1 files changed, 269 insertions, 0 deletions
diff --git a/src/drivers/bus/pcicloud.c b/src/drivers/bus/pcicloud.c
new file mode 100644
index 000000000..0173c3158
--- /dev/null
+++ b/src/drivers/bus/pcicloud.c
@@ -0,0 +1,269 @@
+/*
+ * 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 );