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path: root/drivers/scsi/libfc/fc_exch.c (follow)
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2009-09-05[SCSI] fcoe, libfc: fully makes use of per cpu exch pool and then removes em_lockVasu Dev1-89/+100
1. Updates fcoe_rcv() to queue incoming frames to the fcoe per cpu thread on which this frame's exch was originated and simply use current cpu for request exch not originated by initiator. It is redundant to add this code under CONFIG_SMP, so removes CONFIG_SMP uses around this code. 2. Updates fc_exch_em_alloc, fc_exch_delete, fc_exch_find to use per cpu exch pools, here fc_exch_delete is rename of older fc_exch_mgr_delete_ep since ep/exch are now deleted in pools of EM and so brief new name is sufficient and better name. Updates these functions to map exch id to their index into exch pool using fc_cpu_mask, fc_cpu_order and EM min_xid. This mapping is as per detailed explanation about this in last patch and basically this is just as lower fc_cpu_mask bits of exch id as cpu number and upper bit sum of EM min_xid and exch index in pool. Uses pool next_index to keep track of exch allocation from pool along with pool_max_index as upper bound of exches array in pool. 3. Adds exch pool ptr to fc_exch to free exch to its pool in fc_exch_delete. 4. Updates fc_exch_mgr_reset to reset all exch pools of an EM, this required adding fc_exch_pool_reset func to reset exches in pool and then have fc_exch_mgr_reset call fc_exch_pool_reset for each pool within each EM for a lport. 5. Removes no longer needed exches array, em_lock, next_xid, and total_exches from struct fc_exch_mgr, these are not needed after use of per cpu exch pool, also removes not used max_read, last_read from struct fc_exch_mgr. 6. Updates locking notes for exch pool lock with fc_exch lock and uses pool lock in exch allocation, lookup and reset. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-09-05[SCSI] fcoe, libfc: adds per cpu exch pool within exchange manager(EM)Vasu Dev1-3/+86
Adds per cpu exch pool for these reasons:- 1. Currently an EM instance is shared across all cpus to manage all exches for all cpus. This required em_lock across all cpus for an exch alloc, free, lookup and reset each frame and that made em_lock expensive, so instead having per cpu exch pool with their own per cpu pool lock will likely reduce locking contention in fast path for an exch alloc, free and lookup. 2. Per cpu exch pool will likely improve cache hit ratio since all frames of an exch will be processed on the same cpu on which exch originated. This patch is only prep work to help in keeping complexity of next patch low, so this patch only sets up per cpu exch pool and related helper funcs to be used by next patch. The next patch fully makes use of per cpu exch pool in all code paths ie. tx, rx and reset. Divides per EM exch id range equally across all cpus to setup per cpu exch pool. This division is such that lower bits of exch id carries cpu number info on which exch originated, later a simple bitwise AND operation on exch id of incoming frame with fc_cpu_mask retrieves cpu number info to direct all frames to same cpu on which exch originated. This required a global fc_cpu_mask and fc_cpu_order initialized to max possible cpus number nr_cpu_ids rounded up to 2's power, this will be used in mapping exch id and exch ptr array index in pool during exch allocation, find or reset code paths. Adds a check in fc_exch_mgr_alloc() to ensure specified min_xid lower bits are zero since these bits are used to carry cpu info. Adds and initializes struct fc_exch_pool with all required fields to manage exches in pool. Allocates per cpu struct fc_exch_pool with memory for exches array for range of exches per pool. The exches array memory is followed by struct fc_exch_pool. Adds fc_exch_ptr_get/set() helper functions to get/set exch ptr in pool exches array at specified array index. Increases default FCOE_MAX_XID to 0x0FFF from 0x07EF, so that more exches are available per cpu after above described exch id range division across all cpus to each pool. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-09-05[SCSI] libfc: Fix misleading debug statementRobert Love1-1/+3
The statement reads, "Exchange timed out, notifying the upper layer", however, this statement is printed whenever the timer is armed. This is confusing to someone debugging the code because every time an exchange is initialized, there is an incorrect statement stating that the timer has already timed out. This patch changes the statement to read, "Exchange timer armed" which is more accurate. This patch also adds a debug statement in the timeout handler to properly indicate that the exchange has timed out. Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] fcoe, libfc: adds offload EM per eth device with only single xid range per EMVasu Dev1-76/+18
Updates fcoe_em_config to allocate a single instance of sharable offload EM for supported lp->lro_xid per eth device, and then share this EM for subsequently more lports creation on same eth device (e.g when using VLAN). Adds tiny fcoe_oem_match function for offload EM to return true for read types IO to have read IO exchanges allocated from offload shared EM. Removes fc_em_alloc_xid function completely which was needed to manage two xid ranges within a EM, this is not needed any more with allocation of separate sharable offload EM per eth device. Instead this patch adds simple xid allocation logic to manage single xid range. Adds fc_exch_em_alloc with mp->next_xid as cursor to allocate new xid from single xid range of EM, uses mp->next_xid instead removed mp->last_xid which slightly increase probability of finding empty xid on exch allocation. Removes restriction of not allowing use of xid zero along with changing two xid range change to single xid range. Makes fc_fcp_ddp_setup calling conditional to only xid allocated from shared offload EM. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] fcoe, fnic, libfc: modifies current code paths to use EM anchor listVasu Dev1-74/+117
Modifies current code to use EM anchor list in EM allocation, EM free, EM reset, exch allocation and exch lookup code paths. 1. Modifies fc_exch_mgr_alloc to accept EM match function and then have allocated EM added to the lport using fc_exch_mgr_add API while also updating EM kref for newly added EM. 2. Updates fc_exch_mgr_free API to accept only lport pointer instead EM and then have this API free all EMs of the lport from EM anchor list. 3. Removes single lport pointer link from the EM, which was used in associating lport pointer in newly allocated exchange. Instead have lport pointer passed along new exchange allocation call path and then store passed lport pointer in newly allocated exchange, this will allow a single EM instance to be used across more than one lport and used in EM reset to reset only lport specific exchanges. 4. Modifies fc_exch_mgr_reset to reset all EMs from the EM anchor list of the lport, adds additional exch lport pointer (ep->lp) check for shared EM case to reset exchange specific to a lport requested reset. 5. Updates exch allocation API fc_exch_alloc to use EM anchor list and its anchor match func pointer. The fc_exch_alloc will walk the list of EMs until it finds a match, a match will be either null match func pointer or call to match function returning true value. 6. Updates fc_exch_recv to accept incoming frame on local port using only lport pointer and frame pointer without specifying EM instance of incoming frame. Instead modified fc_exch_recv to locate EM for the incoming frame by matching xid of incoming frame against a EM xid range. This change was required to use EM list in libfc Rx path and after this change the lport fc_exch_mgr pointer emp is not needed anymore, so removed emp pointer. 7. Updates fnic for removed lport emp pointer and above modified libfc APIs fc_exch_recv, fc_exch_mgr_alloc and fc_exch_mgr_free. 8. Removes exch_get and exch_put from libfc_function_template as these are no longer needed with EM anchor list and its match function use. Also removes its default function fc_exch_get. A defect this patch introduced regarding the libfc initialization order in the fnic driver was fixed by Joe Eykholt <jeykholt@cisco.com>. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] libfc: Remove the FC_EM_DBG macroRobert Love1-7/+6
Currently there is a 1:1 relationship between the lport and exchange manager. This macro takes an EM as an argument and determines the lport from it. However, later patches will use an EM list per lport, so we will no longer have this 1:1 relationship- this macro must change. The FC_EM_DBG macro is rarely used. There are four callers, two can use FC_LPORT_DBG instead and two can be removed since they're not necessary. This patch makes those changes and removes the macro. Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] fcoe, libfc: adds exchange manager(EM) anchor list per lport and related APIsVasu Dev1-0/+48
Adds EM list using a anchor struct fc_exch_mgr_anchor, anchor is used to allow same EM instance sharing across more than one lport on a eth device, this implementation is per discussed design posted at http://www.open-fcoe.org/pipermail/devel/2009-June/002566.html. The shared EM is required for multiple lports on eth device when using multiple VLANs or NPIV. Adds fc_exch_mgr_add API to add a EM to the lport and fc_exch_mgr_del API to delete previously added EM. Also adds function fc_exch_mgr_destroy() to destroy allocated EM. The kref is added to the EM to keep track of EM usage count, the EM is destroyed when no longer in use upon kref reaching to zero. The caller can specify match function to fc_exch_mgr_add, this will be used in determining exchange allocation from its EM or not. Moved calling of fcoe_em_config below fcoe_libfc_config calling, so that list head lp->ema_list is initialized before configuring EM. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] libfc: fix WARNING from fc_seq_start_next on closed exchangesJoe Eykholt1-1/+0
We saw periodic messages like: WARNING: at drivers/scsi/libfc/fc_exch.c:825 fc_seq_start_next+0x30/0x4b This was due to trying to allocate a sequence in a request handler when the exchange had been reset. Delete the WARN_ON. Signed-off-by: Joe Eykholt <jeykholt@cisco.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22[SCSI] libfc: rename lport NONE state to DISABLEDJoe Eykholt1-1/+1
The state NONE was meant to be invalid, but has been used as the initial state. Rename it to be DISABLED, as more descriptive. Further patches will make it the like the RESET state, except it won't transition to FLOGI until fc_lport_fabric_login() is called. Signed-off-by: Joe Eykholt <jeykholt@cisco.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-07-30[SCSI] libfc: fix a circular locking warning during sending RRQVasu Dev1-8/+15
Currently the fc_exch_rrq is called with fc_exch's ex_lock held. The fc_exch_rrq allocates new exch and that requires taking ex_lock again after EM lock. This locking order causes warning, see more details on this warning at :- http://www.open-fcoe.org/pipermail/devel/2009-July/003251.html This patch fixes this by dropping the ex_lock before calling fc_exch_rrq(). The fc_exch_rrq needs to grab ex_lock lock again to schedule RRQ retry and in the meanwhile fc_exch_reset could occur before ex_lock is grabbed inside fc_exch_rrq. So to handle this case, this patch adds additional check to detect fc_exch_reset after ex_lock acquired and in case the fc_exch_reset occurred then abandons the RRQ retry and releases the exch. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-21libfc: Add runtime debugging with debug_logging module parameterRobert Love1-33/+25
This patch adds the /sys/module/libfc/parameters/debug_logging file to sysfs as a module parameter. It accepts an integer bitmask for logging. Currently it supports: bit LSB 0 = general libfc debugging 1 = lport debugging 2 = disc debugging 3 = rport debugging 4 = fcp debugging 5 = EM debugging 6 = exch/seq debugging 7 = scsi logging (mostly error handling) the other bits are not used at this time. The patch converts all of the libfc source files to use these new macros and removes the old FC_DBG macro. Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-08[SCSI] libfc: Check if exchange is completed when receiving a sequenceSteve Ma1-0/+4
When a sequence is received in response to an exchange we issued previously, we should check to see if the exchange has completed. If yes, the sequence should be discarded. Since the exchange might be still in the completion process, it should be untouched. Signed-off-by: Steve Ma <steve.ma@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-13[SCSI] libfc: add support of large receive offload by ddp in fc_fcpYi Zou1-1/+3
When LLD supports direct data placement (ddp) for large receive of an scsi i/o coming into fc_fcp, we call into libfc_function_template's ddp_setup() to prepare for a ddp of large receive for this read I/O. When I/O is complete, we call the corresponding ddp_done() to get the length of data ddped as well as to let LLD do clean up. fc_fcp_ddp_setup()/fc_fcp_ddp_done() are added to setup and complete a ddped read I/O described by the given fc_fcp_pkt. They would call into corresponding ddp_setup/ddp_done implemented by the fcoe layer. Eventually, fcoe layer calls into LLD's ddp_setup/ddp_done provided through net_device Signed-off-by: Yi Zou <yi.zou@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-12[SCSI] libfc: Correct use of ! and &Julia Lawall1-1/+1
!ep->esb_stat is either 1 or 0, and the rightmost bit of ESB_ST_COMPLETE is always 0, making the result of !ep->esb_stat & ESB_ST_COMPLETE always 0. Thus parentheses around the argument to ! seem needed. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ expression E; constant C; @@ ( !E & !C | - !E & C + !(E & C) ) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-10[SCSI] libfc: do not change the fh_rx_id of a recevied frameYi Zou1-13/+0
We shouldn't be altering inbound frames. Signed-off-by: Yi Zou <yi.zou@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-10[SCSI] libfc, fcoe: Cleanup function formatting and minor typosRobert Love1-5/+5
1) There were a few functions with a strange layout, i.e. all arguments on the second line, when not necessary. Where ever possible I moved the return value to the same line as the function name. However, when the line was too long to have a single argument on the same line I moved the return value to above line. For example: <short return> <function name>(<arg 1>, <arg2>) and <very long return value> <function name>(<arg1>, <arg2>) 2) Removed one extra whitespace line 3) Fixed two typos Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06[SCSI] libfc: rport retry on LS_RJT from certain ELSChris Leech1-2/+0
This allows any rport ELS to retry on LS_RJT. The rport error handling would only retry on resource allocation failures and exchange timeouts. I have a target that will occasionally reject PLOGI when we do a quick LOGO/PLOGI. When a critical ELS was rejected, libfc would fail silently leaving the rport in a dead state. The retry count and delay are managed by fc_rport_error_retry. If the retry count is exceeded fc_rport_error will be called. When retrying is not the correct course of action, fc_rport_error can be called directly. Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06[SCSI] libfc: fixed a soft lockup issue in fc_exch_recv_abtsVasu Dev1-1/+1
The fc_seq_start_next grabs ep->ex_lock but this lock was already held here, so instead called fc_seq_start_next_locked to avoid soft lockup. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06[SCSI] libfc: handle RRQ exch timeoutVasu Dev1-1/+1
Cleanup exchange held due to RRQ when RRQ exch times out, in this case the ABTS is already done causing RRQ req therefore proceeding with cleanup in fc_exch_rrq_resp should be okay to restore exch resource. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06[SCSI] libfc: Pass lport in exch_mgr_resetAbhijeet Joglekar1-1/+2
fc_exch_mgr structure is private to fc_exch.c. To export exch_mgr_reset to transport, transport needs access to the exch manager. Change exch_mgr_reset to use lport param which is the shared structure between libFC and transport. Alternatively, fc_exch_mgr definition can be moved to libfc.h so that lport can be accessed from mp*. Signed-off-by: Abhijeet Joglekar <abjoglek@cisco.com> Signed-off-by: Robert Love <robert.w.love@intel.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-29[SCSI] libfc: A modular Fibre Channel libraryRobert Love1-0/+1970
libFC is composed of 4 blocks supported by an exchange manager and a framing library. The upper 4 layers are fc_lport, fc_disc, fc_rport and fc_fcp. A LLD that uses libfc could choose to either use libfc's block, or using the transport template defined in libfc.h, override one or more blocks with its own implementation. The EM (Exchange Manager) manages exhcanges/sequences for all commands- ELS, CT and FCP. The framing library frames ELS and CT commands. The fc_lport block manages the library's representation of the host's FC enabled ports. The fc_disc block manages discovery of targets as well as handling changes that occur in the FC fabric (via. RSCN events). The fc_rport block manages the library's representation of other entities in the FC fabric. Currently the library uses this block for targets, its peer when in point-to-point mode and the directory server, but can be extended for other entities if needed. The fc_fcp block interacts with the scsi-ml and handles all I/O. Signed-off-by: Robert Love <robert.w.love@intel.com> [jejb: added include of delay.h to fix ppc64 compile prob spotted by sfr] Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>