Fixed MTP to work with TWRP

drivers/vfio/pci/vfio_pci_rdwr.c

@@ -0,0 +1,238 @@
+/*
+ * 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;
+}