Re: [PATCH V3 6/6] coresight-stm: adding driver for CoreSight STM component

From: Mathieu Poirier
Date: Fri Feb 12 2016 - 13:24:44 EST

On 12 February 2016 at 07:55, Michael Williams <Michael.Williams@xxxxxxx> wrote:
> Mathieu Poirier [mailto:mathieu.poirier@xxxxxxxxxx] wrote:
>> On 6 February 2016 at 04:04, Chunyan Zhang <zhang.chunyan@xxxxxxxxxx> wrote:
>>> From: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
>>>
>>> This driver adds support for the STM CoreSight IP block, allowing any
>>> system compoment (HW or SW) to log and aggregate messages via a
>>> single entity.
>>>
>>> The CoreSight STM exposes an application defined number of channels
>>> called stimulus port. Configuration is done using entries in sysfs
>>> and channels made available to userspace via configfs.
>>>
>>> Signed-off-by: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
>>> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
>>> ---
>>> .../ABI/testing/sysfs-bus-coresight-devices-stm | 53 ++
>>> Documentation/trace/coresight.txt | 37 +-
>>> drivers/hwtracing/coresight/Kconfig | 11 +
>>> drivers/hwtracing/coresight/Makefile | 1 +
>>> drivers/hwtracing/coresight/coresight-stm.c | 928 +++++++++++++++++++++
>>> include/linux/coresight-stm.h | 6 +
>>> include/uapi/linux/coresight-stm.h | 12 +
>>> 7 files changed, 1046 insertions(+), 2 deletions(-)
>>> create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
>>> create mode 100644 drivers/hwtracing/coresight/coresight-stm.c
>>> create mode 100644 include/linux/coresight-stm.h
>>> create mode 100644 include/uapi/linux/coresight-stm.h
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
>>> new file mode 100644
>>> index 0000000..a1d7022
>>> --- /dev/null
>>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
>>> @@ -0,0 +1,53 @@
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/enable_source
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Enable/disable tracing on this specific trace macrocell.
>>> + Enabling the trace macrocell implies it has been configured
>>> + properly and a sink has been identidifed for it. The path
>>> + of coresight components linking the source to the sink is
>>> + configured and managed automatically by the coresight framework.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/hwevent_enable
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Provides access to the HW event enable register, used in
>>> + conjunction with HW event bank select register.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/hwevent_select
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Gives access to the HW event block select register
>>> + (STMHEBSR) in order to configure up to 256 channels. Used in
>>> + conjunction with "hwevent_enable" register as described above.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/port_enable
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Provides access to the stimlus port enable register
>>> + (STMSPER). Used in conjunction with "port_select" described
>>> + below.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/port_select
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Used to determine which bank of stimulus port bit in
>>> + register STMSPER (see above) apply to.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/status
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (R) List various control and status registers. The specific
>>> + layout and content is driver specific.
>>> +
>>> +What: /sys/bus/coresight/devices/<memory_map>.stm/traceid
>>> +Date: February 2016
>>> +KernelVersion: 4.5
>>> +Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> +Description: (RW) Holds the trace ID that will appear in the trace stream
>>> + coming from this trace entity.
>>> diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt
>>> index 0a5c329..a33c88c 100644
>>> --- a/Documentation/trace/coresight.txt
>>> +++ b/Documentation/trace/coresight.txt
>>> @@ -190,8 +190,8 @@ expected to be accessed and controlled using those entries.
>>> Last but not least, "struct module *owner" is expected to be set to reflect
>>> the information carried in "THIS_MODULE".
>>>
>>> -How to use
>>> -----------
>>> +How to use the tracer modules
>>> +-----------------------------
>>>
>>> Before trace collection can start, a coresight sink needs to be identify.
>>> There is no limit on the amount of sinks (nor sources) that can be enabled at
>>> @@ -297,3 +297,36 @@ Info Tracing enabled
>>> Instruction 13570831 0x8026B584 E28DD00C false ADD
>> sp,sp,#0xc
>>> Instruction 0 0x8026B588 E8BD8000 true LDM sp!,{pc}
>>> Timestamp Timestamp: 17107041535
>>> +
>>> +How to use the STM module
>>> +-------------------------
>>> +
>>> +Using the System Trace Macrocell module is the same as the tracers - the only
>>> +difference is that clients are driving the trace capture rather
>>> +than the program flow through the code.
>>> +
>>> +As with any other CoreSight component, specifics about the STM tracer can be
>>> +found in sysfs with more information on each entry being found in [1]:
>>> +
>>> +root@genericarmv8:~# ls /sys/bus/coresight/devices/20100000.stm
>>> +enable_source hwevent_select port_enable subsystem uevent
>>> +hwevent_enable mgmt port_select traceid
>>> +root@genericarmv8:~#
>>> +
>>> +Like any other source a sink needs to be identified and the STM enabled before
>>> +being used:
>>> +
>>> +root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20010000.etf/enable_sink
>>> +root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20100000.stm/enable_source
>>> +
>>> +From there user space applications can request and use channels using the devfs
>>> +interface provided for that purpose by the generic STM API:
>>> +
>>> +root@genericarmv8:~# ls -l /dev/20100000.stm
>>> +crw------- 1 root root 10, 61 Jan 3 18:11 /dev/20100000.stm
>>> +root@genericarmv8:~#
>>> +
>>> +Details on how to use the generic STM API can be found here [2].
>>> +
>>> +[1]. Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
>>> +[2]. Documentation/trace/stm.txt
>>> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
>>> index c85935f..f4a8bfa 100644
>>> --- a/drivers/hwtracing/coresight/Kconfig
>>> +++ b/drivers/hwtracing/coresight/Kconfig
>>> @@ -77,4 +77,15 @@ config CORESIGHT_QCOM_REPLICATOR
>>> programmable ATB replicator sends the ATB trace stream from the
>>> ETB/ETF to the TPIUi and ETR.
>>>
>>> +config CORESIGHT_STM
>>> + bool "CoreSight System Trace Macrocell driver"
>>> + depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64
>>> + select CORESIGHT_LINKS_AND_SINKS
>>> + select STM
>>> + help
>>> + This driver provides support for hardware assisted software
>>> + instrumentation based tracing. This is primarily used for
>>> + logging useful software events or data coming from various entities
>>> + in the system, possibly running different OSs
>>> +
>>> endif
>>> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
>>> index 99f8e5f..1f6eaec 100644
>>> --- a/drivers/hwtracing/coresight/Makefile
>>> +++ b/drivers/hwtracing/coresight/Makefile
>>> @@ -11,3 +11,4 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
>>> obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o
>>> obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o
>>> obj-$(CONFIG_CORESIGHT_QCOM_REPLICATOR) += coresight-replicator-qcom.o
>>> +obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
>>> diff --git a/drivers/hwtracing/coresight/coresight-stm.c
>> b/drivers/hwtracing/coresight/coresight-stm.c
>>> new file mode 100644
>>> index 0000000..01b3521
>>> --- /dev/null
>>> +++ b/drivers/hwtracing/coresight/coresight-stm.c
>>> @@ -0,0 +1,928 @@
>>> +/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 and
>>> + * only version 2 as published by the Free Software Foundation.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * Initial implementation by Pratik Patel
>>> + * (C) 2014-2015 Pratik Patel <pratikp@xxxxxxxxxxxxxx>
>>> + *
>>> + * Serious refactoring, code cleanup and upgrading to the Coresight upstream
>>> + * framework by Mathieu Poirier
>>> + * (C) 2015-2016 Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>> + *
>>> + * Guaranteed timing and support for various packet type coming from the
>>> + * generic STM API by Chunyan Zhang
>>> + * (C) 2015-2016 Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
>>> + */
>>> +#include <linux/amba/bus.h>
>>> +#include <linux/bitmap.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/coresight.h>
>>> +#include <linux/coresight-stm.h>
>>> +#include <linux/err.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/stm.h>
>>> +
>>> +#include "coresight-priv.h"
>>> +
>>> +#define STMDMASTARTR 0xc04
>>> +#define STMDMASTOPR 0xc08
>>> +#define STMDMASTATR 0xc0c
>>> +#define STMDMACTLR 0xc10
>>> +#define STMDMAIDR 0xcfc
>>> +#define STMHEER 0xd00
>>> +#define STMHETER 0xd20
>>> +#define STMHEBSR 0xd60
>>> +#define STMHEMCR 0xd64
>>> +#define STMHEMASTR 0xdf4
>>> +#define STMHEFEAT1R 0xdf8
>>> +#define STMHEIDR 0xdfc
>>> +#define STMSPER 0xe00
>>> +#define STMSPTER 0xe20
>>> +#define STMPRIVMASKR 0xe40
>>> +#define STMSPSCR 0xe60
>>> +#define STMSPMSCR 0xe64
>>> +#define STMSPOVERRIDER 0xe68
>>> +#define STMSPMOVERRIDER 0xe6c
>>> +#define STMSPTRIGCSR 0xe70
>>> +#define STMTCSR 0xe80
>>> +#define STMTSSTIMR 0xe84
>>> +#define STMTSFREQR 0xe8c
>>> +#define STMSYNCR 0xe90
>>> +#define STMAUXCR 0xe94
>>> +#define STMSPFEAT1R 0xea0
>>> +#define STMSPFEAT2R 0xea4
>>> +#define STMSPFEAT3R 0xea8
>>> +#define STMITTRIGGER 0xee8
>>> +#define STMITATBDATA0 0xeec
>>> +#define STMITATBCTR2 0xef0
>>> +#define STMITATBID 0xef4
>>> +#define STMITATBCTR0 0xef8
>>> +
>>> +#define STM_32_CHANNEL 32
>>> +#define BYTES_PER_CHANNEL 256
>>> +#define STM_TRACE_BUF_SIZE 4096
>>> +#define STM_SW_MASTER_END 127
>>> +
>>> +/* Register bit definition */
>>> +#define STMTCSR_BUSY_BIT 23
>>> +/* Reserve the first 10 channels for kernel usage */
>>> +#define STM_CHANNEL_OFFSET 0
>>> +
>>> +enum stm_pkt_type {
>>> + STM_PKT_TYPE_DATA = 0x98,
>>> + STM_PKT_TYPE_FLAG = 0xE8,
>>> + STM_PKT_TYPE_TRIG = 0xF8,
>>> +};
>>> +
>>> +#define stm_channel_addr(drvdata, ch) (drvdata->chs.base + \
>>> + (ch * BYTES_PER_CHANNEL))
>>> +#define stm_channel_off(type, opts) (type & ~opts)
>>> +
>>> +static int boot_nr_channel;
>>> +
>>> +module_param_named(
>>> + boot_nr_channel, boot_nr_channel, int, S_IRUGO
>>> +);
>>> +
>>> +/**
>>> + * struct channel_space - central management entity for extended ports
>>> + * @base: memory mapped base address where channels start.
>>> + * @guaraneed: is the channel delivery guaranteed.
>>> + */
>>> +struct channel_space {
>>> + void __iomem *base;
>>> + unsigned long *guaranteed;
>>> +};
>>> +
>>> +/**
>>> + * struct stm_drvdata - specifics associated to an STM component
>>> + * @base: memory mapped base address for this component.
>>> + * @dev: the device entity associated to this component.
>>> + * @atclk: optional clock for the core parts of the STM.
>>> + * @csdev: component vitals needed by the framework.
>>> + * @spinlock: only one at a time pls.
>>> + * @chs: the channels accociated to this STM.
>>> + * @stm: structure associated to the generic STM interface.
>>> + * @enable: this STM is being used.
>>> + * @traceid: value of the current ID for this component.
>>> + * @write_max: Maximus bytes this STM can write at a time.
>>> + * @write_64bit: whether this STM supports 64 bit access.
>>> + * @stmsper: settings for register STMSPER.
>>> + * @stmspscr: settings for register STMSPSCR.
>>> + * @numsp: the total number of stimulus port support by this STM.
>>> + * @stmheer: settings for register STMHEER.
>>> + * @stmheter: settings for register STMHETER.
>>> + * @stmhebsr: settings for register STMHEBSR.
>>> + */
>>> +struct stm_drvdata {
>>> + void __iomem *base;
>>> + struct device *dev;
>>> + struct clk *atclk;
>>> + struct coresight_device *csdev;
>>> + spinlock_t spinlock;
>>> + struct channel_space chs;
>>> + struct stm_data stm;
>>> + bool enable;
>>> + u8 traceid;
>>> + u8 write_max;
>>> + u32 write_64bit;
>>> + u32 stmsper;
>>> + u32 stmspscr;
>>> + u32 numsp;
>>> + u32 stmheer;
>>> + u32 stmheter;
>>> + u32 stmhebsr;
>>> +};
>>> +
>>> +static void stm_hwevent_enable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + CS_UNLOCK(drvdata->base);
>>> +
>>> + writel_relaxed(drvdata->stmhebsr, drvdata->base + STMHEBSR);
>>> + writel_relaxed(drvdata->stmheter, drvdata->base + STMHETER);
>>> + writel_relaxed(drvdata->stmheer, drvdata->base + STMHEER);
>>> + writel_relaxed(0x01 | /* Enable HW event tracing */
>>> + 0x04, /* Error detection on event tracing */
>>> + drvdata->base + STMHEMCR);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +}
>>> +
>>> +static void stm_port_enable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + CS_UNLOCK(drvdata->base);
>>> + /* ATB trigger enable on direct writes to TRIG locations */
>>> + writel_relaxed(0x10,
>>> + drvdata->base + STMSPTRIGCSR);
>>> + writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
>>> + writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +}
>>> +
>>> +static void stm_enable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + if (drvdata->stmheer)
>>> + stm_hwevent_enable_hw(drvdata);
>>> +
>>> + stm_port_enable_hw(drvdata);
>>> +
>>> + CS_UNLOCK(drvdata->base);
>>> +
>>> + /* 4096 byte between synchronisation packets */
>>> + writel_relaxed(0xFFF, drvdata->base + STMSYNCR);
>>> + writel_relaxed((drvdata->traceid << 16 | /* trace id */
>>> + 0x02 | /* timestamp enable */
>>> + 0x01), /* global STM enable */
>>> + drvdata->base + STMTCSR);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +}
>>> +
>>> +static int stm_enable(struct coresight_device *csdev)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>>> +
>>> + pm_runtime_get_sync(drvdata->dev);
>>> +
>>> + spin_lock(&drvdata->spinlock);
>>> + stm_enable_hw(drvdata);
>>> + drvdata->enable = true;
>>> + spin_unlock(&drvdata->spinlock);
>>> +
>>> + dev_info(drvdata->dev, "STM tracing enabled\n");
>>> + return 0;
>>> +}
>>> +
>>> +static void stm_hwevent_disable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + CS_UNLOCK(drvdata->base);
>>> +
>>> + writel_relaxed(0x0, drvdata->base + STMHEMCR);
>>> + writel_relaxed(0x0, drvdata->base + STMHEER);
>>> + writel_relaxed(0x0, drvdata->base + STMHETER);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +}
>>> +
>>> +static void stm_port_disable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + CS_UNLOCK(drvdata->base);
>>> +
>>> + writel_relaxed(0x0, drvdata->base + STMSPER);
>>> + writel_relaxed(0x0, drvdata->base + STMSPTRIGCSR);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +}
>>> +
>>> +static void stm_disable_hw(struct stm_drvdata *drvdata)
>>> +{
>>> + u32 val;
>>> +
>>> + CS_UNLOCK(drvdata->base);
>>> +
>>> + val = readl_relaxed(drvdata->base + STMTCSR);
>>> + val &= ~0x1; /* clear global STM enable [0] */
>>> + writel_relaxed(val, drvdata->base + STMTCSR);
>>> +
>>> + CS_LOCK(drvdata->base);
>>> +
>>> + stm_port_disable_hw(drvdata);
>>> + if (drvdata->stmheer)
>>> + stm_hwevent_disable_hw(drvdata);
>>> +}
>>> +
>>> +static void stm_disable(struct coresight_device *csdev)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>>> +
>>> + spin_lock(&drvdata->spinlock);
>>> + stm_disable_hw(drvdata);
>>> + drvdata->enable = false;
>>> + spin_unlock(&drvdata->spinlock);
>>> +
>>> + /* Wait until the engine has completely stopped */
>>> + coresight_timeout(drvdata, STMTCSR, STMTCSR_BUSY_BIT, 0);
>>> +
>>> + pm_runtime_put(drvdata->dev);
>>> +
>>> + dev_info(drvdata->dev, "STM tracing disabled\n");
>>> +}
>>> +
>>> +static int stm_trace_id(struct coresight_device *csdev)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>>> +
>>> + return drvdata->traceid;
>>> +}
>>> +
>>> +static const struct coresight_ops_source stm_source_ops = {
>>> + .trace_id = stm_trace_id,
>>> + .enable = stm_enable,
>>> + .disable = stm_disable,
>>> +};
>>> +
>>> +static const struct coresight_ops stm_cs_ops = {
>>> + .source_ops = &stm_source_ops,
>>> +};
>>> +
>>> +static inline bool stm_addr_unaligned(const void *addr, u8 max)
>>> +{
>>> + return ((unsigned long)addr & (max - 1));
>>> +}
>>> +
>>> +static int stm_send(void *addr, const void *data, u32 size, u8 max)
>>> +{
>>> + u32 len = size;
>>> + u8 paload[8];
>>> +
>>> + if (stm_addr_unaligned(data, max)) {
>>> + memcpy(paload, data, size);
>>> + data = paload;
>>> + }
>>> +
>>> + /* now we are 64bit/32bit aligned */
>>> +#ifdef CONFIG_64BIT
>>> + if (size == 8)
>>> + writeq_relaxed(*(u64 *)data, addr);
>>> +#endif
>>
>> We probably don't need an #ifdef here. Checking the size of the
>> transfer against the fundamental data size will result in the same
>> outcome, i.e preventing 64 bit transfers on a 32 bit architecture. An
>> error (understandable by the caller) should probably be returned in
>> this case.
>
> In theory this is correct, but if the code is unreachable for non-32-bit architectures, why include it at all?

Why is this code unreachable on 64-bit systems? In this latest
revision "stm_send()" is used for both architecture.

>
>>> + if (size >= 4) {
>>> + writel_relaxed(*(u32 *)data, addr);
>>> + data += 4;
>>> + size -= 4;
>>> + }
>>> +
>>> + if (size >= 2) {
>>> + writew_relaxed(*(u16 *)data, addr);
>>> + data += 2;
>>> + size -= 2;
>>> + }
>>> +
>>> + if (size == 1)
>>> + writeb_relaxed(*(u8 *)data, addr);
>>> +
>>> + return len;
>>> +}
>
> The API for stm_data::packet (include/linux/stm.h) is not wholly clearly defined, but it does state "sends an STP packet," which I interpret as meaning exactly one packet and no more. This function (which is called from this module's implementation of stm_data::packet) will send multiple STP packets if called with a value that is not exactly 8, 4, 2, or 1.

I agree.

>
> To send only one packet, either:
>
> * These "if" statements are replaced with "else if" (as appropriate), and the function returns the size of data consumed; or

Please use a 'case' statement.

> * The stm_generic_packet() function (below) forces "size" to a power-of-two (<= write_max) before calling stm_send().

That will become a nightmare to debug/maintain - function stm_write()
[1] is already doing the count management.

[1]. http://lxr.free-electrons.com/source/drivers/hwtracing/stm/core.c#L383

>
>>> +static int stm_generic_link(struct stm_data *stm_data,
>>> + unsigned int master, unsigned int channel)
>>> +{
>>> + struct stm_drvdata *drvdata = container_of(stm_data,
>>> + struct stm_drvdata, stm);
>>> + if (!drvdata || !drvdata->csdev)
>>> + return -EINVAL;
>>> +
>>> + return coresight_enable(drvdata->csdev);
>>> +}
>>> +
>>> +static void stm_generic_unlink(struct stm_data *stm_data,
>>> + unsigned int master, unsigned int channel)
>>> +{
>>> + struct stm_drvdata *drvdata = container_of(stm_data,
>>> + struct stm_drvdata, stm);
>>> + if (!drvdata || !drvdata->csdev)
>>> + return;
>>> +
>>> + stm_disable(drvdata->csdev);
>>> +}
>>> +
>>> +static long stm_generic_set_options(struct stm_data *stm_data,
>>> + unsigned int master,
>>> + unsigned int channel,
>>> + unsigned int nr_chans,
>>> + unsigned long options)
>>> +{
>>> + struct stm_drvdata *drvdata = container_of(stm_data,
>>> + struct stm_drvdata, stm);
>>> + if (!(drvdata && drvdata->enable))
>>> + return -EINVAL;
>>> +
>>> + if (channel >= drvdata->numsp)
>>> + return -EINVAL;
>>> +
>>> + switch (options) {
>>> + case STM_OPTION_GUARANTEED:
>>> + set_bit(channel, drvdata->chs.guaranteed);
>>> + break;
>>> +
>>> + case STM_OPTION_INVARIANT:
>>> + clear_bit(channel, drvdata->chs.guaranteed);
>>> + break;
>>> +
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static long stm_generic_get_options(struct stm_data *stm_data,
>>> + unsigned int master,
>>> + unsigned int channel,
>>> + unsigned int nr_chans,
>>> + u64 *options)
>>> +{
>>> + struct stm_drvdata *drvdata = container_of(stm_data,
>>> + struct stm_drvdata, stm);
>>> + if (!(drvdata && drvdata->enable))
>>> + return -EINVAL;
>>> +
>>> + if (channel >= drvdata->numsp)
>>> + return -EINVAL;
>>> +
>>> + switch (*options) {
>>> + case STM_OPTION_GUARANTEED:
>>> + *options = test_bit(channel, drvdata->chs.guaranteed);
>>> + break;
>>> +
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static ssize_t stm_generic_packet(struct stm_data *stm_data,
>>> + unsigned int master,
>>> + unsigned int channel,
>>> + unsigned int packet,
>>> + unsigned int flags,
>>> + unsigned int size,
>>> + const unsigned char *payload)
>>> +{
>>> + unsigned long ch_addr;
>>> + struct stm_drvdata *drvdata = container_of(stm_data,
>>> + struct stm_drvdata, stm);
>>> +
>>> + if (!(drvdata && drvdata->enable))
>>> + return 0;
>>> +
>>> + if (channel >= drvdata->numsp)
>>> + return 0;
>>> +
>>> + ch_addr = (unsigned long)stm_channel_addr(drvdata, channel);
>>> +
>>> + flags = (flags == STP_PACKET_TIMESTAMPED) ? STM_FLAG_TIMESTAMPED : 0;
>>> + flags |= test_bit(channel, drvdata->chs.guaranteed) ?
>>> + STM_FLAG_GUARANTEED : 0;
>>> +
>>> + if (size > drvdata->write_max)
>>> + size = drvdata->write_max;
>>> +
>>> + switch (packet) {
>>> + case STP_PACKET_FLAG:
>>> + ch_addr |= stm_channel_off(STM_PKT_TYPE_FLAG, flags);
>>> +
>>> + /* the generic STM API set a size of zero on flag packets. */
>>> + size = 1;
>>> + break;
>>> +
>>> + case STP_PACKET_DATA:
>>> + ch_addr |= stm_channel_off(STM_PKT_TYPE_DATA, flags);
>>> + break;
>>> +
>>> + default:
>>> + return 0;
>>> + }
>>> +
>>> + return stm_send((void *)ch_addr, payload, size, drvdata->write_max);
>>> +}
>>> +
>>> +static ssize_t hwevent_enable_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val = drvdata->stmheer;
>>> +
>>> + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>>> +}
>>> +
>>> +static ssize_t hwevent_enable_store(struct device *dev,
>>> + struct device_attribute *attr,
>>> + const char *buf, size_t size)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val;
>>> + int ret = 0;
>>> +
>>> + ret = kstrtoul(buf, 16, &val);
>>> + if (ret)
>>> + return -EINVAL;
>>> +
>>> + drvdata->stmheer = val;
>>> + /* HW event enable and trigger go hand in hand */
>>> + drvdata->stmheter = val;
>>> +
>>> + return size;
>>> +}
>>> +static DEVICE_ATTR_RW(hwevent_enable);
>>> +
>>> +static ssize_t hwevent_select_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val = drvdata->stmhebsr;
>>> +
>>> + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>>> +}
>>> +
>>> +static ssize_t hwevent_select_store(struct device *dev,
>>> + struct device_attribute *attr,
>>> + const char *buf, size_t size)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val;
>>> + int ret = 0;
>>> +
>>> + ret = kstrtoul(buf, 16, &val);
>>> + if (ret)
>>> + return -EINVAL;
>>> +
>>> + drvdata->stmhebsr = val;
>>> +
>>> + return size;
>>> +}
>>> +static DEVICE_ATTR_RW(hwevent_select);
>>> +
>>> +static ssize_t port_select_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val;
>>> +
>>> + if (!drvdata->enable) {
>>> + val = drvdata->stmspscr;
>>> + } else {
>>> + spin_lock(&drvdata->spinlock);
>>> + val = readl_relaxed(drvdata->base + STMSPSCR);
>>> + spin_unlock(&drvdata->spinlock);
>>> + }
>>> +
>>> + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>>> +}
>>> +
>>> +static ssize_t port_select_store(struct device *dev,
>>> + struct device_attribute *attr,
>>> + const char *buf, size_t size)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val, stmsper;
>>> + int ret = 0;
>>> +
>>> + ret = kstrtoul(buf, 16, &val);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + spin_lock(&drvdata->spinlock);
>>> + drvdata->stmspscr = val;
>>> +
>>> + if (drvdata->enable) {
>>> + CS_UNLOCK(drvdata->base);
>>> + /* Process as per ARM's TRM recommendation */
>>> + stmsper = readl_relaxed(drvdata->base + STMSPER);
>>> + writel_relaxed(0x0, drvdata->base + STMSPER);
>>> + writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
>>> + writel_relaxed(stmsper, drvdata->base + STMSPER);
>>> + CS_LOCK(drvdata->base);
>>> + }
>>> + spin_unlock(&drvdata->spinlock);
>>> +
>>> + return size;
>>> +}
>>> +static DEVICE_ATTR_RW(port_select);
>>> +
>>> +static ssize_t port_enable_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val;
>>> +
>>> + if (!drvdata->enable) {
>>> + val = drvdata->stmsper;
>>> + } else {
>>> + spin_lock(&drvdata->spinlock);
>>> + val = readl_relaxed(drvdata->base + STMSPER);
>>> + spin_unlock(&drvdata->spinlock);
>>> + }
>>> +
>>> + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>>> +}
>>> +
>>> +static ssize_t port_enable_store(struct device *dev,
>>> + struct device_attribute *attr,
>>> + const char *buf, size_t size)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> + unsigned long val;
>>> + int ret = 0;
>>> +
>>> + ret = kstrtoul(buf, 16, &val);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + spin_lock(&drvdata->spinlock);
>>> + drvdata->stmsper = val;
>>> +
>>> + if (drvdata->enable) {
>>> + CS_UNLOCK(drvdata->base);
>>> + writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
>>> + CS_LOCK(drvdata->base);
>>> + }
>>> + spin_unlock(&drvdata->spinlock);
>>> +
>>> + return size;
>>> +}
>>> +static DEVICE_ATTR_RW(port_enable);
>>> +
>>> +static ssize_t traceid_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + unsigned long val;
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> +
>>> + val = drvdata->traceid;
>>> + return sprintf(buf, "%#lx\n", val);
>>> +}
>>> +
>>> +static ssize_t traceid_store(struct device *dev,
>>> + struct device_attribute *attr,
>>> + const char *buf, size_t size)
>>> +{
>>> + int ret;
>>> + unsigned long val;
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
>>> +
>>> + ret = kstrtoul(buf, 16, &val);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* traceid field is 7bit wide on STM32 */
>>> + drvdata->traceid = val & 0x7f;
>>> + return size;
>>> +}
>>> +static DEVICE_ATTR_RW(traceid);
>>> +
>>> +#define coresight_simple_func(type, name, offset) \
>>> +static ssize_t name##_show(struct device *_dev, \
>>> + struct device_attribute *attr, char *buf) \
>>> +{ \
>>> + type *drvdata = dev_get_drvdata(_dev->parent); \
>>> + return scnprintf(buf, PAGE_SIZE, "0x%08x\n", \
>>> + readl_relaxed(drvdata->base + offset)); \
>>> +} \
>>> +DEVICE_ATTR_RO(name)
>>> +
>>> +#define coresight_stm_simple_func(name, offset) \
>>> + coresight_simple_func(struct stm_drvdata, name, offset)
>>> +
>>> +coresight_stm_simple_func(tcsr, STMTCSR);
>>> +coresight_stm_simple_func(tsfreqr, STMTSFREQR);
>>> +coresight_stm_simple_func(syncr, STMSYNCR);
>>> +coresight_stm_simple_func(sper, STMSPER);
>>> +coresight_stm_simple_func(spter, STMSPTER);
>>> +coresight_stm_simple_func(privmaskr, STMPRIVMASKR);
>>> +coresight_stm_simple_func(spscr, STMSPSCR);
>>> +coresight_stm_simple_func(spmscr, STMSPMSCR);
>>> +coresight_stm_simple_func(spfeat1r, STMSPFEAT1R);
>>> +coresight_stm_simple_func(spfeat2r, STMSPFEAT2R);
>>> +coresight_stm_simple_func(spfeat3r, STMSPFEAT3R);
>>> +coresight_stm_simple_func(devid, CORESIGHT_DEVID);
>>> +
>>> +static struct attribute *coresight_stm_attrs[] = {
>>> + &dev_attr_hwevent_enable.attr,
>>> + &dev_attr_hwevent_select.attr,
>>> + &dev_attr_port_enable.attr,
>>> + &dev_attr_port_select.attr,
>>> + &dev_attr_traceid.attr,
>>> + NULL,
>>> +};
>>> +
>>> +static struct attribute *coresight_stm_mgmt_attrs[] = {
>>> + &dev_attr_tcsr.attr,
>>> + &dev_attr_tsfreqr.attr,
>>> + &dev_attr_syncr.attr,
>>> + &dev_attr_sper.attr,
>>> + &dev_attr_spter.attr,
>>> + &dev_attr_privmaskr.attr,
>>> + &dev_attr_spscr.attr,
>>> + &dev_attr_spmscr.attr,
>>> + &dev_attr_spfeat1r.attr,
>>> + &dev_attr_spfeat2r.attr,
>>> + &dev_attr_spfeat3r.attr,
>>> + &dev_attr_devid.attr,
>>> + NULL,
>>> +};
>>> +
>>> +static const struct attribute_group coresight_stm_group = {
>>> + .attrs = coresight_stm_attrs,
>>> +};
>>> +
>>> +static const struct attribute_group coresight_stm_mgmt_group = {
>>> + .attrs = coresight_stm_mgmt_attrs,
>>> + .name = "mgmt",
>>> +};
>>> +
>>> +static const struct attribute_group *coresight_stm_groups[] = {
>>> + &coresight_stm_group,
>>> + &coresight_stm_mgmt_group,
>>> + NULL,
>>> +};
>>> +
>>> +static int stm_get_resource_byname(struct device_node *np,
>>> + char *ch_base, struct resource *res)
>>> +{
>>> + const char *name = NULL;
>>> + int index = 0, found = 0;
>>> +
>>> + while (!of_property_read_string_index(np, "reg-names", index, &name)) {
>>> + if (strcmp(ch_base, name)) {
>>> + index++;
>>> + continue;
>>> + }
>>> +
>>> + /* We have a match and @index is where it's at */
>>> + found = 1;
>>> + break;
>>> + }
>>> +
>>> + if (!found)
>>> + return -EINVAL;
>>> +
>>> + return of_address_to_resource(np, index, res);
>>> +}
>>> +
>>> +static u32 stm_fundamental_data_size(struct stm_drvdata *drvdata)
>>> +{
>>> + u32 stmspfeat2r;
>>> +
>>> + stmspfeat2r = readl_relaxed(drvdata->base + STMSPFEAT2R);
>>> + return BMVAL(stmspfeat2r, 12, 15);
>>> +}
>>> +
>>> +static u32 stm_num_stimulus_port(struct stm_drvdata *drvdata)
>>> +{
>>> + u32 numsp;
>>> +
>>> + numsp = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
>>> + /*
>>> + * NUMPS in STMDEVID is 17 bit long and if equal to 0x0,
>>> + * 32 stimulus ports are supported.
>>> + */
>>> + numsp &= 0x1ffff;
>>> + if (!numsp)
>>> + numsp = STM_32_CHANNEL;
>>> + return numsp;
>>> +}
>>> +
>>> +static void stm_init_default_data(struct stm_drvdata *drvdata)
>>> +{
>>> + /* Don't use port selection */
>>> + drvdata->stmspscr = 0x0;
>>> + /*
>>> + * Enable all channel regardless of their number. When port
>>> + * selection isn't used (see above) STMSPER applies to all
>>> + * 32 channel group available, hence setting all 32 bits to 1
>>> + */
>>> + drvdata->stmsper = ~0x0;
>>> +
>>> + /*
>>> + * Select arbitrary value to start with. If there is a conflict
>>> + * with other tracers the framework will deal with it.
>>> + */
>>> + drvdata->traceid = 0x20;
>>> +
>>> + /* Set invariant transaction timing on all channels */
>>> + bitmap_clear(drvdata->chs.guaranteed, 0, drvdata->numsp);
>>> +}
>>> +
>>> +static void stm_init_generic_data(struct stm_drvdata *drvdata)
>>> +{
>>> + drvdata->stm.name = dev_name(drvdata->dev);
>>> + drvdata->stm.mstatic = true;
>>> + drvdata->stm.sw_nchannels = drvdata->numsp;
>>> + drvdata->stm.packet = stm_generic_packet;
>>> + drvdata->stm.link = stm_generic_link;
>>> + drvdata->stm.unlink = stm_generic_unlink;
>>> + drvdata->stm.set_options = stm_generic_set_options;
>>> + drvdata->stm.get_options = stm_generic_get_options;
>>> +}
>>> +
>>> +static int stm_probe(struct amba_device *adev, const struct amba_id *id)
>>> +{
>>> + int ret;
>>> + void __iomem *base;
>>> + unsigned long *guaranteed;
>>> + struct device *dev = &adev->dev;
>>> + struct coresight_platform_data *pdata = NULL;
>>> + struct stm_drvdata *drvdata;
>>> + struct resource *res = &adev->res;
>>> + struct resource ch_res;
>>> + size_t res_size, bitmap_size;
>>> + struct coresight_desc *desc;
>>> + struct device_node *np = adev->dev.of_node;
>>> +
>>> + if (np) {
>>> + pdata = of_get_coresight_platform_data(dev, np);
>>> + if (IS_ERR(pdata))
>>> + return PTR_ERR(pdata);
>>> + adev->dev.platform_data = pdata;
>>> + }
>>> + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
>>> + if (!drvdata)
>>> + return -ENOMEM;
>>> +
>>> + drvdata->dev = &adev->dev;
>>> + drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
>>> + if (!IS_ERR(drvdata->atclk)) {
>>> + ret = clk_prepare_enable(drvdata->atclk);
>>> + if (ret)
>>> + return ret;
>>> + }
>>> + dev_set_drvdata(dev, drvdata);
>>> +
>>> + base = devm_ioremap_resource(dev, res);
>>> + if (IS_ERR(base))
>>> + return PTR_ERR(base);
>>> + drvdata->base = base;
>>> +
>>> + ret = stm_get_resource_byname(np, "stm-stimulus-base", &ch_res);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + base = devm_ioremap_resource(dev, &ch_res);
>>> + if (IS_ERR(base))
>>> + return PTR_ERR(base);
>>> + drvdata->chs.base = base;
>>> +
>>> + drvdata->write_max = sizeof(u32);
>>
>> Isn't the fundamental data size the maximum an architecture can stand?
>> Why not simply use that rather than adding another variable?
>>
>>> + drvdata->write_64bit = stm_fundamental_data_size(drvdata);
>>> +
>>> +#ifndef CONFIG_64BIT
>>> + if (drvdata->write_64bit)
>>> + drvdata->write_max = sizeof(u64);
>>> +#endif
>
> It is a bit odd that this code is using sizeof(u64) / sizeof(u32) here, when it is using 8 / 4 explicitly in the functions above.
>
>>
>> In most cases the fundamental data size will follow the architecture
>> size, i.e, 32 bit architecture with 32 bit fundamental data size, 64
>> bit architecture with 64 bit fundamental data size. A fundamental
>> data size of 32 is also possible on a 64 bit architecture.
>>
>> What needs to be prevented is a 32 bit architecture with a fundamental
>> data size of 64. In those cases the fundamental data size should be
>> adjusted to be 32 bit. To do that I suggest to modify
>> stm_fundamental_data_size() to probe the STM's fundamental data size
>> but to adjust it down if on a 32 bit system. Knowing whether running
>> on a 32/64 bit system is easy when using the IS_ENABLED() macro.
>
> Agreed. For ARM, 64-bit writes to the STM are supported only if BOTH the STM supports 64-bit data and the processor is in 64-bit execution state. Otherwise, the largest size is 32 bits. You are likely to see both 64-bit STM from 32-bit execution state, and 32-bit STM on a SoC with a 64-bit ARM processor.
>
>>> +
>>> + if (boot_nr_channel) {
>>> + drvdata->numsp = boot_nr_channel;
>>> + res_size = min((resource_size_t)(boot_nr_channel *
>>> + BYTES_PER_CHANNEL), resource_size(res));
>>> + } else {
>>> + drvdata->numsp = stm_num_stimulus_port(drvdata);
>>> + res_size = min((resource_size_t)(drvdata->numsp *
>>> + BYTES_PER_CHANNEL), resource_size(res));
>>> + }
>>> + bitmap_size = BITS_TO_LONGS(drvdata->numsp) * sizeof(long);
>>> +
>>> + guaranteed = devm_kzalloc(dev, bitmap_size, GFP_KERNEL);
>>> + if (!guaranteed)
>>> + return -ENOMEM;
>>> + drvdata->chs.guaranteed = guaranteed;
>>> +
>>> + spin_lock_init(&drvdata->spinlock);
>>> +
>>> + stm_init_default_data(drvdata);
>>> + stm_init_generic_data(drvdata);
>>> +
>>> + if (stm_register_device(dev, &drvdata->stm, THIS_MODULE)) {
>>> + dev_info(dev,
>>> + "stm_register_device failed, probing deffered\n");
>>> + return -EPROBE_DEFER;
>>> + }
>>> +
>>> + desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
>>> + if (!desc) {
>>> + ret = -ENOMEM;
>>> + goto stm_unregister;
>>> + }
>>> +
>>> + desc->type = CORESIGHT_DEV_TYPE_SOURCE;
>>> + desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE;
>>> + desc->ops = &stm_cs_ops;
>>> + desc->pdata = pdata;
>>> + desc->dev = dev;
>>> + desc->groups = coresight_stm_groups;
>>> + drvdata->csdev = coresight_register(desc);
>>> + if (IS_ERR(drvdata->csdev)) {
>>> + ret = PTR_ERR(drvdata->csdev);
>>> + goto stm_unregister;
>>> + }
>>> +
>>> + pm_runtime_put(&adev->dev);
>>> +
>>> + dev_info(dev, "%s initialized\n", (char *)id->data);
>>> + return 0;
>>> +
>>> +stm_unregister:
>>> + stm_unregister_device(&drvdata->stm);
>>> + return ret;
>>> +}
>>> +
>>> +static int stm_remove(struct amba_device *adev)
>>> +{
>>> + struct stm_drvdata *drvdata = amba_get_drvdata(adev);
>>> +
>>> + stm_unregister_device(&drvdata->stm);
>>> + coresight_unregister(drvdata->csdev);
>>> + return 0;
>>> +}
>>
>> The xyz_remove() functions is not needed for coresight devices -
>> unbinding a device from its driver will no longer be possible in the
>> 4.6 cycle.
>>
>>> +
>>> +#ifdef CONFIG_PM
>>> +static int stm_runtime_suspend(struct device *dev)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev);
>>> +
>>> + if (drvdata && !IS_ERR(drvdata->atclk))
>>> + clk_disable_unprepare(drvdata->atclk);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int stm_runtime_resume(struct device *dev)
>>> +{
>>> + struct stm_drvdata *drvdata = dev_get_drvdata(dev);
>>> +
>>> + if (drvdata && !IS_ERR(drvdata->atclk))
>>> + clk_prepare_enable(drvdata->atclk);
>>> +
>>> + return 0;
>>> +}
>>> +#endif
>>> +
>>> +static const struct dev_pm_ops stm_dev_pm_ops = {
>>> + SET_RUNTIME_PM_OPS(stm_runtime_suspend, stm_runtime_resume, NULL)
>>> +};
>>> +
>>> +static struct amba_id stm_ids[] = {
>>> + {
>>> + .id = 0x0003b962,
>>> + .mask = 0x0003ffff,
>>> + .data = "STM32",
>>> + },
>>> + { 0, 0},
>>> +};
>>> +
>>> +static struct amba_driver stm_driver = {
>>> + .drv = {
>>> + .name = "coresight-stm",
>>> + .owner = THIS_MODULE,
>>> + .pm = &stm_dev_pm_ops,
>>> + },
>>> + .probe = stm_probe,
>>> + .remove = stm_remove,
>>> + .id_table = stm_ids,
>>> +};
>>> +
>>> +module_amba_driver(stm_driver);
>>> +
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_DESCRIPTION("CoreSight System Trace Macrocell driver");
>>> diff --git a/include/linux/coresight-stm.h b/include/linux/coresight-stm.h
>>> new file mode 100644
>>> index 0000000..a978bb8
>>> --- /dev/null
>>> +++ b/include/linux/coresight-stm.h
>>> @@ -0,0 +1,6 @@
>>> +#ifndef __LINUX_CORESIGHT_STM_H_
>>> +#define __LINUX_CORESIGHT_STM_H_
>>> +
>>> +#include <uapi/linux/coresight-stm.h>
>>> +
>>> +#endif
>>> diff --git a/include/uapi/linux/coresight-stm.h b/include/uapi/linux/coresight-stm.h
>>> new file mode 100644
>>> index 0000000..fa35f0b
>>> --- /dev/null
>>> +++ b/include/uapi/linux/coresight-stm.h
>>> @@ -0,0 +1,12 @@
>>> +#ifndef __UAPI_CORESIGHT_STM_H_
>>> +#define __UAPI_CORESIGHT_STM_H_
>>> +
>>> +#define STM_FLAG_TIMESTAMPED BIT(3)
>>> +#define STM_FLAG_GUARANTEED BIT(7)
>>> +
>>> +enum {
>>> + STM_OPTION_GUARANTEED = 0,
>>> + STM_OPTION_INVARIANT,
>>> +};
>>> +
>>> +#endif
>>> --
>>> 1.9.1
>>>
>
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