17bd1d409SAlexander Shishkin /* 27bd1d409SAlexander Shishkin * System Trace Module (STM) infrastructure 37bd1d409SAlexander Shishkin * Copyright (c) 2014, Intel Corporation. 47bd1d409SAlexander Shishkin * 57bd1d409SAlexander Shishkin * This program is free software; you can redistribute it and/or modify it 67bd1d409SAlexander Shishkin * under the terms and conditions of the GNU General Public License, 77bd1d409SAlexander Shishkin * version 2, as published by the Free Software Foundation. 87bd1d409SAlexander Shishkin * 97bd1d409SAlexander Shishkin * This program is distributed in the hope it will be useful, but WITHOUT 107bd1d409SAlexander Shishkin * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 117bd1d409SAlexander Shishkin * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 127bd1d409SAlexander Shishkin * more details. 137bd1d409SAlexander Shishkin * 147bd1d409SAlexander Shishkin * STM class implements generic infrastructure for System Trace Module devices 157bd1d409SAlexander Shishkin * as defined in MIPI STPv2 specification. 167bd1d409SAlexander Shishkin */ 177bd1d409SAlexander Shishkin 187bd1d409SAlexander Shishkin #include <linux/uaccess.h> 197bd1d409SAlexander Shishkin #include <linux/kernel.h> 207bd1d409SAlexander Shishkin #include <linux/module.h> 217bd1d409SAlexander Shishkin #include <linux/device.h> 227bd1d409SAlexander Shishkin #include <linux/compat.h> 237bd1d409SAlexander Shishkin #include <linux/kdev_t.h> 247bd1d409SAlexander Shishkin #include <linux/srcu.h> 257bd1d409SAlexander Shishkin #include <linux/slab.h> 267bd1d409SAlexander Shishkin #include <linux/stm.h> 277bd1d409SAlexander Shishkin #include <linux/fs.h> 287bd1d409SAlexander Shishkin #include <linux/mm.h> 297bd1d409SAlexander Shishkin #include "stm.h" 307bd1d409SAlexander Shishkin 317bd1d409SAlexander Shishkin #include <uapi/linux/stm.h> 327bd1d409SAlexander Shishkin 337bd1d409SAlexander Shishkin static unsigned int stm_core_up; 347bd1d409SAlexander Shishkin 357bd1d409SAlexander Shishkin /* 367bd1d409SAlexander Shishkin * The SRCU here makes sure that STM device doesn't disappear from under a 377bd1d409SAlexander Shishkin * stm_source_write() caller, which may want to have as little overhead as 387bd1d409SAlexander Shishkin * possible. 397bd1d409SAlexander Shishkin */ 407bd1d409SAlexander Shishkin static struct srcu_struct stm_source_srcu; 417bd1d409SAlexander Shishkin 427bd1d409SAlexander Shishkin static ssize_t masters_show(struct device *dev, 437bd1d409SAlexander Shishkin struct device_attribute *attr, 447bd1d409SAlexander Shishkin char *buf) 457bd1d409SAlexander Shishkin { 467bd1d409SAlexander Shishkin struct stm_device *stm = to_stm_device(dev); 477bd1d409SAlexander Shishkin int ret; 487bd1d409SAlexander Shishkin 497bd1d409SAlexander Shishkin ret = sprintf(buf, "%u %u\n", stm->data->sw_start, stm->data->sw_end); 507bd1d409SAlexander Shishkin 517bd1d409SAlexander Shishkin return ret; 527bd1d409SAlexander Shishkin } 537bd1d409SAlexander Shishkin 547bd1d409SAlexander Shishkin static DEVICE_ATTR_RO(masters); 557bd1d409SAlexander Shishkin 567bd1d409SAlexander Shishkin static ssize_t channels_show(struct device *dev, 577bd1d409SAlexander Shishkin struct device_attribute *attr, 587bd1d409SAlexander Shishkin char *buf) 597bd1d409SAlexander Shishkin { 607bd1d409SAlexander Shishkin struct stm_device *stm = to_stm_device(dev); 617bd1d409SAlexander Shishkin int ret; 627bd1d409SAlexander Shishkin 637bd1d409SAlexander Shishkin ret = sprintf(buf, "%u\n", stm->data->sw_nchannels); 647bd1d409SAlexander Shishkin 657bd1d409SAlexander Shishkin return ret; 667bd1d409SAlexander Shishkin } 677bd1d409SAlexander Shishkin 687bd1d409SAlexander Shishkin static DEVICE_ATTR_RO(channels); 697bd1d409SAlexander Shishkin 708e996a28SAlexander Shishkin static ssize_t hw_override_show(struct device *dev, 718e996a28SAlexander Shishkin struct device_attribute *attr, 728e996a28SAlexander Shishkin char *buf) 738e996a28SAlexander Shishkin { 748e996a28SAlexander Shishkin struct stm_device *stm = to_stm_device(dev); 758e996a28SAlexander Shishkin int ret; 768e996a28SAlexander Shishkin 778e996a28SAlexander Shishkin ret = sprintf(buf, "%u\n", stm->data->hw_override); 788e996a28SAlexander Shishkin 798e996a28SAlexander Shishkin return ret; 808e996a28SAlexander Shishkin } 818e996a28SAlexander Shishkin 828e996a28SAlexander Shishkin static DEVICE_ATTR_RO(hw_override); 838e996a28SAlexander Shishkin 847bd1d409SAlexander Shishkin static struct attribute *stm_attrs[] = { 857bd1d409SAlexander Shishkin &dev_attr_masters.attr, 867bd1d409SAlexander Shishkin &dev_attr_channels.attr, 878e996a28SAlexander Shishkin &dev_attr_hw_override.attr, 887bd1d409SAlexander Shishkin NULL, 897bd1d409SAlexander Shishkin }; 907bd1d409SAlexander Shishkin 917bd1d409SAlexander Shishkin ATTRIBUTE_GROUPS(stm); 927bd1d409SAlexander Shishkin 937bd1d409SAlexander Shishkin static struct class stm_class = { 947bd1d409SAlexander Shishkin .name = "stm", 957bd1d409SAlexander Shishkin .dev_groups = stm_groups, 967bd1d409SAlexander Shishkin }; 977bd1d409SAlexander Shishkin 987bd1d409SAlexander Shishkin static int stm_dev_match(struct device *dev, const void *data) 997bd1d409SAlexander Shishkin { 1007bd1d409SAlexander Shishkin const char *name = data; 1017bd1d409SAlexander Shishkin 1027bd1d409SAlexander Shishkin return sysfs_streq(name, dev_name(dev)); 1037bd1d409SAlexander Shishkin } 1047bd1d409SAlexander Shishkin 1057bd1d409SAlexander Shishkin /** 1067bd1d409SAlexander Shishkin * stm_find_device() - find stm device by name 1077bd1d409SAlexander Shishkin * @buf: character buffer containing the name 1087bd1d409SAlexander Shishkin * 1097bd1d409SAlexander Shishkin * This is called when either policy gets assigned to an stm device or an 1107bd1d409SAlexander Shishkin * stm_source device gets linked to an stm device. 1117bd1d409SAlexander Shishkin * 1127bd1d409SAlexander Shishkin * This grabs device's reference (get_device()) and module reference, both 1137bd1d409SAlexander Shishkin * of which the calling path needs to make sure to drop with stm_put_device(). 1147bd1d409SAlexander Shishkin * 1157bd1d409SAlexander Shishkin * Return: stm device pointer or null if lookup failed. 1167bd1d409SAlexander Shishkin */ 1177bd1d409SAlexander Shishkin struct stm_device *stm_find_device(const char *buf) 1187bd1d409SAlexander Shishkin { 1197bd1d409SAlexander Shishkin struct stm_device *stm; 1207bd1d409SAlexander Shishkin struct device *dev; 1217bd1d409SAlexander Shishkin 1227bd1d409SAlexander Shishkin if (!stm_core_up) 1237bd1d409SAlexander Shishkin return NULL; 1247bd1d409SAlexander Shishkin 1257bd1d409SAlexander Shishkin dev = class_find_device(&stm_class, NULL, buf, stm_dev_match); 1267bd1d409SAlexander Shishkin if (!dev) 1277bd1d409SAlexander Shishkin return NULL; 1287bd1d409SAlexander Shishkin 1297bd1d409SAlexander Shishkin stm = to_stm_device(dev); 1307bd1d409SAlexander Shishkin if (!try_module_get(stm->owner)) { 131f7c81c71SAlexander Shishkin /* matches class_find_device() above */ 1327bd1d409SAlexander Shishkin put_device(dev); 1337bd1d409SAlexander Shishkin return NULL; 1347bd1d409SAlexander Shishkin } 1357bd1d409SAlexander Shishkin 1367bd1d409SAlexander Shishkin return stm; 1377bd1d409SAlexander Shishkin } 1387bd1d409SAlexander Shishkin 1397bd1d409SAlexander Shishkin /** 1407bd1d409SAlexander Shishkin * stm_put_device() - drop references on the stm device 1417bd1d409SAlexander Shishkin * @stm: stm device, previously acquired by stm_find_device() 1427bd1d409SAlexander Shishkin * 1437bd1d409SAlexander Shishkin * This drops the module reference and device reference taken by 144f7c81c71SAlexander Shishkin * stm_find_device() or stm_char_open(). 1457bd1d409SAlexander Shishkin */ 1467bd1d409SAlexander Shishkin void stm_put_device(struct stm_device *stm) 1477bd1d409SAlexander Shishkin { 1487bd1d409SAlexander Shishkin module_put(stm->owner); 1497bd1d409SAlexander Shishkin put_device(&stm->dev); 1507bd1d409SAlexander Shishkin } 1517bd1d409SAlexander Shishkin 1527bd1d409SAlexander Shishkin /* 1537bd1d409SAlexander Shishkin * Internally we only care about software-writable masters here, that is the 1547bd1d409SAlexander Shishkin * ones in the range [stm_data->sw_start..stm_data..sw_end], however we need 1557bd1d409SAlexander Shishkin * original master numbers to be visible externally, since they are the ones 1567bd1d409SAlexander Shishkin * that will appear in the STP stream. Thus, the internal bookkeeping uses 1577bd1d409SAlexander Shishkin * $master - stm_data->sw_start to reference master descriptors and such. 1587bd1d409SAlexander Shishkin */ 1597bd1d409SAlexander Shishkin 1607bd1d409SAlexander Shishkin #define __stm_master(_s, _m) \ 1617bd1d409SAlexander Shishkin ((_s)->masters[(_m) - (_s)->data->sw_start]) 1627bd1d409SAlexander Shishkin 1637bd1d409SAlexander Shishkin static inline struct stp_master * 1647bd1d409SAlexander Shishkin stm_master(struct stm_device *stm, unsigned int idx) 1657bd1d409SAlexander Shishkin { 1667bd1d409SAlexander Shishkin if (idx < stm->data->sw_start || idx > stm->data->sw_end) 1677bd1d409SAlexander Shishkin return NULL; 1687bd1d409SAlexander Shishkin 1697bd1d409SAlexander Shishkin return __stm_master(stm, idx); 1707bd1d409SAlexander Shishkin } 1717bd1d409SAlexander Shishkin 1727bd1d409SAlexander Shishkin static int stp_master_alloc(struct stm_device *stm, unsigned int idx) 1737bd1d409SAlexander Shishkin { 1747bd1d409SAlexander Shishkin struct stp_master *master; 1757bd1d409SAlexander Shishkin size_t size; 1767bd1d409SAlexander Shishkin 1777bd1d409SAlexander Shishkin size = ALIGN(stm->data->sw_nchannels, 8) / 8; 1787bd1d409SAlexander Shishkin size += sizeof(struct stp_master); 1797bd1d409SAlexander Shishkin master = kzalloc(size, GFP_ATOMIC); 1807bd1d409SAlexander Shishkin if (!master) 1817bd1d409SAlexander Shishkin return -ENOMEM; 1827bd1d409SAlexander Shishkin 1837bd1d409SAlexander Shishkin master->nr_free = stm->data->sw_nchannels; 1847bd1d409SAlexander Shishkin __stm_master(stm, idx) = master; 1857bd1d409SAlexander Shishkin 1867bd1d409SAlexander Shishkin return 0; 1877bd1d409SAlexander Shishkin } 1887bd1d409SAlexander Shishkin 1897bd1d409SAlexander Shishkin static void stp_master_free(struct stm_device *stm, unsigned int idx) 1907bd1d409SAlexander Shishkin { 1917bd1d409SAlexander Shishkin struct stp_master *master = stm_master(stm, idx); 1927bd1d409SAlexander Shishkin 1937bd1d409SAlexander Shishkin if (!master) 1947bd1d409SAlexander Shishkin return; 1957bd1d409SAlexander Shishkin 1967bd1d409SAlexander Shishkin __stm_master(stm, idx) = NULL; 1977bd1d409SAlexander Shishkin kfree(master); 1987bd1d409SAlexander Shishkin } 1997bd1d409SAlexander Shishkin 2007bd1d409SAlexander Shishkin static void stm_output_claim(struct stm_device *stm, struct stm_output *output) 2017bd1d409SAlexander Shishkin { 2027bd1d409SAlexander Shishkin struct stp_master *master = stm_master(stm, output->master); 2037bd1d409SAlexander Shishkin 204cde4ad83SAlexander Shishkin lockdep_assert_held(&stm->mc_lock); 205cde4ad83SAlexander Shishkin lockdep_assert_held(&output->lock); 206cde4ad83SAlexander Shishkin 2077bd1d409SAlexander Shishkin if (WARN_ON_ONCE(master->nr_free < output->nr_chans)) 2087bd1d409SAlexander Shishkin return; 2097bd1d409SAlexander Shishkin 2107bd1d409SAlexander Shishkin bitmap_allocate_region(&master->chan_map[0], output->channel, 2117bd1d409SAlexander Shishkin ilog2(output->nr_chans)); 2127bd1d409SAlexander Shishkin 2137bd1d409SAlexander Shishkin master->nr_free -= output->nr_chans; 2147bd1d409SAlexander Shishkin } 2157bd1d409SAlexander Shishkin 2167bd1d409SAlexander Shishkin static void 2177bd1d409SAlexander Shishkin stm_output_disclaim(struct stm_device *stm, struct stm_output *output) 2187bd1d409SAlexander Shishkin { 2197bd1d409SAlexander Shishkin struct stp_master *master = stm_master(stm, output->master); 2207bd1d409SAlexander Shishkin 221cde4ad83SAlexander Shishkin lockdep_assert_held(&stm->mc_lock); 222cde4ad83SAlexander Shishkin lockdep_assert_held(&output->lock); 223cde4ad83SAlexander Shishkin 2247bd1d409SAlexander Shishkin bitmap_release_region(&master->chan_map[0], output->channel, 2257bd1d409SAlexander Shishkin ilog2(output->nr_chans)); 2267bd1d409SAlexander Shishkin 2277bd1d409SAlexander Shishkin output->nr_chans = 0; 2287bd1d409SAlexander Shishkin master->nr_free += output->nr_chans; 2297bd1d409SAlexander Shishkin } 2307bd1d409SAlexander Shishkin 2317bd1d409SAlexander Shishkin /* 2327bd1d409SAlexander Shishkin * This is like bitmap_find_free_region(), except it can ignore @start bits 2337bd1d409SAlexander Shishkin * at the beginning. 2347bd1d409SAlexander Shishkin */ 2357bd1d409SAlexander Shishkin static int find_free_channels(unsigned long *bitmap, unsigned int start, 2367bd1d409SAlexander Shishkin unsigned int end, unsigned int width) 2377bd1d409SAlexander Shishkin { 2387bd1d409SAlexander Shishkin unsigned int pos; 2397bd1d409SAlexander Shishkin int i; 2407bd1d409SAlexander Shishkin 2417bd1d409SAlexander Shishkin for (pos = start; pos < end + 1; pos = ALIGN(pos, width)) { 2427bd1d409SAlexander Shishkin pos = find_next_zero_bit(bitmap, end + 1, pos); 2437bd1d409SAlexander Shishkin if (pos + width > end + 1) 2447bd1d409SAlexander Shishkin break; 2457bd1d409SAlexander Shishkin 2467bd1d409SAlexander Shishkin if (pos & (width - 1)) 2477bd1d409SAlexander Shishkin continue; 2487bd1d409SAlexander Shishkin 2497bd1d409SAlexander Shishkin for (i = 1; i < width && !test_bit(pos + i, bitmap); i++) 2507bd1d409SAlexander Shishkin ; 2517bd1d409SAlexander Shishkin if (i == width) 2527bd1d409SAlexander Shishkin return pos; 2537bd1d409SAlexander Shishkin } 2547bd1d409SAlexander Shishkin 2557bd1d409SAlexander Shishkin return -1; 2567bd1d409SAlexander Shishkin } 2577bd1d409SAlexander Shishkin 258f45f40adSLucas Tanure static int 2597bd1d409SAlexander Shishkin stm_find_master_chan(struct stm_device *stm, unsigned int width, 2607bd1d409SAlexander Shishkin unsigned int *mstart, unsigned int mend, 2617bd1d409SAlexander Shishkin unsigned int *cstart, unsigned int cend) 2627bd1d409SAlexander Shishkin { 2637bd1d409SAlexander Shishkin struct stp_master *master; 2647bd1d409SAlexander Shishkin unsigned int midx; 2657bd1d409SAlexander Shishkin int pos, err; 2667bd1d409SAlexander Shishkin 2677bd1d409SAlexander Shishkin for (midx = *mstart; midx <= mend; midx++) { 2687bd1d409SAlexander Shishkin if (!stm_master(stm, midx)) { 2697bd1d409SAlexander Shishkin err = stp_master_alloc(stm, midx); 2707bd1d409SAlexander Shishkin if (err) 2717bd1d409SAlexander Shishkin return err; 2727bd1d409SAlexander Shishkin } 2737bd1d409SAlexander Shishkin 2747bd1d409SAlexander Shishkin master = stm_master(stm, midx); 2757bd1d409SAlexander Shishkin 2767bd1d409SAlexander Shishkin if (!master->nr_free) 2777bd1d409SAlexander Shishkin continue; 2787bd1d409SAlexander Shishkin 2797bd1d409SAlexander Shishkin pos = find_free_channels(master->chan_map, *cstart, cend, 2807bd1d409SAlexander Shishkin width); 2817bd1d409SAlexander Shishkin if (pos < 0) 2827bd1d409SAlexander Shishkin continue; 2837bd1d409SAlexander Shishkin 2847bd1d409SAlexander Shishkin *mstart = midx; 2857bd1d409SAlexander Shishkin *cstart = pos; 2867bd1d409SAlexander Shishkin return 0; 2877bd1d409SAlexander Shishkin } 2887bd1d409SAlexander Shishkin 2897bd1d409SAlexander Shishkin return -ENOSPC; 2907bd1d409SAlexander Shishkin } 2917bd1d409SAlexander Shishkin 2927bd1d409SAlexander Shishkin static int stm_output_assign(struct stm_device *stm, unsigned int width, 2937bd1d409SAlexander Shishkin struct stp_policy_node *policy_node, 2947bd1d409SAlexander Shishkin struct stm_output *output) 2957bd1d409SAlexander Shishkin { 2967bd1d409SAlexander Shishkin unsigned int midx, cidx, mend, cend; 2977bd1d409SAlexander Shishkin int ret = -EINVAL; 2987bd1d409SAlexander Shishkin 2997bd1d409SAlexander Shishkin if (width > stm->data->sw_nchannels) 3007bd1d409SAlexander Shishkin return -EINVAL; 3017bd1d409SAlexander Shishkin 3027bd1d409SAlexander Shishkin if (policy_node) { 3037bd1d409SAlexander Shishkin stp_policy_node_get_ranges(policy_node, 3047bd1d409SAlexander Shishkin &midx, &mend, &cidx, &cend); 3057bd1d409SAlexander Shishkin } else { 3067bd1d409SAlexander Shishkin midx = stm->data->sw_start; 3077bd1d409SAlexander Shishkin cidx = 0; 3087bd1d409SAlexander Shishkin mend = stm->data->sw_end; 3097bd1d409SAlexander Shishkin cend = stm->data->sw_nchannels - 1; 3107bd1d409SAlexander Shishkin } 3117bd1d409SAlexander Shishkin 3127bd1d409SAlexander Shishkin spin_lock(&stm->mc_lock); 313cde4ad83SAlexander Shishkin spin_lock(&output->lock); 3147bd1d409SAlexander Shishkin /* output is already assigned -- shouldn't happen */ 3157bd1d409SAlexander Shishkin if (WARN_ON_ONCE(output->nr_chans)) 3167bd1d409SAlexander Shishkin goto unlock; 3177bd1d409SAlexander Shishkin 3187bd1d409SAlexander Shishkin ret = stm_find_master_chan(stm, width, &midx, mend, &cidx, cend); 319f45f40adSLucas Tanure if (ret < 0) 3207bd1d409SAlexander Shishkin goto unlock; 3217bd1d409SAlexander Shishkin 3227bd1d409SAlexander Shishkin output->master = midx; 3237bd1d409SAlexander Shishkin output->channel = cidx; 3247bd1d409SAlexander Shishkin output->nr_chans = width; 3257bd1d409SAlexander Shishkin stm_output_claim(stm, output); 3267bd1d409SAlexander Shishkin dev_dbg(&stm->dev, "assigned %u:%u (+%u)\n", midx, cidx, width); 3277bd1d409SAlexander Shishkin 3287bd1d409SAlexander Shishkin ret = 0; 3297bd1d409SAlexander Shishkin unlock: 330cde4ad83SAlexander Shishkin spin_unlock(&output->lock); 3317bd1d409SAlexander Shishkin spin_unlock(&stm->mc_lock); 3327bd1d409SAlexander Shishkin 3337bd1d409SAlexander Shishkin return ret; 3347bd1d409SAlexander Shishkin } 3357bd1d409SAlexander Shishkin 3367bd1d409SAlexander Shishkin static void stm_output_free(struct stm_device *stm, struct stm_output *output) 3377bd1d409SAlexander Shishkin { 3387bd1d409SAlexander Shishkin spin_lock(&stm->mc_lock); 339cde4ad83SAlexander Shishkin spin_lock(&output->lock); 3407bd1d409SAlexander Shishkin if (output->nr_chans) 3417bd1d409SAlexander Shishkin stm_output_disclaim(stm, output); 342cde4ad83SAlexander Shishkin spin_unlock(&output->lock); 3437bd1d409SAlexander Shishkin spin_unlock(&stm->mc_lock); 3447bd1d409SAlexander Shishkin } 3457bd1d409SAlexander Shishkin 346cde4ad83SAlexander Shishkin static void stm_output_init(struct stm_output *output) 347cde4ad83SAlexander Shishkin { 348cde4ad83SAlexander Shishkin spin_lock_init(&output->lock); 349cde4ad83SAlexander Shishkin } 350cde4ad83SAlexander Shishkin 3517bd1d409SAlexander Shishkin static int major_match(struct device *dev, const void *data) 3527bd1d409SAlexander Shishkin { 3537bd1d409SAlexander Shishkin unsigned int major = *(unsigned int *)data; 3547bd1d409SAlexander Shishkin 3557bd1d409SAlexander Shishkin return MAJOR(dev->devt) == major; 3567bd1d409SAlexander Shishkin } 3577bd1d409SAlexander Shishkin 3587bd1d409SAlexander Shishkin static int stm_char_open(struct inode *inode, struct file *file) 3597bd1d409SAlexander Shishkin { 3607bd1d409SAlexander Shishkin struct stm_file *stmf; 3617bd1d409SAlexander Shishkin struct device *dev; 3627bd1d409SAlexander Shishkin unsigned int major = imajor(inode); 3637bd1d409SAlexander Shishkin int err = -ENODEV; 3647bd1d409SAlexander Shishkin 3657bd1d409SAlexander Shishkin dev = class_find_device(&stm_class, NULL, &major, major_match); 3667bd1d409SAlexander Shishkin if (!dev) 3677bd1d409SAlexander Shishkin return -ENODEV; 3687bd1d409SAlexander Shishkin 3697bd1d409SAlexander Shishkin stmf = kzalloc(sizeof(*stmf), GFP_KERNEL); 3707bd1d409SAlexander Shishkin if (!stmf) 3717bd1d409SAlexander Shishkin return -ENOMEM; 3727bd1d409SAlexander Shishkin 373cde4ad83SAlexander Shishkin stm_output_init(&stmf->output); 3747bd1d409SAlexander Shishkin stmf->stm = to_stm_device(dev); 3757bd1d409SAlexander Shishkin 3767bd1d409SAlexander Shishkin if (!try_module_get(stmf->stm->owner)) 3777bd1d409SAlexander Shishkin goto err_free; 3787bd1d409SAlexander Shishkin 3797bd1d409SAlexander Shishkin file->private_data = stmf; 3807bd1d409SAlexander Shishkin 3817bd1d409SAlexander Shishkin return nonseekable_open(inode, file); 3827bd1d409SAlexander Shishkin 3837bd1d409SAlexander Shishkin err_free: 384f7c81c71SAlexander Shishkin /* matches class_find_device() above */ 385f7c81c71SAlexander Shishkin put_device(dev); 3867bd1d409SAlexander Shishkin kfree(stmf); 3877bd1d409SAlexander Shishkin 3887bd1d409SAlexander Shishkin return err; 3897bd1d409SAlexander Shishkin } 3907bd1d409SAlexander Shishkin 3917bd1d409SAlexander Shishkin static int stm_char_release(struct inode *inode, struct file *file) 3927bd1d409SAlexander Shishkin { 3937bd1d409SAlexander Shishkin struct stm_file *stmf = file->private_data; 394cc842407SAlexander Shishkin struct stm_device *stm = stmf->stm; 3957bd1d409SAlexander Shishkin 396cc842407SAlexander Shishkin if (stm->data->unlink) 397cc842407SAlexander Shishkin stm->data->unlink(stm->data, stmf->output.master, 398cc842407SAlexander Shishkin stmf->output.channel); 399cc842407SAlexander Shishkin 400cc842407SAlexander Shishkin stm_output_free(stm, &stmf->output); 401f7c81c71SAlexander Shishkin 402f7c81c71SAlexander Shishkin /* 403f7c81c71SAlexander Shishkin * matches the stm_char_open()'s 404f7c81c71SAlexander Shishkin * class_find_device() + try_module_get() 405f7c81c71SAlexander Shishkin */ 406cc842407SAlexander Shishkin stm_put_device(stm); 4077bd1d409SAlexander Shishkin kfree(stmf); 4087bd1d409SAlexander Shishkin 4097bd1d409SAlexander Shishkin return 0; 4107bd1d409SAlexander Shishkin } 4117bd1d409SAlexander Shishkin 4127bd1d409SAlexander Shishkin static int stm_file_assign(struct stm_file *stmf, char *id, unsigned int width) 4137bd1d409SAlexander Shishkin { 4147bd1d409SAlexander Shishkin struct stm_device *stm = stmf->stm; 4157bd1d409SAlexander Shishkin int ret; 4167bd1d409SAlexander Shishkin 4177bd1d409SAlexander Shishkin stmf->policy_node = stp_policy_node_lookup(stm, id); 4187bd1d409SAlexander Shishkin 4197bd1d409SAlexander Shishkin ret = stm_output_assign(stm, width, stmf->policy_node, &stmf->output); 4207bd1d409SAlexander Shishkin 4217bd1d409SAlexander Shishkin if (stmf->policy_node) 4227bd1d409SAlexander Shishkin stp_policy_node_put(stmf->policy_node); 4237bd1d409SAlexander Shishkin 4247bd1d409SAlexander Shishkin return ret; 4257bd1d409SAlexander Shishkin } 4267bd1d409SAlexander Shishkin 427f8560a9bSAlexander Shishkin static ssize_t stm_write(struct stm_data *data, unsigned int master, 4287bd1d409SAlexander Shishkin unsigned int channel, const char *buf, size_t count) 4297bd1d409SAlexander Shishkin { 4307bd1d409SAlexander Shishkin unsigned int flags = STP_PACKET_TIMESTAMPED; 4317bd1d409SAlexander Shishkin const unsigned char *p = buf, nil = 0; 4327bd1d409SAlexander Shishkin size_t pos; 4337bd1d409SAlexander Shishkin ssize_t sz; 4347bd1d409SAlexander Shishkin 4357bd1d409SAlexander Shishkin for (pos = 0, p = buf; count > pos; pos += sz, p += sz) { 4367bd1d409SAlexander Shishkin sz = min_t(unsigned int, count - pos, 8); 4377bd1d409SAlexander Shishkin sz = data->packet(data, master, channel, STP_PACKET_DATA, flags, 4387bd1d409SAlexander Shishkin sz, p); 4397bd1d409SAlexander Shishkin flags = 0; 440f8560a9bSAlexander Shishkin 441f8560a9bSAlexander Shishkin if (sz < 0) 442f8560a9bSAlexander Shishkin break; 4437bd1d409SAlexander Shishkin } 4447bd1d409SAlexander Shishkin 4457bd1d409SAlexander Shishkin data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, &nil); 446f8560a9bSAlexander Shishkin 447f8560a9bSAlexander Shishkin return pos; 4487bd1d409SAlexander Shishkin } 4497bd1d409SAlexander Shishkin 4507bd1d409SAlexander Shishkin static ssize_t stm_char_write(struct file *file, const char __user *buf, 4517bd1d409SAlexander Shishkin size_t count, loff_t *ppos) 4527bd1d409SAlexander Shishkin { 4537bd1d409SAlexander Shishkin struct stm_file *stmf = file->private_data; 4547bd1d409SAlexander Shishkin struct stm_device *stm = stmf->stm; 4557bd1d409SAlexander Shishkin char *kbuf; 4567bd1d409SAlexander Shishkin int err; 4577bd1d409SAlexander Shishkin 458f08b1826SAlexander Shishkin if (count + 1 > PAGE_SIZE) 459f08b1826SAlexander Shishkin count = PAGE_SIZE - 1; 460f08b1826SAlexander Shishkin 4617bd1d409SAlexander Shishkin /* 4627bd1d409SAlexander Shishkin * if no m/c have been assigned to this writer up to this 4637bd1d409SAlexander Shishkin * point, use "default" policy entry 4647bd1d409SAlexander Shishkin */ 4657bd1d409SAlexander Shishkin if (!stmf->output.nr_chans) { 4667bd1d409SAlexander Shishkin err = stm_file_assign(stmf, "default", 1); 4677bd1d409SAlexander Shishkin /* 4687bd1d409SAlexander Shishkin * EBUSY means that somebody else just assigned this 4697bd1d409SAlexander Shishkin * output, which is just fine for write() 4707bd1d409SAlexander Shishkin */ 4717bd1d409SAlexander Shishkin if (err && err != -EBUSY) 4727bd1d409SAlexander Shishkin return err; 4737bd1d409SAlexander Shishkin } 4747bd1d409SAlexander Shishkin 4757bd1d409SAlexander Shishkin kbuf = kmalloc(count + 1, GFP_KERNEL); 4767bd1d409SAlexander Shishkin if (!kbuf) 4777bd1d409SAlexander Shishkin return -ENOMEM; 4787bd1d409SAlexander Shishkin 4797bd1d409SAlexander Shishkin err = copy_from_user(kbuf, buf, count); 4807bd1d409SAlexander Shishkin if (err) { 4817bd1d409SAlexander Shishkin kfree(kbuf); 4827bd1d409SAlexander Shishkin return -EFAULT; 4837bd1d409SAlexander Shishkin } 4847bd1d409SAlexander Shishkin 485f8560a9bSAlexander Shishkin count = stm_write(stm->data, stmf->output.master, stmf->output.channel, 486f8560a9bSAlexander Shishkin kbuf, count); 4877bd1d409SAlexander Shishkin 4887bd1d409SAlexander Shishkin kfree(kbuf); 4897bd1d409SAlexander Shishkin 4907bd1d409SAlexander Shishkin return count; 4917bd1d409SAlexander Shishkin } 4927bd1d409SAlexander Shishkin 4937bd1d409SAlexander Shishkin static int stm_char_mmap(struct file *file, struct vm_area_struct *vma) 4947bd1d409SAlexander Shishkin { 4957bd1d409SAlexander Shishkin struct stm_file *stmf = file->private_data; 4967bd1d409SAlexander Shishkin struct stm_device *stm = stmf->stm; 4977bd1d409SAlexander Shishkin unsigned long size, phys; 4987bd1d409SAlexander Shishkin 4997bd1d409SAlexander Shishkin if (!stm->data->mmio_addr) 5007bd1d409SAlexander Shishkin return -EOPNOTSUPP; 5017bd1d409SAlexander Shishkin 5027bd1d409SAlexander Shishkin if (vma->vm_pgoff) 5037bd1d409SAlexander Shishkin return -EINVAL; 5047bd1d409SAlexander Shishkin 5057bd1d409SAlexander Shishkin size = vma->vm_end - vma->vm_start; 5067bd1d409SAlexander Shishkin 5077bd1d409SAlexander Shishkin if (stmf->output.nr_chans * stm->data->sw_mmiosz != size) 5087bd1d409SAlexander Shishkin return -EINVAL; 5097bd1d409SAlexander Shishkin 5107bd1d409SAlexander Shishkin phys = stm->data->mmio_addr(stm->data, stmf->output.master, 5117bd1d409SAlexander Shishkin stmf->output.channel, 5127bd1d409SAlexander Shishkin stmf->output.nr_chans); 5137bd1d409SAlexander Shishkin 5147bd1d409SAlexander Shishkin if (!phys) 5157bd1d409SAlexander Shishkin return -EINVAL; 5167bd1d409SAlexander Shishkin 5177bd1d409SAlexander Shishkin vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 5187bd1d409SAlexander Shishkin vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; 5197bd1d409SAlexander Shishkin vm_iomap_memory(vma, phys, size); 5207bd1d409SAlexander Shishkin 5217bd1d409SAlexander Shishkin return 0; 5227bd1d409SAlexander Shishkin } 5237bd1d409SAlexander Shishkin 5247bd1d409SAlexander Shishkin static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg) 5257bd1d409SAlexander Shishkin { 5267bd1d409SAlexander Shishkin struct stm_device *stm = stmf->stm; 5277bd1d409SAlexander Shishkin struct stp_policy_id *id; 5287bd1d409SAlexander Shishkin int ret = -EINVAL; 5297bd1d409SAlexander Shishkin u32 size; 5307bd1d409SAlexander Shishkin 5317bd1d409SAlexander Shishkin if (stmf->output.nr_chans) 5327bd1d409SAlexander Shishkin return -EBUSY; 5337bd1d409SAlexander Shishkin 5347bd1d409SAlexander Shishkin if (copy_from_user(&size, arg, sizeof(size))) 5357bd1d409SAlexander Shishkin return -EFAULT; 5367bd1d409SAlexander Shishkin 5377bd1d409SAlexander Shishkin if (size >= PATH_MAX + sizeof(*id)) 5387bd1d409SAlexander Shishkin return -EINVAL; 5397bd1d409SAlexander Shishkin 5407bd1d409SAlexander Shishkin /* 5417bd1d409SAlexander Shishkin * size + 1 to make sure the .id string at the bottom is terminated, 5427bd1d409SAlexander Shishkin * which is also why memdup_user() is not useful here 5437bd1d409SAlexander Shishkin */ 5447bd1d409SAlexander Shishkin id = kzalloc(size + 1, GFP_KERNEL); 5457bd1d409SAlexander Shishkin if (!id) 5467bd1d409SAlexander Shishkin return -ENOMEM; 5477bd1d409SAlexander Shishkin 5487bd1d409SAlexander Shishkin if (copy_from_user(id, arg, size)) { 5497bd1d409SAlexander Shishkin ret = -EFAULT; 5507bd1d409SAlexander Shishkin goto err_free; 5517bd1d409SAlexander Shishkin } 5527bd1d409SAlexander Shishkin 5537bd1d409SAlexander Shishkin if (id->__reserved_0 || id->__reserved_1) 5547bd1d409SAlexander Shishkin goto err_free; 5557bd1d409SAlexander Shishkin 5567bd1d409SAlexander Shishkin if (id->width < 1 || 5577bd1d409SAlexander Shishkin id->width > PAGE_SIZE / stm->data->sw_mmiosz) 5587bd1d409SAlexander Shishkin goto err_free; 5597bd1d409SAlexander Shishkin 5607bd1d409SAlexander Shishkin ret = stm_file_assign(stmf, id->id, id->width); 5617bd1d409SAlexander Shishkin if (ret) 5627bd1d409SAlexander Shishkin goto err_free; 5637bd1d409SAlexander Shishkin 5647bd1d409SAlexander Shishkin if (stm->data->link) 5657bd1d409SAlexander Shishkin ret = stm->data->link(stm->data, stmf->output.master, 5667bd1d409SAlexander Shishkin stmf->output.channel); 5677bd1d409SAlexander Shishkin 568f7c81c71SAlexander Shishkin if (ret) 5697bd1d409SAlexander Shishkin stm_output_free(stmf->stm, &stmf->output); 5707bd1d409SAlexander Shishkin 5717bd1d409SAlexander Shishkin err_free: 5727bd1d409SAlexander Shishkin kfree(id); 5737bd1d409SAlexander Shishkin 5747bd1d409SAlexander Shishkin return ret; 5757bd1d409SAlexander Shishkin } 5767bd1d409SAlexander Shishkin 5777bd1d409SAlexander Shishkin static int stm_char_policy_get_ioctl(struct stm_file *stmf, void __user *arg) 5787bd1d409SAlexander Shishkin { 5797bd1d409SAlexander Shishkin struct stp_policy_id id = { 5807bd1d409SAlexander Shishkin .size = sizeof(id), 5817bd1d409SAlexander Shishkin .master = stmf->output.master, 5827bd1d409SAlexander Shishkin .channel = stmf->output.channel, 5837bd1d409SAlexander Shishkin .width = stmf->output.nr_chans, 5847bd1d409SAlexander Shishkin .__reserved_0 = 0, 5857bd1d409SAlexander Shishkin .__reserved_1 = 0, 5867bd1d409SAlexander Shishkin }; 5877bd1d409SAlexander Shishkin 5887bd1d409SAlexander Shishkin return copy_to_user(arg, &id, id.size) ? -EFAULT : 0; 5897bd1d409SAlexander Shishkin } 5907bd1d409SAlexander Shishkin 5917bd1d409SAlexander Shishkin static long 5927bd1d409SAlexander Shishkin stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 5937bd1d409SAlexander Shishkin { 5947bd1d409SAlexander Shishkin struct stm_file *stmf = file->private_data; 5957bd1d409SAlexander Shishkin struct stm_data *stm_data = stmf->stm->data; 5967bd1d409SAlexander Shishkin int err = -ENOTTY; 5977bd1d409SAlexander Shishkin u64 options; 5987bd1d409SAlexander Shishkin 5997bd1d409SAlexander Shishkin switch (cmd) { 6007bd1d409SAlexander Shishkin case STP_POLICY_ID_SET: 6017bd1d409SAlexander Shishkin err = stm_char_policy_set_ioctl(stmf, (void __user *)arg); 6027bd1d409SAlexander Shishkin if (err) 6037bd1d409SAlexander Shishkin return err; 6047bd1d409SAlexander Shishkin 6057bd1d409SAlexander Shishkin return stm_char_policy_get_ioctl(stmf, (void __user *)arg); 6067bd1d409SAlexander Shishkin 6077bd1d409SAlexander Shishkin case STP_POLICY_ID_GET: 6087bd1d409SAlexander Shishkin return stm_char_policy_get_ioctl(stmf, (void __user *)arg); 6097bd1d409SAlexander Shishkin 6107bd1d409SAlexander Shishkin case STP_SET_OPTIONS: 6117bd1d409SAlexander Shishkin if (copy_from_user(&options, (u64 __user *)arg, sizeof(u64))) 6127bd1d409SAlexander Shishkin return -EFAULT; 6137bd1d409SAlexander Shishkin 6147bd1d409SAlexander Shishkin if (stm_data->set_options) 6157bd1d409SAlexander Shishkin err = stm_data->set_options(stm_data, 6167bd1d409SAlexander Shishkin stmf->output.master, 6177bd1d409SAlexander Shishkin stmf->output.channel, 6187bd1d409SAlexander Shishkin stmf->output.nr_chans, 6197bd1d409SAlexander Shishkin options); 6207bd1d409SAlexander Shishkin 6217bd1d409SAlexander Shishkin break; 6227bd1d409SAlexander Shishkin default: 6237bd1d409SAlexander Shishkin break; 6247bd1d409SAlexander Shishkin } 6257bd1d409SAlexander Shishkin 6267bd1d409SAlexander Shishkin return err; 6277bd1d409SAlexander Shishkin } 6287bd1d409SAlexander Shishkin 6297bd1d409SAlexander Shishkin #ifdef CONFIG_COMPAT 6307bd1d409SAlexander Shishkin static long 6317bd1d409SAlexander Shishkin stm_char_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 6327bd1d409SAlexander Shishkin { 6337bd1d409SAlexander Shishkin return stm_char_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 6347bd1d409SAlexander Shishkin } 6357bd1d409SAlexander Shishkin #else 6367bd1d409SAlexander Shishkin #define stm_char_compat_ioctl NULL 6377bd1d409SAlexander Shishkin #endif 6387bd1d409SAlexander Shishkin 6397bd1d409SAlexander Shishkin static const struct file_operations stm_fops = { 6407bd1d409SAlexander Shishkin .open = stm_char_open, 6417bd1d409SAlexander Shishkin .release = stm_char_release, 6427bd1d409SAlexander Shishkin .write = stm_char_write, 6437bd1d409SAlexander Shishkin .mmap = stm_char_mmap, 6447bd1d409SAlexander Shishkin .unlocked_ioctl = stm_char_ioctl, 6457bd1d409SAlexander Shishkin .compat_ioctl = stm_char_compat_ioctl, 6467bd1d409SAlexander Shishkin .llseek = no_llseek, 6477bd1d409SAlexander Shishkin }; 6487bd1d409SAlexander Shishkin 6497bd1d409SAlexander Shishkin static void stm_device_release(struct device *dev) 6507bd1d409SAlexander Shishkin { 6517bd1d409SAlexander Shishkin struct stm_device *stm = to_stm_device(dev); 6527bd1d409SAlexander Shishkin 6537bd1d409SAlexander Shishkin kfree(stm); 6547bd1d409SAlexander Shishkin } 6557bd1d409SAlexander Shishkin 6567bd1d409SAlexander Shishkin int stm_register_device(struct device *parent, struct stm_data *stm_data, 6577bd1d409SAlexander Shishkin struct module *owner) 6587bd1d409SAlexander Shishkin { 6597bd1d409SAlexander Shishkin struct stm_device *stm; 6607bd1d409SAlexander Shishkin unsigned int nmasters; 6617bd1d409SAlexander Shishkin int err = -ENOMEM; 6627bd1d409SAlexander Shishkin 6637bd1d409SAlexander Shishkin if (!stm_core_up) 6647bd1d409SAlexander Shishkin return -EPROBE_DEFER; 6657bd1d409SAlexander Shishkin 6667bd1d409SAlexander Shishkin if (!stm_data->packet || !stm_data->sw_nchannels) 6677bd1d409SAlexander Shishkin return -EINVAL; 6687bd1d409SAlexander Shishkin 6697b3bb0e7SChunyan Zhang nmasters = stm_data->sw_end - stm_data->sw_start + 1; 6707bd1d409SAlexander Shishkin stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL); 6717bd1d409SAlexander Shishkin if (!stm) 6727bd1d409SAlexander Shishkin return -ENOMEM; 6737bd1d409SAlexander Shishkin 6747bd1d409SAlexander Shishkin stm->major = register_chrdev(0, stm_data->name, &stm_fops); 6757bd1d409SAlexander Shishkin if (stm->major < 0) 6767bd1d409SAlexander Shishkin goto err_free; 6777bd1d409SAlexander Shishkin 6787bd1d409SAlexander Shishkin device_initialize(&stm->dev); 6797bd1d409SAlexander Shishkin stm->dev.devt = MKDEV(stm->major, 0); 6807bd1d409SAlexander Shishkin stm->dev.class = &stm_class; 6817bd1d409SAlexander Shishkin stm->dev.parent = parent; 6827bd1d409SAlexander Shishkin stm->dev.release = stm_device_release; 6837bd1d409SAlexander Shishkin 684389b6699SAlexander Shishkin mutex_init(&stm->link_mutex); 685389b6699SAlexander Shishkin spin_lock_init(&stm->link_lock); 686389b6699SAlexander Shishkin INIT_LIST_HEAD(&stm->link_list); 687389b6699SAlexander Shishkin 688389b6699SAlexander Shishkin /* initialize the object before it is accessible via sysfs */ 689389b6699SAlexander Shishkin spin_lock_init(&stm->mc_lock); 690389b6699SAlexander Shishkin mutex_init(&stm->policy_mutex); 691389b6699SAlexander Shishkin stm->sw_nmasters = nmasters; 692389b6699SAlexander Shishkin stm->owner = owner; 693389b6699SAlexander Shishkin stm->data = stm_data; 694389b6699SAlexander Shishkin stm_data->stm = stm; 695389b6699SAlexander Shishkin 6967bd1d409SAlexander Shishkin err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name); 6977bd1d409SAlexander Shishkin if (err) 6987bd1d409SAlexander Shishkin goto err_device; 6997bd1d409SAlexander Shishkin 7007bd1d409SAlexander Shishkin err = device_add(&stm->dev); 7017bd1d409SAlexander Shishkin if (err) 7027bd1d409SAlexander Shishkin goto err_device; 7037bd1d409SAlexander Shishkin 7047bd1d409SAlexander Shishkin return 0; 7057bd1d409SAlexander Shishkin 7067bd1d409SAlexander Shishkin err_device: 707cbe4a61dSAlexander Shishkin unregister_chrdev(stm->major, stm_data->name); 708cbe4a61dSAlexander Shishkin 709f7c81c71SAlexander Shishkin /* matches device_initialize() above */ 7107bd1d409SAlexander Shishkin put_device(&stm->dev); 7117bd1d409SAlexander Shishkin err_free: 7127bd1d409SAlexander Shishkin kfree(stm); 7137bd1d409SAlexander Shishkin 7147bd1d409SAlexander Shishkin return err; 7157bd1d409SAlexander Shishkin } 7167bd1d409SAlexander Shishkin EXPORT_SYMBOL_GPL(stm_register_device); 7177bd1d409SAlexander Shishkin 718b4ca34aaSAlexander Shishkin static int __stm_source_link_drop(struct stm_source_device *src, 7197bd1d409SAlexander Shishkin struct stm_device *stm); 7207bd1d409SAlexander Shishkin 7217bd1d409SAlexander Shishkin void stm_unregister_device(struct stm_data *stm_data) 7227bd1d409SAlexander Shishkin { 7237bd1d409SAlexander Shishkin struct stm_device *stm = stm_data->stm; 7247bd1d409SAlexander Shishkin struct stm_source_device *src, *iter; 725b4ca34aaSAlexander Shishkin int i, ret; 7267bd1d409SAlexander Shishkin 727c74f7e82SAlexander Shishkin mutex_lock(&stm->link_mutex); 7287bd1d409SAlexander Shishkin list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) { 729b4ca34aaSAlexander Shishkin ret = __stm_source_link_drop(src, stm); 730b4ca34aaSAlexander Shishkin /* 731b4ca34aaSAlexander Shishkin * src <-> stm link must not change under the same 732b4ca34aaSAlexander Shishkin * stm::link_mutex, so complain loudly if it has; 733b4ca34aaSAlexander Shishkin * also in this situation ret!=0 means this src is 734b4ca34aaSAlexander Shishkin * not connected to this stm and it should be otherwise 735b4ca34aaSAlexander Shishkin * safe to proceed with the tear-down of stm. 736b4ca34aaSAlexander Shishkin */ 737b4ca34aaSAlexander Shishkin WARN_ON_ONCE(ret); 7387bd1d409SAlexander Shishkin } 739c74f7e82SAlexander Shishkin mutex_unlock(&stm->link_mutex); 7407bd1d409SAlexander Shishkin 7417bd1d409SAlexander Shishkin synchronize_srcu(&stm_source_srcu); 7427bd1d409SAlexander Shishkin 7437bd1d409SAlexander Shishkin unregister_chrdev(stm->major, stm_data->name); 7447bd1d409SAlexander Shishkin 7457bd1d409SAlexander Shishkin mutex_lock(&stm->policy_mutex); 7467bd1d409SAlexander Shishkin if (stm->policy) 7477bd1d409SAlexander Shishkin stp_policy_unbind(stm->policy); 7487bd1d409SAlexander Shishkin mutex_unlock(&stm->policy_mutex); 7497bd1d409SAlexander Shishkin 75073a3ed19SChunyan Zhang for (i = stm->data->sw_start; i <= stm->data->sw_end; i++) 7517bd1d409SAlexander Shishkin stp_master_free(stm, i); 7527bd1d409SAlexander Shishkin 7537bd1d409SAlexander Shishkin device_unregister(&stm->dev); 7547bd1d409SAlexander Shishkin stm_data->stm = NULL; 7557bd1d409SAlexander Shishkin } 7567bd1d409SAlexander Shishkin EXPORT_SYMBOL_GPL(stm_unregister_device); 7577bd1d409SAlexander Shishkin 758c74f7e82SAlexander Shishkin /* 759c74f7e82SAlexander Shishkin * stm::link_list access serialization uses a spinlock and a mutex; holding 760c74f7e82SAlexander Shishkin * either of them guarantees that the list is stable; modification requires 761c74f7e82SAlexander Shishkin * holding both of them. 762c74f7e82SAlexander Shishkin * 763c74f7e82SAlexander Shishkin * Lock ordering is as follows: 764c74f7e82SAlexander Shishkin * stm::link_mutex 765c74f7e82SAlexander Shishkin * stm::link_lock 766c74f7e82SAlexander Shishkin * src::link_lock 767c74f7e82SAlexander Shishkin */ 768c74f7e82SAlexander Shishkin 7697bd1d409SAlexander Shishkin /** 7707bd1d409SAlexander Shishkin * stm_source_link_add() - connect an stm_source device to an stm device 7717bd1d409SAlexander Shishkin * @src: stm_source device 7727bd1d409SAlexander Shishkin * @stm: stm device 7737bd1d409SAlexander Shishkin * 7747bd1d409SAlexander Shishkin * This function establishes a link from stm_source to an stm device so that 7757bd1d409SAlexander Shishkin * the former can send out trace data to the latter. 7767bd1d409SAlexander Shishkin * 7777bd1d409SAlexander Shishkin * Return: 0 on success, -errno otherwise. 7787bd1d409SAlexander Shishkin */ 7797bd1d409SAlexander Shishkin static int stm_source_link_add(struct stm_source_device *src, 7807bd1d409SAlexander Shishkin struct stm_device *stm) 7817bd1d409SAlexander Shishkin { 7827bd1d409SAlexander Shishkin char *id; 7837bd1d409SAlexander Shishkin int err; 7847bd1d409SAlexander Shishkin 785c74f7e82SAlexander Shishkin mutex_lock(&stm->link_mutex); 7867bd1d409SAlexander Shishkin spin_lock(&stm->link_lock); 7877bd1d409SAlexander Shishkin spin_lock(&src->link_lock); 7887bd1d409SAlexander Shishkin 7897bd1d409SAlexander Shishkin /* src->link is dereferenced under stm_source_srcu but not the list */ 7907bd1d409SAlexander Shishkin rcu_assign_pointer(src->link, stm); 7917bd1d409SAlexander Shishkin list_add_tail(&src->link_entry, &stm->link_list); 7927bd1d409SAlexander Shishkin 7937bd1d409SAlexander Shishkin spin_unlock(&src->link_lock); 7947bd1d409SAlexander Shishkin spin_unlock(&stm->link_lock); 795c74f7e82SAlexander Shishkin mutex_unlock(&stm->link_mutex); 7967bd1d409SAlexander Shishkin 7977bd1d409SAlexander Shishkin id = kstrdup(src->data->name, GFP_KERNEL); 7987bd1d409SAlexander Shishkin if (id) { 7997bd1d409SAlexander Shishkin src->policy_node = 8007bd1d409SAlexander Shishkin stp_policy_node_lookup(stm, id); 8017bd1d409SAlexander Shishkin 8027bd1d409SAlexander Shishkin kfree(id); 8037bd1d409SAlexander Shishkin } 8047bd1d409SAlexander Shishkin 8057bd1d409SAlexander Shishkin err = stm_output_assign(stm, src->data->nr_chans, 8067bd1d409SAlexander Shishkin src->policy_node, &src->output); 8077bd1d409SAlexander Shishkin 8087bd1d409SAlexander Shishkin if (src->policy_node) 8097bd1d409SAlexander Shishkin stp_policy_node_put(src->policy_node); 8107bd1d409SAlexander Shishkin 8117bd1d409SAlexander Shishkin if (err) 8127bd1d409SAlexander Shishkin goto fail_detach; 8137bd1d409SAlexander Shishkin 8147bd1d409SAlexander Shishkin /* this is to notify the STM device that a new link has been made */ 8157bd1d409SAlexander Shishkin if (stm->data->link) 8167bd1d409SAlexander Shishkin err = stm->data->link(stm->data, src->output.master, 8177bd1d409SAlexander Shishkin src->output.channel); 8187bd1d409SAlexander Shishkin 8197bd1d409SAlexander Shishkin if (err) 8207bd1d409SAlexander Shishkin goto fail_free_output; 8217bd1d409SAlexander Shishkin 8227bd1d409SAlexander Shishkin /* this is to let the source carry out all necessary preparations */ 8237bd1d409SAlexander Shishkin if (src->data->link) 8247bd1d409SAlexander Shishkin src->data->link(src->data); 8257bd1d409SAlexander Shishkin 8267bd1d409SAlexander Shishkin return 0; 8277bd1d409SAlexander Shishkin 8287bd1d409SAlexander Shishkin fail_free_output: 8297bd1d409SAlexander Shishkin stm_output_free(stm, &src->output); 8307bd1d409SAlexander Shishkin 8317bd1d409SAlexander Shishkin fail_detach: 832c74f7e82SAlexander Shishkin mutex_lock(&stm->link_mutex); 8337bd1d409SAlexander Shishkin spin_lock(&stm->link_lock); 8347bd1d409SAlexander Shishkin spin_lock(&src->link_lock); 8357bd1d409SAlexander Shishkin 8367bd1d409SAlexander Shishkin rcu_assign_pointer(src->link, NULL); 8377bd1d409SAlexander Shishkin list_del_init(&src->link_entry); 8387bd1d409SAlexander Shishkin 8397bd1d409SAlexander Shishkin spin_unlock(&src->link_lock); 8407bd1d409SAlexander Shishkin spin_unlock(&stm->link_lock); 841c74f7e82SAlexander Shishkin mutex_unlock(&stm->link_mutex); 8427bd1d409SAlexander Shishkin 8437bd1d409SAlexander Shishkin return err; 8447bd1d409SAlexander Shishkin } 8457bd1d409SAlexander Shishkin 8467bd1d409SAlexander Shishkin /** 8477bd1d409SAlexander Shishkin * __stm_source_link_drop() - detach stm_source from an stm device 8487bd1d409SAlexander Shishkin * @src: stm_source device 8497bd1d409SAlexander Shishkin * @stm: stm device 8507bd1d409SAlexander Shishkin * 8517bd1d409SAlexander Shishkin * If @stm is @src::link, disconnect them from one another and put the 8527bd1d409SAlexander Shishkin * reference on the @stm device. 8537bd1d409SAlexander Shishkin * 854c74f7e82SAlexander Shishkin * Caller must hold stm::link_mutex. 8557bd1d409SAlexander Shishkin */ 856b4ca34aaSAlexander Shishkin static int __stm_source_link_drop(struct stm_source_device *src, 8577bd1d409SAlexander Shishkin struct stm_device *stm) 8587bd1d409SAlexander Shishkin { 8590df771deSAlexander Shishkin struct stm_device *link; 860b4ca34aaSAlexander Shishkin int ret = 0; 8610df771deSAlexander Shishkin 862c74f7e82SAlexander Shishkin lockdep_assert_held(&stm->link_mutex); 863c74f7e82SAlexander Shishkin 864c74f7e82SAlexander Shishkin /* for stm::link_list modification, we hold both mutex and spinlock */ 865c74f7e82SAlexander Shishkin spin_lock(&stm->link_lock); 8667bd1d409SAlexander Shishkin spin_lock(&src->link_lock); 8670df771deSAlexander Shishkin link = srcu_dereference_check(src->link, &stm_source_srcu, 1); 868b4ca34aaSAlexander Shishkin 869b4ca34aaSAlexander Shishkin /* 870b4ca34aaSAlexander Shishkin * The linked device may have changed since we last looked, because 871b4ca34aaSAlexander Shishkin * we weren't holding the src::link_lock back then; if this is the 872b4ca34aaSAlexander Shishkin * case, tell the caller to retry. 873b4ca34aaSAlexander Shishkin */ 874b4ca34aaSAlexander Shishkin if (link != stm) { 875b4ca34aaSAlexander Shishkin ret = -EAGAIN; 8761810f2c4SAlexander Shishkin goto unlock; 877b4ca34aaSAlexander Shishkin } 8787bd1d409SAlexander Shishkin 8790df771deSAlexander Shishkin stm_output_free(link, &src->output); 8807bd1d409SAlexander Shishkin list_del_init(&src->link_entry); 8817bd1d409SAlexander Shishkin /* matches stm_find_device() from stm_source_link_store() */ 8820df771deSAlexander Shishkin stm_put_device(link); 8837bd1d409SAlexander Shishkin rcu_assign_pointer(src->link, NULL); 8847bd1d409SAlexander Shishkin 8851810f2c4SAlexander Shishkin unlock: 8867bd1d409SAlexander Shishkin spin_unlock(&src->link_lock); 887c74f7e82SAlexander Shishkin spin_unlock(&stm->link_lock); 888b4ca34aaSAlexander Shishkin 889cc842407SAlexander Shishkin /* 890cc842407SAlexander Shishkin * Call the unlink callbacks for both source and stm, when we know 891cc842407SAlexander Shishkin * that we have actually performed the unlinking. 892cc842407SAlexander Shishkin */ 893cc842407SAlexander Shishkin if (!ret) { 894cc842407SAlexander Shishkin if (src->data->unlink) 895b4ca34aaSAlexander Shishkin src->data->unlink(src->data); 896b4ca34aaSAlexander Shishkin 897cc842407SAlexander Shishkin if (stm->data->unlink) 898cc842407SAlexander Shishkin stm->data->unlink(stm->data, src->output.master, 899cc842407SAlexander Shishkin src->output.channel); 900cc842407SAlexander Shishkin } 901cc842407SAlexander Shishkin 902b4ca34aaSAlexander Shishkin return ret; 9037bd1d409SAlexander Shishkin } 9047bd1d409SAlexander Shishkin 9057bd1d409SAlexander Shishkin /** 9067bd1d409SAlexander Shishkin * stm_source_link_drop() - detach stm_source from its stm device 9077bd1d409SAlexander Shishkin * @src: stm_source device 9087bd1d409SAlexander Shishkin * 9097bd1d409SAlexander Shishkin * Unlinking means disconnecting from source's STM device; after this 9107bd1d409SAlexander Shishkin * writes will be unsuccessful until it is linked to a new STM device. 9117bd1d409SAlexander Shishkin * 9127bd1d409SAlexander Shishkin * This will happen on "stm_source_link" sysfs attribute write to undo 9137bd1d409SAlexander Shishkin * the existing link (if any), or on linked STM device's de-registration. 9147bd1d409SAlexander Shishkin */ 9157bd1d409SAlexander Shishkin static void stm_source_link_drop(struct stm_source_device *src) 9167bd1d409SAlexander Shishkin { 9177bd1d409SAlexander Shishkin struct stm_device *stm; 918b4ca34aaSAlexander Shishkin int idx, ret; 9197bd1d409SAlexander Shishkin 920b4ca34aaSAlexander Shishkin retry: 9217bd1d409SAlexander Shishkin idx = srcu_read_lock(&stm_source_srcu); 922b4ca34aaSAlexander Shishkin /* 923b4ca34aaSAlexander Shishkin * The stm device will be valid for the duration of this 924b4ca34aaSAlexander Shishkin * read section, but the link may change before we grab 925b4ca34aaSAlexander Shishkin * the src::link_lock in __stm_source_link_drop(). 926b4ca34aaSAlexander Shishkin */ 9277bd1d409SAlexander Shishkin stm = srcu_dereference(src->link, &stm_source_srcu); 9287bd1d409SAlexander Shishkin 929b4ca34aaSAlexander Shishkin ret = 0; 9307bd1d409SAlexander Shishkin if (stm) { 931c74f7e82SAlexander Shishkin mutex_lock(&stm->link_mutex); 932b4ca34aaSAlexander Shishkin ret = __stm_source_link_drop(src, stm); 933c74f7e82SAlexander Shishkin mutex_unlock(&stm->link_mutex); 9347bd1d409SAlexander Shishkin } 9357bd1d409SAlexander Shishkin 9367bd1d409SAlexander Shishkin srcu_read_unlock(&stm_source_srcu, idx); 937b4ca34aaSAlexander Shishkin 938b4ca34aaSAlexander Shishkin /* if it did change, retry */ 939b4ca34aaSAlexander Shishkin if (ret == -EAGAIN) 940b4ca34aaSAlexander Shishkin goto retry; 9417bd1d409SAlexander Shishkin } 9427bd1d409SAlexander Shishkin 9437bd1d409SAlexander Shishkin static ssize_t stm_source_link_show(struct device *dev, 9447bd1d409SAlexander Shishkin struct device_attribute *attr, 9457bd1d409SAlexander Shishkin char *buf) 9467bd1d409SAlexander Shishkin { 9477bd1d409SAlexander Shishkin struct stm_source_device *src = to_stm_source_device(dev); 9487bd1d409SAlexander Shishkin struct stm_device *stm; 9497bd1d409SAlexander Shishkin int idx, ret; 9507bd1d409SAlexander Shishkin 9517bd1d409SAlexander Shishkin idx = srcu_read_lock(&stm_source_srcu); 9527bd1d409SAlexander Shishkin stm = srcu_dereference(src->link, &stm_source_srcu); 9537bd1d409SAlexander Shishkin ret = sprintf(buf, "%s\n", 9547bd1d409SAlexander Shishkin stm ? dev_name(&stm->dev) : "<none>"); 9557bd1d409SAlexander Shishkin srcu_read_unlock(&stm_source_srcu, idx); 9567bd1d409SAlexander Shishkin 9577bd1d409SAlexander Shishkin return ret; 9587bd1d409SAlexander Shishkin } 9597bd1d409SAlexander Shishkin 9607bd1d409SAlexander Shishkin static ssize_t stm_source_link_store(struct device *dev, 9617bd1d409SAlexander Shishkin struct device_attribute *attr, 9627bd1d409SAlexander Shishkin const char *buf, size_t count) 9637bd1d409SAlexander Shishkin { 9647bd1d409SAlexander Shishkin struct stm_source_device *src = to_stm_source_device(dev); 9657bd1d409SAlexander Shishkin struct stm_device *link; 9667bd1d409SAlexander Shishkin int err; 9677bd1d409SAlexander Shishkin 9687bd1d409SAlexander Shishkin stm_source_link_drop(src); 9697bd1d409SAlexander Shishkin 9707bd1d409SAlexander Shishkin link = stm_find_device(buf); 9717bd1d409SAlexander Shishkin if (!link) 9727bd1d409SAlexander Shishkin return -EINVAL; 9737bd1d409SAlexander Shishkin 9747bd1d409SAlexander Shishkin err = stm_source_link_add(src, link); 975f7c81c71SAlexander Shishkin if (err) { 976f7c81c71SAlexander Shishkin /* matches the stm_find_device() above */ 9777bd1d409SAlexander Shishkin stm_put_device(link); 978f7c81c71SAlexander Shishkin } 9797bd1d409SAlexander Shishkin 9807bd1d409SAlexander Shishkin return err ? : count; 9817bd1d409SAlexander Shishkin } 9827bd1d409SAlexander Shishkin 9837bd1d409SAlexander Shishkin static DEVICE_ATTR_RW(stm_source_link); 9847bd1d409SAlexander Shishkin 9857bd1d409SAlexander Shishkin static struct attribute *stm_source_attrs[] = { 9867bd1d409SAlexander Shishkin &dev_attr_stm_source_link.attr, 9877bd1d409SAlexander Shishkin NULL, 9887bd1d409SAlexander Shishkin }; 9897bd1d409SAlexander Shishkin 9907bd1d409SAlexander Shishkin ATTRIBUTE_GROUPS(stm_source); 9917bd1d409SAlexander Shishkin 9927bd1d409SAlexander Shishkin static struct class stm_source_class = { 9937bd1d409SAlexander Shishkin .name = "stm_source", 9947bd1d409SAlexander Shishkin .dev_groups = stm_source_groups, 9957bd1d409SAlexander Shishkin }; 9967bd1d409SAlexander Shishkin 9977bd1d409SAlexander Shishkin static void stm_source_device_release(struct device *dev) 9987bd1d409SAlexander Shishkin { 9997bd1d409SAlexander Shishkin struct stm_source_device *src = to_stm_source_device(dev); 10007bd1d409SAlexander Shishkin 10017bd1d409SAlexander Shishkin kfree(src); 10027bd1d409SAlexander Shishkin } 10037bd1d409SAlexander Shishkin 10047bd1d409SAlexander Shishkin /** 10057bd1d409SAlexander Shishkin * stm_source_register_device() - register an stm_source device 10067bd1d409SAlexander Shishkin * @parent: parent device 10077bd1d409SAlexander Shishkin * @data: device description structure 10087bd1d409SAlexander Shishkin * 10097bd1d409SAlexander Shishkin * This will create a device of stm_source class that can write 10107bd1d409SAlexander Shishkin * data to an stm device once linked. 10117bd1d409SAlexander Shishkin * 10127bd1d409SAlexander Shishkin * Return: 0 on success, -errno otherwise. 10137bd1d409SAlexander Shishkin */ 10147bd1d409SAlexander Shishkin int stm_source_register_device(struct device *parent, 10157bd1d409SAlexander Shishkin struct stm_source_data *data) 10167bd1d409SAlexander Shishkin { 10177bd1d409SAlexander Shishkin struct stm_source_device *src; 10187bd1d409SAlexander Shishkin int err; 10197bd1d409SAlexander Shishkin 10207bd1d409SAlexander Shishkin if (!stm_core_up) 10217bd1d409SAlexander Shishkin return -EPROBE_DEFER; 10227bd1d409SAlexander Shishkin 10237bd1d409SAlexander Shishkin src = kzalloc(sizeof(*src), GFP_KERNEL); 10247bd1d409SAlexander Shishkin if (!src) 10257bd1d409SAlexander Shishkin return -ENOMEM; 10267bd1d409SAlexander Shishkin 10277bd1d409SAlexander Shishkin device_initialize(&src->dev); 10287bd1d409SAlexander Shishkin src->dev.class = &stm_source_class; 10297bd1d409SAlexander Shishkin src->dev.parent = parent; 10307bd1d409SAlexander Shishkin src->dev.release = stm_source_device_release; 10317bd1d409SAlexander Shishkin 10327bd1d409SAlexander Shishkin err = kobject_set_name(&src->dev.kobj, "%s", data->name); 10337bd1d409SAlexander Shishkin if (err) 10347bd1d409SAlexander Shishkin goto err; 10357bd1d409SAlexander Shishkin 10367bd1d409SAlexander Shishkin err = device_add(&src->dev); 10377bd1d409SAlexander Shishkin if (err) 10387bd1d409SAlexander Shishkin goto err; 10397bd1d409SAlexander Shishkin 1040cde4ad83SAlexander Shishkin stm_output_init(&src->output); 10417bd1d409SAlexander Shishkin spin_lock_init(&src->link_lock); 10427bd1d409SAlexander Shishkin INIT_LIST_HEAD(&src->link_entry); 10437bd1d409SAlexander Shishkin src->data = data; 10447bd1d409SAlexander Shishkin data->src = src; 10457bd1d409SAlexander Shishkin 10467bd1d409SAlexander Shishkin return 0; 10477bd1d409SAlexander Shishkin 10487bd1d409SAlexander Shishkin err: 10497bd1d409SAlexander Shishkin put_device(&src->dev); 10507bd1d409SAlexander Shishkin kfree(src); 10517bd1d409SAlexander Shishkin 10527bd1d409SAlexander Shishkin return err; 10537bd1d409SAlexander Shishkin } 10547bd1d409SAlexander Shishkin EXPORT_SYMBOL_GPL(stm_source_register_device); 10557bd1d409SAlexander Shishkin 10567bd1d409SAlexander Shishkin /** 10577bd1d409SAlexander Shishkin * stm_source_unregister_device() - unregister an stm_source device 10587bd1d409SAlexander Shishkin * @data: device description that was used to register the device 10597bd1d409SAlexander Shishkin * 10607bd1d409SAlexander Shishkin * This will remove a previously created stm_source device from the system. 10617bd1d409SAlexander Shishkin */ 10627bd1d409SAlexander Shishkin void stm_source_unregister_device(struct stm_source_data *data) 10637bd1d409SAlexander Shishkin { 10647bd1d409SAlexander Shishkin struct stm_source_device *src = data->src; 10657bd1d409SAlexander Shishkin 10667bd1d409SAlexander Shishkin stm_source_link_drop(src); 10677bd1d409SAlexander Shishkin 10687bd1d409SAlexander Shishkin device_destroy(&stm_source_class, src->dev.devt); 10697bd1d409SAlexander Shishkin } 10707bd1d409SAlexander Shishkin EXPORT_SYMBOL_GPL(stm_source_unregister_device); 10717bd1d409SAlexander Shishkin 10727bd1d409SAlexander Shishkin int stm_source_write(struct stm_source_data *data, unsigned int chan, 10737bd1d409SAlexander Shishkin const char *buf, size_t count) 10747bd1d409SAlexander Shishkin { 10757bd1d409SAlexander Shishkin struct stm_source_device *src = data->src; 10767bd1d409SAlexander Shishkin struct stm_device *stm; 10777bd1d409SAlexander Shishkin int idx; 10787bd1d409SAlexander Shishkin 10797bd1d409SAlexander Shishkin if (!src->output.nr_chans) 10807bd1d409SAlexander Shishkin return -ENODEV; 10817bd1d409SAlexander Shishkin 10827bd1d409SAlexander Shishkin if (chan >= src->output.nr_chans) 10837bd1d409SAlexander Shishkin return -EINVAL; 10847bd1d409SAlexander Shishkin 10857bd1d409SAlexander Shishkin idx = srcu_read_lock(&stm_source_srcu); 10867bd1d409SAlexander Shishkin 10877bd1d409SAlexander Shishkin stm = srcu_dereference(src->link, &stm_source_srcu); 10887bd1d409SAlexander Shishkin if (stm) 1089f8560a9bSAlexander Shishkin count = stm_write(stm->data, src->output.master, 10907bd1d409SAlexander Shishkin src->output.channel + chan, 10917bd1d409SAlexander Shishkin buf, count); 10927bd1d409SAlexander Shishkin else 10937bd1d409SAlexander Shishkin count = -ENODEV; 10947bd1d409SAlexander Shishkin 10957bd1d409SAlexander Shishkin srcu_read_unlock(&stm_source_srcu, idx); 10967bd1d409SAlexander Shishkin 10977bd1d409SAlexander Shishkin return count; 10987bd1d409SAlexander Shishkin } 10997bd1d409SAlexander Shishkin EXPORT_SYMBOL_GPL(stm_source_write); 11007bd1d409SAlexander Shishkin 11017bd1d409SAlexander Shishkin static int __init stm_core_init(void) 11027bd1d409SAlexander Shishkin { 11037bd1d409SAlexander Shishkin int err; 11047bd1d409SAlexander Shishkin 11057bd1d409SAlexander Shishkin err = class_register(&stm_class); 11067bd1d409SAlexander Shishkin if (err) 11077bd1d409SAlexander Shishkin return err; 11087bd1d409SAlexander Shishkin 11097bd1d409SAlexander Shishkin err = class_register(&stm_source_class); 11107bd1d409SAlexander Shishkin if (err) 11117bd1d409SAlexander Shishkin goto err_stm; 11127bd1d409SAlexander Shishkin 11137bd1d409SAlexander Shishkin err = stp_configfs_init(); 11147bd1d409SAlexander Shishkin if (err) 11157bd1d409SAlexander Shishkin goto err_src; 11167bd1d409SAlexander Shishkin 11177bd1d409SAlexander Shishkin init_srcu_struct(&stm_source_srcu); 11187bd1d409SAlexander Shishkin 11197bd1d409SAlexander Shishkin stm_core_up++; 11207bd1d409SAlexander Shishkin 11217bd1d409SAlexander Shishkin return 0; 11227bd1d409SAlexander Shishkin 11237bd1d409SAlexander Shishkin err_src: 11247bd1d409SAlexander Shishkin class_unregister(&stm_source_class); 11257bd1d409SAlexander Shishkin err_stm: 11267bd1d409SAlexander Shishkin class_unregister(&stm_class); 11277bd1d409SAlexander Shishkin 11287bd1d409SAlexander Shishkin return err; 11297bd1d409SAlexander Shishkin } 11307bd1d409SAlexander Shishkin 11317bd1d409SAlexander Shishkin module_init(stm_core_init); 11327bd1d409SAlexander Shishkin 11337bd1d409SAlexander Shishkin static void __exit stm_core_exit(void) 11347bd1d409SAlexander Shishkin { 11357bd1d409SAlexander Shishkin cleanup_srcu_struct(&stm_source_srcu); 11367bd1d409SAlexander Shishkin class_unregister(&stm_source_class); 11377bd1d409SAlexander Shishkin class_unregister(&stm_class); 11387bd1d409SAlexander Shishkin stp_configfs_exit(); 11397bd1d409SAlexander Shishkin } 11407bd1d409SAlexander Shishkin 11417bd1d409SAlexander Shishkin module_exit(stm_core_exit); 11427bd1d409SAlexander Shishkin 11437bd1d409SAlexander Shishkin MODULE_LICENSE("GPL v2"); 11447bd1d409SAlexander Shishkin MODULE_DESCRIPTION("System Trace Module device class"); 11457bd1d409SAlexander Shishkin MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); 1146