Messages in this thread | | | Date | Tue, 28 Mar 2023 11:16:31 -0700 | Subject | Re: [PATCH v2 8/8] dmaengine/idxd: Re-enable kernel workqueue under DMA API | From | Fenghua Yu <> |
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Hi, Jacob,
On 3/27/23 16:21, Jacob Pan wrote: > Kernel workqueues were disabled due to flawed use of kernel VA and SVA > API. Now That we have the support for attaching PASID to the device's
s/That/that/
> default domain and the ability to reserve global PASIDs from SVA APIs, > we can re-enable the kernel work queues and use them under DMA API. > > We also use non-privileged access for in-kernel DMA to be consistent > with the IOMMU settings. Consequently, interrupt for user privilege is > enabled for work completion IRQs. > > Link:https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/ > Reviewed-by: Dave Jiang <dave.jiang@intel.com> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > --- > drivers/dma/idxd/device.c | 30 ++++------------------- > drivers/dma/idxd/init.c | 51 ++++++++++++++++++++++++++++++++++++--- > drivers/dma/idxd/sysfs.c | 7 ------ > 3 files changed, 52 insertions(+), 36 deletions(-) > > diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c > index 6fca8fa8d3a8..f6b133d61a04 100644 > --- a/drivers/dma/idxd/device.c > +++ b/drivers/dma/idxd/device.c > @@ -299,21 +299,6 @@ void idxd_wqs_unmap_portal(struct idxd_device *idxd) > } > } > > -static void __idxd_wq_set_priv_locked(struct idxd_wq *wq, int priv) > -{ > - struct idxd_device *idxd = wq->idxd; > - union wqcfg wqcfg; > - unsigned int offset; > - > - offset = WQCFG_OFFSET(idxd, wq->id, WQCFG_PRIVL_IDX); > - spin_lock(&idxd->dev_lock); > - wqcfg.bits[WQCFG_PRIVL_IDX] = ioread32(idxd->reg_base + offset); > - wqcfg.priv = priv; > - wq->wqcfg->bits[WQCFG_PRIVL_IDX] = wqcfg.bits[WQCFG_PRIVL_IDX]; > - iowrite32(wqcfg.bits[WQCFG_PRIVL_IDX], idxd->reg_base + offset); > - spin_unlock(&idxd->dev_lock); > -} > - > static void __idxd_wq_set_pasid_locked(struct idxd_wq *wq, int pasid) > { > struct idxd_device *idxd = wq->idxd; > @@ -1324,15 +1309,14 @@ int drv_enable_wq(struct idxd_wq *wq) > } > > /* > - * In the event that the WQ is configurable for pasid and priv bits. > - * For kernel wq, the driver should setup the pasid, pasid_en, and priv bit. > - * However, for non-kernel wq, the driver should only set the pasid_en bit for > - * shared wq. A dedicated wq that is not 'kernel' type will configure pasid and > + * In the event that the WQ is configurable for pasid, the driver > + * should setup the pasid, pasid_en bit. This is true for both kernel > + * and user shared workqueues. There is no need to setup priv bit in > + * that in-kernel DMA will also do user privileged requests. > + * A dedicated wq that is not 'kernel' type will configure pasid and > * pasid_en later on so there is no need to setup. > */ > if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) { > - int priv = 0; > - > if (wq_pasid_enabled(wq)) { > if (is_idxd_wq_kernel(wq) || wq_shared(wq)) { > u32 pasid = wq_dedicated(wq) ? idxd->pasid : 0; > @@ -1340,10 +1324,6 @@ int drv_enable_wq(struct idxd_wq *wq) > __idxd_wq_set_pasid_locked(wq, pasid); > } > } > - > - if (is_idxd_wq_kernel(wq)) > - priv = 1; > - __idxd_wq_set_priv_locked(wq, priv); > } > > rc = 0; > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c > index e6ee267da0ff..a3396e1b38f1 100644 > --- a/drivers/dma/idxd/init.c > +++ b/drivers/dma/idxd/init.c > @@ -506,14 +506,56 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d > > static int idxd_enable_system_pasid(struct idxd_device *idxd) > { > - return -EOPNOTSUPP; > + struct pci_dev *pdev = idxd->pdev; > + struct device *dev = &pdev->dev; > + struct iommu_domain *domain; > + union gencfg_reg gencfg; > + ioasid_t pasid; > + int ret; > + > + /* > + * Attach a global PASID to the DMA domain so that we can use ENQCMDS > + * to submit work on buffers mapped by DMA API. > + */ > + domain = iommu_get_dma_domain(dev); > + if (!domain) > + return -EPERM; > + > + pasid = iommu_sva_reserve_pasid(1, dev->iommu->max_pasids); > + if (pasid == IOMMU_PASID_INVALID) > + return -ENOSPC; > + > + ret = iommu_attach_device_pasid(domain, dev, pasid); > + if (ret) { > + dev_err(dev, "failed to attach device pasid %d, domain type %d", > + pasid, domain->type); > + iommu_sva_release_pasid(pasid); > + return ret; > + } > + > + /* Since we set user privilege for kernel DMA, enable completion IRQ */ > + gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET); > + gencfg.user_int_en = 1; > + iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET); > + idxd->pasid = pasid; > + > + return ret; > } > > static void idxd_disable_system_pasid(struct idxd_device *idxd) > { > + struct pci_dev *pdev = idxd->pdev; > + struct device *dev = &pdev->dev; > + struct iommu_domain *domain; > + > + domain = iommu_get_domain_for_dev(dev); > + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED) > + return; > > - iommu_sva_unbind_device(idxd->sva); > + iommu_detach_device_pasid(domain, dev, idxd->pasid); > + iommu_sva_release_pasid(idxd->pasid);
May need gencfg.user_int_en = 0 here.
> idxd->sva = NULL; > + idxd->pasid = IOMMU_PASID_INVALID; > } > > static int idxd_probe(struct idxd_device *idxd) > @@ -535,8 +577,9 @@ static int idxd_probe(struct idxd_device *idxd) > } else { > set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags); > > - if (idxd_enable_system_pasid(idxd)) > - dev_warn(dev, "No in-kernel DMA with PASID.\n"); > + rc = idxd_enable_system_pasid(idxd); > + if (rc) > + dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc); > else > set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags); > } > diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c > index 18cd8151dee0..c5561c00a503 100644 > --- a/drivers/dma/idxd/sysfs.c > +++ b/drivers/dma/idxd/sysfs.c > @@ -944,13 +944,6 @@ 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; > - > input = kstrndup(buf, count, GFP_KERNEL); > if (!input) > return -ENOMEM;
Thanks.
-Fenghua
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