/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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; const char *name; 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; wait_queue_head_t state_change_event; 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; wake_up_interruptible_all(&channel->state_change_event); } /* 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_all(&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 = -EAGAIN; 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) { struct qcom_smd_edge *edge = channel->edge; size_t bb_size; int ret; /* * 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); /* Wait for remote to enter opening or opened */ ret = wait_event_interruptible_timeout(channel->state_change_event, channel->remote_state == SMD_CHANNEL_OPENING || channel->remote_state == SMD_CHANNEL_OPENED, HZ); if (!ret) { dev_err(&edge->dev, "remote side did not enter opening state\n"); goto out_close_timeout; } qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED); /* Wait for remote to enter opened */ ret = wait_event_interruptible_timeout(channel->state_change_event, channel->remote_state == SMD_CHANNEL_OPENED, HZ); if (!ret) { dev_err(&edge->dev, "remote side did not enter open state\n"); goto out_close_timeout; } return 0; out_close_timeout: qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED); return -ETIMEDOUT; } /* * 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; spin_lock_irqsave(&edge->channels_lock, flags); list_for_each_entry(channel, &edge->channels, list) { if (!strcmp(channel->name, name)) { 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); } static unsigned int qcom_smd_poll(struct rpmsg_endpoint *ept, struct file *filp, poll_table *wait) { struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); struct qcom_smd_channel *channel = qsept->qsch; unsigned int mask = 0; poll_wait(filp, &channel->fblockread_event, wait); if (qcom_smd_get_tx_avail(channel) > 20) mask |= POLLOUT | POLLWRNORM; return mask; } /* * 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, .poll = qcom_smd_poll, }; static void qcom_smd_release_device(struct device *dev) { struct rpmsg_device *rpdev = to_rpmsg_device(dev); struct qcom_smd_device *qsdev = to_smd_device(rpdev); kfree(qsdev); } /* * 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; rpdev->dev.release = qcom_smd_release_device; return rpmsg_register_device(rpdev); } static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge) { struct qcom_smd_device *qsdev; qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL); if (!qsdev) return -ENOMEM; qsdev->edge = edge; qsdev->rpdev.ops = &qcom_smd_device_ops; qsdev->rpdev.dev.parent = &edge->dev; qsdev->rpdev.dev.release = qcom_smd_release_device; return rpmsg_chrdev_register_device(&qsdev->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); init_waitqueue_head(&channel->state_change_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_all(&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; 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; } ret = of_property_read_string(node, "label", &edge->name); if (ret < 0) edge->name = node->name; 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); } static ssize_t rpmsg_name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct qcom_smd_edge *edge = to_smd_edge(dev); return sprintf(buf, "%s\n", edge->name); } static DEVICE_ATTR_RO(rpmsg_name); static struct attribute *qcom_smd_edge_attrs[] = { &dev_attr_rpmsg_name.attr, NULL }; ATTRIBUTE_GROUPS(qcom_smd_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; edge->dev.of_node = node; edge->dev.groups = qcom_smd_edge_groups; 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; } ret = qcom_smd_create_chrdev(edge); if (ret) { dev_err(&edge->dev, "failed to register chrdev for 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 "); MODULE_DESCRIPTION("Qualcomm Shared Memory Driver"); MODULE_LICENSE("GPL v2");