Date: Thu, 2 Nov 2006 21:16:08 +0100 (CET) From: Stefan Richter Subject: ieee1394: sbp2: remove superfluous comments And update and reformat remaining comments. Signed-off-by: Stefan Richter --- drivers/ieee1394/sbp2.c | 384 +++++++--------------------------------- drivers/ieee1394/sbp2.h | 80 +++----- 2 files changed, 109 insertions(+), 355 deletions(-) Index: linux/drivers/ieee1394/sbp2.h =================================================================== --- linux.orig/drivers/ieee1394/sbp2.h 2006-10-31 20:13:55.000000000 +0100 +++ linux/drivers/ieee1394/sbp2.h 2006-10-31 20:13:56.000000000 +0100 @@ -25,7 +25,7 @@ #define SBP2_DEVICE_NAME "sbp2" /* - * SBP2 specific structures and defines + * SBP-2 specific definitions */ #define ORB_DIRECTION_WRITE_TO_MEDIA 0x0 @@ -185,8 +185,9 @@ struct sbp2_status_block { u8 command_set_dependent[24]; } __attribute__((packed)); + /* - * Miscellaneous SBP2 related config rom defines + * SBP2 related configuration ROM definitions */ #define SBP2_UNIT_DIRECTORY_OFFSET_KEY 0xd1 @@ -207,19 +208,17 @@ struct sbp2_status_block { #define SBP2_UNSOLICITED_STATUS_VALUE 0xf #define SBP2_BUSY_TIMEOUT_ADDRESS 0xfffff0000210ULL +/* biggest possible value for Single Phase Retry count is 0xf */ #define SBP2_BUSY_TIMEOUT_VALUE 0xf #define SBP2_AGENT_RESET_DATA 0xf -/* - * Unit spec id and sw version entry for SBP-2 devices - */ - #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e #define SBP2_SW_VERSION_ENTRY 0x00010483 + /* - * SCSI specific stuff + * SCSI specific definitions */ #define SBP2_MAX_SG_ELEMENT_LENGTH 0xf000 @@ -237,18 +236,19 @@ struct sbp2_status_block { #define SBP2_SCSI_STATUS_COMMAND_TERMINATED 0x22 #define SBP2_SCSI_STATUS_SELECTION_TIMEOUT 0xff -/* This is the two dma types we use for cmd_dma below */ + +/* + * Representations of commands and devices + */ + enum cmd_dma_types { CMD_DMA_NONE, CMD_DMA_PAGE, CMD_DMA_SINGLE }; -/* - * Encapsulates all the info necessary for an outstanding command. - */ +/* Per SCSI command */ struct sbp2_command_info { - struct list_head list; struct sbp2_command_orb command_orb ____cacheline_aligned; dma_addr_t command_orb_dma ____cacheline_aligned; @@ -263,18 +263,17 @@ struct sbp2_command_info { enum cmd_dma_types dma_type; unsigned long dma_size; int dma_dir; - }; -struct sbp2scsi_host_info; +/* Per FireWire host */ +struct sbp2scsi_host_info { + struct hpsb_host *host; + struct list_head scsi_ids; +}; -/* - * Information needed on a per scsi id basis (one for each sbp2 device) - */ +/* Per logical unit */ struct scsi_id_instance_data { - /* - * Various sbp2 specific structures - */ + /* Operation request blocks */ struct sbp2_command_orb *last_orb; dma_addr_t last_orb_dma; struct sbp2_login_orb *login_orb; @@ -291,57 +290,49 @@ struct scsi_id_instance_data { dma_addr_t logout_orb_dma; struct sbp2_status_block status_block; - /* - * Stuff we need to know about the sbp2 device itself - */ + /* How to talk to the unit */ u64 sbp2_management_agent_addr; u64 sbp2_command_block_agent_addr; u32 speed_code; u32 max_payload_size; - /* - * Values pulled from the device's unit directory - */ + /* Pulled from the device's unit directory */ u32 sbp2_command_set_spec_id; u32 sbp2_command_set; u32 sbp2_unit_characteristics; u32 sbp2_lun; u32 sbp2_firmware_revision; - /* - * Address for the device to write status blocks to - */ + /* Address for the unit to write status blocks to */ u64 status_fifo_addr; - /* - * Waitqueue flag for logins, reconnects, logouts, query logins - */ + /* Waitqueue flag for logins, reconnects, logouts, query logins */ int access_complete:1; - /* - * Pool of command orbs, so we can have more than overlapped command per id - */ + /* Pool of command ORBs for this logical unit */ spinlock_t sbp2_command_orb_lock; struct list_head sbp2_command_orb_inuse; struct list_head sbp2_command_orb_completed; + /* Backlink to FireWire host; list of units attached to the host */ + struct sbp2scsi_host_info *hi; struct list_head scsi_list; - /* Node entry, as retrieved from NodeMgr entries */ + /* IEEE 1394 core's device representations */ struct node_entry *ne; struct unit_directory *ud; - /* A backlink to our host_info */ - struct sbp2scsi_host_info *hi; - - /* SCSI related pointers */ + /* SCSI core's device representations */ struct scsi_device *sdev; struct Scsi_Host *scsi_host; /* Device specific workarounds/brokeness */ unsigned workarounds; + /* Connection state */ atomic_t state; + + /* For deferred requests to the fetch agent */ struct work_struct protocol_work; }; @@ -352,13 +343,8 @@ enum sbp2lu_state_types { SBP2LU_STATE_IN_SHUTDOWN /* when sbp2_remove was called */ }; -/* Sbp2 host data structure (one per IEEE1394 host) */ -struct sbp2scsi_host_info { - struct hpsb_host *host; /* IEEE1394 host */ - struct list_head scsi_ids; /* List of scsi ids on this host */ -}; - -/* Flags for detected oddities and brokeness */ +/* For use in scsi_id_instance_data.workarounds and in the corresponding + * module load parameter */ #define SBP2_WORKAROUND_128K_MAX_TRANS 0x1 #define SBP2_WORKAROUND_INQUIRY_36 0x2 #define SBP2_WORKAROUND_MODE_SENSE_8 0x4 Index: linux/drivers/ieee1394/sbp2.c =================================================================== --- linux.orig/drivers/ieee1394/sbp2.c 2006-10-31 20:13:52.000000000 +0100 +++ linux/drivers/ieee1394/sbp2.c 2006-10-31 20:15:27.000000000 +0100 @@ -404,15 +404,15 @@ static int sbp2util_access_timeout(struc return leftover <= 0; } -/* Frees an allocated packet */ static void sbp2_free_packet(struct hpsb_packet *packet) { hpsb_free_tlabel(packet); hpsb_free_packet(packet); } -/* This is much like hpsb_node_write(), except it ignores the response - * subaction and returns immediately. Can be used from interrupts. +/* + * This is much like hpsb_node_write(), except it ignores the response + * subaction and returns immediately. Can be used from atomic context. */ static int sbp2util_node_write_no_wait(struct node_entry *ne, u64 addr, quadlet_t *buffer, size_t length) @@ -476,10 +476,6 @@ static void sbp2util_write_doorbell(void sbp2util_notify_fetch_agent(p, SBP2_DOORBELL_OFFSET, NULL, 4); } -/* - * This function is called to create a pool of command orbs used for - * command processing. It is called when a new sbp2 device is detected. - */ static int sbp2util_create_command_orb_pool(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; @@ -513,9 +509,6 @@ static int sbp2util_create_command_orb_p return 0; } -/* - * This function is called to delete a pool of command orbs. - */ static void sbp2util_remove_command_orb_pool(struct scsi_id_instance_data *scsi_id) { struct hpsb_host *host = scsi_id->hi->host; @@ -527,8 +520,6 @@ static void sbp2util_remove_command_orb_ if (!list_empty(&scsi_id->sbp2_command_orb_completed)) { list_for_each_safe(lh, next, &scsi_id->sbp2_command_orb_completed) { command = list_entry(lh, struct sbp2_command_info, list); - - /* Release our generic DMA's */ pci_unmap_single(host->pdev, command->command_orb_dma, sizeof(struct sbp2_command_orb), PCI_DMA_TODEVICE); @@ -543,8 +534,8 @@ static void sbp2util_remove_command_orb_ } /* - * This function finds the sbp2_command for a given outstanding command - * orb.Only looks at the inuse list. + * Finds the sbp2_command for a given outstanding command ORB. + * Only looks at the in-use list. */ static struct sbp2_command_info *sbp2util_find_command_for_orb( struct scsi_id_instance_data *scsi_id, dma_addr_t orb) @@ -566,8 +557,8 @@ static struct sbp2_command_info *sbp2uti } /* - * This function finds the sbp2_command for a given outstanding SCpnt. - * Only looks at the inuse list. + * Finds the sbp2_command for a given outstanding SCpnt. + * Only looks at the in-use list. * Must be called with scsi_id->sbp2_command_orb_lock held. */ static struct sbp2_command_info *sbp2util_find_command_for_SCpnt( @@ -582,9 +573,6 @@ static struct sbp2_command_info *sbp2uti return NULL; } -/* - * This function allocates a command orb used to send a scsi command. - */ static struct sbp2_command_info *sbp2util_allocate_command_orb( struct scsi_id_instance_data *scsi_id, struct scsi_cmnd *Current_SCpnt, @@ -609,7 +597,6 @@ static struct sbp2_command_info *sbp2uti return command; } -/* Free our DMA's */ static void sbp2util_free_command_dma(struct sbp2_command_info *command) { struct scsi_id_instance_data *scsi_id = @@ -705,7 +692,7 @@ static int sbp2_remove(struct device *de * send them. */ if (!sbp2util_node_is_available(scsi_id)) sbp2scsi_complete_all_commands(scsi_id, DID_NO_CONNECT); - /* scsi_remove_device() will trigger shutdown functions of SCSI + /* scsi_remove_device() may trigger shutdown functions of SCSI * highlevel drivers which would deadlock if blocked. */ atomic_set(&scsi_id->state, SBP2LU_STATE_IN_SHUTDOWN); scsi_unblock_requests(scsi_id->scsi_host); @@ -727,12 +714,9 @@ static int sbp2_update(struct unit_direc struct scsi_id_instance_data *scsi_id = ud->device.driver_data; if (sbp2_reconnect_device(scsi_id)) { - - /* - * Ok, reconnect has failed. Perhaps we didn't - * reconnect fast enough. Try doing a regular login, but - * first do a logout just in case of any weirdness. - */ + /* Reconnect has failed. Perhaps we didn't reconnect fast + * enough. Try a regular login, but first log out just in + * case of any weirdness. */ sbp2_logout_device(scsi_id); if (sbp2_login_device(scsi_id)) { @@ -743,18 +727,12 @@ static int sbp2_update(struct unit_direc } } - /* Set max retries to something large on the device. */ sbp2_set_busy_timeout(scsi_id); - - /* Do a SBP-2 fetch agent reset. */ sbp2_agent_reset(scsi_id, 1); - - /* Get the max speed and packet size that we can use. */ sbp2_max_speed_and_size(scsi_id); - /* Complete any pending commands with busy (so they get - * retried) and remove them from our queue - */ + /* Complete any pending commands with busy (so they get retried) + * and remove them from our queue. */ sbp2scsi_complete_all_commands(scsi_id, DID_BUS_BUSY); /* Accept new commands unless there was another bus reset in the @@ -766,8 +744,6 @@ static int sbp2_update(struct unit_direc return 0; } -/* This functions is called by the sbp2_probe, for each new device. We now - * allocate one scsi host for each scsi_id (unit directory). */ static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud) { struct sbp2scsi_host_info *hi; @@ -843,7 +819,6 @@ static struct scsi_id_instance_data *sbp goto failed_alloc; } - /* Register our host with the SCSI stack. */ scsi_host = scsi_host_alloc(&scsi_driver_template, sizeof(unsigned long)); if (!scsi_host) { @@ -882,16 +857,11 @@ static void sbp2_host_reset(struct hpsb_ } } -/* - * This function is where we first pull the node unique ids, and then - * allocate memory and register a SBP-2 device. - */ static int sbp2_start_device(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; int error; - /* Login FIFO DMA */ scsi_id->login_response = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_login_response), @@ -899,7 +869,6 @@ static int sbp2_start_device(struct scsi if (!scsi_id->login_response) goto alloc_fail; - /* Query logins ORB DMA */ scsi_id->query_logins_orb = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_query_logins_orb), @@ -907,7 +876,6 @@ static int sbp2_start_device(struct scsi if (!scsi_id->query_logins_orb) goto alloc_fail; - /* Query logins response DMA */ scsi_id->query_logins_response = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_query_logins_response), @@ -915,7 +883,6 @@ static int sbp2_start_device(struct scsi if (!scsi_id->query_logins_response) goto alloc_fail; - /* Reconnect ORB DMA */ scsi_id->reconnect_orb = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_reconnect_orb), @@ -923,7 +890,6 @@ static int sbp2_start_device(struct scsi if (!scsi_id->reconnect_orb) goto alloc_fail; - /* Logout ORB DMA */ scsi_id->logout_orb = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_logout_orb), @@ -931,7 +897,6 @@ static int sbp2_start_device(struct scsi if (!scsi_id->logout_orb) goto alloc_fail; - /* Login ORB DMA */ scsi_id->login_orb = pci_alloc_consistent(hi->host->pdev, sizeof(struct sbp2_login_orb), @@ -939,51 +904,28 @@ static int sbp2_start_device(struct scsi if (!scsi_id->login_orb) goto alloc_fail; - /* - * Create our command orb pool - */ if (sbp2util_create_command_orb_pool(scsi_id)) { SBP2_ERR("sbp2util_create_command_orb_pool failed!"); sbp2_remove_device(scsi_id); return -ENOMEM; } - /* Schedule a timeout here. The reason is that we may be so close - * to a bus reset, that the device is not available for logins. - * This can happen when the bus reset is caused by the host - * connected to the sbp2 device being removed. That host would - * have a certain amount of time to relogin before the sbp2 device - * allows someone else to login instead. One second makes sense. */ + /* Wait a second before trying to log in. Previously logged in + * initiators need a chance to reconnect. */ if (msleep_interruptible(1000)) { sbp2_remove_device(scsi_id); return -EINTR; } - /* - * Login to the sbp-2 device - */ if (sbp2_login_device(scsi_id)) { - /* Login failed, just remove the device. */ sbp2_remove_device(scsi_id); return -EBUSY; } - /* - * Set max retries to something large on the device - */ sbp2_set_busy_timeout(scsi_id); - - /* - * Do a SBP-2 fetch agent reset - */ sbp2_agent_reset(scsi_id, 1); - - /* - * Get the max speed and packet size that we can use - */ sbp2_max_speed_and_size(scsi_id); - /* Add this device to the scsi layer now */ error = scsi_add_device(scsi_id->scsi_host, 0, scsi_id->ud->id, 0); if (error) { SBP2_ERR("scsi_add_device failed"); @@ -1000,9 +942,6 @@ alloc_fail: return -ENOMEM; } -/* - * This function removes an sbp2 device from the sbp2scsi_host_info struct. - */ static void sbp2_remove_device(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi; @@ -1012,7 +951,6 @@ static void sbp2_remove_device(struct sc hi = scsi_id->hi; - /* This will remove our scsi device aswell */ if (scsi_id->scsi_host) { scsi_remove_host(scsi_id->scsi_host); scsi_host_put(scsi_id->scsi_host); @@ -1067,33 +1005,25 @@ static void sbp2_remove_device(struct sc #ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA /* - * This function deals with physical dma write requests (for adapters that do not support - * physical dma in hardware). Mostly just here for debugging... + * Deal with write requests on adapters which do not support physical DMA or + * have it switched off. */ static int sbp2_handle_physdma_write(struct hpsb_host *host, int nodeid, int destid, quadlet_t *data, u64 addr, size_t length, u16 flags) { - - /* - * Manually put the data in the right place. - */ memcpy(bus_to_virt((u32) addr), data, length); return RCODE_COMPLETE; } /* - * This function deals with physical dma read requests (for adapters that do not support - * physical dma in hardware). Mostly just here for debugging... + * Deal with read requests on adapters which do not support physical DMA or + * have it switched off. */ static int sbp2_handle_physdma_read(struct hpsb_host *host, int nodeid, quadlet_t *data, u64 addr, size_t length, u16 flags) { - - /* - * Grab data from memory and send a read response. - */ memcpy(data, bus_to_virt((u32) addr), length); return RCODE_COMPLETE; } @@ -1103,10 +1033,6 @@ static int sbp2_handle_physdma_read(stru * SBP-2 protocol related section **************************************/ -/* - * This function queries the device for the maximum concurrent logins it - * supports. - */ static int sbp2_query_logins(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; @@ -1172,10 +1098,6 @@ static int sbp2_query_logins(struct scsi return 0; } -/* - * This function is called in order to login to a particular SBP-2 device, - * after a bus reset. - */ static int sbp2_login_device(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; @@ -1191,17 +1113,18 @@ static int sbp2_login_device(struct scsi } } - /* Set-up login ORB, assume no password */ + /* assume no password */ scsi_id->login_orb->password_hi = 0; scsi_id->login_orb->password_lo = 0; scsi_id->login_orb->login_response_lo = scsi_id->login_response_dma; scsi_id->login_orb->login_response_hi = ORB_SET_NODE_ID(hi->host->node_id); - scsi_id->login_orb->lun_misc = ORB_SET_FUNCTION(SBP2_LOGIN_REQUEST); - scsi_id->login_orb->lun_misc |= ORB_SET_RECONNECT(0); /* One second reconnect time */ - scsi_id->login_orb->lun_misc |= ORB_SET_EXCLUSIVE(exclusive_login); /* Exclusive access to device */ - scsi_id->login_orb->lun_misc |= ORB_SET_NOTIFY(1); /* Notify us of login complete */ + + /* one second reconnect time */ + scsi_id->login_orb->lun_misc |= ORB_SET_RECONNECT(0); + scsi_id->login_orb->lun_misc |= ORB_SET_EXCLUSIVE(exclusive_login); + scsi_id->login_orb->lun_misc |= ORB_SET_NOTIFY(1); scsi_id->login_orb->lun_misc |= ORB_SET_LUN(scsi_id->sbp2_lun); scsi_id->login_orb->passwd_resp_lengths = @@ -1222,17 +1145,13 @@ static int sbp2_login_device(struct scsi hpsb_node_write(scsi_id->ne, scsi_id->sbp2_management_agent_addr, data, 8); - /* - * Wait for login status (up to 20 seconds)... - */ + /* wait up to 20 seconds for login status */ if (sbp2util_access_timeout(scsi_id, 20*HZ)) { SBP2_ERR("Error logging into SBP-2 device - timed out"); return -EIO; } - /* - * Sanity. Make sure status returned matches login orb. - */ + /* make sure that the returned status matches the login ORB */ if (scsi_id->status_block.ORB_offset_lo != scsi_id->login_orb_dma) { SBP2_ERR("Error logging into SBP-2 device - timed out"); return -EIO; @@ -1243,15 +1162,7 @@ static int sbp2_login_device(struct scsi return -EIO; } - /* - * Byte swap the login response, for use when reconnecting or - * logging out. - */ sbp2util_cpu_to_be32_buffer(scsi_id->login_response, sizeof(struct sbp2_login_response)); - - /* - * Grab our command block agent address from the login response. - */ scsi_id->sbp2_command_block_agent_addr = ((u64)scsi_id->login_response->command_block_agent_hi) << 32; scsi_id->sbp2_command_block_agent_addr |= ((u64)scsi_id->login_response->command_block_agent_lo); @@ -1261,19 +1172,12 @@ static int sbp2_login_device(struct scsi return 0; } -/* - * This function is called in order to logout from a particular SBP-2 - * device, usually called during driver unload. - */ static int sbp2_logout_device(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; quadlet_t data[2]; int error; - /* - * Set-up logout ORB - */ scsi_id->logout_orb->reserved1 = 0x0; scsi_id->logout_orb->reserved2 = 0x0; scsi_id->logout_orb->reserved3 = 0x0; @@ -1281,8 +1185,6 @@ static int sbp2_logout_device(struct scs scsi_id->logout_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_LOGOUT_REQUEST); scsi_id->logout_orb->login_ID_misc |= ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID); - - /* Notify us when complete */ scsi_id->logout_orb->login_ID_misc |= ORB_SET_NOTIFY(1); scsi_id->logout_orb->reserved5 = 0x0; @@ -1291,14 +1193,8 @@ static int sbp2_logout_device(struct scs scsi_id->logout_orb->status_fifo_lo = ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr); - /* - * Byte swap ORB if necessary - */ sbp2util_cpu_to_be32_buffer(scsi_id->logout_orb, sizeof(struct sbp2_logout_orb)); - /* - * Ok, let's write to the target's management agent register - */ data[0] = ORB_SET_NODE_ID(hi->host->node_id); data[1] = scsi_id->logout_orb_dma; sbp2util_cpu_to_be32_buffer(data, 8); @@ -1308,7 +1204,7 @@ static int sbp2_logout_device(struct scs if (error) return error; - /* Wait for device to logout...1 second. */ + /* wait up to 1 second for the device to complete logout */ if (sbp2util_access_timeout(scsi_id, HZ)) return -EIO; @@ -1316,19 +1212,12 @@ static int sbp2_logout_device(struct scs return 0; } -/* - * This function is called in order to reconnect to a particular SBP-2 - * device, after a bus reset. - */ static int sbp2_reconnect_device(struct scsi_id_instance_data *scsi_id) { struct sbp2scsi_host_info *hi = scsi_id->hi; quadlet_t data[2]; int error; - /* - * Set-up reconnect ORB - */ scsi_id->reconnect_orb->reserved1 = 0x0; scsi_id->reconnect_orb->reserved2 = 0x0; scsi_id->reconnect_orb->reserved3 = 0x0; @@ -1337,8 +1226,6 @@ static int sbp2_reconnect_device(struct scsi_id->reconnect_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_RECONNECT_REQUEST); scsi_id->reconnect_orb->login_ID_misc |= ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID); - - /* Notify us when complete */ scsi_id->reconnect_orb->login_ID_misc |= ORB_SET_NOTIFY(1); scsi_id->reconnect_orb->reserved5 = 0x0; @@ -1347,9 +1234,6 @@ static int sbp2_reconnect_device(struct scsi_id->reconnect_orb->status_fifo_lo = ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr); - /* - * Byte swap ORB if necessary - */ sbp2util_cpu_to_be32_buffer(scsi_id->reconnect_orb, sizeof(struct sbp2_reconnect_orb)); data[0] = ORB_SET_NODE_ID(hi->host->node_id); @@ -1361,17 +1245,13 @@ static int sbp2_reconnect_device(struct if (error) return error; - /* - * Wait for reconnect status (up to 1 second)... - */ + /* wait up to 1 second for reconnect status */ if (sbp2util_access_timeout(scsi_id, HZ)) { SBP2_ERR("Error reconnecting to SBP-2 device - timed out"); return -EIO; } - /* - * Sanity. Make sure status returned matches reconnect orb. - */ + /* make sure that the returned status matches the reconnect ORB */ if (scsi_id->status_block.ORB_offset_lo != scsi_id->reconnect_orb_dma) { SBP2_ERR("Error reconnecting to SBP-2 device - timed out"); return -EIO; @@ -1387,8 +1267,8 @@ static int sbp2_reconnect_device(struct } /* - * This function is called in order to set the busy timeout (number of - * retries to attempt) on the sbp2 device. + * Set the target node's Single Phase Retry limit. Affects the target's retry + * behaviour if our node is too busy to accept requests. */ static int sbp2_set_busy_timeout(struct scsi_id_instance_data *scsi_id) { @@ -1400,11 +1280,6 @@ static int sbp2_set_busy_timeout(struct return 0; } -/* - * This function is called to parse sbp2 device's config rom unit - * directory. Used to determine things like sbp2 management agent offset, - * and command set used (SCSI or RBC). - */ static void sbp2_parse_unit_directory(struct scsi_id_instance_data *scsi_id, struct unit_directory *ud) { @@ -1422,12 +1297,10 @@ static void sbp2_parse_unit_directory(st unit_characteristics = 0x0; firmware_revision = 0x0; - /* Handle different fields in the unit directory, based on keys */ csr1212_for_each_dir_entry(ud->ne->csr, kv, ud->ud_kv, dentry) { switch (kv->key.id) { case CSR1212_KV_ID_DEPENDENT_INFO: if (kv->key.type == CSR1212_KV_TYPE_CSR_OFFSET) - /* Save off the management agent address */ management_agent_addr = CSR1212_REGISTER_SPACE_BASE + (kv->value.csr_offset << 2); @@ -1438,29 +1311,27 @@ static void sbp2_parse_unit_directory(st break; case SBP2_COMMAND_SET_SPEC_ID_KEY: - /* Command spec organization */ command_set_spec_id = kv->value.immediate; break; case SBP2_COMMAND_SET_KEY: - /* Command set used by sbp2 device */ command_set = kv->value.immediate; break; case SBP2_UNIT_CHARACTERISTICS_KEY: - /* - * Unit characterisitcs (orb related stuff - * that I'm not yet paying attention to) - */ + /* FIXME: This is ignored so far. + * See SBP-2 clause 7.4.8. */ unit_characteristics = kv->value.immediate; break; case SBP2_FIRMWARE_REVISION_KEY: - /* Firmware revision */ firmware_revision = kv->value.immediate; break; default: + /* FIXME: Check for SBP2_DEVICE_TYPE_AND_LUN_KEY. + * Its "ordered" bit has consequences for command ORB + * list handling. See SBP-2 clauses 4.6, 7.4.11, 10.2 */ break; } } @@ -1536,7 +1407,6 @@ static int sbp2_max_speed_and_size(struc scsi_id->speed_code = hi->host->speed[NODEID_TO_NODE(scsi_id->ne->nodeid)]; - /* Bump down our speed if the user requested it */ if (scsi_id->speed_code > max_speed) { scsi_id->speed_code = max_speed; SBP2_INFO("Reducing speed to %s", hpsb_speedto_str[max_speed]); @@ -1563,9 +1433,6 @@ static int sbp2_max_speed_and_size(struc return 0; } -/* - * This function is called in order to perform a SBP-2 agent reset. - */ static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait) { quadlet_t data; @@ -1590,9 +1457,7 @@ static int sbp2_agent_reset(struct scsi_ return -EIO; } - /* - * Need to make sure orb pointer is written on next command - */ + /* make sure that the ORB_POINTER is written on next command */ spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags); scsi_id->last_orb = NULL; spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags); @@ -1612,7 +1477,7 @@ static void sbp2_prep_command_orb_sg(str orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id); orb->misc |= ORB_SET_DIRECTION(orb_direction); - /* Special case if only one element (and less than 64KB in size) */ + /* special case if only one element (and less than 64KB in size) */ if ((scsi_use_sg == 1) && (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) { @@ -1642,10 +1507,8 @@ static void sbp2_prep_command_orb_sg(str orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1); orb->data_descriptor_lo = command->sge_dma; - /* - * Loop through and fill out our sbp-2 page tables - * (and split up anything too large) - */ + /* loop through and fill out our SBP-2 page tables + * (and split up anything too large) */ for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) { sg_len = sg_dma_len(sgpnt); sg_addr = sg_dma_address(sgpnt); @@ -1665,10 +1528,8 @@ static void sbp2_prep_command_orb_sg(str } } - /* Number of page table (s/g) elements */ orb->misc |= ORB_SET_DATA_SIZE(sg_count); - /* Byte swap page tables if necessary */ sbp2util_cpu_to_be32_buffer(sg_element, (sizeof(struct sbp2_unrestricted_page_table)) * sg_count); @@ -1692,34 +1553,25 @@ static void sbp2_prep_command_orb_no_sg( orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id); orb->misc |= ORB_SET_DIRECTION(orb_direction); - /* - * Handle case where we get a command w/o s/g enabled (but - * check for transfers larger than 64K) - */ + /* handle case where we get a command w/o s/g enabled + * (but check for transfers larger than 64K) */ if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) { orb->data_descriptor_lo = command->cmd_dma; orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen); } else { + /* The buffer is too large. Turn this into page tables. */ + struct sbp2_unrestricted_page_table *sg_element = &command->scatter_gather_element[0]; u32 sg_count, sg_len; dma_addr_t sg_addr; - /* - * Need to turn this into page tables, since the - * buffer is too large. - */ orb->data_descriptor_lo = command->sge_dma; - - /* Use page tables (s/g) */ orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1); - /* - * fill out our sbp-2 page tables (and split up - * the large buffer) - */ + /* fill out our SBP-2 page tables; split up the large buffer */ sg_count = 0; sg_len = scsi_request_bufflen; sg_addr = command->cmd_dma; @@ -1738,20 +1590,14 @@ static void sbp2_prep_command_orb_no_sg( sg_count++; } - /* Number of page table (s/g) elements */ orb->misc |= ORB_SET_DATA_SIZE(sg_count); - /* Byte swap page tables if necessary */ sbp2util_cpu_to_be32_buffer(sg_element, (sizeof(struct sbp2_unrestricted_page_table)) * sg_count); } } -/* - * This function is called to create the actual command orb and s/g list - * out of the scsi command itself. - */ static void sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id, struct sbp2_command_info *command, unchar *scsi_cmd, @@ -1766,7 +1612,7 @@ static void sbp2_create_command_orb(stru u32 orb_direction; /* - * Set-up our command ORB.. + * Set-up our command ORB. * * NOTE: We're doing unrestricted page tables (s/g), as this is * best performance (at least with the devices I have). This means @@ -1777,7 +1623,7 @@ static void sbp2_create_command_orb(stru command_orb->next_ORB_lo = 0x0; command_orb->misc = ORB_SET_MAX_PAYLOAD(scsi_id->max_payload_size); command_orb->misc |= ORB_SET_SPEED(scsi_id->speed_code); - command_orb->misc |= ORB_SET_NOTIFY(1); /* Notify us when complete */ + command_orb->misc |= ORB_SET_NOTIFY(1); if (dma_dir == DMA_NONE) orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER; @@ -1790,7 +1636,7 @@ static void sbp2_create_command_orb(stru orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER; } - /* Set-up our pagetable stuff */ + /* set up our page table stuff */ if (orb_direction == ORB_DIRECTION_NO_DATA_TRANSFER) { command_orb->data_descriptor_hi = 0x0; command_orb->data_descriptor_lo = 0x0; @@ -1803,17 +1649,12 @@ static void sbp2_create_command_orb(stru orb_direction, scsi_request_bufflen, scsi_request_buffer, dma_dir); - /* Byte swap command ORB if necessary */ sbp2util_cpu_to_be32_buffer(command_orb, sizeof(struct sbp2_command_orb)); - /* Put our scsi command in the command ORB */ memset(command_orb->cdb, 0, 12); memcpy(command_orb->cdb, scsi_cmd, COMMAND_SIZE(*scsi_cmd)); } -/* - * This function is called in order to begin a regular SBP-2 command. - */ static void sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id, struct sbp2_command_info *command) { @@ -1832,9 +1673,8 @@ static void sbp2_link_orb_command(struct pci_dma_sync_single_for_device(hi->host->pdev, command->sge_dma, sizeof(command->scatter_gather_element), PCI_DMA_BIDIRECTIONAL); - /* - * Check to see if there are any previous orbs to use - */ + + /* check to see if there are any previous orbs to use */ spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags); last_orb = scsi_id->last_orb; last_orb_dma = scsi_id->last_orb_dma; @@ -1892,9 +1732,6 @@ static void sbp2_link_orb_command(struct } } -/* - * This function is called in order to begin a regular SBP-2 command. - */ static int sbp2_send_command(struct scsi_id_instance_data *scsi_id, struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *)) @@ -1903,23 +1740,13 @@ static int sbp2_send_command(struct scsi unsigned int request_bufflen = SCpnt->request_bufflen; struct sbp2_command_info *command; - /* - * Allocate a command orb and s/g structure - */ command = sbp2util_allocate_command_orb(scsi_id, SCpnt, done); if (!command) return -EIO; - /* - * Now actually fill in the comamnd orb and sbp2 s/g list - */ sbp2_create_command_orb(scsi_id, command, cmd, SCpnt->use_sg, request_bufflen, SCpnt->request_buffer, SCpnt->sc_data_direction); - - /* - * Link up the orb, and ring the doorbell if needed - */ sbp2_link_orb_command(scsi_id, command); return 0; @@ -1930,9 +1757,7 @@ static int sbp2_send_command(struct scsi */ static unsigned int sbp2_status_to_sense_data(unchar *sbp2_status, unchar *sense_data) { - /* - * Ok, it's pretty ugly... ;-) - */ + /* OK, it's pretty ugly... ;-) */ sense_data[0] = 0x70; sense_data[1] = 0x0; sense_data[2] = sbp2_status[9]; @@ -1950,12 +1775,9 @@ static unsigned int sbp2_status_to_sense sense_data[14] = sbp2_status[20]; sense_data[15] = sbp2_status[21]; - return sbp2_status[8] & 0x3f; /* return scsi status */ + return sbp2_status[8] & 0x3f; } -/* - * This function deals with status writes from the SBP-2 device - */ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid, int destid, quadlet_t *data, u64 addr, size_t length, u16 fl) @@ -1981,10 +1803,8 @@ static int sbp2_handle_status_write(stru SBP2_ERR("host info is NULL - this is bad!"); return RCODE_ADDRESS_ERROR; } - /* - * Find our scsi_id structure by looking at the status fifo address - * written to by the sbp2 device. - */ + + /* Find the unit which wrote the status. */ list_for_each_entry(scsi_id_tmp, &hi->scsi_ids, scsi_list) { if (scsi_id_tmp->ne->nodeid == nodeid && scsi_id_tmp->status_fifo_addr == addr) { @@ -1997,20 +1817,16 @@ static int sbp2_handle_status_write(stru return RCODE_ADDRESS_ERROR; } - /* - * Put response into scsi_id status fifo buffer. The first two bytes + /* Put response into scsi_id status fifo buffer. The first two bytes * come in big endian bit order. Often the target writes only a * truncated status block, minimally the first two quadlets. The rest - * is implied to be zeros. - */ + * is implied to be zeros. */ sb = &scsi_id->status_block; memset(sb->command_set_dependent, 0, sizeof(sb->command_set_dependent)); memcpy(sb, data, length); sbp2util_be32_to_cpu_buffer(sb, 8); - /* - * Ignore unsolicited status. Handle command ORB status. - */ + /* Ignore unsolicited status. Handle command ORB status. */ if (unlikely(STATUS_GET_SRC(sb->ORB_offset_hi_misc) == 2)) command = NULL; else @@ -2023,10 +1839,7 @@ static int sbp2_handle_status_write(stru pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma, sizeof(command->scatter_gather_element), PCI_DMA_BIDIRECTIONAL); - /* - * Matched status with command, now grab scsi command pointers - * and check status. - */ + /* Grab SCSI command pointers and check status. */ /* * FIXME: If the src field in the status is 1, the ORB DMA must * not be reused until status for a subsequent ORB is received. @@ -2048,37 +1861,28 @@ static int sbp2_handle_status_write(stru SBP2_SCSI_STATUS_BUSY : SBP2_SCSI_STATUS_COMMAND_TERMINATED; } - /* - * See if the target stored any scsi status information. - */ + if (STATUS_GET_LEN(h) > 1) scsi_status = sbp2_status_to_sense_data( (unchar *)sb, SCpnt->sense_buffer); - /* - * Check to see if the dead bit is set. If so, we'll - * have to initiate a fetch agent reset. - */ + if (STATUS_TEST_DEAD(h)) sbp2_agent_reset(scsi_id, 0); } - /* - * Check here to see if there are no commands in-use. If there + /* Check here to see if there are no commands in-use. If there * are none, we know that the fetch agent left the active state * _and_ that we did not reactivate it yet. Therefore clear * last_orb so that next time we write directly to the * ORB_POINTER register. That way the fetch agent does not need - * to refetch the next_ORB. - */ + * to refetch the next_ORB. */ spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags); if (list_empty(&scsi_id->sbp2_command_orb_inuse)) scsi_id->last_orb = NULL; spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags); } else { - /* - * It's probably a login/logout/reconnect status. - */ + /* It's probably status after a management request. */ if ((sb->ORB_offset_lo == scsi_id->reconnect_orb_dma) || (sb->ORB_offset_lo == scsi_id->login_orb_dma) || (sb->ORB_offset_lo == scsi_id->query_logins_orb_dma) || @@ -2098,10 +1902,6 @@ static int sbp2_handle_status_write(stru * SCSI interface related section **************************************/ -/* - * This routine is the main request entry routine for doing I/O. It is - * called from the scsi stack directly. - */ static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *)) { @@ -2120,17 +1920,13 @@ static int sbp2scsi_queuecommand(struct goto done; } - /* - * Until we handle multiple luns, just return selection time-out - * to any IO directed at non-zero LUNs - */ + /* Multiple units are currently represented to the SCSI core as separate + * targets, not as one target with multiple LUs. Therefore return + * selection time-out to any IO directed at non-zero LUNs. */ if (SCpnt->device->lun) goto done; - /* - * Check for request sense command, and handle it here - * (autorequest sense) - */ + /* handle the request sense command here (auto-request sense) */ if (SCpnt->cmnd[0] == REQUEST_SENSE) { memcpy(SCpnt->request_buffer, SCpnt->sense_buffer, SCpnt->request_bufflen); memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer)); @@ -2138,28 +1934,20 @@ static int sbp2scsi_queuecommand(struct return 0; } - /* - * Check to see if we are in the middle of a bus reset. - */ if (!hpsb_node_entry_valid(scsi_id->ne)) { SBP2_ERR("Bus reset in progress - rejecting command"); result = DID_BUS_BUSY << 16; goto done; } - /* - * Bidirectional commands are not yet implemented, - * and unknown transfer direction not handled. - */ + /* Bidirectional commands are not yet implemented, + * and unknown transfer direction not handled. */ if (SCpnt->sc_data_direction == DMA_BIDIRECTIONAL) { SBP2_ERR("Cannot handle DMA_BIDIRECTIONAL - rejecting command"); result = DID_ERROR << 16; goto done; } - /* - * Try and send our SCSI command - */ if (sbp2_send_command(scsi_id, SCpnt, done)) { SBP2_ERR("Error sending SCSI command"); sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_SELECTION_TIMEOUT, @@ -2173,10 +1961,6 @@ done: return 0; } -/* - * This function is called in order to complete all outstanding SBP-2 - * commands (in case of resets, etc.). - */ static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id, u32 status) { @@ -2207,25 +1991,17 @@ static void sbp2scsi_complete_all_comman } /* - * This function is called in order to complete a regular SBP-2 command. - * - * This can be called in interrupt context. + * Complete a regular SCSI command. Can be called in atomic context. */ static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id, u32 scsi_status, struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *)) { - /* - * Sanity - */ if (!SCpnt) { SBP2_ERR("SCpnt is NULL"); return; } - /* - * Switch on scsi status - */ switch (scsi_status) { case SBP2_SCSI_STATUS_GOOD: SCpnt->result = DID_OK << 16; @@ -2259,19 +2035,15 @@ static void sbp2scsi_complete_command(st SCpnt->result = DID_ERROR << 16; } - /* - * If a bus reset is in progress and there was an error, complete - * the command as busy so that it will get retried. - */ + /* If a bus reset is in progress and there was an error, complete + * the command as busy so that it will get retried. */ if (!hpsb_node_entry_valid(scsi_id->ne) && (scsi_status != SBP2_SCSI_STATUS_GOOD)) { SBP2_ERR("Completing command with busy (bus reset)"); SCpnt->result = DID_BUS_BUSY << 16; } - /* - * Tell scsi stack that we're done with this command - */ + /* Tell the SCSI stack that we're done with this command. */ done(SCpnt); } @@ -2311,8 +2083,8 @@ static void sbp2scsi_slave_destroy(struc } /* - * Called by scsi stack when something has really gone wrong. Usually - * called when a command has timed-out for some reason. + * Called by scsi stack when something has really gone wrong. + * Usually called when a command has timed-out for some reason. */ static int sbp2scsi_abort(struct scsi_cmnd *SCpnt) { @@ -2401,7 +2173,6 @@ static int sbp2_module_init(void) { int ret; - /* Module load debug option to force one command at a time (serializing I/O) */ if (serialize_io) { scsi_driver_template.can_queue = 1; scsi_driver_template.cmd_per_lun = 1; @@ -2412,16 +2183,13 @@ static int sbp2_module_init(void) max_sectors = 128 * 1024 / 512; scsi_driver_template.max_sectors = max_sectors; - /* Register our high level driver with 1394 stack */ hpsb_register_highlevel(&sbp2_highlevel); - ret = hpsb_register_protocol(&sbp2_driver); if (ret) { SBP2_ERR("Failed to register protocol"); hpsb_unregister_highlevel(&sbp2_highlevel); return ret; } - return 0; }