Revert "PCI/IOV: Use VF0 cached config space size for other VFs" (76bf6a86) · Commits · 戴 / test

Revert ("PCI/IOV: Use VF0 cached config space size for other VFs"), which attempted to cache the config space size from the first VF to re-use for subsequent VFs. The cached value was determined prior to discovering the PCIe capability on the VF, which resulted in the first VF reporting the correct config space size (4K), as it has a special case through pci_cfg_space_size(), while all the other VFs only reported 256 bytes. As this was only a performance optimization, we're better off without it. Fixes: ("PCI/IOV: Use VF0 cached config space size for other VFs") Link: https://lore.kernel.org/r/156046663197.29869.3633634445109057665.stgit@gimli.home Signed-off-by:

Alex Williamson <alex.williamson@redhat.com> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com> Cc: KarimAllah Ahmed <karahmed@amazon.de> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Cc: Hao Zheng <yinhe@linux.alibaba.com>

drivers/pci/iov.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -132,8 +132,6 @@ static void pci_read_vf_config_common(struct pci_dev *virtfn)
		&physfn->sriov->subsystem_vendor);
		pci_read_config_word(virtfn, PCI_SUBSYSTEM_ID,
		&physfn->sriov->subsystem_device);

		physfn->sriov->cfg_size = pci_cfg_space_size(virtfn);
		}

		int pci_iov_add_virtfn(struct pci_dev *dev, int id)

drivers/pci/pci.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -293,7 +293,6 @@ struct pci_sriov {
		u16 driver_max_VFs; /* Max num VFs driver supports */
		struct pci_dev dev; / Lowest numbered PF */
		struct pci_dev self; / This PF */
		u32 cfg_size; /* VF config space size */
		u32 class; /* VF device */
		u8 hdr_type; /* VF header type */
		u16 subsystem_vendor; /* VF subsystem vendor */

drivers/pci/probe.c

+0 −17

Original line number	Diff line number	Diff line
		@@ -1555,29 +1555,12 @@ static int pci_cfg_space_size_ext(struct pci_dev *dev)
		return PCI_CFG_SPACE_EXP_SIZE;
		}

		#ifdef CONFIG_PCI_IOV
		static bool is_vf0(struct pci_dev *dev)
		{
		if (pci_iov_virtfn_devfn(dev->physfn, 0) == dev->devfn &&
		pci_iov_virtfn_bus(dev->physfn, 0) == dev->bus->number)
		return true;

		return false;
		}
		#endif

		int pci_cfg_space_size(struct pci_dev *dev)
		{
		int pos;
		u32 status;
		u16 class;

		#ifdef CONFIG_PCI_IOV
		/* Read cached value for all VFs except for VF0 */
		if (dev->is_virtfn && !is_vf0(dev))
		return dev->physfn->sriov->cfg_size;
		#endif

		if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG)
		return PCI_CFG_SPACE_SIZE;

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