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scsi: mpi3mr: Avoid MAX_PAGE_ORDER WARNING for buffer allocations

Commit fc4444941140 ("scsi: mpi3mr: HDB allocation and posting for hardware
and firmware buffers") added mpi3mr_alloc_diag_bufs() which calls
dma_alloc_coherent() to allocate the trace buffer and the firmware
buffer. mpi3mr_alloc_diag_bufs() decides the buffer sizes from the driver
configuration. In my environment, the sizes are 8MB. With the sizes,
dma_alloc_coherent() fails and report this WARNING:

WARNING: CPU: 4 PID: 438 at mm/page_alloc.c:4676 __alloc_pages_noprof+0x52f/0x640

The WARNING indicates that the order of the allocation size is larger than
MAX_PAGE_ORDER. After this failure, mpi3mr_alloc_diag_bufs() reduces the
buffer sizes and retries dma_alloc_coherent(). In the end, the buffer
allocations succeed with 4MB size in my environment, which corresponds to
MAX_PAGE_ORDER=10. Though the allocations succeed, the WARNING message is
misleading and should be avoided.

To avoid the WARNING, check the orders of the buffer allocation sizes
before calling dma_alloc_coherent(). If the orders are larger than
MAX_PAGE_ORDER, fall back to the retry path.

Fixes: fc4444941140 ("scsi: mpi3mr: HDB allocation and posting for hardware and firmware buffers")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240810042701.661841-3-shinichiro.kawasaki@wdc.com
Acked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

authored by

Shin'ichiro Kawasaki and committed by
Martin K. Petersen 8c6b808c 6b9935da

+8 -3
+8 -3
drivers/scsi/mpi3mr/mpi3mr_app.c
··· 100 100 dprint_init(mrioc, 101 101 "trying to allocate trace diag buffer of size = %dKB\n", 102 102 trace_size / 1024); 103 - if (mpi3mr_alloc_trace_buffer(mrioc, trace_size)) { 103 + if (get_order(trace_size) > MAX_PAGE_ORDER || 104 + mpi3mr_alloc_trace_buffer(mrioc, trace_size)) { 104 105 retry = true; 105 106 trace_size -= trace_dec_size; 106 107 dprint_init(mrioc, "trace diag buffer allocation failed\n" ··· 119 118 diag_buffer->type = MPI3_DIAG_BUFFER_TYPE_FW; 120 119 diag_buffer->status = MPI3MR_HDB_BUFSTATUS_NOT_ALLOCATED; 121 120 if ((mrioc->facts.diag_fw_sz < fw_size) && (fw_size >= fw_min_size)) { 122 - diag_buffer->addr = dma_alloc_coherent(&mrioc->pdev->dev, 123 - fw_size, &diag_buffer->dma_addr, GFP_KERNEL); 121 + if (get_order(fw_size) <= MAX_PAGE_ORDER) { 122 + diag_buffer->addr 123 + = dma_alloc_coherent(&mrioc->pdev->dev, fw_size, 124 + &diag_buffer->dma_addr, 125 + GFP_KERNEL); 126 + } 124 127 if (!retry) 125 128 dprint_init(mrioc, 126 129 "%s:trying to allocate firmware diag buffer of size = %dKB\n",