[PATCH v2 1/6] vfio: platform: add capability to register a reset function

Eric Auger
2015-10-22T09:41:57Z

In preparation for subsequent changes in reset function lookup,
lets introduce a dynamic list of reset combos (compat string,
reset module, reset function). The list can be populated/voided with
two new functions, vfio_platform_register/unregister_reset. Those are
not yet used in this patch.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

v1 -> v2:
- reset_list becomes static
- vfio_platform_register/unregister_reset take a const char * as compat
- fix node leak
- add reset_lock to protect the reset list manipulation
- move vfio_platform_reset_node declaration in vfio_platform_common.c
---
drivers/vfio/platform/vfio_platform_common.c | 77 +++++++++++++++++++++++++++
drivers/vfio/platform/vfio_platform_private.h | 7 +++
2 files changed, 84 insertions(+)

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index e43efb5..52a4c7b 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -23,6 +23,15 @@

#include "vfio_platform_private.h"

+struct vfio_platform_reset_node {
+ struct list_head link;
+ char *compat;
+ struct module *owner;
+ vfio_platform_reset_fn_t reset;
+};
+
+static LIST_HEAD(reset_list);
+static DEFINE_MUTEX(reset_lock);
static DEFINE_MUTEX(driver_lock);

static const struct vfio_platform_reset_combo reset_lookup_table[] = {
@@ -573,3 +582,71 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
return vdev;
}
EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
+
+int vfio_platform_register_reset(struct module *reset_owner,
+ const char *compat,
+ vfio_platform_reset_fn_t reset)
+{
+ struct vfio_platform_reset_node *node, *iter;
+ bool found = false;
+
+ mutex_lock(&reset_lock);
+ list_for_each_entry(iter, &reset_list, link) {
+ if (!strcmp(iter->compat, compat)) {
+ found = true;
+ break;
+ }
+ }
+ if (found) {
+ mutex_unlock(&reset_lock);
+ return -EINVAL;
+ }
+
+ node = kmalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ mutex_unlock(&reset_lock);
+ return -ENOMEM;
+ }
+
+ node->compat = kstrdup(compat, GFP_KERNEL);
+ if (!node->compat) {
+ kfree(node);
+ mutex_unlock(&reset_lock);
+ return -ENOMEM;
+ }
+
+ node->owner = reset_owner;
+ node->reset = reset;
+
+ list_add(&node->link, &reset_list);
+ mutex_unlock(&reset_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_platform_register_reset);
+
+int vfio_platform_unregister_reset(const char *compat)
+{
+ struct vfio_platform_reset_node *iter;
+ bool found = false;
+
+ mutex_lock(&reset_lock);
+ list_for_each_entry(iter, &reset_list, link) {
+ if (!strcmp(iter->compat, compat)) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ mutex_unlock(&reset_lock);
+ return -EINVAL;
+ }
+
+ list_del(&iter->link);
+ kfree(iter->compat);
+ kfree(iter);
+ mutex_unlock(&reset_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
+
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 1c9b3d5..1fb1410 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -89,4 +89,11 @@ extern int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
unsigned start, unsigned count,
void *data);

+typedef int (*vfio_platform_reset_fn_t)(struct vfio_platform_device *vdev);
+
+extern int vfio_platform_register_reset(struct module *owner,
+ const char *compat,
+ vfio_platform_reset_fn_t reset);
+extern int vfio_platform_unregister_reset(const char *compat);
+
#endif /* VFIO_PLATFORM_PRIVATE_H */
--
1.9.1