[pci] Add a mechanism for using a PCI VPD field as an NVS device

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/nvs/nvsvpd.c

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2010 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdio.h>
+#include <ipxe/nvs.h>
+#include <ipxe/pci.h>
+#include <ipxe/pcivpd.h>
+#include <ipxe/nvsvpd.h>
+
+/** @file
+ *
+ * Non-Volatile Storage using Vital Product Data
+ *
+ */
+
+/**
+ * Read from VPD
+ *
+ * @v nvs		NVS device
+ * @v address		Starting address
+ * @v buf		Data buffer
+ * @v len		Length of data buffer
+ * @ret rc		Return status code
+ */
+static int nvs_vpd_read ( struct nvs_device *nvs, unsigned int address,
+			  void *data, size_t len ) {
+	struct nvs_vpd_device *nvsvpd =
+		container_of ( nvs, struct nvs_vpd_device, nvs );
+	int rc;
+
+	if ( ( rc = pci_vpd_read ( &nvsvpd->vpd, ( nvsvpd->address + address ),
+				   data, len ) ) != 0 ) {
+		DBGC ( nvsvpd->vpd.pci, PCI_FMT " NVS could not read "
+		       "[%04x,%04zx): %s\n", PCI_ARGS ( nvsvpd->vpd.pci ),
+		       address, ( address + len ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Write to VPD
+ *
+ * @v nvs		NVS device
+ * @v address		Starting address
+ * @v buf		Data buffer
+ * @v len		Length of data buffer
+ * @ret rc		Return status code
+ */
+static int nvs_vpd_write ( struct nvs_device *nvs, unsigned int address,
+			   const void *data, size_t len ) {
+	struct nvs_vpd_device *nvsvpd =
+		container_of ( nvs, struct nvs_vpd_device, nvs );
+	int rc;
+
+	if ( ( rc = pci_vpd_write ( &nvsvpd->vpd, ( nvsvpd->address + address ),
+				    data, len ) ) != 0 ) {
+		DBGC ( nvsvpd->vpd.pci, PCI_FMT " NVS could not write "
+		       "[%04x,%04zx): %s\n", PCI_ARGS ( nvsvpd->vpd.pci ),
+		       address, ( address + len ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Initialise NVS VPD device
+ *
+ * @v nvsvpd		NVS VPD device
+ * @v pci		PCI device
+ * @ret rc		Return status code
+ */
+int nvs_vpd_init ( struct nvs_vpd_device *nvsvpd, struct pci_device *pci,
+		   unsigned int field ) {
+	size_t len;
+	int rc;
+
+	/* Initialise VPD device */
+	if ( ( rc = pci_vpd_init ( &nvsvpd->vpd, pci ) ) != 0 ) {
+		DBGC ( pci, PCI_FMT " NVS could not initialise "
+		       "VPD: %s\n", PCI_ARGS ( pci ), strerror ( rc ) );
+		return rc;
+	}
+
+	/* Locate VPD field */
+	if ( ( rc = pci_vpd_find ( &nvsvpd->vpd, field, &nvsvpd->address,
+				   &len ) ) != 0 ) {
+		DBGC ( pci, PCI_FMT " NVS could not locate VPD field "
+		       PCI_VPD_FIELD_FMT ": %s\n", PCI_ARGS ( pci ),
+		       PCI_VPD_FIELD_ARGS ( field ), strerror ( rc ) );
+		return rc;
+	}
+
+	/* Initialise NVS device */
+	nvsvpd->nvs.block_size = 1;
+	nvsvpd->nvs.size = len;
+	nvsvpd->nvs.read = nvs_vpd_read;
+	nvsvpd->nvs.write = nvs_vpd_write;
+
+	DBGC ( pci, PCI_FMT " NVS using VPD field " PCI_VPD_FIELD_FMT " at "
+	       "[%04x,%04x)\n", PCI_ARGS ( pci ), PCI_VPD_FIELD_ARGS ( field ),
+	       nvsvpd->address, ( nvsvpd->address + nvsvpd->nvs.size ) );
+
+	return 0;
+}

src/include/ipxe/nvsvpd.h

@@ -0,0 +1,33 @@
+#ifndef _IPXE_NVSVPD_H
+#define _IPXE_NVSVPD_H
+
+/**
+ * @file
+ *
+ * Non-Volatile Storage using Vital Product Data
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <ipxe/nvs.h>
+#include <ipxe/pcivpd.h>
+
+/** An NVS VPD device */
+struct nvs_vpd_device {
+	/** NVS device */
+	struct nvs_device nvs;
+	/** PCI VPD device */
+	struct pci_vpd vpd;
+	/** Starting address
+	 *
+	 * This address is added to the NVS address to form the VPD
+	 * address.
+	 */
+	unsigned int address;
+};
+
+extern int nvs_vpd_init ( struct nvs_vpd_device *nvsvpd, struct pci_device *pci,
+			  unsigned int field );
+
+#endif /* IPXE_NVSVPD_H */