// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2005-2007 Kristian Hoegsberg <krh@bitplanet.net> */ #include <linux/bug.h>#include <linux/completion.h>#include <linux/crc-itu-t.h>#include <linux/device.h>#include <linux/errno.h>#include <linux/firewire.h>#include <linux/firewire-constants.h>#include <linux/jiffies.h>#include <linux/kernel.h>#include <linux/kref.h>#include <linux/list.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/minmax.h>#include <linux/spinlock.h>#include <linux/workqueue.h> #include <linux/atomic.h>#include <asm/byteorder.h> #include "core.h"#include <trace/events/firewire.h> #define define_fw_printk_level(func, kern_level) \void func(const struct fw_card *card, const char *fmt, ...) \{ \ struct va_format vaf; \ va_list args; \ \ va_start(args, fmt); \ vaf.fmt = fmt; \ vaf.va = &args; \ printk(kern_level KBUILD_MODNAME " %s: %pV", \ dev_name(card->device), &vaf); \ va_end(args); \}define_fw_printk_level(fw_err, KERN_ERR);define_fw_printk_level(fw_notice, KERN_NOTICE); int fw_compute_block_crc(__be32 *block){ int length; u16 crc; length = (be32_to_cpu(block[0]) >> 16) & 0xff; crc = crc_itu_t(0, (u8 *)&block[1], length * 4); *block |= cpu_to_be32(crc); return length;} static DEFINE_MUTEX(card_mutex);static LIST_HEAD(card_list); static LIST_HEAD(descriptor_list);static int descriptor_count; static __be32 tmp_config_rom[256];/* ROM header, bus info block, root dir header, capabilities = 7 quadlets */static size_t config_rom_length = 1 + 4 + 1 + 1; #define BIB_CRC(v) ((v) << 0)#define BIB_CRC_LENGTH(v) ((v) << 16)#define BIB_INFO_LENGTH(v) ((v) << 24)#define BIB_BUS_NAME 0x31333934 /* "1394" */#define BIB_LINK_SPEED(v) ((v) << 0)#define BIB_GENERATION(v) ((v) << 4)#define BIB_MAX_ROM(v) ((v) << 8)#define BIB_MAX_RECEIVE(v) ((v) << 12)#define BIB_CYC_CLK_ACC(v) ((v) << 16)#define BIB_PMC ((1) << 27)#define BIB_BMC ((1) << 28)#define BIB_ISC ((1) << 29)#define BIB_CMC ((1) << 30)#define BIB_IRMC ((1) << 31)#define NODE_CAPABILITIES 0x0c0083c0 /* per IEEE 1394 clause 8.3.2.6.5.2 */ /* * IEEE-1394 specifies a default SPLIT_TIMEOUT value of 800 cycles (100 ms), * but we have to make it longer because there are many devices whose firmware * is just too slow for that. */#define DEFAULT_SPLIT_TIMEOUT (2 * 8000) static void generate_config_rom(struct fw_card *card, __be32 *config_rom){ struct fw_descriptor *desc; int i, j, k, length; /* * Initialize contents of config rom buffer. On the OHCI * controller, block reads to the config rom accesses the host * memory, but quadlet read access the hardware bus info block * registers. That's just crack, but it means we should make * sure the contents of bus info block in host memory matches * the version stored in the OHCI registers. */ config_rom[0] = cpu_to_be32( BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0)); config_rom[1] = cpu_to_be32(BIB_BUS_NAME); config_rom[2] = cpu_to_be32( BIB_LINK_SPEED(card->link_speed) | BIB_GENERATION(card->config_rom_generation++ % 14 + 2) | BIB_MAX_ROM(2) | BIB_MAX_RECEIVE(card->max_receive) | BIB_BMC | BIB_ISC | BIB_CMC | BIB_IRMC); config_rom[3] = cpu_to_be32(card->guid >> 32); config_rom[4] = cpu_to_be32(card->guid); /* Generate root directory. */ config_rom[6] = cpu_to_be32(NODE_CAPABILITIES); i = 7; j = 7 + descriptor_count; /* Generate root directory entries for descriptors. */ list_for_each_entry (desc, &descriptor_list, link) { if (desc->immediate > 0) config_rom[i++] = cpu_to_be32(desc->immediate); config_rom[i] = cpu_to_be32(desc->key | (j - i)); i++; j += desc->length; } /* Update root directory length. */ config_rom[5] = cpu_to_be32((i - 5 - 1) << 16); /* End of root directory, now copy in descriptors. */ list_for_each_entry (desc, &descriptor_list, link) { for (k = 0; k < desc->length; k++) config_rom[i + k] = cpu_to_be32(desc->data[k]); i += desc->length; } /* Calculate CRCs for all blocks in the config rom. This * assumes that CRC length and info length are identical for * the bus info block, which is always the case for this * implementation. */ for (i = 0; i < j; i += length + 1) length = fw_compute_block_crc(config_rom + i); WARN_ON(j != config_rom_length);} static void update_config_roms(void){ struct fw_card *card; list_for_each_entry (card, &card_list, link) { generate_config_rom(card, tmp_config_rom); card->driver->set_config_rom(card, tmp_config_rom, config_rom_length); }} static size_t required_space(struct fw_descriptor *desc){ /* descriptor + entry into root dir + optional immediate entry */ return desc->length + 1 + (desc->immediate > 0 ? 1 : 0);} int fw_core_add_descriptor(struct fw_descriptor *desc){ size_t i; /* Reject empty descriptors or those exceeding max Config ROM size (256 quadlets) */ if (!in_range(desc->length, 1, 256)) return -EINVAL; i = 0; /* * Validate internal block structures within the descriptor. Each sub-block * encodes its length in the top 16 bits of its header quadlet. */ while (i < desc->length) { u16 block_len = desc->data[i] >> 16; /* * Guard against corrupted descriptors where an individual block length * claims to extend past the allocated end of desc->data, avoiding * out-of-bounds reads. */ if (block_len >= desc->length - i) return -EINVAL; i += block_len + 1; } /* The sum of sub-block lengths must match total descriptor length */ if (i != desc->length) return -EINVAL; guard(mutex)(&card_mutex); if (config_rom_length + required_space(desc) > 256) return -EBUSY; list_add_tail(&desc->link, &descriptor_list); config_rom_length += required_space(desc); descriptor_count++; if (desc->immediate > 0) descriptor_count++; update_config_roms(); return 0;}EXPORT_SYMBOL(fw_core_add_descriptor); void fw_core_remove_descriptor(struct fw_descriptor *desc){ guard(mutex)(&card_mutex); list_del(&desc->link); config_rom_length -= required_space(desc); descriptor_count--; if (desc->immediate > 0) descriptor_count--; update_config_roms();}EXPORT_SYMBOL(fw_core_remove_descriptor); static int reset_bus(struct fw_card *card, bool short_reset){ int reg = short_reset ? 5 : 1; int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET; trace_bus_reset_initiate(card->index, card->generation, short_reset); return card->driver->update_phy_reg(card, reg, 0, bit);} void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset){ trace_bus_reset_schedule(card->index, card->generation, short_reset); /* We don't try hard to sort out requests of long vs. short resets. */ card->br_short = short_reset; /* Use an arbitrary short delay to combine multiple reset requests. */ fw_card_get(card); if (!queue_delayed_work(fw_workqueue, &card->br_work, delayed ? msecs_to_jiffies(10) : 0)) fw_card_put(card);}EXPORT_SYMBOL(fw_schedule_bus_reset); static void br_work(struct work_struct *work){ struct fw_card *card = from_work(card, work, br_work.work); /* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */ if (card->reset_jiffies != 0 && time_is_after_jiffies64(card->reset_jiffies + secs_to_jiffies(2))) { trace_bus_reset_postpone(card->index, card->generation, card->br_short); if (!queue_delayed_work(fw_workqueue, &card->br_work, secs_to_jiffies(2))) fw_card_put(card); return; } fw_send_phy_config(card, FW_PHY_CONFIG_NO_NODE_ID, card->generation, FW_PHY_CONFIG_CURRENT_GAP_COUNT); reset_bus(card, card->br_short); fw_card_put(card);} static void allocate_broadcast_channel(struct fw_card *card, int generation){ int channel, bandwidth = 0; if (!card->broadcast_channel_allocated) { fw_iso_resource_manage(card, generation, 1ULL << 31, &channel, &bandwidth, true); if (channel != 31) { fw_notice(card, "failed to allocate broadcast channel\n"); return; } card->broadcast_channel_allocated = true; } device_for_each_child(card->device, (void *)(long)generation, fw_device_set_broadcast_channel);} void fw_schedule_bm_work(struct fw_card *card, unsigned long delay){ fw_card_get(card); if (!schedule_delayed_work(&card->bm_work, delay)) fw_card_put(card);} enum bm_contention_outcome { // The bus management contention window is not expired. BM_CONTENTION_OUTCOME_WITHIN_WINDOW = 0, // The IRM node has link off. BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF, // The IRM node complies IEEE 1394:1994 only. BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY, // Another bus reset, BM work has been rescheduled. BM_CONTENTION_OUTCOME_AT_NEW_GENERATION, // We have been unable to send the lock request to IRM node due to some local problem. BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION, // The lock request failed, maybe the IRM isn't really IRM capable after all. BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM, // Somebody else is BM. BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM, // The local node succeeds after contending for bus manager. BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM,}; static enum bm_contention_outcome contend_for_bm(struct fw_card *card)__must_hold(&card->lock){ int generation = card->generation; int local_id = card->local_node->node_id; __be32 data[2] = { cpu_to_be32(BUS_MANAGER_ID_NOT_REGISTERED), cpu_to_be32(local_id), }; bool grace = time_is_before_jiffies64(card->reset_jiffies + msecs_to_jiffies(125)); struct fw_node *irm_node; struct fw_device *irm_device; int irm_node_id, irm_device_quirks = 0; int rcode; lockdep_assert_held(&card->lock); if (!grace) { if (!is_next_generation(generation, card->bm_generation) || card->bm_abdicate) return BM_CONTENTION_OUTCOME_WITHIN_WINDOW; } irm_node = card->irm_node; if (!irm_node->link_on) { fw_notice(card, "IRM has link off, making local node (%02x) root\n", local_id); return BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF; } // NOTE: It is likely that the quirk detection for IRM device has not done yet. irm_device = fw_node_get_device(irm_node); if (irm_device) irm_device_quirks = READ_ONCE(irm_device->quirks); if ((irm_device_quirks & FW_DEVICE_QUIRK_IRM_IS_1394_1995_ONLY) && !(irm_device_quirks & FW_DEVICE_QUIRK_IRM_IGNORES_BUS_MANAGER)) { fw_notice(card, "IRM is not 1394a compliant, making local node (%02x) root\n", local_id); return BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY; } irm_node_id = irm_node->node_id; spin_unlock_irq(&card->lock); rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, irm_node_id, generation, SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID, data, sizeof(data)); spin_lock_irq(&card->lock); switch (rcode) { case RCODE_GENERATION: return BM_CONTENTION_OUTCOME_AT_NEW_GENERATION; case RCODE_SEND_ERROR: return BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION; case RCODE_COMPLETE: { int bm_id = be32_to_cpu(data[0]); // Used by cdev layer for "struct fw_cdev_event_bus_reset". if (bm_id != BUS_MANAGER_ID_NOT_REGISTERED) card->bm_node_id = 0xffc0 & bm_id; else card->bm_node_id = local_id; if (bm_id != BUS_MANAGER_ID_NOT_REGISTERED) return BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM; else return BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM; } default: if (!(irm_device_quirks & FW_DEVICE_QUIRK_IRM_IGNORES_BUS_MANAGER)) { fw_notice(card, "BM lock failed (%s), making local node (%02x) root\n", fw_rcode_string(rcode), local_id); return BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY; } else { return BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM; } }} DEFINE_FREE(node_unref, struct fw_node *, if (_T) fw_node_put(_T))DEFINE_FREE(card_unref, struct fw_card *, if (_T) fw_card_put(_T)) static void bm_work(struct work_struct *work){ static const char gap_count_table[] = { 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40 }; struct fw_card *card __free(card_unref) = from_work(card, work, bm_work.work); struct fw_node *root_node __free(node_unref) = NULL; int root_id, new_root_id, irm_id, local_id; int expected_gap_count, generation; bool stand_for_root = false; spin_lock_irq(&card->lock); if (card->local_node == NULL) { spin_unlock_irq(&card->lock); return; } generation = card->generation; root_node = fw_node_get(card->root_node); root_id = root_node->node_id; irm_id = card->irm_node->node_id; local_id = card->local_node->node_id; if (card->bm_generation != generation) { enum bm_contention_outcome result = contend_for_bm(card); switch (result) { case BM_CONTENTION_OUTCOME_WITHIN_WINDOW: spin_unlock_irq(&card->lock); fw_schedule_bm_work(card, msecs_to_jiffies(125)); return; case BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF: stand_for_root = true; break; case BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY: stand_for_root = true; break; case BM_CONTENTION_OUTCOME_AT_NEW_GENERATION: // BM work has been rescheduled. spin_unlock_irq(&card->lock); return; case BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION: // Let's try again later and hope that the local problem has gone away by // then. spin_unlock_irq(&card->lock); fw_schedule_bm_work(card, msecs_to_jiffies(125)); return; case BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM: // Let's do a bus reset and pick the local node as root, and thus, IRM. stand_for_root = true; break; case BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM: if (local_id == irm_id) { // Only acts as IRM. spin_unlock_irq(&card->lock); allocate_broadcast_channel(card, generation); spin_lock_irq(&card->lock); } fallthrough; case BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM: default: card->bm_generation = generation; break; } } // We're bus manager for this generation, so next step is to make sure we have an active // cycle master and do gap count optimization. if (!stand_for_root) { if (card->gap_count == GAP_COUNT_MISMATCHED) { // If self IDs have inconsistent gap counts, do a // bus reset ASAP. The config rom read might never // complete, so don't wait for it. However, still // send a PHY configuration packet prior to the // bus reset. The PHY configuration packet might // fail, but 1394-2008 8.4.5.2 explicitly permits // it in this case, so it should be safe to try. stand_for_root = true; // We must always send a bus reset if the gap count // is inconsistent, so bypass the 5-reset limit. card->bm_retries = 0; } else { // Now investigate root node. struct fw_device *root_device = fw_node_get_device(root_node); if (root_device == NULL) { // Either link_on is false, or we failed to read the // config rom. In either case, pick another root. stand_for_root = true; } else { bool root_device_is_running = atomic_read(&root_device->state) == FW_DEVICE_RUNNING; if (!root_device_is_running) { // If we haven't probed this device yet, bail out now // and let's try again once that's done. spin_unlock_irq(&card->lock); return; } else if (!root_device->cmc) {Lines 1–500 of 853. Load more
// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2005-2007 Kristian Hoegsberg <krh@bitplanet.net> */ #include <linux/bug.h> #include <linux/completion.h> #include <linux/crc-itu-t.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/firewire.h> #include <linux/firewire-constants.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/minmax.h> #include <linux/spinlock.h> #include <linux/workqueue.h> #include <linux/atomic.h> #include <asm/byteorder.h> #include "core.h" #include <trace/events/firewire.h> #define define_fw_printk_level(func, kern_level) \ void func(const struct fw_card *card, const char *fmt, ...) \ { \ struct va_format vaf; \ va_list args; \ \ va_start(args, fmt); \ vaf.fmt = fmt; \ vaf.va = &args; \ printk(kern_level KBUILD_MODNAME " %s: %pV", \ dev_name(card->device), &vaf); \ va_end(args); \ } define_fw_printk_level(fw_err, KERN_ERR); define_fw_printk_level(fw_notice, KERN_NOTICE); int fw_compute_block_crc(__be32 *block) { int length; u16 crc; length = (be32_to_cpu(block[0]) >> 16) & 0xff; crc = crc_itu_t(0, (u8 *)&block[1], length * 4); *block |= cpu_to_be32(crc); return length; } static DEFINE_MUTEX(card_mutex); static LIST_HEAD(card_list); static LIST_HEAD(descriptor_list); static int descriptor_count; static __be32 tmp_config_rom[256]; /* ROM header, bus info block, root dir header, capabilities = 7 quadlets */ static size_t config_rom_length = 1 + 4 + 1 + 1; #define BIB_CRC(v) ((v) << 0) #define BIB_CRC_LENGTH(v) ((v) << 16) #define BIB_INFO_LENGTH(v) ((v) << 24) #define BIB_BUS_NAME 0x31333934 /* "1394" */ #define BIB_LINK_SPEED(v) ((v) << 0) #define BIB_GENERATION(v) ((v) << 4) #define BIB_MAX_ROM(v) ((v) << 8) #define BIB_MAX_RECEIVE(v) ((v) << 12) #define BIB_CYC_CLK_ACC(v) ((v) << 16) #define BIB_PMC ((1) << 27) #define BIB_BMC ((1) << 28) #define BIB_ISC ((1) << 29) #define BIB_CMC ((1) << 30) #define BIB_IRMC ((1) << 31) #define NODE_CAPABILITIES 0x0c0083c0 /* per IEEE 1394 clause 8.3.2.6.5.2 */ /* * IEEE-1394 specifies a default SPLIT_TIMEOUT value of 800 cycles (100 ms), * but we have to make it longer because there are many devices whose firmware * is just too slow for that. */ #define DEFAULT_SPLIT_TIMEOUT (2 * 8000) static void generate_config_rom(struct fw_card *card, __be32 *config_rom) { struct fw_descriptor *desc; int i, j, k, length; /* * Initialize contents of config rom buffer. On the OHCI * controller, block reads to the config rom accesses the host * memory, but quadlet read access the hardware bus info block * registers. That's just crack, but it means we should make * sure the contents of bus info block in host memory matches * the version stored in the OHCI registers. */ config_rom[0] = cpu_to_be32( BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0)); config_rom[1] = cpu_to_be32(BIB_BUS_NAME); config_rom[2] = cpu_to_be32( BIB_LINK_SPEED(card->link_speed) | BIB_GENERATION(card->config_rom_generation++ % 14 + 2) | BIB_MAX_ROM(2) | BIB_MAX_RECEIVE(card->max_receive) | BIB_BMC | BIB_ISC | BIB_CMC | BIB_IRMC); config_rom[3] = cpu_to_be32(card->guid >> 32); config_rom[4] = cpu_to_be32(card->guid); /* Generate root directory. */ config_rom[6] = cpu_to_be32(NODE_CAPABILITIES); i = 7; j = 7 + descriptor_count; /* Generate root directory entries for descriptors. */ list_for_each_entry (desc, &descriptor_list, link) { if (desc->immediate > 0) config_rom[i++] = cpu_to_be32(desc->immediate); config_rom[i] = cpu_to_be32(desc->key | (j - i)); i++; j += desc->length; } /* Update root directory length. */ config_rom[5] = cpu_to_be32((i - 5 - 1) << 16); /* End of root directory, now copy in descriptors. */ list_for_each_entry (desc, &descriptor_list, link) { for (k = 0; k < desc->length; k++) config_rom[i + k] = cpu_to_be32(desc->data[k]); i += desc->length; } /* Calculate CRCs for all blocks in the config rom. This * assumes that CRC length and info length are identical for * the bus info block, which is always the case for this * implementation. */ for (i = 0; i < j; i += length + 1) length = fw_compute_block_crc(config_rom + i); WARN_ON(j != config_rom_length); } static void update_config_roms(void) { struct fw_card *card; list_for_each_entry (card, &card_list, link) { generate_config_rom(card, tmp_config_rom); card->driver->set_config_rom(card, tmp_config_rom, config_rom_length); } } static size_t required_space(struct fw_descriptor *desc) { /* descriptor + entry into root dir + optional immediate entry */ return desc->length + 1 + (desc->immediate > 0 ? 1 : 0); } int fw_core_add_descriptor(struct fw_descriptor *desc) { size_t i; /* Reject empty descriptors or those exceeding max Config ROM size (256 quadlets) */ if (!in_range(desc->length, 1, 256)) return -EINVAL; i = 0; /* * Validate internal block structures within the descriptor. Each sub-block * encodes its length in the top 16 bits of its header quadlet. */ while (i < desc->length) { u16 block_len = desc->data[i] >> 16; /* * Guard against corrupted descriptors where an individual block length * claims to extend past the allocated end of desc->data, avoiding * out-of-bounds reads. */ if (block_len >= desc->length - i) return -EINVAL; i += block_len + 1; } /* The sum of sub-block lengths must match total descriptor length */ if (i != desc->length) return -EINVAL; guard(mutex)(&card_mutex); if (config_rom_length + required_space(desc) > 256) return -EBUSY; list_add_tail(&desc->link, &descriptor_list); config_rom_length += required_space(desc); descriptor_count++; if (desc->immediate > 0) descriptor_count++; update_config_roms(); return 0; } EXPORT_SYMBOL(fw_core_add_descriptor); void fw_core_remove_descriptor(struct fw_descriptor *desc) { guard(mutex)(&card_mutex); list_del(&desc->link); config_rom_length -= required_space(desc); descriptor_count--; if (desc->immediate > 0) descriptor_count--; update_config_roms(); } EXPORT_SYMBOL(fw_core_remove_descriptor); static int reset_bus(struct fw_card *card, bool short_reset) { int reg = short_reset ? 5 : 1; int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET; trace_bus_reset_initiate(card->index, card->generation, short_reset); return card->driver->update_phy_reg(card, reg, 0, bit); } void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset) { trace_bus_reset_schedule(card->index, card->generation, short_reset); /* We don't try hard to sort out requests of long vs. short resets. */ card->br_short = short_reset; /* Use an arbitrary short delay to combine multiple reset requests. */ fw_card_get(card); if (!queue_delayed_work(fw_workqueue, &card->br_work, delayed ? msecs_to_jiffies(10) : 0)) fw_card_put(card); } EXPORT_SYMBOL(fw_schedule_bus_reset); static void br_work(struct work_struct *work) { struct fw_card *card = from_work(card, work, br_work.work); /* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */ if (card->reset_jiffies != 0 && time_is_after_jiffies64(card->reset_jiffies + secs_to_jiffies(2))) { trace_bus_reset_postpone(card->index, card->generation, card->br_short); if (!queue_delayed_work(fw_workqueue, &card->br_work, secs_to_jiffies(2))) fw_card_put(card); return; } fw_send_phy_config(card, FW_PHY_CONFIG_NO_NODE_ID, card->generation, FW_PHY_CONFIG_CURRENT_GAP_COUNT); reset_bus(card, card->br_short); fw_card_put(card); } static void allocate_broadcast_channel(struct fw_card *card, int generation) { int channel, bandwidth = 0; if (!card->broadcast_channel_allocated) { fw_iso_resource_manage(card, generation, 1ULL << 31, &channel, &bandwidth, true); if (channel != 31) { fw_notice(card, "failed to allocate broadcast channel\n"); return; } card->broadcast_channel_allocated = true; } device_for_each_child(card->device, (void *)(long)generation, fw_device_set_broadcast_channel); } void fw_schedule_bm_work(struct fw_card *card, unsigned long delay) { fw_card_get(card); if (!schedule_delayed_work(&card->bm_work, delay)) fw_card_put(card); } enum bm_contention_outcome { // The bus management contention window is not expired. BM_CONTENTION_OUTCOME_WITHIN_WINDOW = 0, // The IRM node has link off. BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF, // The IRM node complies IEEE 1394:1994 only. BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY, // Another bus reset, BM work has been rescheduled. BM_CONTENTION_OUTCOME_AT_NEW_GENERATION, // We have been unable to send the lock request to IRM node due to some local problem. BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION, // The lock request failed, maybe the IRM isn't really IRM capable after all. BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM, // Somebody else is BM. BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM, // The local node succeeds after contending for bus manager. BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM, }; static enum bm_contention_outcome contend_for_bm(struct fw_card *card) __must_hold(&card->lock) { int generation = card->generation; int local_id = card->local_node->node_id; __be32 data[2] = { cpu_to_be32(BUS_MANAGER_ID_NOT_REGISTERED), cpu_to_be32(local_id), }; bool grace = time_is_before_jiffies64(card->reset_jiffies + msecs_to_jiffies(125)); struct fw_node *irm_node; struct fw_device *irm_device; int irm_node_id, irm_device_quirks = 0; int rcode; lockdep_assert_held(&card->lock); if (!grace) { if (!is_next_generation(generation, card->bm_generation) || card->bm_abdicate) return BM_CONTENTION_OUTCOME_WITHIN_WINDOW; } irm_node = card->irm_node; if (!irm_node->link_on) { fw_notice(card, "IRM has link off, making local node (%02x) root\n", local_id); return BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF; } // NOTE: It is likely that the quirk detection for IRM device has not done yet. irm_device = fw_node_get_device(irm_node); if (irm_device) irm_device_quirks = READ_ONCE(irm_device->quirks); if ((irm_device_quirks & FW_DEVICE_QUIRK_IRM_IS_1394_1995_ONLY) && !(irm_device_quirks & FW_DEVICE_QUIRK_IRM_IGNORES_BUS_MANAGER)) { fw_notice(card, "IRM is not 1394a compliant, making local node (%02x) root\n", local_id); return BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY; } irm_node_id = irm_node->node_id; spin_unlock_irq(&card->lock); rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, irm_node_id, generation, SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID, data, sizeof(data)); spin_lock_irq(&card->lock); switch (rcode) { case RCODE_GENERATION: return BM_CONTENTION_OUTCOME_AT_NEW_GENERATION; case RCODE_SEND_ERROR: return BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION; case RCODE_COMPLETE: { int bm_id = be32_to_cpu(data[0]); // Used by cdev layer for "struct fw_cdev_event_bus_reset". if (bm_id != BUS_MANAGER_ID_NOT_REGISTERED) card->bm_node_id = 0xffc0 & bm_id; else card->bm_node_id = local_id; if (bm_id != BUS_MANAGER_ID_NOT_REGISTERED) return BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM; else return BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM; } default: if (!(irm_device_quirks & FW_DEVICE_QUIRK_IRM_IGNORES_BUS_MANAGER)) { fw_notice(card, "BM lock failed (%s), making local node (%02x) root\n", fw_rcode_string(rcode), local_id); return BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY; } else { return BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM; } } } DEFINE_FREE(node_unref, struct fw_node *, if (_T) fw_node_put(_T)) DEFINE_FREE(card_unref, struct fw_card *, if (_T) fw_card_put(_T)) static void bm_work(struct work_struct *work) { static const char gap_count_table[] = { 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40 }; struct fw_card *card __free(card_unref) = from_work(card, work, bm_work.work); struct fw_node *root_node __free(node_unref) = NULL; int root_id, new_root_id, irm_id, local_id; int expected_gap_count, generation; bool stand_for_root = false; spin_lock_irq(&card->lock); if (card->local_node == NULL) { spin_unlock_irq(&card->lock); return; } generation = card->generation; root_node = fw_node_get(card->root_node); root_id = root_node->node_id; irm_id = card->irm_node->node_id; local_id = card->local_node->node_id; if (card->bm_generation != generation) { enum bm_contention_outcome result = contend_for_bm(card); switch (result) { case BM_CONTENTION_OUTCOME_WITHIN_WINDOW: spin_unlock_irq(&card->lock); fw_schedule_bm_work(card, msecs_to_jiffies(125)); return; case BM_CONTENTION_OUTCOME_IRM_HAS_LINK_OFF: stand_for_root = true; break; case BM_CONTENTION_OUTCOME_IRM_COMPLIES_1394_1995_ONLY: stand_for_root = true; break; case BM_CONTENTION_OUTCOME_AT_NEW_GENERATION: // BM work has been rescheduled. spin_unlock_irq(&card->lock); return; case BM_CONTENTION_OUTCOME_LOCAL_PROBLEM_AT_TRANSACTION: // Let's try again later and hope that the local problem has gone away by // then. spin_unlock_irq(&card->lock); fw_schedule_bm_work(card, msecs_to_jiffies(125)); return; case BM_CONTENTION_OUTCOME_IRM_IS_NOT_CAPABLE_FOR_IRM: // Let's do a bus reset and pick the local node as root, and thus, IRM. stand_for_root = true; break; case BM_CONTENTION_OUTCOME_IRM_HOLDS_ANOTHER_NODE_AS_BM: if (local_id == irm_id) { // Only acts as IRM. spin_unlock_irq(&card->lock); allocate_broadcast_channel(card, generation); spin_lock_irq(&card->lock); } fallthrough; case BM_CONTENTION_OUTCOME_IRM_HOLDS_LOCAL_NODE_AS_BM: default: card->bm_generation = generation; break; } } // We're bus manager for this generation, so next step is to make sure we have an active // cycle master and do gap count optimization. if (!stand_for_root) { if (card->gap_count == GAP_COUNT_MISMATCHED) { // If self IDs have inconsistent gap counts, do a // bus reset ASAP. The config rom read might never // complete, so don't wait for it. However, still // send a PHY configuration packet prior to the // bus reset. The PHY configuration packet might // fail, but 1394-2008 8.4.5.2 explicitly permits // it in this case, so it should be safe to try. stand_for_root = true; // We must always send a bus reset if the gap count // is inconsistent, so bypass the 5-reset limit. card->bm_retries = 0; } else { // Now investigate root node. struct fw_device *root_device = fw_node_get_device(root_node); if (root_device == NULL) { // Either link_on is false, or we failed to read the // config rom. In either case, pick another root. stand_for_root = true; } else { bool root_device_is_running = atomic_read(&root_device->state) == FW_DEVICE_RUNNING; if (!root_device_is_running) { // If we haven't probed this device yet, bail out now // and let's try again once that's done. spin_unlock_irq(&card->lock); return; } else if (!root_device->cmc) {