diff options
Diffstat (limited to 'drivers/rpmsg/qcom_smd.c')
| -rw-r--r-- | drivers/rpmsg/qcom_smd.c | 1622 |
1 files changed, 1622 insertions, 0 deletions
diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c new file mode 100644 index 000000000..1044cf03c --- /dev/null +++ b/drivers/rpmsg/qcom_smd.c @@ -0,0 +1,1622 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2015, Sony Mobile Communications AB. + * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. + */ + +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/mailbox_client.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/sizes.h> +#include <linux/slab.h> +#include <linux/soc/qcom/smem.h> +#include <linux/wait.h> +#include <linux/rpmsg.h> +#include <linux/rpmsg/qcom_smd.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 + * @dev: device associated with this edge + * @name: name of this edge + * @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 + * @mbox_client: mailbox client handle + * @mbox_chan: apcs ipc mailbox channel handle + * @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 + * @new_channel_event: wait queue for new channel events + * @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 mbox_client mbox_client; + struct mbox_chan *mbox_chan; + + 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(r) container_of(r, struct qcom_smd_device, rpdev) +#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev) +#define to_smd_endpoint(e) container_of(e, struct qcom_smd_endpoint, ept) + +/** + * struct qcom_smd_channel - smd channel struct + * @edge: qcom_smd_edge this channel is living on + * @qsept: reference to a associated smd endpoint + * @registered: flag to indicate if the channel is registered + * @name: name of the channel + * @state: local state of the channel + * @remote_state: remote state of the channel + * @state_change_event: state change event + * @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 + * @drvdata: driver private data + * @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; + + spinlock_t 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; + + if (edge->mbox_chan) { + /* + * We can ignore a failing mbox_send_message() as the only + * possible cause is that the FIFO in the framework is full of + * other writes to the same bit. + */ + mbox_send_message(edge->mbox_chan, NULL); + mbox_client_txdone(edge->mbox_chan, 0); + } else { + 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 + * @wait: flag to indicate if write can wait + * + * 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; + unsigned long flags; + 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; + + /* Highlight the fact that if we enter the loop below we might sleep */ + if (wait) + might_sleep(); + + spin_lock_irqsave(&channel->tx_lock, flags); + + while (qcom_smd_get_tx_avail(channel) < tlen && + channel->state == SMD_CHANNEL_OPENED) { + if (!wait) { + ret = -EAGAIN; + goto out_unlock; + } + + SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0); + + /* Wait without holding the tx_lock */ + spin_unlock_irqrestore(&channel->tx_lock, flags); + + ret = wait_event_interruptible(channel->fblockread_event, + qcom_smd_get_tx_avail(channel) >= tlen || + channel->state != SMD_CHANNEL_OPENED); + if (ret) + return ret; + + spin_lock_irqsave(&channel->tx_lock, flags); + + SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); + } + + /* Fail if the channel was closed */ + if (channel->state != SMD_CHANNEL_OPENED) { + ret = -EPIPE; + goto out_unlock; + } + + 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_unlock: + spin_unlock_irqrestore(&channel->tx_lock, flags); + + 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 int qcom_smd_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) +{ + struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); + + return __qcom_smd_send(qsept->qsch, data, len, true); +} + +static int qcom_smd_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) +{ + struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); + + return __qcom_smd_send(qsept->qsch, data, len, false); +} + +static __poll_t 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; + __poll_t mask = 0; + + poll_wait(filp, &channel->fblockread_event, wait); + + if (qcom_smd_get_tx_avail(channel) > 20) + mask |= EPOLLOUT | EPOLLWRNORM; + + 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 int qcom_smd_announce_create(struct rpmsg_device *rpdev) +{ + struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept); + struct qcom_smd_channel *channel = qept->qsch; + unsigned long flags; + bool kick_state; + + spin_lock_irqsave(&channel->recv_lock, flags); + kick_state = qcom_smd_channel_intr(channel); + spin_unlock_irqrestore(&channel->recv_lock, flags); + + if (kick_state) + schedule_work(&channel->edge->state_work); + + return 0; +} + +static const struct rpmsg_device_ops qcom_smd_device_ops = { + .create_ept = qcom_smd_create_ept, + .announce_create = qcom_smd_announce_create, +}; + +static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = { + .destroy_ept = qcom_smd_destroy_ept, + .send = qcom_smd_send, + .sendto = qcom_smd_sendto, + .trysend = qcom_smd_trysend, + .trysendto = qcom_smd_trysendto, + .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; + strscpy_pad(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_ctrldev_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 = kzalloc(sizeof(*channel), GFP_KERNEL); + if (!channel) + return ERR_PTR(-ENOMEM); + + channel->edge = edge; + channel->name = kstrdup(name, GFP_KERNEL); + if (!channel->name) { + ret = -ENOMEM; + goto free_channel; + } + + spin_lock_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: + kfree(channel->name); +free_channel: + kfree(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; + + /* + * Always open rpm_requests, even when already opened which is + * required on some SoCs like msm8953. + */ + remote_state = GET_RX_CHANNEL_INFO(channel, state); + if (remote_state != SMD_CHANNEL_OPENING && + remote_state != SMD_CHANNEL_OPENED && + strcmp(channel->name, "rpm_requests")) + continue; + + if (channel->registered) + continue; + + spin_unlock_irqrestore(&edge->channels_lock, flags); + qcom_smd_create_device(channel); + 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); + + strscpy_pad(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); + goto put_node; + } + + edge->remote_pid = QCOM_SMEM_HOST_ANY; + key = "qcom,remote-pid"; + of_property_read_u32(node, key, &edge->remote_pid); + + edge->mbox_client.dev = dev; + edge->mbox_client.knows_txdone = true; + edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0); + if (IS_ERR(edge->mbox_chan)) { + if (PTR_ERR(edge->mbox_chan) != -ENODEV) { + ret = PTR_ERR(edge->mbox_chan); + goto put_node; + } + + edge->mbox_chan = NULL; + + syscon_np = of_parse_phandle(node, "qcom,ipc", 0); + if (!syscon_np) { + dev_err(dev, "no qcom,ipc node\n"); + ret = -ENODEV; + goto put_node; + } + + edge->ipc_regmap = syscon_node_to_regmap(syscon_np); + of_node_put(syscon_np); + if (IS_ERR(edge->ipc_regmap)) { + ret = PTR_ERR(edge->ipc_regmap); + goto put_node; + } + + 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); + goto put_node; + } + + ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit); + if (ret < 0) { + dev_err(dev, "no bit in %s\n", key); + goto put_node; + } + } + + 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) { + dev_err(dev, "required smd interrupt missing\n"); + ret = -EINVAL; + goto put_node; + } + + 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"); + goto put_node; + } + + edge->irq = irq; + + return 0; + +put_node: + of_node_put(node); + edge->of_node = NULL; + + return ret; +} + +/* + * 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, *tmp; + struct qcom_smd_edge *edge = to_smd_edge(dev); + + list_for_each_entry_safe(channel, tmp, &edge->channels, list) { + list_del(&channel->list); + kfree(channel->name); + kfree(channel); + } + + 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 + * + * Return: 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:%pOFn", dev_name(parent), node); + ret = device_register(&edge->dev); + if (ret) { + pr_err("failed to register smd edge\n"); + put_device(&edge->dev); + 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: + if (!IS_ERR_OR_NULL(edge->mbox_chan)) + mbox_free_channel(edge->mbox_chan); + + device_unregister(&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); + + mbox_free_channel(edge->mbox_chan); + 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); +} +arch_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"); |