The Trace Network On Chip (TNOC) is an integration hierarchy which is a
hardware component that integrates the functionalities of TPDA and
funnels. It collects trace from subsystems and transfers it to coresight
sink.
In addition to the generic TNOC mentioned above, there is also a special type
of TNOC called Interconnect TNOC. Unlike the generic TNOC, the Interconnect
TNOC doesn't need ATID. Its primary function is to connect the source of
subsystems to the Aggregator TNOC. Its driver is different from this patch and
will describe it and upstream its driver separately.
Signed-off-by: Yuanfang Zhang <quic_yuanfang(a)quicinc.com>
---
Changes in v5:
- update cover-letter to describe the Interconnect TNOC.
- Link to v4: https://lore.kernel.org/r/20250415-trace-noc-v4-0-979938fedfd8@quicinc.com
Changes in v4:
- Fix dt_binding warning.
- update mask of trace_noc amba_id.
- Modify driver comments.
- rename TRACE_NOC_SYN_VAL to TRACE_NOC_SYNC_INTERVAL.
- Link to v3: https://lore.kernel.org/r/20250411-trace-noc-v3-0-1f19ddf7699b@quicinc.com
Changes in v3:
- Remove unnecessary sysfs nodes.
- update commit messages.
- Use 'writel' instead of 'write_relaxed' when writing to the register for the last time.
- Add trace_id ops.
- Link to v2: https://lore.kernel.org/r/20250226-trace-noc-driver-v2-0-8afc6584afc5@quici…
Changes in v2:
- Modified the format of DT binging file.
- Fix compile warnings.
- Link to v1: https://lore.kernel.org/r/46643089-b88d-49dc-be05-7bf0bb21f847@quicinc.com
---
Yuanfang Zhang (2):
dt-bindings: arm: Add device Trace Network On Chip definition
coresight: add coresight Trace Network On Chip driver
.../bindings/arm/qcom,coresight-tnoc.yaml | 111 ++++++++++++
drivers/hwtracing/coresight/Kconfig | 13 ++
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/coresight-tnoc.c | 191 +++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tnoc.h | 34 ++++
5 files changed, 350 insertions(+)
---
base-commit: a2cc6ff5ec8f91bc463fd3b0c26b61166a07eb11
change-id: 20250403-trace-noc-f8286b30408e
Best regards,
--
Yuanfang Zhang <quic_yuanfang(a)quicinc.com>
On Mon, 31 Mar 2025 10:14:53 +0300, Andy Shevchenko wrote:
> The fwnode.h is not supposed to be used by the drivers as it
> has the definitions for the core parts for different device
> property provider implementations. Drop it.
>
> Since the code wants to use the pointer to the struct fwnode_handle
> the forward declaration is provided.
>
> [...]
Applied, thanks!
[1/1] coresight: cti: Replace inclusion by struct fwnode_handle forward declaration
https://git.kernel.org/coresight/c/aad548a9
Best regards,
--
Suzuki K Poulose <suzuki.poulose(a)arm.com>
On 5/7/25 23:43, Yabin Cui wrote:
> perf always allocates contiguous AUX pages based on aux_watermark.
> However, this contiguous allocation doesn't benefit all PMUs. For
> instance, ARM SPE and TRBE operate with virtual pages, and Coresight
> ETR allocates a separate buffer. For these PMUs, allocating contiguous
> AUX pages unnecessarily exacerbates memory fragmentation. This
> fragmentation can prevent their use on long-running devices.
>
> This patch modifies the perf driver to be memory-friendly by default,
> by allocating non-contiguous AUX pages. For PMUs requiring contiguous
> pages (Intel BTS and some Intel PT), the existing
> PERF_PMU_CAP_AUX_NO_SG capability can be used. For PMUs that don't
> require but can benefit from contiguous pages (some Intel PT), a new
> capability, PERF_PMU_CAP_AUX_PREFER_LARGE, is added to maintain their
> existing behavior.
>
> Signed-off-by: Yabin Cui <yabinc(a)google.com>
> ---
> Changes since v3:
> Add comments and a local variable to explain max_order value
> changes in rb_alloc_aux().
>
> Changes since v2:
> Let NO_SG imply PREFER_LARGE. So PMUs don't need to set both flags.
> Then the only place needing PREFER_LARGE is intel/pt.c.
>
> Changes since v1:
> In v1, default is preferring contiguous pages, and add a flag to
> allocate non-contiguous pages. In v2, default is allocating
> non-contiguous pages, and add a flag to prefer contiguous pages.
>
> v1 patchset:
> perf,coresight: Reduce fragmentation with non-contiguous AUX pages for
> cs_etm
>
> arch/x86/events/intel/pt.c | 2 ++
> include/linux/perf_event.h | 1 +
> kernel/events/ring_buffer.c | 33 ++++++++++++++++++++++++---------
> 3 files changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
> index fa37565f6418..25ead919fc48 100644
> --- a/arch/x86/events/intel/pt.c
> +++ b/arch/x86/events/intel/pt.c
> @@ -1863,6 +1863,8 @@ static __init int pt_init(void)
>
> if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries))
> pt_pmu.pmu.capabilities = PERF_PMU_CAP_AUX_NO_SG;
> + else
> + pt_pmu.pmu.capabilities = PERF_PMU_CAP_AUX_PREFER_LARGE;
>
> pt_pmu.pmu.capabilities |= PERF_PMU_CAP_EXCLUSIVE |
> PERF_PMU_CAP_ITRACE |
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 0069ba6866a4..56d77348c511 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -301,6 +301,7 @@ struct perf_event_pmu_context;
> #define PERF_PMU_CAP_AUX_OUTPUT 0x0080
> #define PERF_PMU_CAP_EXTENDED_HW_TYPE 0x0100
> #define PERF_PMU_CAP_AUX_PAUSE 0x0200
> +#define PERF_PMU_CAP_AUX_PREFER_LARGE 0x0400
>
> /**
> * pmu::scope
> diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
> index 5130b119d0ae..69c90ea1b79a 100644
> --- a/kernel/events/ring_buffer.c
> +++ b/kernel/events/ring_buffer.c
> @@ -679,7 +679,19 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
> {
> bool overwrite = !(flags & RING_BUFFER_WRITABLE);
> int node = (event->cpu == -1) ? -1 : cpu_to_node(event->cpu);
> - int ret = -ENOMEM, max_order;
> + /*
> + * True if the PMU needs a contiguous AUX buffer (CAP_AUX_NO_SG) or
> + * prefers large contiguous pages (CAP_AUX_PREFER_LARGE).
> + */
> + bool use_contiguous_pages = event->pmu->capabilities & (
> + PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_PREFER_LARGE);
> + /*
> + * Initialize max_order to 0 for page allocation. This allocates single
> + * pages to minimize memory fragmentation. This is overriden if
Small nit typo -- s/overriden/overridden ^^^^
> + * use_contiguous_pages is true.
> + */
> + int max_order = 0;
> + int ret = -ENOMEM;
>
> if (!has_aux(event))
> return -EOPNOTSUPP;
> @@ -689,8 +701,8 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
>
> if (!overwrite) {
> /*
> - * Watermark defaults to half the buffer, and so does the
> - * max_order, to aid PMU drivers in double buffering.
> + * Watermark defaults to half the buffer, to aid PMU drivers
> + * in double buffering.
> */
> if (!watermark)
> watermark = min_t(unsigned long,
> @@ -698,16 +710,19 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
> (unsigned long)nr_pages << (PAGE_SHIFT - 1));
>
> /*
> - * Use aux_watermark as the basis for chunking to
> - * help PMU drivers honor the watermark.
> + * If using contiguous pages, use aux_watermark as the basis
> + * for chunking to help PMU drivers honor the watermark.
> */
> - max_order = get_order(watermark);
> + if (use_contiguous_pages)
> + max_order = get_order(watermark);
> } else {
> /*
> - * We need to start with the max_order that fits in nr_pages,
> - * not the other way around, hence ilog2() and not get_order.
> + * If using contiguous pages, we need to start with the
> + * max_order that fits in nr_pages, not the other way around,
> + * hence ilog2() and not get_order.
> */
> - max_order = ilog2(nr_pages);
> + if (use_contiguous_pages)
> + max_order = ilog2(nr_pages);
> watermark = 0;
> }
>
Reviewed-by: Anshuman Khandual <anshuman.khandual(a)arm.com>
On 07/05/2025 7:13 pm, Yabin Cui wrote:
> perf always allocates contiguous AUX pages based on aux_watermark.
> However, this contiguous allocation doesn't benefit all PMUs. For
> instance, ARM SPE and TRBE operate with virtual pages, and Coresight
> ETR allocates a separate buffer. For these PMUs, allocating contiguous
> AUX pages unnecessarily exacerbates memory fragmentation. This
> fragmentation can prevent their use on long-running devices.
>
> This patch modifies the perf driver to be memory-friendly by default,
> by allocating non-contiguous AUX pages. For PMUs requiring contiguous
> pages (Intel BTS and some Intel PT), the existing
> PERF_PMU_CAP_AUX_NO_SG capability can be used. For PMUs that don't
> require but can benefit from contiguous pages (some Intel PT), a new
> capability, PERF_PMU_CAP_AUX_PREFER_LARGE, is added to maintain their
> existing behavior.
>
> Signed-off-by: Yabin Cui <yabinc(a)google.com>
> ---
> Changes since v3:
> Add comments and a local variable to explain max_order value
> changes in rb_alloc_aux().
>
> Changes since v2:
> Let NO_SG imply PREFER_LARGE. So PMUs don't need to set both flags.
> Then the only place needing PREFER_LARGE is intel/pt.c.
>
> Changes since v1:
> In v1, default is preferring contiguous pages, and add a flag to
> allocate non-contiguous pages. In v2, default is allocating
> non-contiguous pages, and add a flag to prefer contiguous pages.
>
> v1 patchset:
> perf,coresight: Reduce fragmentation with non-contiguous AUX pages for
> cs_etm
>
> arch/x86/events/intel/pt.c | 2 ++
> include/linux/perf_event.h | 1 +
> kernel/events/ring_buffer.c | 33 ++++++++++++++++++++++++---------
> 3 files changed, 27 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
> index fa37565f6418..25ead919fc48 100644
> --- a/arch/x86/events/intel/pt.c
> +++ b/arch/x86/events/intel/pt.c
> @@ -1863,6 +1863,8 @@ static __init int pt_init(void)
>
> if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries))
> pt_pmu.pmu.capabilities = PERF_PMU_CAP_AUX_NO_SG;
> + else
> + pt_pmu.pmu.capabilities = PERF_PMU_CAP_AUX_PREFER_LARGE;
>
> pt_pmu.pmu.capabilities |= PERF_PMU_CAP_EXCLUSIVE |
> PERF_PMU_CAP_ITRACE |
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 0069ba6866a4..56d77348c511 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -301,6 +301,7 @@ struct perf_event_pmu_context;
> #define PERF_PMU_CAP_AUX_OUTPUT 0x0080
> #define PERF_PMU_CAP_EXTENDED_HW_TYPE 0x0100
> #define PERF_PMU_CAP_AUX_PAUSE 0x0200
> +#define PERF_PMU_CAP_AUX_PREFER_LARGE 0x0400
>
> /**
> * pmu::scope
> diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
> index 5130b119d0ae..69c90ea1b79a 100644
> --- a/kernel/events/ring_buffer.c
> +++ b/kernel/events/ring_buffer.c
> @@ -679,7 +679,19 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
> {
> bool overwrite = !(flags & RING_BUFFER_WRITABLE);
> int node = (event->cpu == -1) ? -1 : cpu_to_node(event->cpu);
> - int ret = -ENOMEM, max_order;
> + /*
> + * True if the PMU needs a contiguous AUX buffer (CAP_AUX_NO_SG) or
> + * prefers large contiguous pages (CAP_AUX_PREFER_LARGE).
> + */
> + bool use_contiguous_pages = event->pmu->capabilities & (> +
PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_PREFER_LARGE);
Reviewed-by: James Clark <james.clark(a)linaro.org>
Minor nit: this comment is a bit verbose IMO, and it's only describing
what rather than why. But the other one is ok.
> + /*
> + * Initialize max_order to 0 for page allocation. This allocates single
> + * pages to minimize memory fragmentation. This is overriden if
> + * use_contiguous_pages is true.
> + */
> + int max_order = 0;
> + int ret = -ENOMEM;
>
> if (!has_aux(event))
> return -EOPNOTSUPP;
> @@ -689,8 +701,8 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
>
> if (!overwrite) {
> /*
> - * Watermark defaults to half the buffer, and so does the
> - * max_order, to aid PMU drivers in double buffering.
> + * Watermark defaults to half the buffer, to aid PMU drivers
> + * in double buffering.
> */
> if (!watermark)
> watermark = min_t(unsigned long,
> @@ -698,16 +710,19 @@ int rb_alloc_aux(struct perf_buffer *rb, struct perf_event *event,
> (unsigned long)nr_pages << (PAGE_SHIFT - 1));
>
> /*
> - * Use aux_watermark as the basis for chunking to
> - * help PMU drivers honor the watermark.
> + * If using contiguous pages, use aux_watermark as the basis
> + * for chunking to help PMU drivers honor the watermark.
> */
> - max_order = get_order(watermark);
> + if (use_contiguous_pages)
> + max_order = get_order(watermark);
> } else {
> /*
> - * We need to start with the max_order that fits in nr_pages,
> - * not the other way around, hence ilog2() and not get_order.
> + * If using contiguous pages, we need to start with the
> + * max_order that fits in nr_pages, not the other way around,
> + * hence ilog2() and not get_order.
> */
> - max_order = ilog2(nr_pages);
> + if (use_contiguous_pages)
> + max_order = ilog2(nr_pages);
> watermark = 0;
> }
>
The Trace Network On Chip (TNOC) is an integration hierarchy which is a
hardware component that integrates the functionalities of TPDA and
funnels. It collects trace form subsystems and transfers to coresight
sink.
Signed-off-by: Yuanfang Zhang <quic_yuanfang(a)quicinc.com>
---
Changes in v3:
- Remove unnecessary sysfs nodes.
- update commit messages.
- Use 'writel' instead of 'write_relaxed' when writing to the register for the last time.
- Add trace_id ops.
- Link to v2: https://lore.kernel.org/r/20250226-trace-noc-driver-v2-0-8afc6584afc5@quici…
Changes in v2:
- Modified the format of DT binging file.
- Fix compile warnings.
- Link to v1: https://lore.kernel.org/r/46643089-b88d-49dc-be05-7bf0bb21f847@quicinc.com
---
Yuanfang Zhang (2):
dt-bindings: arm: Add device Trace Network On Chip definition
coresight: add coresight Trace Network On Chip driver
.../bindings/arm/qcom,coresight-tnoc.yaml | 111 ++++++++++++
drivers/hwtracing/coresight/Kconfig | 13 ++
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/coresight-tnoc.c | 186 +++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tnoc.h | 34 ++++
5 files changed, 345 insertions(+)
---
base-commit: a2cc6ff5ec8f91bc463fd3b0c26b61166a07eb11
change-id: 20250403-trace-noc-f8286b30408e
Best regards,
--
Yuanfang Zhang <quic_yuanfang(a)quicinc.com>
This series fixes and improves clock usage in the Arm CoreSight drivers.
Based on the DT binding documents, the trace clock (atclk) is defined in
some CoreSight modules, but support is absent. In most cases, the issue
is hidden because the atclk clock is shared by multiple CoreSight
modules and the clock is enabled anyway by other drivers. The first
three patches address this issue.
The programming clock (pclk) management in CoreSight drivers does not
use the devm_XXX() variant APIs, the drivers needs to manually disable
and release clocks for errors and for normal module exit. However, the
drivers miss to disable clocks during module exit. The atclk may also
not be disabled in CoreSight drivers during module exit. By using devm
APIs, patches 04 and 05 fix clock disabling issues.
Another issue is pclk might be enabled twice in init phase - once by
AMBA bus driver, and again by CoreSight drivers.
This is fixed in patch 06.
Patches 07 to 09 refactor the clock related code. Patch 07 consolidats
the clock initialization into a central place. Patch 08 makes the
clock enabling sequence consistent. Patch 09 removes redundant
condition checks and adds error handling in runtime PM.
This series is verified on Arm64 Hikey960 platform.
Changes from v1:
- Moved the coresight_get_enable_clocks() function into CoreSight core
layer (James).
- Added comments for clock naming "apb_pclk" and "apb" (James).
- Re-ordered patches for easier understanding (Anshuman).
- Minor improvement for commit log in patch 01 (Anshuman).
Leo Yan (9):
coresight: tmc: Support atclk
coresight: catu: Support atclk
coresight: etm4x: Support atclk
coresight: Disable programming clock properly
coresight: Disable trace bus clock properly
coresight: Avoid enable programming clock duplicately
coresight: Consolidate clock enabling
coresight: Make clock sequence consistent
coresight: Refactor runtime PM
drivers/hwtracing/coresight/coresight-catu.c | 53 ++++++++++++++++-----------------
drivers/hwtracing/coresight/coresight-catu.h | 1 +
drivers/hwtracing/coresight/coresight-core.c | 45 ++++++++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-cpu-debug.c | 41 +++++++++-----------------
drivers/hwtracing/coresight/coresight-ctcu-core.c | 24 +++++----------
drivers/hwtracing/coresight/coresight-etb10.c | 18 ++++--------
drivers/hwtracing/coresight/coresight-etm3x-core.c | 17 ++++-------
drivers/hwtracing/coresight/coresight-etm4x-core.c | 32 ++++++++++----------
drivers/hwtracing/coresight/coresight-etm4x.h | 4 ++-
drivers/hwtracing/coresight/coresight-funnel.c | 66 +++++++++++++++---------------------------
drivers/hwtracing/coresight/coresight-replicator.c | 63 ++++++++++++++--------------------------
drivers/hwtracing/coresight/coresight-stm.c | 34 +++++++++-------------
drivers/hwtracing/coresight/coresight-tmc-core.c | 48 +++++++++++++++---------------
drivers/hwtracing/coresight/coresight-tmc.h | 2 ++
drivers/hwtracing/coresight/coresight-tpiu.c | 36 ++++++++++-------------
include/linux/coresight.h | 30 ++-----------------
16 files changed, 225 insertions(+), 289 deletions(-)
--
2.34.1
The Trace Network On Chip (TNOC) is an integration hierarchy which is a
hardware component that integrates the functionalities of TPDA and
funnels. It collects trace form subsystems and transfers to coresight
sink.
Signed-off-by: Yuanfang Zhang <quic_yuanfang(a)quicinc.com>
---
Changes in v4:
- Fix dt_binding warning.
- update mask of trace_noc amba_id.
- Modify driver comments.
- rename TRACE_NOC_SYN_VAL to TRACE_NOC_SYNC_INTERVAL.
- Link to v3: https://lore.kernel.org/r/20250411-trace-noc-v3-0-1f19ddf7699b@quicinc.com
Changes in v3:
- Remove unnecessary sysfs nodes.
- update commit messages.
- Use 'writel' instead of 'write_relaxed' when writing to the register for the last time.
- Add trace_id ops.
- Link to v2: https://lore.kernel.org/r/20250226-trace-noc-driver-v2-0-8afc6584afc5@quici…
Changes in v2:
- Modified the format of DT binging file.
- Fix compile warnings.
- Link to v1: https://lore.kernel.org/r/46643089-b88d-49dc-be05-7bf0bb21f847@quicinc.com
---
Yuanfang Zhang (2):
dt-bindings: arm: Add device Trace Network On Chip definition
coresight: add coresight Trace Network On Chip driver
.../bindings/arm/qcom,coresight-tnoc.yaml | 111 ++++++++++++
drivers/hwtracing/coresight/Kconfig | 13 ++
drivers/hwtracing/coresight/Makefile | 1 +
drivers/hwtracing/coresight/coresight-tnoc.c | 191 +++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tnoc.h | 34 ++++
5 files changed, 350 insertions(+)
---
base-commit: a2cc6ff5ec8f91bc463fd3b0c26b61166a07eb11
change-id: 20250403-trace-noc-f8286b30408e
Best regards,
--
Yuanfang Zhang <quic_yuanfang(a)quicinc.com>