src/drivers/bus/pcicloud.c - ipxe - Git at Google

 /*
  * Copyright (C) 2022 Michael Brown <mbrown@fensystems.co.uk>.
  *
  * 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 <stdint.h>
 #include <string.h>
 #include <ipxe/pci.h>
 #include <ipxe/pcicloud.h>

 /** @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 );
	/*
	* Copyright (C) 2022 Michael Brown <mbrown@fensystems.co.uk>.
	*
	* 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 <stdint.h>
	#include <string.h>
	#include <ipxe/pci.h>
	#include <ipxe/pcicloud.h>

	/** @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 );