On Tue, 8 Aug 2023 14:27:13 -0500
Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> When registering an acpiphp slot, log the slot name in the same style as
> pciehp and include the PCI bus/device and whether a device is present or
> the slot is empty.
>
> When handling an ACPI notification, log the PCI bus/device and notification
> type.
>
> Sample dmesg log diff:
>
> ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
> - acpiphp: Slot [3] registered
> - acpiphp: Slot [4] registered
> PCI host bridge to bus 0000:00
> pci 0000:00:03.0: [8086:100e] type 00 class 0x020000
> <ACPI Device Check notification>
Having ACPI node name/path here that received notification would be helpfull
> pci 0000:00:04.0: [8086:100e] type 00 class 0x020000
>
> ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
> + acpiphp: pci 0000:00:03 Slot(3) registered (enabled)
> + acpiphp: pci 0000:00:04 Slot(4) registered (empty)
> PCI host bridge to bus 0000:00
> pci 0000:00:03.0: [8086:100e] type 00 class 0x020000
> <ACPI Device Check notification>
> + acpiphp: pci 0000:00:04 Slot(4) Device Check
> pci 0000:00:04.0: [8086:100e] type 00 class 0x020000
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/hotplug/acpiphp_core.c | 4 ----
> drivers/pci/hotplug/acpiphp_glue.c | 23 +++++++++++++++++++++--
> 2 files changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/hotplug/acpiphp_core.c b/drivers/pci/hotplug/acpiphp_core.c
> index c02257f4b61c..19d47607d009 100644
> --- a/drivers/pci/hotplug/acpiphp_core.c
> +++ b/drivers/pci/hotplug/acpiphp_core.c
> @@ -282,8 +282,6 @@ int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
> goto error_slot;
> }
>
> - pr_info("Slot [%s] registered\n", slot_name(slot));
> -
> return 0;
> error_slot:
> kfree(slot);
> @@ -296,8 +294,6 @@ void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
> {
> struct slot *slot = acpiphp_slot->slot;
>
> - pr_info("Slot [%s] unregistered\n", slot_name(slot));
> -
> pci_hp_deregister(&slot->hotplug_slot);
> kfree(slot);
> }
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 328d1e416014..eeca2753a5c7 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -25,7 +25,7 @@
> * bus. It loses the refcount when the driver unloads.
> */
>
> -#define pr_fmt(fmt) "acpiphp_glue: " fmt
> +#define pr_fmt(fmt) "acpiphp: " fmt
>
> #include <linux/module.h>
>
> @@ -333,6 +333,12 @@ static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data,
> &val, 60*1000))
> slot->flags |= SLOT_ENABLED;
>
> + if (slot->slot)
> + pr_info("pci %04x:%02x:%02x Slot(%s) registered (%s)\n",
> + pci_domain_nr(slot->bus), slot->bus->number,
> + slot->device, slot_name(slot->slot),
> + slot->flags & SLOT_ENABLED ? "enabled" : "empty");
> +
> return AE_OK;
> }
>
> @@ -351,8 +357,13 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
> acpi_unlock_hp_context();
> }
> slot->flags |= SLOT_IS_GOING_AWAY;
> - if (slot->slot)
> + if (slot->slot) {
> + pr_info("pci %04x:%02x:%02x Slot(%s) unregistered\n",
> + pci_domain_nr(slot->bus), slot->bus->number,
> + slot->device, slot_name(slot->slot));
> +
> acpiphp_unregister_hotplug_slot(slot);
> + }
> }
>
> mutex_lock(&bridge_mutex);
> @@ -793,6 +804,14 @@ static void hotplug_event(u32 type, struct acpiphp_context *context)
>
> pci_lock_rescan_remove();
>
> + pr_info("pci %04x:%02x:%02x Slot(%s) %s\n",
> + pci_domain_nr(slot->bus), slot->bus->number,
> + slot->device, slot_name(slot->slot),
I had similar issue with logging patches that I've asked Woody to run.
it crashes here with buscheck on non existing device
Call Trace:
<TASK>
? __die_body+0x19/0x60
? page_fault_oops+0x158/0x430
? fixup_exception+0x21/0x330
? exc_page_fault+0x6b/0x150
? asm_exc_page_fault+0x26/0x30
? acpiphp_hotplug_notify+0x13d/0x2f0
? __pfx_acpiphp_hotplug_notify+0x10/0x10
acpi_device_hotplug+0xc2/0x4f0
acpi_hotplug_work_fn+0x19/0x30
process_one_work+0x1f8/0x3e0
worker_thread+0x29/0x3b0
? __pfx_worker_thread+0x10/0x10
kthread+0xf2/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2f/0x40
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0
(gdb) p *slot
$2 = {node = {next = 0xffff8881003287c0, prev = 0xffff888100887730}, bus = 0xffff8881003de800,
funcs = {next = 0xffff8881008877b0, prev = 0xffff888100887a50}, slot = 0x0 <fixed_percpu_data>,
^^^ likely culprit
device = 0x0, flags = 0x1}
reproducer hack: https://gitlab.com/imammedo/qemu/-/tree/acpiphp_buscheck_on_missing_device?ref_type=heads
./qemu-system-x86_64 -M q35 -cpu host -smp 4 -enable-kvm -m 6G -kernel ~/builds/linux-2.6/arch/x86/boot/bzImage -append 'nokaslr root=/dev/sda1 console=ttyS0' -snapshot rhel9.img -device pcie-root-port,id=rp1,bus=pcie.0,chassis=0,addr=8 -monitor stdio -serial file:/tmp/s -s
then once booted to trigger buscheck issue at monitor prompt:
(qemu) device_add e1000e,bus=rp1
> + type == ACPI_NOTIFY_BUS_CHECK ? "Bus Check" :
> + type == ACPI_NOTIFY_DEVICE_CHECK ? "Device Check" :
> + type == ACPI_NOTIFY_EJECT_REQUEST ? "Eject Request" :
> + "Notification");
> +
> switch (type) {
> case ACPI_NOTIFY_BUS_CHECK:
> /* bus re-enumerate */
