diff options
Diffstat (limited to 'net/9p/trans_usbg.c')
| -rw-r--r-- | net/9p/trans_usbg.c | 956 |
1 files changed, 956 insertions, 0 deletions
diff --git a/net/9p/trans_usbg.c b/net/9p/trans_usbg.c new file mode 100644 index 000000000000..975b76839dca --- /dev/null +++ b/net/9p/trans_usbg.c @@ -0,0 +1,956 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * trans_usbg.c - USB peripheral usb9pfs configuration driver and transport. + * + * Copyright (C) 2024 Michael Grzeschik <m.grzeschik@pengutronix.de> + */ + +/* Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs + * transport to mount host exported filesystem via usb gadget. + */ + +/* +--------------------------+ | +--------------------------+ + * | 9PFS mounting client | | | 9PFS exporting server | + * SW | | | | | + * | (this:trans_usbg) | | |(e.g. diod or nfs-ganesha)| + * +-------------^------------+ | +-------------^------------+ + * | | | + * ------------------|------------------------------------|------------- + * | | | + * +-------------v------------+ | +-------------v------------+ + * | | | | | + * HW | USB Device Controller <---------> USB Host Controller | + * | | | | | + * +--------------------------+ | +--------------------------+ + */ + +#include <linux/cleanup.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/usb/composite.h> +#include <linux/usb/func_utils.h> + +#include <net/9p/9p.h> +#include <net/9p/client.h> +#include <net/9p/transport.h> + +#define DEFAULT_BUFLEN 16384 + +struct f_usb9pfs { + struct p9_client *client; + + /* 9p request lock for en/dequeue */ + spinlock_t lock; + + struct usb_request *in_req; + struct usb_request *out_req; + + struct usb_ep *in_ep; + struct usb_ep *out_ep; + + struct completion send; + struct completion received; + + unsigned int buflen; + + struct usb_function function; +}; + +static inline struct f_usb9pfs *func_to_usb9pfs(struct usb_function *f) +{ + return container_of(f, struct f_usb9pfs, function); +} + +struct f_usb9pfs_opts { + struct usb_function_instance func_inst; + unsigned int buflen; + + struct f_usb9pfs_dev *dev; + + /* Read/write access to configfs attributes is handled by configfs. + * + * This is to protect the data from concurrent access by read/write + * and create symlink/remove symlink. + */ + struct mutex lock; + int refcnt; +}; + +struct f_usb9pfs_dev { + struct f_usb9pfs *usb9pfs; + struct f_usb9pfs_opts *opts; + char tag[41]; + bool inuse; + + struct list_head usb9pfs_instance; +}; + +static DEFINE_MUTEX(usb9pfs_lock); +static struct list_head usbg_instance_list; + +static int usb9pfs_queue_tx(struct f_usb9pfs *usb9pfs, struct p9_req_t *p9_tx_req, + gfp_t gfp_flags) +{ + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct usb_request *req = usb9pfs->in_req; + int ret; + + if (!(p9_tx_req->tc.size % usb9pfs->in_ep->maxpacket)) + req->zero = 1; + + req->buf = p9_tx_req->tc.sdata; + req->length = p9_tx_req->tc.size; + req->context = p9_tx_req; + + dev_dbg(&cdev->gadget->dev, "%s usb9pfs send --> %d/%d, zero: %d\n", + usb9pfs->in_ep->name, req->actual, req->length, req->zero); + + ret = usb_ep_queue(usb9pfs->in_ep, req, gfp_flags); + if (ret) + req->context = NULL; + + dev_dbg(&cdev->gadget->dev, "tx submit --> %d\n", ret); + + return ret; +} + +static int usb9pfs_queue_rx(struct f_usb9pfs *usb9pfs, struct usb_request *req, + gfp_t gfp_flags) +{ + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + int ret; + + ret = usb_ep_queue(usb9pfs->out_ep, req, gfp_flags); + + dev_dbg(&cdev->gadget->dev, "rx submit --> %d\n", ret); + + return ret; +} + +static int usb9pfs_transmit(struct f_usb9pfs *usb9pfs, struct p9_req_t *p9_req) +{ + int ret = 0; + + guard(spinlock_irqsave)(&usb9pfs->lock); + + ret = usb9pfs_queue_tx(usb9pfs, p9_req, GFP_ATOMIC); + if (ret) + return ret; + + list_del(&p9_req->req_list); + + p9_req_get(p9_req); + + return ret; +} + +static void usb9pfs_tx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_usb9pfs *usb9pfs = ep->driver_data; + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct p9_req_t *p9_tx_req = req->context; + unsigned long flags; + + /* reset zero packages */ + req->zero = 0; + + if (req->status) { + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + return; + } + + dev_dbg(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + + spin_lock_irqsave(&usb9pfs->lock, flags); + WRITE_ONCE(p9_tx_req->status, REQ_STATUS_SENT); + + p9_req_put(usb9pfs->client, p9_tx_req); + + req->context = NULL; + + spin_unlock_irqrestore(&usb9pfs->lock, flags); + + complete(&usb9pfs->send); +} + +static struct p9_req_t *usb9pfs_rx_header(struct f_usb9pfs *usb9pfs, void *buf) +{ + struct p9_req_t *p9_rx_req; + struct p9_fcall rc; + int ret; + + /* start by reading header */ + rc.sdata = buf; + rc.offset = 0; + rc.capacity = P9_HDRSZ; + rc.size = P9_HDRSZ; + + p9_debug(P9_DEBUG_TRANS, "mux %p got %zu bytes\n", usb9pfs, + rc.capacity - rc.offset); + + ret = p9_parse_header(&rc, &rc.size, NULL, NULL, 0); + if (ret) { + p9_debug(P9_DEBUG_ERROR, + "error parsing header: %d\n", ret); + return NULL; + } + + p9_debug(P9_DEBUG_TRANS, + "mux %p pkt: size: %d bytes tag: %d\n", + usb9pfs, rc.size, rc.tag); + + p9_rx_req = p9_tag_lookup(usb9pfs->client, rc.tag); + if (!p9_rx_req || p9_rx_req->status != REQ_STATUS_SENT) { + p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n", rc.tag); + return NULL; + } + + if (rc.size > p9_rx_req->rc.capacity) { + p9_debug(P9_DEBUG_ERROR, + "requested packet size too big: %d for tag %d with capacity %zd\n", + rc.size, rc.tag, p9_rx_req->rc.capacity); + p9_req_put(usb9pfs->client, p9_rx_req); + return NULL; + } + + if (!p9_rx_req->rc.sdata) { + p9_debug(P9_DEBUG_ERROR, + "No recv fcall for tag %d (req %p), disconnecting!\n", + rc.tag, p9_rx_req); + p9_req_put(usb9pfs->client, p9_rx_req); + return NULL; + } + + return p9_rx_req; +} + +static void usb9pfs_rx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_usb9pfs *usb9pfs = ep->driver_data; + struct usb_composite_dev *cdev = usb9pfs->function.config->cdev; + struct p9_req_t *p9_rx_req; + + if (req->status) { + dev_err(&cdev->gadget->dev, "%s usb9pfs complete --> %d, %d/%d\n", + ep->name, req->status, req->actual, req->length); + return; + } + + p9_rx_req = usb9pfs_rx_header(usb9pfs, req->buf); + if (!p9_rx_req) + return; + + memcpy(p9_rx_req->rc.sdata, req->buf, req->actual); + + p9_rx_req->rc.size = req->actual; + + p9_client_cb(usb9pfs->client, p9_rx_req, REQ_STATUS_RCVD); + p9_req_put(usb9pfs->client, p9_rx_req); + + complete(&usb9pfs->received); +} + +static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep) +{ + int value; + + value = usb_ep_disable(ep); + if (value < 0) + dev_info(&cdev->gadget->dev, + "disable %s --> %d\n", ep->name, value); +} + +static void disable_usb9pfs(struct f_usb9pfs *usb9pfs) +{ + struct usb_composite_dev *cdev = + usb9pfs->function.config->cdev; + + if (usb9pfs->in_req) { + usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req); + usb9pfs->in_req = NULL; + } + + if (usb9pfs->out_req) { + usb_ep_free_request(usb9pfs->out_ep, usb9pfs->out_req); + usb9pfs->out_req = NULL; + } + + disable_ep(cdev, usb9pfs->in_ep); + disable_ep(cdev, usb9pfs->out_ep); + dev_dbg(&cdev->gadget->dev, "%s disabled\n", + usb9pfs->function.name); +} + +static int alloc_requests(struct usb_composite_dev *cdev, + struct f_usb9pfs *usb9pfs) +{ + int ret; + + usb9pfs->in_req = usb_ep_alloc_request(usb9pfs->in_ep, GFP_ATOMIC); + if (!usb9pfs->in_req) { + ret = -ENOENT; + goto fail; + } + + usb9pfs->out_req = alloc_ep_req(usb9pfs->out_ep, usb9pfs->buflen); + if (!usb9pfs->out_req) { + ret = -ENOENT; + goto fail_in; + } + + usb9pfs->in_req->complete = usb9pfs_tx_complete; + usb9pfs->out_req->complete = usb9pfs_rx_complete; + + /* length will be set in complete routine */ + usb9pfs->in_req->context = usb9pfs; + usb9pfs->out_req->context = usb9pfs; + + return 0; + +fail_in: + usb_ep_free_request(usb9pfs->in_ep, usb9pfs->in_req); +fail: + return ret; +} + +static int enable_endpoint(struct usb_composite_dev *cdev, + struct f_usb9pfs *usb9pfs, struct usb_ep *ep) +{ + int ret; + + ret = config_ep_by_speed(cdev->gadget, &usb9pfs->function, ep); + if (ret) + return ret; + + ret = usb_ep_enable(ep); + if (ret < 0) + return ret; + + ep->driver_data = usb9pfs; + + return 0; +} + +static int +enable_usb9pfs(struct usb_composite_dev *cdev, struct f_usb9pfs *usb9pfs) +{ + struct p9_client *client; + int ret = 0; + + ret = enable_endpoint(cdev, usb9pfs, usb9pfs->in_ep); + if (ret) + goto out; + + ret = enable_endpoint(cdev, usb9pfs, usb9pfs->out_ep); + if (ret) + goto disable_in; + + ret = alloc_requests(cdev, usb9pfs); + if (ret) + goto disable_out; + + client = usb9pfs->client; + if (client) + client->status = Connected; + + dev_dbg(&cdev->gadget->dev, "%s enabled\n", usb9pfs->function.name); + return 0; + +disable_out: + usb_ep_disable(usb9pfs->out_ep); +disable_in: + usb_ep_disable(usb9pfs->in_ep); +out: + return ret; +} + +static int p9_usbg_create(struct p9_client *client, const char *devname, char *args) +{ + struct f_usb9pfs_dev *dev; + struct f_usb9pfs *usb9pfs; + int ret = -ENOENT; + int found = 0; + + if (!devname) + return -EINVAL; + + guard(mutex)(&usb9pfs_lock); + + list_for_each_entry(dev, &usbg_instance_list, usb9pfs_instance) { + if (!strncmp(devname, dev->tag, strlen(devname))) { + if (!dev->inuse) { + dev->inuse = true; + found = 1; + break; + } + ret = -EBUSY; + break; + } + } + + if (!found) { + pr_err("no channels available for device %s\n", devname); + return ret; + } + + usb9pfs = dev->usb9pfs; + if (!usb9pfs) + return -EINVAL; + + client->trans = (void *)usb9pfs; + if (!usb9pfs->in_req) + client->status = Disconnected; + else + client->status = Connected; + usb9pfs->client = client; + + client->trans_mod->maxsize = usb9pfs->buflen; + + complete(&usb9pfs->received); + + return 0; +} + +static void usb9pfs_clear_tx(struct f_usb9pfs *usb9pfs) +{ + struct p9_req_t *req; + + guard(spinlock_irqsave)(&usb9pfs->lock); + + req = usb9pfs->in_req->context; + if (!req) + return; + + if (!req->t_err) + req->t_err = -ECONNRESET; + + p9_client_cb(usb9pfs->client, req, REQ_STATUS_ERROR); +} + +static void p9_usbg_close(struct p9_client *client) +{ + struct f_usb9pfs *usb9pfs; + struct f_usb9pfs_dev *dev; + struct f_usb9pfs_opts *opts; + + if (!client) + return; + + usb9pfs = client->trans; + if (!usb9pfs) + return; + + client->status = Disconnected; + + usb9pfs_clear_tx(usb9pfs); + + opts = container_of(usb9pfs->function.fi, + struct f_usb9pfs_opts, func_inst); + + dev = opts->dev; + + mutex_lock(&usb9pfs_lock); + dev->inuse = false; + mutex_unlock(&usb9pfs_lock); +} + +static int p9_usbg_request(struct p9_client *client, struct p9_req_t *p9_req) +{ + struct f_usb9pfs *usb9pfs = client->trans; + int ret; + + if (client->status != Connected) + return -EBUSY; + + ret = wait_for_completion_killable(&usb9pfs->received); + if (ret) + return ret; + + ret = usb9pfs_transmit(usb9pfs, p9_req); + if (ret) + return ret; + + ret = wait_for_completion_killable(&usb9pfs->send); + if (ret) + return ret; + + return usb9pfs_queue_rx(usb9pfs, usb9pfs->out_req, GFP_ATOMIC); +} + +static int p9_usbg_cancel(struct p9_client *client, struct p9_req_t *req) +{ + struct f_usb9pfs *usb9pfs = client->trans; + int ret = 1; + + p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req); + + guard(spinlock_irqsave)(&usb9pfs->lock); + + if (req->status == REQ_STATUS_UNSENT) { + list_del(&req->req_list); + WRITE_ONCE(req->status, REQ_STATUS_FLSHD); + p9_req_put(client, req); + ret = 0; + } + + return ret; +} + +static struct p9_trans_module p9_usbg_trans = { + .name = "usbg", + .create = p9_usbg_create, + .close = p9_usbg_close, + .request = p9_usbg_request, + .cancel = p9_usbg_cancel, + .owner = THIS_MODULE, +}; + +/*-------------------------------------------------------------------------*/ + +#define USB_PROTOCOL_9PFS 0x09 + +static struct usb_interface_descriptor usb9pfs_intf = { + .bLength = sizeof(usb9pfs_intf), + .bDescriptorType = USB_DT_INTERFACE, + + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_VENDOR_SPEC, + .bInterfaceSubClass = USB_SUBCLASS_VENDOR_SPEC, + .bInterfaceProtocol = USB_PROTOCOL_9PFS, + + /* .iInterface = DYNAMIC */ +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor fs_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_endpoint_descriptor fs_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_descriptor_header *fs_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&fs_usb9pfs_sink_desc, + (struct usb_descriptor_header *)&fs_usb9pfs_source_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor hs_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_endpoint_descriptor hs_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_descriptor_header *hs_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&hs_usb9pfs_source_desc, + (struct usb_descriptor_header *)&hs_usb9pfs_sink_desc, + NULL, +}; + +/* super speed support: */ + +static struct usb_endpoint_descriptor ss_usb9pfs_source_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_source_comp_desc = { + .bLength = USB_DT_SS_EP_COMP_SIZE, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + .bMaxBurst = 0, + .bmAttributes = 0, + .wBytesPerInterval = 0, +}; + +static struct usb_endpoint_descriptor ss_usb9pfs_sink_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_ss_ep_comp_descriptor ss_usb9pfs_sink_comp_desc = { + .bLength = USB_DT_SS_EP_COMP_SIZE, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + .bMaxBurst = 0, + .bmAttributes = 0, + .wBytesPerInterval = 0, +}; + +static struct usb_descriptor_header *ss_usb9pfs_descs[] = { + (struct usb_descriptor_header *)&usb9pfs_intf, + (struct usb_descriptor_header *)&ss_usb9pfs_source_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_source_comp_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_sink_desc, + (struct usb_descriptor_header *)&ss_usb9pfs_sink_comp_desc, + NULL, +}; + +/* function-specific strings: */ +static struct usb_string strings_usb9pfs[] = { + [0].s = "usb9pfs input to output", + { } /* end of list */ +}; + +static struct usb_gadget_strings stringtab_usb9pfs = { + .language = 0x0409, /* en-us */ + .strings = strings_usb9pfs, +}; + +static struct usb_gadget_strings *usb9pfs_strings[] = { + &stringtab_usb9pfs, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +static int usb9pfs_func_bind(struct usb_configuration *c, + struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct f_usb9pfs_opts *opts; + struct usb_composite_dev *cdev = c->cdev; + int ret; + int id; + + /* allocate interface ID(s) */ + id = usb_interface_id(c, f); + if (id < 0) + return id; + usb9pfs_intf.bInterfaceNumber = id; + + id = usb_string_id(cdev); + if (id < 0) + return id; + strings_usb9pfs[0].id = id; + usb9pfs_intf.iInterface = id; + + /* allocate endpoints */ + usb9pfs->in_ep = usb_ep_autoconfig(cdev->gadget, + &fs_usb9pfs_source_desc); + if (!usb9pfs->in_ep) + goto autoconf_fail; + + usb9pfs->out_ep = usb_ep_autoconfig(cdev->gadget, + &fs_usb9pfs_sink_desc); + if (!usb9pfs->out_ep) + goto autoconf_fail; + + /* support high speed hardware */ + hs_usb9pfs_source_desc.bEndpointAddress = + fs_usb9pfs_source_desc.bEndpointAddress; + hs_usb9pfs_sink_desc.bEndpointAddress = + fs_usb9pfs_sink_desc.bEndpointAddress; + + /* support super speed hardware */ + ss_usb9pfs_source_desc.bEndpointAddress = + fs_usb9pfs_source_desc.bEndpointAddress; + ss_usb9pfs_sink_desc.bEndpointAddress = + fs_usb9pfs_sink_desc.bEndpointAddress; + + ret = usb_assign_descriptors(f, fs_usb9pfs_descs, hs_usb9pfs_descs, + ss_usb9pfs_descs, ss_usb9pfs_descs); + if (ret) + return ret; + + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst); + opts->dev->usb9pfs = usb9pfs; + + dev_dbg(&cdev->gadget->dev, "%s speed %s: IN/%s, OUT/%s\n", + (gadget_is_superspeed(c->cdev->gadget) ? "super" : + (gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full")), + f->name, usb9pfs->in_ep->name, usb9pfs->out_ep->name); + + return 0; + +autoconf_fail: + ERROR(cdev, "%s: can't autoconfigure on %s\n", + f->name, cdev->gadget->name); + return -ENODEV; +} + +static void usb9pfs_func_unbind(struct usb_configuration *c, + struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + + disable_usb9pfs(usb9pfs); +} + +static void usb9pfs_free_func(struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct f_usb9pfs_opts *opts; + + kfree(usb9pfs); + + opts = container_of(f->fi, struct f_usb9pfs_opts, func_inst); + + mutex_lock(&opts->lock); + opts->refcnt--; + mutex_unlock(&opts->lock); + + usb_free_all_descriptors(f); +} + +static int usb9pfs_set_alt(struct usb_function *f, + unsigned int intf, unsigned int alt) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + struct usb_composite_dev *cdev = f->config->cdev; + + return enable_usb9pfs(cdev, usb9pfs); +} + +static void usb9pfs_disable(struct usb_function *f) +{ + struct f_usb9pfs *usb9pfs = func_to_usb9pfs(f); + + usb9pfs_clear_tx(usb9pfs); +} + +static struct usb_function *usb9pfs_alloc(struct usb_function_instance *fi) +{ + struct f_usb9pfs_opts *usb9pfs_opts; + struct f_usb9pfs *usb9pfs; + + usb9pfs = kzalloc(sizeof(*usb9pfs), GFP_KERNEL); + if (!usb9pfs) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&usb9pfs->lock); + + init_completion(&usb9pfs->send); + init_completion(&usb9pfs->received); + + usb9pfs_opts = container_of(fi, struct f_usb9pfs_opts, func_inst); + + mutex_lock(&usb9pfs_opts->lock); + usb9pfs_opts->refcnt++; + mutex_unlock(&usb9pfs_opts->lock); + + usb9pfs->buflen = usb9pfs_opts->buflen; + + usb9pfs->function.name = "usb9pfs"; + usb9pfs->function.bind = usb9pfs_func_bind; + usb9pfs->function.unbind = usb9pfs_func_unbind; + usb9pfs->function.set_alt = usb9pfs_set_alt; + usb9pfs->function.disable = usb9pfs_disable; + usb9pfs->function.strings = usb9pfs_strings; + + usb9pfs->function.free_func = usb9pfs_free_func; + + return &usb9pfs->function; +} + +static inline struct f_usb9pfs_opts *to_f_usb9pfs_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_usb9pfs_opts, + func_inst.group); +} + +static inline struct f_usb9pfs_opts *fi_to_f_usb9pfs_opts(struct usb_function_instance *fi) +{ + return container_of(fi, struct f_usb9pfs_opts, func_inst); +} + +static void usb9pfs_attr_release(struct config_item *item) +{ + struct f_usb9pfs_opts *usb9pfs_opts = to_f_usb9pfs_opts(item); + + usb_put_function_instance(&usb9pfs_opts->func_inst); +} + +static struct configfs_item_operations usb9pfs_item_ops = { + .release = usb9pfs_attr_release, +}; + +static ssize_t f_usb9pfs_opts_buflen_show(struct config_item *item, char *page) +{ + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item); + int ret; + + mutex_lock(&opts->lock); + ret = sysfs_emit(page, "%d\n", opts->buflen); + mutex_unlock(&opts->lock); + + return ret; +} + +static ssize_t f_usb9pfs_opts_buflen_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_usb9pfs_opts *opts = to_f_usb9pfs_opts(item); + int ret; + u32 num; + + guard(mutex)(&opts->lock); + + if (opts->refcnt) + return -EBUSY; + + ret = kstrtou32(page, 0, &num); + if (ret) + return ret; + + opts->buflen = num; + + return len; +} + +CONFIGFS_ATTR(f_usb9pfs_opts_, buflen); + +static struct configfs_attribute *usb9pfs_attrs[] = { + &f_usb9pfs_opts_attr_buflen, + NULL, +}; + +static const struct config_item_type usb9pfs_func_type = { + .ct_item_ops = &usb9pfs_item_ops, + .ct_attrs = usb9pfs_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct f_usb9pfs_dev *_usb9pfs_do_find_dev(const char *tag) +{ + struct f_usb9pfs_dev *usb9pfs_dev; + + if (!tag) + return NULL; + + list_for_each_entry(usb9pfs_dev, &usbg_instance_list, usb9pfs_instance) { + if (strcmp(usb9pfs_dev->tag, tag) == 0) + return usb9pfs_dev; + } + + return NULL; +} + +static int usb9pfs_tag_instance(struct f_usb9pfs_dev *dev, const char *tag) +{ + struct f_usb9pfs_dev *existing; + int ret = 0; + + guard(mutex)(&usb9pfs_lock); + + existing = _usb9pfs_do_find_dev(tag); + if (!existing) + strscpy(dev->tag, tag, ARRAY_SIZE(dev->tag)); + else if (existing != dev) + ret = -EBUSY; + + return ret; +} + +static int usb9pfs_set_inst_tag(struct usb_function_instance *fi, const char *tag) +{ + if (strlen(tag) >= sizeof_field(struct f_usb9pfs_dev, tag)) + return -ENAMETOOLONG; + return usb9pfs_tag_instance(fi_to_f_usb9pfs_opts(fi)->dev, tag); +} + +static void usb9pfs_free_instance(struct usb_function_instance *fi) +{ + struct f_usb9pfs_opts *usb9pfs_opts = + container_of(fi, struct f_usb9pfs_opts, func_inst); + struct f_usb9pfs_dev *dev = usb9pfs_opts->dev; + + mutex_lock(&usb9pfs_lock); + list_del(&dev->usb9pfs_instance); + mutex_unlock(&usb9pfs_lock); + + kfree(usb9pfs_opts); +} + +static struct usb_function_instance *usb9pfs_alloc_instance(void) +{ + struct f_usb9pfs_opts *usb9pfs_opts; + struct f_usb9pfs_dev *dev; + + usb9pfs_opts = kzalloc(sizeof(*usb9pfs_opts), GFP_KERNEL); + if (!usb9pfs_opts) + return ERR_PTR(-ENOMEM); + + mutex_init(&usb9pfs_opts->lock); + + usb9pfs_opts->func_inst.set_inst_name = usb9pfs_set_inst_tag; + usb9pfs_opts->func_inst.free_func_inst = usb9pfs_free_instance; + + usb9pfs_opts->buflen = DEFAULT_BUFLEN; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (IS_ERR(dev)) { + kfree(usb9pfs_opts); + return ERR_CAST(dev); + } + + usb9pfs_opts->dev = dev; + dev->opts = usb9pfs_opts; + + config_group_init_type_name(&usb9pfs_opts->func_inst.group, "", + &usb9pfs_func_type); + + mutex_lock(&usb9pfs_lock); + list_add_tail(&dev->usb9pfs_instance, &usbg_instance_list); + mutex_unlock(&usb9pfs_lock); + + return &usb9pfs_opts->func_inst; +} +DECLARE_USB_FUNCTION(usb9pfs, usb9pfs_alloc_instance, usb9pfs_alloc); + +static int __init usb9pfs_modinit(void) +{ + int ret; + + INIT_LIST_HEAD(&usbg_instance_list); + + ret = usb_function_register(&usb9pfsusb_func); + if (!ret) + v9fs_register_trans(&p9_usbg_trans); + + return ret; +} + +static void __exit usb9pfs_modexit(void) +{ + usb_function_unregister(&usb9pfsusb_func); + v9fs_unregister_trans(&p9_usbg_trans); +} + +module_init(usb9pfs_modinit); +module_exit(usb9pfs_modexit); + +MODULE_ALIAS_9P("usbg"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("USB gadget 9pfs transport"); +MODULE_AUTHOR("Michael Grzeschik"); |