[dpdk-dev] [PATCH v2 4/6] bus/mlx5_pci: register a PCI driver

[Parav Pandit <parav@mellanox.com>]

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@mellanox.com>
---
Changelog:
v1->v2:
 - Address comments from Thomas and Gaetan
 - Enhanced driver to honor RTE_PCI_DRV_PROBE_AGAIN drv_flag
 - Use anonymous structure for class search and code changes around it
 - Define static for class comination array
 - Use RTE_DIM to find array size
 - Added OOM check for strdup()
 - Renamed copy variable to nstr_orig
 - Returning negagive error code
 - Returning directly if match entry found
 - Use compat condition check
 - Avoided cutting error message string
 - USe uint32_t datatype instead of enum mlx5_class
 - Changed logic to parse device arguments only once during probe()
 - Added check to fail driver probe if multiple classes register with
   DMA ops
 - Renamed function to parse_class_options
---
 drivers/bus/mlx5_pci/Makefile           |   2 +
 drivers/bus/mlx5_pci/meson.build        |   2 +-
 drivers/bus/mlx5_pci/mlx5_pci_bus.c     | 290 ++++++++++++++++++++++++
 drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h |   1 +
 4 files changed, 294 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mlx5_pci/Makefile b/drivers/bus/mlx5_pci/Makefile
index 7db977ba8..e53ed8856 100644
--- a/drivers/bus/mlx5_pci/Makefile
+++ b/drivers/bus/mlx5_pci/Makefile
@@ -13,7 +13,9 @@ CFLAGS += $(WERROR_FLAGS)
 CFLAGS += -I$(RTE_SDK)/drivers/common/mlx5
 CFLAGS += -I$(BUILDDIR)/drivers/common/mlx5
 CFLAGS += -I$(RTE_SDK)/drivers/bus/pci
+CFLAGS += -D_DEFAULT_SOURCE
 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..e8f1649a3 100644
--- a/drivers/bus/mlx5_pci/mlx5_pci_bus.c
+++ b/drivers/bus/mlx5_pci/mlx5_pci_bus.c
@@ -3,12 +3,302 @@
  */
 
 #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);
 
+static const struct {
+	const char *name;
+	unsigned int dev_class;
+} mlx5_classes[] = {
+	{ .name = "vdpa", .dev_class = MLX5_CLASS_VDPA },
+	{ .name = "net", .dev_class = MLX5_CLASS_NET },
+};
+
+static const unsigned int mlx5_valid_class_combo[] = {
+	MLX5_CLASS_NET,
+	MLX5_CLASS_VDPA,
+	/* New class combination should be added here */
+};
+
+static int class_name_to_val(const char *class_name)
+{
+	unsigned int i;
+
+	for (i = 0; i < RTE_DIM(mlx5_classes); i++) {
+		if (strcmp(class_name, mlx5_classes[i].name) == 0)
+			return mlx5_classes[i].dev_class;
+
+	}
+	return -EINVAL;
+}
+
+static int
+mlx5_bus_opt_handler(__rte_unused const char *key, const char *class_names,
+		     void *opaque)
+{
+	int *ret = opaque;
+	char *nstr_org;
+	int class_val;
+	char *found;
+	char *nstr;
+
+	*ret = 0;
+	nstr = strdup(class_names);
+	if (!nstr) {
+		*ret = -ENOMEM;
+		return *ret;
+	}
+
+	nstr_org = nstr;
+	while (nstr) {
+		/* Extract each individual class name */
+		found = strsep(&nstr, ":");
+		if (!found)
+			continue;
+
+		/* Check if its a valid class */
+		class_val = class_name_to_val(found);
+		if (class_val < 0) {
+			*ret = -EINVAL;
+			goto err;
+		}
+
+		*ret |= class_val;
+	}
+err:
+	free(nstr_org);
+	if (*ret < 0)
+		DRV_LOG(ERR, "Invalid mlx5 class options %s. Maybe typo in device class argument setting?",
+			class_names);
+	return *ret;
+}
+
+static int
+parse_class_options(const struct rte_devargs *devargs)
+{
+	const char *key = MLX5_CLASS_ARG_NAME;
+	struct rte_kvargs *kvlist;
+	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->pci_driver.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;
+}
+
+static int is_valid_class_combo(uint32_t user_classes)
+{
+	unsigned int i;
+
+	/* Verify if user specified valid supported combination */
+	for (i = 0; i < RTE_DIM(mlx5_valid_class_combo); i++) {
+		if (mlx5_valid_class_combo[i] == user_classes)
+			return 0;
+	}
+	/* Not found any valid class combination */
+	return -EINVAL;
+}
+
+static int validate_single_class_dma_ops(void)
+{
+	struct rte_mlx5_pci_driver *class;
+	int dma_map_classes = 0;
+
+	TAILQ_FOREACH(class, &drv_list, next) {
+		if (class->pci_driver.dma_map)
+			dma_map_classes++;
+	}
+	if (dma_map_classes > 1) {
+		DRV_LOG(ERR, "Multiple classes with DMA ops is unsupported");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ * 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;
+	uint32_t user_classes = 0;
+	int ret;
+
+	ret = validate_single_class_dma_ops();
+	if (ret)
+		return ret;
+
+	ret = parse_class_options(dev->device.devargs);
+	if (ret < 0)
+		return ret;
+
+	user_classes = ret;
+	if (user_classes) {
+		/* Validate combination here */
+		ret = is_valid_class_combo(user_classes);
+		if (ret) {
+			DRV_LOG(ERR, "Unsupported mlx5 classes supplied");
+			return ret;
+		}
+	}
+
+	/* Default to net class */
+	if (user_classes == 0)
+		user_classes = MLX5_CLASS_NET;
+
+	TAILQ_FOREACH(class, &drv_list, next) {
+		if (!mlx5_bus_match(class, dev))
+			continue;
+
+		if ((class->dev_class & user_classes) == 0)
+			continue;
+
+		ret = -EINVAL;
+		if (class->loaded) {
+			/* If already loaded and class driver can handle
+			 * reprobe, probe such class driver again.
+			 */
+			if (class->pci_driver.drv_flags & RTE_PCI_DRV_PROBE_AGAIN)
+				ret = class->pci_driver.probe(drv, dev);
+		} else {
+			ret = class->pci_driver.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 (class->loaded)
+			class->pci_driver.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->pci_driver.dma_map)
+			continue;
+
+		return class->pci_driver.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->pci_driver.dma_unmap)
+			continue;
+
+		return class->pci_driver.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 571f7dfd6..c8cd7187b 100644
--- a/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
+++ b/drivers/bus/mlx5_pci/rte_bus_mlx5_pci.h
@@ -55,6 +55,7 @@ struct rte_mlx5_pci_driver {
 	enum mlx5_class dev_class;		/**< Class of this driver */
 	struct rte_pci_driver pci_driver;	/**< Inherit core pci driver. */
 	TAILQ_ENTRY(rte_mlx5_pci_driver) next;
+	bool loaded;
 };
 
 /**
-- 
2.25.4