scsi: mpt3sas: Force chain buffer allocations to be within same 4 GB region

According to the MPI specification, chain buffers can not cross a 4 GB
boundary.

While allocating, if any buffer crosses the 4 GB boundary, then:

 - Release the already allocated memory pools; and

 - Reallocate them by changing the DMA coherent mask to 32-bit

Link: https://lore.kernel.org/r/20210305102904.7560-3-suganath-prabu.subramani@broadcom.com
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 5be85ff..fa593d3 100644 (file)
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -5481,6 +5481,52 @@ _base_allocate_pcie_sgl_pool(struct MPT3SAS_ADAPTER *ioc, u32 sz)
 }
 
 /**
+ * _base_allocate_chain_dma_pool - Allocating DMA'able memory
+ *                     for chain dma pool.
+ * @ioc: Adapter object
+ * @sz: DMA Pool size
+ * @ctr: Chain tracker
+ * Return: 0 for success, non-zero for failure.
+ */
+static int
+_base_allocate_chain_dma_pool(struct MPT3SAS_ADAPTER *ioc, u32 sz)
+{
+       int i = 0, j = 0;
+       struct chain_tracker *ctr;
+
+       ioc->chain_dma_pool = dma_pool_create("chain pool", &ioc->pdev->dev,
+           ioc->chain_segment_sz, 16, 0);
+       if (!ioc->chain_dma_pool)
+               return -ENOMEM;
+
+       for (i = 0; i < ioc->scsiio_depth; i++) {
+               for (j = ioc->chains_per_prp_buffer;
+                   j < ioc->chains_needed_per_io; j++) {
+                       ctr = &ioc->chain_lookup[i].chains_per_smid[j];
+                       ctr->chain_buffer = dma_pool_alloc(ioc->chain_dma_pool,
+                           GFP_KERNEL, &ctr->chain_buffer_dma);
+                       if (!ctr->chain_buffer)
+                               return -EAGAIN;
+                       if (!mpt3sas_check_same_4gb_region((long)
+                           ctr->chain_buffer, ioc->chain_segment_sz)) {
+                               ioc_err(ioc,
+                                   "Chain buffers are not in same 4G !!! Chain buff (0x%p) dma = (0x%llx)\n",
+                                   ctr->chain_buffer,
+                                   (unsigned long long)ctr->chain_buffer_dma);
+                               ioc->use_32bit_dma = true;
+                               return -EAGAIN;
+                       }
+               }
+       }
+       dinitprintk(ioc, ioc_info(ioc,
+           "chain_lookup depth (%d), frame_size(%d), pool_size(%d kB)\n",
+           ioc->scsiio_depth, ioc->chain_segment_sz, ((ioc->scsiio_depth *
+           (ioc->chains_needed_per_io - ioc->chains_per_prp_buffer) *
+           ioc->chain_segment_sz))/1024));
+       return 0;
+}
+
+/**
  * base_alloc_rdpq_dma_pool - Allocating DMA'able memory
  *                     for reply queues.
  * @ioc: per adapter object
@@ -5577,9 +5623,8 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
        u16 max_request_credit, nvme_blocks_needed;
        unsigned short sg_tablesize;
        u16 sge_size;
-       int i, j;
+       int i;
        int ret = 0, rc = 0;
-       struct chain_tracker *ct;
 
        dinitprintk(ioc, ioc_info(ioc, "%s\n", __func__));
 
@@ -5906,31 +5951,17 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
                total_sz += sz * ioc->scsiio_depth;
        }
 
-       ioc->chain_dma_pool = dma_pool_create("chain pool", &ioc->pdev->dev,
-           ioc->chain_segment_sz, 16, 0);
-       if (!ioc->chain_dma_pool) {
-               ioc_err(ioc, "chain_dma_pool: dma_pool_create failed\n");
-               goto out;
-       }
-       for (i = 0; i < ioc->scsiio_depth; i++) {
-               for (j = ioc->chains_per_prp_buffer;
-                               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,
-                                       &ct->chain_buffer_dma);
-                       if (!ct->chain_buffer) {
-                               ioc_err(ioc, "chain_lookup: pci_pool_alloc failed\n");
-                               goto out;
-                       }
-               }
-               total_sz += ioc->chain_segment_sz;
-       }
-
+       rc = _base_allocate_chain_dma_pool(ioc, ioc->chain_segment_sz);
+       if (rc == -ENOMEM)
+               return -ENOMEM;
+       else if (rc == -EAGAIN)
+               goto try_32bit_dma;
+       total_sz += ioc->chain_segment_sz * ((ioc->chains_needed_per_io -
+               ioc->chains_per_prp_buffer) * ioc->scsiio_depth);
        dinitprintk(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));
+           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;