Add MIPI OST protocol support for stm to format the traces.
Framework copied from drivers/hwtracing/stm.p-sys-t.c as of
commit d69d5e83110f ("stm class: Add MIPI SyS-T protocol
support").
Signed-off-by: Tingwei Zhang <[email protected]>
Signed-off-by: Mao Jinlong <[email protected]>
---
drivers/hwtracing/stm/Kconfig | 14 +++++
drivers/hwtracing/stm/Makefile | 2 +
drivers/hwtracing/stm/p_ost.c | 95 ++++++++++++++++++++++++++++++++++
3 files changed, 111 insertions(+)
create mode 100644 drivers/hwtracing/stm/p_ost.c
diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig
index aad594fe79cc..0b52901125f7 100644
--- a/drivers/hwtracing/stm/Kconfig
+++ b/drivers/hwtracing/stm/Kconfig
@@ -41,6 +41,20 @@ config STM_PROTO_SYS_T
If you don't know what this is, say N.
+config STM_PROTO_OST
+ tristate "MIPI OST STM framing protocol driver"
+ default CONFIG_STM
+ help
+ This is an implementation of MIPI OST protocol to be used
+ over the STP transport. In addition to the data payload, it
+ also carries additional metadata for entity, better
+ means of trace source identification, etc.
+
+ The receiving side must be able to decode this protocol in
+ addition to the MIPI STP, in order to extract the data.
+
+ If you don't know what this is, say N.
+
config STM_DUMMY
tristate "Dummy STM driver"
help
diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile
index 1692fcd29277..715fc721891e 100644
--- a/drivers/hwtracing/stm/Makefile
+++ b/drivers/hwtracing/stm/Makefile
@@ -5,9 +5,11 @@ stm_core-y := core.o policy.o
obj-$(CONFIG_STM_PROTO_BASIC) += stm_p_basic.o
obj-$(CONFIG_STM_PROTO_SYS_T) += stm_p_sys-t.o
+obj-$(CONFIG_STM_PROTO_OST) += stm_p_ost.o
stm_p_basic-y := p_basic.o
stm_p_sys-t-y := p_sys-t.o
+stm_p_ost-y := p_ost.o
obj-$(CONFIG_STM_DUMMY) += dummy_stm.o
diff --git a/drivers/hwtracing/stm/p_ost.c b/drivers/hwtracing/stm/p_ost.c
new file mode 100644
index 000000000000..2ca1a3fda57f
--- /dev/null
+++ b/drivers/hwtracing/stm/p_ost.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copied from drivers/hwtracing/stm.p-sys-t.c as of commit d69d5e83110f
+ * ("stm class: Add MIPI SyS-T protocol support").
+ *
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2020 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2018, Intel Corporation.
+ *
+ * MIPI OST framing protocol for STM devices.
+ */
+
+#include <linux/configfs.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/stm.h>
+#include <linux/sched/clock.h>
+#include "stm.h"
+
+#define OST_TOKEN_STARTSIMPLE (0x10)
+#define OST_VERSION_MIPI1 (0x10 << 8)
+#define OST_ENTITY_FTRACE (0x01 << 16)
+#define OST_CONTROL_PROTOCOL (0x0 << 24)
+
+#define DATA_HEADER (OST_TOKEN_STARTSIMPLE | OST_VERSION_MIPI1 | \
+ OST_ENTITY_FTRACE | OST_CONTROL_PROTOCOL)
+
+#define STM_MAKE_VERSION(ma, mi) ((ma << 8) | mi)
+#define STM_HEADER_MAGIC (0x5953)
+
+static ssize_t notrace ost_write(struct stm_data *data,
+ struct stm_output *output, unsigned int chan,
+ const char *buf, size_t count)
+{
+ unsigned int c = output->channel + chan;
+ unsigned int m = output->master;
+ const unsigned char nil = 0;
+ u32 header = DATA_HEADER;
+ u8 trc_hdr[24];
+ ssize_t sz;
+
+ /*
+ * STP framing rules for OST frames:
+ * * the first packet of the OST frame is marked;
+ * * the last packet is a FLAG.
+ */
+ /* Message layout: HEADER / DATA / TAIL */
+ /* HEADER */
+
+ sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_MARKED,
+ 4, (u8 *)&header);
+ if (sz <= 0)
+ return sz;
+ *(uint16_t *)(trc_hdr) = STM_MAKE_VERSION(0, 3);
+ *(uint16_t *)(trc_hdr + 2) = STM_HEADER_MAGIC;
+ *(uint32_t *)(trc_hdr + 4) = raw_smp_processor_id();
+ *(uint64_t *)(trc_hdr + 8) = sched_clock();
+ *(uint64_t *)(trc_hdr + 16) = task_tgid_nr(get_current());
+ sz = stm_data_write(data, m, c, false, trc_hdr, sizeof(trc_hdr));
+ if (sz <= 0)
+ return sz;
+
+ /* DATA */
+ sz = stm_data_write(data, m, c, false, buf, count);
+
+ /* TAIL */
+ if (sz > 0)
+ data->packet(data, m, c, STP_PACKET_FLAG,
+ STP_PACKET_TIMESTAMPED, 0, &nil);
+
+ return sz;
+}
+
+static const struct stm_protocol_driver ost_pdrv = {
+ .owner = THIS_MODULE,
+ .name = "p_ost",
+ .write = ost_write,
+};
+
+static int ost_stm_init(void)
+{
+ return stm_register_protocol(&ost_pdrv);
+}
+
+static void ost_stm_exit(void)
+{
+ stm_unregister_protocol(&ost_pdrv);
+}
+
+module_init(ost_stm_init);
+module_exit(ost_stm_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MIPI Open System Trace STM framing protocol driver");
--
2.39.0
Hi Reviewers,
Could you please help to review this patch ?
Thanks
Jinlong Mao
On 2/8/2023 8:40 PM, Mao Jinlong wrote:
> Add MIPI OST protocol support for stm to format the traces.
> Framework copied from drivers/hwtracing/stm.p-sys-t.c as of
> commit d69d5e83110f ("stm class: Add MIPI SyS-T protocol
> support").
>
> Signed-off-by: Tingwei Zhang <[email protected]>
> Signed-off-by: Mao Jinlong <[email protected]>
> ---
> drivers/hwtracing/stm/Kconfig | 14 +++++
> drivers/hwtracing/stm/Makefile | 2 +
> drivers/hwtracing/stm/p_ost.c | 95 ++++++++++++++++++++++++++++++++++
> 3 files changed, 111 insertions(+)
> create mode 100644 drivers/hwtracing/stm/p_ost.c
>
> diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig
> index aad594fe79cc..0b52901125f7 100644
> --- a/drivers/hwtracing/stm/Kconfig
> +++ b/drivers/hwtracing/stm/Kconfig
> @@ -41,6 +41,20 @@ config STM_PROTO_SYS_T
>
> If you don't know what this is, say N.
>
> +config STM_PROTO_OST
> + tristate "MIPI OST STM framing protocol driver"
> + default CONFIG_STM
> + help
> + This is an implementation of MIPI OST protocol to be used
> + over the STP transport. In addition to the data payload, it
> + also carries additional metadata for entity, better
> + means of trace source identification, etc.
> +
> + The receiving side must be able to decode this protocol in
> + addition to the MIPI STP, in order to extract the data.
> +
> + If you don't know what this is, say N.
> +
> config STM_DUMMY
> tristate "Dummy STM driver"
> help
> diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile
> index 1692fcd29277..715fc721891e 100644
> --- a/drivers/hwtracing/stm/Makefile
> +++ b/drivers/hwtracing/stm/Makefile
> @@ -5,9 +5,11 @@ stm_core-y := core.o policy.o
>
> obj-$(CONFIG_STM_PROTO_BASIC) += stm_p_basic.o
> obj-$(CONFIG_STM_PROTO_SYS_T) += stm_p_sys-t.o
> +obj-$(CONFIG_STM_PROTO_OST) += stm_p_ost.o
>
> stm_p_basic-y := p_basic.o
> stm_p_sys-t-y := p_sys-t.o
> +stm_p_ost-y := p_ost.o
>
> obj-$(CONFIG_STM_DUMMY) += dummy_stm.o
>
> diff --git a/drivers/hwtracing/stm/p_ost.c b/drivers/hwtracing/stm/p_ost.c
> new file mode 100644
> index 000000000000..2ca1a3fda57f
> --- /dev/null
> +++ b/drivers/hwtracing/stm/p_ost.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copied from drivers/hwtracing/stm.p-sys-t.c as of commit d69d5e83110f
> + * ("stm class: Add MIPI SyS-T protocol support").
> + *
> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> + * Copyright (c) 2020 The Linux Foundation. All rights reserved.
> + * Copyright (c) 2018, Intel Corporation.
> + *
> + * MIPI OST framing protocol for STM devices.
> + */
> +
> +#include <linux/configfs.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/slab.h>
> +#include <linux/stm.h>
> +#include <linux/sched/clock.h>
> +#include "stm.h"
> +
> +#define OST_TOKEN_STARTSIMPLE (0x10)
> +#define OST_VERSION_MIPI1 (0x10 << 8)
> +#define OST_ENTITY_FTRACE (0x01 << 16)
> +#define OST_CONTROL_PROTOCOL (0x0 << 24)
> +
> +#define DATA_HEADER (OST_TOKEN_STARTSIMPLE | OST_VERSION_MIPI1 | \
> + OST_ENTITY_FTRACE | OST_CONTROL_PROTOCOL)
> +
> +#define STM_MAKE_VERSION(ma, mi) ((ma << 8) | mi)
> +#define STM_HEADER_MAGIC (0x5953)
> +
> +static ssize_t notrace ost_write(struct stm_data *data,
> + struct stm_output *output, unsigned int chan,
> + const char *buf, size_t count)
> +{
> + unsigned int c = output->channel + chan;
> + unsigned int m = output->master;
> + const unsigned char nil = 0;
> + u32 header = DATA_HEADER;
> + u8 trc_hdr[24];
> + ssize_t sz;
> +
> + /*
> + * STP framing rules for OST frames:
> + * * the first packet of the OST frame is marked;
> + * * the last packet is a FLAG.
> + */
> + /* Message layout: HEADER / DATA / TAIL */
> + /* HEADER */
> +
> + sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_MARKED,
> + 4, (u8 *)&header);
> + if (sz <= 0)
> + return sz;
> + *(uint16_t *)(trc_hdr) = STM_MAKE_VERSION(0, 3);
> + *(uint16_t *)(trc_hdr + 2) = STM_HEADER_MAGIC;
> + *(uint32_t *)(trc_hdr + 4) = raw_smp_processor_id();
> + *(uint64_t *)(trc_hdr + 8) = sched_clock();
> + *(uint64_t *)(trc_hdr + 16) = task_tgid_nr(get_current());
> + sz = stm_data_write(data, m, c, false, trc_hdr, sizeof(trc_hdr));
> + if (sz <= 0)
> + return sz;
> +
> + /* DATA */
> + sz = stm_data_write(data, m, c, false, buf, count);
> +
> + /* TAIL */
> + if (sz > 0)
> + data->packet(data, m, c, STP_PACKET_FLAG,
> + STP_PACKET_TIMESTAMPED, 0, &nil);
> +
> + return sz;
> +}
> +
> +static const struct stm_protocol_driver ost_pdrv = {
> + .owner = THIS_MODULE,
> + .name = "p_ost",
> + .write = ost_write,
> +};
> +
> +static int ost_stm_init(void)
> +{
> + return stm_register_protocol(&ost_pdrv);
> +}
> +
> +static void ost_stm_exit(void)
> +{
> + stm_unregister_protocol(&ost_pdrv);
> +}
> +
> +module_init(ost_stm_init);
> +module_exit(ost_stm_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("MIPI Open System Trace STM framing protocol driver");
Mao Jinlong <[email protected]> writes:
> Add MIPI OST protocol support for stm to format the traces.
Missing an explanation of what OST is, what it's used for, how it is
different from the SyS-T and others.
> Framework copied from drivers/hwtracing/stm.p-sys-t.c as of
You mean stm/p_sys-t.c. Also, it's not a framework, it's a driver.
> commit d69d5e83110f ("stm class: Add MIPI SyS-T protocol
> support").
Why is this significant?
> diff --git a/drivers/hwtracing/stm/p_ost.c b/drivers/hwtracing/stm/p_ost.c
> new file mode 100644
> index 000000000000..2ca1a3fda57f
> --- /dev/null
> +++ b/drivers/hwtracing/stm/p_ost.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copied from drivers/hwtracing/stm.p-sys-t.c as of commit d69d5e83110f
> + * ("stm class: Add MIPI SyS-T protocol support").
Same as in the commit message.
[...]
> +#define OST_TOKEN_STARTSIMPLE (0x10)
> +#define OST_VERSION_MIPI1 (0x10 << 8)
> +#define OST_ENTITY_FTRACE (0x01 << 16)
> +#define OST_CONTROL_PROTOCOL (0x0 << 24)
These could use an explanation.
> +#define DATA_HEADER (OST_TOKEN_STARTSIMPLE | OST_VERSION_MIPI1 | \
> + OST_ENTITY_FTRACE | OST_CONTROL_PROTOCOL)
Does this mean that everything is ftrace? Because it's not.
> +
> +#define STM_MAKE_VERSION(ma, mi) ((ma << 8) | mi)
> +#define STM_HEADER_MAGIC (0x5953)
> +
> +static ssize_t notrace ost_write(struct stm_data *data,
> + struct stm_output *output, unsigned int chan,
> + const char *buf, size_t count)
> +{
> + unsigned int c = output->channel + chan;
> + unsigned int m = output->master;
> + const unsigned char nil = 0;
> + u32 header = DATA_HEADER;
> + u8 trc_hdr[24];
> + ssize_t sz;
> +
> + /*
> + * STP framing rules for OST frames:
> + * * the first packet of the OST frame is marked;
> + * * the last packet is a FLAG.
Which in your case is also timestamped.
> + */
> + /* Message layout: HEADER / DATA / TAIL */
> + /* HEADER */
> +
> + sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_MARKED,
> + 4, (u8 *)&header);
The /* HEADER */ comment applies to the above line, so it should
probably be directly before it.
> + if (sz <= 0)
> + return sz;
> + *(uint16_t *)(trc_hdr) = STM_MAKE_VERSION(0, 3);
> + *(uint16_t *)(trc_hdr + 2) = STM_HEADER_MAGIC;
> + *(uint32_t *)(trc_hdr + 4) = raw_smp_processor_id();
> + *(uint64_t *)(trc_hdr + 8) = sched_clock();
Why sched_clock()? It should, among other things, be called with
interrupts disabled, which is not the case here.
> + *(uint64_t *)(trc_hdr + 16) = task_tgid_nr(get_current());
Is there a reason why trc_hdr is not a struct?
Thanks,
--
Alex
Hi Alexande,
On 3/3/2023 2:05 AM, Alexander Shishkin wrote:
> Mao Jinlong <[email protected]> writes:
>
>> Add MIPI OST protocol support for stm to format the traces.
> Missing an explanation of what OST is, what it's used for, how it is
> different from the SyS-T and others.
I will updae the explanation in next version.
>
>> Framework copied from drivers/hwtracing/stm.p-sys-t.c as of
> You mean stm/p_sys-t.c. Also, it's not a framework, it's a driver.
The driver refers to code structure of p_sys-t driver. So, add this
comments after
internal review.
>
>> commit d69d5e83110f ("stm class: Add MIPI SyS-T protocol
>> support").
> Why is this significant?
>
>> diff --git a/drivers/hwtracing/stm/p_ost.c b/drivers/hwtracing/stm/p_ost.c
>> new file mode 100644
>> index 000000000000..2ca1a3fda57f
>> --- /dev/null
>> +++ b/drivers/hwtracing/stm/p_ost.c
>> @@ -0,0 +1,95 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copied from drivers/hwtracing/stm.p-sys-t.c as of commit d69d5e83110f
>> + * ("stm class: Add MIPI SyS-T protocol support").
> Same as in the commit message.
>
> [...]
>
>> +#define OST_TOKEN_STARTSIMPLE (0x10)
>> +#define OST_VERSION_MIPI1 (0x10 << 8)
>> +#define OST_ENTITY_FTRACE (0x01 << 16)
>> +#define OST_CONTROL_PROTOCOL (0x0 << 24)
> These could use an explanation.
I will add the explanation.
>> +#define DATA_HEADER (OST_TOKEN_STARTSIMPLE | OST_VERSION_MIPI1 | \
>> + OST_ENTITY_FTRACE | OST_CONTROL_PROTOCOL)
> Does this mean that everything is ftrace? Because it's not.
Only ftrace is supported in p_ost now. Other header type will be added
later.
>
>> +
>> +#define STM_MAKE_VERSION(ma, mi) ((ma << 8) | mi)
>> +#define STM_HEADER_MAGIC (0x5953)
>> +
>> +static ssize_t notrace ost_write(struct stm_data *data,
>> + struct stm_output *output, unsigned int chan,
>> + const char *buf, size_t count)
>> +{
>> + unsigned int c = output->channel + chan;
>> + unsigned int m = output->master;
>> + const unsigned char nil = 0;
>> + u32 header = DATA_HEADER;
>> + u8 trc_hdr[24];
>> + ssize_t sz;
>> +
>> + /*
>> + * STP framing rules for OST frames:
>> + * * the first packet of the OST frame is marked;
>> + * * the last packet is a FLAG.
> Which in your case is also timestamped.
I will add the comments.
>
>> + */
>> + /* Message layout: HEADER / DATA / TAIL */
>> + /* HEADER */
>> +
>> + sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_MARKED,
>> + 4, (u8 *)&header);
> The /* HEADER */ comment applies to the above line, so it should
> probably be directly before it.
Got it.
>
>> + if (sz <= 0)
>> + return sz;
>> + *(uint16_t *)(trc_hdr) = STM_MAKE_VERSION(0, 3);
>> + *(uint16_t *)(trc_hdr + 2) = STM_HEADER_MAGIC;
>> + *(uint32_t *)(trc_hdr + 4) = raw_smp_processor_id();
>> + *(uint64_t *)(trc_hdr + 8) = sched_clock();
> Why sched_clock()? It should, among other things, be called with
> interrupts disabled, which is not the case here.
I will check. If it is not necessary here, I will remove it.
>
>> + *(uint64_t *)(trc_hdr + 16) = task_tgid_nr(get_current());
> Is there a reason why trc_hdr is not a struct?
No particular reason here.
>
> Thanks,
> --
> Alex
On 3/7/2023 9:26 PM, Jinlong Mao wrote:
> Hi Alexander,
Sorry, correct the typo.
>
> On 3/3/2023 2:05 AM, Alexander Shishkin wrote:
>> Mao Jinlong <[email protected]> writes:
>>
>>> Add MIPI OST protocol support for stm to format the traces.
>> Missing an explanation of what OST is, what it's used for, how it is
>> different from the SyS-T and others.
> I will updae the explanation in next version.
>>
>>> Framework copied from drivers/hwtracing/stm.p-sys-t.c as of
>> You mean stm/p_sys-t.c. Also, it's not a framework, it's a driver.
>
> The driver refers to code structure of p_sys-t driver. So, add this
> comments after
> internal review.
>
>>
>>> commit d69d5e83110f ("stm class: Add MIPI SyS-T protocol
>>> support").
>> Why is this significant?
>>
>>> diff --git a/drivers/hwtracing/stm/p_ost.c
>>> b/drivers/hwtracing/stm/p_ost.c
>>> new file mode 100644
>>> index 000000000000..2ca1a3fda57f
>>> --- /dev/null
>>> +++ b/drivers/hwtracing/stm/p_ost.c
>>> @@ -0,0 +1,95 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copied from drivers/hwtracing/stm.p-sys-t.c as of commit
>>> d69d5e83110f
>>> + * ("stm class: Add MIPI SyS-T protocol support").
>> Same as in the commit message.
>>
>> [...]
>>
>>> +#define OST_TOKEN_STARTSIMPLE (0x10)
>>> +#define OST_VERSION_MIPI1 (0x10 << 8)
>>> +#define OST_ENTITY_FTRACE (0x01 << 16)
>>> +#define OST_CONTROL_PROTOCOL (0x0 << 24)
>> These could use an explanation.
> I will add the explanation.
>>> +#define DATA_HEADER (OST_TOKEN_STARTSIMPLE | OST_VERSION_MIPI1 | \
>>> + OST_ENTITY_FTRACE | OST_CONTROL_PROTOCOL)
>> Does this mean that everything is ftrace? Because it's not.
> Only ftrace is supported in p_ost now. Other header type will be added
> later.
>>
>>> +
>>> +#define STM_MAKE_VERSION(ma, mi) ((ma << 8) | mi)
>>> +#define STM_HEADER_MAGIC (0x5953)
>>> +
>>> +static ssize_t notrace ost_write(struct stm_data *data,
>>> + struct stm_output *output, unsigned int chan,
>>> + const char *buf, size_t count)
>>> +{
>>> + unsigned int c = output->channel + chan;
>>> + unsigned int m = output->master;
>>> + const unsigned char nil = 0;
>>> + u32 header = DATA_HEADER;
>>> + u8 trc_hdr[24];
>>> + ssize_t sz;
>>> +
>>> + /*
>>> + * STP framing rules for OST frames:
>>> + * * the first packet of the OST frame is marked;
>>> + * * the last packet is a FLAG.
>> Which in your case is also timestamped.
> I will add the comments.
>>
>>> + */
>>> + /* Message layout: HEADER / DATA / TAIL */
>>> + /* HEADER */
>>> +
>>> + sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_MARKED,
>>> + 4, (u8 *)&header);
>> The /* HEADER */ comment applies to the above line, so it should
>> probably be directly before it.
> Got it.
>>
>>> + if (sz <= 0)
>>> + return sz;
>>> + *(uint16_t *)(trc_hdr) = STM_MAKE_VERSION(0, 3);
>>> + *(uint16_t *)(trc_hdr + 2) = STM_HEADER_MAGIC;
>>> + *(uint32_t *)(trc_hdr + 4) = raw_smp_processor_id();
>>> + *(uint64_t *)(trc_hdr + 8) = sched_clock();
>> Why sched_clock()? It should, among other things, be called with
>> interrupts disabled, which is not the case here.
> I will check. If it is not necessary here, I will remove it.
>>
>>> + *(uint64_t *)(trc_hdr + 16) = task_tgid_nr(get_current());
>> Is there a reason why trc_hdr is not a struct?
> No particular reason here.
>>
>> Thanks,
>> --
>> Alex