lkml.org 
[lkml]   [2006]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 10/15] aic94xx: Don't call pci_map_sg for already-mapped scatterlists
    Date

    It turns out that libata has already dma_map_sg'd the scatterlist
    entries that go with an ata_queued_cmd by the time it calls
    sas_ata_qc_issue. sas_ata_qc_issue passes this scatterlist to aic94xx.
    Unfortunately, aic94xx assumes that any scatterlist passed to it needs
    to be pci_map_sg'd... which blows away the mapping that libata created!
    This causes (on a x260) Calgary IOMMU table leaks and duplicate frees
    when aic94xx and libata try to {pci,dma}_unmap_sg the scatterlist.

    Since dma_map_sg and pci_map_sg are fed the same struct device, I think
    it's safe to add a flag to sas_task that tells aic94xx that it need
    not map the scatterlist. It didn't break anything on the x260, though
    I don't have any SATAPI devices handy for testing.

    Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
    ---

    drivers/scsi/aic94xx/aic94xx_task.c | 17 +++++++++++------
    drivers/scsi/libsas/sas_ata.c | 1 +
    include/scsi/libsas.h | 1 +
    3 files changed, 13 insertions(+), 6 deletions(-)

    diff --git a/drivers/scsi/aic94xx/aic94xx_task.c b/drivers/scsi/aic94xx/aic94xx_task.c
    index 466b492..f801c64 100644
    --- a/drivers/scsi/aic94xx/aic94xx_task.c
    +++ b/drivers/scsi/aic94xx/aic94xx_task.c
    @@ -74,8 +74,11 @@ static inline int asd_map_scatterlist(st
    return 0;
    }

    - num_sg = pci_map_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
    - task->data_dir);
    + if (task->external_sg)
    + num_sg = task->num_scatter;
    + else
    + num_sg = pci_map_sg(asd_ha->pcidev, task->scatter,
    + task->num_scatter, task->data_dir);
    if (num_sg == 0)
    return -ENOMEM;

    @@ -120,8 +123,9 @@ static inline int asd_map_scatterlist(st

    return 0;
    err_unmap:
    - pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
    - task->data_dir);
    + if (!task->external_sg)
    + pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
    + task->data_dir);
    return res;
    }

    @@ -142,8 +146,9 @@ static inline void asd_unmap_scatterlist
    }

    asd_free_coherent(asd_ha, ascb->sg_arr);
    - pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
    - task->data_dir);
    + if (!task->external_sg)
    + pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
    + task->data_dir);
    }

    /* ---------- Task complete tasklet ---------- */
    diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
    index 209f402..77860ab 100644
    --- a/drivers/scsi/libsas/sas_ata.c
    +++ b/drivers/scsi/libsas/sas_ata.c
    @@ -169,6 +169,7 @@ static unsigned int sas_ata_qc_issue(str
    task->num_scatter = num;
    }

    + task->external_sg = 1;
    task->data_dir = qc->dma_dir;
    task->scatter = qc->__sg;
    task->ata_task.retry_count = 1;
    diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
    index a06cbde..7dcf593 100644
    --- a/include/scsi/libsas.h
    +++ b/include/scsi/libsas.h
    @@ -538,6 +538,7 @@ struct sas_task {
    void *uldd_task;

    struct work_struct abort_work;
    + int external_sg;
    };


    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/
    \
     
     \ /
      Last update: 2006-11-17 22:07    [W:0.030 / U:0.008 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site