From 906ee99dd2a5c819c1171ce5eaf6c080c027e58c Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 14 Feb 2013 14:02:12 -0700 Subject: vfio-pci: Cleanup BAR access We can actually handle MMIO and I/O port from the same access function since PCI already does abstraction of this. The ROM BAR only requires a minor difference, so it gets included too. vfio_pci_config_readwrite gets renamed for consistency. Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci.c | 26 ++-- drivers/vfio/pci/vfio_pci_config.c | 5 +- drivers/vfio/pci/vfio_pci_private.h | 15 +-- drivers/vfio/pci/vfio_pci_rdwr.c | 234 +++++++++++------------------------- 4 files changed, 90 insertions(+), 190 deletions(-) (limited to 'drivers/vfio/pci') diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 469e110d7ea6..bb8c8c2be960 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -371,31 +371,21 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf, { unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); struct vfio_pci_device *vdev = device_data; - struct pci_dev *pdev = vdev->pdev; if (index >= VFIO_PCI_NUM_REGIONS) return -EINVAL; switch (index) { case VFIO_PCI_CONFIG_REGION_INDEX: - return vfio_pci_config_readwrite(vdev, buf, count, - ppos, iswrite); + return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite); + case VFIO_PCI_ROM_REGION_INDEX: if (iswrite) return -EINVAL; - return vfio_pci_mem_readwrite(vdev, buf, count, ppos, false); + return vfio_pci_bar_rw(vdev, buf, count, ppos, false); case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: - { - unsigned long flags = pci_resource_flags(pdev, index); - - if (flags & IORESOURCE_IO) - return vfio_pci_io_readwrite(vdev, buf, count, - ppos, iswrite); - if (flags & IORESOURCE_MEM) - return vfio_pci_mem_readwrite(vdev, buf, count, - ppos, iswrite); - } + return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite); } return -EINVAL; @@ -404,13 +394,19 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf, static ssize_t vfio_pci_read(void *device_data, char __user *buf, size_t count, loff_t *ppos) { + if (!count) + return 0; + return vfio_pci_rw(device_data, buf, count, ppos, false); } static ssize_t vfio_pci_write(void *device_data, const char __user *buf, size_t count, loff_t *ppos) { - return vfio_pci_rw(device_data, buf, count, ppos, true); + if (!count) + return 0; + + return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true); } static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index c975d91e1ccc..f1dde2c0fe99 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1501,9 +1501,8 @@ static ssize_t vfio_config_do_rw(struct vfio_pci_device *vdev, char __user *buf, return ret; } -ssize_t vfio_pci_config_readwrite(struct vfio_pci_device *vdev, - char __user *buf, size_t count, - loff_t *ppos, bool iswrite) +ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev, char __user *buf, + size_t count, loff_t *ppos, bool iswrite) { size_t done = 0; int ret = 0; diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 611827cba8cd..00d19b953ce4 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -70,15 +70,12 @@ extern int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags, unsigned index, unsigned start, unsigned count, void *data); -extern ssize_t vfio_pci_config_readwrite(struct vfio_pci_device *vdev, - char __user *buf, size_t count, - loff_t *ppos, bool iswrite); -extern ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev, - char __user *buf, size_t count, - loff_t *ppos, bool iswrite); -extern ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, - char __user *buf, size_t count, - loff_t *ppos, bool iswrite); +extern ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev, + char __user *buf, size_t count, + loff_t *ppos, bool iswrite); + +extern ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf, + size_t count, loff_t *ppos, bool iswrite); extern int vfio_pci_init_perm_bits(void); extern void vfio_pci_uninit_perm_bits(void); diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index f72323ef618f..e9d78eb91ed7 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -20,250 +20,158 @@ #include "vfio_pci_private.h" -/* I/O Port BAR access */ -ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf, - size_t count, loff_t *ppos, bool iswrite) +/* + * 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) { - struct pci_dev *pdev = vdev->pdev; - loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; - int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos); - void __iomem *io; - size_t done = 0; - - if (!pci_resource_start(pdev, bar)) - return -EINVAL; - - if (pos + count > pci_resource_len(pdev, bar)) - return -EINVAL; - - if (!vdev->barmap[bar]) { - int ret; - - ret = pci_request_selected_regions(pdev, 1 << bar, "vfio"); - if (ret) - return ret; - - vdev->barmap[bar] = pci_iomap(pdev, bar, 0); - - if (!vdev->barmap[bar]) { - pci_release_selected_regions(pdev, 1 << bar); - return -EINVAL; - } - } - - io = vdev->barmap[bar]; + ssize_t done = 0; while (count) { - int filled; + 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 (count >= 3 && !(pos % 4)) { + if (fillable >= 4 && !(off % 4)) { __le32 val; if (iswrite) { if (copy_from_user(&val, buf, 4)) return -EFAULT; - iowrite32(le32_to_cpu(val), io + pos); + iowrite32(le32_to_cpu(val), io + off); } else { - val = cpu_to_le32(ioread32(io + pos)); + val = cpu_to_le32(ioread32(io + off)); if (copy_to_user(buf, &val, 4)) return -EFAULT; } filled = 4; - - } else if ((pos % 2) == 0 && count >= 2) { + } 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 + pos); + iowrite16(le16_to_cpu(val), io + off); } else { - val = cpu_to_le16(ioread16(io + pos)); + val = cpu_to_le16(ioread16(io + off)); if (copy_to_user(buf, &val, 2)) return -EFAULT; } filled = 2; - } else { + } else if (fillable) { u8 val; if (iswrite) { if (copy_from_user(&val, buf, 1)) return -EFAULT; - iowrite8(val, io + pos); + iowrite8(val, io + off); } else { - val = ioread8(io + pos); + 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; - pos += filled; } - *ppos += done; - return done; } -/* - * MMIO BAR access - * We handle two excluded ranges here as well, if the user tries to read - * the ROM beyond what PCI tells us is available or the MSI-X table region, - * we return 0xFF and writes are dropped. - */ -ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev, char __user *buf, - size_t count, loff_t *ppos, bool iswrite) +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); - void __iomem *io; + size_t x_start = 0, x_end = 0; resource_size_t end; - size_t done = 0; - size_t x_start = 0, x_end = 0; /* excluded range */ + void __iomem *io; + ssize_t done; if (!pci_resource_start(pdev, bar)) return -EINVAL; end = pci_resource_len(pdev, bar); - if (pos > end) + if (pos >= end) return -EINVAL; - if (pos == end) - return 0; - - if (pos + count > end) - count = end - pos; + 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; + } else if (!vdev->barmap[bar]) { + int ret; - vdev->barmap[bar] = pci_iomap(pdev, bar, 0); + ret = pci_request_selected_regions(pdev, 1 << bar, "vfio"); + if (ret) + return ret; - if (!vdev->barmap[bar]) { - pci_release_selected_regions(pdev, 1 << bar); - return -EINVAL; - } + 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; - } + if (bar == vdev->msix_bar) { + x_start = vdev->msix_offset; + x_end = vdev->msix_offset + vdev->msix_size; } - if (!io) - return -EINVAL; - - while (count) { - size_t fillable, filled; - - if (pos < x_start) - fillable = x_start - pos; - else if (pos >= x_end) - fillable = end - pos; - else - fillable = 0; - - if (fillable >= 4 && !(pos % 4) && (count >= 4)) { - __le32 val; - - if (iswrite) { - if (copy_from_user(&val, buf, 4)) - goto out; - - iowrite32(le32_to_cpu(val), io + pos); - } else { - val = cpu_to_le32(ioread32(io + pos)); - - if (copy_to_user(buf, &val, 4)) - goto out; - } - - filled = 4; - } else if (fillable >= 2 && !(pos % 2) && (count >= 2)) { - __le16 val; - - if (iswrite) { - if (copy_from_user(&val, buf, 2)) - goto out; - - iowrite16(le16_to_cpu(val), io + pos); - } else { - val = cpu_to_le16(ioread16(io + pos)); - - if (copy_to_user(buf, &val, 2)) - goto out; - } - - filled = 2; - } else if (fillable) { - u8 val; - - if (iswrite) { - if (copy_from_user(&val, buf, 1)) - goto out; - - iowrite8(val, io + pos); - } else { - val = ioread8(io + pos); - - if (copy_to_user(buf, &val, 1)) - goto out; - } - - filled = 1; - } else { - /* Drop writes, fill reads with FF */ - filled = min((size_t)(x_end - pos), count); - if (!iswrite) { - char val = 0xFF; - size_t i; + done = do_io_rw(io, buf, pos, count, x_start, x_end, iswrite); - for (i = 0; i < filled; i++) { - if (put_user(val, buf + i)) - goto out; - } - } + if (done >= 0) + *ppos += done; - } - - count -= filled; - done += filled; - buf += filled; - pos += filled; - } - - *ppos += done; - -out: if (bar == PCI_ROM_RESOURCE) pci_unmap_rom(pdev, io); - return count ? -EFAULT : done; + return done; } -- cgit v1.2.1