From 3c1a30df6d9c21c3235b6af5f25da2765b19d05b Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 18 Jun 2019 09:37:45 +0800 Subject: scsi: mvumi: use sg helper to iterate over scatterlist Unlike the legacy I/O path, scsi-mq preallocates a large array to hold the scatterlist for each request. This static allocation can consume substantial amounts of memory on modern controllers which support a large number of concurrently outstanding requests. To facilitate a switch to a smaller static allocation combined with a dynamic allocation for requests that need it, we need to make sure all SCSI drivers handle chained scatterlists correctly. Convert remaining drivers that directly dereference the scatterlist array to using the iterator functions. [mkp: clarified commit message and folded in build fix reported by zeroday] Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Ewan D. Milne Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- drivers/scsi/mvumi.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers/scsi/mvumi.c') diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c index a5410615edac..53f3563aca22 100644 --- a/drivers/scsi/mvumi.c +++ b/drivers/scsi/mvumi.c @@ -211,23 +211,22 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, struct scsi_cmnd *scmd, unsigned int sgnum = scsi_sg_count(scmd); dma_addr_t busaddr; - sg = scsi_sglist(scmd); - *sg_count = dma_map_sg(&mhba->pdev->dev, sg, sgnum, + *sg_count = dma_map_sg(&mhba->pdev->dev, scsi_sglist(scmd), sgnum, scmd->sc_data_direction); if (*sg_count > mhba->max_sge) { dev_err(&mhba->pdev->dev, "sg count[0x%x] is bigger than max sg[0x%x].\n", *sg_count, mhba->max_sge); - dma_unmap_sg(&mhba->pdev->dev, sg, sgnum, + dma_unmap_sg(&mhba->pdev->dev, scsi_sglist(scmd), sgnum, scmd->sc_data_direction); return -1; } - for (i = 0; i < *sg_count; i++) { - busaddr = sg_dma_address(&sg[i]); + scsi_for_each_sg(scmd, sg, *sg_count, i) { + busaddr = sg_dma_address(sg); m_sg->baseaddr_l = cpu_to_le32(lower_32_bits(busaddr)); m_sg->baseaddr_h = cpu_to_le32(upper_32_bits(busaddr)); m_sg->flags = 0; - sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(&sg[i]))); + sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(sg))); if ((i + 1) == *sg_count) m_sg->flags |= 1U << mhba->eot_flag; -- cgit v1.2.3