Add infrastructure and definitions to create XFS flow tables. This
creates the new sys entry /sys/class/net/eth*/xps_dev_flow_table_cnt
Signed-off-by: Tom Herbert <t...@herbertland.com>
---
include/linux/netdevice.h | 24 +++++++++++++
net/core/net-sysfs.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 113 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9567107..60063b3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -736,6 +736,27 @@ struct xps_dev_maps {
(nr_cpu_ids * sizeof(struct xps_map *)))
#endif /* CONFIG_XPS */
+#ifdef CONFIG_XPS_FLOWS
+struct xps_dev_flow {
+ union {
+ u64 v64;
+ struct {
+ int queue_index;
+ unsigned int queue_ptr;
+ };
+ };
+};
+
+struct xps_dev_flow_table {
+ unsigned int mask;
+ struct rcu_head rcu;
+ struct xps_dev_flow flows[0];
+};
+#define XPS_DEV_FLOW_TABLE_SIZE(_num) (sizeof(struct xps_dev_flow_table) + \
+ ((_num) * sizeof(struct xps_dev_flow)))
+
+#endif /* CONFIG_XPS_FLOWS */
+
#define TC_MAX_QUEUE 16
#define TC_BITMASK 15
/* HW offloaded queuing disciplines txq count and offset maps */
@@ -1825,6 +1846,9 @@ struct net_device {
#ifdef CONFIG_XPS
struct xps_dev_maps __rcu *xps_maps;
#endif
+#ifdef CONFIG_XPS_FLOWS
+ struct xps_dev_flow_table __rcu *xps_flow_table;
+#endif
#ifdef CONFIG_NET_CLS_ACT
struct tcf_proto __rcu *egress_cl_list;
#endif
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index ab7b0b6..0d00b9c 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -503,6 +503,92 @@ static ssize_t phys_switch_id_show(struct device *dev,
}
static DEVICE_ATTR_RO(phys_switch_id);
+#ifdef CONFIG_XPS_FLOWS
+static void xps_dev_flow_table_release(struct rcu_head *rcu)
+{
+ struct xps_dev_flow_table *table = container_of(rcu,
+ struct xps_dev_flow_table, rcu);
+ vfree(table);
+}
+
+static int change_xps_dev_flow_table_cnt(struct net_device *dev,
+ unsigned long count)
+{
+ unsigned long mask;
+ struct xps_dev_flow_table *table, *old_table;
+ static DEFINE_SPINLOCK(xps_dev_flow_lock);
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (count) {
+ mask = count - 1;
+ /* mask = roundup_pow_of_two(count) - 1;
+ * without overflows...
+ */
+ while ((mask | (mask >> 1)) != mask)
+ mask |= (mask >> 1);
+ /* On 64 bit arches, must check mask fits in table->mask (u32),
+ * and on 32bit arches, must check
+ * XPS_DEV_FLOW_TABLE_SIZE(mask + 1) doesn't overflow.
+ */
+#if BITS_PER_LONG > 32
+ if (mask > (unsigned long)(u32)mask)
+ return -EINVAL;
+#else
+ if (mask > (ULONG_MAX - XPS_DEV_FLOW_TABLE_SIZE(1))
+ / sizeof(struct xps_dev_flow)) {
+ /* Enforce a limit to prevent overflow */
+ return -EINVAL;
+ }
+#endif
+ table = vmalloc(XPS_DEV_FLOW_TABLE_SIZE(mask + 1));
+ if (!table)
+ return -ENOMEM;
+
+ table->mask = mask;
+ for (count = 0; count <= mask; count++)
+ table->flows[count].queue_index = -1;
+ } else
+ table = NULL;
+
+ spin_lock(&xps_dev_flow_lock);
+ old_table = rcu_dereference_protected(dev->xps_flow_table,
+
lockdep_is_held(&xps_dev_flow_lock));
+ rcu_assign_pointer(dev->xps_flow_table, table);
+ spin_unlock(&xps_dev_flow_lock);
+
+ if (old_table)
+ call_rcu(&old_table->rcu, xps_dev_flow_table_release);
+
+ return 0;
+}
+
+static ssize_t xps_dev_flow_table_cnt_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ return netdev_store(dev, attr, buf, len, change_xps_dev_flow_table_cnt);
+}
+
+static ssize_t xps_dev_flow_table_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct net_device *netdev = to_net_dev(dev);
+ struct xps_dev_flow_table *table;
+ unsigned int cnt = 0;
+
+ rcu_read_lock();
+ table = rcu_dereference(netdev->xps_flow_table);
+ if (table)
+ cnt = table->mask + 1;
+ rcu_read_unlock();
+
+ return sprintf(buf, fmt_dec, cnt);
+}
+DEVICE_ATTR_RW(xps_dev_flow_table_cnt);
+#endif /* CONFIG_XPS_FLOWS */
+
static struct attribute *net_class_attrs[] = {
&dev_attr_netdev_group.attr,
&dev_attr_type.attr,
@@ -531,6 +617,9 @@ static struct attribute *net_class_attrs[] = {
&dev_attr_phys_port_name.attr,
&dev_attr_phys_switch_id.attr,
&dev_attr_proto_down.attr,
+#ifdef CONFIG_XPS_FLOWS
+ &dev_attr_xps_dev_flow_table_cnt.attr,
+#endif
NULL,
};
ATTRIBUTE_GROUPS(net_class);
--
2.9.3
