scsi: qla2xxx: Fix DMA error when the DIF sg buffer crosses 4GB boundary

When SGE buffer containing DIF information crosses 4G boundary, it results
in DMA error. This patch fixes this issue by calculating SGE buffer size
and if it crosses 4G boundary, driver will split it into multiple SGE
buffers to avoid DMA error.

Signed-off-by: Giridhar Malavali <gmalavali@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 167 insertions, 2 deletions

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 3a4f68f40057..715b5526fb0a 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -299,6 +299,13 @@ MODULE_PARM_DESC(ql2xprotguard, "Override choice of DIX checksum\n"
 		 "  1 -- Force T10 CRC\n"
 		 "  2 -- Force IP checksum\n");
 
+int ql2xdifbundlinginternalbuffers;
+module_param(ql2xdifbundlinginternalbuffers, int, 0644);
+MODULE_PARM_DESC(ql2xdifbundlinginternalbuffers,
+    "Force using internal buffers for DIF information\n"
+    "0 (Default). Based on check.\n"
+    "1 Force using internal buffers\n");
+
 /*
  * SCSI host template entry points
  */
@@ -818,7 +825,44 @@ qla2xxx_qpair_sp_free_dma(void *ptr)
 		ha->gbl_dsd_inuse -= ctx1->dsd_use_cnt;
 		ha->gbl_dsd_avail += ctx1->dsd_use_cnt;
 		mempool_free(ctx1, ha->ctx_mempool);
+		sp->flags &= ~SRB_FCP_CMND_DMA_VALID;
+	}
+	if (sp->flags & SRB_DIF_BUNDL_DMA_VALID) {
+		struct crc_context *difctx = sp->u.scmd.ctx;
+		struct dsd_dma *dif_dsd, *nxt_dsd;
+
+		list_for_each_entry_safe(dif_dsd, nxt_dsd,
+		    &difctx->ldif_dma_hndl_list, list) {
+			list_del(&dif_dsd->list);
+			dma_pool_free(ha->dif_bundl_pool, dif_dsd->dsd_addr,
+			    dif_dsd->dsd_list_dma);
+			kfree(dif_dsd);
+			difctx->no_dif_bundl--;
+		}
+
+		list_for_each_entry_safe(dif_dsd, nxt_dsd,
+		    &difctx->ldif_dsd_list, list) {
+			list_del(&dif_dsd->list);
+			dma_pool_free(ha->dl_dma_pool, dif_dsd->dsd_addr,
+			    dif_dsd->dsd_list_dma);
+			kfree(dif_dsd);
+			difctx->no_ldif_dsd--;
+		}
+
+		if (difctx->no_ldif_dsd) {
+			ql_dbg(ql_dbg_tgt+ql_dbg_verbose, sp->vha, 0xe022,
+			    "%s: difctx->no_ldif_dsd=%x\n",
+			    __func__, difctx->no_ldif_dsd);
+		}
+
+		if (difctx->no_dif_bundl) {
+			ql_dbg(ql_dbg_tgt+ql_dbg_verbose, sp->vha, 0xe022,
+			    "%s: difctx->no_dif_bundl=%x\n",
+			    __func__, difctx->no_dif_bundl);
+		}
+		sp->flags &= ~SRB_DIF_BUNDL_DMA_VALID;
 	}
+
 end:
 	CMD_SP(cmd) = NULL;
 	qla2xxx_rel_qpair_sp(sp->qpair, sp);
@@ -4017,9 +4061,86 @@ qla2x00_mem_alloc(struct qla_hw_data *ha, uint16_t req_len, uint16_t rsp_len,
 			    "Failed to allocate memory for fcp_cmnd_dma_pool.\n");
 			goto fail_dl_dma_pool;
 		}
+
+		if (ql2xenabledif) {
+			u64 bufsize = DIF_BUNDLING_DMA_POOL_SIZE;
+			struct dsd_dma *dsd, *nxt;
+			uint i;
+			/* Creata a DMA pool of buffers for DIF bundling */
+			ha->dif_bundl_pool = dma_pool_create(name,
+			    &ha->pdev->dev, DIF_BUNDLING_DMA_POOL_SIZE, 8, 0);
+			if (!ha->dif_bundl_pool) {
+				ql_dbg_pci(ql_dbg_init, ha->pdev, 0x0024,
+				    "%s: failed create dif_bundl_pool\n",
+				    __func__);
+				goto fail_dif_bundl_dma_pool;
+			}
+
+			INIT_LIST_HEAD(&ha->pool.good.head);
+			INIT_LIST_HEAD(&ha->pool.unusable.head);
+			ha->pool.good.count = 0;
+			ha->pool.unusable.count = 0;
+			for (i = 0; i < 128; i++) {
+				dsd = kzalloc(sizeof(*dsd), GFP_ATOMIC);
+				if (!dsd) {
+					ql_dbg_pci(ql_dbg_init, ha->pdev,
+					    0xe0ee, "%s: failed alloc dsd\n",
+					    __func__);
+					return 1;
+				}
+				ha->dif_bundle_kallocs++;
+
+				dsd->dsd_addr = dma_pool_alloc(
+				    ha->dif_bundl_pool, GFP_ATOMIC,
+				    &dsd->dsd_list_dma);
+				if (!dsd->dsd_addr) {
+					ql_dbg_pci(ql_dbg_init, ha->pdev,
+					    0xe0ee,
+					    "%s: failed alloc ->dsd_addr\n",
+					    __func__);
+					kfree(dsd);
+					ha->dif_bundle_kallocs--;
+					continue;
+				}
+				ha->dif_bundle_dma_allocs++;
+
+				/*
+				 * if DMA buffer crosses 4G boundary,
+				 * put it on bad list
+				 */
+				if (MSD(dsd->dsd_list_dma) ^
+				    MSD(dsd->dsd_list_dma + bufsize)) {
+					list_add_tail(&dsd->list,
+					    &ha->pool.unusable.head);
+					ha->pool.unusable.count++;
+				} else {
+					list_add_tail(&dsd->list,
+					    &ha->pool.good.head);
+					ha->pool.good.count++;
+				}
+			}
+
+			/* return the good ones back to the pool */
+			list_for_each_entry_safe(dsd, nxt,
+			    &ha->pool.good.head, list) {
+				list_del(&dsd->list);
+				dma_pool_free(ha->dif_bundl_pool,
+				    dsd->dsd_addr, dsd->dsd_list_dma);
+				ha->dif_bundle_dma_allocs--;
+				kfree(dsd);
+				ha->dif_bundle_kallocs--;
+			}
+
+			ql_dbg_pci(ql_dbg_init, ha->pdev, 0x0024,
+			    "%s: dif dma pool (good=%u unusable=%u)\n",
+			    __func__, ha->pool.good.count,
+			    ha->pool.unusable.count);
+		}
+
 		ql_dbg_pci(ql_dbg_init, ha->pdev, 0x0025,
-		    "dl_dma_pool=%p fcp_cmnd_dma_pool=%p.\n",
-		    ha->dl_dma_pool, ha->fcp_cmnd_dma_pool);
+		    "dl_dma_pool=%p fcp_cmnd_dma_pool=%p dif_bundl_pool=%p.\n",
+		    ha->dl_dma_pool, ha->fcp_cmnd_dma_pool,
+		    ha->dif_bundl_pool);
 	}
 
 	/* Allocate memory for SNS commands */
@@ -4184,6 +4305,24 @@ fail_free_ms_iocb:
 		dma_free_coherent(&ha->pdev->dev, sizeof(struct sns_cmd_pkt),
 		    ha->sns_cmd, ha->sns_cmd_dma);
 fail_dma_pool:
+	if (ql2xenabledif) {
+		struct dsd_dma *dsd, *nxt;
+
+		list_for_each_entry_safe(dsd, nxt, &ha->pool.unusable.head,
+		    list) {
+			list_del(&dsd->list);
+			dma_pool_free(ha->dif_bundl_pool, dsd->dsd_addr,
+			    dsd->dsd_list_dma);
+			ha->dif_bundle_dma_allocs--;
+			kfree(dsd);
+			ha->dif_bundle_kallocs--;
+			ha->pool.unusable.count--;
+		}
+		dma_pool_destroy(ha->dif_bundl_pool);
+		ha->dif_bundl_pool = NULL;
+	}
+
+fail_dif_bundl_dma_pool:
 	if (IS_QLA82XX(ha) || ql2xenabledif) {
 		dma_pool_destroy(ha->fcp_cmnd_dma_pool);
 		ha->fcp_cmnd_dma_pool = NULL;
@@ -4564,6 +4703,32 @@ qla2x00_mem_free(struct qla_hw_data *ha)
 
 	mempool_destroy(ha->ctx_mempool);
 
+	if (ql2xenabledif) {
+		struct dsd_dma *dsd, *nxt;
+
+		list_for_each_entry_safe(dsd, nxt, &ha->pool.unusable.head,
+					 list) {
+			list_del(&dsd->list);
+			dma_pool_free(ha->dif_bundl_pool, dsd->dsd_addr,
+				      dsd->dsd_list_dma);
+			ha->dif_bundle_dma_allocs--;
+			kfree(dsd);
+			ha->dif_bundle_kallocs--;
+			ha->pool.unusable.count--;
+		}
+		list_for_each_entry_safe(dsd, nxt, &ha->pool.good.head, list) {
+			list_del(&dsd->list);
+			dma_pool_free(ha->dif_bundl_pool, dsd->dsd_addr,
+				      dsd->dsd_list_dma);
+			ha->dif_bundle_dma_allocs--;
+			kfree(dsd);
+			ha->dif_bundle_kallocs--;
+		}
+	}
+
+	if (ha->dif_bundl_pool)
+		dma_pool_destroy(ha->dif_bundl_pool);
+
 	qlt_mem_free(ha);
 
 	if (ha->init_cb)