Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424473AbWKKA71 (ORCPT ); Fri, 10 Nov 2006 19:59:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424471AbWKKA71 (ORCPT ); Fri, 10 Nov 2006 19:59:27 -0500 Received: from e36.co.us.ibm.com ([32.97.110.154]:3740 "EHLO e36.co.us.ibm.com") by vger.kernel.org with ESMTP id S1424469AbWKKA70 (ORCPT ); Fri, 10 Nov 2006 19:59:26 -0500 Message-ID: <4555206C.8010909@us.ibm.com> Date: Fri, 10 Nov 2006 16:59:24 -0800 From: "Darrick J. Wong" Reply-To: "Darrick J. Wong" Organization: IBM LTC User-Agent: Thunderbird 1.5.0.7 (X11/20060918) MIME-Version: 1.0 To: linux-scsi , Linux Kernel Mailing List , Alexis Bruemmer Subject: [PATCH] aic94xx: Don't call pci_map_sg for already-mapped scatterlists X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3021 Lines: 89 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 to test with. Is this the correct approach to fixing this problem? -- Signed-off-by: Darrick J. Wong diff --git a/drivers/scsi/aic94xx/aic94xx_task.c b/drivers/scsi/aic94xx/aic94xx_task.c index 9840708..eaffaa6 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 8f8cd40..04115c3 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -167,6 +167,7 @@ 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 1263bd5..25a1fb3 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -546,6 +546,7 @@ 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/