--- /dev/null
+/*
+ * Copyright (C) 2013 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdio.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <linux_api.h>
+#include <ipxe/linux.h>
+#include <ipxe/pci.h>
+
+/** @file
+ *
+ * iPXE PCI API for Linux
+ *
+ */
+
+/**
+ * Open PCI configuration space
+ *
+ * @v pci PCI device
+ * @v flags Access mode flags
+ * @v where Address within configuration space
+ * @ret fd File handle, or negative error
+ */
+static int linux_pci_open ( struct pci_device *pci, int flags,
+ unsigned long where ) {
+ char filename[ 22 /* "/proc/bus/pci/xx/xx.x" + NUL */ ];
+ int fd;
+ int rc;
+
+ /* Construct filename */
+ snprintf ( filename, sizeof ( filename ), "/proc/bus/pci/%02x/%02x.%x",
+ PCI_BUS ( pci->busdevfn ), PCI_SLOT ( pci->busdevfn ),
+ PCI_FUNC ( pci->busdevfn ) );
+
+ /* Open file */
+ fd = linux_open ( filename, flags );
+ if ( fd < 0 ) {
+ DBGC ( pci, "PCI could not open %s: %s\n", filename,
+ linux_strerror ( linux_errno ) );
+ rc = -ELINUX ( linux_errno );
+ goto err_open;
+ }
+
+ /* Seek to location */
+ if ( linux_lseek ( fd, where, SEEK_SET ) < 0 ) {
+ DBGC ( pci, "PCI could not seek to %s offset %#02lx: %s\n",
+ filename, where, linux_strerror ( linux_errno ) );
+ rc = -ELINUX ( linux_errno );
+ goto err_seek;
+ }
+
+ return fd;
+
+ err_seek:
+ linux_close ( fd );
+ err_open:
+ return rc;
+}
+
+/**
+ * Read from PCI configuration space
+ *
+ * @v pci PCI device
+ * @v where Address within configuration space
+ * @v value Data buffer
+ * @v len Length to read
+ * @ret rc Return status code
+ */
+int linux_pci_read ( struct pci_device *pci, unsigned long where,
+ unsigned long *value, size_t len ) {
+ uint32_t tmp = 0;
+ int fd;
+ int check_len;
+ int rc;
+
+ /* Return "missing device" in case of error */
+ *value = -1UL;
+
+ /* Open configuration space */
+ fd = linux_pci_open ( pci, O_RDONLY, where );
+ if ( fd < 0 ) {
+ rc = fd;
+ goto err_open;
+ }
+
+ /* Read value */
+ check_len = linux_read ( fd, &tmp, len );
+ if ( check_len < 0 ) {
+ DBGC ( pci, "PCI could not read from " PCI_FMT " %#02lx+%#zx: "
+ "%s\n", PCI_ARGS ( pci ), where, len,
+ linux_strerror ( linux_errno ) );
+ rc = -ELINUX ( linux_errno );
+ goto err_read;
+ }
+ if ( ( size_t ) check_len != len ) {
+ DBGC ( pci, "PCI read only %#x bytes from " PCI_FMT
+ " %#02lx+%#zx\n", check_len, PCI_ARGS ( pci ),
+ where, len );
+ rc = -EIO;
+ goto err_read;
+ }
+
+ /* Return value */
+ *value = le32_to_cpu ( tmp );
+
+ /* Success */
+ rc = 0;
+
+ err_read:
+ linux_close ( fd );
+ err_open:
+ return rc;
+}
+
+/**
+ * Write to PCI configuration space
+ *
+ * @v pci PCI device
+ * @v where Address within configuration space
+ * @v value Value to write
+ * @v len Length of value
+ * @ret rc Return status code
+ */
+int linux_pci_write ( struct pci_device *pci, unsigned long where,
+ unsigned long value, size_t len ) {
+ uint32_t tmp;
+ int fd;
+ int check_len;
+ int rc;
+
+ /* Open configuration space */
+ fd = linux_pci_open ( pci, O_WRONLY, where );
+ if ( fd < 0 ) {
+ rc = fd;
+ goto err_open;
+ }
+
+ /* Prepare value for writing */
+ tmp = cpu_to_le32 ( value );
+ assert ( len <= sizeof ( tmp ) );
+
+ /* Write value */
+ check_len = linux_write ( fd, &tmp, len );
+ if ( check_len < 0 ) {
+ DBGC ( pci, "PCI could not write to " PCI_FMT " %#02lx+%#zx: "
+ "%s\n", PCI_ARGS ( pci ), where, len,
+ linux_strerror ( linux_errno ) );
+ rc = -ELINUX ( linux_errno );
+ goto err_write;
+ }
+ if ( ( size_t ) check_len != len ) {
+ DBGC ( pci, "PCI wrote only %#x bytes to " PCI_FMT
+ " %#02lx+%#zx\n", check_len, PCI_ARGS ( pci ),
+ where, len );
+ rc = -EIO;
+ goto err_write;
+ }
+
+ /* Success */
+ rc = 0;
+
+ err_write:
+ linux_close ( fd );
+ err_open:
+ return rc;
+}
Code Review / kvmfornfv.git / blobdiff