From c49a75910c5ea9bbeb60a86350f232f6fcb13cc2 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Mon, 19 Sep 2016 17:07:47 +0300 Subject: [PATCH] intel_th: Support Host Debugger mode of operation This patch adds a 'host_mode' module option to enable host-driven operational mode in the driver. In this mode, the driver does not perform trace configuration or enable trace capture, but still provides all the means necessary for software trace sources to write their data to the Trace Hub. This means that the debug host takes care of all the configuration and enabling and we do not interfere. Signed-off-by: Alexander Shishkin --- drivers/hwtracing/intel_th/core.c | 26 ++++++++++++++++++-------- drivers/hwtracing/intel_th/intel_th.h | 4 ++++ 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index 79e19627b99f..cdd9b3b26195 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -29,6 +29,9 @@ #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) @@ -527,14 +530,19 @@ static int intel_th_populate(struct intel_th *th, struct resource *devres, { struct resource res[3]; unsigned int req = 0; - int i, err; + int src, dst, err; /* create devices for each intel_th_subdevice */ - for (i = 0; i < ARRAY_SIZE(intel_th_subdevices); i++) { - struct intel_th_subdevice *subdev = &intel_th_subdevices[i]; + for (src = 0, dst = 0; src < ARRAY_SIZE(intel_th_subdevices); src++) { + const struct intel_th_subdevice *subdev = + &intel_th_subdevices[src]; struct intel_th_device *thdev; int r; + /* only allow SOURCE and SWITCH devices in host mode */ + if (host_mode && subdev->type == INTEL_TH_OUTPUT) + continue; + thdev = intel_th_device_alloc(th, subdev->type, subdev->name, subdev->id); if (!thdev) { @@ -577,10 +585,12 @@ static int intel_th_populate(struct intel_th *th, struct resource *devres, } if (subdev->type == INTEL_TH_OUTPUT) { - thdev->dev.devt = MKDEV(th->major, i); + thdev->dev.devt = MKDEV(th->major, dst); thdev->output.type = subdev->otype; thdev->output.port = -1; thdev->output.scratchpad = subdev->scrpd; + } else if (subdev->type == INTEL_TH_SWITCH) { + thdev->host_mode = host_mode; } err = device_add(&thdev->dev); @@ -597,14 +607,14 @@ static int intel_th_populate(struct intel_th *th, struct resource *devres, req++; } - th->thdev[i] = thdev; + th->thdev[dst++] = thdev; } return 0; kill_subdevs: - for (i-- ; i >= 0; i--) - intel_th_device_remove(th->thdev[i]); + for (; dst >= 0; dst--) + intel_th_device_remove(th->thdev[dst]); return err; } @@ -717,7 +727,7 @@ void intel_th_free(struct intel_th *th) intel_th_request_hub_module_flush(th); for (i = 0; i < TH_SUBDEVICE_MAX; i++) - if (th->thdev[i] != th->hub) + if (th->thdev[i] && th->thdev[i] != th->hub) intel_th_device_remove(th->thdev[i]); intel_th_device_remove(th->hub); diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h index 4c195786bf1f..3096e7054f6d 100644 --- a/drivers/hwtracing/intel_th/intel_th.h +++ b/drivers/hwtracing/intel_th/intel_th.h @@ -54,6 +54,7 @@ struct intel_th_output { * @num_resources: number of resources in @resource array * @type: INTEL_TH_{SOURCE,OUTPUT,SWITCH} * @id: device instance or -1 + * @host_mode: Intel TH is controlled by an external debug host * @output: output descriptor for INTEL_TH_OUTPUT devices * @name: device name to match the driver */ @@ -64,6 +65,9 @@ struct intel_th_device { unsigned int type; int id; + /* INTEL_TH_SWITCH specific */ + bool host_mode; + /* INTEL_TH_OUTPUT specific */ struct intel_th_output output; -- 2.20.1