Platform bus is a software bus under Linux that manages devices which
generally do not have built-in discovery mechanisms. Linux normally
learns about platform devices directly from device-tree during
boot-up phase.
Up to this point, whenever some userspace app needed control over
platform device or a range of thereof some sort of driver being
a mixture of vdev/rawdev was required.
In order to simplify this task, provide an auto-probe
experience and separate bus logic from the driver itself,
add platform bus support.
Signed-off-by: Tomasz Duszynski <tduszyn...@marvell.com>
---
drivers/bus/meson.build | 1 +
drivers/bus/platform/meson.build | 17 +
drivers/bus/platform/platform.c | 394 ++++++++++++++++++++++++
drivers/bus/platform/platform_params.c | 70 +++++
drivers/bus/platform/private.h | 47 +++
drivers/bus/platform/rte_bus_platform.h | 165 ++++++++++
drivers/bus/platform/version.map | 10 +
7 files changed, 704 insertions(+)
create mode 100644 drivers/bus/platform/meson.build
create mode 100644 drivers/bus/platform/platform.c
create mode 100644 drivers/bus/platform/platform_params.c
create mode 100644 drivers/bus/platform/private.h
create mode 100644 drivers/bus/platform/rte_bus_platform.h
create mode 100644 drivers/bus/platform/version.map
diff --git a/drivers/bus/meson.build b/drivers/bus/meson.build
index 45eab5233d..6d2520c543 100644
--- a/drivers/bus/meson.build
+++ b/drivers/bus/meson.build
@@ -7,6 +7,7 @@ drivers = [
'fslmc',
'ifpga',
'pci',
+ 'platform',
'vdev',
'vmbus',
]
diff --git a/drivers/bus/platform/meson.build b/drivers/bus/platform/meson.build
new file mode 100644
index 0000000000..b51d757a07
--- /dev/null
+++ b/drivers/bus/platform/meson.build
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(C) 2023 Marvell.
+#
+
+if not is_linux
+ build = false
+ reason = 'only supported on Linux'
+endif
+
+deps += ['kvargs']
+sources = files(
+ 'platform_params.c',
+ 'platform.c',
+)
+headers = files(
+ 'rte_bus_platform.h',
+)
diff --git a/drivers/bus/platform/platform.c b/drivers/bus/platform/platform.c
new file mode 100644
index 0000000000..d489dde7ed
--- /dev/null
+++ b/drivers/bus/platform/platform.c
@@ -0,0 +1,394 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2023 Marvell.
+ */
+
+#include <dirent.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/queue.h>
+#include <unistd.h>
+
+#include <rte_bus.h>
+#include <rte_bus_platform.h>
+#include <rte_devargs.h>
+#include <rte_errno.h>
+#include <rte_log.h>
+#include <rte_memory.h>
+#include <rte_string_fns.h>
+
+#include "eal_filesystem.h"
+#include "private.h"
+
+#define PLATFORM_BUS_DEVICES_PATH "/sys/bus/platform/devices"
+
+void
+rte_platform_register(struct rte_platform_driver *pdrv)
+{
+ TAILQ_INSERT_TAIL(&platform_bus.driver_list, pdrv, next);
+}
+
+void
+rte_platform_unregister(struct rte_platform_driver *pdrv)
+{
+ TAILQ_REMOVE(&platform_bus.driver_list, pdrv, next);
+}
+
+static int
+parse_sysfs_value(const char *path, unsigned long *val)
+{
+ if (access(path, F_OK))
+ return -1;
+
+ return eal_parse_sysfs_value(path, val);
+}
+
+static struct rte_devargs *
+device_devargs(const char *dev_name)
+{
+ struct rte_devargs *devargs;
+
+ RTE_EAL_DEVARGS_FOREACH("platform", devargs) {
+ if (!strcmp(devargs->name, dev_name))
+ return devargs;
+ }
+
+ return NULL;
+}
+
+static bool
+device_allowed(const char *dev_name)
+{
+ struct rte_devargs *devargs;
+
+ devargs = device_devargs(dev_name);
+ if (!devargs)
+ return true;
+
+ switch (platform_bus.bus.conf.scan_mode) {
+ case RTE_BUS_SCAN_UNDEFINED:
+ case RTE_BUS_SCAN_ALLOWLIST:
+ if (devargs->policy == RTE_DEV_ALLOWED)
+ return true;
+ break;
+ case RTE_BUS_SCAN_BLOCKLIST:
+ if (devargs->policy == RTE_DEV_BLOCKED)
+ return false;
+ break;
+ }
+
+ return true;
+}
+
+static struct rte_platform_driver *
+device_lookup_driver(const char *dev_name)
+{
+ struct rte_platform_driver *pdrv = NULL;
+ char buf[BUFSIZ] = { };
+ char path[PATH_MAX];
+ char *p;
+ int ret;
+
+ snprintf(path, sizeof(path), PLATFORM_BUS_DEVICES_PATH "/%s/driver",
dev_name);
+ /* save space for terminating null byte */
+ ret = readlink(path, buf, sizeof(buf) - 1);
+ if (ret <= 0)
+ return NULL;
+
+ /* last token is kernel driver name */
+ p = strrchr(buf, '/');
+ if (!p++)
+ return NULL;
+
+ FOREACH_DRIVER_ON_PLATFORM_BUS(pdrv) {
+ /* match by driver name */
+ if (!strcmp(p, pdrv->driver.name))
+ break;
+
+ /* match by driver alias */
+ if (pdrv->driver.alias) {
+ if (!strcmp(p, pdrv->driver.alias))
+ break;
+ }
+
+ /* match by device name */
+ if (!strcmp(dev_name, pdrv->driver.name))
+ break;
+ }
+
+ return pdrv;
+}
+
+static int
+device_add(const char *dev_name)
+{
+ struct rte_platform_device *pdev;
+ char path[PATH_MAX];
+ unsigned long val;
+
+ pdev = calloc(1, sizeof(*pdev));
+ if (!pdev)
+ return -ENOMEM;
+
+ strncpy(pdev->name, dev_name, RTE_DEV_NAME_MAX_LEN);
+ pdev->device.name = pdev->name;
+ pdev->device.bus = &platform_bus.bus;
+
+ snprintf(path, sizeof(path), PLATFORM_BUS_DEVICES_PATH "/%s/numa_node",
dev_name);
+ pdev->device.numa_node = parse_sysfs_value(path, &val) ?
rte_socket_id() : val;
+
+ TAILQ_INSERT_HEAD(&platform_bus.device_list, pdev, next);
+
+ PLATFORM_LOG(INFO, "adding %s to the platform devices list\n",
dev_name);
+
+ return 0;
+}
+
+static int
+platform_bus_scan(void)
+{
+ const struct dirent *ent;
+ const char *name;
+ int ret = 0;
+ DIR *dp;
+
+ if (!(dp = opendir(PLATFORM_BUS_DEVICES_PATH))) {
+ PLATFORM_LOG(INFO, "failed to open %s\n",
PLATFORM_BUS_DEVICES_PATH);
+
+ return -errno;
+ }
+
+ while ((ent = readdir(dp))) {
+ name = ent->d_name;
+
+ if (name[0] == '.')
+ continue;
+
+ if (!device_allowed(name))
+ continue;
+
+ if (!device_lookup_driver(name))
+ continue;
+
+ ret = device_add(name);
+ if (ret)
+ break;
+ }
+
+ closedir(dp);
+
+ return ret;
+}
+
+static int
+platform_probe(struct rte_platform_device *pdev)
+{
+ struct rte_platform_driver *pdrv;
+ enum rte_iova_mode iova_mode;
+ int ret;
+
+ if (!pdev)
+ return -EINVAL;
+
+ pdrv = device_lookup_driver(pdev->name);
+ if (!pdrv)
+ return -ENODEV;
+
+ iova_mode = rte_eal_iova_mode();
+ if (pdrv->drv_flags & RTE_PLATFORM_DRV_NEED_IOVA_AS_VA && iova_mode !=
RTE_IOVA_VA) {
+ PLATFORM_LOG(ERR, "Driver %s expects VA IOVA mode but current
mode is PA\n",
+ pdrv->driver.name);
+
+ return -EINVAL;
+ }
+
+ if (!pdrv->probe)
+ return -ENOTSUP;
+
+ pdev->driver = pdrv;
+
+ ret = pdrv->probe(pdev);
+ if (ret)
+ return ret;
+
+ pdev->device.driver = &pdrv->driver;
+
+ return 0;
+}
+
+static int
+platform_remove(struct rte_platform_device *pdev)
+{
+ struct rte_platform_driver *pdrv;
+ int ret;
+
+ if (!pdev)
+ return -EINVAL;
+
+ pdrv = pdev->driver;
+ if (pdrv->remove) {
+ ret = pdrv->remove(pdev);
+ if (ret)
+ return ret;
+ }
+
+ pdev->driver = NULL;
+ pdev->device.driver = NULL;
+
+ TAILQ_REMOVE(&platform_bus.device_list, pdev, next);
+ rte_devargs_remove(pdev->device.devargs);
+ free(pdrv);
+
+ return 0;
+}
+
+static int
+platform_bus_probe(void)
+{
+ struct rte_platform_device *pdev;
+ int ret;
+
+ FOREACH_DEVICE_ON_PLATFORM_BUS(pdev) {
+ ret = platform_probe(pdev);
+ if (ret)
+ PLATFORM_LOG(ERR, "failed to probe %s\n", pdev->name);
+ }
+
+ return 0;
+}
+
+static struct rte_device *
+platform_bus_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
const void *data)
+{
+ struct rte_platform_device *pdev;
+
+ pdev = start ? RTE_TAILQ_NEXT(RTE_DEV_TO_PLATFORM_DEV_CONST(start),
next) :
+ RTE_TAILQ_FIRST(&platform_bus.device_list);
+ while (pdev) {
+ if (cmp(&pdev->device, data) == 0)
+ return &pdev->device;
+
+ pdev = RTE_TAILQ_NEXT(pdev, next);
+ }
+
+ return NULL;
+}
+
+static bool
+device_exists(const char *dev_name)
+{
+ char path[PATH_MAX];
+
+ snprintf(path, sizeof(path), PLATFORM_BUS_DEVICES_PATH "/%s", dev_name);
+
+ return access(path, R_OK) == 0;
+}
+
+static int
+platform_bus_plug(struct rte_device *dev)
+{
+ if (!device_exists(dev->name))
+ return -ENODEV;
+
+ if (device_allowed(dev->name)) {
+ PLATFORM_LOG(WARNING, "Device not allowed\n");
+
+ return -ENODEV;
+ }
+
+ return platform_probe(RTE_DEV_TO_PLATFORM_DEV(dev));
+}
+
+static int
+platform_bus_unplug(struct rte_device *dev)
+{
+ struct rte_platform_device *pdev = RTE_DEV_TO_PLATFORM_DEV(dev);
+
+ return platform_remove(pdev);
+}
+
+static int
+platform_bus_parse(const char *name, void *addr)
+{
+ struct rte_platform_driver *pdrv;
+ const char **out = addr;
+
+ pdrv = device_lookup_driver(name);
+ if (pdrv && addr)
+ *out = name;
+
+ return pdrv ? 0 : -1;
+}
+
+static int
+platform_bus_dma_map(struct rte_device *dev, void *addr, uint64_t iova, size_t
len)
+{
+ struct rte_platform_device *pdev = RTE_DEV_TO_PLATFORM_DEV(dev);
+
+ if (!pdev || !pdev->driver) {
+ rte_errno = EINVAL;
+
+ return -1;
+ }
+
+ if (!pdev->driver->dma_map) {
+ rte_errno = ENOTSUP;
+
+ return -1;
+ }
+
+ return pdev->driver->dma_map(pdev, addr, iova, len);
+}
+
+static int
+platform_bus_dma_unmap(struct rte_device *dev, void *addr, uint64_t iova,
size_t len)
+{
+
+ struct rte_platform_device *pdev = RTE_DEV_TO_PLATFORM_DEV(dev);
+
+ if (!pdev || !pdev->driver) {
+ rte_errno = EINVAL;
+
+ return -1;
+ }
+
+ if (!pdev->driver->dma_unmap) {
+ rte_errno = ENOTSUP;
+
+ return -1;
+ }
+
+ return pdev->driver->dma_unmap(pdev, addr, iova, len);
+}
+
+static enum rte_iova_mode
+platform_bus_get_iommu_class(void)
+{
+ struct rte_platform_driver *pdrv;
+
+ FOREACH_DRIVER_ON_PLATFORM_BUS(pdrv) {
+ if (pdrv->drv_flags & RTE_PLATFORM_DRV_NEED_IOVA_AS_VA)
+ return RTE_IOVA_VA;
+ }
+
+ return RTE_IOVA_DC;
+}
+
+struct rte_platform_bus platform_bus = {
+ .bus = {
+ .scan = platform_bus_scan,
+ .probe = platform_bus_probe,
+ .find_device = platform_bus_find_device,
+ .plug = platform_bus_plug,
+ .unplug = platform_bus_unplug,
+ .parse = platform_bus_parse,
+ .dma_map = platform_bus_dma_map,
+ .dma_unmap = platform_bus_dma_unmap,
+ .get_iommu_class = platform_bus_get_iommu_class,
+ .dev_iterate = platform_bus_dev_iterate,
+ },
+ .device_list = TAILQ_HEAD_INITIALIZER(platform_bus.device_list),
+ .driver_list = TAILQ_HEAD_INITIALIZER(platform_bus.driver_list),
+};
+
+RTE_REGISTER_BUS(platform_bus, platform_bus.bus);
+RTE_LOG_REGISTER_DEFAULT(platform_bus_logtype, NOTICE);
diff --git a/drivers/bus/platform/platform_params.c
b/drivers/bus/platform/platform_params.c
new file mode 100644
index 0000000000..86e8587b82
--- /dev/null
+++ b/drivers/bus/platform/platform_params.c
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2023 Marvell.
+ */
+
+#include <string.h>
+
+#include <rte_bus.h>
+#include <rte_common.h>
+#include <rte_dev.h>
+#include <rte_errno.h>
+#include <rte_kvargs.h>
+
+#include "private.h"
+#include "rte_bus_platform.h"
+
+enum platform_params {
+ RTE_PLATFORM_PARAM_NAME,
+};
+
+static const char * const platform_params_keys[] = {
+ [RTE_PLATFORM_PARAM_NAME] = "name",
+ NULL
+};
+
+static int
+platform_dev_match(const struct rte_device *dev, const void *_kvlist)
+{
+ const char *key = platform_params_keys[RTE_PLATFORM_PARAM_NAME];
+ const struct rte_kvargs *kvlist = _kvlist;
+ const char *name;
+
+ /* no kvlist arg, all devices match */
+ if (!kvlist)
+ return 0;
+
+ /* if key is present in kvlist and does not match, filter device */
+ name = rte_kvargs_get(kvlist, key);
+ if (name && strcmp(name, dev->name))
+ return -1;
+
+ return 0;
+}
+
+void *
+platform_bus_dev_iterate(const void *start, const char *str,
+ const struct rte_dev_iterator *it __rte_unused)
+{
+ rte_bus_find_device_t find_device;
+ struct rte_kvargs *kvargs = NULL;
+ struct rte_device *dev;
+
+ if (str) {
+ kvargs = rte_kvargs_parse(str, platform_params_keys);
+ if (!kvargs) {
+ PLATFORM_LOG(ERR, "cannot parse argument list %s", str);
+ rte_errno = EINVAL;
+
+ return NULL;
+ }
+ }
+
+ find_device = platform_bus.bus.find_device;
+ if (!find_device)
+ return NULL;
+
+ dev = platform_bus.bus.find_device(start, platform_dev_match, kvargs);
+ rte_kvargs_free(kvargs);
+
+ return dev;
+}
diff --git a/drivers/bus/platform/private.h b/drivers/bus/platform/private.h
new file mode 100644
index 0000000000..988803080f
--- /dev/null
+++ b/drivers/bus/platform/private.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2023 Marvell.
+ */
+
+#ifndef _RTE_BUS_PLATFORM_PRIVATE_H_
+#define _RTE_BUS_PLATFORM_PRIVATE_H_
+
+#include <rte_bus.h>
+#include <rte_common.h>
+#include <rte_dev.h>
+#include <rte_log.h>
+#include <rte_os.h>
+
+#include "rte_bus_platform.h"
+
+extern struct rte_platform_bus platform_bus;
+extern int platform_bus_logtype;
+
+/* Platform bus iterators. */
+#define FOREACH_DEVICE_ON_PLATFORM_BUS(p) \
+ RTE_TAILQ_FOREACH(p, &(platform_bus.device_list), next)
+
+#define FOREACH_DRIVER_ON_PLATFORM_BUS(p) \
+ RTE_TAILQ_FOREACH(p, &(platform_bus.driver_list), next)
+
+/*
+ * Structure describing platform bus.
+ */
+struct rte_platform_bus {
+ struct rte_bus bus; /* Core bus */
+ RTE_TAILQ_HEAD(, rte_platform_device) device_list; /* List of bus
devices */
+ RTE_TAILQ_HEAD(, rte_platform_driver) driver_list; /* List of bus
drivers */
+};
+
+#define PLATFORM_LOG(level, ...) \
+ rte_log(RTE_LOG_ ## level, platform_bus_logtype, \
+ RTE_FMT("platform bus: " RTE_FMT_HEAD(__VA_ARGS__,) , \
+ RTE_FMT_TAIL(__VA_ARGS__,)))
+
+/*
+ * Iterate registered platform devices and find one that matches provided
string.
+ */
+void *
+platform_bus_dev_iterate(const void *start, const char *str,
+ const struct rte_dev_iterator *it __rte_unused);
+
+#endif /* _RTE_BUS_PLATFORM_PRIVATE_H_ */
diff --git a/drivers/bus/platform/rte_bus_platform.h
b/drivers/bus/platform/rte_bus_platform.h
new file mode 100644
index 0000000000..5e5cdb166b
--- /dev/null
+++ b/drivers/bus/platform/rte_bus_platform.h
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2023 Marvell.
+ */
+
+#ifndef _RTE_BUS_PLATFORM_H_
+#define _RTE_BUS_PLATFORM_H_
+
+/**
+ * @file
+ * Platform bus interface.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <rte_common.h>
+#include <rte_dev.h>
+#include <rte_os.h>
+
+/* Forward declarations */
+struct rte_platform_bus;
+struct rte_platform_device;
+struct rte_platform_driver;
+
+/**
+ * Initialization function for the driver called during platform device
probing.
+ *
+ * @param pdev
+ * Pointer to the platform device.
+ * @return
+ * 0 on success, negative value otherwise.
+ */
+typedef int (rte_platform_probe_t)(struct rte_platform_device *pdev);
+
+/**
+ * Removal function for the driver called during platform device removal.
+ *
+ * @param pdev
+ * Pointer to the platform device.
+ * @return
+ * 0 on success, negative value otherwise.
+ */
+typedef int (rte_platform_remove_t)(struct rte_platform_device *pdev);
+
+/**
+ * Driver specific DMA mapping.
+ *
+ * @param pdev
+ * Pointer to the platform device.
+ * @param addr
+ * Starting virtual address of memory to be mapped.
+ * @param iova
+ * Starting IOVA address of memory to be mapped.
+ * @param len
+ * Length of memory segment being mapped.
+ * @return
+ * - 0 on success.
+ * - Negative value and rte_errno is set otherwise.
+ */
+typedef int (rte_platform_dma_map_t)(struct rte_platform_device *pdev, void
*addr, uint64_t iova,
+ size_t len);
+
+/**
+ * Driver specific DMA unmapping.
+ *
+ * @param pdev
+ * Pointer to the platform device.
+ * @param addr
+ * Starting virtual address of memory to be mapped.
+ * @param iova
+ * Starting IOVA address of memory to be mapped.
+ * @param len
+ * Length of memory segment being mapped.
+ * @return
+ * - 0 on success.
+ * - Negative value and rte_errno is set otherwise.
+ */
+typedef int (rte_platform_dma_unmap_t)(struct rte_platform_device *pdev, void
*addr, uint64_t iova,
+ size_t len);
+
+/**
+ * A structure describing a platform device.
+ */
+struct rte_platform_device {
+ RTE_TAILQ_ENTRY(rte_platform_device) next; /**< Next attached platform
device */
+ struct rte_device device; /**< Core device */
+ struct rte_platform_driver *driver; /**< Matching device driver */
+ char name[RTE_DEV_NAME_MAX_LEN + 1]; /**< Device name */
+ void *driver_data; /**< Driver data */
+};
+
+/**
+ * A structure describing a platform device driver.
+ */
+struct rte_platform_driver {
+ RTE_TAILQ_ENTRY(rte_platform_driver) next; /**< Next available platform
driver */
+ struct rte_driver driver; /**< Core driver */
+ rte_platform_probe_t *probe; /**< Device probe function */
+ rte_platform_remove_t *remove; /**< Device remove function */
+ rte_platform_dma_map_t *dma_map; /**< Device DMA map function */
+ rte_platform_dma_unmap_t *dma_unmap; /**< Device DMA unmap function */
+ /** Device driver needs IOVA as VA and cannot work with IOVA as VA */
+#define RTE_PLATFORM_DRV_NEED_IOVA_AS_VA 0x0001
+ uint32_t drv_flags; /**< Driver flags */
+};
+
+/**
+ * @internal
+ * Helper macros used to convert core device to platform device.
+ */
+#define RTE_DEV_TO_PLATFORM_DEV(ptr) \
+ container_of(ptr, struct rte_platform_device, device)
+
+#define RTE_DEV_TO_PLATFORM_DEV_CONST(ptr) \
+ container_of(ptr, const struct rte_platform_device, device)
+
+/**
+ * Register a platform device driver.
+ *
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * @param pdrv
+ * A pointer to a rte_platform_driver structure describing driver to be
registered.
+ */
+__rte_experimental
+void rte_platform_register(struct rte_platform_driver *pdrv);
+
+/** Helper for platform driver registration. */
+#define RTE_PMD_REGISTER_PLATFORM(nm, platform_drv) \
+static const char *pdrvinit_ ## nm ## _alias; \
+RTE_INIT(pdrvinitfn_ ##nm) \
+{ \
+ (platform_drv).driver.name = RTE_STR(nm); \
+ (platform_drv).driver.alias = pdrvinit_ ## nm ## _alias; \
+ rte_platform_register(&(platform_drv)); \
+} \
+RTE_PMD_EXPORT_NAME(nm, __COUNTER__)
+
+/** Helper for setting platform driver alias. */
+#define RTE_PMD_REGISTER_ALIAS(nm, alias) \
+static const char *pdrvinit_ ## nm ## _alias = RTE_STR(alias)
+
+/**
+ * Unregister a platform device driver.
+ *
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * @param pdrv
+ * A pointer to a rte_platform_driver structure describing driver to be
unregistered.
+ */
+__rte_experimental
+void rte_platform_unregister(struct rte_platform_driver *pdrv);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_BUS_PLATFORM_H_ */
diff --git a/drivers/bus/platform/version.map b/drivers/bus/platform/version.map
new file mode 100644
index 0000000000..ee77a6beff
--- /dev/null
+++ b/drivers/bus/platform/version.map
@@ -0,0 +1,10 @@
+DPDK_23 {
+ local: *;
+};
+
+EXPERIMENTAL {
+ global:
+
+ rte_platform_register;
+ rte_platform_unregister;
+};
--
2.25.1
