From cf0921bea66c55600a48009597caa5fcb1419748 Mon Sep 17 00:00:00 2001 From: KarimAllah Ahmed Date: Mon, 19 Mar 2018 21:06:00 +0100 Subject: PCI/IOV: Use VF0 cached config registers for other VFs Cache some config data from VF0 and use it for all other VFs instead of reading it from the config space of each VF. We assume these items are the same across all associated VFs: Revision ID Class Code Subsystem Vendor ID Subsystem ID This is an optimization when enabling SR-IOV on a device with many VFs. Signed-off-by: KarimAllah Ahmed [bhelgaas: changelog, simplify comments, remove unused "device", test CONFIG_PCI_IOV instead of CONFIG_PCI_ATS, rename functions] Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) (limited to 'drivers/pci/probe.c') diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 9f80b904bf76..708094f720fd 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1400,6 +1400,43 @@ int pci_cfg_space_size(struct pci_dev *dev) return PCI_CFG_SPACE_SIZE; } +static u32 pci_class(struct pci_dev *dev) +{ + u32 class; + +#ifdef CONFIG_PCI_IOV + if (dev->is_virtfn) + return dev->physfn->sriov->class; +#endif + pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); + return class; +} + +static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device) +{ +#ifdef CONFIG_PCI_IOV + if (dev->is_virtfn) { + *vendor = dev->physfn->sriov->subsystem_vendor; + *device = dev->physfn->sriov->subsystem_device; + return; + } +#endif + pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor); + pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device); +} + +static u8 pci_hdr_type(struct pci_dev *dev) +{ + u8 hdr_type; + +#ifdef CONFIG_PCI_IOV + if (dev->is_virtfn) + return dev->physfn->sriov->hdr_type; +#endif + pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type); + return hdr_type; +} + #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED) static void pci_msi_setup_pci_dev(struct pci_dev *dev) @@ -1465,8 +1502,7 @@ int pci_setup_device(struct pci_dev *dev) struct pci_bus_region region; struct resource *res; - if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type)) - return -EIO; + hdr_type = pci_hdr_type(dev); dev->sysdata = dev->bus->sysdata; dev->dev.parent = dev->bus->bridge; @@ -1488,7 +1524,8 @@ int pci_setup_device(struct pci_dev *dev) dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)); - pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); + class = pci_class(dev); + dev->revision = class & 0xff; dev->class = class >> 8; /* upper 3 bytes */ @@ -1528,8 +1565,8 @@ int pci_setup_device(struct pci_dev *dev) goto bad; pci_read_irq(dev); pci_read_bases(dev, 6, PCI_ROM_ADDRESS); - pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor); - pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device); + + pci_subsystem_ids(dev, &dev->subsystem_vendor, &dev->subsystem_device); /* * Do the ugly legacy mode stuff here rather than broken chip -- cgit