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From: Yicong Yang <yangyicong@hisilicon.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: <helgaas@kernel.org>, <linux-pci@vger.kernel.org>,
	<kvalo@codeaurora.org>, <linuxarm@huawei.com>
Subject: Re: [RFC PATCH] PCI: Use pci_pcie_find_root_port() to get root port
Date: Sat, 18 Apr 2020 09:08:53 +0800	[thread overview]
Message-ID: <693330fe-ee71-567a-dc0f-63e20ba8eb0c@hisilicon.com> (raw)
In-Reply-To: <20200417092310.GR2586@lahna.fi.intel.com>



On 2020/4/17 17:23, Mika Westerberg wrote:
> On Tue, Apr 07, 2020 at 08:31:57PM +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 no need to
>> distinguish the type of the device.
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
>> ---
>>  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                             | 14 +++++++-------
>>  8 files changed, 15 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);
>>  }
> For thunderbolt change,
>
> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
>
> Below is a minor comment that you may want to consider.
>
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 3840a54..b341ca30 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 +2123,16 @@ 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
>> + */
> I think it may be good to add a bit more description here for example you
> can take the pci_find_pcie_root_port() kernel-doc and use it here.

Sure. Thanks.

Regards,
Yicong


>
>> +static inline struct pci_dev *pci_pcie_find_root_port(struct pci_dev *dev)
>>  {
>> -	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;
>>  	}
>>  	return NULL;
>> --
>> 2.8.1
> .
>


      reply	other threads:[~2020-04-18  1:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-07 12:31 [RFC PATCH] PCI: Use pci_pcie_find_root_port() to get root port Yicong Yang
2020-04-07 15:00 ` Kalle Valo
2020-04-17  9:23 ` Mika Westerberg
2020-04-18  1:08   ` Yicong Yang [this message]

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