[SRU][F][G][PATCH 2/2] s390/pci: create links between PFs and VFs
frank.heimes at canonical.com
frank.heimes at canonical.com
Tue Jun 2 09:45:36 UTC 2020
From: Niklas Schnelle <schnelle at linux.ibm.com>
BugLink: https://bugs.launchpad.net/bugs/1879704
On s390 PCI Virtual Functions (VFs) are scanned by firmware and are made
available to Linux via the hot-plug interface. As such the common code
path of doing the scan directly using the parent Physical Function (PF)
is not used and fenced off with the no_vf_scan attribute.
Even if the partition created the VFs itself e.g. using the sriov_numvfs
attribute of a PF, the PF/VF links thus need to be established after the
fact. To do this when a VF is plugged we scan through all functions on
the same zbus and test whether they are the parent PF in which case we
establish the necessary links.
With these links established there is now no more need to fence off
pci_iov_remove_virtfn() for pdev->no_vf_scan as the common code now
works fine.
Signed-off-by: Niklas Schnelle <schnelle at linux.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas at google.com>
Reviewed-by: Pierre Morel <pmorel at linux.ibm.com>
[ schnelle: Link: https://lore.kernel.org/r/20200506154139.90609-3-schnelle@linux.ibm.com ]
Signed-off-by: Vasily Gorbik <gor at linux.ibm.com>
(cherry picked from commit e5794cf1a270d813a5b9373a6876487d4d154195)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
arch/s390/include/asm/pci.h | 3 +-
arch/s390/include/asm/pci_clp.h | 3 +-
arch/s390/pci/pci_bus.c | 72 ++++++++++++++++++++++++++++++++-
arch/s390/pci/pci_clp.c | 1 +
drivers/pci/iov.c | 3 --
5 files changed, 75 insertions(+), 7 deletions(-)
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 4bbd2c79ec4a..ea0daab3eb80 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -133,7 +133,8 @@ struct zpci_dev {
u8 port;
u8 rid_available : 1;
u8 has_hp_slot : 1;
- u8 reserved : 6;
+ u8 is_physfn : 1;
+ u8 reserved : 5;
unsigned int devfn; /* DEVFN part of the RID*/
struct mutex lock;
diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
index 4391ce82230f..641b7e8d0226 100644
--- a/arch/s390/include/asm/pci_clp.h
+++ b/arch/s390/include/asm/pci_clp.h
@@ -95,7 +95,8 @@ struct clp_rsp_query_pci {
u16 vfn; /* virtual fn number */
u16 : 3;
u16 rid_avail : 1;
- u16 : 2;
+ u16 is_physfn : 1;
+ u16 reserved1 : 1;
u16 mio_addr_avail : 1;
u16 util_str_avail : 1; /* utility string available? */
u16 pfgid : 8; /* pci function group id */
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index fdc36f948ab2..d5fa0130604d 100644
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -121,6 +121,64 @@ static struct zpci_bus *zpci_bus_alloc(int pchid)
return zbus;
}
+#ifdef CONFIG_PCI_IOV
+static int zpci_bus_link_virtfn(struct pci_dev *pdev,
+ struct pci_dev *virtfn, int vfid)
+{
+ int rc;
+
+ virtfn->physfn = pci_dev_get(pdev);
+ rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
+ if (rc) {
+ pci_dev_put(pdev);
+ virtfn->physfn = NULL;
+ return rc;
+ }
+ return 0;
+}
+
+static int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
+ struct pci_dev *virtfn, int vfn)
+{
+ int i, cand_devfn;
+ struct zpci_dev *zdev;
+ struct pci_dev *pdev;
+ int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
+ int rc = 0;
+
+ virtfn->is_virtfn = 1;
+ virtfn->multifunction = 0;
+ WARN_ON(vfid < 0);
+ /* If the parent PF for the given VF is also configured in the
+ * instance, it must be on the same zbus.
+ * We can then identify the parent PF by checking what
+ * devfn the VF would have if it belonged to that PF using the PF's
+ * stride and offset. Only if this candidate devfn matches the
+ * actual devfn will we link both functions.
+ */
+ for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
+ zdev = zbus->function[i];
+ if (zdev && zdev->is_physfn) {
+ pdev = pci_get_slot(zbus->bus, zdev->devfn);
+ cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
+ if (cand_devfn == virtfn->devfn) {
+ rc = zpci_bus_link_virtfn(pdev, virtfn, vfid);
+ break;
+ }
+ }
+ }
+ return rc;
+}
+#else
+static inline int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
+ struct pci_dev *virtfn, int vfn)
+{
+ virtfn->is_virtfn = 1;
+ virtfn->multifunction = 0;
+ return 0;
+}
+#endif
+
static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
{
struct pci_bus *bus;
@@ -151,10 +209,20 @@ static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
}
pdev = pci_scan_single_device(bus, zdev->devfn);
- if (pdev)
+ if (pdev) {
+ if (!zdev->is_physfn) {
+ rc = zpci_bus_setup_virtfn(zbus, pdev, zdev->vfn);
+ if (rc)
+ goto failed_with_pdev;
+ }
pci_bus_add_device(pdev);
-
+ }
return 0;
+
+failed_with_pdev:
+ pci_stop_and_remove_bus_device(pdev);
+ pci_dev_put(pdev);
+ return rc;
}
static void zpci_bus_add_devices(struct zpci_bus *zbus)
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index f7dfcd9f8b9e..e71133031f62 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -159,6 +159,7 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
zdev->uid = response->uid;
zdev->fmb_length = sizeof(u32) * response->fmb_len;
zdev->rid_available = response->rid_avail;
+ zdev->is_physfn = response->is_physfn;
if (!s390_pci_no_rid && zdev->rid_available)
zdev->devfn = response->rid & ZPCI_RID_MASK_DEVFN;
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9c778671db99..693c940c13b4 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -566,9 +566,6 @@ static void sriov_del_vfs(struct pci_dev *dev)
struct pci_sriov *iov = dev->sriov;
int i;
- if (dev->no_vf_scan)
- return;
-
for (i = 0; i < iov->num_VFs; i++)
pci_iov_remove_virtfn(dev, i);
}
--
2.25.1
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