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x-ms-exchange-antispam-messagedata: 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB4960.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6255fceb-949d-4f30-423b-08d87a741ad1 X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Oct 2020 12:30:35.6112 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: eXnaB/I6Ue6+7pBapakmJjAEhAVbX+qI1KhVxf+RErdKZsMyMpqwof/eVsA6w0faxH2gJs5CSD5vFpm5pFNW8A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0401MB2399 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi Christoph, Thank you for improving the code. I think your code makes vop_mmap looks cl= earer. I have tested it on imx8qm platform(arm64 architecture) and it works well. I will send the code together in v5. Best regards Sherry > Subject: Re: [PATCH V4 1/2] misc: vop: change the way of allocating vring= and > device page >=20 > This looks much better, but we need to be careful to restore the original > vm_start / vm_end. What do you think about the version below, which also > simplifies vop_mmap a lot (completely untested): >=20 > --- > From 2de72bf7444ee187a7576962d746d482c5bdd593 Mon Sep 17 00:00:00 > 2001 > From: Sherry Sun > Date: Mon, 26 Oct 2020 16:53:34 +0800 > Subject: misc: vop: change the way of allocating vring and device page >=20 > Allocate vrings use dma_alloc_coherent is a common way in kernel. As the > memory interacted between two systems should use consistent memory to > avoid caching effects, same as device page memory. >=20 > The orginal way use __get_free_pages and dma_map_single to allocate and > map vring, but not use dma_sync_single_for_cpu/device api to sync the > changes of vring between EP and RC, which will cause memory > synchronization problem for those devices which don't support hardware > dma coherent. >=20 > Also change to use dma_mmap_coherent for mmap callback to map the > device page and vring memory to userspace. >=20 > Signed-off-by: Joakim Zhang > Signed-off-by: Sherry Sun > --- > drivers/misc/mic/bus/vop_bus.h | 2 + > drivers/misc/mic/host/mic_boot.c | 9 ++ > drivers/misc/mic/host/mic_main.c | 43 +++------- > drivers/misc/mic/vop/vop_vringh.c | 135 ++++++++++++------------------ > 4 files changed, 77 insertions(+), 112 deletions(-) >=20 > diff --git a/drivers/misc/mic/bus/vop_bus.h > b/drivers/misc/mic/bus/vop_bus.h index 4fa02808c1e27d..e21c06aeda7a31 > 100644 > --- a/drivers/misc/mic/bus/vop_bus.h > +++ b/drivers/misc/mic/bus/vop_bus.h > @@ -75,6 +75,7 @@ struct vop_driver { > * node to add/remove/configure virtio devices. > * @get_dp: Get access to the virtio device page used by the self > * node to add/remove/configure virtio devices. > + * @dp_mmap: Map the virtio device page to userspace. > * @send_intr: Send an interrupt to the peer node on a specified doorbel= l. > * @remap: Map a buffer with the specified DMA address and length. > * @unmap: Unmap a buffer previously mapped. > @@ -92,6 +93,7 @@ struct vop_hw_ops { > void (*ack_interrupt)(struct vop_device *vpdev, int num); > void __iomem * (*get_remote_dp)(struct vop_device *vpdev); > void * (*get_dp)(struct vop_device *vpdev); > + int (*dp_mmap)(struct vop_device *vpdev, struct vm_area_struct > *vma); > void (*send_intr)(struct vop_device *vpdev, int db); > void __iomem * (*remap)(struct vop_device *vpdev, > dma_addr_t pa, size_t len); > diff --git a/drivers/misc/mic/host/mic_boot.c > b/drivers/misc/mic/host/mic_boot.c > index 8cb85b8b3e199b..44ed918b49b4d2 100644 > --- a/drivers/misc/mic/host/mic_boot.c > +++ b/drivers/misc/mic/host/mic_boot.c > @@ -89,6 +89,14 @@ static void *__mic_get_dp(struct vop_device *vpdev) > return mdev->dp; > } >=20 > +static int __mic_dp_mmap(struct vop_device *vpdev, struct > +vm_area_struct *vma) { > + struct mic_device *mdev =3D vpdev_to_mdev(&vpdev->dev); > + > + return dma_mmap_coherent(&mdev->pdev->dev, vma, mdev->dp, > + mdev->dp_dma_addr, MIC_DP_SIZE); > +} > + > static void __iomem *__mic_get_remote_dp(struct vop_device *vpdev) { > return NULL; > @@ -120,6 +128,7 @@ static struct vop_hw_ops vop_hw_ops =3D { > .ack_interrupt =3D __mic_ack_interrupt, > .next_db =3D __mic_next_db, > .get_dp =3D __mic_get_dp, > + .dp_mmap =3D __mic_dp_mmap, > .get_remote_dp =3D __mic_get_remote_dp, > .send_intr =3D __mic_send_intr, > .remap =3D __mic_ioremap, > diff --git a/drivers/misc/mic/host/mic_main.c > b/drivers/misc/mic/host/mic_main.c > index ea4608527ea04d..fab87a72a9a4a5 100644 > --- a/drivers/misc/mic/host/mic_main.c > +++ b/drivers/misc/mic/host/mic_main.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include >=20 > #include > #include "../common/mic_dev.h" > @@ -45,33 +46,6 @@ MODULE_DEVICE_TABLE(pci, mic_pci_tbl); > /* ID allocator for MIC devices */ > static struct ida g_mic_ida; >=20 > -/* Initialize the device page */ > -static int mic_dp_init(struct mic_device *mdev) -{ > - mdev->dp =3D kzalloc(MIC_DP_SIZE, GFP_KERNEL); > - if (!mdev->dp) > - return -ENOMEM; > - > - mdev->dp_dma_addr =3D mic_map_single(mdev, > - mdev->dp, MIC_DP_SIZE); > - if (mic_map_error(mdev->dp_dma_addr)) { > - kfree(mdev->dp); > - dev_err(&mdev->pdev->dev, "%s %d err %d\n", > - __func__, __LINE__, -ENOMEM); > - return -ENOMEM; > - } > - mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev- > >dp_dma_addr); > - mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev- > >dp_dma_addr >> 32); > - return 0; > -} > - > -/* Uninitialize the device page */ > -static void mic_dp_uninit(struct mic_device *mdev) -{ > - mic_unmap_single(mdev, mdev->dp_dma_addr, MIC_DP_SIZE); > - kfree(mdev->dp); > -} > - > /** > * mic_ops_init: Initialize HW specific operation tables. > * > @@ -227,11 +201,16 @@ static int mic_probe(struct pci_dev *pdev, >=20 > pci_set_drvdata(pdev, mdev); >=20 > - rc =3D mic_dp_init(mdev); > - if (rc) { > - dev_err(&pdev->dev, "mic_dp_init failed rc %d\n", rc); > + mdev->dp =3D dma_alloc_coherent(&pdev->dev, MIC_DP_SIZE, > + &mdev->dp_dma_addr, GFP_KERNEL); > + if (!mdev->dp) { > + dev_err(&pdev->dev, "failed to allocate device page\n"); > goto smpt_uninit; > } > + > + mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev- > >dp_dma_addr); > + mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev- > >dp_dma_addr >> 32); > + > mic_bootparam_init(mdev); > mic_create_debug_dir(mdev); >=20 > @@ -244,7 +223,7 @@ static int mic_probe(struct pci_dev *pdev, > return 0; > cleanup_debug_dir: > mic_delete_debug_dir(mdev); > - mic_dp_uninit(mdev); > + dma_free_coherent(&pdev->dev, MIC_DP_SIZE, mdev->dp, > +mdev->dp_dma_addr); > smpt_uninit: > mic_smpt_uninit(mdev); > free_interrupts: > @@ -283,7 +262,7 @@ static void mic_remove(struct pci_dev *pdev) >=20 > cosm_unregister_device(mdev->cosm_dev); > mic_delete_debug_dir(mdev); > - mic_dp_uninit(mdev); > + dma_free_coherent(&pdev->dev, MIC_DP_SIZE, mdev->dp, > +mdev->dp_dma_addr); > mic_smpt_uninit(mdev); > mic_free_interrupts(mdev, pdev); > iounmap(mdev->aper.va); > diff --git a/drivers/misc/mic/vop/vop_vringh.c > b/drivers/misc/mic/vop/vop_vringh.c > index 7014ffe88632e5..6835648d577d57 100644 > --- a/drivers/misc/mic/vop/vop_vringh.c > +++ b/drivers/misc/mic/vop/vop_vringh.c > @@ -298,9 +298,8 @@ static int vop_virtio_add_device(struct vop_vdev > *vdev, > mutex_init(&vvr->vr_mutex); > vr_size =3D PAGE_ALIGN(round_up(vring_size(num, > MIC_VIRTIO_RING_ALIGN), 4) + > sizeof(struct _mic_vring_info)); > - vr->va =3D (void *) > - __get_free_pages(GFP_KERNEL | __GFP_ZERO, > - get_order(vr_size)); > + vr->va =3D dma_alloc_coherent(vop_dev(vdev), vr_size, > &vr_addr, > + GFP_KERNEL); > if (!vr->va) { > ret =3D -ENOMEM; > dev_err(vop_dev(vdev), "%s %d err %d\n", @@ - > 310,15 +309,6 @@ static int vop_virtio_add_device(struct vop_vdev *vdev, > vr->len =3D vr_size; > vr->info =3D vr->va + round_up(vring_size(num, > MIC_VIRTIO_RING_ALIGN), 4); > vr->info->magic =3D cpu_to_le32(MIC_MAGIC + vdev->virtio_id > + i); > - vr_addr =3D dma_map_single(&vpdev->dev, vr->va, vr_size, > - DMA_BIDIRECTIONAL); > - if (dma_mapping_error(&vpdev->dev, vr_addr)) { > - free_pages((unsigned long)vr->va, > get_order(vr_size)); > - ret =3D -ENOMEM; > - dev_err(vop_dev(vdev), "%s %d err %d\n", > - __func__, __LINE__, ret); > - goto err; > - } > vqconfig[i].address =3D cpu_to_le64(vr_addr); >=20 > vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN); > @@ -339,11 +329,9 @@ static int vop_virtio_add_device(struct vop_vdev > *vdev, > dev_dbg(&vpdev->dev, > "%s %d index %d va %p info %p vr_size 0x%x\n", > __func__, __LINE__, i, vr->va, vr->info, vr_size); > - vvr->buf =3D (void *)__get_free_pages(GFP_KERNEL, > - get_order(VOP_INT_DMA_BUF_SIZE)); > - vvr->buf_da =3D dma_map_single(&vpdev->dev, > - vvr->buf, VOP_INT_DMA_BUF_SIZE, > - DMA_BIDIRECTIONAL); > + vvr->buf =3D dma_alloc_coherent(vop_dev(vdev), > + VOP_INT_DMA_BUF_SIZE, > + &vvr->buf_da, GFP_KERNEL); > } >=20 > snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index, > @@ -382,10 +370,8 @@ static int vop_virtio_add_device(struct vop_vdev > *vdev, > for (j =3D 0; j < i; j++) { > struct vop_vringh *vvr =3D &vdev->vvr[j]; >=20 > - dma_unmap_single(&vpdev->dev, > le64_to_cpu(vqconfig[j].address), > - vvr->vring.len, DMA_BIDIRECTIONAL); > - free_pages((unsigned long)vvr->vring.va, > - get_order(vvr->vring.len)); > + dma_free_coherent(vop_dev(vdev), vvr->vring.len, vvr- > >vring.va, > + le64_to_cpu(vqconfig[j].address)); > } > return ret; > } > @@ -433,17 +419,12 @@ static void vop_virtio_del_device(struct vop_vdev > *vdev) > for (i =3D 0; i < vdev->dd->num_vq; i++) { > struct vop_vringh *vvr =3D &vdev->vvr[i]; >=20 > - dma_unmap_single(&vpdev->dev, > - vvr->buf_da, VOP_INT_DMA_BUF_SIZE, > - DMA_BIDIRECTIONAL); > - free_pages((unsigned long)vvr->buf, > - get_order(VOP_INT_DMA_BUF_SIZE)); > + dma_free_coherent(vop_dev(vdev), > VOP_INT_DMA_BUF_SIZE, > + vvr->buf, vvr->buf_da); > vringh_kiov_cleanup(&vvr->riov); > vringh_kiov_cleanup(&vvr->wiov); > - dma_unmap_single(&vpdev->dev, > le64_to_cpu(vqconfig[i].address), > - vvr->vring.len, DMA_BIDIRECTIONAL); > - free_pages((unsigned long)vvr->vring.va, > - get_order(vvr->vring.len)); > + dma_free_coherent(vop_dev(vdev), vvr->vring.len, vvr- > >vring.va, > + le64_to_cpu(vqconfig[i].address)); > } > /* > * Order the type update with previous stores. This write barrier @@ > -1042,13 +1023,27 @@ static __poll_t vop_poll(struct file *f, poll_table = *wait) > return mask; > } >=20 > -static inline int > -vop_query_offset(struct vop_vdev *vdev, unsigned long offset, > - unsigned long *size, unsigned long *pa) > +/* > + * Maps the device page and virtio rings to user space for readonly acce= ss. > + */ > +static int vop_mmap(struct file *f, struct vm_area_struct *vma) > { > - struct vop_device *vpdev =3D vdev->vpdev; > - unsigned long start =3D MIC_DP_SIZE; > - int i; > + struct vop_vdev *vdev =3D f->private_data; > + struct mic_vqconfig *vqconfig =3D mic_vq_config(vdev->dd); > + unsigned long orig_start =3D vma->vm_start; > + unsigned long orig_end =3D vma->vm_end; > + int err, i; > + > + if (!vdev->vpdev->hw_ops->dp_mmap) > + return -EINVAL; > + if (vma->vm_pgoff) > + return -EINVAL; > + if (vma->vm_flags & VM_WRITE) > + return -EACCES; > + > + err =3D vop_vdev_inited(vdev); > + if (err) > + return err; >=20 > /* > * MMAP interface is as follows: > @@ -1057,58 +1052,38 @@ vop_query_offset(struct vop_vdev *vdev, > unsigned long offset, > * 0x1000 first vring > * 0x1000 + size of 1st vring second vring > * .... > + * > + * We manipulate vm_start/vm_end to trick dma_mmap_coherent > into > + * performing partial mappings, which is a bit of a hack, but safe > + * while we are under mmap_lock(). Eventually this needs to be > + * replaced by a proper DMA layer API. > */ > - if (!offset) { > - *pa =3D virt_to_phys(vpdev->hw_ops->get_dp(vpdev)); > - *size =3D MIC_DP_SIZE; > - return 0; > - } > + vma->vm_end =3D vma->vm_start + MIC_DP_SIZE; > + err =3D vdev->vpdev->hw_ops->dp_mmap(vdev->vpdev, vma); > + if (err) > + goto out; >=20 > for (i =3D 0; i < vdev->dd->num_vq; i++) { > struct vop_vringh *vvr =3D &vdev->vvr[i]; >=20 > - if (offset =3D=3D start) { > - *pa =3D virt_to_phys(vvr->vring.va); > - *size =3D vvr->vring.len; > - return 0; > - } > - start +=3D vvr->vring.len; > - } > - return -1; > -} > - > -/* > - * Maps the device page and virtio rings to user space for readonly acce= ss. > - */ > -static int vop_mmap(struct file *f, struct vm_area_struct *vma) -{ > - struct vop_vdev *vdev =3D f->private_data; > - unsigned long offset =3D vma->vm_pgoff << PAGE_SHIFT; > - unsigned long pa, size =3D vma->vm_end - vma->vm_start, size_rem =3D > size; > - int i, err; > + vma->vm_start =3D vma->vm_end; > + vma->vm_end +=3D vvr->vring.len; >=20 > - err =3D vop_vdev_inited(vdev); > - if (err) > - goto ret; > - if (vma->vm_flags & VM_WRITE) { > - err =3D -EACCES; > - goto ret; > - } > - while (size_rem) { > - i =3D vop_query_offset(vdev, offset, &size, &pa); > - if (i < 0) { > - err =3D -EINVAL; > - goto ret; > - } > - err =3D remap_pfn_range(vma, vma->vm_start + offset, > - pa >> PAGE_SHIFT, size, > - vma->vm_page_prot); > + err =3D -EINVAL; > + if (vma->vm_end > orig_end) > + goto out; > + err =3D dma_mmap_coherent(vop_dev(vdev), vma, vvr- > >vring.va, > + le64_to_cpu(vqconfig[i].address), > + vvr->vring.len); > if (err) > - goto ret; > - size_rem -=3D size; > - offset +=3D size; > + goto out; > } > -ret: > +out: > + /* > + * Restore the original vma parameters. > + */ > + vma->vm_start =3D orig_start; > + vma->vm_end =3D orig_end; > return err; > } >=20 > -- > 2.28.0