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path: root/drivers/hwtracing/intel_th/core.c
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Diffstat (limited to 'drivers/hwtracing/intel_th/core.c')
-rw-r--r--drivers/hwtracing/intel_th/core.c1086
1 files changed, 1086 insertions, 0 deletions
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
new file mode 100644
index 000000000..9cb8c7d13
--- /dev/null
+++ b/drivers/hwtracing/intel_th/core.c
@@ -0,0 +1,1086 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel(R) Trace Hub driver core
+ *
+ * Copyright (C) 2014-2015 Intel Corporation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/kdev_t.h>
+#include <linux/debugfs.h>
+#include <linux/idr.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
+
+#include "intel_th.h"
+#include "debug.h"
+
+static bool host_mode __read_mostly;
+module_param(host_mode, bool, 0444);
+
+static DEFINE_IDA(intel_th_ida);
+
+static int intel_th_match(struct device *dev, struct device_driver *driver)
+{
+ struct intel_th_driver *thdrv = to_intel_th_driver(driver);
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+
+ if (thdev->type == INTEL_TH_SWITCH &&
+ (!thdrv->enable || !thdrv->disable))
+ return 0;
+
+ return !strcmp(thdev->name, driver->name);
+}
+
+static int intel_th_child_remove(struct device *dev, void *data)
+{
+ device_release_driver(dev);
+
+ return 0;
+}
+
+static int intel_th_probe(struct device *dev)
+{
+ struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+ struct intel_th_driver *hubdrv;
+ struct intel_th_device *hub = NULL;
+ int ret;
+
+ if (thdev->type == INTEL_TH_SWITCH)
+ hub = thdev;
+ else if (dev->parent)
+ hub = to_intel_th_device(dev->parent);
+
+ if (!hub || !hub->dev.driver)
+ return -EPROBE_DEFER;
+
+ hubdrv = to_intel_th_driver(hub->dev.driver);
+
+ pm_runtime_set_active(dev);
+ pm_runtime_no_callbacks(dev);
+ pm_runtime_enable(dev);
+
+ ret = thdrv->probe(to_intel_th_device(dev));
+ if (ret)
+ goto out_pm;
+
+ if (thdrv->attr_group) {
+ ret = sysfs_create_group(&thdev->dev.kobj, thdrv->attr_group);
+ if (ret)
+ goto out;
+ }
+
+ if (thdev->type == INTEL_TH_OUTPUT &&
+ !intel_th_output_assigned(thdev))
+ /* does not talk to hardware */
+ ret = hubdrv->assign(hub, thdev);
+
+out:
+ if (ret)
+ thdrv->remove(thdev);
+
+out_pm:
+ if (ret)
+ pm_runtime_disable(dev);
+
+ return ret;
+}
+
+static void intel_th_device_remove(struct intel_th_device *thdev);
+
+static int intel_th_remove(struct device *dev)
+{
+ struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+ struct intel_th_device *hub = to_intel_th_hub(thdev);
+ int err;
+
+ if (thdev->type == INTEL_TH_SWITCH) {
+ struct intel_th *th = to_intel_th(hub);
+ int i, lowest;
+
+ /* disconnect outputs */
+ err = device_for_each_child(dev, thdev, intel_th_child_remove);
+ if (err)
+ return err;
+
+ /*
+ * Remove outputs, that is, hub's children: they are created
+ * at hub's probe time by having the hub call
+ * intel_th_output_enable() for each of them.
+ */
+ for (i = 0, lowest = -1; i < th->num_thdevs; i++) {
+ /*
+ * Move the non-output devices from higher up the
+ * th->thdev[] array to lower positions to maintain
+ * a contiguous array.
+ */
+ if (th->thdev[i]->type != INTEL_TH_OUTPUT) {
+ if (lowest >= 0) {
+ th->thdev[lowest] = th->thdev[i];
+ th->thdev[i] = NULL;
+ ++lowest;
+ }
+
+ continue;
+ }
+
+ if (lowest == -1)
+ lowest = i;
+
+ intel_th_device_remove(th->thdev[i]);
+ th->thdev[i] = NULL;
+ }
+
+ if (lowest >= 0)
+ th->num_thdevs = lowest;
+ }
+
+ if (thdrv->attr_group)
+ sysfs_remove_group(&thdev->dev.kobj, thdrv->attr_group);
+
+ pm_runtime_get_sync(dev);
+
+ thdrv->remove(thdev);
+
+ if (intel_th_output_assigned(thdev)) {
+ struct intel_th_driver *hubdrv =
+ to_intel_th_driver(dev->parent->driver);
+
+ if (hub->dev.driver)
+ /* does not talk to hardware */
+ hubdrv->unassign(hub, thdev);
+ }
+
+ pm_runtime_disable(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ return 0;
+}
+
+static struct bus_type intel_th_bus = {
+ .name = "intel_th",
+ .match = intel_th_match,
+ .probe = intel_th_probe,
+ .remove = intel_th_remove,
+};
+
+static void intel_th_device_free(struct intel_th_device *thdev);
+
+static void intel_th_device_release(struct device *dev)
+{
+ intel_th_device_free(to_intel_th_device(dev));
+}
+
+static struct device_type intel_th_source_device_type = {
+ .name = "intel_th_source_device",
+ .release = intel_th_device_release,
+};
+
+static char *intel_th_output_devnode(struct device *dev, umode_t *mode,
+ kuid_t *uid, kgid_t *gid)
+{
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+ struct intel_th *th = to_intel_th(thdev);
+ char *node;
+
+ if (thdev->id >= 0)
+ node = kasprintf(GFP_KERNEL, "intel_th%d/%s%d", th->id,
+ thdev->name, thdev->id);
+ else
+ node = kasprintf(GFP_KERNEL, "intel_th%d/%s", th->id,
+ thdev->name);
+
+ return node;
+}
+
+static ssize_t port_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+
+ if (thdev->output.port >= 0)
+ return scnprintf(buf, PAGE_SIZE, "%u\n", thdev->output.port);
+
+ return scnprintf(buf, PAGE_SIZE, "unassigned\n");
+}
+
+static DEVICE_ATTR_RO(port);
+
+static void intel_th_trace_prepare(struct intel_th_device *thdev)
+{
+ struct intel_th_device *hub = to_intel_th_hub(thdev);
+ struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+
+ if (hub->type != INTEL_TH_SWITCH)
+ return;
+
+ if (thdev->type != INTEL_TH_OUTPUT)
+ return;
+
+ pm_runtime_get_sync(&thdev->dev);
+ hubdrv->prepare(hub, &thdev->output);
+ pm_runtime_put(&thdev->dev);
+}
+
+static int intel_th_output_activate(struct intel_th_device *thdev)
+{
+ struct intel_th_driver *thdrv =
+ to_intel_th_driver_or_null(thdev->dev.driver);
+ struct intel_th *th = to_intel_th(thdev);
+ int ret = 0;
+
+ if (!thdrv)
+ return -ENODEV;
+
+ if (!try_module_get(thdrv->driver.owner))
+ return -ENODEV;
+
+ pm_runtime_get_sync(&thdev->dev);
+
+ if (th->activate)
+ ret = th->activate(th);
+ if (ret)
+ goto fail_put;
+
+ intel_th_trace_prepare(thdev);
+ if (thdrv->activate)
+ ret = thdrv->activate(thdev);
+ else
+ intel_th_trace_enable(thdev);
+
+ if (ret)
+ goto fail_deactivate;
+
+ return 0;
+
+fail_deactivate:
+ if (th->deactivate)
+ th->deactivate(th);
+
+fail_put:
+ pm_runtime_put(&thdev->dev);
+ module_put(thdrv->driver.owner);
+
+ return ret;
+}
+
+static void intel_th_output_deactivate(struct intel_th_device *thdev)
+{
+ struct intel_th_driver *thdrv =
+ to_intel_th_driver_or_null(thdev->dev.driver);
+ struct intel_th *th = to_intel_th(thdev);
+
+ if (!thdrv)
+ return;
+
+ if (thdrv->deactivate)
+ thdrv->deactivate(thdev);
+ else
+ intel_th_trace_disable(thdev);
+
+ if (th->deactivate)
+ th->deactivate(th);
+
+ pm_runtime_put(&thdev->dev);
+ module_put(thdrv->driver.owner);
+}
+
+static ssize_t active_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", thdev->output.active);
+}
+
+static ssize_t active_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct intel_th_device *thdev = to_intel_th_device(dev);
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ if (!!val != thdev->output.active) {
+ if (val)
+ ret = intel_th_output_activate(thdev);
+ else
+ intel_th_output_deactivate(thdev);
+ }
+
+ return ret ? ret : size;
+}
+
+static DEVICE_ATTR_RW(active);
+
+static struct attribute *intel_th_output_attrs[] = {
+ &dev_attr_port.attr,
+ &dev_attr_active.attr,
+ NULL,
+};
+
+ATTRIBUTE_GROUPS(intel_th_output);
+
+static struct device_type intel_th_output_device_type = {
+ .name = "intel_th_output_device",
+ .groups = intel_th_output_groups,
+ .release = intel_th_device_release,
+ .devnode = intel_th_output_devnode,
+};
+
+static struct device_type intel_th_switch_device_type = {
+ .name = "intel_th_switch_device",
+ .release = intel_th_device_release,
+};
+
+static struct device_type *intel_th_device_type[] = {
+ [INTEL_TH_SOURCE] = &intel_th_source_device_type,
+ [INTEL_TH_OUTPUT] = &intel_th_output_device_type,
+ [INTEL_TH_SWITCH] = &intel_th_switch_device_type,
+};
+
+int intel_th_driver_register(struct intel_th_driver *thdrv)
+{
+ if (!thdrv->probe || !thdrv->remove)
+ return -EINVAL;
+
+ thdrv->driver.bus = &intel_th_bus;
+
+ return driver_register(&thdrv->driver);
+}
+EXPORT_SYMBOL_GPL(intel_th_driver_register);
+
+void intel_th_driver_unregister(struct intel_th_driver *thdrv)
+{
+ driver_unregister(&thdrv->driver);
+}
+EXPORT_SYMBOL_GPL(intel_th_driver_unregister);
+
+static struct intel_th_device *
+intel_th_device_alloc(struct intel_th *th, unsigned int type, const char *name,
+ int id)
+{
+ struct device *parent;
+ struct intel_th_device *thdev;
+
+ if (type == INTEL_TH_OUTPUT)
+ parent = &th->hub->dev;
+ else
+ parent = th->dev;
+
+ thdev = kzalloc(sizeof(*thdev) + strlen(name) + 1, GFP_KERNEL);
+ if (!thdev)
+ return NULL;
+
+ thdev->id = id;
+ thdev->type = type;
+
+ strcpy(thdev->name, name);
+ device_initialize(&thdev->dev);
+ thdev->dev.bus = &intel_th_bus;
+ thdev->dev.type = intel_th_device_type[type];
+ thdev->dev.parent = parent;
+ thdev->dev.dma_mask = parent->dma_mask;
+ thdev->dev.dma_parms = parent->dma_parms;
+ dma_set_coherent_mask(&thdev->dev, parent->coherent_dma_mask);
+ if (id >= 0)
+ dev_set_name(&thdev->dev, "%d-%s%d", th->id, name, id);
+ else
+ dev_set_name(&thdev->dev, "%d-%s", th->id, name);
+
+ return thdev;
+}
+
+static int intel_th_device_add_resources(struct intel_th_device *thdev,
+ struct resource *res, int nres)
+{
+ struct resource *r;
+
+ r = kmemdup(res, sizeof(*res) * nres, GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
+
+ thdev->resource = r;
+ thdev->num_resources = nres;
+
+ return 0;
+}
+
+static void intel_th_device_remove(struct intel_th_device *thdev)
+{
+ device_del(&thdev->dev);
+ put_device(&thdev->dev);
+}
+
+static void intel_th_device_free(struct intel_th_device *thdev)
+{
+ kfree(thdev->resource);
+ kfree(thdev);
+}
+
+/*
+ * Intel(R) Trace Hub subdevices
+ */
+static const struct intel_th_subdevice {
+ const char *name;
+ struct resource res[3];
+ unsigned nres;
+ unsigned type;
+ unsigned otype;
+ bool mknode;
+ unsigned scrpd;
+ int id;
+} intel_th_subdevices[] = {
+ {
+ .nres = 1,
+ .res = {
+ {
+ /* Handle TSCU and CTS from GTH driver */
+ .start = REG_GTH_OFFSET,
+ .end = REG_CTS_OFFSET + REG_CTS_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .name = "gth",
+ .type = INTEL_TH_SWITCH,
+ .id = -1,
+ },
+ {
+ .nres = 2,
+ .res = {
+ {
+ .start = REG_MSU_OFFSET,
+ .end = REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ {
+ .start = BUF_MSU_OFFSET,
+ .end = BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .name = "msc",
+ .id = 0,
+ .type = INTEL_TH_OUTPUT,
+ .mknode = true,
+ .otype = GTH_MSU,
+ .scrpd = SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC0_IS_ENABLED,
+ },
+ {
+ .nres = 2,
+ .res = {
+ {
+ .start = REG_MSU_OFFSET,
+ .end = REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ {
+ .start = BUF_MSU_OFFSET,
+ .end = BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .name = "msc",
+ .id = 1,
+ .type = INTEL_TH_OUTPUT,
+ .mknode = true,
+ .otype = GTH_MSU,
+ .scrpd = SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC1_IS_ENABLED,
+ },
+ {
+ .nres = 2,
+ .res = {
+ {
+ .start = REG_STH_OFFSET,
+ .end = REG_STH_OFFSET + REG_STH_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ {
+ .start = TH_MMIO_SW,
+ .end = 0,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .id = -1,
+ .name = "sth",
+ .type = INTEL_TH_SOURCE,
+ },
+ {
+ .nres = 2,
+ .res = {
+ {
+ .start = REG_STH_OFFSET,
+ .end = REG_STH_OFFSET + REG_STH_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ {
+ .start = TH_MMIO_RTIT,
+ .end = 0,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .id = -1,
+ .name = "rtit",
+ .type = INTEL_TH_SOURCE,
+ },
+ {
+ .nres = 1,
+ .res = {
+ {
+ .start = REG_PTI_OFFSET,
+ .end = REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .id = -1,
+ .name = "pti",
+ .type = INTEL_TH_OUTPUT,
+ .otype = GTH_PTI,
+ .scrpd = SCRPD_PTI_IS_PRIM_DEST,
+ },
+ {
+ .nres = 1,
+ .res = {
+ {
+ .start = REG_PTI_OFFSET,
+ .end = REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .id = -1,
+ .name = "lpp",
+ .type = INTEL_TH_OUTPUT,
+ .otype = GTH_LPP,
+ .scrpd = SCRPD_PTI_IS_PRIM_DEST,
+ },
+ {
+ .nres = 1,
+ .res = {
+ {
+ .start = REG_DCIH_OFFSET,
+ .end = REG_DCIH_OFFSET + REG_DCIH_LENGTH - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ },
+ .id = -1,
+ .name = "dcih",
+ .type = INTEL_TH_OUTPUT,
+ },
+};
+
+#ifdef CONFIG_MODULES
+static void __intel_th_request_hub_module(struct work_struct *work)
+{
+ struct intel_th *th = container_of(work, struct intel_th,
+ request_module_work);
+
+ request_module("intel_th_%s", th->hub->name);
+}
+
+static int intel_th_request_hub_module(struct intel_th *th)
+{
+ INIT_WORK(&th->request_module_work, __intel_th_request_hub_module);
+ schedule_work(&th->request_module_work);
+
+ return 0;
+}
+
+static void intel_th_request_hub_module_flush(struct intel_th *th)
+{
+ flush_work(&th->request_module_work);
+}
+#else
+static inline int intel_th_request_hub_module(struct intel_th *th)
+{
+ return -EINVAL;
+}
+
+static inline void intel_th_request_hub_module_flush(struct intel_th *th)
+{
+}
+#endif /* CONFIG_MODULES */
+
+static struct intel_th_device *
+intel_th_subdevice_alloc(struct intel_th *th,
+ const struct intel_th_subdevice *subdev)
+{
+ struct intel_th_device *thdev;
+ struct resource res[3];
+ unsigned int req = 0;
+ int r, err;
+
+ thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
+ subdev->id);
+ if (!thdev)
+ return ERR_PTR(-ENOMEM);
+
+ thdev->drvdata = th->drvdata;
+
+ memcpy(res, subdev->res,
+ sizeof(struct resource) * subdev->nres);
+
+ for (r = 0; r < subdev->nres; r++) {
+ struct resource *devres = th->resource;
+ int bar = TH_MMIO_CONFIG;
+
+ /*
+ * Take .end == 0 to mean 'take the whole bar',
+ * .start then tells us which bar it is. Default to
+ * TH_MMIO_CONFIG.
+ */
+ if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
+ bar = res[r].start;
+ err = -ENODEV;
+ if (bar >= th->num_resources)
+ goto fail_put_device;
+ res[r].start = 0;
+ res[r].end = resource_size(&devres[bar]) - 1;
+ }
+
+ if (res[r].flags & IORESOURCE_MEM) {
+ res[r].start += devres[bar].start;
+ res[r].end += devres[bar].start;
+
+ dev_dbg(th->dev, "%s:%d @ %pR\n",
+ subdev->name, r, &res[r]);
+ } else if (res[r].flags & IORESOURCE_IRQ) {
+ /*
+ * Only pass on the IRQ if we have useful interrupts:
+ * the ones that can be configured via MINTCTL.
+ */
+ if (INTEL_TH_CAP(th, has_mintctl) && th->irq != -1)
+ res[r].start = th->irq;
+ }
+ }
+
+ err = intel_th_device_add_resources(thdev, res, subdev->nres);
+ if (err)
+ goto fail_put_device;
+
+ if (subdev->type == INTEL_TH_OUTPUT) {
+ if (subdev->mknode)
+ thdev->dev.devt = MKDEV(th->major, th->num_thdevs);
+ thdev->output.type = subdev->otype;
+ thdev->output.port = -1;
+ thdev->output.scratchpad = subdev->scrpd;
+ } else if (subdev->type == INTEL_TH_SWITCH) {
+ thdev->host_mode =
+ INTEL_TH_CAP(th, host_mode_only) ? true : host_mode;
+ th->hub = thdev;
+ }
+
+ err = device_add(&thdev->dev);
+ if (err)
+ goto fail_free_res;
+
+ /* need switch driver to be loaded to enumerate the rest */
+ if (subdev->type == INTEL_TH_SWITCH && !req) {
+ err = intel_th_request_hub_module(th);
+ if (!err)
+ req++;
+ }
+
+ return thdev;
+
+fail_free_res:
+ kfree(thdev->resource);
+
+fail_put_device:
+ put_device(&thdev->dev);
+
+ return ERR_PTR(err);
+}
+
+/**
+ * intel_th_output_enable() - find and enable a device for a given output type
+ * @th: Intel TH instance
+ * @otype: output type
+ *
+ * Go through the unallocated output devices, find the first one whos type
+ * matches @otype and instantiate it. These devices are removed when the hub
+ * device is removed, see intel_th_remove().
+ */
+int intel_th_output_enable(struct intel_th *th, unsigned int otype)
+{
+ struct intel_th_device *thdev;
+ int src = 0, dst = 0;
+
+ for (src = 0, dst = 0; dst <= th->num_thdevs; src++, dst++) {
+ for (; src < ARRAY_SIZE(intel_th_subdevices); src++) {
+ if (intel_th_subdevices[src].type != INTEL_TH_OUTPUT)
+ continue;
+
+ if (intel_th_subdevices[src].otype != otype)
+ continue;
+
+ break;
+ }
+
+ /* no unallocated matching subdevices */
+ if (src == ARRAY_SIZE(intel_th_subdevices))
+ return -ENODEV;
+
+ for (; dst < th->num_thdevs; dst++) {
+ if (th->thdev[dst]->type != INTEL_TH_OUTPUT)
+ continue;
+
+ if (th->thdev[dst]->output.type != otype)
+ continue;
+
+ break;
+ }
+
+ /*
+ * intel_th_subdevices[src] matches our requirements and is
+ * not matched in th::thdev[]
+ */
+ if (dst == th->num_thdevs)
+ goto found;
+ }
+
+ return -ENODEV;
+
+found:
+ thdev = intel_th_subdevice_alloc(th, &intel_th_subdevices[src]);
+ if (IS_ERR(thdev))
+ return PTR_ERR(thdev);
+
+ th->thdev[th->num_thdevs++] = thdev;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_th_output_enable);
+
+static int intel_th_populate(struct intel_th *th)
+{
+ int src;
+
+ /* create devices for each intel_th_subdevice */
+ for (src = 0; src < ARRAY_SIZE(intel_th_subdevices); src++) {
+ const struct intel_th_subdevice *subdev =
+ &intel_th_subdevices[src];
+ struct intel_th_device *thdev;
+
+ /* only allow SOURCE and SWITCH devices in host mode */
+ if ((INTEL_TH_CAP(th, host_mode_only) || host_mode) &&
+ subdev->type == INTEL_TH_OUTPUT)
+ continue;
+
+ /*
+ * don't enable port OUTPUTs in this path; SWITCH enables them
+ * via intel_th_output_enable()
+ */
+ if (subdev->type == INTEL_TH_OUTPUT &&
+ subdev->otype != GTH_NONE)
+ continue;
+
+ thdev = intel_th_subdevice_alloc(th, subdev);
+ /* note: caller should free subdevices from th::thdev[] */
+ if (IS_ERR(thdev)) {
+ /* ENODEV for individual subdevices is allowed */
+ if (PTR_ERR(thdev) == -ENODEV)
+ continue;
+
+ return PTR_ERR(thdev);
+ }
+
+ th->thdev[th->num_thdevs++] = thdev;
+ }
+
+ return 0;
+}
+
+static int intel_th_output_open(struct inode *inode, struct file *file)
+{
+ const struct file_operations *fops;
+ struct intel_th_driver *thdrv;
+ struct device *dev;
+ int err;
+
+ dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev);
+ if (!dev || !dev->driver)
+ return -ENODEV;
+
+ thdrv = to_intel_th_driver(dev->driver);
+ fops = fops_get(thdrv->fops);
+ if (!fops)
+ return -ENODEV;
+
+ replace_fops(file, fops);
+
+ file->private_data = to_intel_th_device(dev);
+
+ if (file->f_op->open) {
+ err = file->f_op->open(inode, file);
+ return err;
+ }
+
+ return 0;
+}
+
+static const struct file_operations intel_th_output_fops = {
+ .open = intel_th_output_open,
+ .llseek = noop_llseek,
+};
+
+static irqreturn_t intel_th_irq(int irq, void *data)
+{
+ struct intel_th *th = data;
+ irqreturn_t ret = IRQ_NONE;
+ struct intel_th_driver *d;
+ int i;
+
+ for (i = 0; i < th->num_thdevs; i++) {
+ if (th->thdev[i]->type != INTEL_TH_OUTPUT)
+ continue;
+
+ d = to_intel_th_driver(th->thdev[i]->dev.driver);
+ if (d && d->irq)
+ ret |= d->irq(th->thdev[i]);
+ }
+
+ return ret;
+}
+
+/**
+ * intel_th_alloc() - allocate a new Intel TH device and its subdevices
+ * @dev: parent device
+ * @devres: resources indexed by th_mmio_idx
+ * @irq: irq number
+ */
+struct intel_th *
+intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
+ struct resource *devres, unsigned int ndevres)
+{
+ int err, r, nr_mmios = 0;
+ struct intel_th *th;
+
+ th = kzalloc(sizeof(*th), GFP_KERNEL);
+ if (!th)
+ return ERR_PTR(-ENOMEM);
+
+ th->id = ida_simple_get(&intel_th_ida, 0, 0, GFP_KERNEL);
+ if (th->id < 0) {
+ err = th->id;
+ goto err_alloc;
+ }
+
+ th->major = __register_chrdev(0, 0, TH_POSSIBLE_OUTPUTS,
+ "intel_th/output", &intel_th_output_fops);
+ if (th->major < 0) {
+ err = th->major;
+ goto err_ida;
+ }
+ th->irq = -1;
+ th->dev = dev;
+ th->drvdata = drvdata;
+
+ for (r = 0; r < ndevres; r++)
+ switch (devres[r].flags & IORESOURCE_TYPE_BITS) {
+ case IORESOURCE_MEM:
+ th->resource[nr_mmios++] = devres[r];
+ break;
+ case IORESOURCE_IRQ:
+ err = devm_request_irq(dev, devres[r].start,
+ intel_th_irq, IRQF_SHARED,
+ dev_name(dev), th);
+ if (err)
+ goto err_chrdev;
+
+ if (th->irq == -1)
+ th->irq = devres[r].start;
+ th->num_irqs++;
+ break;
+ default:
+ dev_warn(dev, "Unknown resource type %lx\n",
+ devres[r].flags);
+ break;
+ }
+
+ th->num_resources = nr_mmios;
+
+ dev_set_drvdata(dev, th);
+
+ pm_runtime_no_callbacks(dev);
+ pm_runtime_put(dev);
+ pm_runtime_allow(dev);
+
+ err = intel_th_populate(th);
+ if (err) {
+ /* free the subdevices and undo everything */
+ intel_th_free(th);
+ return ERR_PTR(err);
+ }
+
+ return th;
+
+err_chrdev:
+ __unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
+ "intel_th/output");
+
+err_ida:
+ ida_simple_remove(&intel_th_ida, th->id);
+
+err_alloc:
+ kfree(th);
+
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(intel_th_alloc);
+
+void intel_th_free(struct intel_th *th)
+{
+ int i;
+
+ intel_th_request_hub_module_flush(th);
+
+ intel_th_device_remove(th->hub);
+ for (i = 0; i < th->num_thdevs; i++) {
+ if (th->thdev[i] != th->hub)
+ intel_th_device_remove(th->thdev[i]);
+ th->thdev[i] = NULL;
+ }
+
+ th->num_thdevs = 0;
+
+ for (i = 0; i < th->num_irqs; i++)
+ devm_free_irq(th->dev, th->irq + i, th);
+
+ pm_runtime_get_sync(th->dev);
+ pm_runtime_forbid(th->dev);
+
+ __unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
+ "intel_th/output");
+
+ ida_simple_remove(&intel_th_ida, th->id);
+
+ kfree(th);
+}
+EXPORT_SYMBOL_GPL(intel_th_free);
+
+/**
+ * intel_th_trace_enable() - enable tracing for an output device
+ * @thdev: output device that requests tracing be enabled
+ */
+int intel_th_trace_enable(struct intel_th_device *thdev)
+{
+ struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
+ struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+
+ if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
+ return -EINVAL;
+
+ pm_runtime_get_sync(&thdev->dev);
+ hubdrv->enable(hub, &thdev->output);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_th_trace_enable);
+
+/**
+ * intel_th_trace_switch() - execute a switch sequence
+ * @thdev: output device that requests tracing switch
+ */
+int intel_th_trace_switch(struct intel_th_device *thdev)
+{
+ struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
+ struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+
+ if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
+ return -EINVAL;
+
+ hubdrv->trig_switch(hub, &thdev->output);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_th_trace_switch);
+
+/**
+ * intel_th_trace_disable() - disable tracing for an output device
+ * @thdev: output device that requests tracing be disabled
+ */
+int intel_th_trace_disable(struct intel_th_device *thdev)
+{
+ struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
+ struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+
+ WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH);
+ if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
+ return -EINVAL;
+
+ hubdrv->disable(hub, &thdev->output);
+ pm_runtime_put(&thdev->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_th_trace_disable);
+
+int intel_th_set_output(struct intel_th_device *thdev,
+ unsigned int master)
+{
+ struct intel_th_device *hub = to_intel_th_hub(thdev);
+ struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
+ int ret;
+
+ /* In host mode, this is up to the external debugger, do nothing. */
+ if (hub->host_mode)
+ return 0;
+
+ /*
+ * hub is instantiated together with the source device that
+ * calls here, so guaranteed to be present.
+ */
+ hubdrv = to_intel_th_driver(hub->dev.driver);
+ if (!hubdrv || !try_module_get(hubdrv->driver.owner))
+ return -EINVAL;
+
+ if (!hubdrv->set_output) {
+ ret = -ENOTSUPP;
+ goto out;
+ }
+
+ ret = hubdrv->set_output(hub, master);
+
+out:
+ module_put(hubdrv->driver.owner);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(intel_th_set_output);
+
+static int __init intel_th_init(void)
+{
+ intel_th_debug_init();
+
+ return bus_register(&intel_th_bus);
+}
+subsys_initcall(intel_th_init);
+
+static void __exit intel_th_exit(void)
+{
+ intel_th_debug_done();
+
+ bus_unregister(&intel_th_bus);
+}
+module_exit(intel_th_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel(R) Trace Hub controller driver");
+MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");