[RFC PATCH 1/3] pci, acpi: Match PCI config space accessors against platfrom specific ECAM quirks.
From: arnd@arndb.de (Arnd Bergmann)
Date: 2016-06-02 12:32:54
Also in:
linux-acpi, linux-pci, lkml
On Thursday, June 2, 2016 2:07:43 PM CEST Tomasz Nowicki wrote:
On 02.06.2016 13:42, Arnd Bergmann wrote:quoted
On Thursday, June 2, 2016 10:41:01 AM CEST Tomasz Nowicki wrote:quoted
+struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root) +{ + int bus_num = root->secondary.start; + int domain = root->segment; + struct pci_cfg_fixup *f; + + if (!mcfg_table) + return &pci_generic_ecam_ops; + + /* + * Match against platform specific quirks and return corresponding + * CAM ops. + * + * First match against PCI topology <domain:bus> then use OEM ID and + * OEM revision from MCFG table standard header. + */ + for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) { + if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) && + (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) && + (!strncmp(f->oem_id, mcfg_table->header.oem_id, + ACPI_OEM_ID_SIZE)) && + (f->oem_revision == mcfg_table->header.oem_revision)) + return f->ops; + } + /* No quirks, use ECAM */ + return &pci_generic_ecam_ops; +} + int pci_mcfg_lookup(struct acpi_pci_root *root)Can you explain the use of pci_ecam_ops instead of pci_ops here?I wanted to get associated bus_shift and use it to setup configuration region properly before calling pci_ecam_create. Please see next patch.
I see. It feels really odd to do it this way though, since having a nonstandard bus_shift essentially means not using anything resembling ECAM to start with. I realize that a lot of the host bridges are not ECAM, but because of this, it would be more logical to have their own pci_ops instead of pci_ecam_ops. Arnd