From: Chaitra P B Date: Tue, 24 Apr 2018 09:28:32 +0000 (-0400) Subject: scsi: mpt3sas: Lockless access for chain buffers. X-Git-Tag: v4.18-rc1~66^2~162 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=93204b782a88f2067ff83cb732b66236644c4c56;p=linux.git scsi: mpt3sas: Lockless access for chain buffers. Introduces Chain lookup table/tracker and implements accessing chain buffer using smid. Removed link list based access of chain buffer which requires lock and allocated as many chains needed. Signed-off-by: Chaitra P B Signed-off-by: Suganath Prabu S Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 7a7e32425293..147524cce8d7 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -297,12 +297,15 @@ static void * _base_get_chain_buffer_dma_to_chain_buffer(struct MPT3SAS_ADAPTER *ioc, dma_addr_t chain_buffer_dma) { - u16 index; - - for (index = 0; index < ioc->chain_depth; index++) { - if (ioc->chain_lookup[index].chain_buffer_dma == - chain_buffer_dma) - return ioc->chain_lookup[index].chain_buffer; + u16 index, j; + struct chain_tracker *ct; + + for (index = 0; index < ioc->scsiio_depth; index++) { + for (j = 0; j < ioc->chains_needed_per_io; j++) { + ct = &ioc->chain_lookup[index].chains_per_smid[j]; + if (ct && ct->chain_buffer_dma == chain_buffer_dma) + return ct->chain_buffer; + } } pr_info(MPT3SAS_FMT "Provided chain_buffer_dma address is not in the lookup list\n", @@ -1679,7 +1682,8 @@ _base_add_sg_single_64(void *paddr, u32 flags_length, dma_addr_t dma_addr) * @ioc: per adapter object * @scmd: SCSI commands of the IO request * - * Returns chain tracker(from ioc->free_chain_list) + * Returns chain tracker from chain_lookup table using key as + * smid and smid's chain_offset. */ static struct chain_tracker * _base_get_chain_buffer_tracker(struct MPT3SAS_ADAPTER *ioc, @@ -1687,20 +1691,15 @@ _base_get_chain_buffer_tracker(struct MPT3SAS_ADAPTER *ioc, { struct chain_tracker *chain_req; struct scsiio_tracker *st = scsi_cmd_priv(scmd); - unsigned long flags; + u16 smid = st->smid; + u8 chain_offset = + atomic_read(&ioc->chain_lookup[smid - 1].chain_offset); - spin_lock_irqsave(&ioc->scsi_lookup_lock, flags); - if (list_empty(&ioc->free_chain_list)) { - spin_unlock_irqrestore(&ioc->scsi_lookup_lock, flags); - dfailprintk(ioc, pr_warn(MPT3SAS_FMT - "chain buffers not available\n", ioc->name)); + if (chain_offset == ioc->chains_needed_per_io) return NULL; - } - chain_req = list_entry(ioc->free_chain_list.next, - struct chain_tracker, tracker_list); - list_del_init(&chain_req->tracker_list); - list_add_tail(&chain_req->tracker_list, &st->chain_list); - spin_unlock_irqrestore(&ioc->scsi_lookup_lock, flags); + + chain_req = &ioc->chain_lookup[smid - 1].chains_per_smid[chain_offset]; + atomic_inc(&ioc->chain_lookup[smid - 1].chain_offset); return chain_req; } @@ -3281,13 +3280,7 @@ void mpt3sas_base_clear_st(struct MPT3SAS_ADAPTER *ioc, return; st->cb_idx = 0xFF; st->direct_io = 0; - if (!list_empty(&st->chain_list)) { - unsigned long flags; - - spin_lock_irqsave(&ioc->scsi_lookup_lock, flags); - list_splice_init(&st->chain_list, &ioc->free_chain_list); - spin_unlock_irqrestore(&ioc->scsi_lookup_lock, flags); - } + atomic_set(&ioc->chain_lookup[st->smid - 1].chain_offset, 0); } /** @@ -4105,6 +4098,8 @@ static void _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc) { int i = 0; + int j = 0; + struct chain_tracker *ct; struct reply_post_struct *rps; dexitprintk(ioc, pr_info(MPT3SAS_FMT "%s\n", ioc->name, @@ -4195,14 +4190,18 @@ _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc) kfree(ioc->hpr_lookup); kfree(ioc->internal_lookup); if (ioc->chain_lookup) { - for (i = 0; i < ioc->chain_depth; i++) { - if (ioc->chain_lookup[i].chain_buffer) - dma_pool_free(ioc->chain_dma_pool, - ioc->chain_lookup[i].chain_buffer, - ioc->chain_lookup[i].chain_buffer_dma); + for (i = 0; i < ioc->scsiio_depth; i++) { + for (j = 0; j < ioc->chains_needed_per_io; j++) { + ct = &ioc->chain_lookup[i].chains_per_smid[j]; + if (ct && ct->chain_buffer) + dma_pool_free(ioc->chain_dma_pool, + ct->chain_buffer, + ct->chain_buffer_dma); + } + kfree(ioc->chain_lookup[i].chains_per_smid); } dma_pool_destroy(ioc->chain_dma_pool); - free_pages((ulong)ioc->chain_lookup, ioc->chain_pages); + kfree(ioc->chain_lookup); ioc->chain_lookup = NULL; } } @@ -4224,7 +4223,8 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc) u16 max_request_credit, nvme_blocks_needed; unsigned short sg_tablesize; u16 sge_size; - int i; + int i, j; + struct chain_tracker *ct; dinitprintk(ioc, pr_info(MPT3SAS_FMT "%s\n", ioc->name, __func__)); @@ -4505,15 +4505,24 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc) ioc->name, ioc->request, ioc->scsiio_depth)); ioc->chain_depth = min_t(u32, ioc->chain_depth, MAX_CHAIN_DEPTH); - sz = ioc->chain_depth * sizeof(struct chain_tracker); - ioc->chain_pages = get_order(sz); - ioc->chain_lookup = (struct chain_tracker *)__get_free_pages( - GFP_KERNEL, ioc->chain_pages); + sz = ioc->scsiio_depth * sizeof(struct chain_lookup); + ioc->chain_lookup = kzalloc(sz, GFP_KERNEL); if (!ioc->chain_lookup) { - pr_err(MPT3SAS_FMT "chain_lookup: __get_free_pages failed\n", - ioc->name); + pr_err(MPT3SAS_FMT "chain_lookup: __get_free_pages " + "failed\n", ioc->name); goto out; } + + sz = ioc->chains_needed_per_io * sizeof(struct chain_tracker); + for (i = 0; i < ioc->scsiio_depth; i++) { + ioc->chain_lookup[i].chains_per_smid = kzalloc(sz, GFP_KERNEL); + if (!ioc->chain_lookup[i].chains_per_smid) { + pr_err(MPT3SAS_FMT "chain_lookup: " + " kzalloc failed\n", ioc->name); + goto out; + } + } + ioc->chain_dma_pool = dma_pool_create("chain pool", &ioc->pdev->dev, ioc->chain_segment_sz, 16, 0); if (!ioc->chain_dma_pool) { @@ -4521,17 +4530,21 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc) ioc->name); goto out; } - for (i = 0; i < ioc->chain_depth; i++) { - ioc->chain_lookup[i].chain_buffer = dma_pool_alloc( + for (i = 0; i < ioc->scsiio_depth; i++) { + for (j = 0; j < ioc->chains_needed_per_io; j++) { + ct = &ioc->chain_lookup[i].chains_per_smid[j]; + ct->chain_buffer = dma_pool_alloc( ioc->chain_dma_pool , GFP_KERNEL, - &ioc->chain_lookup[i].chain_buffer_dma); - if (!ioc->chain_lookup[i].chain_buffer) { - ioc->chain_depth = i; - goto chain_done; + &ct->chain_buffer_dma); + if (!ct->chain_buffer) { + pr_err(MPT3SAS_FMT "chain_lookup: " + " pci_pool_alloc failed\n", ioc->name); + goto out; + } } total_sz += ioc->chain_segment_sz; } - chain_done: + dinitprintk(ioc, pr_info(MPT3SAS_FMT "chain pool depth(%d), frame_size(%d), pool_size(%d kB)\n", ioc->name, ioc->chain_depth, ioc->chain_segment_sz, @@ -6179,12 +6192,6 @@ _base_make_ioc_operational(struct MPT3SAS_ADAPTER *ioc) &ioc->internal_free_list); } - /* chain pool */ - INIT_LIST_HEAD(&ioc->free_chain_list); - for (i = 0; i < ioc->chain_depth; i++) - list_add_tail(&ioc->chain_lookup[i].tracker_list, - &ioc->free_chain_list); - spin_unlock_irqrestore(&ioc->scsi_lookup_lock, flags); /* initialize Reply Free Queue */ diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h index d31a1912d31b..eeeb3b711144 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.h +++ b/drivers/scsi/mpt3sas/mpt3sas_base.h @@ -770,7 +770,11 @@ struct pcie_sg_list { struct chain_tracker { void *chain_buffer; dma_addr_t chain_buffer_dma; - struct list_head tracker_list; +}; + +struct chain_lookup { + struct chain_tracker *chains_per_smid; + atomic_t chain_offset; }; /** @@ -1261,7 +1265,7 @@ struct MPT3SAS_ADAPTER { u32 page_size; /* chain */ - struct chain_tracker *chain_lookup; + struct chain_lookup *chain_lookup; struct list_head free_chain_list; struct dma_pool *chain_dma_pool; ulong chain_pages;