[dpdk-dev] [PATCH v26 4/6] dmadev: add multi-process support

[Chengwen Feng <fengchengwen@huawei.com>]

This patch add multi-process support for dmadev.

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Reviewed-by: Kevin Laatz <kevin.laatz@intel.com>
Reviewed-by: Conor Walsh <conor.walsh@intel.com>
---
 doc/guides/rel_notes/release_21_11.rst |   1 +
 lib/dmadev/rte_dmadev.c                | 183 ++++++++++++++++++++-----
 lib/dmadev/rte_dmadev_core.h           |   2 +-
 lib/dmadev/rte_dmadev_pmd.h            |  29 +++-
 4 files changed, 169 insertions(+), 46 deletions(-)

diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index 2953bc3e97..888f123237 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -82,6 +82,7 @@ New Features
     hardware and software DMA devices.
   * Added generic API which support a number of different DMA
     operations.
+  * Added multi-process support.
 
 * **Updated af_packet ethdev driver.**
 
diff --git a/lib/dmadev/rte_dmadev.c b/lib/dmadev/rte_dmadev.c
index 54e15817fa..7099bbb28d 100644
--- a/lib/dmadev/rte_dmadev.c
+++ b/lib/dmadev/rte_dmadev.c
@@ -19,6 +19,13 @@ static int16_t dma_devices_max;
 
 struct rte_dma_fp_object *rte_dma_fp_objs;
 struct rte_dma_dev *rte_dma_devices;
+static struct {
+	/* Hold the dev_max information of the primary process. This field is
+	 * set by the primary process and is read by the secondary process.
+	 */
+	int16_t dev_max;
+	struct rte_dma_dev_data data[0];
+} *dma_devices_shared_data;
 
 RTE_LOG_REGISTER_DEFAULT(rte_dma_logtype, INFO);
 #define RTE_DMA_LOG(level, ...) \
@@ -70,11 +77,11 @@ dma_find_free_id(void)
 {
 	int16_t i;
 
-	if (rte_dma_devices == NULL)
+	if (rte_dma_devices == NULL || dma_devices_shared_data == NULL)
 		return -1;
 
 	for (i = 0; i < dma_devices_max; i++) {
-		if (rte_dma_devices[i].state == RTE_DMA_DEV_UNUSED)
+		if (dma_devices_shared_data->data[i].dev_name[0] == '\0')
 			return i;
 	}
 
@@ -91,7 +98,7 @@ dma_find_by_name(const char *name)
 
 	for (i = 0; i < dma_devices_max; i++) {
 		if ((rte_dma_devices[i].state != RTE_DMA_DEV_UNUSED) &&
-		    (!strcmp(name, rte_dma_devices[i].dev_name)))
+		    (!strcmp(name, rte_dma_devices[i].data->dev_name)))
 			return &rte_dma_devices[i];
 	}
 
@@ -147,23 +154,71 @@ dma_dev_data_prepare(void)
 	return 0;
 }
 
+static int
+dma_shared_data_prepare(void)
+{
+	const char *mz_name = "rte_dma_dev_data";
+	const struct rte_memzone *mz;
+	size_t size;
+
+	if (dma_devices_shared_data != NULL)
+		return 0;
+
+	size = sizeof(*dma_devices_shared_data) +
+		sizeof(struct rte_dma_dev_data) * dma_devices_max;
+
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		mz = rte_memzone_reserve(mz_name, size, rte_socket_id(), 0);
+	else
+		mz = rte_memzone_lookup(mz_name);
+	if (mz == NULL)
+		return -ENOMEM;
+
+	dma_devices_shared_data = mz->addr;
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		memset(dma_devices_shared_data, 0, size);
+		dma_devices_shared_data->dev_max = dma_devices_max;
+	} else {
+		dma_devices_max = dma_devices_shared_data->dev_max;
+	}
+
+	return 0;
+}
+
 static int
 dma_data_prepare(void)
 {
 	int ret;
 
-	if (dma_devices_max == 0)
-		dma_devices_max = RTE_DMADEV_DEFAULT_MAX;
-
-	ret = dma_fp_data_prepare();
-	if (ret)
-		return ret;
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		if (dma_devices_max == 0)
+			dma_devices_max = RTE_DMADEV_DEFAULT_MAX;
+		ret = dma_fp_data_prepare();
+		if (ret)
+			return ret;
+		ret = dma_dev_data_prepare();
+		if (ret)
+			return ret;
+		ret = dma_shared_data_prepare();
+		if (ret)
+			return ret;
+	} else {
+		ret = dma_shared_data_prepare();
+		if (ret)
+			return ret;
+		ret = dma_fp_data_prepare();
+		if (ret)
+			return ret;
+		ret = dma_dev_data_prepare();
+		if (ret)
+			return ret;
+	}
 
-	return dma_dev_data_prepare();
+	return 0;
 }
 
 static struct rte_dma_dev *
-dma_allocate(const char *name, int numa_node, size_t private_data_size)
+dma_allocate_primary(const char *name, int numa_node, size_t private_data_size)
 {
 	struct rte_dma_dev *dev;
 	void *dev_private;
@@ -197,12 +252,59 @@ dma_allocate(const char *name, int numa_node, size_t private_data_size)
 	}
 
 	dev = &rte_dma_devices[dev_id];
-	rte_strscpy(dev->dev_name, name, sizeof(dev->dev_name));
-	dev->dev_id = dev_id;
-	dev->numa_node = numa_node;
-	dev->dev_private = dev_private;
-	dev->fp_obj = &rte_dma_fp_objs[dev_id];
-	dma_fp_object_dummy(dev->fp_obj);
+	dev->data = &dma_devices_shared_data->data[dev_id];
+	rte_strscpy(dev->data->dev_name, name, sizeof(dev->data->dev_name));
+	dev->data->dev_id = dev_id;
+	dev->data->numa_node = numa_node;
+	dev->data->dev_private = dev_private;
+
+	return dev;
+}
+
+static struct rte_dma_dev *
+dma_attach_secondary(const char *name)
+{
+	struct rte_dma_dev *dev;
+	int16_t i;
+	int ret;
+
+	ret = dma_data_prepare();
+	if (ret < 0) {
+		RTE_DMA_LOG(ERR, "Cannot initialize dmadevs data");
+		return NULL;
+	}
+
+	for (i = 0; i < dma_devices_max; i++) {
+		if (!strcmp(dma_devices_shared_data->data[i].dev_name, name))
+			break;
+	}
+	if (i == dma_devices_max) {
+		RTE_DMA_LOG(ERR,
+			"Device %s is not driven by the primary process",
+			name);
+		return NULL;
+	}
+
+	dev = &rte_dma_devices[i];
+	dev->data = &dma_devices_shared_data->data[i];
+
+	return dev;
+}
+
+static struct rte_dma_dev *
+dma_allocate(const char *name, int numa_node, size_t private_data_size)
+{
+	struct rte_dma_dev *dev;
+
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		dev = dma_allocate_primary(name, numa_node, private_data_size);
+	else
+		dev = dma_attach_secondary(name);
+
+	if (dev) {
+		dev->fp_obj = &rte_dma_fp_objs[dev->data->dev_id];
+		dma_fp_object_dummy(dev->fp_obj);
+	}
 
 	return dev;
 }
@@ -210,7 +312,11 @@ dma_allocate(const char *name, int numa_node, size_t private_data_size)
 static void
 dma_release(struct rte_dma_dev *dev)
 {
-	rte_free(dev->dev_private);
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		rte_free(dev->data->dev_private);
+		memset(dev->data, 0, sizeof(struct rte_dma_dev_data));
+	}
+
 	dma_fp_object_dummy(dev->fp_obj);
 	memset(dev, 0, sizeof(struct rte_dma_dev));
 }
@@ -245,7 +351,7 @@ rte_dma_pmd_release(const char *name)
 		return -EINVAL;
 
 	if (dev->state == RTE_DMA_DEV_READY)
-		return rte_dma_close(dev->dev_id);
+		return rte_dma_close(dev->data->dev_id);
 
 	dma_release(dev);
 	return 0;
@@ -263,7 +369,7 @@ rte_dma_get_dev_id_by_name(const char *name)
 	if (dev == NULL)
 		return -EINVAL;
 
-	return dev->dev_id;
+	return dev->data->dev_id;
 }
 
 bool
@@ -307,9 +413,9 @@ rte_dma_info_get(int16_t dev_id, struct rte_dma_info *dev_info)
 	if (ret != 0)
 		return ret;
 
-	dev_info->dev_name = dev->dev_name;
+	dev_info->dev_name = dev->data->dev_name;
 	dev_info->numa_node = dev->device->numa_node;
-	dev_info->nb_vchans = dev->dev_conf.nb_vchans;
+	dev_info->nb_vchans = dev->data->dev_conf.nb_vchans;
 
 	return 0;
 }
@@ -324,7 +430,7 @@ rte_dma_configure(int16_t dev_id, const struct rte_dma_conf *dev_conf)
 	if (!rte_dma_is_valid(dev_id) || dev_conf == NULL)
 		return -EINVAL;
 
-	if (dev->dev_started != 0) {
+	if (dev->data->dev_started != 0) {
 		RTE_DMA_LOG(ERR,
 			"Device %d must be stopped to allow configuration",
 			dev_id);
@@ -356,7 +462,8 @@ rte_dma_configure(int16_t dev_id, const struct rte_dma_conf *dev_conf)
 	ret = (*dev->dev_ops->dev_configure)(dev, dev_conf,
 					     sizeof(struct rte_dma_conf));
 	if (ret == 0)
-		memcpy(&dev->dev_conf, dev_conf, sizeof(struct rte_dma_conf));
+		memcpy(&dev->data->dev_conf, dev_conf,
+		       sizeof(struct rte_dma_conf));
 
 	return ret;
 }
@@ -370,12 +477,12 @@ rte_dma_start(int16_t dev_id)
 	if (!rte_dma_is_valid(dev_id))
 		return -EINVAL;
 
-	if (dev->dev_conf.nb_vchans == 0) {
+	if (dev->data->dev_conf.nb_vchans == 0) {
 		RTE_DMA_LOG(ERR, "Device %d must be configured first", dev_id);
 		return -EINVAL;
 	}
 
-	if (dev->dev_started != 0) {
+	if (dev->data->dev_started != 0) {
 		RTE_DMA_LOG(WARNING, "Device %d already started", dev_id);
 		return 0;
 	}
@@ -388,7 +495,7 @@ rte_dma_start(int16_t dev_id)
 		return ret;
 
 mark_started:
-	dev->dev_started = 1;
+	dev->data->dev_started = 1;
 	return 0;
 }
 
@@ -401,7 +508,7 @@ rte_dma_stop(int16_t dev_id)
 	if (!rte_dma_is_valid(dev_id))
 		return -EINVAL;
 
-	if (dev->dev_started == 0) {
+	if (dev->data->dev_started == 0) {
 		RTE_DMA_LOG(WARNING, "Device %d already stopped", dev_id);
 		return 0;
 	}
@@ -414,7 +521,7 @@ rte_dma_stop(int16_t dev_id)
 		return ret;
 
 mark_stopped:
-	dev->dev_started = 0;
+	dev->data->dev_started = 0;
 	return 0;
 }
 
@@ -428,7 +535,7 @@ rte_dma_close(int16_t dev_id)
 		return -EINVAL;
 
 	/* Device must be stopped before it can be closed */
-	if (dev->dev_started == 1) {
+	if (dev->data->dev_started == 1) {
 		RTE_DMA_LOG(ERR,
 			"Device %d must be stopped before closing", dev_id);
 		return -EBUSY;
@@ -454,7 +561,7 @@ rte_dma_vchan_setup(int16_t dev_id, uint16_t vchan,
 	if (!rte_dma_is_valid(dev_id) || conf == NULL)
 		return -EINVAL;
 
-	if (dev->dev_started != 0) {
+	if (dev->data->dev_started != 0) {
 		RTE_DMA_LOG(ERR,
 			"Device %d must be stopped to allow configuration",
 			dev_id);
@@ -466,7 +573,7 @@ rte_dma_vchan_setup(int16_t dev_id, uint16_t vchan,
 		RTE_DMA_LOG(ERR, "Device %d get device info fail", dev_id);
 		return -EINVAL;
 	}
-	if (dev->dev_conf.nb_vchans == 0) {
+	if (dev->data->dev_conf.nb_vchans == 0) {
 		RTE_DMA_LOG(ERR, "Device %d must be configured first", dev_id);
 		return -EINVAL;
 	}
@@ -540,7 +647,7 @@ rte_dma_stats_get(int16_t dev_id, uint16_t vchan, struct rte_dma_stats *stats)
 	if (!rte_dma_is_valid(dev_id) || stats == NULL)
 		return -EINVAL;
 
-	if (vchan >= dev->dev_conf.nb_vchans &&
+	if (vchan >= dev->data->dev_conf.nb_vchans &&
 	    vchan != RTE_DMA_ALL_VCHAN) {
 		RTE_DMA_LOG(ERR,
 			"Device %d vchan %u out of range", dev_id, vchan);
@@ -561,7 +668,7 @@ rte_dma_stats_reset(int16_t dev_id, uint16_t vchan)
 	if (!rte_dma_is_valid(dev_id))
 		return -EINVAL;
 
-	if (vchan >= dev->dev_conf.nb_vchans &&
+	if (vchan >= dev->data->dev_conf.nb_vchans &&
 	    vchan != RTE_DMA_ALL_VCHAN) {
 		RTE_DMA_LOG(ERR,
 			"Device %d vchan %u out of range", dev_id, vchan);
@@ -634,14 +741,14 @@ rte_dma_dump(int16_t dev_id, FILE *f)
 	}
 
 	(void)fprintf(f, "DMA Dev %d, '%s' [%s]\n",
-		dev->dev_id,
-		dev->dev_name,
-		dev->dev_started ? "started" : "stopped");
+		dev->data->dev_id,
+		dev->data->dev_name,
+		dev->data->dev_started ? "started" : "stopped");
 	dma_dump_capability(f, dev_info.dev_capa);
 	(void)fprintf(f, "  max_vchans_supported: %u\n", dev_info.max_vchans);
 	(void)fprintf(f, "  nb_vchans_configured: %u\n", dev_info.nb_vchans);
 	(void)fprintf(f, "  silent_mode: %s\n",
-		dev->dev_conf.enable_silent ? "on" : "off");
+		dev->data->dev_conf.enable_silent ? "on" : "off");
 
 	if (dev->dev_ops->dev_dump != NULL)
 		return (*dev->dev_ops->dev_dump)(dev, f);
diff --git a/lib/dmadev/rte_dmadev_core.h b/lib/dmadev/rte_dmadev_core.h
index a6946052db..236d9d38e5 100644
--- a/lib/dmadev/rte_dmadev_core.h
+++ b/lib/dmadev/rte_dmadev_core.h
@@ -60,7 +60,7 @@ typedef uint16_t (*rte_dma_completed_status_t)(void *dev_private,
  */
 struct rte_dma_fp_object {
 	/** PMD-specific private data. The driver should copy
-	 * rte_dma_dev.dev_private to this field during initialization.
+	 * rte_dma_dev.data->dev_private to this field during initialization.
 	 */
 	void *dev_private;
 	rte_dma_copy_t             copy;
diff --git a/lib/dmadev/rte_dmadev_pmd.h b/lib/dmadev/rte_dmadev_pmd.h
index d6d2161306..23b07a4e1c 100644
--- a/lib/dmadev/rte_dmadev_pmd.h
+++ b/lib/dmadev/rte_dmadev_pmd.h
@@ -76,6 +76,27 @@ struct rte_dma_dev_ops {
 
 	rte_dma_dump_t             dev_dump;
 };
+
+/**
+ * @internal
+ * The data part, with no function pointers, associated with each DMA device.
+ *
+ * This structure is safe to place in shared memory to be common among different
+ * processes in a multi-process configuration.
+ *
+ * @see struct rte_dma_dev::data
+ */
+struct rte_dma_dev_data {
+	char dev_name[RTE_DEV_NAME_MAX_LEN]; /**< Unique identifier name */
+	int16_t dev_id; /**< Device [external] identifier. */
+	int16_t numa_node; /**< Local NUMA memory ID. -1 if unknown. */
+	void *dev_private; /**< PMD-specific private data. */
+	struct rte_dma_conf dev_conf; /**< DMA device configuration. */
+	__extension__
+	uint8_t dev_started : 1; /**< Device state: STARTED(1)/STOPPED(0). */
+	uint64_t reserved[2]; /**< Reserved for future fields */
+} __rte_cache_aligned;
+
 /**
  * Possible states of a DMA device.
  *
@@ -94,20 +115,14 @@ enum rte_dma_dev_state {
  * The generic data structure associated with each DMA device.
  */
 struct rte_dma_dev {
-	char dev_name[RTE_DEV_NAME_MAX_LEN]; /**< Unique identifier name */
-	int16_t dev_id; /**< Device [external] identifier. */
-	int16_t numa_node; /**< Local NUMA memory ID. -1 if unknown. */
-	void *dev_private; /**< PMD-specific private data. */
 	/** Device info which supplied during device initialization. */
 	struct rte_device *device;
+	struct rte_dma_dev_data *data; /**< Pointer to shared device data. */
 	/**< Fast-path functions and related data. */
 	struct rte_dma_fp_object *fp_obj;
 	/** Functions implemented by PMD. */
 	const struct rte_dma_dev_ops *dev_ops;
-	struct rte_dma_conf dev_conf; /**< DMA device configuration. */
 	enum rte_dma_dev_state state; /**< Flag indicating the device state. */
-	__extension__
-	uint8_t dev_started : 1; /**< Device state: STARTED(1)/STOPPED(0). */
 	uint64_t reserved[2]; /**< Reserved for future fields. */
 } __rte_cache_aligned;
 
-- 
2.33.0