--- /dev/null
+/*
+ * VFIO PCI I/O Port & MMIO access
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
+ * Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc. All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#include <linux/fs.h>
+#include <linux/pci.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/vgaarb.h>
+
+#include "vfio_pci_private.h"
+
+/*
+ * Read or write from an __iomem region (MMIO or I/O port) with an excluded
+ * range which is inaccessible. The excluded range drops writes and fills
+ * reads with -1. This is intended for handling MSI-X vector tables and
+ * leftover space for ROM BARs.
+ */
+static ssize_t do_io_rw(void __iomem *io, char __user *buf,
+ loff_t off, size_t count, size_t x_start,
+ size_t x_end, bool iswrite)
+{
+ ssize_t done = 0;
+
+ while (count) {
+ size_t fillable, filled;
+
+ if (off < x_start)
+ fillable = min(count, (size_t)(x_start - off));
+ else if (off >= x_end)
+ fillable = count;
+ else
+ fillable = 0;
+
+ if (fillable >= 4 && !(off % 4)) {
+ __le32 val;
+
+ if (iswrite) {
+ if (copy_from_user(&val, buf, 4))
+ return -EFAULT;
+
+ iowrite32(le32_to_cpu(val), io + off);
+ } else {
+ val = cpu_to_le32(ioread32(io + off));
+
+ if (copy_to_user(buf, &val, 4))
+ return -EFAULT;
+ }
+
+ filled = 4;
+ } else if (fillable >= 2 && !(off % 2)) {
+ __le16 val;
+
+ if (iswrite) {
+ if (copy_from_user(&val, buf, 2))
+ return -EFAULT;
+
+ iowrite16(le16_to_cpu(val), io + off);
+ } else {
+ val = cpu_to_le16(ioread16(io + off));
+
+ if (copy_to_user(buf, &val, 2))
+ return -EFAULT;
+ }
+
+ filled = 2;
+ } else if (fillable) {
+ u8 val;
+
+ if (iswrite) {
+ if (copy_from_user(&val, buf, 1))
+ return -EFAULT;
+
+ iowrite8(val, io + off);
+ } else {
+ val = ioread8(io + off);
+
+ if (copy_to_user(buf, &val, 1))
+ return -EFAULT;
+ }
+
+ filled = 1;
+ } else {
+ /* Fill reads with -1, drop writes */
+ filled = min(count, (size_t)(x_end - off));
+ if (!iswrite) {
+ u8 val = 0xFF;
+ size_t i;
+
+ for (i = 0; i < filled; i++)
+ if (copy_to_user(buf + i, &val, 1))
+ return -EFAULT;
+ }
+ }
+
+ count -= filled;
+ done += filled;
+ off += filled;
+ buf += filled;
+ }
+
+ return done;
+}
+
+ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ size_t x_start = 0, x_end = 0;
+ resource_size_t end;
+ void __iomem *io;
+ ssize_t done;
+
+ if (!pci_resource_start(pdev, bar))
+ return -EINVAL;
+
+ end = pci_resource_len(pdev, bar);
+
+ if (pos >= end)
+ return -EINVAL;
+
+ count = min(count, (size_t)(end - pos));
+
+ if (bar == PCI_ROM_RESOURCE) {
+ /*
+ * The ROM can fill less space than the BAR, so we start the
+ * excluded range at the end of the actual ROM. This makes
+ * filling large ROM BARs much faster.
+ */
+ io = pci_map_rom(pdev, &x_start);
+ if (!io)
+ return -ENOMEM;
+ x_end = end;
+ } else if (!vdev->barmap[bar]) {
+ int ret;
+
+ ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+ if (ret)
+ return ret;
+
+ io = pci_iomap(pdev, bar, 0);
+ if (!io) {
+ pci_release_selected_regions(pdev, 1 << bar);
+ return -ENOMEM;
+ }
+
+ vdev->barmap[bar] = io;
+ } else
+ io = vdev->barmap[bar];
+
+ if (bar == vdev->msix_bar) {
+ x_start = vdev->msix_offset;
+ x_end = vdev->msix_offset + vdev->msix_size;
+ }
+
+ done = do_io_rw(io, buf, pos, count, x_start, x_end, iswrite);
+
+ if (done >= 0)
+ *ppos += done;
+
+ if (bar == PCI_ROM_RESOURCE)
+ pci_unmap_rom(pdev, io);
+
+ return done;
+}
+
+ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ int ret;
+ loff_t off, pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ void __iomem *iomem = NULL;
+ unsigned int rsrc;
+ bool is_ioport;
+ ssize_t done;
+
+ if (!vdev->has_vga)
+ return -EINVAL;
+
+ switch (pos) {
+ case 0xa0000 ... 0xbffff:
+ count = min(count, (size_t)(0xc0000 - pos));
+ iomem = ioremap_nocache(0xa0000, 0xbffff - 0xa0000 + 1);
+ off = pos - 0xa0000;
+ rsrc = VGA_RSRC_LEGACY_MEM;
+ is_ioport = false;
+ break;
+ case 0x3b0 ... 0x3bb:
+ count = min(count, (size_t)(0x3bc - pos));
+ iomem = ioport_map(0x3b0, 0x3bb - 0x3b0 + 1);
+ off = pos - 0x3b0;
+ rsrc = VGA_RSRC_LEGACY_IO;
+ is_ioport = true;
+ break;
+ case 0x3c0 ... 0x3df:
+ count = min(count, (size_t)(0x3e0 - pos));
+ iomem = ioport_map(0x3c0, 0x3df - 0x3c0 + 1);
+ off = pos - 0x3c0;
+ rsrc = VGA_RSRC_LEGACY_IO;
+ is_ioport = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!iomem)
+ return -ENOMEM;
+
+ ret = vga_get_interruptible(vdev->pdev, rsrc);
+ if (ret) {
+ is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+ return ret;
+ }
+
+ done = do_io_rw(iomem, buf, off, count, 0, 0, iswrite);
+
+ vga_put(vdev->pdev, rsrc);
+
+ is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+
+ if (done >= 0)
+ *ppos += done;
+
+ return done;
+}
Code Review / kvmfornfv.git / blobdiff