Jason Wang
2023-Mar-15 07:05 UTC
[PATCH RFC v2 virtio 3/7] pds_vdpa: virtio bar setup for vdpa
On Thu, Mar 9, 2023 at 9:31?AM Shannon Nelson <shannon.nelson at amd.com> wrote:> > The PDS vDPA device has a virtio BAR for describing itself, and > the pds_vdpa driver needs to access it. Here we copy liberally > from the existing drivers/virtio/virtio_pci_modern_dev.c as it > has what we need, but we need to modify it so that it can work > with our device id and so we can use our own DMA mask.By passing a pointer to a customized id probing routine to vp_modern_probe()? Thanks> > We suspect there is room for discussion here about making the > existing code a little more flexible, but we thought we'd at > least start the discussion here. > > Signed-off-by: Shannon Nelson <shannon.nelson at amd.com> > --- > drivers/vdpa/pds/Makefile | 1 + > drivers/vdpa/pds/aux_drv.c | 14 ++ > drivers/vdpa/pds/aux_drv.h | 1 + > drivers/vdpa/pds/debugfs.c | 1 + > drivers/vdpa/pds/vdpa_dev.c | 1 + > drivers/vdpa/pds/virtio_pci.c | 281 ++++++++++++++++++++++++++++++++++ > drivers/vdpa/pds/virtio_pci.h | 8 + > 7 files changed, 307 insertions(+) > create mode 100644 drivers/vdpa/pds/virtio_pci.c > create mode 100644 drivers/vdpa/pds/virtio_pci.h > > diff --git a/drivers/vdpa/pds/Makefile b/drivers/vdpa/pds/Makefile > index 13b50394ec64..ca2efa8c6eb5 100644 > --- a/drivers/vdpa/pds/Makefile > +++ b/drivers/vdpa/pds/Makefile > @@ -4,6 +4,7 @@ > obj-$(CONFIG_PDS_VDPA) := pds_vdpa.o > > pds_vdpa-y := aux_drv.o \ > + virtio_pci.o \ > vdpa_dev.o > > pds_vdpa-$(CONFIG_DEBUG_FS) += debugfs.o > diff --git a/drivers/vdpa/pds/aux_drv.c b/drivers/vdpa/pds/aux_drv.c > index 63e40ae68211..28158d0d98a5 100644 > --- a/drivers/vdpa/pds/aux_drv.c > +++ b/drivers/vdpa/pds/aux_drv.c > @@ -4,6 +4,7 @@ > #include <linux/auxiliary_bus.h> > #include <linux/pci.h> > #include <linux/vdpa.h> > +#include <linux/virtio_pci_modern.h> > > #include <linux/pds/pds_core.h> > #include <linux/pds/pds_auxbus.h> > @@ -12,6 +13,7 @@ > #include "aux_drv.h" > #include "debugfs.h" > #include "vdpa_dev.h" > +#include "virtio_pci.h" > > static const struct auxiliary_device_id pds_vdpa_id_table[] = { > { .name = PDS_VDPA_DEV_NAME, }, > @@ -49,8 +51,19 @@ static int pds_vdpa_probe(struct auxiliary_device *aux_dev, > if (err) > goto err_aux_unreg; > > + /* Find the virtio configuration */ > + vdpa_aux->vd_mdev.pci_dev = padev->vf->pdev; > + err = pds_vdpa_probe_virtio(&vdpa_aux->vd_mdev); > + if (err) { > + dev_err(dev, "Unable to probe for virtio configuration: %pe\n", > + ERR_PTR(err)); > + goto err_free_mgmt_info; > + } > + > return 0; > > +err_free_mgmt_info: > + pci_free_irq_vectors(padev->vf->pdev); > err_aux_unreg: > padev->ops->unregister_client(padev); > err_free_mem: > @@ -65,6 +78,7 @@ static void pds_vdpa_remove(struct auxiliary_device *aux_dev) > struct pds_vdpa_aux *vdpa_aux = auxiliary_get_drvdata(aux_dev); > struct device *dev = &aux_dev->dev; > > + pds_vdpa_remove_virtio(&vdpa_aux->vd_mdev); > pci_free_irq_vectors(vdpa_aux->padev->vf->pdev); > > vdpa_aux->padev->ops->unregister_client(vdpa_aux->padev); > diff --git a/drivers/vdpa/pds/aux_drv.h b/drivers/vdpa/pds/aux_drv.h > index 94ba7abcaa43..87ac3c01c476 100644 > --- a/drivers/vdpa/pds/aux_drv.h > +++ b/drivers/vdpa/pds/aux_drv.h > @@ -16,6 +16,7 @@ struct pds_vdpa_aux { > > int vf_id; > struct dentry *dentry; > + struct virtio_pci_modern_device vd_mdev; > > int nintrs; > }; > diff --git a/drivers/vdpa/pds/debugfs.c b/drivers/vdpa/pds/debugfs.c > index 7b7e90fd6578..aa5e9677fe74 100644 > --- a/drivers/vdpa/pds/debugfs.c > +++ b/drivers/vdpa/pds/debugfs.c > @@ -1,6 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0-only > /* Copyright(c) 2023 Advanced Micro Devices, Inc */ > > +#include <linux/virtio_pci_modern.h> > #include <linux/vdpa.h> > > #include <linux/pds/pds_core.h> > diff --git a/drivers/vdpa/pds/vdpa_dev.c b/drivers/vdpa/pds/vdpa_dev.c > index bd840688503c..15d623297203 100644 > --- a/drivers/vdpa/pds/vdpa_dev.c > +++ b/drivers/vdpa/pds/vdpa_dev.c > @@ -4,6 +4,7 @@ > #include <linux/pci.h> > #include <linux/vdpa.h> > #include <uapi/linux/vdpa.h> > +#include <linux/virtio_pci_modern.h> > > #include <linux/pds/pds_core.h> > #include <linux/pds/pds_adminq.h> > diff --git a/drivers/vdpa/pds/virtio_pci.c b/drivers/vdpa/pds/virtio_pci.c > new file mode 100644 > index 000000000000..cb879619dac3 > --- /dev/null > +++ b/drivers/vdpa/pds/virtio_pci.c > @@ -0,0 +1,281 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > + > +/* > + * adapted from drivers/virtio/virtio_pci_modern_dev.c, v6.0-rc1 > + */ > + > +#include <linux/virtio_pci_modern.h> > +#include <linux/pci.h> > + > +#include "virtio_pci.h" > + > +/* > + * pds_vdpa_map_capability - map a part of virtio pci capability > + * @mdev: the modern virtio-pci device > + * @off: offset of the capability > + * @minlen: minimal length of the capability > + * @align: align requirement > + * @start: start from the capability > + * @size: map size > + * @len: the length that is actually mapped > + * @pa: physical address of the capability > + * > + * Returns the io address of for the part of the capability > + */ > +static void __iomem * > +pds_vdpa_map_capability(struct virtio_pci_modern_device *mdev, int off, > + size_t minlen, u32 align, u32 start, u32 size, > + size_t *len, resource_size_t *pa) > +{ > + struct pci_dev *dev = mdev->pci_dev; > + u8 bar; > + u32 offset, length; > + void __iomem *p; > + > + pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, > + bar), > + &bar); > + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset), > + &offset); > + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length), > + &length); > + > + /* Check if the BAR may have changed since we requested the region. */ > + if (bar >= PCI_STD_NUM_BARS || !(mdev->modern_bars & (1 << bar))) { > + dev_err(&dev->dev, > + "virtio_pci: bar unexpectedly changed to %u\n", bar); > + return NULL; > + } > + > + if (length <= start) { > + dev_err(&dev->dev, > + "virtio_pci: bad capability len %u (>%u expected)\n", > + length, start); > + return NULL; > + } > + > + if (length - start < minlen) { > + dev_err(&dev->dev, > + "virtio_pci: bad capability len %u (>=%zu expected)\n", > + length, minlen); > + return NULL; > + } > + > + length -= start; > + > + if (start + offset < offset) { > + dev_err(&dev->dev, > + "virtio_pci: map wrap-around %u+%u\n", > + start, offset); > + return NULL; > + } > + > + offset += start; > + > + if (offset & (align - 1)) { > + dev_err(&dev->dev, > + "virtio_pci: offset %u not aligned to %u\n", > + offset, align); > + return NULL; > + } > + > + if (length > size) > + length = size; > + > + if (len) > + *len = length; > + > + if (minlen + offset < minlen || > + minlen + offset > pci_resource_len(dev, bar)) { > + dev_err(&dev->dev, > + "virtio_pci: map virtio %zu@%u out of range on bar %i length %lu\n", > + minlen, offset, > + bar, (unsigned long)pci_resource_len(dev, bar)); > + return NULL; > + } > + > + p = pci_iomap_range(dev, bar, offset, length); > + if (!p) > + dev_err(&dev->dev, > + "virtio_pci: unable to map virtio %u@%u on bar %i\n", > + length, offset, bar); > + else if (pa) > + *pa = pci_resource_start(dev, bar) + offset; > + > + return p; > +} > + > +/** > + * virtio_pci_find_capability - walk capabilities to find device info. > + * @dev: the pci device > + * @cfg_type: the VIRTIO_PCI_CAP_* value we seek > + * @ioresource_types: IORESOURCE_MEM and/or IORESOURCE_IO. > + * @bars: the bitmask of BARs > + * > + * Returns offset of the capability, or 0. > + */ > +static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type, > + u32 ioresource_types, int *bars) > +{ > + int pos; > + > + for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); > + pos > 0; > + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { > + u8 type, bar; > + > + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, > + cfg_type), > + &type); > + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, > + bar), > + &bar); > + > + /* Ignore structures with reserved BAR values */ > + if (bar >= PCI_STD_NUM_BARS) > + continue; > + > + if (type == cfg_type) { > + if (pci_resource_len(dev, bar) && > + pci_resource_flags(dev, bar) & ioresource_types) { > + *bars |= (1 << bar); > + return pos; > + } > + } > + } > + return 0; > +} > + > +/* > + * pds_vdpa_probe_virtio: probe the modern virtio pci device, note that the > + * caller is required to enable PCI device before calling this function. > + * @mdev: the modern virtio-pci device > + * > + * Return 0 on succeed otherwise fail > + */ > +int pds_vdpa_probe_virtio(struct virtio_pci_modern_device *mdev) > +{ > + struct pci_dev *pci_dev = mdev->pci_dev; > + int err, common, isr, notify, device; > + u32 notify_length; > + u32 notify_offset; > + > + /* check for a common config: if not, use legacy mode (bar 0). */ > + common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG, > + IORESOURCE_IO | IORESOURCE_MEM, > + &mdev->modern_bars); > + if (!common) { > + dev_info(&pci_dev->dev, > + "virtio_pci: missing common config\n"); > + return -ENODEV; > + } > + > + /* If common is there, these should be too... */ > + isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG, > + IORESOURCE_IO | IORESOURCE_MEM, > + &mdev->modern_bars); > + notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG, > + IORESOURCE_IO | IORESOURCE_MEM, > + &mdev->modern_bars); > + if (!isr || !notify) { > + dev_err(&pci_dev->dev, > + "virtio_pci: missing capabilities %i/%i/%i\n", > + common, isr, notify); > + return -EINVAL; > + } > + > + /* Device capability is only mandatory for devices that have > + * device-specific configuration. > + */ > + device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG, > + IORESOURCE_IO | IORESOURCE_MEM, > + &mdev->modern_bars); > + > + err = pci_request_selected_regions(pci_dev, mdev->modern_bars, > + "virtio-pci-modern"); > + if (err) > + return err; > + > + err = -EINVAL; > + mdev->common = pds_vdpa_map_capability(mdev, common, > + sizeof(struct virtio_pci_common_cfg), > + 4, 0, > + sizeof(struct virtio_pci_common_cfg), > + NULL, NULL); > + if (!mdev->common) > + goto err_map_common; > + mdev->isr = pds_vdpa_map_capability(mdev, isr, sizeof(u8), 1, > + 0, 1, NULL, NULL); > + if (!mdev->isr) > + goto err_map_isr; > + > + /* Read notify_off_multiplier from config space. */ > + pci_read_config_dword(pci_dev, > + notify + offsetof(struct virtio_pci_notify_cap, > + notify_off_multiplier), > + &mdev->notify_offset_multiplier); > + /* Read notify length and offset from config space. */ > + pci_read_config_dword(pci_dev, > + notify + offsetof(struct virtio_pci_notify_cap, > + cap.length), > + ¬ify_length); > + > + pci_read_config_dword(pci_dev, > + notify + offsetof(struct virtio_pci_notify_cap, > + cap.offset), > + ¬ify_offset); > + > + /* We don't know how many VQs we'll map, ahead of the time. > + * If notify length is small, map it all now. > + * Otherwise, map each VQ individually later. > + */ > + if ((u64)notify_length + (notify_offset % PAGE_SIZE) <= PAGE_SIZE) { > + mdev->notify_base = pds_vdpa_map_capability(mdev, notify, > + 2, 2, > + 0, notify_length, > + &mdev->notify_len, > + &mdev->notify_pa); > + if (!mdev->notify_base) > + goto err_map_notify; > + } else { > + mdev->notify_map_cap = notify; > + } > + > + /* Again, we don't know how much we should map, but PAGE_SIZE > + * is more than enough for all existing devices. > + */ > + if (device) { > + mdev->device = pds_vdpa_map_capability(mdev, device, 0, 4, > + 0, PAGE_SIZE, > + &mdev->device_len, > + NULL); > + if (!mdev->device) > + goto err_map_device; > + } > + > + return 0; > + > +err_map_device: > + if (mdev->notify_base) > + pci_iounmap(pci_dev, mdev->notify_base); > +err_map_notify: > + pci_iounmap(pci_dev, mdev->isr); > +err_map_isr: > + pci_iounmap(pci_dev, mdev->common); > +err_map_common: > + pci_release_selected_regions(pci_dev, mdev->modern_bars); > + return err; > +} > + > +void pds_vdpa_remove_virtio(struct virtio_pci_modern_device *mdev) > +{ > + struct pci_dev *pci_dev = mdev->pci_dev; > + > + if (mdev->device) > + pci_iounmap(pci_dev, mdev->device); > + if (mdev->notify_base) > + pci_iounmap(pci_dev, mdev->notify_base); > + pci_iounmap(pci_dev, mdev->isr); > + pci_iounmap(pci_dev, mdev->common); > + pci_release_selected_regions(pci_dev, mdev->modern_bars); > +} > diff --git a/drivers/vdpa/pds/virtio_pci.h b/drivers/vdpa/pds/virtio_pci.h > new file mode 100644 > index 000000000000..f017cfa1173c > --- /dev/null > +++ b/drivers/vdpa/pds/virtio_pci.h > @@ -0,0 +1,8 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* Copyright(c) 2023 Advanced Micro Devices, Inc */ > + > +#ifndef _PDS_VIRTIO_PCI_H_ > +#define _PDS_VIRTIO_PCI_H_ > +int pds_vdpa_probe_virtio(struct virtio_pci_modern_device *mdev); > +void pds_vdpa_remove_virtio(struct virtio_pci_modern_device *mdev); > +#endif /* _PDS_VIRTIO_PCI_H_ */ > -- > 2.17.1 >