[PATCH V3 6/6] coresight-stm: adding driver for CoreSight STM component
Mathieu Poirier
mathieu.poirier at linaro.org
Thu Feb 11 08:59:51 PST 2016
On 6 February 2016 at 04:04, Chunyan Zhang <zhang.chunyan at linaro.org> wrote:
> From: Pratik Patel <pratikp at codeaurora.org>
>
> 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 at codeaurora.org>
> Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
> Signed-off-by: Chunyan Zhang <zhang.chunyan at linaro.org>
> ---
> .../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 at linaro.org>
> +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 at linaro.org>
> +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 at linaro.org>
> +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 at linaro.org>
> +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 at linaro.org>
> +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 at linaro.org>
> +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 at linaro.org>
> +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 at genericarmv8:~# ls /sys/bus/coresight/devices/20100000.stm
> +enable_source hwevent_select port_enable subsystem uevent
> +hwevent_enable mgmt port_select traceid
> +root at genericarmv8:~#
> +
> +Like any other source a sink needs to be identified and the STM enabled before
> +being used:
> +
> +root at genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20010000.etf/enable_sink
> +root at 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 at genericarmv8:~# ls -l /dev/20100000.stm
> +crw------- 1 root root 10, 61 Jan 3 18:11 /dev/20100000.stm
> +root at 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 at codeaurora.org>
> + *
> + * Serious refactoring, code cleanup and upgrading to the Coresight upstream
> + * framework by Mathieu Poirier
> + * (C) 2015-2016 Mathieu Poirier <mathieu.poirier at linaro.org>
> + *
> + * Guaranteed timing and support for various packet type coming from the
> + * generic STM API by Chunyan Zhang
> + * (C) 2015-2016 Chunyan Zhang <zhang.chunyan at linaro.org>
> + */
> +#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.
> + 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;
> +}
> +
> +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
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.
> +
> + 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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