On 2020/5/7 3:48, Bjorn Helgaas wrote:
> On Wed, May 06, 2020 at 08:42:56PM +0800, Yicong Yang wrote:
>> Previously we use pcie_find_root_port() to get root port from a pcie
>> device, use pci_find_pcie_root_port() to get root port from a pci
>> device, which increase the complexity.
>>
>> Unify the two functions and use pci_pcie_find_root_port() to get root
>> port from both pci device and pcie device. Then there is not need to
>> distinguish the type of the device.
>>
>> Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
>> Acked-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> // for wireless
>> Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> // for thunderbolt
> When I first looked at this, I got distracted because I think many of
> the calls of these functions should go away. That's out of scope
> right now, but I'll just mention them for the archives:
>
> - iwl_trans_pcie_dump_regs() dumps AER registers, which should be
> done by the PCI core, not by the driver.
>
> - pcie_root_rcb_set() looks up the Root Port's RCB setting, which
> could easily be inherited.
>
> - aer_inject(). I'm not convinced anybody uses this, and we have
> the ACPI EINJ path, which should test a lot more of the path.
>
> - acpi_pci_bridge_d3() looks up the "HotPlugSupportInD3", which
> probably could also be inherited.
>
> - pci_configure_relaxed_ordering() looks up the Root Port's Relaxed
> Ordering support, which could be inherited.
>
>> ---
>> Change since v1:
>> - Add Mika's Ack for thunderbolt part
>> - Add description for pci_pcie_find_root_port()
>>
>> drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 2 +-
>> drivers/pci/pci-acpi.c | 4 ++--
>> drivers/pci/pci.c | 24 ------------------------
>> drivers/pci/pcie/aer_inject.c | 2 +-
>> drivers/pci/probe.c | 2 +-
>> drivers/pci/quirks.c | 2 +-
>> drivers/thunderbolt/switch.c | 4 ++--
>> include/linux/pci.h | 17 ++++++++++-------
>> 8 files changed, 18 insertions(+), 39 deletions(-)
>>
>> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
>> index 38d8fe2..556cb8c 100644
>> --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
>> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
>> @@ -158,7 +158,7 @@ void iwl_trans_pcie_dump_regs(struct iwl_trans *trans)
>>
>> /* Print root port AER registers */
>> pos = 0;
>> - pdev = pcie_find_root_port(pdev);
>> + pdev = pci_pcie_find_root_port(pdev);
>> if (pdev)
>> pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
>> if (pos) {
>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
>> index 0c02d50..9316533 100644
>> --- a/drivers/pci/pci-acpi.c
>> +++ b/drivers/pci/pci-acpi.c
>> @@ -246,7 +246,7 @@ static acpi_status decode_type1_hpx_record(union acpi_object *record,
>>
>> static bool pcie_root_rcb_set(struct pci_dev *dev)
>> {
>> - struct pci_dev *rp = pcie_find_root_port(dev);
>> + struct pci_dev *rp = pci_pcie_find_root_port(dev);
>> u16 lnkctl;
>>
>> if (!rp)
>> @@ -948,7 +948,7 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
>> * Look for a special _DSD property for the root port and if it
>> * is set we know the hierarchy behind it supports D3 just fine.
>> */
>> - root = pci_find_pcie_root_port(dev);
>> + root = pci_pcie_find_root_port(dev);
>> if (!root)
>> return false;
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index d828ca8..fc5e7b6 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -695,30 +695,6 @@ struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
>> EXPORT_SYMBOL(pci_find_resource);
>>
>> /**
>> - * pci_find_pcie_root_port - return PCIe Root Port
>> - * @dev: PCI device to query
>> - *
>> - * Traverse up the parent chain and return the PCIe Root Port PCI Device
>> - * for a given PCI Device.
>> - */
>> -struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
>> -{
>> - struct pci_dev *bridge, *highest_pcie_bridge = dev;
>> -
>> - bridge = pci_upstream_bridge(dev);
>> - while (bridge && pci_is_pcie(bridge)) {
>> - highest_pcie_bridge = bridge;
>> - bridge = pci_upstream_bridge(bridge);
>> - }
>> -
>> - if (pci_pcie_type(highest_pcie_bridge) != PCI_EXP_TYPE_ROOT_PORT)
>> - return NULL;
>> -
>> - return highest_pcie_bridge;
>> -}
>> -EXPORT_SYMBOL(pci_find_pcie_root_port);
>> -
>> -/**
>> * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos
>> * @dev: the PCI device to operate on
>> * @pos: config space offset of status word
>> diff --git a/drivers/pci/pcie/aer_inject.c b/drivers/pci/pcie/aer_inject.c
>> index 6988fe7..c3bfc1b5 100644
>> --- a/drivers/pci/pcie/aer_inject.c
>> +++ b/drivers/pci/pcie/aer_inject.c
>> @@ -332,7 +332,7 @@ static int aer_inject(struct aer_error_inj *einj)
>> dev = pci_get_domain_bus_and_slot(einj->domain, einj->bus, devfn);
>> if (!dev)
>> return -ENODEV;
>> - rpdev = pcie_find_root_port(dev);
>> + rpdev = pci_pcie_find_root_port(dev);
>> if (!rpdev) {
>> pci_err(dev, "Root port not found\n");
>> ret = -ENODEV;
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 512cb43..50f7733 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -2015,7 +2015,7 @@ static void pci_configure_relaxed_ordering(struct pci_dev *dev)
>> * For now, we only deal with Relaxed Ordering issues with Root
>> * Ports. Peer-to-Peer DMA is another can of worms.
>> */
>> - root = pci_find_pcie_root_port(dev);
>> + root = pci_pcie_find_root_port(dev);
>> if (!root)
>> return;
>>
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index 29f473e..ac62675 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -4253,7 +4253,7 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_AMD, 0x1a02, PCI_CLASS_NOT_DEFINED,
>> */
>> static void quirk_disable_root_port_attributes(struct pci_dev *pdev)
>> {
>> - struct pci_dev *root_port = pci_find_pcie_root_port(pdev);
>> + struct pci_dev *root_port = pci_pcie_find_root_port(pdev);
>>
>> if (!root_port) {
>> pci_warn(pdev, "PCIe Completion erratum may cause device errors\n");
>> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
>> index a2ce990..90844c1 100644
>> --- a/drivers/thunderbolt/switch.c
>> +++ b/drivers/thunderbolt/switch.c
>> @@ -263,7 +263,7 @@ static void nvm_authenticate_start_dma_port(struct tb_switch *sw)
>> * itself. To be on the safe side keep the root port in D0 during
>> * the whole upgrade process.
>> */
>> - root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev);
>> + root_port = pci_pcie_find_root_port(sw->tb->nhi->pdev);
>> if (root_port)
>> pm_runtime_get_noresume(&root_port->dev);
>> }
>> @@ -272,7 +272,7 @@ static void nvm_authenticate_complete_dma_port(struct tb_switch *sw)
>> {
>> struct pci_dev *root_port;
>>
>> - root_port = pci_find_pcie_root_port(sw->tb->nhi->pdev);
>> + root_port = pci_pcie_find_root_port(sw->tb->nhi->pdev);
>> if (root_port)
>> pm_runtime_put(&root_port->dev);
>> }
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 3840a54..51881a1 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -1011,7 +1011,6 @@ void pci_bus_add_device(struct pci_dev *dev);
>> void pci_read_bridge_bases(struct pci_bus *child);
>> struct resource *pci_find_parent_resource(const struct pci_dev *dev,
>> struct resource *res);
>> -struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev);
>> u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin);
>> int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge);
>> u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp);
>> @@ -2124,15 +2123,19 @@ static inline int pci_pcie_type(const struct pci_dev *dev)
>> return (pcie_caps_reg(dev) & PCI_EXP_FLAGS_TYPE) >> 4;
>> }
>>
>> -static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
>> +/**
>> + * pci_pcie_find_root_port - Get the PCIe root port device
>> + * @dev: PCI device
>> + *
>> + * Traverse up the parent chain and return the PCIe Root Port PCI Device
>> + * for a given PCI/PCIe Device.
>> + */
>> +static inline struct pci_dev *pci_pcie_find_root_port(struct pci_dev *dev)
> The point of this is to find a Root Port regardless of whether "dev"
> is PCI or PCIe. So I think pcie_find_root_port() is sufficient; we
> don't need both "pci" and "pcie" in the name.
Okay.
>
>> {
>> - while (1) {
>> - if (!pci_is_pcie(dev))
>> - break;
>> + dev = pci_physfn(dev);
>> + while (dev) {
>> if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
>> return dev;
>> - if (!dev->bus->self)
>> - break;
>> dev = dev->bus->self;
> Why not use pci_upstream_bridge() here?
We'll judge whether the device is virtual or not every time we call
pci_upstream_bridge(). I think it's unnecessary and we only need to get
the physical function at the beginning of the traverse. It's okay to
use pci_upstream_bridge() here if you suggest so.
Regards,
Yicong
>
>> }
>> return NULL;
>> --
>> 2.8.1
>>
> .
>
