Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/core/flow.c b/net/core/flow.c
new file mode 100644
index 0000000..f289570
--- /dev/null
+++ b/net/core/flow.c
@@ -0,0 +1,371 @@
+/* flow.c: Generic flow cache.
+ *
+ * Copyright (C) 2003 Alexey N. Kuznetsov (kuznet@ms2.inr.ac.ru)
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/completion.h>
+#include <linux/percpu.h>
+#include <linux/bitops.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <net/flow.h>
+#include <asm/atomic.h>
+#include <asm/semaphore.h>
+
+struct flow_cache_entry {
+ struct flow_cache_entry *next;
+ u16 family;
+ u8 dir;
+ struct flowi key;
+ u32 genid;
+ void *object;
+ atomic_t *object_ref;
+};
+
+atomic_t flow_cache_genid = ATOMIC_INIT(0);
+
+static u32 flow_hash_shift;
+#define flow_hash_size (1 << flow_hash_shift)
+static DEFINE_PER_CPU(struct flow_cache_entry **, flow_tables) = { NULL };
+
+#define flow_table(cpu) (per_cpu(flow_tables, cpu))
+
+static kmem_cache_t *flow_cachep;
+
+static int flow_lwm, flow_hwm;
+
+struct flow_percpu_info {
+ int hash_rnd_recalc;
+ u32 hash_rnd;
+ int count;
+} ____cacheline_aligned;
+static DEFINE_PER_CPU(struct flow_percpu_info, flow_hash_info) = { 0 };
+
+#define flow_hash_rnd_recalc(cpu) \
+ (per_cpu(flow_hash_info, cpu).hash_rnd_recalc)
+#define flow_hash_rnd(cpu) \
+ (per_cpu(flow_hash_info, cpu).hash_rnd)
+#define flow_count(cpu) \
+ (per_cpu(flow_hash_info, cpu).count)
+
+static struct timer_list flow_hash_rnd_timer;
+
+#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ)
+
+struct flow_flush_info {
+ atomic_t cpuleft;
+ struct completion completion;
+};
+static DEFINE_PER_CPU(struct tasklet_struct, flow_flush_tasklets) = { NULL };
+
+#define flow_flush_tasklet(cpu) (&per_cpu(flow_flush_tasklets, cpu))
+
+static void flow_cache_new_hashrnd(unsigned long arg)
+{
+ int i;
+
+ for_each_cpu(i)
+ flow_hash_rnd_recalc(i) = 1;
+
+ flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
+ add_timer(&flow_hash_rnd_timer);
+}
+
+static void __flow_cache_shrink(int cpu, int shrink_to)
+{
+ struct flow_cache_entry *fle, **flp;
+ int i;
+
+ for (i = 0; i < flow_hash_size; i++) {
+ int k = 0;
+
+ flp = &flow_table(cpu)[i];
+ while ((fle = *flp) != NULL && k < shrink_to) {
+ k++;
+ flp = &fle->next;
+ }
+ while ((fle = *flp) != NULL) {
+ *flp = fle->next;
+ if (fle->object)
+ atomic_dec(fle->object_ref);
+ kmem_cache_free(flow_cachep, fle);
+ flow_count(cpu)--;
+ }
+ }
+}
+
+static void flow_cache_shrink(int cpu)
+{
+ int shrink_to = flow_lwm / flow_hash_size;
+
+ __flow_cache_shrink(cpu, shrink_to);
+}
+
+static void flow_new_hash_rnd(int cpu)
+{
+ get_random_bytes(&flow_hash_rnd(cpu), sizeof(u32));
+ flow_hash_rnd_recalc(cpu) = 0;
+
+ __flow_cache_shrink(cpu, 0);
+}
+
+static u32 flow_hash_code(struct flowi *key, int cpu)
+{
+ u32 *k = (u32 *) key;
+
+ return (jhash2(k, (sizeof(*key) / sizeof(u32)), flow_hash_rnd(cpu)) &
+ (flow_hash_size - 1));
+}
+
+#if (BITS_PER_LONG == 64)
+typedef u64 flow_compare_t;
+#else
+typedef u32 flow_compare_t;
+#endif
+
+extern void flowi_is_missized(void);
+
+/* I hear what you're saying, use memcmp. But memcmp cannot make
+ * important assumptions that we can here, such as alignment and
+ * constant size.
+ */
+static int flow_key_compare(struct flowi *key1, struct flowi *key2)
+{
+ flow_compare_t *k1, *k1_lim, *k2;
+ const int n_elem = sizeof(struct flowi) / sizeof(flow_compare_t);
+
+ if (sizeof(struct flowi) % sizeof(flow_compare_t))
+ flowi_is_missized();
+
+ k1 = (flow_compare_t *) key1;
+ k1_lim = k1 + n_elem;
+
+ k2 = (flow_compare_t *) key2;
+
+ do {
+ if (*k1++ != *k2++)
+ return 1;
+ } while (k1 < k1_lim);
+
+ return 0;
+}
+
+void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
+ flow_resolve_t resolver)
+{
+ struct flow_cache_entry *fle, **head;
+ unsigned int hash;
+ int cpu;
+
+ local_bh_disable();
+ cpu = smp_processor_id();
+
+ fle = NULL;
+ /* Packet really early in init? Making flow_cache_init a
+ * pre-smp initcall would solve this. --RR */
+ if (!flow_table(cpu))
+ goto nocache;
+
+ if (flow_hash_rnd_recalc(cpu))
+ flow_new_hash_rnd(cpu);
+ hash = flow_hash_code(key, cpu);
+
+ head = &flow_table(cpu)[hash];
+ for (fle = *head; fle; fle = fle->next) {
+ if (fle->family == family &&
+ fle->dir == dir &&
+ flow_key_compare(key, &fle->key) == 0) {
+ if (fle->genid == atomic_read(&flow_cache_genid)) {
+ void *ret = fle->object;
+
+ if (ret)
+ atomic_inc(fle->object_ref);
+ local_bh_enable();
+
+ return ret;
+ }
+ break;
+ }
+ }
+
+ if (!fle) {
+ if (flow_count(cpu) > flow_hwm)
+ flow_cache_shrink(cpu);
+
+ fle = kmem_cache_alloc(flow_cachep, SLAB_ATOMIC);
+ if (fle) {
+ fle->next = *head;
+ *head = fle;
+ fle->family = family;
+ fle->dir = dir;
+ memcpy(&fle->key, key, sizeof(*key));
+ fle->object = NULL;
+ flow_count(cpu)++;
+ }
+ }
+
+nocache:
+ {
+ void *obj;
+ atomic_t *obj_ref;
+
+ resolver(key, family, dir, &obj, &obj_ref);
+
+ if (fle) {
+ fle->genid = atomic_read(&flow_cache_genid);
+
+ if (fle->object)
+ atomic_dec(fle->object_ref);
+
+ fle->object = obj;
+ fle->object_ref = obj_ref;
+ if (obj)
+ atomic_inc(fle->object_ref);
+ }
+ local_bh_enable();
+
+ return obj;
+ }
+}
+
+static void flow_cache_flush_tasklet(unsigned long data)
+{
+ struct flow_flush_info *info = (void *)data;
+ int i;
+ int cpu;
+
+ cpu = smp_processor_id();
+ for (i = 0; i < flow_hash_size; i++) {
+ struct flow_cache_entry *fle;
+
+ fle = flow_table(cpu)[i];
+ for (; fle; fle = fle->next) {
+ unsigned genid = atomic_read(&flow_cache_genid);
+
+ if (!fle->object || fle->genid == genid)
+ continue;
+
+ fle->object = NULL;
+ atomic_dec(fle->object_ref);
+ }
+ }
+
+ if (atomic_dec_and_test(&info->cpuleft))
+ complete(&info->completion);
+}
+
+static void flow_cache_flush_per_cpu(void *) __attribute__((__unused__));
+static void flow_cache_flush_per_cpu(void *data)
+{
+ struct flow_flush_info *info = data;
+ int cpu;
+ struct tasklet_struct *tasklet;
+
+ cpu = smp_processor_id();
+
+ tasklet = flow_flush_tasklet(cpu);
+ tasklet->data = (unsigned long)info;
+ tasklet_schedule(tasklet);
+}
+
+void flow_cache_flush(void)
+{
+ struct flow_flush_info info;
+ static DECLARE_MUTEX(flow_flush_sem);
+
+ /* Don't want cpus going down or up during this. */
+ lock_cpu_hotplug();
+ down(&flow_flush_sem);
+ atomic_set(&info.cpuleft, num_online_cpus());
+ init_completion(&info.completion);
+
+ local_bh_disable();
+ smp_call_function(flow_cache_flush_per_cpu, &info, 1, 0);
+ flow_cache_flush_tasklet((unsigned long)&info);
+ local_bh_enable();
+
+ wait_for_completion(&info.completion);
+ up(&flow_flush_sem);
+ unlock_cpu_hotplug();
+}
+
+static void __devinit flow_cache_cpu_prepare(int cpu)
+{
+ struct tasklet_struct *tasklet;
+ unsigned long order;
+
+ for (order = 0;
+ (PAGE_SIZE << order) <
+ (sizeof(struct flow_cache_entry *)*flow_hash_size);
+ order++)
+ /* NOTHING */;
+
+ flow_table(cpu) = (struct flow_cache_entry **)
+ __get_free_pages(GFP_KERNEL, order);
+ if (!flow_table(cpu))
+ panic("NET: failed to allocate flow cache order %lu\n", order);
+
+ memset(flow_table(cpu), 0, PAGE_SIZE << order);
+
+ flow_hash_rnd_recalc(cpu) = 1;
+ flow_count(cpu) = 0;
+
+ tasklet = flow_flush_tasklet(cpu);
+ tasklet_init(tasklet, flow_cache_flush_tasklet, 0);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int flow_cache_cpu(struct notifier_block *nfb,
+ unsigned long action,
+ void *hcpu)
+{
+ if (action == CPU_DEAD)
+ __flow_cache_shrink((unsigned long)hcpu, 0);
+ return NOTIFY_OK;
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static int __init flow_cache_init(void)
+{
+ int i;
+
+ flow_cachep = kmem_cache_create("flow_cache",
+ sizeof(struct flow_cache_entry),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+
+ if (!flow_cachep)
+ panic("NET: failed to allocate flow cache slab\n");
+
+ flow_hash_shift = 10;
+ flow_lwm = 2 * flow_hash_size;
+ flow_hwm = 4 * flow_hash_size;
+
+ init_timer(&flow_hash_rnd_timer);
+ flow_hash_rnd_timer.function = flow_cache_new_hashrnd;
+ flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
+ add_timer(&flow_hash_rnd_timer);
+
+ for_each_cpu(i)
+ flow_cache_cpu_prepare(i);
+
+ hotcpu_notifier(flow_cache_cpu, 0);
+ return 0;
+}
+
+module_init(flow_cache_init);
+
+EXPORT_SYMBOL(flow_cache_genid);
+EXPORT_SYMBOL(flow_cache_lookup);