Commit 93204b78 authored by Chaitra P B's avatar Chaitra P B Committed by Martin K. Petersen
Browse files

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: default avatarChaitra P B <chaitra.basappa@broadcom.com>
Signed-off-by: default avatarSuganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent cd33223b

drivers/scsi/mpt3sas/mpt3sas_base.c

+59 −52
Original line number Diff line number Diff line
@@ -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;

	u16 index, j;

	struct chain_tracker *ct;



	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;

	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)

		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,

				    ioc->chain_lookup[i].chain_buffer,

				    ioc->chain_lookup[i].chain_buffer_dma);

						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 */

drivers/scsi/mpt3sas/mpt3sas_base.h

+6 −2
Original line number Diff line number Diff line
@@ -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;

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