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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Core IEEE1394 transaction logic
  *
  * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
  */
 
 #include <linux/bug.h>
 #include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/firewire.h>
 #include <linux/firewire-constants.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/idr.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/rculist.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
 #include <asm/byteorder.h>
 
 #include "core.h"
 
 #define HEADER_PRI(pri)         ((pri) << 0)
 #define HEADER_TCODE(tcode)     ((tcode) << 4)
 #define HEADER_RETRY(retry)     ((retry) << 8)
 #define HEADER_TLABEL(tlabel)       ((tlabel) << 10)
 #define HEADER_DESTINATION(destination) ((destination) << 16)
 #define HEADER_SOURCE(source)       ((source) << 16)
 #define HEADER_RCODE(rcode)     ((rcode) << 12)
 #define HEADER_OFFSET_HIGH(offset_high) ((offset_high) << 0)
 #define HEADER_DATA_LENGTH(length)  ((length) << 16)
 #define HEADER_EXTENDED_TCODE(tcode)    ((tcode) << 0)
 
 #define HEADER_GET_TCODE(q)     (((q) >> 4) & 0x0f)
 #define HEADER_GET_TLABEL(q)        (((q) >> 10) & 0x3f)
 #define HEADER_GET_RCODE(q)     (((q) >> 12) & 0x0f)
 #define HEADER_GET_DESTINATION(q)   (((q) >> 16) & 0xffff)
 #define HEADER_GET_SOURCE(q)        (((q) >> 16) & 0xffff)
 #define HEADER_GET_OFFSET_HIGH(q)   (((q) >> 0) & 0xffff)
 #define HEADER_GET_DATA_LENGTH(q)   (((q) >> 16) & 0xffff)
 #define HEADER_GET_EXTENDED_TCODE(q)    (((q) >> 0) & 0xffff)
 
 #define HEADER_DESTINATION_IS_BROADCAST(q) \
     (((q) & HEADER_DESTINATION(0x3f)) == HEADER_DESTINATION(0x3f))
 
 #define PHY_PACKET_CONFIG   0x0
 #define PHY_PACKET_LINK_ON  0x1
 #define PHY_PACKET_SELF_ID  0x2
 
 #define PHY_CONFIG_GAP_COUNT(gap_count) (((gap_count) << 16) | (1 << 22))
 #define PHY_CONFIG_ROOT_ID(node_id) ((((node_id) & 0x3f) << 24) | (1 << 23))
 #define PHY_IDENTIFIER(id)      ((id) << 30)
 
 /* returns 0 if the split timeout handler is already running */
 static int try_cancel_split_timeout(struct fw_transaction *t)
 {
     if (t->is_split_transaction)
         return del_timer(&t->split_timeout_timer);
     else
         return 1;
 }
 
 static int close_transaction(struct fw_transaction *transaction,
                  struct fw_card *card, int rcode)
 {
     struct fw_transaction *t = NULL, *iter;
     unsigned long flags;
 
     spin_lock_irqsave(&card->lock, flags);
     list_for_each_entry(iter, &card->transaction_list, link) {
         if (iter == transaction) {
             if (!try_cancel_split_timeout(iter)) {
                 spin_unlock_irqrestore(&card->lock, flags);
                 goto timed_out;
             }
             list_del_init(&iter->link);
             card->tlabel_mask &= ~(1ULL << iter->tlabel);
             t = iter;
             break;
         }
     }
     spin_unlock_irqrestore(&card->lock, flags);
 
     if (t) {
         t->callback(card, rcode, NULL, 0, t->callback_data);
         return 0;
     }
 
  timed_out:
     return -ENOENT;
 }
 
 /*
  * Only valid for transactions that are potentially pending (ie have
  * been sent).
  */
 int fw_cancel_transaction(struct fw_card *card,
               struct fw_transaction *transaction)
 {
     /*
      * Cancel the packet transmission if it's still queued.  That
      * will call the packet transmission callback which cancels
      * the transaction.
      */
 
     if (card->driver->cancel_packet(card, &transaction->packet) == 0)
         return 0;
 
     /*
      * If the request packet has already been sent, we need to see
      * if the transaction is still pending and remove it in that case.
      */
 
     return close_transaction(transaction, card, RCODE_CANCELLED);
 }
 EXPORT_SYMBOL(fw_cancel_transaction);
 
 static void split_transaction_timeout_callback(struct timer_list *timer)
 {
     struct fw_transaction *t = from_timer(t, timer, split_timeout_timer);
     struct fw_card *card = t->card;
     unsigned long flags;
 
     spin_lock_irqsave(&card->lock, flags);
     if (list_empty(&t->link)) {
         spin_unlock_irqrestore(&card->lock, flags);
         return;
     }
     list_del(&t->link);
     card->tlabel_mask &= ~(1ULL << t->tlabel);
     spin_unlock_irqrestore(&card->lock, flags);
 
     t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
 }
 
 static void start_split_transaction_timeout(struct fw_transaction *t,
                         struct fw_card *card)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&card->lock, flags);
 
     if (list_empty(&t->link) || WARN_ON(t->is_split_transaction)) {
         spin_unlock_irqrestore(&card->lock, flags);
         return;
     }
 
     t->is_split_transaction = true;
     mod_timer(&t->split_timeout_timer,
           jiffies + card->split_timeout_jiffies);
 
     spin_unlock_irqrestore(&card->lock, flags);
 }
 
 static void transmit_complete_callback(struct fw_packet *packet,
                        struct fw_card *card, int status)
 {
     struct fw_transaction *t =
         container_of(packet, struct fw_transaction, packet);
 
     switch (status) {
     case ACK_COMPLETE:
         close_transaction(t, card, RCODE_COMPLETE);
         break;
     case ACK_PENDING:
         start_split_transaction_timeout(t, card);
         break;
     case ACK_BUSY_X:
     case ACK_BUSY_A:
     case ACK_BUSY_B:
         close_transaction(t, card, RCODE_BUSY);
         break;
     case ACK_DATA_ERROR:
         close_transaction(t, card, RCODE_DATA_ERROR);
         break;
     case ACK_TYPE_ERROR:
         close_transaction(t, card, RCODE_TYPE_ERROR);
         break;
     default:
         /*
          * In this case the ack is really a juju specific
          * rcode, so just forward that to the callback.
          */
         close_transaction(t, card, status);
         break;
     }
 }
 
 static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
         int destination_id, int source_id, int generation, int speed,
         unsigned long long offset, void *payload, size_t length)
 {
     int ext_tcode;
 
     if (tcode == TCODE_STREAM_DATA) {
         packet->header[0] =
             HEADER_DATA_LENGTH(length) |
             destination_id |
             HEADER_TCODE(TCODE_STREAM_DATA);
         packet->header_length = 4;
         packet->payload = payload;
         packet->payload_length = length;
 
         goto common;
     }
 
     if (tcode > 0x10) {
         ext_tcode = tcode & ~0x10;
         tcode = TCODE_LOCK_REQUEST;
     } else
         ext_tcode = 0;
 
     packet->header[0] =
         HEADER_RETRY(RETRY_X) |
         HEADER_TLABEL(tlabel) |
         HEADER_TCODE(tcode) |
         HEADER_DESTINATION(destination_id);
     packet->header[1] =
         HEADER_OFFSET_HIGH(offset >> 32) | HEADER_SOURCE(source_id);
     packet->header[2] =
         offset;
 
     switch (tcode) {
     case TCODE_WRITE_QUADLET_REQUEST:
         packet->header[3] = *(u32 *)payload;
         packet->header_length = 16;
         packet->payload_length = 0;
         break;
 
     case TCODE_LOCK_REQUEST:
     case TCODE_WRITE_BLOCK_REQUEST:
         packet->header[3] =
             HEADER_DATA_LENGTH(length) |
             HEADER_EXTENDED_TCODE(ext_tcode);
         packet->header_length = 16;
         packet->payload = payload;
         packet->payload_length = length;
         break;
 
     case TCODE_READ_QUADLET_REQUEST:
         packet->header_length = 12;
         packet->payload_length = 0;
         break;
 
     case TCODE_READ_BLOCK_REQUEST:
         packet->header[3] =
             HEADER_DATA_LENGTH(length) |
             HEADER_EXTENDED_TCODE(ext_tcode);
         packet->header_length = 16;
         packet->payload_length = 0;
         break;
 
     default:
         WARN(1, "wrong tcode %d\n", tcode);
     }
  common:
     packet->speed = speed;
     packet->generation = generation;
     packet->ack = 0;
     packet->payload_mapped = false;
 }
 
 static int allocate_tlabel(struct fw_card *card)
 {
     int tlabel;
 
     tlabel = card->current_tlabel;
     while (card->tlabel_mask & (1ULL << tlabel)) {
         tlabel = (tlabel + 1) & 0x3f;
         if (tlabel == card->current_tlabel)
             return -EBUSY;
     }
 
     card->current_tlabel = (tlabel + 1) & 0x3f;
     card->tlabel_mask |= 1ULL << tlabel;
 
     return tlabel;
 }
 
 /**
  * fw_send_request() - submit a request packet for transmission
  * @card:       interface to send the request at
  * @t:          transaction instance to which the request belongs
  * @tcode:      transaction code
  * @destination_id: destination node ID, consisting of bus_ID and phy_ID
  * @generation:     bus generation in which request and response are valid
  * @speed:      transmission speed
  * @offset:     48bit wide offset into destination's address space
  * @payload:        data payload for the request subaction
  * @length:     length of the payload, in bytes
  * @callback:       function to be called when the transaction is completed
  * @callback_data:  data to be passed to the transaction completion callback
  *
  * Submit a request packet into the asynchronous request transmission queue.
  * Can be called from atomic context.  If you prefer a blocking API, use
  * fw_run_transaction() in a context that can sleep.
  *
  * In case of lock requests, specify one of the firewire-core specific %TCODE_
  * constants instead of %TCODE_LOCK_REQUEST in @tcode.
  *
  * Make sure that the value in @destination_id is not older than the one in
  * @generation.  Otherwise the request is in danger to be sent to a wrong node.
  *
  * In case of asynchronous stream packets i.e. %TCODE_STREAM_DATA, the caller
  * needs to synthesize @destination_id with fw_stream_packet_destination_id().
  * It will contain tag, channel, and sy data instead of a node ID then.
  *
  * The payload buffer at @data is going to be DMA-mapped except in case of
  * @length <= 8 or of local (loopback) requests.  Hence make sure that the
  * buffer complies with the restrictions of the streaming DMA mapping API.
  * @payload must not be freed before the @callback is called.
  *
  * In case of request types without payload, @data is NULL and @length is 0.
  *
  * After the transaction is completed successfully or unsuccessfully, the
  * @callback will be called.  Among its parameters is the response code which
  * is either one of the rcodes per IEEE 1394 or, in case of internal errors,
  * the firewire-core specific %RCODE_SEND_ERROR.  The other firewire-core
  * specific rcodes (%RCODE_CANCELLED, %RCODE_BUSY, %RCODE_GENERATION,
  * %RCODE_NO_ACK) denote transaction timeout, busy responder, stale request
  * generation, or missing ACK respectively.
  *
  * Note some timing corner cases:  fw_send_request() may complete much earlier
  * than when the request packet actually hits the wire.  On the other hand,
  * transaction completion and hence execution of @callback may happen even
  * before fw_send_request() returns.
  */
 void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode,
              int destination_id, int generation, int speed,
              unsigned long long offset, void *payload, size_t length,
              fw_transaction_callback_t callback, void *callback_data)
 {
     unsigned long flags;
     int tlabel;
 
     /*
      * Allocate tlabel from the bitmap and put the transaction on
      * the list while holding the card spinlock.
      */
 
     spin_lock_irqsave(&card->lock, flags);
 
     tlabel = allocate_tlabel(card);
     if (tlabel < 0) {
         spin_unlock_irqrestore(&card->lock, flags);
         callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
         return;
     }
 
     t->node_id = destination_id;
     t->tlabel = tlabel;
     t->card = card;
     t->is_split_transaction = false;
     timer_setup(&t->split_timeout_timer,
             split_transaction_timeout_callback, 0);
     t->callback = callback;
     t->callback_data = callback_data;
 
     fw_fill_request(&t->packet, tcode, t->tlabel,
             destination_id, card->node_id, generation,
             speed, offset, payload, length);
     t->packet.callback = transmit_complete_callback;
 
     list_add_tail(&t->link, &card->transaction_list);
 
     spin_unlock_irqrestore(&card->lock, flags);
 
     card->driver->send_request(card, &t->packet);
 }
 EXPORT_SYMBOL(fw_send_request);
 
 struct transaction_callback_data {
     struct completion done;
     void *payload;
     int rcode;
 };
 
 static void transaction_callback(struct fw_card *card, int rcode,
                  void *payload, size_t length, void *data)
 {
     struct transaction_callback_data *d = data;
 
     if (rcode == RCODE_COMPLETE)
         memcpy(d->payload, payload, length);
     d->rcode = rcode;
     complete(&d->done);
 }
 
 /**
  * fw_run_transaction() - send request and sleep until transaction is completed
  * @card:       card interface for this request
  * @tcode:      transaction code
  * @destination_id: destination node ID, consisting of bus_ID and phy_ID
  * @generation:     bus generation in which request and response are valid
  * @speed:      transmission speed
  * @offset:     48bit wide offset into destination's address space
  * @payload:        data payload for the request subaction
  * @length:     length of the payload, in bytes
  *
  * Returns the RCODE.  See fw_send_request() for parameter documentation.
  * Unlike fw_send_request(), @data points to the payload of the request or/and
  * to the payload of the response.  DMA mapping restrictions apply to outbound
  * request payloads of >= 8 bytes but not to inbound response payloads.
  */
 int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
                int generation, int speed, unsigned long long offset,
                void *payload, size_t length)
 {
     struct transaction_callback_data d;
     struct fw_transaction t;
 
     timer_setup_on_stack(&t.split_timeout_timer, NULL, 0);
     init_completion(&d.done);
     d.payload = payload;
     fw_send_request(card, &t, tcode, destination_id, generation, speed,
             offset, payload, length, transaction_callback, &d);
     wait_for_completion(&d.done);
     destroy_timer_on_stack(&t.split_timeout_timer);
 
     return d.rcode;
 }
 EXPORT_SYMBOL(fw_run_transaction);
 
 static DEFINE_MUTEX(phy_config_mutex);
 static DECLARE_COMPLETION(phy_config_done);
 
 static void transmit_phy_packet_callback(struct fw_packet *packet,
                      struct fw_card *card, int status)
 {
     complete(&phy_config_done);
 }
 
 static struct fw_packet phy_config_packet = {
     .header_length  = 12,
     .header[0]  = TCODE_LINK_INTERNAL << 4,
     .payload_length = 0,
     .speed      = SCODE_100,
     .callback   = transmit_phy_packet_callback,
 };
 
 void fw_send_phy_config(struct fw_card *card,
             int node_id, int generation, int gap_count)
 {
     long timeout = DIV_ROUND_UP(HZ, 10);
     u32 data = PHY_IDENTIFIER(PHY_PACKET_CONFIG);
 
     if (node_id != FW_PHY_CONFIG_NO_NODE_ID)
         data |= PHY_CONFIG_ROOT_ID(node_id);
 
     if (gap_count == FW_PHY_CONFIG_CURRENT_GAP_COUNT) {
         gap_count = card->driver->read_phy_reg(card, 1);
         if (gap_count < 0)
             return;
 
         gap_count &= 63;
         if (gap_count == 63)
             return;
     }
     data |= PHY_CONFIG_GAP_COUNT(gap_count);
 
     mutex_lock(&phy_config_mutex);
 
     phy_config_packet.header[1] = data;
     phy_config_packet.header[2] = ~data;
     phy_config_packet.generation = generation;
     reinit_completion(&phy_config_done);
 
     card->driver->send_request(card, &phy_config_packet);
     wait_for_completion_timeout(&phy_config_done, timeout);
 
     mutex_unlock(&phy_config_mutex);
 }
 
 static struct fw_address_handler *lookup_overlapping_address_handler(
     struct list_head *list, unsigned long long offset, size_t length)
 {
     struct fw_address_handler *handler;
 
     list_for_each_entry_rcu(handler, list, link) {
         if (handler->offset < offset + length &&
             offset < handler->offset + handler->length)
             return handler;
     }
 
     return NULL;
 }
 
 static bool is_enclosing_handler(struct fw_address_handler *handler,
                  unsigned long long offset, size_t length)
 {
     return handler->offset <= offset &&
         offset + length <= handler->offset + handler->length;
 }
 
 static struct fw_address_handler *lookup_enclosing_address_handler(
     struct list_head *list, unsigned long long offset, size_t length)
 {
     struct fw_address_handler *handler;
 
     list_for_each_entry_rcu(handler, list, link) {
         if (is_enclosing_handler(handler, offset, length))
             return handler;
     }
 
     return NULL;
 }
 
 static DEFINE_SPINLOCK(address_handler_list_lock);
 static LIST_HEAD(address_handler_list);
 
 const struct fw_address_region fw_high_memory_region =
     { .start = FW_MAX_PHYSICAL_RANGE, .end = 0xffffe0000000ULL, };
 EXPORT_SYMBOL(fw_high_memory_region);
 
 static const struct fw_address_region low_memory_region =
     { .start = 0x000000000000ULL, .end = FW_MAX_PHYSICAL_RANGE, };
 
 #if 0
 const struct fw_address_region fw_private_region =
     { .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
 const struct fw_address_region fw_csr_region =
     { .start = CSR_REGISTER_BASE,
       .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM_END,  };
 const struct fw_address_region fw_unit_space_region =
     { .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
 #endif  /*  0  */
 
 static bool is_in_fcp_region(u64 offset, size_t length)
 {
     return offset >= (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
         offset + length <= (CSR_REGISTER_BASE | CSR_FCP_END);
 }
 
 /**
  * fw_core_add_address_handler() - register for incoming requests
  * @handler:    callback
  * @region: region in the IEEE 1212 node space address range
  *
  * region->start, ->end, and handler->length have to be quadlet-aligned.
  *
  * When a request is received that falls within the specified address range,
  * the specified callback is invoked.  The parameters passed to the callback
  * give the details of the particular request.
  *
  * To be called in process context.
  * Return value:  0 on success, non-zero otherwise.
  *
  * The start offset of the handler's address region is determined by
  * fw_core_add_address_handler() and is returned in handler->offset.
  *
  * Address allocations are exclusive, except for the FCP registers.
  */
 int fw_core_add_address_handler(struct fw_address_handler *handler,
                 const struct fw_address_region *region)
 {
     struct fw_address_handler *other;
     int ret = -EBUSY;
 
     if (region->start & 0xffff000000000003ULL ||
         region->start >= region->end ||
         region->end   > 0x0001000000000000ULL ||
         handler->length & 3 ||
         handler->length == 0)
         return -EINVAL;
 
     spin_lock(&address_handler_list_lock);
 
     handler->offset = region->start;
     while (handler->offset + handler->length <= region->end) {
         if (is_in_fcp_region(handler->offset, handler->length))
             other = NULL;
         else
             other = lookup_overlapping_address_handler
                     (&address_handler_list,
                      handler->offset, handler->length);
         if (other != NULL) {
             handler->offset += other->length;
         } else {
             list_add_tail_rcu(&handler->link, &address_handler_list);
             ret = 0;
             break;
         }
     }
 
     spin_unlock(&address_handler_list_lock);
 
     return ret;
 }
 EXPORT_SYMBOL(fw_core_add_address_handler);
 
 /**
  * fw_core_remove_address_handler() - unregister an address handler
  * @handler: callback
  *
  * To be called in process context.
  *
  * When fw_core_remove_address_handler() returns, @handler->callback() is
  * guaranteed to not run on any CPU anymore.
  */
 void fw_core_remove_address_handler(struct fw_address_handler *handler)
 {
     spin_lock(&address_handler_list_lock);
     list_del_rcu(&handler->link);
     spin_unlock(&address_handler_list_lock);
     synchronize_rcu();
 }
 EXPORT_SYMBOL(fw_core_remove_address_handler);
 
 struct fw_request {
     struct fw_packet response;
     u32 request_header[4];
     int ack;
     u32 timestamp;
     u32 length;
     u32 data[];
 };
 
 static void free_response_callback(struct fw_packet *packet,
                    struct fw_card *card, int status)
 {
     struct fw_request *request;
 
     request = container_of(packet, struct fw_request, response);
     kfree(request);
 }
 
 int fw_get_response_length(struct fw_request *r)
 {
     int tcode, ext_tcode, data_length;
 
     tcode = HEADER_GET_TCODE(r->request_header[0]);
 
     switch (tcode) {
     case TCODE_WRITE_QUADLET_REQUEST:
     case TCODE_WRITE_BLOCK_REQUEST:
         return 0;
 
     case TCODE_READ_QUADLET_REQUEST:
         return 4;
 
     case TCODE_READ_BLOCK_REQUEST:
         data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
         return data_length;
 
     case TCODE_LOCK_REQUEST:
         ext_tcode = HEADER_GET_EXTENDED_TCODE(r->request_header[3]);
         data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
         switch (ext_tcode) {
         case EXTCODE_FETCH_ADD:
         case EXTCODE_LITTLE_ADD:
             return data_length;
         default:
             return data_length / 2;
         }
 
     default:
         WARN(1, "wrong tcode %d\n", tcode);
         return 0;
     }
 }
 
 void fw_fill_response(struct fw_packet *response, u32 *request_header,
               int rcode, void *payload, size_t length)
 {
     int tcode, tlabel, extended_tcode, source, destination;
 
     tcode          = HEADER_GET_TCODE(request_header[0]);
     tlabel         = HEADER_GET_TLABEL(request_header[0]);
     source         = HEADER_GET_DESTINATION(request_header[0]);
     destination    = HEADER_GET_SOURCE(request_header[1]);
     extended_tcode = HEADER_GET_EXTENDED_TCODE(request_header[3]);
 
     response->header[0] =
         HEADER_RETRY(RETRY_1) |
         HEADER_TLABEL(tlabel) |
         HEADER_DESTINATION(destination);
     response->header[1] =
         HEADER_SOURCE(source) |
         HEADER_RCODE(rcode);
     response->header[2] = 0;
 
     switch (tcode) {
     case TCODE_WRITE_QUADLET_REQUEST:
     case TCODE_WRITE_BLOCK_REQUEST:
         response->header[0] |= HEADER_TCODE(TCODE_WRITE_RESPONSE);
         response->header_length = 12;
         response->payload_length = 0;
         break;
 
     case TCODE_READ_QUADLET_REQUEST:
         response->header[0] |=
             HEADER_TCODE(TCODE_READ_QUADLET_RESPONSE);
         if (payload != NULL)
             response->header[3] = *(u32 *)payload;
         else
             response->header[3] = 0;
         response->header_length = 16;
         response->payload_length = 0;
         break;
 
     case TCODE_READ_BLOCK_REQUEST:
     case TCODE_LOCK_REQUEST:
         response->header[0] |= HEADER_TCODE(tcode + 2);
         response->header[3] =
             HEADER_DATA_LENGTH(length) |
             HEADER_EXTENDED_TCODE(extended_tcode);
         response->header_length = 16;
         response->payload = payload;
         response->payload_length = length;
         break;
 
     default:
         WARN(1, "wrong tcode %d\n", tcode);
     }
 
     response->payload_mapped = false;
 }
 EXPORT_SYMBOL(fw_fill_response);
 
 static u32 compute_split_timeout_timestamp(struct fw_card *card,
                        u32 request_timestamp)
 {
     unsigned int cycles;
     u32 timestamp;
 
     cycles = card->split_timeout_cycles;
     cycles += request_timestamp & 0x1fff;
 
     timestamp = request_timestamp & ~0x1fff;
     timestamp += (cycles / 8000) << 13;
     timestamp |= cycles % 8000;
 
     return timestamp;
 }
 
 static struct fw_request *allocate_request(struct fw_card *card,
                        struct fw_packet *p)
 {
     struct fw_request *request;
     u32 *data, length;
     int request_tcode;
 
     request_tcode = HEADER_GET_TCODE(p->header[0]);
     switch (request_tcode) {
     case TCODE_WRITE_QUADLET_REQUEST:
         data = &p->header[3];
         length = 4;
         break;
 
     case TCODE_WRITE_BLOCK_REQUEST:
     case TCODE_LOCK_REQUEST:
         data = p->payload;
         length = HEADER_GET_DATA_LENGTH(p->header[3]);
         break;
 
     case TCODE_READ_QUADLET_REQUEST:
         data = NULL;
         length = 4;
         break;
 
     case TCODE_READ_BLOCK_REQUEST:
         data = NULL;
         length = HEADER_GET_DATA_LENGTH(p->header[3]);
         break;
 
     default:
         fw_notice(card, "ERROR - corrupt request received - %08x %08x %08x\n",
              p->header[0], p->header[1], p->header[2]);
         return NULL;
     }
 
     request = kmalloc(sizeof(*request) + length, GFP_ATOMIC);
     if (request == NULL)
         return NULL;
 
     request->response.speed = p->speed;
     request->response.timestamp =
             compute_split_timeout_timestamp(card, p->timestamp);
     request->response.generation = p->generation;
     request->response.ack = 0;
     request->response.callback = free_response_callback;
     request->ack = p->ack;
     request->timestamp = p->timestamp;
     request->length = length;
     if (data)
         memcpy(request->data, data, length);
 
     memcpy(request->request_header, p->header, sizeof(p->header));
 
     return request;
 }
 
 void fw_send_response(struct fw_card *card,
               struct fw_request *request, int rcode)
 {
     if (WARN_ONCE(!request, "invalid for FCP address handlers"))
         return;
 
     /* unified transaction or broadcast transaction: don't respond */
     if (request->ack != ACK_PENDING ||
         HEADER_DESTINATION_IS_BROADCAST(request->request_header[0])) {
         kfree(request);
         return;
     }
 
     if (rcode == RCODE_COMPLETE)
         fw_fill_response(&request->response, request->request_header,
                  rcode, request->data,
                  fw_get_response_length(request));
     else
         fw_fill_response(&request->response, request->request_header,
                  rcode, NULL, 0);
 
     card->driver->send_response(card, &request->response);
 }
 EXPORT_SYMBOL(fw_send_response);
 
 /**
  * fw_get_request_speed() - returns speed at which the @request was received
  * @request: firewire request data
  */
 int fw_get_request_speed(struct fw_request *request)
 {
     return request->response.speed;
 }
 EXPORT_SYMBOL(fw_get_request_speed);
 
 /**
  * fw_request_get_timestamp: Get timestamp of the request.
  * @request: The opaque pointer to request structure.
  *
  * Get timestamp when 1394 OHCI controller receives the asynchronous request subaction. The
  * timestamp consists of the low order 3 bits of second field and the full 13 bits of count
  * field of isochronous cycle time register.
  *
  * Returns: timestamp of the request.
  */
 u32 fw_request_get_timestamp(const struct fw_request *request)
 {
     return request->timestamp;
 }
 EXPORT_SYMBOL_GPL(fw_request_get_timestamp);
 
 static void handle_exclusive_region_request(struct fw_card *card,
                         struct fw_packet *p,
                         struct fw_request *request,
                         unsigned long long offset)
 {
     struct fw_address_handler *handler;
     int tcode, destination, source;
 
     destination = HEADER_GET_DESTINATION(p->header[0]);
     source      = HEADER_GET_SOURCE(p->header[1]);
     tcode       = HEADER_GET_TCODE(p->header[0]);
     if (tcode == TCODE_LOCK_REQUEST)
         tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);
 
     rcu_read_lock();
     handler = lookup_enclosing_address_handler(&address_handler_list,
                            offset, request->length);
     if (handler)
         handler->address_callback(card, request,
                       tcode, destination, source,
                       p->generation, offset,
                       request->data, request->length,
                       handler->callback_data);
     rcu_read_unlock();
 
     if (!handler)
         fw_send_response(card, request, RCODE_ADDRESS_ERROR);
 }
 
 static void handle_fcp_region_request(struct fw_card *card,
                       struct fw_packet *p,
                       struct fw_request *request,
                       unsigned long long offset)
 {
     struct fw_address_handler *handler;
     int tcode, destination, source;
 
     if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
          offset != (CSR_REGISTER_BASE | CSR_FCP_RESPONSE)) ||
         request->length > 0x200) {
         fw_send_response(card, request, RCODE_ADDRESS_ERROR);
 
         return;
     }
 
     tcode       = HEADER_GET_TCODE(p->header[0]);
     destination = HEADER_GET_DESTINATION(p->header[0]);
     source      = HEADER_GET_SOURCE(p->header[1]);
 
     if (tcode != TCODE_WRITE_QUADLET_REQUEST &&
         tcode != TCODE_WRITE_BLOCK_REQUEST) {
         fw_send_response(card, request, RCODE_TYPE_ERROR);
 
         return;
     }
 
     rcu_read_lock();
     list_for_each_entry_rcu(handler, &address_handler_list, link) {
         if (is_enclosing_handler(handler, offset, request->length))
             handler->address_callback(card, NULL, tcode,
                           destination, source,
                           p->generation, offset,
                           request->data,
                           request->length,
                           handler->callback_data);
     }
     rcu_read_unlock();
 
     fw_send_response(card, request, RCODE_COMPLETE);
 }
 
 void fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
 {
     struct fw_request *request;
     unsigned long long offset;
 
     if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
         return;
 
     if (TCODE_IS_LINK_INTERNAL(HEADER_GET_TCODE(p->header[0]))) {
         fw_cdev_handle_phy_packet(card, p);
         return;
     }
 
     request = allocate_request(card, p);
     if (request == NULL) {
         /* FIXME: send statically allocated busy packet. */
         return;
     }
 
     offset = ((u64)HEADER_GET_OFFSET_HIGH(p->header[1]) << 32) |
         p->header[2];
 
     if (!is_in_fcp_region(offset, request->length))
         handle_exclusive_region_request(card, p, request, offset);
     else
         handle_fcp_region_request(card, p, request, offset);
 
 }
 EXPORT_SYMBOL(fw_core_handle_request);
 
 void fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
 {
     struct fw_transaction *t = NULL, *iter;
     unsigned long flags;
     u32 *data;
     size_t data_length;
     int tcode, tlabel, source, rcode;
 
     tcode   = HEADER_GET_TCODE(p->header[0]);
     tlabel  = HEADER_GET_TLABEL(p->header[0]);
     source  = HEADER_GET_SOURCE(p->header[1]);
     rcode   = HEADER_GET_RCODE(p->header[1]);
 
     spin_lock_irqsave(&card->lock, flags);
     list_for_each_entry(iter, &card->transaction_list, link) {
         if (iter->node_id == source && iter->tlabel == tlabel) {
             if (!try_cancel_split_timeout(iter)) {
                 spin_unlock_irqrestore(&card->lock, flags);
                 goto timed_out;
             }
             list_del_init(&iter->link);
             card->tlabel_mask &= ~(1ULL << iter->tlabel);
             t = iter;
             break;
         }
     }
     spin_unlock_irqrestore(&card->lock, flags);
 
     if (!t) {
  timed_out:
         fw_notice(card, "unsolicited response (source %x, tlabel %x)\n",
               source, tlabel);
         return;
     }
 
     /*
      * FIXME: sanity check packet, is length correct, does tcodes
      * and addresses match.
      */
 
     switch (tcode) {
     case TCODE_READ_QUADLET_RESPONSE:
         data = (u32 *) &p->header[3];
         data_length = 4;
         break;
 
     case TCODE_WRITE_RESPONSE:
         data = NULL;
         data_length = 0;
         break;
 
     case TCODE_READ_BLOCK_RESPONSE:
     case TCODE_LOCK_RESPONSE:
         data = p->payload;
         data_length = HEADER_GET_DATA_LENGTH(p->header[3]);
         break;
 
     default:
         /* Should never happen, this is just to shut up gcc. */
         data = NULL;
         data_length = 0;
         break;
     }
 
     /*
      * The response handler may be executed while the request handler
      * is still pending.  Cancel the request handler.
      */
     card->driver->cancel_packet(card, &t->packet);
 
     t->callback(card, rcode, data, data_length, t->callback_data);
 }
 EXPORT_SYMBOL(fw_core_handle_response);
 
 /**
  * fw_rcode_string - convert a firewire result code to an error description
  * @rcode: the result code
  */
 const char *fw_rcode_string(int rcode)
 {
     static const char *const names[] = {
         [RCODE_COMPLETE]       = "no error",
         [RCODE_CONFLICT_ERROR] = "conflict error",
         [RCODE_DATA_ERROR]     = "data error",
         [RCODE_TYPE_ERROR]     = "type error",
         [RCODE_ADDRESS_ERROR]  = "address error",
         [RCODE_SEND_ERROR]     = "send error",
         [RCODE_CANCELLED]      = "timeout",
         [RCODE_BUSY]           = "busy",
         [RCODE_GENERATION]     = "bus reset",
         [RCODE_NO_ACK]         = "no ack",
     };
 
     if ((unsigned int)rcode < ARRAY_SIZE(names) && names[rcode])
         return names[rcode];
     else
         return "unknown";
 }
 EXPORT_SYMBOL(fw_rcode_string);
 
 static const struct fw_address_region topology_map_region =
     { .start = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP,
       .end   = CSR_REGISTER_BASE | CSR_TOPOLOGY_MAP_END, };
 
 static void handle_topology_map(struct fw_card *card, struct fw_request *request,
         int tcode, int destination, int source, int generation,
         unsigned long long offset, void *payload, size_t length,
         void *callback_data)
 {
     int start;
 
     if (!TCODE_IS_READ_REQUEST(tcode)) {
         fw_send_response(card, request, RCODE_TYPE_ERROR);
         return;
     }
 
     if ((offset & 3) > 0 || (length & 3) > 0) {
         fw_send_response(card, request, RCODE_ADDRESS_ERROR);
         return;
     }
 
     start = (offset - topology_map_region.start) / 4;
     memcpy(payload, &card->topology_map[start], length);
 
     fw_send_response(card, request, RCODE_COMPLETE);
 }
 
 static struct fw_address_handler topology_map = {
     .length         = 0x400,
     .address_callback   = handle_topology_map,
 };
 
 static const struct fw_address_region registers_region =
     { .start = CSR_REGISTER_BASE,
       .end   = CSR_REGISTER_BASE | CSR_CONFIG_ROM, };
 
 static void update_split_timeout(struct fw_card *card)
 {
     unsigned int cycles;
 
     cycles = card->split_timeout_hi * 8000 + (card->split_timeout_lo >> 19);
 
     /* minimum per IEEE 1394, maximum which doesn't overflow OHCI */
     cycles = clamp(cycles, 800u, 3u * 8000u);
 
     card->split_timeout_cycles = cycles;
     card->split_timeout_jiffies = DIV_ROUND_UP(cycles * HZ, 8000);
 }
 
 static void handle_registers(struct fw_card *card, struct fw_request *request,
         int tcode, int destination, int source, int generation,
         unsigned long long offset, void *payload, size_t length,
         void *callback_data)
 {
     int reg = offset & ~CSR_REGISTER_BASE;
     __be32 *data = payload;
     int rcode = RCODE_COMPLETE;
     unsigned long flags;
 
     switch (reg) {
     case CSR_PRIORITY_BUDGET:
         if (!card->priority_budget_implemented) {
             rcode = RCODE_ADDRESS_ERROR;
             break;
         }
         fallthrough;
 
     case CSR_NODE_IDS:
         /*
          * per IEEE 1394-2008 8.3.22.3, not IEEE 1394.1-2004 3.2.8
          * and 9.6, but interoperable with IEEE 1394.1-2004 bridges
          */
         fallthrough;
 
     case CSR_STATE_CLEAR:
     case CSR_STATE_SET:
     case CSR_CYCLE_TIME:
     case CSR_BUS_TIME:
     case CSR_BUSY_TIMEOUT:
         if (tcode == TCODE_READ_QUADLET_REQUEST)
             *data = cpu_to_be32(card->driver->read_csr(card, reg));
         else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
             card->driver->write_csr(card, reg, be32_to_cpu(*data));
         else
             rcode = RCODE_TYPE_ERROR;
         break;
 
     case CSR_RESET_START:
         if (tcode == TCODE_WRITE_QUADLET_REQUEST)
             card->driver->write_csr(card, CSR_STATE_CLEAR,
                         CSR_STATE_BIT_ABDICATE);
         else
             rcode = RCODE_TYPE_ERROR;
         break;
 
     case CSR_SPLIT_TIMEOUT_HI:
         if (tcode == TCODE_READ_QUADLET_REQUEST) {
             *data = cpu_to_be32(card->split_timeout_hi);
         } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
             spin_lock_irqsave(&card->lock, flags);
             card->split_timeout_hi = be32_to_cpu(*data) & 7;
             update_split_timeout(card);
             spin_unlock_irqrestore(&card->lock, flags);
         } else {
             rcode = RCODE_TYPE_ERROR;
         }
         break;
 
     case CSR_SPLIT_TIMEOUT_LO:
         if (tcode == TCODE_READ_QUADLET_REQUEST) {
             *data = cpu_to_be32(card->split_timeout_lo);
         } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
             spin_lock_irqsave(&card->lock, flags);
             card->split_timeout_lo =
                     be32_to_cpu(*data) & 0xfff80000;
             update_split_timeout(card);
             spin_unlock_irqrestore(&card->lock, flags);
         } else {
             rcode = RCODE_TYPE_ERROR;
         }
         break;
 
     case CSR_MAINT_UTILITY:
         if (tcode == TCODE_READ_QUADLET_REQUEST)
             *data = card->maint_utility_register;
         else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
             card->maint_utility_register = *data;
         else
             rcode = RCODE_TYPE_ERROR;
         break;
 
     case CSR_BROADCAST_CHANNEL:
         if (tcode == TCODE_READ_QUADLET_REQUEST)
             *data = cpu_to_be32(card->broadcast_channel);
         else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
             card->broadcast_channel =
                 (be32_to_cpu(*data) & BROADCAST_CHANNEL_VALID) |
                 BROADCAST_CHANNEL_INITIAL;
         else
             rcode = RCODE_TYPE_ERROR;
         break;
 
     case CSR_BUS_MANAGER_ID:
     case CSR_BANDWIDTH_AVAILABLE:
     case CSR_CHANNELS_AVAILABLE_HI:
     case CSR_CHANNELS_AVAILABLE_LO:
         /*
          * FIXME: these are handled by the OHCI hardware and
          * the stack never sees these request. If we add
          * support for a new type of controller that doesn't
          * handle this in hardware we need to deal with these
          * transactions.
          */
         BUG();
         break;
 
     default:
         rcode = RCODE_ADDRESS_ERROR;
         break;
     }
 
     fw_send_response(card, request, rcode);
 }
 
 static struct fw_address_handler registers = {
     .length         = 0x400,
     .address_callback   = handle_registers,
 };
 
 static void handle_low_memory(struct fw_card *card, struct fw_request *request,
         int tcode, int destination, int source, int generation,
         unsigned long long offset, void *payload, size_t length,
         void *callback_data)
 {
     /*
      * This catches requests not handled by the physical DMA unit,
      * i.e., wrong transaction types or unauthorized source nodes.
      */
     fw_send_response(card, request, RCODE_TYPE_ERROR);
 }
 
 static struct fw_address_handler low_memory = {
     .length         = FW_MAX_PHYSICAL_RANGE,
     .address_callback   = handle_low_memory,
 };
 
 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
 MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
 MODULE_LICENSE("GPL");
 
 static const u32 vendor_textual_descriptor[] = {
     /* textual descriptor leaf () */
     0x00060000,
     0x00000000,
     0x00000000,
     0x4c696e75,     /* L i n u */
     0x78204669,     /* x   F i */
     0x72657769,     /* r e w i */
     0x72650000,     /* r e     */
 };
 
 static const u32 model_textual_descriptor[] = {
     /* model descriptor leaf () */
     0x00030000,
     0x00000000,
     0x00000000,
     0x4a756a75,     /* J u j u */
 };
 
 static struct fw_descriptor vendor_id_descriptor = {
     .length = ARRAY_SIZE(vendor_textual_descriptor),
     .immediate = 0x03001f11,
     .key = 0x81000000,
     .data = vendor_textual_descriptor,
 };
 
 static struct fw_descriptor model_id_descriptor = {
     .length = ARRAY_SIZE(model_textual_descriptor),
     .immediate = 0x17023901,
     .key = 0x81000000,
     .data = model_textual_descriptor,
 };
 
 static int __init fw_core_init(void)
 {
     int ret;
 
     fw_workqueue = alloc_workqueue("firewire", WQ_MEM_RECLAIM, 0);
     if (!fw_workqueue)
         return -ENOMEM;
 
     ret = bus_register(&fw_bus_type);
     if (ret < 0) {
         destroy_workqueue(fw_workqueue);
         return ret;
     }
 
     fw_cdev_major = register_chrdev(0, "firewire", &fw_device_ops);
     if (fw_cdev_major < 0) {
         bus_unregister(&fw_bus_type);
         destroy_workqueue(fw_workqueue);
         return fw_cdev_major;
     }
 
     fw_core_add_address_handler(&topology_map, &topology_map_region);
     fw_core_add_address_handler(&registers, &registers_region);
     fw_core_add_address_handler(&low_memory, &low_memory_region);
     fw_core_add_descriptor(&vendor_id_descriptor);
     fw_core_add_descriptor(&model_id_descriptor);
 
     return 0;
 }
 
 static void __exit fw_core_cleanup(void)
 {
     unregister_chrdev(fw_cdev_major, "firewire");
     bus_unregister(&fw_bus_type);
     destroy_workqueue(fw_workqueue);
     idr_destroy(&fw_device_idr);
 }
 
 module_init(fw_core_init);
 module_exit(fw_core_cleanup);

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