[RFC PATCH 2/5] mempool: driver for mempools of mbufs on shared memory

[Bruce Richardson <bruce.richardson@intel.com>]

This mempool driver can be used with the shared_mem bus driver to create
a pool of shared mbufs on a shared memory segment.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/mempool/meson.build                |  1 +
 drivers/mempool/shared_mem/meson.build     | 10 +++
 drivers/mempool/shared_mem/shared_mem_mp.c | 94 ++++++++++++++++++++++
 3 files changed, 105 insertions(+)
 create mode 100644 drivers/mempool/shared_mem/meson.build
 create mode 100644 drivers/mempool/shared_mem/shared_mem_mp.c

diff --git a/drivers/mempool/meson.build b/drivers/mempool/meson.build
index dc88812585..4326bd0ea3 100644
--- a/drivers/mempool/meson.build
+++ b/drivers/mempool/meson.build
@@ -8,6 +8,7 @@ drivers = [
         'dpaa2',
         'octeontx',
         'ring',
+        'shared_mem',
         'stack',
 ]
 
diff --git a/drivers/mempool/shared_mem/meson.build b/drivers/mempool/shared_mem/meson.build
new file mode 100644
index 0000000000..ee740ccdc9
--- /dev/null
+++ b/drivers/mempool/shared_mem/meson.build
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2023 Intel Corporation
+
+if is_windows
+    build = false
+    reason = 'not supported on Windows'
+endif
+sources = files('shared_mem_mp.c')
+require_iova_in_mbuf = false
+deps += ['stack', 'bus_shared_mem']
diff --git a/drivers/mempool/shared_mem/shared_mem_mp.c b/drivers/mempool/shared_mem/shared_mem_mp.c
new file mode 100644
index 0000000000..7dae8aba92
--- /dev/null
+++ b/drivers/mempool/shared_mem/shared_mem_mp.c
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2023 Intel Corporation
+ */
+#include <sys/types.h>
+#include <rte_mbuf.h>
+#include <rte_stack.h>
+#include <rte_mempool.h>
+#include <shared_mem_bus.h>
+
+RTE_LOG_REGISTER_DEFAULT(shared_mem_mp_log, DEBUG);
+#define MP_LOG(level, fmt, args...) rte_log(RTE_LOG_ ## level, \
+		shared_mem_mp_log, "## SHARED MP: %s(): " fmt "\n", __func__, ##args)
+#define MP_ERR(fmt, args...)  MP_LOG(ERR, fmt, ## args)
+#define MP_INFO(fmt, args...)  MP_LOG(INFO, fmt, ## args)
+#define MP_DEBUG(fmt, args...)  MP_LOG(DEBUG, fmt, ## args)
+
+static int
+shm_mp_alloc(struct rte_mempool *mp)
+{
+	char name[RTE_STACK_NAMESIZE];
+	struct rte_stack *s;
+	int ret;
+
+	ret = snprintf(name, sizeof(name), RTE_MEMPOOL_MZ_FORMAT, mp->name);
+	if (ret < 0 || ret >= (int)sizeof(name)) {
+		rte_errno = ENAMETOOLONG;
+		return -rte_errno;
+	}
+
+	s = rte_stack_create(name, mp->size, mp->socket_id, 0);
+	if (s == NULL)
+		return -rte_errno;
+	MP_DEBUG("Stack created at address: %p", s);
+
+	mp->pool_data = s;
+
+	return 0;
+}
+
+static int
+shm_mp_enqueue(struct rte_mempool *mp, void * const *obj_table,
+	      unsigned int n)
+{
+	struct rte_stack *s = mp->pool_data;
+
+	void *offset_table[n];
+	uintptr_t mempool_base = (uintptr_t)rte_shm_bus_get_mem_ptr(0); /* offset 0 == base addr */
+	for (uint i = 0; i < n; i++)
+		offset_table[i] = RTE_PTR_SUB(obj_table[i], mempool_base);
+
+	return rte_stack_push(s, offset_table, n) == 0 ? -ENOBUFS : 0;
+}
+
+static int
+shm_mp_dequeue(struct rte_mempool *mp, void **obj_table,
+	      unsigned int n)
+{
+	struct rte_stack *s = mp->pool_data;
+	uintptr_t mempool_base = (uintptr_t)rte_shm_bus_get_mem_ptr(0); /* offset 0 == base addr */
+	uint16_t priv_size = rte_pktmbuf_priv_size(mp);
+
+	if (rte_stack_pop(s, obj_table, n) == 0)
+		return -ENOBUFS;
+	for (uint i = 0; i < n; i++) {
+		obj_table[i] = RTE_PTR_ADD(obj_table[i], mempool_base);
+		struct rte_mbuf *mb = obj_table[i];
+		mb->buf_addr = RTE_PTR_ADD(mb, sizeof(struct rte_mbuf) + priv_size);
+		mb->pool = mp;
+	}
+	return 0;
+}
+
+static unsigned
+shm_mp_get_count(const struct rte_mempool *mp)
+{
+	return rte_stack_count(mp->pool_data);
+}
+
+static void
+shm_mp_free(struct rte_mempool *mp)
+{
+	rte_stack_free(mp->pool_data);
+}
+
+static struct rte_mempool_ops ops_shared_mem_mp = {
+	.name = "shared_mem",
+	.alloc = shm_mp_alloc,
+	.free = shm_mp_free,
+	.enqueue = shm_mp_enqueue,
+	.dequeue = shm_mp_dequeue,
+	.get_count = shm_mp_get_count,
+};
+
+RTE_MEMPOOL_REGISTER_OPS(ops_shared_mem_mp);
-- 
2.39.2