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Diffstat (limited to 'kernel/bpf/cpumap.c')
-rw-r--r--kernel/bpf/cpumap.c117
1 files changed, 55 insertions, 62 deletions
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 8ebd0fa826f8..ef49e17ae47c 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -32,14 +32,19 @@
/* General idea: XDP packets getting XDP redirected to another CPU,
* will maximum be stored/queued for one driver ->poll() call. It is
- * guaranteed that setting flush bit and flush operation happen on
+ * guaranteed that queueing the frame and the flush operation happen on
* same CPU. Thus, cpu_map_flush operation can deduct via this_cpu_ptr()
* which queue in bpf_cpu_map_entry contains packets.
*/
#define CPU_MAP_BULK_SIZE 8 /* 8 == one cacheline on 64-bit archs */
+struct bpf_cpu_map_entry;
+struct bpf_cpu_map;
+
struct xdp_bulk_queue {
void *q[CPU_MAP_BULK_SIZE];
+ struct list_head flush_node;
+ struct bpf_cpu_map_entry *obj;
unsigned int count;
};
@@ -52,6 +57,8 @@ struct bpf_cpu_map_entry {
/* XDP can run multiple RX-ring queues, need __percpu enqueue store */
struct xdp_bulk_queue __percpu *bulkq;
+ struct bpf_cpu_map *cmap;
+
/* Queue with potential multi-producers, and single-consumer kthread */
struct ptr_ring *queue;
struct task_struct *kthread;
@@ -65,23 +72,17 @@ struct bpf_cpu_map {
struct bpf_map map;
/* Below members specific for map type */
struct bpf_cpu_map_entry **cpu_map;
- unsigned long __percpu *flush_needed;
+ struct list_head __percpu *flush_list;
};
-static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu,
- struct xdp_bulk_queue *bq, bool in_napi_ctx);
-
-static u64 cpu_map_bitmap_size(const union bpf_attr *attr)
-{
- return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long);
-}
+static int bq_flush_to_queue(struct xdp_bulk_queue *bq, bool in_napi_ctx);
static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
{
struct bpf_cpu_map *cmap;
int err = -ENOMEM;
+ int ret, cpu;
u64 cost;
- int ret;
if (!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
@@ -105,23 +106,21 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
/* make sure page count doesn't overflow */
cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *);
- cost += cpu_map_bitmap_size(attr) * num_possible_cpus();
- if (cost >= U32_MAX - PAGE_SIZE)
- goto free_cmap;
- cmap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+ cost += sizeof(struct list_head) * num_possible_cpus();
/* Notice returns -EPERM on if map size is larger than memlock limit */
- ret = bpf_map_precharge_memlock(cmap->map.pages);
+ ret = bpf_map_charge_init(&cmap->map.memory, cost);
if (ret) {
err = ret;
goto free_cmap;
}
- /* A per cpu bitfield with a bit per possible CPU in map */
- cmap->flush_needed = __alloc_percpu(cpu_map_bitmap_size(attr),
- __alignof__(unsigned long));
- if (!cmap->flush_needed)
- goto free_cmap;
+ cmap->flush_list = alloc_percpu(struct list_head);
+ if (!cmap->flush_list)
+ goto free_charge;
+
+ for_each_possible_cpu(cpu)
+ INIT_LIST_HEAD(per_cpu_ptr(cmap->flush_list, cpu));
/* Alloc array for possible remote "destination" CPUs */
cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries *
@@ -132,7 +131,9 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
return &cmap->map;
free_percpu:
- free_percpu(cmap->flush_needed);
+ free_percpu(cmap->flush_list);
+free_charge:
+ bpf_map_charge_finish(&cmap->map.memory);
free_cmap:
kfree(cmap);
return ERR_PTR(err);
@@ -209,6 +210,9 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
* - RX ring dev queue index (skb_record_rx_queue)
*/
+ /* Until page_pool get SKB return path, release DMA here */
+ xdp_release_frame(xdpf);
+
/* Allow SKB to reuse area used by xdp_frame */
xdp_scrub_frame(xdpf);
@@ -332,7 +336,8 @@ static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu,
{
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
struct bpf_cpu_map_entry *rcpu;
- int numa, err;
+ struct xdp_bulk_queue *bq;
+ int numa, err, i;
/* Have map->numa_node, but choose node of redirect target CPU */
numa = cpu_to_node(cpu);
@@ -347,6 +352,11 @@ static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu,
if (!rcpu->bulkq)
goto free_rcu;
+ for_each_possible_cpu(i) {
+ bq = per_cpu_ptr(rcpu->bulkq, i);
+ bq->obj = rcpu;
+ }
+
/* Alloc queue */
rcpu->queue = kzalloc_node(sizeof(*rcpu->queue), gfp, numa);
if (!rcpu->queue)
@@ -403,7 +413,7 @@ static void __cpu_map_entry_free(struct rcu_head *rcu)
struct xdp_bulk_queue *bq = per_cpu_ptr(rcpu->bulkq, cpu);
/* No concurrent bq_enqueue can run at this point */
- bq_flush_to_queue(rcpu, bq, false);
+ bq_flush_to_queue(bq, false);
}
free_percpu(rcpu->bulkq);
/* Cannot kthread_stop() here, last put free rcpu resources */
@@ -486,6 +496,7 @@ static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value,
rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id);
if (!rcpu)
return -ENOMEM;
+ rcpu->cmap = cmap;
}
rcu_read_lock();
__cpu_map_entry_replace(cmap, key_cpu, rcpu);
@@ -512,14 +523,14 @@ static void cpu_map_free(struct bpf_map *map)
synchronize_rcu();
/* To ensure all pending flush operations have completed wait for flush
- * bitmap to indicate all flush_needed bits to be zero on _all_ cpus.
- * Because the above synchronize_rcu() ensures the map is disconnected
- * from the program we can assume no new bits will be set.
+ * list be empty on _all_ cpus. Because the above synchronize_rcu()
+ * ensures the map is disconnected from the program we can assume no new
+ * items will be added to the list.
*/
for_each_online_cpu(cpu) {
- unsigned long *bitmap = per_cpu_ptr(cmap->flush_needed, cpu);
+ struct list_head *flush_list = per_cpu_ptr(cmap->flush_list, cpu);
- while (!bitmap_empty(bitmap, cmap->map.max_entries))
+ while (!list_empty(flush_list))
cond_resched();
}
@@ -536,7 +547,7 @@ static void cpu_map_free(struct bpf_map *map)
/* bq flush and cleanup happens after RCU graze-period */
__cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */
}
- free_percpu(cmap->flush_needed);
+ free_percpu(cmap->flush_list);
bpf_map_area_free(cmap->cpu_map);
kfree(cmap);
}
@@ -588,9 +599,9 @@ const struct bpf_map_ops cpu_map_ops = {
.map_check_btf = map_check_no_btf,
};
-static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu,
- struct xdp_bulk_queue *bq, bool in_napi_ctx)
+static int bq_flush_to_queue(struct xdp_bulk_queue *bq, bool in_napi_ctx)
{
+ struct bpf_cpu_map_entry *rcpu = bq->obj;
unsigned int processed = 0, drops = 0;
const int to_cpu = rcpu->cpu;
struct ptr_ring *q;
@@ -619,6 +630,8 @@ static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu,
bq->count = 0;
spin_unlock(&q->producer_lock);
+ __list_del_clearprev(&bq->flush_node);
+
/* Feedback loop via tracepoints */
trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu);
return 0;
@@ -629,10 +642,11 @@ static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu,
*/
static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf)
{
+ struct list_head *flush_list = this_cpu_ptr(rcpu->cmap->flush_list);
struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq);
if (unlikely(bq->count == CPU_MAP_BULK_SIZE))
- bq_flush_to_queue(rcpu, bq, true);
+ bq_flush_to_queue(bq, true);
/* Notice, xdp_buff/page MUST be queued here, long enough for
* driver to code invoking us to finished, due to driver
@@ -644,6 +658,10 @@ static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf)
* operation, when completing napi->poll call.
*/
bq->q[bq->count++] = xdpf;
+
+ if (!bq->flush_node.prev)
+ list_add(&bq->flush_node, flush_list);
+
return 0;
}
@@ -663,41 +681,16 @@ int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,
return 0;
}
-void __cpu_map_insert_ctx(struct bpf_map *map, u32 bit)
-{
- struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
- unsigned long *bitmap = this_cpu_ptr(cmap->flush_needed);
-
- __set_bit(bit, bitmap);
-}
-
void __cpu_map_flush(struct bpf_map *map)
{
struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map);
- unsigned long *bitmap = this_cpu_ptr(cmap->flush_needed);
- u32 bit;
-
- /* The napi->poll softirq makes sure __cpu_map_insert_ctx()
- * and __cpu_map_flush() happen on same CPU. Thus, the percpu
- * bitmap indicate which percpu bulkq have packets.
- */
- for_each_set_bit(bit, bitmap, map->max_entries) {
- struct bpf_cpu_map_entry *rcpu = READ_ONCE(cmap->cpu_map[bit]);
- struct xdp_bulk_queue *bq;
-
- /* This is possible if entry is removed by user space
- * between xdp redirect and flush op.
- */
- if (unlikely(!rcpu))
- continue;
-
- __clear_bit(bit, bitmap);
+ struct list_head *flush_list = this_cpu_ptr(cmap->flush_list);
+ struct xdp_bulk_queue *bq, *tmp;
- /* Flush all frames in bulkq to real queue */
- bq = this_cpu_ptr(rcpu->bulkq);
- bq_flush_to_queue(rcpu, bq, true);
+ list_for_each_entry_safe(bq, tmp, flush_list, flush_node) {
+ bq_flush_to_queue(bq, true);
/* If already running, costs spin_lock_irqsave + smb_mb */
- wake_up_process(rcpu->kthread);
+ wake_up_process(bq->obj->kthread);
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 08:26:50 +0000