/* * Copyright (C) 2022 Michael Brown . * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. * * You can also choose to distribute this program under the terms of * the Unmodified Binary Distribution Licence (as given in the file * COPYING.UBDL), provided that you have satisfied its requirements. */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include #include #include #include /** @file * * Cloud VM PCI configuration space access * */ /** Cached PCI configuration space access API */ static struct { /** PCI bus:dev.fn address range */ struct pci_range range; /** API for this bus:dev.fn address */ struct pci_api *api; } pcicloud; /** * Find PCI configuration space access API for address * * @v busdevfn Starting PCI bus:dev.fn address * @v range PCI bus:dev.fn address range to fill in * @ret api Configuration space access API, or NULL */ static struct pci_api * pcicloud_find ( uint32_t busdevfn, struct pci_range *range ) { struct pci_range candidate; struct pci_api *api; uint32_t best = 0; uint32_t index; uint32_t first; uint32_t last; /* Return empty range on error */ range->count = 0; /* Try discovery via all known APIs */ for_each_table_entry ( api, PCI_APIS ) { /* Discover via this API */ api->pci_discover ( busdevfn, &candidate ); /* Check for a matching or new closest allocation */ index = ( busdevfn - candidate.start ); if ( ( index < candidate.count ) || ( index > best ) ) { memcpy ( range, &candidate, sizeof ( *range ) ); best = index; } /* Stop if this range contains the target bus:dev.fn address */ if ( index < candidate.count ) { first = range->start; last = ( range->start + range->count - 1 ); DBGC ( &pcicloud, "PCICLOUD [" PCI_FMT "," PCI_FMT ") " "using %s API\n", PCI_SEG ( first ), PCI_BUS ( first ), PCI_SLOT ( first ), PCI_FUNC ( first ), PCI_SEG ( last ), PCI_BUS ( last ), PCI_SLOT ( last ), PCI_FUNC ( last ), api->name ); return api; } } return NULL; } /** * Find next PCI bus:dev.fn address range in system * * @v busdevfn Starting PCI bus:dev.fn address * @v range PCI bus:dev.fn address range to fill in */ static void pcicloud_discover ( uint32_t busdevfn, struct pci_range *range ) { /* Find new range, if any */ pcicloud_find ( busdevfn, range ); } /** * Find configuration space access API for PCI device * * @v pci PCI device * @ret api Configuration space access API */ static struct pci_api * pcicloud_api ( struct pci_device *pci ) { struct pci_range *range = &pcicloud.range; struct pci_api *api; uint32_t first; uint32_t last; /* Reuse cached API if applicable */ if ( ( pci->busdevfn - range->start ) < range->count ) return pcicloud.api; /* Find highest priority API claiming this range */ api = pcicloud_find ( pci->busdevfn, range ); /* Fall back to lowest priority API for any unclaimed gaps in ranges */ if ( ! api ) { api = ( table_end ( PCI_APIS ) - 1 ); range->count = ( range->start - pci->busdevfn ); range->start = pci->busdevfn; first = range->start; last = ( range->start + range->count - 1 ); DBGC ( &pcicloud, "PCICLOUD [" PCI_FMT "," PCI_FMT ") falling " "back to %s API\n", PCI_SEG ( first ), PCI_BUS ( first ), PCI_SLOT ( first ), PCI_FUNC ( first ), PCI_SEG ( last ), PCI_BUS ( last ), PCI_SLOT ( last ), PCI_FUNC ( last ), api->name ); } /* Cache API for this range */ pcicloud.api = api; return api; } /** * Check if PCI bus probing is allowed * * @v pci PCI device * @ret ok Bus probing is allowed */ static int pcicloud_can_probe ( struct pci_device *pci ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_can_probe ( pci ); } /** * Read byte from PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value read * @ret rc Return status code */ static int pcicloud_read_config_byte ( struct pci_device *pci, unsigned int where, uint8_t *value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_read_config_byte ( pci, where, value ); } /** * Read 16-bit word from PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value read * @ret rc Return status code */ static int pcicloud_read_config_word ( struct pci_device *pci, unsigned int where, uint16_t *value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_read_config_word ( pci, where, value ); } /** * Read 32-bit dword from PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value read * @ret rc Return status code */ static int pcicloud_read_config_dword ( struct pci_device *pci, unsigned int where, uint32_t *value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_read_config_dword ( pci, where, value ); } /** * Write byte to PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value to be written * @ret rc Return status code */ static int pcicloud_write_config_byte ( struct pci_device *pci, unsigned int where, uint8_t value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_write_config_byte ( pci, where, value ); } /** * Write 16-bit word to PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value to be written * @ret rc Return status code */ static int pcicloud_write_config_word ( struct pci_device *pci, unsigned int where, uint16_t value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_write_config_word ( pci, where, value ); } /** * Write 32-bit dword to PCI configuration space * * @v pci PCI device * @v where Location within PCI configuration space * @v value Value to be written * @ret rc Return status code */ static int pcicloud_write_config_dword ( struct pci_device *pci, unsigned int where, uint32_t value ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_write_config_dword ( pci, where, value ); } /** * Map PCI bus address as an I/O address * * @v bus_addr PCI bus address * @v len Length of region * @ret io_addr I/O address, or NULL on error */ static void * pcicloud_ioremap ( struct pci_device *pci, unsigned long bus_addr, size_t len ) { struct pci_api *api = pcicloud_api ( pci ); return api->pci_ioremap ( pci, bus_addr, len ); } PROVIDE_PCIAPI ( cloud, pci_can_probe, pcicloud_can_probe ); PROVIDE_PCIAPI ( cloud, pci_discover, pcicloud_discover ); PROVIDE_PCIAPI ( cloud, pci_read_config_byte, pcicloud_read_config_byte ); PROVIDE_PCIAPI ( cloud, pci_read_config_word, pcicloud_read_config_word ); PROVIDE_PCIAPI ( cloud, pci_read_config_dword, pcicloud_read_config_dword ); PROVIDE_PCIAPI ( cloud, pci_write_config_byte, pcicloud_write_config_byte ); PROVIDE_PCIAPI ( cloud, pci_write_config_word, pcicloud_write_config_word ); PROVIDE_PCIAPI ( cloud, pci_write_config_dword, pcicloud_write_config_dword ); PROVIDE_PCIAPI ( cloud, pci_ioremap, pcicloud_ioremap );