[RFC bpf-next v3 2/6] bpf: Pass bitwise flags to bpf_mem_alloc_init()

[Hou Tao <houtao@xxxxxxxxxxxxxxx>]

From: Hou Tao <houtao1@xxxxxxxxxx>

Extend a boolean argument to a bitwise flags argument for
bpf_mem_alloc_init(), so more new flags can be added later.

Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
 include/linux/bpf_mem_alloc.h | 8 +++++++-
 kernel/bpf/core.c             | 2 +-
 kernel/bpf/cpumask.c          | 2 +-
 kernel/bpf/hashtab.c          | 5 +++--
 kernel/bpf/memalloc.c         | 8 +++++++-
 5 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/include/linux/bpf_mem_alloc.h b/include/linux/bpf_mem_alloc.h
index 3929be5743f4..148347950e16 100644
--- a/include/linux/bpf_mem_alloc.h
+++ b/include/linux/bpf_mem_alloc.h
@@ -12,6 +12,12 @@ struct bpf_mem_alloc {
 	struct bpf_mem_caches __percpu *caches;
 	struct bpf_mem_cache __percpu *cache;
 	struct work_struct work;
+	unsigned int flags;
+};
+
+/* flags for bpf_mem_alloc_init() */
+enum {
+	BPF_MA_PERCPU = 1U << 0,
 };
 
 /* 'size != 0' is for bpf_mem_alloc which manages fixed-size objects.
@@ -21,7 +27,7 @@ struct bpf_mem_alloc {
  * Alloc and free are done with bpf_mem_{alloc,free}() and the size of
  * the returned object is given by the size argument of bpf_mem_alloc().
  */
-int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu);
+int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, unsigned int flags);
 void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma);
 
 /* kmalloc/kfree equivalent: */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 7421487422d4..5c9622e8ca34 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2773,7 +2773,7 @@ static int __init bpf_global_ma_init(void)
 {
 	int ret;
 
-	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
+	ret = bpf_mem_alloc_init(&bpf_global_ma, 0, 0);
 	bpf_global_ma_set = !ret;
 	return ret;
 }
diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 7efdf5d770ca..f40636796f75 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -445,7 +445,7 @@ static int __init cpumask_kfunc_init(void)
 		},
 	};
 
-	ret = bpf_mem_alloc_init(&bpf_cpumask_ma, sizeof(struct bpf_cpumask), false);
+	ret = bpf_mem_alloc_init(&bpf_cpumask_ma, sizeof(struct bpf_cpumask), 0);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &cpumask_kfunc_set);
 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &cpumask_kfunc_set);
 	return  ret ?: register_btf_id_dtor_kfuncs(cpumask_dtors,
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 00c253b84bf5..93009b94ac9b 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -576,12 +576,13 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 				goto free_prealloc;
 		}
 	} else {
-		err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, false);
+		err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, 0);
 		if (err)
 			goto free_map_locked;
 		if (percpu) {
 			err = bpf_mem_alloc_init(&htab->pcpu_ma,
-						 round_up(htab->map.value_size, 8), true);
+						 round_up(htab->map.value_size, 8),
+						 BPF_MA_PERCPU);
 			if (err)
 				goto free_map_locked;
 		}
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 0668bcd7c926..072102476019 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -98,6 +98,7 @@ struct bpf_mem_cache {
 	int free_cnt;
 	int low_watermark, high_watermark, batch;
 	int percpu_size;
+	unsigned int flags;
 
 	struct rcu_head rcu;
 	struct llist_head free_by_rcu;
@@ -377,13 +378,14 @@ static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu)
  * kmalloc/kfree. Max allocation size is 4096 in this case.
  * This is bpf_dynptr and bpf_kptr use case.
  */
-int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
+int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, unsigned int flags)
 {
 	static u16 sizes[NUM_CACHES] = {96, 192, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096};
 	struct bpf_mem_caches *cc, __percpu *pcc;
 	struct bpf_mem_cache *c, __percpu *pc;
 	struct obj_cgroup *objcg = NULL;
 	int cpu, i, unit_size, percpu_size = 0;
+	bool percpu = (flags & BPF_MA_PERCPU);
 
 	if (size) {
 		pc = __alloc_percpu_gfp(sizeof(*pc), 8, GFP_KERNEL);
@@ -406,9 +408,11 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
 			c->unit_size = unit_size;
 			c->objcg = objcg;
 			c->percpu_size = percpu_size;
+			c->flags = flags;
 			prefill_mem_cache(c, cpu);
 		}
 		ma->cache = pc;
+		ma->flags = flags;
 		return 0;
 	}
 
@@ -428,10 +432,12 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu)
 			c = &cc->cache[i];
 			c->unit_size = sizes[i];
 			c->objcg = objcg;
+			c->flags = flags;
 			prefill_mem_cache(c, cpu);
 		}
 	}
 	ma->caches = pcc;
+	ma->flags = flags;
 	return 0;
 }
 
-- 
2.29.2