This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / xen / pciback / pciback_ops.c

diff --git a/drivers/xen/pciback/pciback_ops.c b/drivers/xen/pciback/pciback_ops.c
new file mode 100644 (file)
index 0000000..690941b
--- /dev/null
+++ b/drivers/xen/pciback/pciback_ops.c
@@ -0,0 +1,95 @@
+/*
+ * PCI Backend Operations - respond to PCI requests from Frontend
+ *
+ *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#include <linux/module.h>
+#include <asm/bitops.h>
+#include <xen/evtchn.h>
+#include "pciback.h"
+
+int verbose_request = 0;
+module_param(verbose_request, int, 0644);
+
+/* Ensure a device is "turned off" and ready to be exported.
+ * (Also see pciback_config_reset to ensure virtual configuration space is
+ * ready to be re-exported)
+ */
+void pciback_reset_device(struct pci_dev *dev)
+{
+       u16 cmd;
+
+       /* Disable devices (but not bridges) */
+       if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
+               pci_disable_device(dev);
+
+               pci_write_config_word(dev, PCI_COMMAND, 0);
+
+               dev->is_enabled = 0;
+               dev->is_busmaster = 0;
+       } else {
+               pci_read_config_word(dev, PCI_COMMAND, &cmd);
+               if (cmd & (PCI_COMMAND_INVALIDATE)) {
+                       cmd &= ~(PCI_COMMAND_INVALIDATE);
+                       pci_write_config_word(dev, PCI_COMMAND, cmd);
+
+                       dev->is_busmaster = 0;
+               }
+       }
+}
+
+static inline void test_and_schedule_op(struct pciback_device *pdev)
+{
+       /* Check that frontend is requesting an operation and that we are not
+        * already processing a request */
+       if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
+           && !test_and_set_bit(_PDEVF_op_active, &pdev->flags))
+               schedule_work(&pdev->op_work);
+}
+
+/* Performing the configuration space reads/writes must not be done in atomic
+ * context because some of the pci_* functions can sleep (mostly due to ACPI
+ * use of semaphores). This function is intended to be called from a work
+ * queue in process context taking a struct pciback_device as a parameter */
+void pciback_do_op(void *data)
+{
+       struct pciback_device *pdev = data;
+       struct pci_dev *dev;
+       struct xen_pci_op *op = &pdev->sh_info->op;
+
+       dev = pciback_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
+
+       if (dev == NULL)
+               op->err = XEN_PCI_ERR_dev_not_found;
+       else if (op->cmd == XEN_PCI_OP_conf_read)
+               op->err = pciback_config_read(dev, op->offset, op->size,
+                                             &op->value);
+       else if (op->cmd == XEN_PCI_OP_conf_write)
+               op->err = pciback_config_write(dev, op->offset, op->size,
+                                              op->value);
+       else
+               op->err = XEN_PCI_ERR_not_implemented;
+
+       /* Tell the driver domain that we're done. */ 
+       wmb();
+       clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
+       notify_remote_via_irq(pdev->evtchn_irq);
+
+       /* Mark that we're done. */
+       smp_mb__before_clear_bit(); /* /after/ clearing PCIF_active */
+       clear_bit(_PDEVF_op_active, &pdev->flags);
+       smp_mb__after_clear_bit(); /* /before/ final check for work */
+
+       /* Check to see if the driver domain tried to start another request in
+        * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active. */
+       test_and_schedule_op(pdev);
+}
+
+irqreturn_t pciback_handle_event(int irq, void *dev_id, struct pt_regs *regs)
+{
+       struct pciback_device *pdev = dev_id;
+
+       test_and_schedule_op(pdev);
+
+       return IRQ_HANDLED;
+}