kernel/drivers/scsi/lpfc/lpfc_debugfs.c, branch linux-5.1.y

scsi: lpfc: change snprintf to scnprintf for possible overflow

2019-05-11T05:49:55Z

commit e7f7b6f38a44697428f5a2e7c606de028df2b0e3 upstream. Change snprintf to scnprintf. There are generally two cases where using snprintf causes problems. 1) Uses of size += snprintf(buf, SIZE - size, fmt, ...) In this case, if snprintf would have written more characters than what the buffer size (SIZE) is, then size will end up larger than SIZE. In later uses of snprintf, SIZE - size will result in a negative number, leading to problems. Note that size might already be too large by using size = snprintf before the code reaches a case of size += snprintf. 2) If size is ultimately used as a length parameter for a copy back to user space, then it will potentially allow for a buffer overflow and information disclosure when size is greater than SIZE. When the size is used to index the buffer directly, we can have memory corruption. This also means when size = snprintf... is used, it may also cause problems since size may become large. Copying to userspace is mitigated by the HARDENED_USERCOPY kernel configuration. The solution to these issues is to use scnprintf which returns the number of characters actually written to the buffer, so the size variable will never exceed SIZE. Signed-off-by: Silvio Cesare Signed-off-by: Willy Tarreau Signed-off-by: James Smart Cc: Dick Kennedy Cc: Dan Carpenter Cc: Kees Cook Cc: Will Deacon Cc: Greg KH Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: lpfc: fix a handful of indentation issues

2019-02-14T03:15:42Z

There are a handful of statements that are indented incorrectly. Fix these. Signed-off-by: Colin Ian King Acked-by: James Smart Signed-off-by: Martin K. Petersen

scsi: lpfc: Update 12.2.0.0 file copyrights to 2019

2019-02-06T03:29:50Z

For files modified as part of 12.2.0.0 patches, update copyright to 2019 Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Fix default driver parameter collision for allowing NPIV support

2019-02-06T03:29:50Z

The conversion to enable SCSI and NVME fc4 support ran into an issue with NPIV support. With NVME, NPIV is not currently supported, but with SCSI it was. The driver reverted to its lowest setting meaning NPIV with SCSI was not allowed. Convert the NPIV checks and implementation so that SCSI can continue to allow NPIV support. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Rework EQ/CQ processing to address interrupt coalescing

2019-02-06T03:29:49Z

When driving high iop counts, auto_imax coalescing kicks in and drives the performance to extremely small iops levels. There are two issues: 1) auto_imax is enabled by default. The auto algorithm, when iops gets high, divides the iops by the hdwq count and uses that value to calculate EQ_Delay. The EQ_Delay is set uniformly on all EQs whether they have load or not. The EQ_delay is only manipulated every 5s (a long time). Thus there were large 5s swings of no interrupt delay followed by large/maximum delay, before repeating. 2) When processing a CQ, the driver got mixed up on the rate of when to ring the doorbell to keep the chip appraised of the eqe or cqe consumption as well as how how long to sit in the thread and process queue entries. Currently, the driver capped its work at 64 entries (very small) and exited/rearmed the CQ. Thus, on heavy loads, additional overheads were taken to exit and re-enter the interrupt handler. Worse, if in the large/maximum coalescing windows,k it could be a while before getting back to servicing. The issues are corrected by the following: - A change in defaults. Auto_imax is turned OFF and fcp_imax is set to 0. Thus all interrupts are immediate. - Cleanup of field names and their meanings. Existing names were non-intuitive or used for duplicate things. - Added max_proc_limit field, to control the length of time the handlers would service completions. - Reworked EQ handling: Added common routine that walks eq, applying notify interval and max processing limits. Use queue_claimed to claim ownership of the queue while processing. Always rearm the queue whenever the common routine is called. Rework queue element processing, namely to eliminate hba_index vs host_index. Only one index is necessary. The queue entry can be marked invalid and the host_index updated immediately after eqe processing. After rework, xx_release routines are now DB write functions. Renamed the routines as such. Moved lpfc_sli4_eq_flush(), which does similar action, to same area. Replaced the 2 individual loops that walk an eq with a call to the common routine. Slightly revised lpfc_sli4_hba_handle_eqe() calling syntax. Added per-cpu counters to detect interrupt rates and scale interrupt coalescing values. - Reworked CQ handling: Added common routine that walks cq, applying notify interval and max processing limits. Use queue_claimed to claim ownership of the queue while processing. Always rearm the queue whenever the common routine is called. Rework queue element processing, namely to eliminate hba_index vs host_index. Only one index is necessary. The queue entry can be marked invalid and the host_index updated immediately after cqe processing. After rework, xx_release routines are now DB write functions. Renamed the routines as such. Replaced the 3 individual loops that walk a cq with a call to the common routine. Redefined lpfc_sli4_sp_handle_mcqe() to commong handler definition with queue reference. Add increment for mbox completion to handler. - Added a new module/sysfs attribute: lpfc_cq_max_proc_limit To allow dynamic changing of the CQ max_proc_limit value being used. Although this leaves an EQ as an immediate interrupt, that interrupt will only occur if a CQ bound to it is in an armed state and has cqe's to process. By staying in the cq processing routine longer, high loads will avoid generating more interrupts as they will only rearm as the processing thread exits. The immediately interrupt is also beneficial to idle or lower-processing CQ's as they get serviced immediately without being penalized by sharing an EQ with a more loaded CQ. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Support non-uniform allocation of MSIX vectors to hardware queues

2019-02-06T03:29:49Z

So far MSIX vector allocation assumed it would be 1:1 with hardware queues. However, there are several reasons why fewer MSIX vectors may be allocated than hardware queues such as the platform being out of vectors or adapter limits being less than cpu count. This patch reworks the MSIX/EQ relationships with the per-cpu hardware queues so they can function independently. MSIX vectors will be equitably split been cpu sockets/cores and then the per-cpu hardware queues will be mapped to the vectors most efficient for them. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Adapt partitioned XRI lists to efficient sharing

2019-02-06T03:29:09Z

The XRI get/put lists were partitioned per hardware queue. However, the adapter rarely had sufficient resources to give a large number of resources per queue. As such, it became common for a cpu to encounter a lack of XRI resource and request the upper io stack to retry after returning a BUSY condition. This occurred even though other cpus were idle and not using their resources. Create as efficient a scheme as possible to move resources to the cpus that need them. Each cpu maintains a small private pool which it allocates from for io. There is a watermark that the cpu attempts to keep in the private pool. The private pool, when empty, pulls from a global pool from the cpu. When the cpu's global pool is empty it will pull from other cpu's global pool. As there many cpu global pools (1 per cpu or hardware queue count) and as each cpu selects what cpu to pull from at different rates and at different times, it creates a radomizing effect that minimizes the number of cpu's that will contend with each other when the steal XRI's from another cpu's global pool. On io completion, a cpu will push the XRI back on to its private pool. A watermark level is maintained for the private pool such that when it is exceeded it will move XRI's to the CPU global pool so that other cpu's may allocate them. On NVME, as heartbeat commands are critical to get placed on the wire, a single expedite pool is maintained. When a heartbeat is to be sent, it will allocate an XRI from the expedite pool rather than the normal cpu private/global pools. On any io completion, if a reduction in the expedite pools is seen, it will be replenished before the XRI is placed on the cpu private pool. Statistics are added to aid understanding the XRI levels on each cpu and their behaviors. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Move SCSI and NVME Stats to hardware queue structures

2019-02-06T03:29:08Z

Many io statistics were being sampled and saved using adapter-based data structures. This was creating a lot of contention and cache thrashing in the I/O path. Move the statistics to the hardware queue data structures. Given the per-queue data structures, use of atomic types is lessened. Add new sysfs and debugfs stat routines to collate the per hardware queue values and report at an adapter level. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Adapt cpucheck debugfs logic to Hardware Queues

2019-02-06T03:28:11Z

Similar to the io execution path that reports cpu context information, the debugfs routines for cpu information needs to be aligned with new hardware queue implementation. Convert debugfs cnd nvme cpucheck statistics to report information per Hardware Queue. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: lpfc: Partition XRI buffer list across Hardware Queues

2019-02-06T03:24:22Z

Once the IO buff allocations were made shared, there was a single XRI buffer list shared by all hardware queues. A single list isn't great for performance when shared across the per-cpu hardware queues. Create a separate XRI IO buffer get/put list for each Hardware Queue. As SGLs and associated IO buffers get allocated/posted to the firmware; round robin their assignment across all available hardware Queues so that there is an equitable assignment. Modify SCSI and NVME IO submit code paths to use the Hardware Queue logic for XRI allocation. Add a debugfs interface to display hardware queue statistics Added new empty_io_bufs counter to track if a cpu runs out of XRIs. Replace common_ variables/names with io_ to make meanings clearer. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen