![Ben Hutchings](/assets/img/avatar_default.png)
The variable for the 'permissive' module parameter used to be static
but was recently changed to be extern. This puts it in the kernel
global namespace if the driver is built-in, so its name should begin
with a prefix identifying the driver.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: af6fc858a3
("xen-pciback: limit guest control of command register")
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
434 lines
9.8 KiB
C
434 lines
9.8 KiB
C
/*
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* PCI Backend - Handles the virtual fields in the configuration space headers.
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*
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* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include "pciback.h"
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#include "conf_space.h"
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struct pci_cmd_info {
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u16 val;
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};
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struct pci_bar_info {
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u32 val;
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u32 len_val;
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int which;
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};
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#define is_enable_cmd(value) ((value)&(PCI_COMMAND_MEMORY|PCI_COMMAND_IO))
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#define is_master_cmd(value) ((value)&PCI_COMMAND_MASTER)
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/* Bits guests are allowed to control in permissive mode. */
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#define PCI_COMMAND_GUEST (PCI_COMMAND_MASTER|PCI_COMMAND_SPECIAL| \
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PCI_COMMAND_INVALIDATE|PCI_COMMAND_VGA_PALETTE| \
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PCI_COMMAND_WAIT|PCI_COMMAND_FAST_BACK)
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static void *command_init(struct pci_dev *dev, int offset)
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{
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struct pci_cmd_info *cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
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int err;
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if (!cmd)
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return ERR_PTR(-ENOMEM);
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err = pci_read_config_word(dev, PCI_COMMAND, &cmd->val);
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if (err) {
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kfree(cmd);
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return ERR_PTR(err);
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}
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return cmd;
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}
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static int command_read(struct pci_dev *dev, int offset, u16 *value, void *data)
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{
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int ret = pci_read_config_word(dev, offset, value);
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const struct pci_cmd_info *cmd = data;
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*value &= PCI_COMMAND_GUEST;
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*value |= cmd->val & ~PCI_COMMAND_GUEST;
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return ret;
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}
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static int command_write(struct pci_dev *dev, int offset, u16 value, void *data)
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{
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struct xen_pcibk_dev_data *dev_data;
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int err;
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u16 val;
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struct pci_cmd_info *cmd = data;
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dev_data = pci_get_drvdata(dev);
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if (!pci_is_enabled(dev) && is_enable_cmd(value)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: enable\n",
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pci_name(dev));
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err = pci_enable_device(dev);
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if (err)
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return err;
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if (dev_data)
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dev_data->enable_intx = 1;
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} else if (pci_is_enabled(dev) && !is_enable_cmd(value)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: disable\n",
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pci_name(dev));
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pci_disable_device(dev);
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if (dev_data)
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dev_data->enable_intx = 0;
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}
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if (!dev->is_busmaster && is_master_cmd(value)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: set bus master\n",
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pci_name(dev));
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pci_set_master(dev);
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} else if (dev->is_busmaster && !is_master_cmd(value)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: clear bus master\n",
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pci_name(dev));
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pci_clear_master(dev);
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}
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if (!(cmd->val & PCI_COMMAND_INVALIDATE) &&
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(value & PCI_COMMAND_INVALIDATE)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG
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DRV_NAME ": %s: enable memory-write-invalidate\n",
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pci_name(dev));
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err = pci_set_mwi(dev);
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if (err) {
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pr_warn("%s: cannot enable memory-write-invalidate (%d)\n",
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pci_name(dev), err);
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value &= ~PCI_COMMAND_INVALIDATE;
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}
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} else if ((cmd->val & PCI_COMMAND_INVALIDATE) &&
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!(value & PCI_COMMAND_INVALIDATE)) {
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if (unlikely(verbose_request))
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printk(KERN_DEBUG
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DRV_NAME ": %s: disable memory-write-invalidate\n",
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pci_name(dev));
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pci_clear_mwi(dev);
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}
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cmd->val = value;
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if (!xen_pcibk_permissive && (!dev_data || !dev_data->permissive))
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return 0;
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/* Only allow the guest to control certain bits. */
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err = pci_read_config_word(dev, offset, &val);
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if (err || val == value)
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return err;
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value &= PCI_COMMAND_GUEST;
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value |= val & ~PCI_COMMAND_GUEST;
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return pci_write_config_word(dev, offset, value);
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}
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static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
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{
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struct pci_bar_info *bar = data;
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if (unlikely(!bar)) {
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pr_warn(DRV_NAME ": driver data not found for %s\n",
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pci_name(dev));
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return XEN_PCI_ERR_op_failed;
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}
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/* A write to obtain the length must happen as a 32-bit write.
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* This does not (yet) support writing individual bytes
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*/
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if (value == ~PCI_ROM_ADDRESS_ENABLE)
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bar->which = 1;
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else {
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u32 tmpval;
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pci_read_config_dword(dev, offset, &tmpval);
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if (tmpval != bar->val && value == bar->val) {
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/* Allow restoration of bar value. */
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pci_write_config_dword(dev, offset, bar->val);
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}
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bar->which = 0;
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}
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/* Do we need to support enabling/disabling the rom address here? */
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return 0;
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}
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/* For the BARs, only allow writes which write ~0 or
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* the correct resource information
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* (Needed for when the driver probes the resource usage)
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*/
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static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
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{
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struct pci_bar_info *bar = data;
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if (unlikely(!bar)) {
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pr_warn(DRV_NAME ": driver data not found for %s\n",
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pci_name(dev));
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return XEN_PCI_ERR_op_failed;
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}
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/* A write to obtain the length must happen as a 32-bit write.
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* This does not (yet) support writing individual bytes
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*/
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if (value == ~0)
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bar->which = 1;
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else {
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u32 tmpval;
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pci_read_config_dword(dev, offset, &tmpval);
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if (tmpval != bar->val && value == bar->val) {
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/* Allow restoration of bar value. */
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pci_write_config_dword(dev, offset, bar->val);
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}
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bar->which = 0;
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}
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return 0;
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}
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static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
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{
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struct pci_bar_info *bar = data;
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if (unlikely(!bar)) {
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pr_warn(DRV_NAME ": driver data not found for %s\n",
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pci_name(dev));
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return XEN_PCI_ERR_op_failed;
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}
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*value = bar->which ? bar->len_val : bar->val;
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return 0;
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}
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static inline void read_dev_bar(struct pci_dev *dev,
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struct pci_bar_info *bar_info, int offset,
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u32 len_mask)
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{
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int pos;
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struct resource *res = dev->resource;
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if (offset == PCI_ROM_ADDRESS || offset == PCI_ROM_ADDRESS1)
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pos = PCI_ROM_RESOURCE;
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else {
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pos = (offset - PCI_BASE_ADDRESS_0) / 4;
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if (pos && ((res[pos - 1].flags & (PCI_BASE_ADDRESS_SPACE |
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PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
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(PCI_BASE_ADDRESS_SPACE_MEMORY |
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PCI_BASE_ADDRESS_MEM_TYPE_64))) {
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bar_info->val = res[pos - 1].start >> 32;
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bar_info->len_val = res[pos - 1].end >> 32;
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return;
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}
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}
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bar_info->val = res[pos].start |
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(res[pos].flags & PCI_REGION_FLAG_MASK);
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bar_info->len_val = resource_size(&res[pos]);
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}
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static void *bar_init(struct pci_dev *dev, int offset)
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{
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struct pci_bar_info *bar = kmalloc(sizeof(*bar), GFP_KERNEL);
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if (!bar)
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return ERR_PTR(-ENOMEM);
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read_dev_bar(dev, bar, offset, ~0);
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bar->which = 0;
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return bar;
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}
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static void *rom_init(struct pci_dev *dev, int offset)
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{
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struct pci_bar_info *bar = kmalloc(sizeof(*bar), GFP_KERNEL);
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if (!bar)
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return ERR_PTR(-ENOMEM);
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read_dev_bar(dev, bar, offset, ~PCI_ROM_ADDRESS_ENABLE);
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bar->which = 0;
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return bar;
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}
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static void bar_reset(struct pci_dev *dev, int offset, void *data)
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{
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struct pci_bar_info *bar = data;
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bar->which = 0;
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}
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static void bar_release(struct pci_dev *dev, int offset, void *data)
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{
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kfree(data);
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}
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static int xen_pcibk_read_vendor(struct pci_dev *dev, int offset,
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u16 *value, void *data)
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{
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*value = dev->vendor;
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return 0;
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}
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static int xen_pcibk_read_device(struct pci_dev *dev, int offset,
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u16 *value, void *data)
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{
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*value = dev->device;
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return 0;
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}
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static int interrupt_read(struct pci_dev *dev, int offset, u8 * value,
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void *data)
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{
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*value = (u8) dev->irq;
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return 0;
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}
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static int bist_write(struct pci_dev *dev, int offset, u8 value, void *data)
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{
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u8 cur_value;
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int err;
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err = pci_read_config_byte(dev, offset, &cur_value);
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if (err)
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goto out;
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if ((cur_value & ~PCI_BIST_START) == (value & ~PCI_BIST_START)
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|| value == PCI_BIST_START)
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err = pci_write_config_byte(dev, offset, value);
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out:
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return err;
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}
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static const struct config_field header_common[] = {
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{
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.offset = PCI_VENDOR_ID,
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.size = 2,
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.u.w.read = xen_pcibk_read_vendor,
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},
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{
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.offset = PCI_DEVICE_ID,
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.size = 2,
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.u.w.read = xen_pcibk_read_device,
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},
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{
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.offset = PCI_COMMAND,
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.size = 2,
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.init = command_init,
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.release = bar_release,
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.u.w.read = command_read,
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.u.w.write = command_write,
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},
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{
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.offset = PCI_INTERRUPT_LINE,
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.size = 1,
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.u.b.read = interrupt_read,
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},
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{
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.offset = PCI_INTERRUPT_PIN,
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.size = 1,
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.u.b.read = xen_pcibk_read_config_byte,
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},
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{
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/* Any side effects of letting driver domain control cache line? */
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.offset = PCI_CACHE_LINE_SIZE,
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.size = 1,
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.u.b.read = xen_pcibk_read_config_byte,
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.u.b.write = xen_pcibk_write_config_byte,
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},
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{
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.offset = PCI_LATENCY_TIMER,
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.size = 1,
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.u.b.read = xen_pcibk_read_config_byte,
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},
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{
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.offset = PCI_BIST,
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.size = 1,
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.u.b.read = xen_pcibk_read_config_byte,
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.u.b.write = bist_write,
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},
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{}
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};
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#define CFG_FIELD_BAR(reg_offset) \
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{ \
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.offset = reg_offset, \
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.size = 4, \
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.init = bar_init, \
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.reset = bar_reset, \
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.release = bar_release, \
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.u.dw.read = bar_read, \
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.u.dw.write = bar_write, \
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}
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#define CFG_FIELD_ROM(reg_offset) \
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{ \
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.offset = reg_offset, \
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.size = 4, \
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.init = rom_init, \
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.reset = bar_reset, \
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.release = bar_release, \
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.u.dw.read = bar_read, \
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.u.dw.write = rom_write, \
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}
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static const struct config_field header_0[] = {
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_2),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_3),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_4),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_5),
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CFG_FIELD_ROM(PCI_ROM_ADDRESS),
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{}
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};
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static const struct config_field header_1[] = {
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
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CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
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CFG_FIELD_ROM(PCI_ROM_ADDRESS1),
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{}
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};
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int xen_pcibk_config_header_add_fields(struct pci_dev *dev)
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{
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int err;
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err = xen_pcibk_config_add_fields(dev, header_common);
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if (err)
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goto out;
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switch (dev->hdr_type) {
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case PCI_HEADER_TYPE_NORMAL:
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err = xen_pcibk_config_add_fields(dev, header_0);
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break;
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case PCI_HEADER_TYPE_BRIDGE:
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err = xen_pcibk_config_add_fields(dev, header_1);
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break;
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default:
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err = -EINVAL;
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pr_err("%s: Unsupported header type %d!\n",
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pci_name(dev), dev->hdr_type);
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break;
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}
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out:
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return err;
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}
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