1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/conf_space_quirks.c b/drivers/xen/xen-pciback/conf_space_quirks.c
new file mode 100644
index 000000000..7dc281086
--- /dev/null
+++ b/drivers/xen/xen-pciback/conf_space_quirks.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Backend - Handle special overlays for broken devices.
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ * Author: Chris Bookholt <hap10@epoch.ncsc.mil>
+ */
+
+#define dev_fmt(fmt) DRV_NAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include "pciback.h"
+#include "conf_space.h"
+#include "conf_space_quirks.h"
+
+LIST_HEAD(xen_pcibk_quirks);
+static inline const struct pci_device_id *
+match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
+{
+	if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) &&
+	    (id->device == PCI_ANY_ID || id->device == dev->device) &&
+	    (id->subvendor == PCI_ANY_ID ||
+				id->subvendor == dev->subsystem_vendor) &&
+	    (id->subdevice == PCI_ANY_ID ||
+				id->subdevice == dev->subsystem_device) &&
+	    !((id->class ^ dev->class) & id->class_mask))
+		return id;
+	return NULL;
+}
+
+static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev)
+{
+	struct xen_pcibk_config_quirk *tmp_quirk;
+
+	list_for_each_entry(tmp_quirk, &xen_pcibk_quirks, quirks_list)
+		if (match_one_device(&tmp_quirk->devid, dev) != NULL)
+			goto out;
+	tmp_quirk = NULL;
+	dev_printk(KERN_DEBUG, &dev->dev,
+		   "quirk didn't match any device known\n");
+out:
+	return tmp_quirk;
+}
+
+static inline void register_quirk(struct xen_pcibk_config_quirk *quirk)
+{
+	list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks);
+}
+
+int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg)
+{
+	int ret = 0;
+	struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
+	struct config_field_entry *cfg_entry;
+
+	list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
+		if (OFFSET(cfg_entry) == reg) {
+			ret = 1;
+			break;
+		}
+	}
+	return ret;
+}
+
+int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field
+				    *field)
+{
+	int err = 0;
+
+	switch (field->size) {
+	case 1:
+		field->u.b.read = xen_pcibk_read_config_byte;
+		field->u.b.write = xen_pcibk_write_config_byte;
+		break;
+	case 2:
+		field->u.w.read = xen_pcibk_read_config_word;
+		field->u.w.write = xen_pcibk_write_config_word;
+		break;
+	case 4:
+		field->u.dw.read = xen_pcibk_read_config_dword;
+		field->u.dw.write = xen_pcibk_write_config_dword;
+		break;
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+
+	xen_pcibk_config_add_field(dev, field);
+
+out:
+	return err;
+}
+
+int xen_pcibk_config_quirks_init(struct pci_dev *dev)
+{
+	struct xen_pcibk_config_quirk *quirk;
+	int ret = 0;
+
+	quirk = kzalloc(sizeof(*quirk), GFP_KERNEL);
+	if (!quirk) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	quirk->devid.vendor = dev->vendor;
+	quirk->devid.device = dev->device;
+	quirk->devid.subvendor = dev->subsystem_vendor;
+	quirk->devid.subdevice = dev->subsystem_device;
+	quirk->devid.class = 0;
+	quirk->devid.class_mask = 0;
+	quirk->devid.driver_data = 0UL;
+
+	quirk->pdev = dev;
+
+	register_quirk(quirk);
+out:
+	return ret;
+}
+
+void xen_pcibk_config_field_free(struct config_field *field)
+{
+	kfree(field);
+}
+
+int xen_pcibk_config_quirk_release(struct pci_dev *dev)
+{
+	struct xen_pcibk_config_quirk *quirk;
+	int ret = 0;
+
+	quirk = xen_pcibk_find_quirk(dev);
+	if (!quirk) {
+		ret = -ENXIO;
+		goto out;
+	}
+
+	list_del(&quirk->quirks_list);
+	kfree(quirk);
+
+out:
+	return ret;
+}