Messages in this thread Patch in this message | | | From | Sjur Brændeland <> | Subject | [PATCHv2 06/10] xshm: Add xshm device implementation | Date | Fri, 9 Dec 2011 15:07:24 +0100 |
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This patch implements the XSHM device. - Channel management such as open/close. - Modem start-up synchronization events. - C2C power request indications, requesting power-on when transmit is ongoing, and power-off upon inactivity timeout.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com> --- drivers/xshm/xshm_dev.c | 526 +++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 526 insertions(+), 0 deletions(-) create mode 100644 drivers/xshm/xshm_dev.c
diff --git a/drivers/xshm/xshm_dev.c b/drivers/xshm/xshm_dev.c new file mode 100644 index 0000000..9abe3ed --- /dev/null +++ b/drivers/xshm/xshm_dev.c @@ -0,0 +1,526 @@ +/* + * Copyright (C) ST-Ericsson AB 2011 + * Author: Sjur Brendeland / sjur.brandeland@stericsson.com + * License terms: GNU General Public License (GPL) version 2 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": %s :" fmt, __func__ +#include <linux/version.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/netdevice.h> +#include <linux/c2c_genio.h> +#include <linux/xshm/xshm_ipctoc.h> +#include <linux/xshm/xshm_dev.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sjur Brændland <sjur.brandeland@stericsson.com>"); +MODULE_DESCRIPTION("External Shared Memory - Supporting direct boot and IPC"); +MODULE_VERSION("XSHM 0.6 : " __DATE__); + +static int xshm_inactivity_timeout = 1000; +module_param(xshm_inactivity_timeout, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(xshm_inactivity_timeout, "Inactivity timeout, ms."); + +bool ready_for_ipc; +EXPORT_SYMBOL(ready_for_ipc); + +bool ready_for_caif; +EXPORT_SYMBOL(ready_for_caif); +static spinlock_t timer_lock; +static int inactivity_timeout; +static struct timer_list inactivity_timer; +static bool power_on; +static struct device _parentdev; +static struct device *parentdev; + +#if 1 +#define xdev_dbg(dev, fmt, arg...) printk(KERN_DEBUG "%s: %s - " fmt, \ + dev_name(&dev->dev), __func__, ##arg) +#define xdev_devl(dev, fmt, arg...) printk(KERN_DEBUG "%s: %s - " fmt, \ + dev_name(&dev->dev), __func__, ##arg) +#define pr_xshmstate(dev, str) \ + pr_devel("xshm: %s %s: %s STATE: %s txch:%s(%p) rxch:%s(%p)\n", \ + dev_name(&dev->dev), __func__, str, \ + dev->state == XSHM_DEV_OPEN ? "open" : "close", \ + *dev->cfg.tx.state == cpu_to_le32(XSHM_OPEN) ? \ + "open" : "close", \ + dev->cfg.tx.state, \ + *dev->cfg.rx.state == cpu_to_le32(XSHM_OPEN) ? \ + "open" : "close", \ + dev->cfg.rx.state) +#else +#define xdev_dbg(...) +#define xdev_devl(...) +#undef pr_debug +#undef pr_devel +#define pr_debug(...) +#define pr_devel(...) +#define pr_xshmstate(...) +#endif + +static void inactivity_tout(unsigned long arg) +{ + unsigned long flags; + pr_devel("enter\n"); + spin_lock_irqsave(&timer_lock, flags); + /* + * This is paranoia, but if timer is reactivated + * before this tout function is scheduled, + * we just ignore this timeout. + */ + if (timer_pending(&inactivity_timer)) + goto out; + + if (power_on) { + pr_devel("genio power req(off)\n"); + genio_power_req(false); + power_on = false; + } +out: + spin_unlock_irqrestore(&timer_lock, flags); +} + +static void activity(void) +{ + unsigned long flags; + pr_devel("enter\n"); + spin_lock_irqsave(&timer_lock, flags); + if (!power_on) { + pr_devel("genio power req(on)\n"); + genio_power_req(true); + power_on = true; + } + mod_timer(&inactivity_timer, + jiffies + inactivity_timeout); + spin_unlock_irqrestore(&timer_lock, flags); +} + +static void reset_activity_tout(void) +{ + unsigned long flags; + pr_devel("enter\n"); + spin_lock_irqsave(&timer_lock, flags); + if (power_on) { + genio_power_req(false); + power_on = false; + } + del_timer_sync(&inactivity_timer); + spin_unlock_irqrestore(&timer_lock, flags); +} + +static int xshmdev_ipc_tx(struct xshm_dev *dev) +{ + xdev_devl(dev, "call genio_set_bit(%d)\n", dev->cfg.tx.xfer_bit); + activity(); + return genio_set_bit(dev->cfg.tx.xfer_bit); +} + +static int xshmdev_ipc_rx_release(struct xshm_dev *dev, bool more) +{ + xdev_devl(dev, "call genio_set_bit(%d)\n", dev->cfg.tx.xfer_bit); + activity(); + return genio_set_bit(dev->cfg.rx.xfer_done_bit); +} + +static int do_open(struct xshm_dev *dev) +{ + int err; + + pr_xshmstate(dev, "enter"); + err = dev->open_cb(dev->driver_data); + if (err < 0) { + xdev_dbg(dev, "Error - open_cb failed\n"); + + /* Make sure ring-buffer is empty i RX and TX direction */ + *dev->cfg.rx.read = *dev->cfg.rx.write; + *dev->cfg.tx.write = *dev->cfg.tx.read; + *dev->cfg.tx.state = cpu_to_le32(XSHM_CLOSED); + xdev_devl(dev, "set state = XSHM_DEV_CLOSED\n"); + dev->state = XSHM_DEV_CLOSED; + return err; + } + + /* Check is we already have any data in the pipe */ + if (*dev->cfg.rx.write != *dev->cfg.rx.read) { + pr_devel("Received data during opening\n"); + dev->ipc_rx_cb(dev->driver_data); + } + + return err; +} + +static void genio_rx_cb(void *data) +{ + struct xshm_dev *dev = data; + + pr_xshmstate(dev, "Enter"); + + if (likely(dev->state == XSHM_DEV_OPEN)) { + if (unlikely(!ready_for_ipc)) { + xdev_devl(dev, "ready_for_ipc is not yet set\n"); + return; + } + + if (dev->ipc_rx_cb) { + int err = dev->ipc_rx_cb(dev->driver_data); + if (unlikely(err < 0)) + goto remote_close; + } + + } else if (*dev->cfg.rx.state == cpu_to_le32(XSHM_OPEN)) { + pr_xshmstate(dev, ""); + dev->state = XSHM_DEV_OPEN; + if (!ready_for_ipc) { + xdev_devl(dev, "ready_for_ipc is not yet set\n"); + return; + } + if (do_open(dev) < 0) + goto open_fail; + } + return; +open_fail: + pr_xshmstate(dev, "exit open failed"); + /* Make sure ring-buffer is empty i RX and TX direction */ + *dev->cfg.rx.read = *dev->cfg.rx.write; + *dev->cfg.tx.write = *dev->cfg.tx.read; +remote_close: + *dev->cfg.tx.state = cpu_to_le32(XSHM_CLOSED); + dev->state = XSHM_DEV_CLOSED; + dev->close_cb(dev->driver_data); +} + +static void genio_tx_release_cb(void *data) +{ + struct xshm_dev *dev = data; + + pr_xshmstate(dev, "Enter"); + if (!ready_for_ipc) { + xdev_devl(dev, "not ready_for_ipc\n"); + return; + } + if (dev->ipc_tx_release_cb) + dev->ipc_tx_release_cb(dev->driver_data); +} + +struct xshm_xgroup { + bool prohibit; + u32 group; +}; + +static void check_exclgroup(struct xshm_dev *dev, void *data) +{ + struct xshm_xgroup *x = data; + if (dev->state == XSHM_DEV_OPEN && + dev->cfg.excl_group != x->group) { + x->prohibit = true; + xdev_dbg(dev, "Exclusive group " + "prohibits device open\n"); + } +} + +static int xshmdev_open(struct xshm_dev *dev) +{ + int err = -EINVAL; + struct xshm_xgroup x = { + .prohibit = false, + .group = dev->cfg.excl_group + }; + + + pr_xshmstate(dev, "Enter"); + if (WARN_ON(dev->ipc_rx_cb == NULL) || + WARN_ON(dev->ipc_tx_release_cb == NULL) || + WARN_ON(dev->open_cb == NULL) || + WARN_ON(dev->close_cb == NULL)) + goto err; + + xshm_foreach_dev(check_exclgroup, &x); + if (x.prohibit) { + xdev_dbg(dev, "Exclusive group prohibits device open\n"); + err = -EPERM; + goto err; + } + + pr_devel("call genio_subscribe(%d)\n", dev->cfg.rx.xfer_bit); + err = genio_subscribe(dev->cfg.rx.xfer_bit, genio_rx_cb, dev); + if (err) + goto err; + + pr_devel("call genio_subscribe(%d)\n", dev->cfg.tx.xfer_done_bit); + err = genio_subscribe(dev->cfg.tx.xfer_done_bit, + genio_tx_release_cb, dev); + if (err) + goto err; + + /* Indicate that our side is open and ready for action */ + *dev->cfg.rx.read = *dev->cfg.rx.write; + *dev->cfg.tx.write = *dev->cfg.tx.read; + *dev->cfg.tx.state = cpu_to_le32(XSHM_OPEN); + + if (ready_for_ipc) + err = xshmdev_ipc_tx(dev); + + if (err < 0) { + xdev_dbg(dev, "can't update geno\n"); + goto err; + } + /* If other side is ready as well we're ready to role */ + if (*dev->cfg.rx.state == cpu_to_le32(XSHM_OPEN) && ready_for_ipc) { + if (do_open(dev) < 0) + goto err; + dev->state = XSHM_DEV_OPEN; + } + + return 0; +err: + pr_xshmstate(dev, "exit error"); + *dev->cfg.rx.read = *dev->cfg.rx.write; + *dev->cfg.tx.write = *dev->cfg.tx.read; + *dev->cfg.tx.state = cpu_to_le32(XSHM_CLOSED); + return err; +} + +static void xshmdev_close(struct xshm_dev *dev) +{ + pr_xshmstate(dev, "enter"); + + dev->state = XSHM_DEV_CLOSED; + *dev->cfg.rx.read = *dev->cfg.rx.write; + *dev->cfg.tx.state = cpu_to_le32(XSHM_CLOSED); + xshmdev_ipc_tx(dev); + if (dev->close_cb) + dev->close_cb(dev->driver_data); + + pr_devel("call genio_unsubscribe(%d)\n", dev->cfg.rx.xfer_bit); + genio_unsubscribe(dev->cfg.rx.xfer_bit); + pr_devel("call genio_unsubscribe(%d)\n", dev->cfg.tx.xfer_done_bit); + genio_unsubscribe(dev->cfg.tx.xfer_done_bit); +} + +int xshm_register_devices(struct xshm_dev *devs[], int devices, + const struct bin_attribute *attr) +{ + + int i, err; + + for (i = 0; i < devices; i++) { + struct xshm_dev *dev = devs[i]; + dev->state = XSHM_DEV_CLOSED; + dev->open = xshmdev_open; + dev->close = xshmdev_close; + dev->ipc_rx_release = xshmdev_ipc_rx_release; + dev->ipc_tx = xshmdev_ipc_tx; + xdev_devl(dev, "register XSHM device %s\n", + dev_name(&dev->dev)); + dev->dev.parent = parentdev; + + err = xshm_register_device(dev); + if (err) { + xdev_dbg(dev, "registration failed (%d)\n", err); + return err; + } + } + + return device_create_bin_file(parentdev, attr); +} +EXPORT_SYMBOL(xshm_register_devices); + +static void genio_caif_ready_cb(bool ready) +{ + pr_devel("enter\n"); + /* Set global variable ready_for_caif true */ + if (ready_for_caif != ready) { + ready_for_caif = ready; + xshm_caif_ready(); + } +} + +static void genio_errhandler(int errno) +{ + /* Fake CAIF_READY low to trigger modem restart */ + pr_warn("Driver reported error:%d\n", errno); + ready_for_caif = 0; + xshm_caif_ready(); +} + +struct xshm_bits { + u32 setter; + u32 getter; +}; + +static void collect_bits(struct xshm_dev *dev, void *data) +{ + struct xshm_bits *bits = data; + bits->setter |= 1 << dev->cfg.tx.xfer_bit; + bits->setter |= 1 << dev->cfg.rx.xfer_done_bit; + bits->getter |= 1 << dev->cfg.rx.xfer_bit; + bits->getter |= 1 << dev->cfg.tx.xfer_done_bit; +} + +static void handle_open(struct xshm_dev *dev, void *data) +{ + if (dev->cfg.rx.state != NULL && dev->cfg.tx.state != NULL && + *dev->cfg.rx.state == cpu_to_le32(XSHM_OPEN) && + *dev->cfg.tx.state == cpu_to_le32(XSHM_OPEN)) { + dev->state = XSHM_DEV_OPEN; + do_open(dev); + } +} + +void genio_ipc_ready_cb(void) +{ + int err; + struct xshm_bits bits = {0, 0}; + + pr_devel("enter\n"); + /* Set global variable ready_for_ipc true */ +#ifdef DEBUG + /* + * In real life read_for_ipc doesn't change, but it's + * convenient for testing. + */ + ready_for_ipc = !ready_for_ipc; +#else + ready_for_ipc = true; +#endif + + xshm_ipc_ready(); + + genio_register_errhandler(genio_errhandler); + + pr_devel("call genio_subscribe_caif_ready()\n"); + err = genio_subscribe_caif_ready(genio_caif_ready_cb); + if (err < 0) + pr_debug("genio_subscribe_caif_ready failed:%d\n", err); + + /* Collect the bit-mask for GENIO bits */ + xshm_foreach_dev(collect_bits, &bits); + pr_devel("call genio_bit_alloc(%x,%x)\n", bits.setter, bits.getter); + err = genio_bit_alloc(bits.setter, bits.getter); + if (err < 0) + pr_debug("genio_bit_alloc failed:%d\n", err); + xshm_foreach_dev(handle_open, NULL); +} +EXPORT_SYMBOL(genio_ipc_ready_cb); + +/* sysfs: ipc_ready file */ +static ssize_t ipc_ready_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", ready_for_ipc); +} + +/* sysfs: ipc_ready file */ +static ssize_t caif_ready_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", ready_for_caif); +} + +static DEVICE_ATTR(ipc_ready, S_IRUSR | S_IRUGO, ipc_ready_show, NULL); +static DEVICE_ATTR(caif_ready, S_IRUSR | S_IRUGO, caif_ready_show, NULL); + + +/* sysfs: notification on change of ipc_ready to user space */ +void xshm_ipc_ready(void) +{ + sysfs_notify(&parentdev->kobj, NULL, dev_attr_ipc_ready.attr.name); +} + +/* sysfs: notification on change of caif_ready to user space */ +void xshm_caif_ready(void) +{ + sysfs_notify(&parentdev->kobj, NULL, dev_attr_caif_ready.attr.name); +} + +static void parent_release(struct device *dev) +{ +} + +static int __init xshm_init(void) +{ + int err; + + pr_devel("Initializing\n"); + + /* Pre-calculate inactivity timeout. */ + if (xshm_inactivity_timeout != -1) { + inactivity_timeout = + xshm_inactivity_timeout * HZ / 1000; + if (inactivity_timeout == 0) + inactivity_timeout = 1; + else if (inactivity_timeout > NEXT_TIMER_MAX_DELTA) + inactivity_timeout = NEXT_TIMER_MAX_DELTA; + } else + inactivity_timeout = NEXT_TIMER_MAX_DELTA; + + spin_lock_init(&timer_lock); + init_timer(&inactivity_timer); + inactivity_timer.data = 0L; + inactivity_timer.function = inactivity_tout; + + pr_devel("call genio_init()\n"); + + parentdev = &_parentdev; + memset(parentdev, 0, sizeof(parentdev)); + dev_set_name(parentdev, "xshm"); + parentdev->release = parent_release; + + err = device_register(parentdev); + if (err) + goto err; + + err = device_create_file(parentdev, &dev_attr_ipc_ready); + if (err) + goto err_unreg; + err = device_create_file(parentdev, &dev_attr_caif_ready); + if (err) + goto err_unreg; + + return err; +err_unreg: + pr_debug("initialization failed\n"); + device_unregister(parentdev); +err: + pr_devel("call genio_exit()\n"); + return err; +} + +static void handle_close(struct xshm_dev *dev, void *data) +{ + if (dev->close_cb) + dev->close_cb(dev->driver_data); +} + +void close_devices(void) +{ + xshm_foreach_dev(handle_close, NULL); +} + +static void handle_reset(struct xshm_dev *dev, void *data) +{ + if (dev->close_cb) + dev->close_cb(dev->driver_data); + xshm_unregister_device(dev); +} + +void xshm_reset(void) +{ + xshm_foreach_dev(handle_reset, NULL); + reset_activity_tout(); + genio_reset(); +} +EXPORT_SYMBOL(xshm_reset); + +static void __exit xshm_exit(void) +{ + device_unregister(parentdev); + xshm_reset(); + genio_unsubscribe(READY_FOR_IPC_BIT); + genio_unsubscribe(READY_FOR_CAIF_BIT); +} + +module_init(xshm_init); +module_exit(xshm_exit); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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