[PATCH 3/7] mpt3sas: Handle sense buffer DMA allocations in same 4G region

[Suganath Prabu S <suganath-prabu.subramani@broadcom.com>]

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According to MPI Specification Sense buffers should not cross
4GB boundary. So while allocating Sense buffers, if any buffer
crosses the 4GB boundary then,
* Release the already allocated memory pools and
* Reallocate them by changing the DMA coherent mask to 32 bit.

Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c | 86 ++++++++++++++---------------
 1 file changed, 40 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 7542f7a..6ef4925 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -5527,6 +5527,38 @@ _base_allocate_chain_dma_pool(struct MPT3SAS_ADAPTER *ioc, u32 sz)
 	return 0;
 }
 
+/**
+ * _base_allocate_sense_dma_pool - Allocating DMA'able memory
+ *			for sense dma pool.
+ * @ioc: Adapter object
+ * @sz: DMA Pool size
+ * Return: 0 for success, non-zero for failure.
+ */
+static int
+_base_allocate_sense_dma_pool(struct MPT3SAS_ADAPTER *ioc, u32 sz)
+{
+	ioc->sense_dma_pool =
+	    dma_pool_create("sense pool", &ioc->pdev->dev, sz, 4, 0);
+	if (!ioc->sense_dma_pool)
+		return -ENOMEM;
+	ioc->sense = dma_pool_alloc(ioc->sense_dma_pool,
+	    GFP_KERNEL, &ioc->sense_dma);
+	if (!ioc->sense)
+		return -EAGAIN;
+	if (!mpt3sas_check_same_4gb_region((long)ioc->sense, sz)) {
+		dinitprintk(ioc, pr_err(
+		    "Bad Sense Pool! sense (0x%p) sense_dma = (0x%llx)\n",
+		    ioc->sense, (unsigned long long) ioc->sense_dma));
+		ioc->use_32bit_dma = true;
+		return -EAGAIN;
+	}
+	ioc_info(ioc,
+	    "sense pool(0x%p) - dma(0x%llx): depth(%d), element_size(%d), pool_size (%d kB)\n",
+	    ioc->sense, (unsigned long long)ioc->sense_dma,
+	    ioc->scsiio_depth, SCSI_SENSE_BUFFERSIZE, sz/1024);
+	return 0;
+}
+
 /**
  * base_alloc_rdpq_dma_pool - Allocating DMA'able memory
  *                     for reply queues.
@@ -5620,7 +5652,7 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 	u16 chains_needed_per_io;
 	u32 sz, total_sz, reply_post_free_sz, reply_post_free_array_sz;
 	u32 retry_sz;
-	u32 rdpq_sz = 0;
+	u32 rdpq_sz = 0, sense_sz = 0;
 	u16 max_request_credit, nvme_blocks_needed;
 	unsigned short sg_tablesize;
 	u16 sge_size;
@@ -5963,58 +5995,20 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 	    ioc_info(ioc, "chain pool depth(%d), frame_size(%d), pool_size(%d kB)\n",
 	    ioc->chain_depth, ioc->chain_segment_sz,
 	    (ioc->chain_depth * ioc->chain_segment_sz) / 1024));
-
 	/* sense buffers, 4 byte align */
-	sz = ioc->scsiio_depth * SCSI_SENSE_BUFFERSIZE;
-	ioc->sense_dma_pool = dma_pool_create("sense pool", &ioc->pdev->dev, sz,
-					      4, 0);
-	if (!ioc->sense_dma_pool) {
-		ioc_err(ioc, "sense pool: dma_pool_create failed\n");
-		goto out;
-	}
-	ioc->sense = dma_pool_alloc(ioc->sense_dma_pool, GFP_KERNEL,
-	    &ioc->sense_dma);
-	if (!ioc->sense) {
-		ioc_err(ioc, "sense pool: dma_pool_alloc failed\n");
-		goto out;
-	}
-	/* sense buffer requires to be in same 4 gb region.
-	 * Below function will check the same.
-	 * In case of failure, new pci pool will be created with updated
-	 * alignment. Older allocation and pool will be destroyed.
-	 * Alignment will be used such a way that next allocation if
-	 * success, will always meet same 4gb region requirement.
-	 * Actual requirement is not alignment, but we need start and end of
-	 * DMA address must have same upper 32 bit address.
-	 */
-	if (!mpt3sas_check_same_4gb_region((long)ioc->sense, sz)) {
-		//Release Sense pool & Reallocate
-		dma_pool_free(ioc->sense_dma_pool, ioc->sense, ioc->sense_dma);
-		dma_pool_destroy(ioc->sense_dma_pool);
-		ioc->sense = NULL;
-
-		ioc->sense_dma_pool =
-			dma_pool_create("sense pool", &ioc->pdev->dev, sz,
-						roundup_pow_of_two(sz), 0);
-		if (!ioc->sense_dma_pool) {
-			ioc_err(ioc, "sense pool: pci_pool_create failed\n");
-			goto out;
-		}
-		ioc->sense = dma_pool_alloc(ioc->sense_dma_pool, GFP_KERNEL,
-				&ioc->sense_dma);
-		if (!ioc->sense) {
-			ioc_err(ioc, "sense pool: pci_pool_alloc failed\n");
-			goto out;
-		}
-	}
+	sense_sz = ioc->scsiio_depth * SCSI_SENSE_BUFFERSIZE;
+	rc = _base_allocate_sense_dma_pool(ioc, sense_sz);
+	if (rc  == -ENOMEM)
+		return -ENOMEM;
+	else if (rc == -EAGAIN)
+		goto try_32bit_dma;
+	total_sz += sense_sz;
 	ioc_info(ioc,
 	    "sense pool(0x%p)- dma(0x%llx): depth(%d),"
 	    "element_size(%d), pool_size(%d kB)\n",
 	    ioc->sense, (unsigned long long)ioc->sense_dma, ioc->scsiio_depth,
 	    SCSI_SENSE_BUFFERSIZE, sz / 1024);
 
-	total_sz += sz;
-
 	/* reply pool, 4 byte align */
 	sz = ioc->reply_free_queue_depth * ioc->reply_sz;
 	ioc->reply_dma_pool = dma_pool_create("reply pool", &ioc->pdev->dev, sz,
-- 
2.27.0


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