--- /dev/null
+/*
+ * PCI Frontend Operations - Communicates with frontend
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+#include <xen/evtchn.h>
+#include "pcifront.h"
+
+static int verbose_request = 0;
+module_param(verbose_request, int, 0644);
+
+static int errno_to_pcibios_err(int errno)
+{
+ switch (errno) {
+ case XEN_PCI_ERR_success:
+ return PCIBIOS_SUCCESSFUL;
+
+ case XEN_PCI_ERR_dev_not_found:
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ case XEN_PCI_ERR_invalid_offset:
+ case XEN_PCI_ERR_op_failed:
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ case XEN_PCI_ERR_not_implemented:
+ return PCIBIOS_FUNC_NOT_SUPPORTED;
+
+ case XEN_PCI_ERR_access_denied:
+ return PCIBIOS_SET_FAILED;
+ }
+ return errno;
+}
+
+static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op)
+{
+ int err = 0;
+ struct xen_pci_op *active_op = &pdev->sh_info->op;
+ unsigned long irq_flags;
+ evtchn_port_t port = pdev->evtchn;
+ s64 ns, ns_timeout;
+ struct timeval tv;
+
+ spin_lock_irqsave(&pdev->sh_info_lock, irq_flags);
+
+ memcpy(active_op, op, sizeof(struct xen_pci_op));
+
+ /* Go */
+ wmb();
+ set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
+ notify_remote_via_evtchn(port);
+
+ /*
+ * We set a poll timeout of 3 seconds but give up on return after
+ * 2 seconds. It is better to time out too late rather than too early
+ * (in the latter case we end up continually re-executing poll() with a
+ * timeout in the past). 1s difference gives plenty of slack for error.
+ */
+ do_gettimeofday(&tv);
+ ns_timeout = timeval_to_ns(&tv) + 2 * NSEC_PER_SEC;
+
+ clear_evtchn(port);
+
+ while (test_bit(_XEN_PCIF_active,
+ (unsigned long *)&pdev->sh_info->flags)) {
+ if (HYPERVISOR_poll(&port, 1, jiffies + 3*HZ))
+ BUG();
+ clear_evtchn(port);
+ do_gettimeofday(&tv);
+ ns = timeval_to_ns(&tv);
+ if (ns > ns_timeout) {
+ dev_err(&pdev->xdev->dev,
+ "pciback not responding!!!\n");
+ clear_bit(_XEN_PCIF_active,
+ (unsigned long *)&pdev->sh_info->flags);
+ err = XEN_PCI_ERR_dev_not_found;
+ goto out;
+ }
+ }
+
+ memcpy(op, active_op, sizeof(struct xen_pci_op));
+
+ err = op->err;
+ out:
+ spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags);
+ return err;
+}
+
+/* Access to this function is spinlocked in drivers/pci/access.c */
+static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 * val)
+{
+ int err = 0;
+ struct xen_pci_op op = {
+ .cmd = XEN_PCI_OP_conf_read,
+ .domain = pci_domain_nr(bus),
+ .bus = bus->number,
+ .devfn = devfn,
+ .offset = where,
+ .size = size,
+ };
+ struct pcifront_sd *sd = bus->sysdata;
+ struct pcifront_device *pdev = pcifront_get_pdev(sd);
+
+ if (verbose_request)
+ dev_info(&pdev->xdev->dev,
+ "read dev=%04x:%02x:%02x.%01x - offset %x size %d\n",
+ pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
+ PCI_FUNC(devfn), where, size);
+
+ err = do_pci_op(pdev, &op);
+
+ if (likely(!err)) {
+ if (verbose_request)
+ dev_info(&pdev->xdev->dev, "read got back value %x\n",
+ op.value);
+
+ *val = op.value;
+ } else if (err == -ENODEV) {
+ /* No device here, pretend that it just returned 0 */
+ err = 0;
+ *val = 0;
+ }
+
+ return errno_to_pcibios_err(err);
+}
+
+/* Access to this function is spinlocked in drivers/pci/access.c */
+static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ struct xen_pci_op op = {
+ .cmd = XEN_PCI_OP_conf_write,
+ .domain = pci_domain_nr(bus),
+ .bus = bus->number,
+ .devfn = devfn,
+ .offset = where,
+ .size = size,
+ .value = val,
+ };
+ struct pcifront_sd *sd = bus->sysdata;
+ struct pcifront_device *pdev = pcifront_get_pdev(sd);
+
+ if (verbose_request)
+ dev_info(&pdev->xdev->dev,
+ "write dev=%04x:%02x:%02x.%01x - "
+ "offset %x size %d val %x\n",
+ pci_domain_nr(bus), bus->number,
+ PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val);
+
+ return errno_to_pcibios_err(do_pci_op(pdev, &op));
+}
+
+struct pci_ops pcifront_bus_ops = {
+ .read = pcifront_bus_read,
+ .write = pcifront_bus_write,
+};
+
+/* Claim resources for the PCI frontend as-is, backend won't allow changes */
+static void pcifront_claim_resource(struct pci_dev *dev, void *data)
+{
+ struct pcifront_device *pdev = data;
+ int i;
+ struct resource *r;
+
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ r = &dev->resource[i];
+
+ if (!r->parent && r->start && r->flags) {
+ dev_dbg(&pdev->xdev->dev, "claiming resource %s/%d\n",
+ pci_name(dev), i);
+ pci_claim_resource(dev, i);
+ }
+ }
+}
+
+int pcifront_scan_root(struct pcifront_device *pdev,
+ unsigned int domain, unsigned int bus)
+{
+ struct pci_bus *b;
+ struct pcifront_sd *sd = NULL;
+ struct pci_bus_entry *bus_entry = NULL;
+ int err = 0;
+
+#ifndef CONFIG_PCI_DOMAINS
+ if (domain != 0) {
+ dev_err(&pdev->xdev->dev,
+ "PCI Root in non-zero PCI Domain! domain=%d\n", domain);
+ dev_err(&pdev->xdev->dev,
+ "Please compile with CONFIG_PCI_DOMAINS\n");
+ err = -EINVAL;
+ goto err_out;
+ }
+#endif
+
+ dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n",
+ domain, bus);
+
+ bus_entry = kmalloc(sizeof(*bus_entry), GFP_KERNEL);
+ sd = kmalloc(sizeof(*sd), GFP_KERNEL);
+ if (!bus_entry || !sd) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ pcifront_init_sd(sd, domain, pdev);
+
+ b = pci_scan_bus_parented(&pdev->xdev->dev, bus,
+ &pcifront_bus_ops, sd);
+ if (!b) {
+ dev_err(&pdev->xdev->dev,
+ "Error creating PCI Frontend Bus!\n");
+ err = -ENOMEM;
+ goto err_out;
+ }
+ bus_entry->bus = b;
+
+ list_add(&bus_entry->list, &pdev->root_buses);
+
+ /* Claim resources before going "live" with our devices */
+ pci_walk_bus(b, pcifront_claim_resource, pdev);
+
+ pci_bus_add_devices(b);
+
+ return 0;
+
+ err_out:
+ kfree(bus_entry);
+ kfree(sd);
+
+ return err;
+}
+
+static void free_root_bus_devs(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ spin_lock(&pci_bus_lock);
+ while (!list_empty(&bus->devices)) {
+ dev = container_of(bus->devices.next, struct pci_dev, bus_list);
+ spin_unlock(&pci_bus_lock);
+
+ dev_dbg(&dev->dev, "removing device\n");
+ pci_remove_bus_device(dev);
+
+ spin_lock(&pci_bus_lock);
+ }
+ spin_unlock(&pci_bus_lock);
+}
+
+void pcifront_free_roots(struct pcifront_device *pdev)
+{
+ struct pci_bus_entry *bus_entry, *t;
+
+ dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n");
+
+ list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) {
+ list_del(&bus_entry->list);
+
+ free_root_bus_devs(bus_entry->bus);
+
+ kfree(bus_entry->bus->sysdata);
+
+ device_unregister(bus_entry->bus->bridge);
+ pci_remove_bus(bus_entry->bus);
+
+ kfree(bus_entry);
+ }
+}
git://git.onelab.eu / linux-2.6.git / blobdiff