On Wed, 2018-02-28 at 15:30 -0600, Bjorn Helgaas wrote:
> On Wed, Jan 17, 2018 at 06:44:23PM +0100, KarimAllah Ahmed wrote:
> >
> > ... to avoid reading them from the config space of all the PCI VFs. This is
> > specially a useful optimization when bringing up thousands of VFs.
> >
> > Cc: Bjorn Helgaas <bhelg...@google.com>
> > Cc: linux-...@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: KarimAllah Ahmed <karah...@amazon.de>
>
> What does this patch apply to? It doesn't apply to v4.16-rc1 (my
> "master" branch). I don't see anything in the history of
> drivers/pci/iov.c about pci_iov_wq_fn().
Ah, right! I had a few patches in my branch and I decided to only post
this one for now. The pci_iov_wq_fn was part of one of them.
Will shuffle the patches, rebase and repost.
Thanks.
>
> >
> > ---
> > drivers/pci/iov.c | 20 ++++++++++++++++++--
> > drivers/pci/pci.h | 6 +++++-
> > drivers/pci/probe.c | 42 ++++++++++++++++++++++++++++++++----------
> > 3 files changed, 55 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> > index 168328a..78e9595 100644
> > --- a/drivers/pci/iov.c
> > +++ b/drivers/pci/iov.c
> > @@ -129,7 +129,7 @@ resource_size_t pci_iov_resource_size(struct pci_dev
> > *dev, int resno)
> > if (!dev->is_physfn)
> > return 0;
> >
> > - return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
> > + return dev->sriov->vf_barsz[resno - PCI_IOV_RESOURCES];
> > }
> >
> > int batch_pci_iov_add_virtfn(struct pci_dev *dev, struct pci_bus **bus,
> > @@ -325,6 +325,20 @@ static void pci_iov_wq_fn(struct work_struct *work)
> > kfree(req);
> > }
> >
> > +static void pci_read_vf_config_common(struct pci_bus *bus,
> > + struct pci_dev *dev)
> > +{
> > + int devfn = pci_iov_virtfn_devfn(dev, 0);
> > +
> > + pci_bus_read_config_dword(bus, devfn, PCI_CLASS_REVISION,
> > + &dev->sriov->vf_class);
> > + pci_bus_read_config_word(bus, devfn, PCI_SUBSYSTEM_ID,
> > + &dev->sriov->vf_subsystem_device);
> > + pci_bus_read_config_word(bus, devfn, PCI_SUBSYSTEM_VENDOR_ID,
> > + &dev->sriov->vf_subsystem_vendor);
> > + pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE,
> > &dev->sriov->vf_hdr_type);
> > +}
> > +
> > static struct workqueue_struct *pci_iov_wq;
> >
> > static int __init init_pci_iov_wq(void)
> > @@ -361,6 +375,8 @@ static int enable_vfs(struct pci_dev *dev, int nr_vfs)
> > goto add_bus_fail;
> > }
> >
> > + pci_read_vf_config_common(bus[0], dev);
> > +
> > while (remaining_vfs > 0) {
> > bool ret;
> > struct pci_iov_wq_item *req;
> > @@ -617,7 +633,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
> > rc = -EIO;
> > goto failed;
> > }
> > - iov->barsz[i] = resource_size(res);
> > + iov->vf_barsz[i] = resource_size(res);
> > res->end = res->start + resource_size(res) * total - 1;
> > dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for
> > %d VFs)\n",
> > i, res, i, total);
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> > index f6b58b3..3264c9e 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -271,7 +271,11 @@ struct pci_sriov {
> > u16 driver_max_VFs; /* max num VFs driver supports */
> > struct pci_dev *dev; /* lowest numbered PF */
> > struct pci_dev *self; /* this PF */
> > - resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */
> > + u8 vf_hdr_type; /* VF header type */
> > + u32 vf_class; /* VF device */
> > + u16 vf_subsystem_vendor; /* VF subsystem vendor */
> > + u16 vf_subsystem_device; /* VF subsystem device */
> > + resource_size_t vf_barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */
> > bool drivers_autoprobe; /* auto probing of VFs by driver */
> > };
> >
> > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> > index 14e0ea1..65099d0 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -175,6 +175,7 @@ static inline unsigned long decode_bar(struct pci_dev
> > *dev, u32 bar)
> > int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
> > struct resource *res, unsigned int pos)
> > {
> > + int bar = res - dev->resource;
> > u32 l = 0, sz = 0, mask;
> > u64 l64, sz64, mask64;
> > u16 orig_cmd;
> > @@ -194,9 +195,13 @@ int __pci_read_base(struct pci_dev *dev, enum
> > pci_bar_type type,
> > res->name = pci_name(dev);
> >
> > pci_read_config_dword(dev, pos, &l);
> > - pci_write_config_dword(dev, pos, l | mask);
> > - pci_read_config_dword(dev, pos, &sz);
> > - pci_write_config_dword(dev, pos, l);
> > + if (dev->is_virtfn) {
> > + sz = dev->physfn->sriov->vf_barsz[bar] & 0xffffffff;
> > + } else {
> > + pci_write_config_dword(dev, pos, l | mask);
> > + pci_read_config_dword(dev, pos, &sz);
> > + pci_write_config_dword(dev, pos, l);
> > + }
> >
> > /*
> > * All bits set in sz means the device isn't working properly.
> > @@ -236,9 +241,14 @@ int __pci_read_base(struct pci_dev *dev, enum
> > pci_bar_type type,
> >
> > if (res->flags & IORESOURCE_MEM_64) {
> > pci_read_config_dword(dev, pos + 4, &l);
> > - pci_write_config_dword(dev, pos + 4, ~0);
> > - pci_read_config_dword(dev, pos + 4, &sz);
> > - pci_write_config_dword(dev, pos + 4, l);
> > +
> > + if (dev->is_virtfn) {
> > + sz = (dev->physfn->sriov->vf_barsz[bar] >> 32) &
> > 0xffffffff;
> > + } else {
> > + pci_write_config_dword(dev, pos + 4, ~0);
> > + pci_read_config_dword(dev, pos + 4, &sz);
> > + pci_write_config_dword(dev, pos + 4, l);
> > + }
> >
> > l64 |= ((u64)l << 32);
> > sz64 |= ((u64)sz << 32);
> > @@ -327,6 +337,8 @@ static void pci_read_bases(struct pci_dev *dev,
> > unsigned int howmany, int rom)
> > for (pos = 0; pos < howmany; pos++) {
> > struct resource *res = &dev->resource[pos];
> > reg = PCI_BASE_ADDRESS_0 + (pos << 2);
> > + if (dev->is_virtfn && dev->physfn->sriov->vf_barsz[pos] == 0)
> > + continue;
> > pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
> > }
> >
> > @@ -1444,7 +1456,9 @@ int pci_setup_device(struct pci_dev *dev)
> > struct pci_bus_region region;
> > struct resource *res;
> >
> > - if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
> > + if (dev->is_virtfn)
> > + hdr_type = dev->physfn->sriov->vf_hdr_type;
> > + else if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
> > return -EIO;
> >
> > dev->sysdata = dev->bus->sysdata;
> > @@ -1464,7 +1478,10 @@ int pci_setup_device(struct pci_dev *dev)
> > dev->bus->number, PCI_SLOT(dev->devfn),
> > PCI_FUNC(dev->devfn));
> >
> > - pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
> > + if (dev->is_virtfn)
> > + class = dev->physfn->sriov->vf_class;
> > + else
> > + pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
> > dev->revision = class & 0xff;
> > dev->class = class >> 8; /* upper 3 bytes */
> >
> > @@ -1503,8 +1520,13 @@ int pci_setup_device(struct pci_dev *dev)
> > goto bad;
> > pci_read_irq(dev);
> > pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
> > - pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID,
> > &dev->subsystem_vendor);
> > - pci_read_config_word(dev, PCI_SUBSYSTEM_ID,
> > &dev->subsystem_device);
> > + if (dev->is_virtfn) {
> > + dev->subsystem_vendor =
> > dev->physfn->sriov->vf_subsystem_vendor;
> > + dev->subsystem_device =
> > dev->physfn->sriov->vf_subsystem_device;
> > + } else {
> > + pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID,
> > &dev->subsystem_vendor);
> > + pci_read_config_word(dev, PCI_SUBSYSTEM_ID,
> > &dev->subsystem_device);
> > + }
> >
> > /*
> > * Do the ugly legacy mode stuff here rather than broken chip
> > --
> > 2.7.4
> >
>
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