_smd_channel_advance(channel, len);
+
+ channel->pkt_size = 0;
+
+ return 0;
+}
+
+/*
+ * Per channel interrupt handling
+ */
+static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
+{
+ bool need_state_scan = false;
+ int remote_state;
+ __le32 pktlen;
+ int avail;
+ int ret;
+
+ /* Handle state changes */
+ remote_state = GET_RX_CHANNEL_INFO(channel, state);
+ if (remote_state != channel->remote_state) {
+ channel->remote_state = remote_state;
+ need_state_scan = true;
+ }
+ /* Indicate that we have seen any state change */
+ SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
+
+ /* Signal waiting qcom_smd_send() about the interrupt */
+ if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
+ wake_up_interruptible(&channel->fblockread_event);
+
+ /* Don't consume any data until we've opened the channel */
+ if (channel->state != SMD_CHANNEL_OPENED)
+ goto out;
+
+ /* Indicate that we've seen the new data */
+ SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
+
+ /* Consume data */
+ for (;;) {
+ avail = qcom_smd_channel_get_rx_avail(channel);
+
+ if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
+ qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
+ qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
+ channel->pkt_size = le32_to_cpu(pktlen);
+ } else if (channel->pkt_size && avail >= channel->pkt_size) {
+ ret = qcom_smd_channel_recv_single(channel);
+ if (ret)
+ break;
+ } else {
+ break;
+ }
+ }
+
+ /* Indicate that we have seen and updated tail */
+ SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
+
+ /* Signal the remote that we've consumed the data (if requested) */
+ if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
+ /* Ensure ordering of channel info updates */
+ wmb();
+
+ qcom_smd_signal_channel(channel);
+ }
+
+out:
+ return need_state_scan;
+}
+
+/*
+ * The edge interrupts are triggered by the remote processor on state changes,
+ * channel info updates or when new channels are created.
+ */
+static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
+{
+ struct qcom_smd_edge *edge = data;
+ struct qcom_smd_channel *channel;
+ unsigned available;
+ bool kick_scanner = false;
+ bool kick_state = false;
+
+ /*
+ * Handle state changes or data on each of the channels on this edge
+ */
+ spin_lock(&edge->channels_lock);
+ list_for_each_entry(channel, &edge->channels, list) {
+ spin_lock(&channel->recv_lock);
+ kick_state |= qcom_smd_channel_intr(channel);
+ spin_unlock(&channel->recv_lock);
+ }
+ spin_unlock(&edge->channels_lock);
+
+ /*
+ * Creating a new channel requires allocating an smem entry, so we only
+ * have to scan if the amount of available space in smem have changed
+ * since last scan.
+ */
+ available = qcom_smem_get_free_space(edge->remote_pid);
+ if (available != edge->smem_available) {
+ edge->smem_available = available;
+ kick_scanner = true;
+ }
+
+ if (kick_scanner)
+ schedule_work(&edge->scan_work);
+ if (kick_state)
+ schedule_work(&edge->state_work);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Calculate how much space is available in the tx fifo.
+ */
+static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
+{
+ unsigned head;
+ unsigned tail;
+ unsigned mask = channel->fifo_size - 1;
+
+ head = GET_TX_CHANNEL_INFO(channel, head);
+ tail = GET_TX_CHANNEL_INFO(channel, tail);
+
+ return mask - ((head - tail) & mask);
+}
+
+/*
+ * Write count bytes of data into channel, possibly wrapping in the ring buffer
+ */
+static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
+ const void *data,
+ size_t count)
+{
+ bool word_aligned;
+ unsigned head;
+ size_t len;
+
+ word_aligned = channel->info_word;
+ head = GET_TX_CHANNEL_INFO(channel, head);
+
+ len = min_t(size_t, count, channel->fifo_size - head);
+ if (len) {
+ smd_copy_to_fifo(channel->tx_fifo + head,
+ data,
+ len,
+ word_aligned);
+ }
+
+ if (len != count) {
+ smd_copy_to_fifo(channel->tx_fifo,
+ data + len,
+ count - len,
+ word_aligned);
+ }
+
+ head += count;
+ head &= (channel->fifo_size - 1);
+ SET_TX_CHANNEL_INFO(channel, head, head);
+
+ return count;
+}
+
+/**
+ * qcom_smd_send - write data to smd channel
+ * @channel: channel handle
+ * @data: buffer of data to write
+ * @len: number of bytes to write
+ *
+ * This is a blocking write of len bytes into the channel's tx ring buffer and
+ * signal the remote end. It will sleep until there is enough space available
+ * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
+ * polling.
+ */
+static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
+ int len, bool wait)
+{
+ __le32 hdr[5] = { cpu_to_le32(len), };
+ int tlen = sizeof(hdr) + len;
+ int ret;
+
+ /* Word aligned channels only accept word size aligned data */
+ if (channel->info_word && len % 4)
+ return -EINVAL;
+
+ /* Reject packets that are too big */
+ if (tlen >= channel->fifo_size)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&channel->tx_lock);
+ if (ret)
+ return ret;
+
+ while (qcom_smd_get_tx_avail(channel) < tlen) {
+ if (!wait) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (channel->state != SMD_CHANNEL_OPENED) {
+ ret = -EPIPE;
+ goto out;
+ }
+
+ SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
+
+ ret = wait_event_interruptible(channel->fblockread_event,
+ qcom_smd_get_tx_avail(channel) >= tlen ||
+ channel->state != SMD_CHANNEL_OPENED);
+ if (ret)
+ goto out;
+
+ SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
+ }
+
+ SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
+
+ qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
+ qcom_smd_write_fifo(channel, data, len);
+
+ SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
+
+ /* Ensure ordering of channel info updates */
+ wmb();
+
+ qcom_smd_signal_channel(channel);
+
+out:
+ mutex_unlock(&channel->tx_lock);
+
+ return ret;
+}
+
+/*
+ * Helper for opening a channel
+ */
+static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
+ rpmsg_rx_cb_t cb)
+{
+ size_t bb_size;
+
+ /*
+ * Packets are maximum 4k, but reduce if the fifo is smaller
+ */
+ bb_size = min(channel->fifo_size, SZ_4K);
+ channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
+ if (!channel->bounce_buffer)
+ return -ENOMEM;
+
+ qcom_smd_channel_set_callback(channel, cb);
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
+
+ return 0;
+}
+
+/*
+ * Helper for closing and resetting a channel
+ */
+static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
+{
+ qcom_smd_channel_set_callback(channel, NULL);
+
+ kfree(channel->bounce_buffer);
+ channel->bounce_buffer = NULL;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+ qcom_smd_channel_reset(channel);
+}
+
+static struct qcom_smd_channel *
+qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_channel *ret = NULL;
+ unsigned long flags;
+ unsigned state;
+
+ spin_lock_irqsave(&edge->channels_lock, flags);
+ list_for_each_entry(channel, &edge->channels, list) {
+ if (strcmp(channel->name, name))
+ continue;
+
+ state = GET_RX_CHANNEL_INFO(channel, state);
+ if (state != SMD_CHANNEL_OPENING &&
+ state != SMD_CHANNEL_OPENED)
+ continue;
+
+ ret = channel;
+ break;
+ }
+ spin_unlock_irqrestore(&edge->channels_lock, flags);
+
+ return ret;
+}
+
+static void __ept_release(struct kref *kref)
+{
+ struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
+ refcount);
+ kfree(to_smd_endpoint(ept));
+}
+
+static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
+ rpmsg_rx_cb_t cb, void *priv,
+ struct rpmsg_channel_info chinfo)
+{
+ struct qcom_smd_endpoint *qsept;
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_device *qsdev = to_smd_device(rpdev);
+ struct qcom_smd_edge *edge = qsdev->edge;
+ struct rpmsg_endpoint *ept;
+ const char *name = chinfo.name;
+ int ret;
+
+ /* Wait up to HZ for the channel to appear */
+ ret = wait_event_interruptible_timeout(edge->new_channel_event,
+ (channel = qcom_smd_find_channel(edge, name)) != NULL,
+ HZ);
+ if (!ret)
+ return NULL;
+
+ if (channel->state != SMD_CHANNEL_CLOSED) {
+ dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
+ return NULL;
+ }
+
+ qsept = kzalloc(sizeof(*qsept), GFP_KERNEL);
+ if (!qsept)
+ return NULL;
+
+ ept = &qsept->ept;
+
+ kref_init(&ept->refcount);
+
+ ept->rpdev = rpdev;
+ ept->cb = cb;
+ ept->priv = priv;
+ ept->ops = &qcom_smd_endpoint_ops;
+
+ channel->qsept = qsept;
+ qsept->qsch = channel;
+
+ ret = qcom_smd_channel_open(channel, cb);
+ if (ret)
+ goto free_ept;
+
+ return ept;
+
+free_ept:
+ channel->qsept = NULL;
+ kref_put(&ept->refcount, __ept_release);
+ return NULL;
+}
+
+static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
+{
+ struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
+ struct qcom_smd_channel *ch = qsept->qsch;
+
+ qcom_smd_channel_close(ch);
+ ch->qsept = NULL;
+ kref_put(&ept->refcount, __ept_release);
+}
+
+static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len)
+{
+ struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
+
+ return __qcom_smd_send(qsept->qsch, data, len, true);
+}
+
+static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
+{
+ struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
+
+ return __qcom_smd_send(qsept->qsch, data, len, false);
+}
+
+/*
+ * Finds the device_node for the smd child interested in this channel.
+ */
+static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
+ const char *channel)
+{
+ struct device_node *child;
+ const char *name;
+ const char *key;
+ int ret;
+
+ for_each_available_child_of_node(edge_node, child) {
+ key = "qcom,smd-channels";
+ ret = of_property_read_string(child, key, &name);
+ if (ret)
+ continue;
+
+ if (strcmp(name, channel) == 0)
+ return child;
+ }
+
+ return NULL;
+}
+
+static const struct rpmsg_device_ops qcom_smd_device_ops = {
+ .create_ept = qcom_smd_create_ept,
+};
+
+static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
+ .destroy_ept = qcom_smd_destroy_ept,
+ .send = qcom_smd_send,
+ .trysend = qcom_smd_trysend,
+};
+
+/*
+ * Create a smd client device for channel that is being opened.
+ */
+static int qcom_smd_create_device(struct qcom_smd_channel *channel)
+{
+ struct qcom_smd_device *qsdev;
+ struct rpmsg_device *rpdev;
+ struct qcom_smd_edge *edge = channel->edge;
+
+ dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
+
+ qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
+ if (!qsdev)
+ return -ENOMEM;
+
+ /* Link qsdev to our SMD edge */
+ qsdev->edge = edge;
+
+ /* Assign callbacks for rpmsg_device */
+ qsdev->rpdev.ops = &qcom_smd_device_ops;
+
+ /* Assign public information to the rpmsg_device */
+ rpdev = &qsdev->rpdev;
+ strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
+ rpdev->src = RPMSG_ADDR_ANY;
+ rpdev->dst = RPMSG_ADDR_ANY;
+
+ rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
+ rpdev->dev.parent = &edge->dev;
+
+ return rpmsg_register_device(rpdev);
+}
+
+/*
+ * Allocate the qcom_smd_channel object for a newly found smd channel,
+ * retrieving and validating the smem items involved.
+ */
+static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
+ unsigned smem_info_item,
+ unsigned smem_fifo_item,
+ char *name)
+{
+ struct qcom_smd_channel *channel;
+ size_t fifo_size;
+ size_t info_size;
+ void *fifo_base;
+ void *info;
+ int ret;
+
+ channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL);
+ if (!channel)
+ return ERR_PTR(-ENOMEM);
+
+ channel->edge = edge;
+ channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL);
+ if (!channel->name)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&channel->tx_lock);
+ spin_lock_init(&channel->recv_lock);
+ init_waitqueue_head(&channel->fblockread_event);
+
+ info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
+ if (IS_ERR(info)) {
+ ret = PTR_ERR(info);
+ goto free_name_and_channel;
+ }
+
+ /*
+ * Use the size of the item to figure out which channel info struct to
+ * use.
+ */
+ if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
+ channel->info_word = info;
+ } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
+ channel->info = info;
+ } else {
+ dev_err(&edge->dev,
+ "channel info of size %zu not supported\n", info_size);
+ ret = -EINVAL;
+ goto free_name_and_channel;
+ }
+
+ fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
+ if (IS_ERR(fifo_base)) {
+ ret = PTR_ERR(fifo_base);
+ goto free_name_and_channel;
+ }
+
+ /* The channel consist of a rx and tx fifo of equal size */
+ fifo_size /= 2;
+
+ dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
+ name, info_size, fifo_size);
+
+ channel->tx_fifo = fifo_base;
+ channel->rx_fifo = fifo_base + fifo_size;
+ channel->fifo_size = fifo_size;
+
+ qcom_smd_channel_reset(channel);
+
+ return channel;
+
+free_name_and_channel:
+ devm_kfree(&edge->dev, channel->name);
+ devm_kfree(&edge->dev, channel);
+
+ return ERR_PTR(ret);
+}
+
+/*
+ * Scans the allocation table for any newly allocated channels, calls
+ * qcom_smd_create_channel() to create representations of these and add
+ * them to the edge's list of channels.
+ */
+static void qcom_channel_scan_worker(struct work_struct *work)
+{
+ struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
+ struct qcom_smd_alloc_entry *alloc_tbl;
+ struct qcom_smd_alloc_entry *entry;
+ struct qcom_smd_channel *channel;
+ unsigned long flags;
+ unsigned fifo_id;
+ unsigned info_id;
+ int tbl;
+ int i;
+ u32 eflags, cid;
+
+ for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
+ alloc_tbl = qcom_smem_get(edge->remote_pid,
+ smem_items[tbl].alloc_tbl_id, NULL);
+ if (IS_ERR(alloc_tbl))
+ continue;
+
+ for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
+ entry = &alloc_tbl[i];
+ eflags = le32_to_cpu(entry->flags);
+ if (test_bit(i, edge->allocated[tbl]))
+ continue;
+
+ if (entry->ref_count == 0)
+ continue;
+
+ if (!entry->name[0])
+ continue;
+
+ if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
+ continue;
+
+ if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
+ continue;
+
+ cid = le32_to_cpu(entry->cid);
+ info_id = smem_items[tbl].info_base_id + cid;
+ fifo_id = smem_items[tbl].fifo_base_id + cid;
+
+ channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
+ if (IS_ERR(channel))
+ continue;
+
+ spin_lock_irqsave(&edge->channels_lock, flags);
+ list_add(&channel->list, &edge->channels);
+ spin_unlock_irqrestore(&edge->channels_lock, flags);
+
+ dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
+ set_bit(i, edge->allocated[tbl]);
+
+ wake_up_interruptible(&edge->new_channel_event);
+ }
+ }
+
+ schedule_work(&edge->state_work);
+}
+
+/*
+ * This per edge worker scans smem for any new channels and register these. It
+ * then scans all registered channels for state changes that should be handled
+ * by creating or destroying smd client devices for the registered channels.
+ *
+ * LOCKING: edge->channels_lock only needs to cover the list operations, as the
+ * worker is killed before any channels are deallocated
+ */
+static void qcom_channel_state_worker(struct work_struct *work)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_edge *edge = container_of(work,
+ struct qcom_smd_edge,
+ state_work);
+ struct rpmsg_channel_info chinfo;
+ unsigned remote_state;
+ unsigned long flags;
+
+ /*
+ * Register a device for any closed channel where the remote processor
+ * is showing interest in opening the channel.
+ */
+ spin_lock_irqsave(&edge->channels_lock, flags);
+ list_for_each_entry(channel, &edge->channels, list) {
+ if (channel->state != SMD_CHANNEL_CLOSED)
+ continue;
+
+ remote_state = GET_RX_CHANNEL_INFO(channel, state);
+ if (remote_state != SMD_CHANNEL_OPENING &&
+ remote_state != SMD_CHANNEL_OPENED)
+ continue;
+
+ if (channel->registered)
+ continue;
+
+ spin_unlock_irqrestore(&edge->channels_lock, flags);
+ qcom_smd_create_device(channel);
+ channel->registered = true;
+ spin_lock_irqsave(&edge->channels_lock, flags);
+
+ channel->registered = true;
+ }
+
+ /*
+ * Unregister the device for any channel that is opened where the
+ * remote processor is closing the channel.
+ */
+ list_for_each_entry(channel, &edge->channels, list) {
+ if (channel->state != SMD_CHANNEL_OPENING &&
+ channel->state != SMD_CHANNEL_OPENED)
+ continue;
+
+ remote_state = GET_RX_CHANNEL_INFO(channel, state);
+ if (remote_state == SMD_CHANNEL_OPENING ||
+ remote_state == SMD_CHANNEL_OPENED)
+ continue;
+
+ spin_unlock_irqrestore(&edge->channels_lock, flags);
+
+ strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
+ chinfo.src = RPMSG_ADDR_ANY;
+ chinfo.dst = RPMSG_ADDR_ANY;
+ rpmsg_unregister_device(&edge->dev, &chinfo);
+ channel->registered = false;
+ spin_lock_irqsave(&edge->channels_lock, flags);
+ }
+ spin_unlock_irqrestore(&edge->channels_lock, flags);
+}
+
+/*
+ * Parses an of_node describing an edge.
+ */
+static int qcom_smd_parse_edge(struct device *dev,
+ struct device_node *node,
+ struct qcom_smd_edge *edge)
+{
+ struct device_node *syscon_np;
+ const char *key;
+ int irq;
+ int ret;
+
+ INIT_LIST_HEAD(&edge->channels);
+ spin_lock_init(&edge->channels_lock);
+
+ INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
+ INIT_WORK(&edge->state_work, qcom_channel_state_worker);
+
+ edge->of_node = of_node_get(node);
+
+ key = "qcom,smd-edge";
+ ret = of_property_read_u32(node, key, &edge->edge_id);
+ if (ret) {
+ dev_err(dev, "edge missing %s property\n", key);
+ return -EINVAL;
+ }
+
+ edge->remote_pid = QCOM_SMEM_HOST_ANY;
+ key = "qcom,remote-pid";
+ of_property_read_u32(node, key, &edge->remote_pid);
+
+ syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
+ if (!syscon_np) {
+ dev_err(dev, "no qcom,ipc node\n");
+ return -ENODEV;
+ }
+
+ edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
+ if (IS_ERR(edge->ipc_regmap))
+ return PTR_ERR(edge->ipc_regmap);
+
+ key = "qcom,ipc";
+ ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
+ if (ret < 0) {
+ dev_err(dev, "no offset in %s\n", key);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
+ if (ret < 0) {
+ dev_err(dev, "no bit in %s\n", key);
+ return -EINVAL;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq < 0) {
+ dev_err(dev, "required smd interrupt missing\n");
+ return -EINVAL;
+ }
+
+ ret = devm_request_irq(dev, irq,
+ qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
+ node->name, edge);
+ if (ret) {
+ dev_err(dev, "failed to request smd irq\n");
+ return ret;
+ }
+
+ edge->irq = irq;
+
+ return 0;
+}
+
+/*
+ * Release function for an edge.
+ * Reset the state of each associated channel and free the edge context.
+ */
+static void qcom_smd_edge_release(struct device *dev)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_edge *edge = to_smd_edge(dev);
+
+ list_for_each_entry(channel, &edge->channels, list) {
+ SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
+ SET_RX_CHANNEL_INFO(channel, head, 0);
+ SET_RX_CHANNEL_INFO(channel, tail, 0);
+ }
+
+ kfree(edge);
+}
+
+/**
+ * qcom_smd_register_edge() - register an edge based on an device_node
+ * @parent: parent device for the edge
+ * @node: device_node describing the edge
+ *
+ * Returns an edge reference, or negative ERR_PTR() on failure.
+ */
+struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
+ struct device_node *node)
+{
+ struct qcom_smd_edge *edge;
+ int ret;
+
+ edge = kzalloc(sizeof(*edge), GFP_KERNEL);
+ if (!edge)
+ return ERR_PTR(-ENOMEM);
+
+ init_waitqueue_head(&edge->new_channel_event);
+
+ edge->dev.parent = parent;
+ edge->dev.release = qcom_smd_edge_release;
+ dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
+ ret = device_register(&edge->dev);
+ if (ret) {
+ pr_err("failed to register smd edge\n");
+ return ERR_PTR(ret);
+ }
+
+ ret = qcom_smd_parse_edge(&edge->dev, node, edge);
+ if (ret) {
+ dev_err(&edge->dev, "failed to parse smd edge\n");
+ goto unregister_dev;
+ }
+
+ schedule_work(&edge->scan_work);
+
+ return edge;
+
+unregister_dev:
+ put_device(&edge->dev);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(qcom_smd_register_edge);
+
+static int qcom_smd_remove_device(struct device *dev, void *data)
+{
+ device_unregister(dev);
+
+ return 0;
+}
+
+/**
+ * qcom_smd_unregister_edge() - release an edge and its children
+ * @edge: edge reference acquired from qcom_smd_register_edge
+ */
+int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
+{
+ int ret;
+
+ disable_irq(edge->irq);
+ cancel_work_sync(&edge->scan_work);
+ cancel_work_sync(&edge->state_work);
+
+ ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
+ if (ret)
+ dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
+
+ device_unregister(&edge->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL(qcom_smd_unregister_edge);
+
+static int qcom_smd_probe(struct platform_device *pdev)
+{
+ struct device_node *node;
+ void *p;
+
+ /* Wait for smem */
+ p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
+ if (PTR_ERR(p) == -EPROBE_DEFER)
+ return PTR_ERR(p);
+
+ for_each_available_child_of_node(pdev->dev.of_node, node)
+ qcom_smd_register_edge(&pdev->dev, node);
+
+ return 0;
+}
+
+static int qcom_smd_remove_edge(struct device *dev, void *data)
+{
+ struct qcom_smd_edge *edge = to_smd_edge(dev);
+
+ return qcom_smd_unregister_edge(edge);
+}
+
+/*
+ * Shut down all smd clients by making sure that each edge stops processing
+ * events and scanning for new channels, then call destroy on the devices.
+ */
+static int qcom_smd_remove(struct platform_device *pdev)
+{
+ int ret;
+
+ ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
+ if (ret)
+ dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret);
+
+ return ret;
+}
+
+static const struct of_device_id qcom_smd_of_match[] = {
+ { .compatible = "qcom,smd" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
+
+static struct platform_driver qcom_smd_driver = {
+ .probe = qcom_smd_probe,
+ .remove = qcom_smd_remove,
+ .driver = {
+ .name = "qcom-smd",
+ .of_match_table = qcom_smd_of_match,
+ },
+};
+
+static int __init qcom_smd_init(void)
+{
+ return platform_driver_register(&qcom_smd_driver);
+}
+subsys_initcall(qcom_smd_init);
+
+static void __exit qcom_smd_exit(void)
+{
+ platform_driver_unregister(&qcom_smd_driver);
+}
+module_exit(qcom_smd_exit);
+
+MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
+MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
+MODULE_LICENSE("GPL v2");
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff