... 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 <bhelgaas@xxxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
---
v1 -> v2:
* Rebase on latest + remove dependency on a non-upstream patch.
drivers/pci/iov.c | 16 ++++++++++++++++
drivers/pci/pci.h | 5 +++++
drivers/pci/probe.c | 42 ++++++++++++++++++++++++++++++++----------
3 files changed, 53 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 677924a..e1d2e3f 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -114,6 +114,19 @@ resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
}
+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->class);
+ pci_bus_read_config_word(bus, devfn, PCI_SUBSYSTEM_ID,
+ &dev->sriov->subsystem_device);
+ pci_bus_read_config_word(bus, devfn, PCI_SUBSYSTEM_VENDOR_ID,
+ &dev->sriov->subsystem_vendor);
+ pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &dev->sriov->hdr_type);
+}
+
int pci_iov_add_virtfn(struct pci_dev *dev, int id)
{
int i;
@@ -133,6 +146,9 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
if (!virtfn)
goto failed0;
+ if (id == 0)
+ pci_read_vf_config_common(bus, dev);
+
virtfn->devfn = pci_iov_virtfn_devfn(dev, id);
virtfn->vendor = dev->vendor;
virtfn->device = iov->vf_device;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fcd8191..346daa5 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -271,6 +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 */
+ u8 hdr_type; /* VF header type */
+ u32 class; /* VF device */
+ u16 device; /* VF device */
+ u16 subsystem_vendor; /* VF subsystem vendor */
+ u16 subsystem_device; /* VF subsystem device */
resource_size_t 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 ef53774..aeaa10a 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -180,6 +180,7 @@ 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;
@@ -199,9 +200,13 @@ 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->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.
@@ -241,9 +246,14 @@ 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->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);
@@ -332,6 +342,8 @@ 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->barsz[pos] == 0)
+ continue;
pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
}
@@ -1454,7 +1466,9 @@ 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->hdr_type;
+ else if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
return -EIO;
dev->sysdata = dev->bus->sysdata;
@@ -1477,7 +1491,10 @@ 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->class;
+ else
+ pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
dev->revision = class & 0xff;
dev->class = class >> 8; /* upper 3 bytes */
@@ -1517,8 +1534,13 @@ 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->subsystem_vendor;
+ dev->subsystem_device = dev->physfn->sriov->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
