[dpdk-dev] [RFC PATCH 5/6] bus/mlx5_pci: register a PCI driver

[Parav Pandit]

Create a mlx5 bus driver framework for invoking drivers of
multiple classes who have registered with the mlx5_pci bus
driver.

Validate user class arguments for supported class combinations.

Signed-off-by: Parav Pandit <parav at mellanox.com>
---
 drivers/bus/mlx5_pci/Makefile           |   1 +
 drivers/bus/mlx5_pci/meson.build        |   2 +-
 drivers/bus/mlx5_pci/mlx5_pci_bus.c     | 253 ++++++++++++++++++++++++
 drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h |   1 +
 4 files changed, 256 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mlx5_pci/Makefile b/drivers/bus/mlx5_pci/Makefile
index b36916e52..327076fe4 100644
--- a/drivers/bus/mlx5_pci/Makefile
+++ b/drivers/bus/mlx5_pci/Makefile
@@ -15,6 +15,7 @@ CFLAGS += -I$(BUILDDIR)/drivers/common/mlx5
 CFLAGS += -I$(RTE_SDK)/drivers/bus/pci
 CFLAGS += -Wno-strict-prototypes
 LDLIBS += -lrte_eal
+LDLIBS += -lrte_kvargs
 LDLIBS += -lrte_common_mlx5
 LDLIBS += -lrte_pci -lrte_bus_pci
 
diff --git a/drivers/bus/mlx5_pci/meson.build b/drivers/bus/mlx5_pci/meson.build
index cc4a84e23..5111baa4e 100644
--- a/drivers/bus/mlx5_pci/meson.build
+++ b/drivers/bus/mlx5_pci/meson.build
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2020 Mellanox Technologies Ltd
 
-deps += ['pci', 'bus_pci', 'common_mlx5']
+deps += ['pci', 'bus_pci', 'common_mlx5', 'kvargs']
 install_headers('rte_bus_mlx5_pci.h')
 sources = files('mlx5_pci_bus.c')
diff --git a/drivers/bus/mlx5_pci/mlx5_pci_bus.c b/drivers/bus/mlx5_pci/mlx5_pci_bus.c
index 66db3c7b0..8108e35ea 100644
--- a/drivers/bus/mlx5_pci/mlx5_pci_bus.c
+++ b/drivers/bus/mlx5_pci/mlx5_pci_bus.c
@@ -3,12 +3,265 @@
  */
 
 #include "rte_bus_mlx5_pci.h"
+#include <mlx5_common_utils.h>
 
 static TAILQ_HEAD(mlx5_pci_bus_drv_head, rte_mlx5_pci_driver) drv_list =
 				TAILQ_HEAD_INITIALIZER(drv_list);
 
+struct class_map {
+	const char *name;
+	enum mlx5_class dev_class;
+};
+
+const struct class_map mlx5_classes[] = {
+	{ .name = "vdpa", .dev_class = MLX5_CLASS_VDPA },
+	{ .name = "net", .dev_class = MLX5_CLASS_NET },
+};
+
+static const enum mlx5_class mlx5_valid_class_combo[] = {
+	MLX5_CLASS_NET,
+	MLX5_CLASS_VDPA,
+	/* New class combination should be added here */
+};
+
+static const struct class_map *is_valid_class(const char *class_name)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(mlx5_classes) / sizeof(struct class_map);
+	     i++) {
+		if (strcmp(class_name, mlx5_classes[i].name) == 0)
+			return &mlx5_classes[i];
+
+	}
+	return NULL;
+}
+
+static int is_valid_class_combo(const char *class_names)
+{
+	enum mlx5_class user_classes = 0;
+	char *nstr = strdup(class_names);
+	const struct class_map *entry;
+	char *copy = nstr;
+	int invalid = 0;
+	unsigned int i;
+	char *found;
+
+	while (nstr) {
+		/* Extract each individual class name */
+		found = strsep(&nstr, ":");
+		if (!found)
+			continue;
+
+		/* Check if its a valid class */
+		entry = is_valid_class(found);
+		if (!entry) {
+			invalid = EINVAL;
+			break;
+		}
+		user_classes |= entry->dev_class;
+	}
+	if (copy)
+		free(copy);
+	if (invalid)
+		return invalid;
+
+	/* Verify if user specified valid supported combination */
+	for (i = 0;
+	     i < sizeof(mlx5_valid_class_combo) / sizeof(enum mlx5_class);
+	     i++) {
+		if (mlx5_valid_class_combo[i] == user_classes)
+			break;
+	}
+	/* Not found any valid class combination */
+	if (i == sizeof(mlx5_valid_class_combo) / sizeof(enum mlx5_class))
+		return -EINVAL;
+	else
+		return 0;
+}
+
+static int
+mlx5_bus_opt_handler(__rte_unused const char *key, const char *value,
+		       void *opaque)
+{
+	int *ret = opaque;
+
+	*ret = is_valid_class_combo(value);
+	if (*ret)
+		DRV_LOG(ERR, "Invalid mlx5 classes %s. Maybe typo in device"
+			" class argument setting?", value);
+	return 0;
+}
+
+static int
+mlx5_bus_options_valid(const struct rte_devargs *devargs)
+{
+	struct rte_kvargs *kvlist;
+	const char *key = MLX5_CLASS_ARG_NAME;
+	int ret = 0;
+
+	if (devargs == NULL)
+		return 0;
+	kvlist = rte_kvargs_parse(devargs->args, NULL);
+	if (kvlist == NULL)
+		return 0;
+	if (rte_kvargs_count(kvlist, key))
+		rte_kvargs_process(kvlist, key, mlx5_bus_opt_handler, &ret);
+	rte_kvargs_free(kvlist);
+	return ret;
+}
+
 void
 rte_mlx5_pci_driver_register(struct rte_mlx5_pci_driver *driver)
 {
 	TAILQ_INSERT_TAIL(&drv_list, driver, next);
 }
+
+static bool
+mlx5_bus_match(const struct rte_mlx5_pci_driver *drv,
+		 const struct rte_pci_device *pci_dev)
+{
+	const struct rte_pci_id *id_table;
+
+	for (id_table = drv->id_table; id_table->vendor_id != 0; id_table++) {
+		/* check if device's ids match the class driver's ones */
+		if (id_table->vendor_id != pci_dev->id.vendor_id &&
+				id_table->vendor_id != PCI_ANY_ID)
+			continue;
+		if (id_table->device_id != pci_dev->id.device_id &&
+				id_table->device_id != PCI_ANY_ID)
+			continue;
+		if (id_table->subsystem_vendor_id !=
+		    pci_dev->id.subsystem_vendor_id &&
+		    id_table->subsystem_vendor_id != PCI_ANY_ID)
+			continue;
+		if (id_table->subsystem_device_id !=
+		    pci_dev->id.subsystem_device_id &&
+		    id_table->subsystem_device_id != PCI_ANY_ID)
+			continue;
+		if (id_table->class_id != pci_dev->id.class_id &&
+				id_table->class_id != RTE_CLASS_ANY_ID)
+			continue;
+
+		return true;
+	}
+	return false;
+}
+
+/**
+ * DPDK callback to register to probe multiple PCI class devices.
+ *
+ * @param[in] pci_drv
+ *   PCI driver structure.
+ * @param[in] dev
+ *   PCI device information.
+ *
+ * @return
+ *   0 on success, 1 to skip this driver, a negative errno value otherwise
+ *   and rte_errno is set.
+ */
+static int
+mlx5_bus_pci_probe(struct rte_pci_driver *drv __rte_unused,
+		     struct rte_pci_device *dev)
+{
+	struct rte_mlx5_pci_driver *class;
+	int ret = 0;
+
+	ret = mlx5_bus_options_valid(dev->device.devargs);
+	if (ret)
+		return ret;
+
+	TAILQ_FOREACH(class, &drv_list, next) {
+		if (!mlx5_bus_match(class, dev))
+			continue;
+
+		if (!mlx5_class_enabled(dev->device.devargs, class->dev_class))
+			continue;
+
+		ret = class->probe(drv, dev);
+		if (!ret)
+			class->loaded = true;
+	}
+	return 0;
+}
+
+/**
+ * DPDK callback to remove one or more class devices for a PCI device.
+ *
+ * This function removes all class devices belong to a given PCI device.
+ *
+ * @param[in] pci_dev
+ *   Pointer to the PCI device.
+ *
+ * @return
+ *   0 on success, the function cannot fail.
+ */
+static int
+mlx5_bus_pci_remove(struct rte_pci_device *dev)
+{
+	struct rte_mlx5_pci_driver *class;
+
+	/* Remove each class driver in reverse order */
+	TAILQ_FOREACH_REVERSE(class, &drv_list, mlx5_pci_bus_drv_head, next) {
+		if (!mlx5_class_enabled(dev->device.devargs, class->dev_class))
+			continue;
+
+		if (class->loaded)
+			class->remove(dev);
+	}
+	return 0;
+}
+
+static int
+mlx5_bus_pci_dma_map(struct rte_pci_device *dev, void *addr,
+		     uint64_t iova, size_t len)
+{
+	struct rte_mlx5_pci_driver *class;
+	int ret = -EINVAL;
+
+	TAILQ_FOREACH(class, &drv_list, next) {
+		if (!class->dma_map)
+			continue;
+
+		return class->dma_map(dev, addr, iova, len);
+	}
+	return ret;
+}
+
+static int
+mlx5_bus_pci_dma_unmap(struct rte_pci_device *dev, void *addr,
+		       uint64_t iova, size_t len)
+{
+	struct rte_mlx5_pci_driver *class;
+	int ret = -EINVAL;
+
+	TAILQ_FOREACH_REVERSE(class, &drv_list, mlx5_pci_bus_drv_head, next) {
+		if (!class->dma_unmap)
+			continue;
+
+		return class->dma_unmap(dev, addr, iova, len);
+	}
+	return ret;
+}
+
+static const struct rte_pci_id mlx5_bus_pci_id_map[] = {
+	{
+		.vendor_id = 0
+	}
+};
+
+static struct rte_pci_driver mlx5_bus_driver = {
+	.driver = {
+		.name = "mlx5_bus_pci",
+	},
+	.id_table = mlx5_bus_pci_id_map,
+	.probe = mlx5_bus_pci_probe,
+	.remove = mlx5_bus_pci_remove,
+	.dma_map = mlx5_bus_pci_dma_map,
+	.dma_unmap = mlx5_bus_pci_dma_unmap,
+	.drv_flags = RTE_PCI_DRV_INTR_LSC | RTE_PCI_DRV_INTR_RMV |
+		     RTE_PCI_DRV_PROBE_AGAIN,
+};
+
+RTE_PMD_REGISTER_PCI(mlx5_bus, mlx5_bus_driver);
+RTE_PMD_REGISTER_PCI_TABLE(mlx5_bus, mlx5_bus_pci_id_map);
diff --git a/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h b/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
index b0423f99e..7be9a15cd 100644
--- a/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
+++ b/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
@@ -36,6 +36,7 @@ struct rte_mlx5_pci_driver {
 	pci_dma_unmap_t *dma_unmap;   /**< Class device dma unmap function. */
 	TAILQ_ENTRY(rte_mlx5_pci_driver) next;
 	const struct rte_pci_id *id_table; /**< ID table, NULL terminated. */
+	bool loaded;
 };
 
 /**
-- 
2.25.4