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, 273 insertions, 62 deletions

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 032635321ad6..65ba0e36ee60 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -1098,88 +1098,300 @@ qla24xx_walk_and_build_sglist(struct qla_hw_data *ha, srb_t *sp, uint32_t *dsd,
 
 int
 qla24xx_walk_and_build_prot_sglist(struct qla_hw_data *ha, srb_t *sp,
-	uint32_t *dsd, uint16_t tot_dsds, struct qla_tc_param *tc)
+    uint32_t *cur_dsd, uint16_t tot_dsds, struct qla_tgt_cmd *tc)
 {
-	void *next_dsd;
-	uint8_t avail_dsds = 0;
-	uint32_t dsd_list_len;
-	struct dsd_dma *dsd_ptr;
+	struct dsd_dma *dsd_ptr = NULL, *dif_dsd, *nxt_dsd;
 	struct scatterlist *sg, *sgl;
-	int	i;
-	struct scsi_cmnd *cmd;
-	uint32_t *cur_dsd = dsd;
-	uint16_t used_dsds = tot_dsds;
+	struct crc_context *difctx = NULL;
 	struct scsi_qla_host *vha;
+	uint dsd_list_len;
+	uint avail_dsds = 0;
+	uint used_dsds = tot_dsds;
+	bool dif_local_dma_alloc = false;
+	bool direction_to_device = false;
+	int i;
 
 	if (sp) {
-		cmd = GET_CMD_SP(sp);
+		struct scsi_cmnd *cmd = GET_CMD_SP(sp);
 		sgl = scsi_prot_sglist(cmd);
 		vha = sp->vha;
+		difctx = sp->u.scmd.ctx;
+		direction_to_device = cmd->sc_data_direction == DMA_TO_DEVICE;
+		ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe021,
+		  "%s: scsi_cmnd: %p, crc_ctx: %p, sp: %p\n",
+			__func__, cmd, difctx, sp);
 	} else if (tc) {
 		vha = tc->vha;
 		sgl = tc->prot_sg;
+		difctx = tc->ctx;
+		direction_to_device = tc->dma_data_direction == DMA_TO_DEVICE;
 	} else {
 		BUG();
 		return 1;
 	}
 
-	ql_dbg(ql_dbg_tgt, vha, 0xe021,
-		"%s: enter\n", __func__);
-
-	for_each_sg(sgl, sg, tot_dsds, i) {
-		dma_addr_t	sle_dma;
-
-		/* Allocate additional continuation packets? */
-		if (avail_dsds == 0) {
-			avail_dsds = (used_dsds > QLA_DSDS_PER_IOCB) ?
-						QLA_DSDS_PER_IOCB : used_dsds;
-			dsd_list_len = (avail_dsds + 1) * 12;
-			used_dsds -= avail_dsds;
-
-			/* allocate tracking DS */
-			dsd_ptr = kzalloc(sizeof(struct dsd_dma), GFP_ATOMIC);
-			if (!dsd_ptr)
-				return 1;
-
-			/* allocate new list */
-			dsd_ptr->dsd_addr = next_dsd =
-			    dma_pool_alloc(ha->dl_dma_pool, GFP_ATOMIC,
-				&dsd_ptr->dsd_list_dma);
-
-			if (!next_dsd) {
-				/*
-				 * Need to cleanup only this dsd_ptr, rest
-				 * will be done by sp_free_dma()
-				 */
-				kfree(dsd_ptr);
-				return 1;
+	ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe021,
+	    "%s: enter (write=%u)\n", __func__, direction_to_device);
+
+	/* if initiator doing write or target doing read */
+	if (direction_to_device) {
+		for_each_sg(sgl, sg, tot_dsds, i) {
+			dma_addr_t sle_phys = sg_phys(sg);
+
+			/* If SGE addr + len flips bits in upper 32-bits */
+			if (MSD(sle_phys + sg->length) ^ MSD(sle_phys)) {
+				ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe022,
+				    "%s: page boundary crossing (phys=%llx len=%x)\n",
+				    __func__, sle_phys, sg->length);
+
+				if (difctx) {
+					ha->dif_bundle_crossed_pages++;
+					dif_local_dma_alloc = true;
+				} else {
+					ql_dbg(ql_dbg_tgt + ql_dbg_verbose,
+					    vha, 0xe022,
+					    "%s: difctx pointer is NULL\n",
+					    __func__);
+				}
+				break;
+			}
+		}
+		ha->dif_bundle_writes++;
+	} else {
+		ha->dif_bundle_reads++;
+	}
+
+	if (ql2xdifbundlinginternalbuffers)
+		dif_local_dma_alloc = direction_to_device;
+
+	if (dif_local_dma_alloc) {
+		u32 track_difbundl_buf = 0;
+		u32 ldma_sg_len = 0;
+		u8 ldma_needed = 1;
+
+		difctx->no_dif_bundl = 0;
+		difctx->dif_bundl_len = 0;
+
+		/* Track DSD buffers */
+		INIT_LIST_HEAD(&difctx->ldif_dsd_list);
+		/* Track local DMA buffers */
+		INIT_LIST_HEAD(&difctx->ldif_dma_hndl_list);
+
+		for_each_sg(sgl, sg, tot_dsds, i) {
+			u32 sglen = sg_dma_len(sg);
+
+			ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe023,
+			    "%s: sg[%x] (phys=%llx sglen=%x) ldma_sg_len: %x dif_bundl_len: %x ldma_needed: %x\n",
+			    __func__, i, sg_phys(sg), sglen, ldma_sg_len,
+			    difctx->dif_bundl_len, ldma_needed);
+
+			while (sglen) {
+				u32 xfrlen = 0;
+
+				if (ldma_needed) {
+					/*
+					 * Allocate list item to store
+					 * the DMA buffers
+					 */
+					dsd_ptr = kzalloc(sizeof(*dsd_ptr),
+					    GFP_ATOMIC);
+					if (!dsd_ptr) {
+						ql_dbg(ql_dbg_tgt, vha, 0xe024,
+						    "%s: failed alloc dsd_ptr\n",
+						    __func__);
+						return 1;
+					}
+					ha->dif_bundle_kallocs++;
+
+					/* allocate dma buffer */
+					dsd_ptr->dsd_addr = dma_pool_alloc
+						(ha->dif_bundl_pool, GFP_ATOMIC,
+						 &dsd_ptr->dsd_list_dma);
+					if (!dsd_ptr->dsd_addr) {
+						ql_dbg(ql_dbg_tgt, vha, 0xe024,
+						    "%s: failed alloc ->dsd_ptr\n",
+						    __func__);
+						/*
+						 * need to cleanup only this
+						 * dsd_ptr rest will be done
+						 * by sp_free_dma()
+						 */
+						kfree(dsd_ptr);
+						ha->dif_bundle_kallocs--;
+						return 1;
+					}
+					ha->dif_bundle_dma_allocs++;
+					ldma_needed = 0;
+					difctx->no_dif_bundl++;
+					list_add_tail(&dsd_ptr->list,
+					    &difctx->ldif_dma_hndl_list);
+				}
+
+				/* xfrlen is min of dma pool size and sglen */
+				xfrlen = (sglen >
+				   (DIF_BUNDLING_DMA_POOL_SIZE - ldma_sg_len)) ?
+				    DIF_BUNDLING_DMA_POOL_SIZE - ldma_sg_len :
+				    sglen;
+
+				/* replace with local allocated dma buffer */
+				sg_pcopy_to_buffer(sgl, sg_nents(sgl),
+				    dsd_ptr->dsd_addr + ldma_sg_len, xfrlen,
+				    difctx->dif_bundl_len);
+				difctx->dif_bundl_len += xfrlen;
+				sglen -= xfrlen;
+				ldma_sg_len += xfrlen;
+				if (ldma_sg_len == DIF_BUNDLING_DMA_POOL_SIZE ||
+				    sg_is_last(sg)) {
+					ldma_needed = 1;
+					ldma_sg_len = 0;
+				}
 			}
+		}
 
-			if (sp) {
-				list_add_tail(&dsd_ptr->list,
-				    &((struct crc_context *)
-					    sp->u.scmd.ctx)->dsd_list);
+		track_difbundl_buf = used_dsds = difctx->no_dif_bundl;
+		ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe025,
+		    "dif_bundl_len=%x, no_dif_bundl=%x track_difbundl_buf: %x\n",
+		    difctx->dif_bundl_len, difctx->no_dif_bundl,
+		    track_difbundl_buf);
 
-				sp->flags |= SRB_CRC_CTX_DSD_VALID;
-			} else {
-				list_add_tail(&dsd_ptr->list,
-				    &(tc->ctx->dsd_list));
-				*tc->ctx_dsd_alloced = 1;
+		if (sp)
+			sp->flags |= SRB_DIF_BUNDL_DMA_VALID;
+		else
+			tc->prot_flags = DIF_BUNDL_DMA_VALID;
+
+		list_for_each_entry_safe(dif_dsd, nxt_dsd,
+		    &difctx->ldif_dma_hndl_list, list) {
+			u32 sglen = (difctx->dif_bundl_len >
+			    DIF_BUNDLING_DMA_POOL_SIZE) ?
+			    DIF_BUNDLING_DMA_POOL_SIZE : difctx->dif_bundl_len;
+
+			BUG_ON(track_difbundl_buf == 0);
+
+			/* Allocate additional continuation packets? */
+			if (avail_dsds == 0) {
+				ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha,
+				    0xe024,
+				    "%s: adding continuation iocb's\n",
+				    __func__);
+				avail_dsds = (used_dsds > QLA_DSDS_PER_IOCB) ?
+				    QLA_DSDS_PER_IOCB : used_dsds;
+				dsd_list_len = (avail_dsds + 1) * 12;
+				used_dsds -= avail_dsds;
+
+				/* allocate tracking DS */
+				dsd_ptr = kzalloc(sizeof(*dsd_ptr), GFP_ATOMIC);
+				if (!dsd_ptr) {
+					ql_dbg(ql_dbg_tgt, vha, 0xe026,
+					    "%s: failed alloc dsd_ptr\n",
+					    __func__);
+					return 1;
+				}
+				ha->dif_bundle_kallocs++;
+
+				difctx->no_ldif_dsd++;
+				/* allocate new list */
+				dsd_ptr->dsd_addr =
+				    dma_pool_alloc(ha->dl_dma_pool, GFP_ATOMIC,
+					&dsd_ptr->dsd_list_dma);
+				if (!dsd_ptr->dsd_addr) {
+					ql_dbg(ql_dbg_tgt, vha, 0xe026,
+					    "%s: failed alloc ->dsd_addr\n",
+					    __func__);
+					/*
+					 * need to cleanup only this dsd_ptr
+					 *  rest will be done by sp_free_dma()
+					 */
+					kfree(dsd_ptr);
+					ha->dif_bundle_kallocs--;
+					return 1;
+				}
+				ha->dif_bundle_dma_allocs++;
+
+				if (sp) {
+					list_add_tail(&dsd_ptr->list,
+					    &difctx->ldif_dsd_list);
+					sp->flags |= SRB_CRC_CTX_DSD_VALID;
+				} else {
+					list_add_tail(&dsd_ptr->list,
+					    &difctx->ldif_dsd_list);
+					tc->ctx_dsd_alloced = 1;
+				}
+
+				/* add new list to cmd iocb or last list */
+				*cur_dsd++ =
+				    cpu_to_le32(LSD(dsd_ptr->dsd_list_dma));
+				*cur_dsd++ =
+				    cpu_to_le32(MSD(dsd_ptr->dsd_list_dma));
+				*cur_dsd++ = dsd_list_len;
+				cur_dsd = dsd_ptr->dsd_addr;
 			}
-
-			/* add new list to cmd iocb or last list */
-			*cur_dsd++ = cpu_to_le32(LSD(dsd_ptr->dsd_list_dma));
-			*cur_dsd++ = cpu_to_le32(MSD(dsd_ptr->dsd_list_dma));
-			*cur_dsd++ = dsd_list_len;
-			cur_dsd = (uint32_t *)next_dsd;
+			*cur_dsd++ = cpu_to_le32(LSD(dif_dsd->dsd_list_dma));
+			*cur_dsd++ = cpu_to_le32(MSD(dif_dsd->dsd_list_dma));
+			*cur_dsd++ = cpu_to_le32(sglen);
+			avail_dsds--;
+			difctx->dif_bundl_len -= sglen;
+			track_difbundl_buf--;
 		}
-		sle_dma = sg_dma_address(sg);
-
-		*cur_dsd++ = cpu_to_le32(LSD(sle_dma));
-		*cur_dsd++ = cpu_to_le32(MSD(sle_dma));
-		*cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
 
-		avail_dsds--;
+		ql_dbg(ql_dbg_tgt + ql_dbg_verbose, vha, 0xe026,
+		    "%s: no_ldif_dsd:%x, no_dif_bundl:%x\n", __func__,
+			difctx->no_ldif_dsd, difctx->no_dif_bundl);
+	} else {
+		for_each_sg(sgl, sg, tot_dsds, i) {
+			dma_addr_t sle_dma;
+
+			/* Allocate additional continuation packets? */
+			if (avail_dsds == 0) {
+				avail_dsds = (used_dsds > QLA_DSDS_PER_IOCB) ?
+				    QLA_DSDS_PER_IOCB : used_dsds;
+				dsd_list_len = (avail_dsds + 1) * 12;
+				used_dsds -= avail_dsds;
+
+				/* allocate tracking DS */
+				dsd_ptr = kzalloc(sizeof(*dsd_ptr), GFP_ATOMIC);
+				if (!dsd_ptr) {
+					ql_dbg(ql_dbg_tgt + ql_dbg_verbose,
+					    vha, 0xe027,
+					    "%s: failed alloc dsd_dma...\n",
+					    __func__);
+					return 1;
+				}
+
+				/* allocate new list */
+				dsd_ptr->dsd_addr =
+				    dma_pool_alloc(ha->dl_dma_pool, GFP_ATOMIC,
+					&dsd_ptr->dsd_list_dma);
+				if (!dsd_ptr->dsd_addr) {
+					/* need to cleanup only this dsd_ptr */
+					/* rest will be done by sp_free_dma() */
+					kfree(dsd_ptr);
+					return 1;
+				}
+
+				if (sp) {
+					list_add_tail(&dsd_ptr->list,
+					    &difctx->dsd_list);
+					sp->flags |= SRB_CRC_CTX_DSD_VALID;
+				} else {
+					list_add_tail(&dsd_ptr->list,
+					    &difctx->dsd_list);
+					tc->ctx_dsd_alloced = 1;
+				}
+
+				/* add new list to cmd iocb or last list */
+				*cur_dsd++ =
+				    cpu_to_le32(LSD(dsd_ptr->dsd_list_dma));
+				*cur_dsd++ =
+				    cpu_to_le32(MSD(dsd_ptr->dsd_list_dma));
+				*cur_dsd++ = dsd_list_len;
+				cur_dsd = dsd_ptr->dsd_addr;
+			}
+			sle_dma = sg_dma_address(sg);
+			*cur_dsd++ = cpu_to_le32(LSD(sle_dma));
+			*cur_dsd++ = cpu_to_le32(MSD(sle_dma));
+			*cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
+			avail_dsds--;
+		}
 	}
 	/* Null termination */
 	*cur_dsd++ = 0;
@@ -1187,7 +1399,6 @@ qla24xx_walk_and_build_prot_sglist(struct qla_hw_data *ha, srb_t *sp,
 	*cur_dsd++ = 0;
 	return 0;
 }
-
 /**
  * qla24xx_build_scsi_crc_2_iocbs() - Build IOCB command utilizing Command
  *							Type 6 IOCB types.