[PATCH 1/4] perf/dwc_pcie: Fix registration issue in multi PCIe controller instances

From: Krishna chaitanya chundru
Date: Wed Jul 31 2024 - 00:25:09 EST


When there are multiple of instances of PCIe controllers, registration
to perf driver fails with this error.
sysfs: cannot create duplicate filename '/devices/platform/dwc_pcie_pmu.0'
CPU: 0 PID: 166 Comm: modprobe Not tainted 6.10.0-rc2-next-20240607-dirty
Hardware name: Qualcomm SA8775P Ride (DT)
Call trace:
dump_backtrace.part.8+0x98/0xf0
show_stack+0x14/0x1c
dump_stack_lvl+0x74/0x88
dump_stack+0x14/0x1c
sysfs_warn_dup+0x60/0x78
sysfs_create_dir_ns+0xe8/0x100
kobject_add_internal+0x94/0x224
kobject_add+0xa8/0x118
device_add+0x298/0x7b4
platform_device_add+0x1a0/0x228
platform_device_register_full+0x11c/0x148
dwc_pcie_register_dev+0x74/0xf0 [dwc_pcie_pmu]
dwc_pcie_pmu_init+0x7c/0x1000 [dwc_pcie_pmu]
do_one_initcall+0x58/0x1c0
do_init_module+0x58/0x208
load_module+0x1804/0x188c
__do_sys_init_module+0x18c/0x1f0
__arm64_sys_init_module+0x14/0x1c
invoke_syscall+0x40/0xf8
el0_svc_common.constprop.1+0x70/0xf4
do_el0_svc+0x18/0x20
el0_svc+0x28/0xb0
el0t_64_sync_handler+0x9c/0xc0
el0t_64_sync+0x160/0x164
kobject: kobject_add_internal failed for dwc_pcie_pmu.0 with -EEXIST,
don't try to register things with the same name in the same directory.

This is because of having same bdf value for devices under two different
controllers.

Update the logic to use sbdf which is a unique number in case of
multi instance also.

Fixes: af9597adc2f1 ("drivers/perf: add DesignWare PCIe PMU driver")
Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
drivers/perf/dwc_pcie_pmu.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
index c5e328f23841..c115348b8d53 100644
--- a/drivers/perf/dwc_pcie_pmu.c
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -556,10 +556,10 @@ static int dwc_pcie_register_dev(struct pci_dev *pdev)
{
struct platform_device *plat_dev;
struct dwc_pcie_dev_info *dev_info;
- u32 bdf;
+ u32 sbdf;

- bdf = PCI_DEVID(pdev->bus->number, pdev->devfn);
- plat_dev = platform_device_register_data(NULL, "dwc_pcie_pmu", bdf,
+ sbdf = (pci_domain_nr(pdev->bus) << 16) | PCI_DEVID(pdev->bus->number, pdev->devfn);
+ plat_dev = platform_device_register_data(NULL, "dwc_pcie_pmu", sbdf,
pdev, sizeof(*pdev));

if (IS_ERR(plat_dev))
@@ -611,15 +611,15 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
struct pci_dev *pdev = plat_dev->dev.platform_data;
struct dwc_pcie_pmu *pcie_pmu;
char *name;
- u32 bdf, val;
+ u32 sbdf, val;
u16 vsec;
int ret;

vsec = pci_find_vsec_capability(pdev, pdev->vendor,
DWC_PCIE_VSEC_RAS_DES_ID);
pci_read_config_dword(pdev, vsec + PCI_VNDR_HEADER, &val);
- bdf = PCI_DEVID(pdev->bus->number, pdev->devfn);
- name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", bdf);
+ sbdf = (pci_domain_nr(pdev->bus) << 16) | PCI_DEVID(pdev->bus->number, pdev->devfn);
+ name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
if (!name)
return -ENOMEM;

@@ -650,7 +650,7 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
ret = cpuhp_state_add_instance(dwc_pcie_pmu_hp_state,
&pcie_pmu->cpuhp_node);
if (ret) {
- pci_err(pdev, "Error %d registering hotplug @%x\n", ret, bdf);
+ pci_err(pdev, "Error %d registering hotplug @%x\n", ret, sbdf);
return ret;
}

@@ -663,7 +663,7 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)

ret = perf_pmu_register(&pcie_pmu->pmu, name, -1);
if (ret) {
- pci_err(pdev, "Error %d registering PMU @%x\n", ret, bdf);
+ pci_err(pdev, "Error %d registering PMU @%x\n", ret, sbdf);
return ret;
}
ret = devm_add_action_or_reset(&plat_dev->dev, dwc_pcie_unregister_pmu,

--
2.34.1