[PATCH 3/4] drivers/bus: Device driver for FSL-MC DPRC devices

J. German Rivera
2014-09-11T17:50:49Z

From: "J. German Rivera" <German.Rivera@freescale.com>

A DPRC (Data Path Resource Container) is an isolation device
that contains a set of DPAA networking devices to be
assigned to an isolation domain (e.g., a virtual machine).

Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
---
Changes in RFC v4:
- Fixed parameter mismatch for device_find_child() call in fsl_mc_dprc.c

Changes in RFC v3:
- Removed per-bus list of children, and instead use device_for_each_child()
- Use the same structure (struct fsl_mc_device) to represent both
bus devices and their children.

Changes in RFC v2:
- Removed the 'magic' fields from all structs

drivers/bus/fsl-mc/Makefile | 3 +-
drivers/bus/fsl-mc/fsl_mc_dprc.c | 396 ++++++++++++++++++++++++++++++++++++++
include/linux/fsl_mc_private.h | 6 +
3 files changed, 404 insertions(+), 1 deletion(-)
create mode 100644 drivers/bus/fsl-mc/fsl_mc_dprc.c

diff --git a/drivers/bus/fsl-mc/Makefile b/drivers/bus/fsl-mc/Makefile
index 2981d70..499dc9b 100644
--- a/drivers/bus/fsl-mc/Makefile
+++ b/drivers/bus/fsl-mc/Makefile
@@ -5,7 +5,8 @@
#
# This file is released under the GPLv2
#
-obj-$(CONFIG_FSL_MC_BUS) += fsl_mc_bus_driver.o
+obj-$(CONFIG_FSL_MC_BUS) += fsl_mc_bus_driver.o \
+ fsl_mc_dprc.o

fsl_mc_bus_driver-objs := fsl_mc_bus.o \
fsl_mc_sys.o \
diff --git a/drivers/bus/fsl-mc/fsl_mc_dprc.c b/drivers/bus/fsl-mc/fsl_mc_dprc.c
new file mode 100644
index 0000000..c05cbef
--- /dev/null
+++ b/drivers/bus/fsl-mc/fsl_mc_dprc.c
@@ -0,0 +1,396 @@
+/*
+ * Freescale daata path resource container (DPRC) driver
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ * Author: German Rivera <German.Rivera@freescale.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/fsl_mc_private.h>
+#include <linux/fsl_mc_sys.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "fsl_dprc_cmd.h"
+
+struct dprc_child_objs {
+ int child_count;
+ struct dprc_obj_desc *child_array;
+};
+
+static int __fsl_mc_device_remove_if_not_in_mc(struct device *dev, void *data)
+{
+ int i;
+ struct dprc_child_objs *objs;
+ struct fsl_mc_device *mc_dev;
+
+ WARN_ON(dev == NULL);
+ WARN_ON(data == NULL);
+ mc_dev = to_fsl_mc_device(dev);
+ objs = data;
+
+ for (i = 0; i < objs->child_count; i++) {
+ struct dprc_obj_desc *obj_desc = &objs->child_array[i];
+
+ if (strlen(obj_desc->type) != 0 &&
+ FSL_MC_DEVICE_MATCH(mc_dev, obj_desc))
+ break;
+ }
+
+ if (i == objs->child_count)
+ fsl_mc_device_remove(mc_dev);
+
+ return 0;
+}
+
+static int __fsl_mc_device_remove(struct device *dev, void *data)
+{
+ WARN_ON(dev == NULL);
+ WARN_ON(data != NULL);
+ fsl_mc_device_remove(to_fsl_mc_device(dev));
+ return 0;
+}
+
+/**
+ * dprc_remove_devices - Removes devices for objects removed from a DPRC
+ *
+ * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ * @obj_desc_array: array of object descriptors for child objects currently
+ * present in the DPRC in the MC.
+ * @num_child_objects_in_mc: number of entries in obj_desc_array
+ *
+ * Synchronizes the state of the Linux bus driver with the actual state of
+ * the MC by removing devices that represent MC objects that have
+ * been dynamically removed in the physical DPRC.
+ */
+static void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
+ struct dprc_obj_desc *obj_desc_array,
+ int num_child_objects_in_mc)
+{
+ if (num_child_objects_in_mc != 0) {
+ /*
+ * Remove child objects that are in the DPRC in Linux,
+ * but not in the MC:
+ */
+ struct dprc_child_objs objs;
+
+ objs.child_count = num_child_objects_in_mc;
+ objs.child_array = obj_desc_array;
+ device_for_each_child(&mc_bus_dev->dev, &objs,
+ __fsl_mc_device_remove_if_not_in_mc);
+ } else {
+ /*
+ * There are no child objects for this DPRC in the MC.
+ * So, remove all the child devices from Linux:
+ */
+ device_for_each_child(&mc_bus_dev->dev, NULL,
+ __fsl_mc_device_remove);
+ }
+}
+
+static int __fsl_mc_device_match(struct device *dev, void *data)
+{
+ struct dprc_obj_desc *obj_desc = data;
+ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+
+ return FSL_MC_DEVICE_MATCH(mc_dev, obj_desc);
+}
+
+static struct fsl_mc_device *fsl_mc_device_lookup(struct dprc_obj_desc
+ *obj_desc,
+ struct fsl_mc_device
+ *mc_bus_dev)
+{
+ struct device *dev;
+
+ dev = device_find_child(&mc_bus_dev->dev, obj_desc,
+ __fsl_mc_device_match);
+
+ return (dev != NULL) ? to_fsl_mc_device(dev) : NULL;
+}
+
+/**
+ * dprc_add_new_devices - Adds devices to the logical bus for a DPRC
+ *
+ * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ * @obj_desc_array: array of device descriptors for child devices currently
+ * present in the physical DPRC.
+ * @num_child_objects_in_mc: number of entries in obj_desc_array
+ *
+ * Synchronizes the state of the Linux bus driver with the actual
+ * state of the MC by adding objects that have been newly discovered
+ * in the physical DPRC.
+ */
+static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
+ struct dprc_obj_desc *obj_desc_array,
+ int num_child_objects_in_mc)
+{
+ int error;
+ int i;
+
+ for (i = 0; i < num_child_objects_in_mc; i++) {
+ struct dprc_region_desc region_desc;
+ struct fsl_mc_device *child_dev;
+ struct fsl_mc_io *mc_io = NULL;
+ struct dprc_obj_desc *obj_desc = &obj_desc_array[i];
+
+ if (strlen(obj_desc->type) == 0)
+ continue;
+ /*
+ * Check if device is already known to Linux:
+ */
+ child_dev = fsl_mc_device_lookup(obj_desc, mc_bus_dev);
+ if (child_dev != NULL)
+ continue;
+
+ if (strcmp(obj_desc->type, "dprc") == 0) {
+ /*
+ * Get the MC portal physical address for the device
+ * (specified in the device's first MMIO region):
+ */
+ if (WARN_ON(obj_desc->region_count == 0))
+ continue;
+
+ error = dprc_get_obj_region(mc_bus_dev->mc_io,
+ mc_bus_dev->mc_handle,
+ obj_desc->type,
+ obj_desc->id,
+ 0, &region_desc);
+ if (error < 0) {
+ dev_err(&mc_bus_dev->dev,
+ "dprc_get_obj_region() failed: %d\n",
+ error);
+ continue;
+ }
+
+ if (region_desc.size !=
+ mc_bus_dev->mc_io->portal_size) {
+ error = -EINVAL;
+ dev_err(&mc_bus_dev->dev,
+ "Invalid MC portal size: %lu\n",
+ region_desc.size);
+ continue;
+ }
+
+ error = fsl_create_mc_io(region_desc.base_paddr,
+ region_desc.size, 0, &mc_io);
+ if (error < 0)
+ continue;
+ }
+
+ error = fsl_mc_device_add(obj_desc, mc_io, &mc_bus_dev->dev,
+ &child_dev);
+ if (error < 0) {
+ if (mc_io != NULL)
+ fsl_destroy_mc_io(mc_io);
+
+ continue;
+ }
+ }
+}
+
+/**
+ * dprc_scan_objects - Discover objects in a DPRC
+ *
+ * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ *
+ * Detects objects added and removed from a DPRC and synchronizes the
+ * state of the Linux bus driver, MC by adding and removing
+ * devices accordingly.
+ */
+int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev)
+{
+ int num_child_objects;
+ int dprc_get_obj_failures;
+ int error = -EINVAL;
+ struct dprc_obj_desc *child_obj_desc_array = NULL;
+
+ error = dprc_get_obj_count(mc_bus_dev->mc_io,
+ mc_bus_dev->mc_handle,
+ &num_child_objects);
+ if (error < 0) {
+ dev_err(&mc_bus_dev->dev, "dprc_get_obj_count() failed: %d\n",
+ error);
+ goto out;
+ }
+
+ if (num_child_objects != 0) {
+ int i;
+
+ child_obj_desc_array =
+ kmalloc_array(num_child_objects,
+ sizeof(*child_obj_desc_array), GFP_KERNEL);
+ if (child_obj_desc_array == NULL) {
+ error = -ENOMEM;
+ dev_err(&mc_bus_dev->dev,
+ "No memory to allocate obj_desc array\n");
+ goto out;
+ }
+
+ /*
+ * Discover objects currently present in the physical DPRC:
+ */
+ dprc_get_obj_failures = 0;
+ for (i = 0; i < num_child_objects; i++) {
+ struct dprc_obj_desc *obj_desc =
+ &child_obj_desc_array[i];
+
+ error = dprc_get_obj(mc_bus_dev->mc_io,
+ mc_bus_dev->mc_handle,
+ i, obj_desc);
+ if (error < 0) {
+ dev_err(&mc_bus_dev->dev,
+ "dprc_get_obj(i=%d) failed: %d\n",
+ i, error);
+ /*
+ * Mark the obj entry as "invalid", by using the
+ * empty string as obj type:
+ */
+ obj_desc->type[0] = '\0';
+ obj_desc->id = error;
+ dprc_get_obj_failures++;
+ continue;
+ }
+
+ dev_info(&mc_bus_dev->dev,
+ "Discovered object: type %s, id %d\n",
+ obj_desc->type, obj_desc->id);
+ }
+
+ if (dprc_get_obj_failures != 0) {
+ dev_err(&mc_bus_dev->dev,
+ "%d out of %d devices could not be retrieved\n",
+ dprc_get_obj_failures, num_child_objects);
+ }
+ }
+
+ dprc_remove_devices(mc_bus_dev, child_obj_desc_array,
+ num_child_objects);
+
+ dprc_add_new_devices(mc_bus_dev, child_obj_desc_array,
+ num_child_objects);
+
+ error = 0;
+out:
+ if (child_obj_desc_array != NULL)
+ kfree(child_obj_desc_array);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(dprc_scan_objects);
+
+/**
+ * dprc_scan_container - Scans a physical DPRC and synchronizes Linux bus state
+ *
+ * @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ *
+ * Scans the physical DPRC and synchronizes the state of the Linux
+ * bus driver with the actual state of the MC by adding and removing
+ * devices as appropriate.
+ */
+int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
+{
+ int error = -EINVAL;
+
+ error = dprc_scan_objects(mc_bus_dev);
+ if (error < 0)
+ goto error;
+
+ return 0;
+error:
+ return error;
+}
+EXPORT_SYMBOL_GPL(dprc_scan_container);
+
+/**
+ * dprc_probe - callback invoked when a DPRC is being bound to this driver
+ *
+ * @mc_dev: Pointer to fsl-mc device representing a DPRC
+ *
+ * It opens the physical DPRC in the MC.
+ * It scans the DPRC to discover the MC objects contained in it.
+ */
+static int dprc_probe(struct fsl_mc_device *mc_dev)
+{
+ int error = -EINVAL;
+ bool dprc_opened = false;
+
+ if (WARN_ON(strcmp(mc_dev->obj_desc.type, "dprc") != 0))
+ goto error;
+
+ error = dprc_open(mc_dev->mc_io, mc_dev->obj_desc.id,
+ &mc_dev->mc_handle);
+ if (error < 0) {
+ dev_err(&mc_dev->dev, "dprc_open() failed: %d\n", error);
+ goto error;
+ }
+
+ dprc_opened = true;
+ error = dprc_scan_container(mc_dev);
+ if (error < 0)
+ goto error;
+
+ dev_info(&mc_dev->dev, "DPRC device bound to driver");
+ return 0;
+error:
+ if (dprc_opened)
+ (void)dprc_close(mc_dev->mc_io, mc_dev->mc_handle);
+
+ return error;
+}
+
+/**
+ * dprc_remove - callback invoked when a DPRC is being unbound from this driver
+ *
+ * @mc_dev: Pointer to fsl-mc device representing the DPRC
+ *
+ * It removes the DPRC's child objects from Linux (not from the MC) and
+ * closes the DPRC device in the MC.
+ */
+static int dprc_remove(struct fsl_mc_device *mc_dev)
+{
+ int error = -EINVAL;
+
+ if (WARN_ON(strcmp(mc_dev->obj_desc.type, "dprc") != 0))
+ goto error;
+ if (WARN_ON(mc_dev->mc_io == NULL))
+ goto error;
+
+ device_for_each_child(&mc_dev->dev, NULL, __fsl_mc_device_remove);
+ error = dprc_close(mc_dev->mc_io, mc_dev->mc_handle);
+ if (error < 0)
+ dev_err(&mc_dev->dev, "dprc_close() failed: %d\n", error);
+
+ dev_info(&mc_dev->dev, "DPRC device unbound from driver");
+ return 0;
+error:
+ return error;
+}
+
+static const struct fsl_mc_device_match_id match_id_table[] = {
+ {
+ .vendor = FSL_MC_VENDOR_FREESCALE,
+ .obj_type = "dprc",
+ .ver_major = DPRC_VER_MAJOR,
+ .ver_minor = DPRC_VER_MINOR},
+ {.vendor = 0x0},
+};
+
+static struct fsl_mc_driver dprc_driver = {
+ .driver = {
+ .name = FSL_MC_DPRC_DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ },
+ .match_id_table = match_id_table,
+ .probe = dprc_probe,
+ .remove = dprc_remove,
+};
+
+module_fsl_mc_driver(dprc_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor Inc.");
+MODULE_DESCRIPTION("Freescale's DPRC container driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/fsl_mc_private.h b/include/linux/fsl_mc_private.h
index 3ff3f2b..ece79f3 100644
--- a/include/linux/fsl_mc_private.h
+++ b/include/linux/fsl_mc_private.h
@@ -15,6 +15,8 @@
#include <linux/mutex.h>
#include <linux/stringify.h>

+#define FSL_MC_DPRC_DRIVER_NAME "fsl_mc_dprc"
+
#define FSL_MC_DEVICE_MATCH(_mc_dev, _obj_desc) \
(strcmp((_mc_dev)->obj_desc.type, (_obj_desc)->type) == 0 && \
(_mc_dev)->obj_desc.id == (_obj_desc)->id)
@@ -30,4 +32,8 @@ int __must_check fsl_mc_device_add(struct dprc_obj_desc *obj_desc,

void fsl_mc_device_remove(struct fsl_mc_device *mc_dev);

+int __must_check dprc_scan_container(struct fsl_mc_device *mc_bus_dev);
+
+int __must_check dprc_scan_objects(struct fsl_mc_device *mc_bus_dev);
+
#endif /* _FSL_MC_PRIVATE_H_ */
--
1.7.9.7