Re: [PATCH v3] ACPI: PCI: check if the root io space is page aligned

[Miao Wang <shankerwangmiao@gmail.com>]

> It seems that there is no reply from linux-mm about this. I believe even if
> there might be a better place for the mm subsystem to check the alignment,
> it is still necessary to do the check here, because details about which ACPI
> entry is causing the problem is only available here. If in the future, we would
> developed another better place to do the alignment check, we may refactor the
> code here.

Hi, all

Ping on this patch.

> 
>>>> 
>>>>> Signed-off-by: Miao Wang <shankerwangmiao@gmail.com>
>>>>> ---
>>>>> Changes in v3:
>>>>> - Adjust code formatting.
>>>>> - Reword the commit message for further description of the possible reason
>>>>> leading to misaligned IO resource addresses.
>>>>> - Link to v2: https://lore.kernel.org/r/20240814-check_pci_probe_res-v2-1-a03c8c9b498b@gmail.com
>>>>> 
>>>>> Changes in v2:
>>>>> - Sorry for posting out the draft version in V1, fixed a silly compiling issue.
>>>>> - Link to v1: https://lore.kernel.org/r/20240814-check_pci_probe_res-v1-1-122ee07821ab@gmail.com
>>>>> ---
>>>>> drivers/acpi/pci_root.c | 14 +++++++++++---
>>>>> 1 file changed, 11 insertions(+), 3 deletions(-)
>>>>> 
>>>>> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
>>>>> index d0bfb3706801..a425e93024f2 100644
>>>>> --- a/drivers/acpi/pci_root.c
>>>>> +++ b/drivers/acpi/pci_root.c
>>>>> @@ -858,7 +858,7 @@ static void acpi_pci_root_validate_resources(struct device *dev,
>>>>> }
>>>>> }
>>>>> 
>>>>> -static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
>>>>> +static void acpi_pci_root_remap_iospace(struct acpi_device *device,
>>>>> struct resource_entry *entry)
>>>>> {
>>>>> #ifdef PCI_IOBASE
>>>>> @@ -868,7 +868,15 @@ static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
>>>>> resource_size_t length = resource_size(res);
>>>>> unsigned long port;
>>>>> 
>>>>> - if (pci_register_io_range(fwnode, cpu_addr, length))
>>>>> + if (!PAGE_ALIGNED(cpu_addr) || !PAGE_ALIGNED(length) ||
>>>>> +     !PAGE_ALIGNED(pci_addr)) {
>>>>> + dev_err(&device->dev,
>>>>> + FW_BUG "I/O resource %pR or its offset %pa is not page aligned\n",
>>>>> + res, &entry->offset);
>>>>> + goto err;
>>>>> + }
>>>>> +
>>>>> + if (pci_register_io_range(&device->fwnode, cpu_addr, length))
>>>>> goto err;
>>>> 
>>>> This change verifies alignment for the ACPI case that leads to the
>>>> pci_remap_iospace() -> vmap_page_range() -> vmap_pte_range() path, but 
>>>> there are others even in drivers/pci/, e.g., pci_remap_iospace() is
>>>> also used in the DT path, where I suppose a defective DT could cause a
>>>> similar issue.
>>>> 
>>>>> port = pci_address_to_pio(cpu_addr);
>>>>> @@ -910,7 +918,7 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
>>>>> else {
>>>>> resource_list_for_each_entry_safe(entry, tmp, list) {
>>>>> if (entry->res->flags & IORESOURCE_IO)
>>>>> - acpi_pci_root_remap_iospace(&device->fwnode,
>>>>> + acpi_pci_root_remap_iospace(device,
>>>>> entry);
>>>>> 
>>>>> if (entry->res->flags & IORESOURCE_DISABLED)
>>>>> 
>>>>> ---
>>>>> base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba
>>>>> change-id: 20240813-check_pci_probe_res-27e3e6df72b2
>>>>> 
>>>>> Best regards,
>>>>> -- 
>>>>> Miao Wang <shankerwangmiao@gmail.com>