[SRU][J][PATCH 03/17] s390/pci: Use topology ID for multi-function devices
Massimiliano Pellizzer
massimiliano.pellizzer at canonical.com
Thu Aug 28 09:30:55 UTC 2025
From: Niklas Schnelle <schnelle at linux.ibm.com>
BugLink: https://bugs.launchpad.net/bugs/2119650
The newly introduced topology ID (TID) field in the CLP Query PCI
Function explicitly identifies groups of PCI functions whose RIDs belong
to the same (sub-)topology. When available use the TID instead of the
PCHID to match zPCI busses/domains for multi-function devices. Note that
currently only a single PCI bus per TID is supported. This change is
required because in future machines the PCHID will not identify a PCI
card but a specific port in the case of some multi-port NICs while from
a PCI point of view the entire card is a subtopology.
Reviewed-by: Gerd Bayer <gbayer at linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle at linux.ibm.com>
Signed-off-by: Heiko Carstens <hca at linux.ibm.com>
(cherry picked from commit 126034faaac5f356822c4a9bebfa75664da11056)
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
arch/s390/include/asm/pci.h | 9 ++++++---
arch/s390/include/asm/pci_clp.h | 8 +++++---
arch/s390/pci/pci_bus.c | 17 ++++++++++-------
arch/s390/pci/pci_clp.c | 3 +++
4 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index da0d5f7475eb..889b2569de08 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -108,9 +108,10 @@ struct zpci_bus {
struct list_head resources;
struct list_head bus_next;
struct resource bus_resource;
- int pchid;
+ int topo; /* TID if topo_is_tid, PCHID otherwise */
int domain_nr;
- bool multifunction;
+ u8 multifunction : 1;
+ u8 topo_is_tid : 1;
enum pci_bus_speed max_bus_speed;
};
@@ -130,6 +131,7 @@ struct zpci_dev {
u16 pchid; /* physical channel ID */
u16 maxstbl; /* Maximum store block size */
u16 rid; /* RID as supplied by firmware */
+ u16 tid; /* Topology for which RID is valid */
u8 pfgid; /* function group ID */
u8 pft; /* pci function type */
u8 port;
@@ -140,7 +142,8 @@ struct zpci_dev {
u8 is_physfn : 1;
u8 util_str_avail : 1;
u8 irqs_registered : 1;
- u8 reserved : 2;
+ u8 tid_avail : 1;
+ u8 reserved : 1;
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 d6189ed14f84..883aba330fea 100644
--- a/arch/s390/include/asm/pci_clp.h
+++ b/arch/s390/include/asm/pci_clp.h
@@ -107,7 +107,8 @@ struct clp_req_query_pci {
struct clp_rsp_query_pci {
struct clp_rsp_hdr hdr;
u16 vfn; /* virtual fn number */
- u16 : 3;
+ u16 : 2;
+ u16 tid_avail : 1;
u16 rid_avail : 1;
u16 is_physfn : 1;
u16 reserved1 : 1;
@@ -127,8 +128,9 @@ struct clp_rsp_query_pci {
u64 edma; /* end dma as */
#define ZPCI_RID_MASK_DEVFN 0x00ff
u16 rid; /* BUS/DEVFN PCI address */
- u16 reserved0;
- u32 reserved[10];
+ u32 reserved0;
+ u16 tid;
+ u32 reserved[9];
u32 uid; /* user defined id */
u8 util_str[CLP_UTIL_STR_LEN]; /* utility string */
u32 reserved2[16];
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index cc7e5b22ccfb..fb6da86a8a84 100644
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -245,13 +245,13 @@ static void zpci_bus_put(struct zpci_bus *zbus)
kref_put(&zbus->kref, zpci_bus_release);
}
-static struct zpci_bus *zpci_bus_get(int pchid)
+static struct zpci_bus *zpci_bus_get(int topo, bool topo_is_tid)
{
struct zpci_bus *zbus;
mutex_lock(&zbus_list_lock);
list_for_each_entry(zbus, &zbus_list, bus_next) {
- if (pchid == zbus->pchid) {
+ if (topo_is_tid == zbus->topo_is_tid && topo == zbus->topo) {
kref_get(&zbus->kref);
goto out_unlock;
}
@@ -262,7 +262,7 @@ static struct zpci_bus *zpci_bus_get(int pchid)
return zbus;
}
-static struct zpci_bus *zpci_bus_alloc(int pchid)
+static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid)
{
struct zpci_bus *zbus;
@@ -270,7 +270,8 @@ static struct zpci_bus *zpci_bus_alloc(int pchid)
if (!zbus)
return NULL;
- zbus->pchid = pchid;
+ zbus->topo = topo;
+ zbus->topo_is_tid = topo_is_tid;
INIT_LIST_HEAD(&zbus->bus_next);
mutex_lock(&zbus_list_lock);
list_add_tail(&zbus->bus_next, &zbus_list);
@@ -377,8 +378,9 @@ static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
{
+ bool topo_is_tid = zdev->tid_avail;
struct zpci_bus *zbus = NULL;
- int rc = -EBADF;
+ int topo, rc = -EBADF;
if (zpci_nb_devices == ZPCI_NR_DEVICES) {
pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
@@ -389,11 +391,12 @@ int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
return -EINVAL;
+ topo = topo_is_tid ? zdev->tid : zdev->pchid;
if (!s390_pci_no_rid && zdev->rid_available)
- zbus = zpci_bus_get(zdev->pchid);
+ zbus = zpci_bus_get(topo, topo_is_tid);
if (!zbus) {
- zbus = zpci_bus_alloc(zdev->pchid);
+ zbus = zpci_bus_alloc(topo, topo_is_tid);
if (!zbus)
return -ENOMEM;
}
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 3f26d8d8c78a..0f4df0a8eb04 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -169,6 +169,9 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
zdev->rid = response->rid;
if (!s390_pci_no_rid && zdev->rid_available)
zdev->devfn = response->rid & ZPCI_RID_MASK_DEVFN;
+ zdev->tid_avail = response->tid_avail;
+ if (zdev->tid_avail)
+ zdev->tid = response->tid;
memcpy(zdev->pfip, response->pfip, sizeof(zdev->pfip));
if (response->util_str_avail) {
--
2.48.1
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