From a3db102def237c27c6f2a2a6a58b79b2f2d4e39f Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 17 Aug 2017 13:13:35 -0700 Subject: [PATCH] skd: Reduce memory usage Every single coherent DMA memory buffer occupies at least one page. Reduce memory usage by switching from coherent buffers to streaming DMA for I/O requests (struct skd_fitmsg_context) and S/G-lists (struct fit_sg_descriptor[]). Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/block/skd_main.c | 145 +++++++++++++++++++++++++++++---------- 1 file changed, 108 insertions(+), 37 deletions(-) diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c index a20434ca3e18..610c8979dc7e 100644 --- a/drivers/block/skd_main.c +++ b/drivers/block/skd_main.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -256,6 +257,9 @@ struct skd_device { u8 skcomp_cycle; u32 skcomp_ix; + struct kmem_cache *msgbuf_cache; + struct kmem_cache *sglist_cache; + struct kmem_cache *databuf_cache; struct fit_completion_entry_v1 *skcomp_table; struct fit_comp_error_info *skerr_table; dma_addr_t cq_dma_address; @@ -538,6 +542,11 @@ static void skd_process_request(struct request *req, bool last) return; } + dma_sync_single_for_device(&skdev->pdev->dev, skreq->sksg_dma_address, + skreq->n_sg * + sizeof(struct fit_sg_descriptor), + DMA_TO_DEVICE); + spin_lock_irqsave(&skdev->lock, flags); /* Either a FIT msg is in progress or we have to start one. */ skmsg = skdev->skmsg; @@ -1078,6 +1087,11 @@ static void skd_complete_internal(struct skd_device *skdev, dev_dbg(&skdev->pdev->dev, "complete internal %x\n", scsi->cdb[0]); + dma_sync_single_for_cpu(&skdev->pdev->dev, + skspcl->db_dma_address, + skspcl->req.sksg_list[0].byte_count, + DMA_BIDIRECTIONAL); + skspcl->req.completion = *skcomp; skspcl->req.state = SKD_REQ_STATE_IDLE; skspcl->req.id += SKD_ID_INCR; @@ -1263,6 +1277,9 @@ static void skd_send_fitmsg(struct skd_device *skdev, */ qcmd |= FIT_QCMD_MSGSIZE_64; + dma_sync_single_for_device(&skdev->pdev->dev, skmsg->mb_dma_address, + skmsg->length, DMA_TO_DEVICE); + /* Make sure skd_msg_buf is written before the doorbell is triggered. */ smp_wmb(); @@ -1274,6 +1291,8 @@ static void skd_send_special_fitmsg(struct skd_device *skdev, { u64 qcmd; + WARN_ON_ONCE(skspcl->req.n_sg != 1); + if (unlikely(skdev->dbg_level > 1)) { u8 *bp = (u8 *)skspcl->msg_buf; int i; @@ -1307,6 +1326,17 @@ static void skd_send_special_fitmsg(struct skd_device *skdev, qcmd = skspcl->mb_dma_address; qcmd |= FIT_QCMD_QID_NORMAL + FIT_QCMD_MSGSIZE_128; + dma_sync_single_for_device(&skdev->pdev->dev, skspcl->mb_dma_address, + SKD_N_SPECIAL_FITMSG_BYTES, DMA_TO_DEVICE); + dma_sync_single_for_device(&skdev->pdev->dev, + skspcl->req.sksg_dma_address, + 1 * sizeof(struct fit_sg_descriptor), + DMA_TO_DEVICE); + dma_sync_single_for_device(&skdev->pdev->dev, + skspcl->db_dma_address, + skspcl->req.sksg_list[0].byte_count, + DMA_BIDIRECTIONAL); + /* Make sure skd_msg_buf is written before the doorbell is triggered. */ smp_wmb(); @@ -2619,6 +2649,35 @@ static void skd_release_irq(struct skd_device *skdev) ***************************************************************************** */ +static void *skd_alloc_dma(struct skd_device *skdev, struct kmem_cache *s, + dma_addr_t *dma_handle, gfp_t gfp, + enum dma_data_direction dir) +{ + struct device *dev = &skdev->pdev->dev; + void *buf; + + buf = kmem_cache_alloc(s, gfp); + if (!buf) + return NULL; + *dma_handle = dma_map_single(dev, buf, s->size, dir); + if (dma_mapping_error(dev, *dma_handle)) { + kfree(buf); + buf = NULL; + } + return buf; +} + +static void skd_free_dma(struct skd_device *skdev, struct kmem_cache *s, + void *vaddr, dma_addr_t dma_handle, + enum dma_data_direction dir) +{ + if (!vaddr) + return; + + dma_unmap_single(&skdev->pdev->dev, dma_handle, s->size, dir); + kmem_cache_free(s, vaddr); +} + static int skd_cons_skcomp(struct skd_device *skdev) { int rc = 0; @@ -2695,18 +2754,14 @@ static struct fit_sg_descriptor *skd_cons_sg_list(struct skd_device *skdev, dma_addr_t *ret_dma_addr) { struct fit_sg_descriptor *sg_list; - u32 nbytes; - nbytes = sizeof(*sg_list) * n_sg; - - sg_list = pci_alloc_consistent(skdev->pdev, nbytes, ret_dma_addr); + sg_list = skd_alloc_dma(skdev, skdev->sglist_cache, ret_dma_addr, + GFP_DMA | __GFP_ZERO, DMA_TO_DEVICE); if (sg_list != NULL) { uint64_t dma_address = *ret_dma_addr; u32 i; - memset(sg_list, 0, nbytes); - for (i = 0; i < n_sg - 1; i++) { uint64_t ndp_off; ndp_off = (i + 1) * sizeof(struct fit_sg_descriptor); @@ -2720,15 +2775,14 @@ static struct fit_sg_descriptor *skd_cons_sg_list(struct skd_device *skdev, } static void skd_free_sg_list(struct skd_device *skdev, - struct fit_sg_descriptor *sg_list, u32 n_sg, + struct fit_sg_descriptor *sg_list, dma_addr_t dma_addr) { - u32 nbytes = sizeof(*sg_list) * n_sg; - if (WARN_ON_ONCE(!sg_list)) return; - pci_free_consistent(skdev->pdev, nbytes, sg_list, dma_addr); + skd_free_dma(skdev, skdev->sglist_cache, sg_list, dma_addr, + DMA_TO_DEVICE); } static int skd_init_request(struct blk_mq_tag_set *set, struct request *rq, @@ -2752,34 +2806,31 @@ static void skd_exit_request(struct blk_mq_tag_set *set, struct request *rq, struct skd_device *skdev = set->driver_data; struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq); - skd_free_sg_list(skdev, skreq->sksg_list, - skdev->sgs_per_request, - skreq->sksg_dma_address); + skd_free_sg_list(skdev, skreq->sksg_list, skreq->sksg_dma_address); } static int skd_cons_sksb(struct skd_device *skdev) { int rc = 0; struct skd_special_context *skspcl; - u32 nbytes; skspcl = &skdev->internal_skspcl; skspcl->req.id = 0 + SKD_ID_INTERNAL; skspcl->req.state = SKD_REQ_STATE_IDLE; - nbytes = SKD_N_INTERNAL_BYTES; - - skspcl->data_buf = pci_zalloc_consistent(skdev->pdev, nbytes, - &skspcl->db_dma_address); + skspcl->data_buf = skd_alloc_dma(skdev, skdev->databuf_cache, + &skspcl->db_dma_address, + GFP_DMA | __GFP_ZERO, + DMA_BIDIRECTIONAL); if (skspcl->data_buf == NULL) { rc = -ENOMEM; goto err_out; } - nbytes = SKD_N_SPECIAL_FITMSG_BYTES; - skspcl->msg_buf = pci_zalloc_consistent(skdev->pdev, nbytes, - &skspcl->mb_dma_address); + skspcl->msg_buf = skd_alloc_dma(skdev, skdev->msgbuf_cache, + &skspcl->mb_dma_address, + GFP_DMA | __GFP_ZERO, DMA_TO_DEVICE); if (skspcl->msg_buf == NULL) { rc = -ENOMEM; goto err_out; @@ -2886,6 +2937,7 @@ static struct skd_device *skd_construct(struct pci_dev *pdev) { struct skd_device *skdev; int blk_major = skd_major; + size_t size; int rc; skdev = kzalloc(sizeof(*skdev), GFP_KERNEL); @@ -2914,6 +2966,31 @@ static struct skd_device *skd_construct(struct pci_dev *pdev) INIT_WORK(&skdev->start_queue, skd_start_queue); INIT_WORK(&skdev->completion_worker, skd_completion_worker); + size = max(SKD_N_FITMSG_BYTES, SKD_N_SPECIAL_FITMSG_BYTES); + skdev->msgbuf_cache = kmem_cache_create("skd-msgbuf", size, 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!skdev->msgbuf_cache) + goto err_out; + WARN_ONCE(kmem_cache_size(skdev->msgbuf_cache) < size, + "skd-msgbuf: %d < %zd\n", + kmem_cache_size(skdev->msgbuf_cache), size); + size = skd_sgs_per_request * sizeof(struct fit_sg_descriptor); + skdev->sglist_cache = kmem_cache_create("skd-sglist", size, 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!skdev->sglist_cache) + goto err_out; + WARN_ONCE(kmem_cache_size(skdev->sglist_cache) < size, + "skd-sglist: %d < %zd\n", + kmem_cache_size(skdev->sglist_cache), size); + size = SKD_N_INTERNAL_BYTES; + skdev->databuf_cache = kmem_cache_create("skd-databuf", size, 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!skdev->databuf_cache) + goto err_out; + WARN_ONCE(kmem_cache_size(skdev->databuf_cache) < size, + "skd-databuf: %d < %zd\n", + kmem_cache_size(skdev->databuf_cache), size); + dev_dbg(&skdev->pdev->dev, "skcomp\n"); rc = skd_cons_skcomp(skdev); if (rc < 0) @@ -2986,31 +3063,21 @@ static void skd_free_skmsg(struct skd_device *skdev) static void skd_free_sksb(struct skd_device *skdev) { - struct skd_special_context *skspcl; - u32 nbytes; - - skspcl = &skdev->internal_skspcl; - - if (skspcl->data_buf != NULL) { - nbytes = SKD_N_INTERNAL_BYTES; + struct skd_special_context *skspcl = &skdev->internal_skspcl; - pci_free_consistent(skdev->pdev, nbytes, - skspcl->data_buf, skspcl->db_dma_address); - } + skd_free_dma(skdev, skdev->databuf_cache, skspcl->data_buf, + skspcl->db_dma_address, DMA_BIDIRECTIONAL); skspcl->data_buf = NULL; skspcl->db_dma_address = 0; - if (skspcl->msg_buf != NULL) { - nbytes = SKD_N_SPECIAL_FITMSG_BYTES; - pci_free_consistent(skdev->pdev, nbytes, - skspcl->msg_buf, skspcl->mb_dma_address); - } + skd_free_dma(skdev, skdev->msgbuf_cache, skspcl->msg_buf, + skspcl->mb_dma_address, DMA_TO_DEVICE); skspcl->msg_buf = NULL; skspcl->mb_dma_address = 0; - skd_free_sg_list(skdev, skspcl->req.sksg_list, 1, + skd_free_sg_list(skdev, skspcl->req.sksg_list, skspcl->req.sksg_dma_address); skspcl->req.sksg_list = NULL; @@ -3056,6 +3123,10 @@ static void skd_destruct(struct skd_device *skdev) dev_dbg(&skdev->pdev->dev, "skcomp\n"); skd_free_skcomp(skdev); + kmem_cache_destroy(skdev->databuf_cache); + kmem_cache_destroy(skdev->sglist_cache); + kmem_cache_destroy(skdev->msgbuf_cache); + dev_dbg(&skdev->pdev->dev, "skdev\n"); kfree(skdev); } -- 2.20.1