diff options
author | Christian Mauderer <Christian.Mauderer@embedded-brains.de> | 2016-11-16 13:20:05 +0100 |
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committer | Christian Mauderer <Christian.Mauderer@embedded-brains.de> | 2017-01-17 12:50:57 +0100 |
commit | 2e8dd24b7ca59d2dcf96d4479acd3edd12f3b21d (patch) | |
tree | e159418ec207f01870d0229989614ec408c99dbb | |
parent | Port IEEE 802.11. (diff) | |
download | rtems-libbsd-2e8dd24b7ca59d2dcf96d4479acd3edd12f3b21d.tar.bz2 |
firmware: Import from FreeBSD.
-rw-r--r-- | freebsd/sys/kern/subr_firmware.c | 528 | ||||
-rw-r--r-- | freebsd/sys/sys/firmware.h | 64 |
2 files changed, 592 insertions, 0 deletions
diff --git a/freebsd/sys/kern/subr_firmware.c b/freebsd/sys/kern/subr_firmware.c new file mode 100644 index 00000000..9d3ec1ef --- /dev/null +++ b/freebsd/sys/kern/subr_firmware.c @@ -0,0 +1,528 @@ +#include <machine/rtems-bsd-kernel-space.h> + +/*- + * Copyright (c) 2005-2008, Sam Leffler <sam@errno.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice unmodified, this list of conditions, and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <rtems/bsd/sys/param.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/queue.h> +#include <sys/taskqueue.h> +#include <sys/systm.h> +#include <rtems/bsd/sys/lock.h> +#include <sys/mutex.h> +#include <rtems/bsd/sys/errno.h> +#include <sys/linker.h> +#include <sys/firmware.h> +#include <sys/priv.h> +#include <sys/proc.h> +#include <sys/module.h> +#include <sys/eventhandler.h> + +#include <sys/filedesc.h> +#include <sys/vnode.h> + +/* + * Loadable firmware support. See sys/sys/firmware.h and firmware(9) + * form more details on the subsystem. + * + * 'struct firmware' is the user-visible part of the firmware table. + * Additional internal information is stored in a 'struct priv_fw' + * (currently a static array). A slot is in use if FW_INUSE is true: + */ + +#define FW_INUSE(p) ((p)->file != NULL || (p)->fw.name != NULL) + +/* + * fw.name != NULL when an image is registered; file != NULL for + * autoloaded images whose handling has not been completed. + * + * The state of a slot evolves as follows: + * firmware_register --> fw.name = image_name + * (autoloaded image) --> file = module reference + * firmware_unregister --> fw.name = NULL + * (unloadentry complete) --> file = NULL + * + * In order for the above to work, the 'file' field must remain + * unchanged in firmware_unregister(). + * + * Images residing in the same module are linked to each other + * through the 'parent' argument of firmware_register(). + * One image (typically, one with the same name as the module to let + * the autoloading mechanism work) is considered the parent image for + * all other images in the same module. Children affect the refcount + * on the parent image preventing improper unloading of the image itself. + */ + +struct priv_fw { + int refcnt; /* reference count */ + + /* + * parent entry, see above. Set on firmware_register(), + * cleared on firmware_unregister(). + */ + struct priv_fw *parent; + + int flags; /* record FIRMWARE_UNLOAD requests */ +#define FW_UNLOAD 0x100 + + /* + * 'file' is private info managed by the autoload/unload code. + * Set at the end of firmware_get(), cleared only in the + * firmware_unload_task, so the latter can depend on its value even + * while the lock is not held. + */ + linker_file_t file; /* module file, if autoloaded */ + + /* + * 'fw' is the externally visible image information. + * We do not make it the first field in priv_fw, to avoid the + * temptation of casting pointers to each other. + * Use PRIV_FW(fw) to get a pointer to the cointainer of fw. + * Beware, PRIV_FW does not work for a NULL pointer. + */ + struct firmware fw; /* externally visible information */ +}; + +/* + * PRIV_FW returns the pointer to the container of struct firmware *x. + * Cast to intptr_t to override the 'const' attribute of x + */ +#define PRIV_FW(x) ((struct priv_fw *) \ + ((intptr_t)(x) - offsetof(struct priv_fw, fw)) ) + +/* + * At the moment we use a static array as backing store for the registry. + * Should we move to a dynamic structure, keep in mind that we cannot + * reallocate the array because pointers are held externally. + * A list may work, though. + */ +#define FIRMWARE_MAX 50 +static struct priv_fw firmware_table[FIRMWARE_MAX]; + +/* + * Firmware module operations are handled in a separate task as they + * might sleep and they require directory context to do i/o. + */ +static struct taskqueue *firmware_tq; +static struct task firmware_unload_task; + +/* + * This mutex protects accesses to the firmware table. + */ +static struct mtx firmware_mtx; +MTX_SYSINIT(firmware, &firmware_mtx, "firmware table", MTX_DEF); + +/* + * Helper function to lookup a name. + * As a side effect, it sets the pointer to a free slot, if any. + * This way we can concentrate most of the registry scanning in + * this function, which makes it easier to replace the registry + * with some other data structure. + */ +static struct priv_fw * +lookup(const char *name, struct priv_fw **empty_slot) +{ + struct priv_fw *fp = NULL; + struct priv_fw *dummy; + int i; + + if (empty_slot == NULL) + empty_slot = &dummy; + *empty_slot = NULL; + for (i = 0; i < FIRMWARE_MAX; i++) { + fp = &firmware_table[i]; + if (fp->fw.name != NULL && strcasecmp(name, fp->fw.name) == 0) + break; + else if (!FW_INUSE(fp)) + *empty_slot = fp; + } + return (i < FIRMWARE_MAX ) ? fp : NULL; +} + +/* + * Register a firmware image with the specified name. The + * image name must not already be registered. If this is a + * subimage then parent refers to a previously registered + * image that this should be associated with. + */ +const struct firmware * +firmware_register(const char *imagename, const void *data, size_t datasize, + unsigned int version, const struct firmware *parent) +{ + struct priv_fw *match, *frp; + char *str; + + str = strdup(imagename, M_TEMP); + + mtx_lock(&firmware_mtx); + /* + * Do a lookup to make sure the name is unique or find a free slot. + */ + match = lookup(imagename, &frp); + if (match != NULL) { + mtx_unlock(&firmware_mtx); + printf("%s: image %s already registered!\n", + __func__, imagename); + free(str, M_TEMP); + return NULL; + } + if (frp == NULL) { + mtx_unlock(&firmware_mtx); + printf("%s: cannot register image %s, firmware table full!\n", + __func__, imagename); + free(str, M_TEMP); + return NULL; + } + bzero(frp, sizeof(*frp)); /* start from a clean record */ + frp->fw.name = str; + frp->fw.data = data; + frp->fw.datasize = datasize; + frp->fw.version = version; + if (parent != NULL) + frp->parent = PRIV_FW(parent); + mtx_unlock(&firmware_mtx); + if (bootverbose) + printf("firmware: '%s' version %u: %zu bytes loaded at %p\n", + imagename, version, datasize, data); + return &frp->fw; +} + +/* + * Unregister/remove a firmware image. If there are outstanding + * references an error is returned and the image is not removed + * from the registry. + */ +int +firmware_unregister(const char *imagename) +{ + struct priv_fw *fp; + int err; + + mtx_lock(&firmware_mtx); + fp = lookup(imagename, NULL); + if (fp == NULL) { + /* + * It is ok for the lookup to fail; this can happen + * when a module is unloaded on last reference and the + * module unload handler unregister's each of its + * firmware images. + */ + err = 0; + } else if (fp->refcnt != 0) { /* cannot unregister */ + err = EBUSY; + } else { + linker_file_t x = fp->file; /* save value */ + + /* + * Clear the whole entry with bzero to make sure we + * do not forget anything. Then restore 'file' which is + * non-null for autoloaded images. + */ + free((void *) (uintptr_t) fp->fw.name, M_TEMP); + bzero(fp, sizeof(struct priv_fw)); + fp->file = x; + err = 0; + } + mtx_unlock(&firmware_mtx); + return err; +} + +static void +loadimage(void *arg, int npending) +{ + struct thread *td = curthread; + char *imagename = arg; + struct priv_fw *fp; + linker_file_t result; + int error; + + /* synchronize with the thread that dispatched us */ + mtx_lock(&firmware_mtx); + mtx_unlock(&firmware_mtx); + + if (td->td_proc->p_fd->fd_rdir == NULL) { + printf("%s: root not mounted yet, no way to load image\n", + imagename); + goto done; + } + error = linker_reference_module(imagename, NULL, &result); + if (error != 0) { + printf("%s: could not load firmware image, error %d\n", + imagename, error); + goto done; + } + + mtx_lock(&firmware_mtx); + fp = lookup(imagename, NULL); + if (fp == NULL || fp->file != NULL) { + mtx_unlock(&firmware_mtx); + if (fp == NULL) + printf("%s: firmware image loaded, " + "but did not register\n", imagename); + (void) linker_release_module(imagename, NULL, NULL); + goto done; + } + fp->file = result; /* record the module identity */ + mtx_unlock(&firmware_mtx); +done: + wakeup_one(imagename); /* we're done */ +} + +/* + * Lookup and potentially load the specified firmware image. + * If the firmware is not found in the registry, try to load a kernel + * module named as the image name. + * If the firmware is located, a reference is returned. The caller must + * release this reference for the image to be eligible for removal/unload. + */ +const struct firmware * +firmware_get(const char *imagename) +{ + struct task fwload_task; + struct thread *td; + struct priv_fw *fp; + + mtx_lock(&firmware_mtx); + fp = lookup(imagename, NULL); + if (fp != NULL) + goto found; + /* + * Image not present, try to load the module holding it. + */ + td = curthread; + if (priv_check(td, PRIV_FIRMWARE_LOAD) != 0 || + securelevel_gt(td->td_ucred, 0) != 0) { + mtx_unlock(&firmware_mtx); + printf("%s: insufficient privileges to " + "load firmware image %s\n", __func__, imagename); + return NULL; + } + /* + * Defer load to a thread with known context. linker_reference_module + * may do filesystem i/o which requires root & current dirs, etc. + * Also we must not hold any mtx's over this call which is problematic. + */ + if (!cold) { + TASK_INIT(&fwload_task, 0, loadimage, __DECONST(void *, + imagename)); + taskqueue_enqueue(firmware_tq, &fwload_task); + msleep(__DECONST(void *, imagename), &firmware_mtx, 0, + "fwload", 0); + } + /* + * After attempting to load the module, see if the image is registered. + */ + fp = lookup(imagename, NULL); + if (fp == NULL) { + mtx_unlock(&firmware_mtx); + return NULL; + } +found: /* common exit point on success */ + if (fp->refcnt == 0 && fp->parent != NULL) + fp->parent->refcnt++; + fp->refcnt++; + mtx_unlock(&firmware_mtx); + return &fp->fw; +} + +/* + * Release a reference to a firmware image returned by firmware_get. + * The caller may specify, with the FIRMWARE_UNLOAD flag, its desire + * to release the resource, but the flag is only advisory. + * + * If this is the last reference to the firmware image, and this is an + * autoloaded module, wake up the firmware_unload_task to figure out + * what to do with the associated module. + */ +void +firmware_put(const struct firmware *p, int flags) +{ + struct priv_fw *fp = PRIV_FW(p); + + mtx_lock(&firmware_mtx); + fp->refcnt--; + if (fp->refcnt == 0) { + if (fp->parent != NULL) + fp->parent->refcnt--; + if (flags & FIRMWARE_UNLOAD) + fp->flags |= FW_UNLOAD; + if (fp->file) + taskqueue_enqueue(firmware_tq, &firmware_unload_task); + } + mtx_unlock(&firmware_mtx); +} + +/* + * Setup directory state for the firmware_tq thread so we can do i/o. + */ +static void +set_rootvnode(void *arg, int npending) +{ + + pwd_ensure_dirs(); + + free(arg, M_TEMP); +} + +/* + * Event handler called on mounting of /; bounce a task + * into the task queue thread to setup it's directories. + */ +static void +firmware_mountroot(void *arg) +{ + struct task *setroot_task; + + setroot_task = malloc(sizeof(struct task), M_TEMP, M_NOWAIT); + if (setroot_task != NULL) { + TASK_INIT(setroot_task, 0, set_rootvnode, setroot_task); + taskqueue_enqueue(firmware_tq, setroot_task); + } else + printf("%s: no memory for task!\n", __func__); +} +EVENTHANDLER_DEFINE(mountroot, firmware_mountroot, NULL, 0); + +/* + * The body of the task in charge of unloading autoloaded modules + * that are not needed anymore. + * Images can be cross-linked so we may need to make multiple passes, + * but the time we spend in the loop is bounded because we clear entries + * as we touch them. + */ +static void +unloadentry(void *unused1, int unused2) +{ + int limit = FIRMWARE_MAX; + int i; /* current cycle */ + + mtx_lock(&firmware_mtx); + /* + * Scan the table. limit is set to make sure we make another + * full sweep after matching an entry that requires unloading. + */ + for (i = 0; i < limit; i++) { + struct priv_fw *fp; + int err; + + fp = &firmware_table[i % FIRMWARE_MAX]; + if (fp->fw.name == NULL || fp->file == NULL || + fp->refcnt != 0 || (fp->flags & FW_UNLOAD) == 0) + continue; + + /* + * Found an entry. Now: + * 1. bump up limit to make sure we make another full round; + * 2. clear FW_UNLOAD so we don't try this entry again. + * 3. release the lock while trying to unload the module. + * 'file' remains set so that the entry cannot be reused + * in the meantime (it also means that fp->file will + * not change while we release the lock). + */ + limit = i + FIRMWARE_MAX; /* make another full round */ + fp->flags &= ~FW_UNLOAD; /* do not try again */ + + mtx_unlock(&firmware_mtx); + err = linker_release_module(NULL, NULL, fp->file); + mtx_lock(&firmware_mtx); + + /* + * We rely on the module to call firmware_unregister() + * on unload to actually release the entry. + * If err = 0 we can drop our reference as the system + * accepted it. Otherwise unloading failed (e.g. the + * module itself gave an error) so our reference is + * still valid. + */ + if (err == 0) + fp->file = NULL; + } + mtx_unlock(&firmware_mtx); +} + +/* + * Module glue. + */ +static int +firmware_modevent(module_t mod, int type, void *unused) +{ + struct priv_fw *fp; + int i, err; + + switch (type) { + case MOD_LOAD: + TASK_INIT(&firmware_unload_task, 0, unloadentry, NULL); + firmware_tq = taskqueue_create("taskqueue_firmware", M_WAITOK, + taskqueue_thread_enqueue, &firmware_tq); + /* NB: use our own loop routine that sets up context */ + (void) taskqueue_start_threads(&firmware_tq, 1, PWAIT, + "firmware taskq"); + if (rootvnode != NULL) { + /* + * Root is already mounted so we won't get an event; + * simulate one here. + */ + firmware_mountroot(NULL); + } + return 0; + + case MOD_UNLOAD: + /* request all autoloaded modules to be released */ + mtx_lock(&firmware_mtx); + for (i = 0; i < FIRMWARE_MAX; i++) { + fp = &firmware_table[i]; + fp->flags |= FW_UNLOAD; + } + mtx_unlock(&firmware_mtx); + taskqueue_enqueue(firmware_tq, &firmware_unload_task); + taskqueue_drain(firmware_tq, &firmware_unload_task); + err = 0; + for (i = 0; i < FIRMWARE_MAX; i++) { + fp = &firmware_table[i]; + if (fp->fw.name != NULL) { + printf("%s: image %p ref %d still active slot %d\n", + __func__, fp->fw.name, + fp->refcnt, i); + err = EINVAL; + } + } + if (err == 0) + taskqueue_free(firmware_tq); + return err; + } + return EINVAL; +} + +static moduledata_t firmware_mod = { + "firmware", + firmware_modevent, + NULL +}; +DECLARE_MODULE(firmware, firmware_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); +MODULE_VERSION(firmware, 1); diff --git a/freebsd/sys/sys/firmware.h b/freebsd/sys/sys/firmware.h new file mode 100644 index 00000000..ce02831a --- /dev/null +++ b/freebsd/sys/sys/firmware.h @@ -0,0 +1,64 @@ +/*- + * Copyright (c) 2005, Sam Leffler <sam@errno.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice unmodified, this list of conditions, and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $FreeBSD$ + */ +#ifndef _SYS_FIRMWARE_H_ +#define _SYS_FIRMWARE_H_ +/* + * Loadable firmware support. + * + * The firmware abstraction provides an interface for loading firmware + * images into the kernel and making them available to clients. + * + * Firmware images are usually embedded in kernel loadable modules that can + * be loaded on-demand or pre-loaded as desired. Modules may contain + * one or more firmware images that are stored as opaque data arrays + * and registered with a unique string name. Clients request + * firmware by name, and are returned a struct firmware * below on success. + * The kernel keeps track of references to firmware images to allow/prevent + * module/data unload. + * + * When multiple images are stored in one module, the first image is + * treated as the master with the other images holding references + * to it. This means that to unload the module each dependent/subimage + * must first have its references removed. + * In order for automatic loading to work, the master image must have + * the same name as the module it is embedded into. + */ +struct firmware { + const char *name; /* system-wide name */ + const void *data; /* location of image */ + size_t datasize; /* size of image in bytes */ + unsigned int version; /* version of the image */ +}; + +const struct firmware *firmware_register(const char *, + const void *, size_t, unsigned int, const struct firmware *); +int firmware_unregister(const char *); +const struct firmware *firmware_get(const char *); +#define FIRMWARE_UNLOAD 0x0001 /* unload if unreferenced */ +void firmware_put(const struct firmware *, int); +#endif /* _SYS_FIRMWARE_H_ */ |