Changes in 4.9.204 net/mlx4_en: fix mlx4 ethtool -N insertion net: rtnetlink: prevent underflows in do_setvfinfo() sfc: Only cancel the PPS workqueue if it exists net/mlx5e: Fix set vf link state error flow net/sched: act_pedit: fix WARN() in the traffic path gpio: max77620: Fixup debounce delays tools: gpio: Correctly add make dependencies for gpio_utils Revert "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()" mm/ksm.c: don't WARN if page is still mapped in remove_stable_node() platform/x86: asus-nb-wmi: Support ALS on the Zenbook UX430UQ platform/x86: asus-wmi: Only Tell EC the OS will handle display hotkeys from asus_nb_wmi mwifiex: Fix NL80211_TX_POWER_LIMITED ALSA: isight: fix leak of reference to firewire unit in error path of .probe callback printk: fix integer overflow in setup_log_buf() gfs2: Fix marking bitmaps non-full synclink_gt(): fix compat_ioctl() powerpc: Fix signedness bug in update_flash_db() powerpc/eeh: Fix use of EEH_PE_KEEP on wrong field brcmsmac: AP mode: update beacon when TIM changes ath10k: allocate small size dma memory in ath10k_pci_diag_write_mem spi: sh-msiof: fix deferred probing mmc: mediatek: fix cannot receive new request when msdc_cmd_is_ready fail btrfs: handle error of get_old_root gsmi: Fix bug in append_to_eventlog sysfs handler misc: mic: fix a DMA pool free failure m68k: fix command-line parsing when passed from u-boot amiflop: clean up on errors during setup scsi: ips: fix missing break in switch KVM/x86: Fix invvpid and invept register operand size in 64-bit mode scsi: isci: Use proper enumerated type in atapi_d2h_reg_frame_handler scsi: isci: Change sci_controller_start_task's return type to sci_status scsi: iscsi_tcp: Explicitly cast param in iscsi_sw_tcp_host_get_param clk: mmp2: fix the clock id for sdh2_clk and sdh3_clk ASoC: tegra_sgtl5000: fix device_node refcounting scsi: dc395x: fix dma API usage in srb_done scsi: dc395x: fix DMA API usage in sg_update_list net: fix warning in af_unix net: ena: Fix Kconfig dependency on X86 xfs: fix use-after-free race in xfs_buf_rele kprobes, x86/ptrace.h: Make regs_get_kernel_stack_nth() not fault on bad stack ALSA: i2c/cs8427: Fix int to char conversion macintosh/windfarm_smu_sat: Fix debug output USB: misc: appledisplay: fix backlight update_status return code usbip: tools: fix atoi() on non-null terminated string SUNRPC: Fix a compile warning for cmpxchg64() sunrpc: safely reallow resvport min/max inversion atm: zatm: Fix empty body Clang warnings s390/perf: Return error when debug_register fails spi: omap2-mcspi: Set FIFO DMA trigger level to word length sparc: Fix parport build warnings. ceph: fix dentry leak in ceph_readdir_prepopulate rtc: s35390a: Change buf's type to u8 in s35390a_init f2fs: fix to spread clear_cold_data() mISDN: Fix type of switch control variable in ctrl_teimanager qlcnic: fix a return in qlcnic_dcb_get_capability() net: ethernet: ti: cpsw: unsync mcast entries while switch promisc mode mfd: arizona: Correct calling of runtime_put_sync mfd: mc13xxx-core: Fix PMIC shutdown when reading ADC values mfd: max8997: Enale irq-wakeup unconditionally selftests/ftrace: Fix to test kprobe $comm arg only if available thermal: rcar_thermal: Prevent hardware access during system suspend powerpc/process: Fix flush_all_to_thread for SPE sparc64: Rework xchg() definition to avoid warnings. fs/ocfs2/dlm/dlmdebug.c: fix a sleep-in-atomic-context bug in dlm_print_one_mle() mm/page-writeback.c: fix range_cyclic writeback vs writepages deadlock macsec: update operstate when lower device changes macsec: let the administrator set UP state even if lowerdev is down um: Make line/tty semantics use true write IRQ linux/bitmap.h: handle constant zero-size bitmaps correctly linux/bitmap.h: fix type of nbits in bitmap_shift_right() hfsplus: fix BUG on bnode parent update hfs: fix BUG on bnode parent update hfsplus: prevent btree data loss on ENOSPC hfs: prevent btree data loss on ENOSPC hfsplus: fix return value of hfsplus_get_block() hfs: fix return value of hfs_get_block() hfsplus: update timestamps on truncate() hfs: update timestamp on truncate() fs/hfs/extent.c: fix array out of bounds read of array extent mm/memory_hotplug: make add_memory() take the device_hotplug_lock igb: shorten maximum PHC timecounter update interval ntb_netdev: fix sleep time mismatch ntb: intel: fix return value for ndev_vec_mask() arm64: makefile fix build of .i file in external module case ocfs2: don't put and assigning null to bh allocated outside ocfs2: fix clusters leak in ocfs2_defrag_extent() net: do not abort bulk send on BQL status sched/fair: Don't increase sd->balance_interval on newidle balance audit: print empty EXECVE args wlcore: Fix the return value in case of error in 'wlcore_vendor_cmd_smart_config_start()' rtl8xxxu: Fix missing break in switch brcmsmac: never log "tid x is not agg'able" by default wireless: airo: potential buffer overflow in sprintf() rtlwifi: rtl8192de: Fix misleading REG_MCUFWDL information scsi: mpt3sas: Fix Sync cache command failure during driver unload scsi: mpt3sas: Fix driver modifying persistent data in Manufacturing page11 scsi: megaraid_sas: Fix msleep granularity scsi: lpfc: fcoe: Fix link down issue after 1000+ link bounces dlm: fix invalid free dlm: don't leak kernel pointer to userspace ACPICA: Use %d for signed int print formatting instead of %u net: bcmgenet: return correct value 'ret' from bcmgenet_power_down sock: Reset dst when changing sk_mark via setsockopt pinctrl: qcom: spmi-gpio: fix gpio-hog related boot issues pinctrl: lpc18xx: Use define directive for PIN_CONFIG_GPIO_PIN_INT pinctrl: zynq: Use define directive for PIN_CONFIG_IO_STANDARD PCI: keystone: Use quirk to limit MRRS for K2G spi: omap2-mcspi: Fix DMA and FIFO event trigger size mismatch mm/memory_hotplug: Do not unlock when fails to take the device_hotplug_lock Bluetooth: Fix invalid-free in bcsp_close() KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved ath9k_hw: fix uninitialized variable data dm: use blk_set_queue_dying() in __dm_destroy() arm64: fix for bad_mode() handler to always result in panic cpufreq: Skip cpufreq resume if it's not suspended ocfs2: remove ocfs2_is_o2cb_active() ARM: 8904/1: skip nomap memblocks while finding the lowmem/highmem boundary ARC: perf: Accommodate big-endian CPU x86/insn: Fix awk regexp warnings x86/speculation: Fix incorrect MDS/TAA mitigation status x86/speculation: Fix redundant MDS mitigation message nfc: port100: handle command failure cleanly l2tp: don't use l2tp_tunnel_find() in l2tp_ip and l2tp_ip6 media: vivid: Set vid_cap_streaming and vid_out_streaming to true media: vivid: Fix wrong locking that causes race conditions on streaming stop media: usbvision: Fix races among open, close, and disconnect cpufreq: Add NULL checks to show() and store() methods of cpufreq media: uvcvideo: Fix error path in control parsing failure media: b2c2-flexcop-usb: add sanity checking media: cxusb: detect cxusb_ctrl_msg error in query media: imon: invalid dereference in imon_touch_event virtio_console: reset on out of memory virtio_console: don't tie bufs to a vq virtio_console: allocate inbufs in add_port() only if it is needed virtio_ring: fix return code on DMA mapping fails virtio_console: fix uninitialized variable use virtio_console: drop custom control queue cleanup virtio_console: move removal code usbip: tools: fix fd leakage in the function of read_attr_usbip_status usb-serial: cp201x: support Mark-10 digital force gauge USB: chaoskey: fix error case of a timeout appledisplay: fix error handling in the scheduled work USB: serial: mos7840: add USB ID to support Moxa UPort 2210 USB: serial: mos7720: fix remote wakeup USB: serial: mos7840: fix remote wakeup USB: serial: option: add support for DW5821e with eSIM support USB: serial: option: add support for Foxconn T77W968 LTE modules staging: comedi: usbduxfast: usbduxfast_ai_cmdtest rounding error powerpc/64s: support nospectre_v2 cmdline option powerpc/book3s64: Fix link stack flush on context switch KVM: PPC: Book3S HV: Flush link stack on guest exit to host kernel Linux 4.9.204 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
613 lines
14 KiB
C
613 lines
14 KiB
C
/*
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* chaoskey - driver for ChaosKey device from Altus Metrum.
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*
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* This device provides true random numbers using a noise source based
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* on a reverse-biased p-n junction in avalanche breakdown. More
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* details can be found at http://chaoskey.org
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*
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* The driver connects to the kernel hardware RNG interface to provide
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* entropy for /dev/random and other kernel activities. It also offers
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* a separate /dev/ entry to allow for direct access to the random
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* bit stream.
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*
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* Copyright © 2015 Keith Packard <keithp@keithp.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/usb.h>
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#include <linux/wait.h>
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#include <linux/hw_random.h>
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#include <linux/mutex.h>
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#include <linux/uaccess.h>
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static struct usb_driver chaoskey_driver;
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static struct usb_class_driver chaoskey_class;
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static int chaoskey_rng_read(struct hwrng *rng, void *data,
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size_t max, bool wait);
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#define usb_dbg(usb_if, format, arg...) \
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dev_dbg(&(usb_if)->dev, format, ## arg)
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#define usb_err(usb_if, format, arg...) \
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dev_err(&(usb_if)->dev, format, ## arg)
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/* Version Information */
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#define DRIVER_VERSION "v0.1"
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#define DRIVER_AUTHOR "Keith Packard, keithp@keithp.com"
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#define DRIVER_DESC "Altus Metrum ChaosKey driver"
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#define DRIVER_SHORT "chaoskey"
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MODULE_VERSION(DRIVER_VERSION);
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MODULE_AUTHOR(DRIVER_AUTHOR);
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MODULE_DESCRIPTION(DRIVER_DESC);
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MODULE_LICENSE("GPL");
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#define CHAOSKEY_VENDOR_ID 0x1d50 /* OpenMoko */
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#define CHAOSKEY_PRODUCT_ID 0x60c6 /* ChaosKey */
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#define ALEA_VENDOR_ID 0x12d8 /* Araneus */
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#define ALEA_PRODUCT_ID 0x0001 /* Alea I */
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#define CHAOSKEY_BUF_LEN 64 /* max size of USB full speed packet */
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#define NAK_TIMEOUT (HZ) /* normal stall/wait timeout */
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#define ALEA_FIRST_TIMEOUT (HZ*3) /* first stall/wait timeout for Alea */
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#ifdef CONFIG_USB_DYNAMIC_MINORS
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#define USB_CHAOSKEY_MINOR_BASE 0
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#else
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/* IOWARRIOR_MINOR_BASE + 16, not official yet */
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#define USB_CHAOSKEY_MINOR_BASE 224
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#endif
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static const struct usb_device_id chaoskey_table[] = {
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{ USB_DEVICE(CHAOSKEY_VENDOR_ID, CHAOSKEY_PRODUCT_ID) },
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{ USB_DEVICE(ALEA_VENDOR_ID, ALEA_PRODUCT_ID) },
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{ },
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};
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MODULE_DEVICE_TABLE(usb, chaoskey_table);
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static void chaos_read_callback(struct urb *urb);
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/* Driver-local specific stuff */
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struct chaoskey {
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struct usb_interface *interface;
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char in_ep;
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struct mutex lock;
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struct mutex rng_lock;
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int open; /* open count */
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bool present; /* device not disconnected */
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bool reading; /* ongoing IO */
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bool reads_started; /* track first read for Alea */
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int size; /* size of buf */
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int valid; /* bytes of buf read */
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int used; /* bytes of buf consumed */
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char *name; /* product + serial */
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struct hwrng hwrng; /* Embedded struct for hwrng */
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int hwrng_registered; /* registered with hwrng API */
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wait_queue_head_t wait_q; /* for timeouts */
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struct urb *urb; /* for performing IO */
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char *buf;
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};
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static void chaoskey_free(struct chaoskey *dev)
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{
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if (dev) {
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usb_dbg(dev->interface, "free");
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usb_free_urb(dev->urb);
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kfree(dev->name);
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kfree(dev->buf);
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usb_put_intf(dev->interface);
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kfree(dev);
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}
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}
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static int chaoskey_probe(struct usb_interface *interface,
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const struct usb_device_id *id)
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{
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struct usb_device *udev = interface_to_usbdev(interface);
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struct usb_host_interface *altsetting = interface->cur_altsetting;
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int i;
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int in_ep = -1;
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struct chaoskey *dev;
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int result = -ENOMEM;
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int size;
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usb_dbg(interface, "probe %s-%s", udev->product, udev->serial);
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/* Find the first bulk IN endpoint and its packet size */
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for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
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if (usb_endpoint_is_bulk_in(&altsetting->endpoint[i].desc)) {
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in_ep = usb_endpoint_num(&altsetting->endpoint[i].desc);
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size = usb_endpoint_maxp(&altsetting->endpoint[i].desc);
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break;
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}
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}
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/* Validate endpoint and size */
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if (in_ep == -1) {
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usb_dbg(interface, "no IN endpoint found");
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return -ENODEV;
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}
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if (size <= 0) {
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usb_dbg(interface, "invalid size (%d)", size);
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return -ENODEV;
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}
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if (size > CHAOSKEY_BUF_LEN) {
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usb_dbg(interface, "size reduced from %d to %d\n",
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size, CHAOSKEY_BUF_LEN);
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size = CHAOSKEY_BUF_LEN;
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}
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/* Looks good, allocate and initialize */
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dev = kzalloc(sizeof(struct chaoskey), GFP_KERNEL);
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if (dev == NULL)
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goto out;
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dev->interface = usb_get_intf(interface);
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dev->buf = kmalloc(size, GFP_KERNEL);
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if (dev->buf == NULL)
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goto out;
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dev->urb = usb_alloc_urb(0, GFP_KERNEL);
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if (!dev->urb)
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goto out;
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usb_fill_bulk_urb(dev->urb,
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udev,
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usb_rcvbulkpipe(udev, in_ep),
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dev->buf,
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size,
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chaos_read_callback,
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dev);
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/* Construct a name using the product and serial values. Each
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* device needs a unique name for the hwrng code
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*/
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if (udev->product && udev->serial) {
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dev->name = kmalloc(strlen(udev->product) + 1 +
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strlen(udev->serial) + 1, GFP_KERNEL);
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if (dev->name == NULL)
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goto out;
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strcpy(dev->name, udev->product);
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strcat(dev->name, "-");
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strcat(dev->name, udev->serial);
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}
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dev->in_ep = in_ep;
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if (le16_to_cpu(udev->descriptor.idVendor) != ALEA_VENDOR_ID)
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dev->reads_started = 1;
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dev->size = size;
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dev->present = 1;
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init_waitqueue_head(&dev->wait_q);
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mutex_init(&dev->lock);
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mutex_init(&dev->rng_lock);
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usb_set_intfdata(interface, dev);
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result = usb_register_dev(interface, &chaoskey_class);
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if (result) {
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usb_err(interface, "Unable to allocate minor number.");
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goto out;
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}
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dev->hwrng.name = dev->name ? dev->name : chaoskey_driver.name;
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dev->hwrng.read = chaoskey_rng_read;
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/* Set the 'quality' metric. Quality is measured in units of
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* 1/1024's of a bit ("mills"). This should be set to 1024,
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* but there is a bug in the hwrng core which masks it with
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* 1023.
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*
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* The patch that has been merged to the crypto development
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* tree for that bug limits the value to 1024 at most, so by
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* setting this to 1024 + 1023, we get 1023 before the fix is
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* merged and 1024 afterwards. We'll patch this driver once
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* both bits of code are in the same tree.
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*/
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dev->hwrng.quality = 1024 + 1023;
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dev->hwrng_registered = (hwrng_register(&dev->hwrng) == 0);
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if (!dev->hwrng_registered)
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usb_err(interface, "Unable to register with hwrng");
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usb_enable_autosuspend(udev);
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usb_dbg(interface, "chaoskey probe success, size %d", dev->size);
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return 0;
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out:
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usb_set_intfdata(interface, NULL);
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chaoskey_free(dev);
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return result;
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}
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static void chaoskey_disconnect(struct usb_interface *interface)
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{
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struct chaoskey *dev;
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usb_dbg(interface, "disconnect");
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dev = usb_get_intfdata(interface);
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if (!dev) {
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usb_dbg(interface, "disconnect failed - no dev");
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return;
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}
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if (dev->hwrng_registered)
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hwrng_unregister(&dev->hwrng);
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usb_deregister_dev(interface, &chaoskey_class);
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usb_set_intfdata(interface, NULL);
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mutex_lock(&dev->lock);
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dev->present = 0;
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usb_poison_urb(dev->urb);
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if (!dev->open) {
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mutex_unlock(&dev->lock);
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chaoskey_free(dev);
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} else
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mutex_unlock(&dev->lock);
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usb_dbg(interface, "disconnect done");
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}
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static int chaoskey_open(struct inode *inode, struct file *file)
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{
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struct chaoskey *dev;
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struct usb_interface *interface;
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/* get the interface from minor number and driver information */
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interface = usb_find_interface(&chaoskey_driver, iminor(inode));
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if (!interface)
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return -ENODEV;
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usb_dbg(interface, "open");
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dev = usb_get_intfdata(interface);
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if (!dev) {
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usb_dbg(interface, "open (dev)");
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return -ENODEV;
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}
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file->private_data = dev;
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mutex_lock(&dev->lock);
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++dev->open;
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mutex_unlock(&dev->lock);
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usb_dbg(interface, "open success");
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return 0;
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}
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static int chaoskey_release(struct inode *inode, struct file *file)
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{
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struct chaoskey *dev = file->private_data;
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struct usb_interface *interface;
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if (dev == NULL)
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return -ENODEV;
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interface = dev->interface;
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usb_dbg(interface, "release");
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mutex_lock(&dev->lock);
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usb_dbg(interface, "open count at release is %d", dev->open);
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if (dev->open <= 0) {
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usb_dbg(interface, "invalid open count (%d)", dev->open);
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mutex_unlock(&dev->lock);
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return -ENODEV;
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}
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--dev->open;
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if (!dev->present) {
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if (dev->open == 0) {
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mutex_unlock(&dev->lock);
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chaoskey_free(dev);
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} else
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mutex_unlock(&dev->lock);
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} else
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mutex_unlock(&dev->lock);
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usb_dbg(interface, "release success");
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return 0;
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}
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static void chaos_read_callback(struct urb *urb)
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{
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struct chaoskey *dev = urb->context;
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int status = urb->status;
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usb_dbg(dev->interface, "callback status (%d)", status);
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if (status == 0)
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dev->valid = urb->actual_length;
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else
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dev->valid = 0;
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dev->used = 0;
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/* must be seen first before validity is announced */
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smp_wmb();
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dev->reading = false;
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wake_up(&dev->wait_q);
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}
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/* Fill the buffer. Called with dev->lock held
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*/
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static int _chaoskey_fill(struct chaoskey *dev)
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{
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DEFINE_WAIT(wait);
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int result;
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bool started;
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usb_dbg(dev->interface, "fill");
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/* Return immediately if someone called before the buffer was
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* empty */
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if (dev->valid != dev->used) {
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usb_dbg(dev->interface, "not empty yet (valid %d used %d)",
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dev->valid, dev->used);
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return 0;
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}
|
|
|
|
/* Bail if the device has been removed */
|
|
if (!dev->present) {
|
|
usb_dbg(dev->interface, "device not present");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/* Make sure the device is awake */
|
|
result = usb_autopm_get_interface(dev->interface);
|
|
if (result) {
|
|
usb_dbg(dev->interface, "wakeup failed (result %d)", result);
|
|
return result;
|
|
}
|
|
|
|
dev->reading = true;
|
|
result = usb_submit_urb(dev->urb, GFP_KERNEL);
|
|
if (result < 0) {
|
|
result = usb_translate_errors(result);
|
|
dev->reading = false;
|
|
goto out;
|
|
}
|
|
|
|
/* The first read on the Alea takes a little under 2 seconds.
|
|
* Reads after the first read take only a few microseconds
|
|
* though. Presumably the entropy-generating circuit needs
|
|
* time to ramp up. So, we wait longer on the first read.
|
|
*/
|
|
started = dev->reads_started;
|
|
dev->reads_started = true;
|
|
result = wait_event_interruptible_timeout(
|
|
dev->wait_q,
|
|
!dev->reading,
|
|
(started ? NAK_TIMEOUT : ALEA_FIRST_TIMEOUT) );
|
|
|
|
if (result < 0) {
|
|
usb_kill_urb(dev->urb);
|
|
goto out;
|
|
}
|
|
|
|
if (result == 0) {
|
|
result = -ETIMEDOUT;
|
|
usb_kill_urb(dev->urb);
|
|
} else {
|
|
result = dev->valid;
|
|
}
|
|
out:
|
|
/* Let the device go back to sleep eventually */
|
|
usb_autopm_put_interface(dev->interface);
|
|
|
|
usb_dbg(dev->interface, "read %d bytes", dev->valid);
|
|
|
|
return result;
|
|
}
|
|
|
|
static ssize_t chaoskey_read(struct file *file,
|
|
char __user *buffer,
|
|
size_t count,
|
|
loff_t *ppos)
|
|
{
|
|
struct chaoskey *dev;
|
|
ssize_t read_count = 0;
|
|
int this_time;
|
|
int result = 0;
|
|
unsigned long remain;
|
|
|
|
dev = file->private_data;
|
|
|
|
if (dev == NULL || !dev->present)
|
|
return -ENODEV;
|
|
|
|
usb_dbg(dev->interface, "read %zu", count);
|
|
|
|
while (count > 0) {
|
|
|
|
/* Grab the rng_lock briefly to ensure that the hwrng interface
|
|
* gets priority over other user access
|
|
*/
|
|
result = mutex_lock_interruptible(&dev->rng_lock);
|
|
if (result)
|
|
goto bail;
|
|
mutex_unlock(&dev->rng_lock);
|
|
|
|
result = mutex_lock_interruptible(&dev->lock);
|
|
if (result)
|
|
goto bail;
|
|
if (dev->valid == dev->used) {
|
|
result = _chaoskey_fill(dev);
|
|
if (result < 0) {
|
|
mutex_unlock(&dev->lock);
|
|
goto bail;
|
|
}
|
|
}
|
|
|
|
this_time = dev->valid - dev->used;
|
|
if (this_time > count)
|
|
this_time = count;
|
|
|
|
remain = copy_to_user(buffer, dev->buf + dev->used, this_time);
|
|
if (remain) {
|
|
result = -EFAULT;
|
|
|
|
/* Consume the bytes that were copied so we don't leak
|
|
* data to user space
|
|
*/
|
|
dev->used += this_time - remain;
|
|
mutex_unlock(&dev->lock);
|
|
goto bail;
|
|
}
|
|
|
|
count -= this_time;
|
|
read_count += this_time;
|
|
buffer += this_time;
|
|
dev->used += this_time;
|
|
mutex_unlock(&dev->lock);
|
|
}
|
|
bail:
|
|
if (read_count) {
|
|
usb_dbg(dev->interface, "read %zu bytes", read_count);
|
|
return read_count;
|
|
}
|
|
usb_dbg(dev->interface, "empty read, result %d", result);
|
|
if (result == -ETIMEDOUT)
|
|
result = -EAGAIN;
|
|
return result;
|
|
}
|
|
|
|
static int chaoskey_rng_read(struct hwrng *rng, void *data,
|
|
size_t max, bool wait)
|
|
{
|
|
struct chaoskey *dev = container_of(rng, struct chaoskey, hwrng);
|
|
int this_time;
|
|
|
|
usb_dbg(dev->interface, "rng_read max %zu wait %d", max, wait);
|
|
|
|
if (!dev->present) {
|
|
usb_dbg(dev->interface, "device not present");
|
|
return 0;
|
|
}
|
|
|
|
/* Hold the rng_lock until we acquire the device lock so that
|
|
* this operation gets priority over other user access to the
|
|
* device
|
|
*/
|
|
mutex_lock(&dev->rng_lock);
|
|
|
|
mutex_lock(&dev->lock);
|
|
|
|
mutex_unlock(&dev->rng_lock);
|
|
|
|
/* Try to fill the buffer if empty. It doesn't actually matter
|
|
* if _chaoskey_fill works; we'll just return zero bytes as
|
|
* the buffer will still be empty
|
|
*/
|
|
if (dev->valid == dev->used)
|
|
(void) _chaoskey_fill(dev);
|
|
|
|
this_time = dev->valid - dev->used;
|
|
if (this_time > max)
|
|
this_time = max;
|
|
|
|
memcpy(data, dev->buf + dev->used, this_time);
|
|
|
|
dev->used += this_time;
|
|
|
|
mutex_unlock(&dev->lock);
|
|
|
|
usb_dbg(dev->interface, "rng_read this_time %d\n", this_time);
|
|
return this_time;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int chaoskey_suspend(struct usb_interface *interface,
|
|
pm_message_t message)
|
|
{
|
|
usb_dbg(interface, "suspend");
|
|
return 0;
|
|
}
|
|
|
|
static int chaoskey_resume(struct usb_interface *interface)
|
|
{
|
|
struct chaoskey *dev;
|
|
struct usb_device *udev = interface_to_usbdev(interface);
|
|
|
|
usb_dbg(interface, "resume");
|
|
dev = usb_get_intfdata(interface);
|
|
|
|
/*
|
|
* We may have lost power.
|
|
* In that case the device that needs a long time
|
|
* for the first requests needs an extended timeout
|
|
* again
|
|
*/
|
|
if (le16_to_cpu(udev->descriptor.idVendor) == ALEA_VENDOR_ID)
|
|
dev->reads_started = false;
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
#define chaoskey_suspend NULL
|
|
#define chaoskey_resume NULL
|
|
#endif
|
|
|
|
/* file operation pointers */
|
|
static const struct file_operations chaoskey_fops = {
|
|
.owner = THIS_MODULE,
|
|
.read = chaoskey_read,
|
|
.open = chaoskey_open,
|
|
.release = chaoskey_release,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
/* class driver information */
|
|
static struct usb_class_driver chaoskey_class = {
|
|
.name = "chaoskey%d",
|
|
.fops = &chaoskey_fops,
|
|
.minor_base = USB_CHAOSKEY_MINOR_BASE,
|
|
};
|
|
|
|
/* usb specific object needed to register this driver with the usb subsystem */
|
|
static struct usb_driver chaoskey_driver = {
|
|
.name = DRIVER_SHORT,
|
|
.probe = chaoskey_probe,
|
|
.disconnect = chaoskey_disconnect,
|
|
.suspend = chaoskey_suspend,
|
|
.resume = chaoskey_resume,
|
|
.reset_resume = chaoskey_resume,
|
|
.id_table = chaoskey_table,
|
|
.supports_autosuspend = 1,
|
|
};
|
|
|
|
module_usb_driver(chaoskey_driver);
|
|
|