The current in-kernel supervisor PASID support is based on the SVM/SVA machinery in SVA lib. The binding between a kernel PASID and kernel mapping has many flaws. See discussions in the link below. This patch enables in-kernel DMA by switching from SVA lib to the standard DMA mapping APIs. Since both DMA requests with and without PASIDs are mapped identically, there is no change to how DMA APIs are used after the kernel PASID is enabled. Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@xxxxxxxxxx/ Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> --- drivers/dma/idxd/idxd.h | 1 - drivers/dma/idxd/init.c | 34 +++++++++------------------------- drivers/dma/idxd/sysfs.c | 7 ------- 3 files changed, 9 insertions(+), 33 deletions(-) diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index ccbefd0be617..190b08bd7c08 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -277,7 +277,6 @@ struct idxd_device { struct idxd_wq **wqs; struct idxd_engine **engines; - struct iommu_sva *sva; unsigned int pasid; int num_groups; diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index e1b5d1e4a949..e2e1c0eae6d6 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -16,6 +16,7 @@ #include <linux/idr.h> #include <linux/intel-svm.h> #include <linux/iommu.h> +#include <linux/dma-iommu.h> #include <uapi/linux/idxd.h> #include <linux/dmaengine.h> #include "../dmaengine.h" @@ -466,36 +467,22 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d static int idxd_enable_system_pasid(struct idxd_device *idxd) { - int flags; - unsigned int pasid; - struct iommu_sva *sva; + u32 pasid; + int ret; - flags = SVM_FLAG_SUPERVISOR_MODE; - - sva = iommu_sva_bind_device(&idxd->pdev->dev, NULL, &flags); - if (IS_ERR(sva)) { - dev_warn(&idxd->pdev->dev, - "iommu sva bind failed: %ld\n", PTR_ERR(sva)); - return PTR_ERR(sva); - } - - pasid = iommu_sva_get_pasid(sva); - if (pasid == IOMMU_PASID_INVALID) { - iommu_sva_unbind_device(sva); - return -ENODEV; + ret = iommu_attach_dma_pasid(&idxd->pdev->dev, &pasid); + if (ret) { + dev_err(&idxd->pdev->dev, "No DMA PASID %d\n", ret); + return ret; } - - idxd->sva = sva; idxd->pasid = pasid; - dev_dbg(&idxd->pdev->dev, "system pasid: %u\n", pasid); + return 0; } static void idxd_disable_system_pasid(struct idxd_device *idxd) { - - iommu_sva_unbind_device(idxd->sva); - idxd->sva = NULL; + iommu_detach_dma_pasid(&idxd->pdev->dev); } static int idxd_probe(struct idxd_device *idxd) @@ -527,10 +514,7 @@ static int idxd_probe(struct idxd_device *idxd) else set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags); } - } else if (!sva) { - dev_warn(dev, "User forced SVA off via module param.\n"); } - idxd_read_caps(idxd); idxd_read_table_offsets(idxd); diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index dfd549685c46..a48928973bd4 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -839,13 +839,6 @@ static ssize_t wq_name_store(struct device *dev, if (strlen(buf) > WQ_NAME_SIZE || strlen(buf) == 0) return -EINVAL; - /* - * This is temporarily placed here until we have SVM support for - * dmaengine. - */ - if (wq->type == IDXD_WQT_KERNEL && device_pasid_enabled(wq->idxd)) - return -EOPNOTSUPP; - memset(wq->name, 0, WQ_NAME_SIZE + 1); strncpy(wq->name, buf, WQ_NAME_SIZE); strreplace(wq->name, '\n', '\0'); -- 2.25.1
