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SubjectRe: [RFC 07/11] coresight: sink: Add TRBE driver
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Date
On 11/10/20 12:45 PM, Anshuman Khandual wrote:
> Trace Buffer Extension (TRBE) implements a trace buffer per CPU which is
> accessible via the system registers. The TRBE supports different addressing
> modes including CPU virtual address and buffer modes including the circular
> buffer mode. The TRBE buffer is addressed by a base pointer (TRBBASER_EL1),
> an write pointer (TRBPTR_EL1) and a limit pointer (TRBLIMITR_EL1). But the
> access to the trace buffer could be prohibited by a higher exception level
> (EL3 or EL2), indicated by TRBIDR_EL1.P. The TRBE can also generate a CPU
> private interrupt (PPI) on address translation errors and when the buffer
> is full. Overall implementation here is inspired from the Arm SPE driver.
>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> Documentation/trace/coresight/coresight-trbe.rst | 36 ++
> arch/arm64/include/asm/sysreg.h | 2 +
> drivers/hwtracing/coresight/Kconfig | 11 +
> drivers/hwtracing/coresight/Makefile | 1 +
> drivers/hwtracing/coresight/coresight-trbe.c | 766 +++++++++++++++++++++++
> drivers/hwtracing/coresight/coresight-trbe.h | 525 ++++++++++++++++
> 6 files changed, 1341 insertions(+)
> create mode 100644 Documentation/trace/coresight/coresight-trbe.rst
> create mode 100644 drivers/hwtracing/coresight/coresight-trbe.c
> create mode 100644 drivers/hwtracing/coresight/coresight-trbe.h
>
> diff --git a/Documentation/trace/coresight/coresight-trbe.rst b/Documentation/trace/coresight/coresight-trbe.rst
> new file mode 100644
> index 0000000..4320a8b
> --- /dev/null
> +++ b/Documentation/trace/coresight/coresight-trbe.rst
> @@ -0,0 +1,36 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +==============================
> +Trace Buffer Extension (TRBE).
> +==============================
> +
> + :Author: Anshuman Khandual <anshuman.khandual@arm.com>
> + :Date: November 2020
> +
> +Hardware Description
> +--------------------
> +
> +Trace Buffer Extension (TRBE) is a percpu hardware which captures in system
> +memory, CPU traces generated from a corresponding percpu tracing unit. This
> +gets plugged in as a coresight sink device because the corresponding trace
> +genarators (ETE), are plugged in as source device.
> +
> +Sysfs files and directories
> +---------------------------
> +
> +The TRBE devices appear on the existing coresight bus alongside the other
> +coresight devices::
> +
> + >$ ls /sys/bus/coresight/devices
> + trbe0 trbe1 trbe2 trbe3
> +
> +The ``trbe<N>`` named TRBEs are associated with a CPU.::
> +
> + >$ ls /sys/bus/coresight/devices/trbe0/
> + irq align dbm
> +
> +*Key file items are:-*
> + * ``irq``: TRBE maintenance interrupt number
> + * ``align``: TRBE write pointer alignment
> + * ``dbm``: TRBE updates memory with access and dirty flags
> +
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index 14cb156..61136f6 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -97,6 +97,7 @@
> #define SET_PSTATE_UAO(x) __emit_inst(0xd500401f | PSTATE_UAO | ((!!x) << PSTATE_Imm_shift))
> #define SET_PSTATE_SSBS(x) __emit_inst(0xd500401f | PSTATE_SSBS | ((!!x) << PSTATE_Imm_shift))
> #define SET_PSTATE_TCO(x) __emit_inst(0xd500401f | PSTATE_TCO | ((!!x) << PSTATE_Imm_shift))
> +#define TSB_CSYNC __emit_inst(0xd503225f)
>
> #define __SYS_BARRIER_INSN(CRm, op2, Rt) \
> __emit_inst(0xd5000000 | sys_insn(0, 3, 3, (CRm), (op2)) | ((Rt) & 0x1f))
> @@ -865,6 +866,7 @@
> #define ID_AA64MMFR2_CNP_SHIFT 0
>
> /* id_aa64dfr0 */
> +#define ID_AA64DFR0_TRBE_SHIFT 44
> #define ID_AA64DFR0_TRACE_FILT_SHIFT 40
> #define ID_AA64DFR0_DOUBLELOCK_SHIFT 36
> #define ID_AA64DFR0_PMSVER_SHIFT 32
> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> index c119824..0f5e101 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -156,6 +156,17 @@ config CORESIGHT_CTI
> To compile this driver as a module, choose M here: the
> module will be called coresight-cti.
>
> +config CORESIGHT_TRBE
> + bool "Trace Buffer Extension (TRBE) driver"
> + depends on ARM64
> + help
> + This driver provides support for percpu Trace Buffer Extension (TRBE).
> + TRBE always needs to be used along with it's corresponding percpu ETE
> + component. ETE generates trace data which is then captured with TRBE.
> + Unlike traditional sink devices, TRBE is a CPU feature accessible via
> + system registers. But it's explicit dependency with trace unit (ETE)
> + requires it to be plugged in as a coresight sink device.
> +
> config CORESIGHT_CTI_INTEGRATION_REGS
> bool "Access CTI CoreSight Integration Registers"
> depends on CORESIGHT_CTI
> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> index f20e357..d608165 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -21,5 +21,6 @@ obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
> obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
> obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
> obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o
> +obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o
> coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \
> coresight-cti-sysfs.o
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> new file mode 100644
> index 0000000..48a8ec3
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -0,0 +1,766 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * This driver enables Trace Buffer Extension (TRBE) as a per-cpu coresight
> + * sink device could then pair with an appropriate per-cpu coresight source
> + * device (ETE) thus generating required trace data. Trace can be enabled
> + * via the perf framework.
> + *
> + * Copyright (C) 2020 ARM Ltd.
> + *
> + * Author: Anshuman Khandual <anshuman.khandual@arm.com>
> + */
> +#define DRVNAME "arm_trbe"
> +
> +#define pr_fmt(fmt) DRVNAME ": " fmt
> +
> +#include "coresight-trbe.h"
> +
> +#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
> +
> +#define ETE_IGNORE_PACKET 0x70

Add a comment here, on what this means to the decoder.

> +
> +static const char trbe_name[] = "trbe";

Why not

#define DEVNAME "trbe"


> +
> +enum trbe_fault_action {
> + TRBE_FAULT_ACT_WRAP,
> + TRBE_FAULT_ACT_SPURIOUS,
> + TRBE_FAULT_ACT_FATAL,
> +};
> +
> +struct trbe_perf {

Please rename this to trbe_buf. This will be used for sysfs mode as well.

> + unsigned long trbe_base;
> + unsigned long trbe_limit;
> + unsigned long trbe_write;
> + pid_t pid;

Why do we need this ? This seems unused and moreover, there cannot
be multiple tracers into TRBE. So, we don't need to share the sink
unlike the traditional ones.

> + int nr_pages;
> + void **pages;
> + bool snapshot;
> + struct trbe_cpudata *cpudata;
> +};
> +
> +struct trbe_cpudata {
> + struct coresight_device *csdev;
> + bool trbe_dbm;

Why do we need this ?

> + u64 trbe_align;
> + int cpu;
> + enum cs_mode mode;
> + struct trbe_perf *perf;
> + struct trbe_drvdata *drvdata;
> +};
> +
> +struct trbe_drvdata {
> + struct trbe_cpudata __percpu *cpudata;
> + struct perf_output_handle __percpu *handle;

Shouldn't this be :

struct perf_output_handle __percpu **handle ?

as we get a handle from the etm-perf and is not controlled by
the TRBE ?

> + struct hlist_node hotplug_node;
> + int irq;
> + cpumask_t supported_cpus;
> + enum cpuhp_state trbe_online;
> + struct platform_device *pdev;
> + struct clk *atclk;

We don't have any clocks for the TRBE instance. Please remove.

> +};
> +
> +static int trbe_alloc_node(struct perf_event *event)
> +{
> + if (event->cpu == -1)
> + return NUMA_NO_NODE;
> + return cpu_to_node(event->cpu);
> +}
> +
> +static void trbe_disable_and_drain_local(void)
> +{
> + write_sysreg_s(0, SYS_TRBLIMITR_EL1);
> + isb();
> + dsb(nsh);
> + asm(TSB_CSYNC);
> +}
> +
> +static void trbe_reset_local(void)
> +{
> + trbe_disable_and_drain_local();
> + write_sysreg_s(0, SYS_TRBPTR_EL1);
> + isb();
> +
> + write_sysreg_s(0, SYS_TRBBASER_EL1);
> + isb();
> +
> + write_sysreg_s(0, SYS_TRBSR_EL1);
> + isb();
> +}
> +
> +static void trbe_pad_buf(struct perf_output_handle *handle, int len)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + u64 head = PERF_IDX2OFF(handle->head, perf);
> +
> + memset((void *) perf->trbe_base + head, ETE_IGNORE_PACKET, len);
> + if (!perf->snapshot)
> + perf_aux_output_skip(handle, len);
> +}
> +
> +static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + u64 head = PERF_IDX2OFF(handle->head, perf);
> + u64 limit = perf->nr_pages * PAGE_SIZE;
> +

So we are using half of the buffer for snapshot mode to avoid a case where the
analyzer is unable to decode the trace in case of an overflow.

> + if (head < limit >> 1)
> + limit >>= 1;

Also this needs to be thought out. We may not need this restriction. The trace decoder
will be able to walk forward and then find a synchronization packet and then continue
the tracing from there. So, we could use the entire buffer for TRBE.


> +
> + return limit;
> +}
> +
> +static unsigned long trbe_normal_offset(struct perf_output_handle *handle)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + struct trbe_cpudata *cpudata = perf->cpudata;
> + const u64 bufsize = perf->nr_pages * PAGE_SIZE;
> + u64 limit = bufsize;
> + u64 head, tail, wakeup;
> +

Commentary please.

> + head = PERF_IDX2OFF(handle->head, perf);
> + if (!IS_ALIGNED(head, cpudata->trbe_align)) {
> + unsigned long delta = roundup(head, cpudata->trbe_align) - head;
> +
> + delta = min(delta, handle->size);
> + trbe_pad_buf(handle, delta);
> + head = PERF_IDX2OFF(handle->head, perf);
> + }
> +
> + if (!handle->size) {
> + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> + return 0;
> + }
> +
> + tail = PERF_IDX2OFF(handle->head + handle->size, perf);
> + wakeup = PERF_IDX2OFF(handle->wakeup, perf);
> +

> + if (head < tail)

comment

> + limit = round_down(tail, PAGE_SIZE);
> +
> + if (handle->wakeup < (handle->head + handle->size) && head <= wakeup)
> + limit = min(limit, round_up(wakeup, PAGE_SIZE));

comment. Also do we need an alignement to PAGE_SIZE ?

> +
> + if (limit > head)
> + return limit;
> +
> + trbe_pad_buf(handle, handle->size);
> + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> + return 0;
> +}
> +
> +static unsigned long get_trbe_limit(struct perf_output_handle *handle)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + unsigned long offset;
> +
> + if (perf->snapshot)
> + offset = trbe_snapshot_offset(handle);
> + else
> + offset = trbe_normal_offset(handle);
> + return perf->trbe_base + offset;
> +}
> +
> +static void trbe_enable_hw(struct trbe_perf *perf)
> +{
> + WARN_ON(perf->trbe_write < perf->trbe_base);
> + WARN_ON(perf->trbe_write >= perf->trbe_limit);
> + set_trbe_disabled();
> + clr_trbe_irq();
> + clr_trbe_wrap();
> + clr_trbe_abort();
> + clr_trbe_ec();
> + clr_trbe_bsc();
> + clr_trbe_fsc();

Please merge all of these field updates to single register update
unless mandated by the architecture.

> + set_trbe_virtual_mode();
> + set_trbe_fill_mode(TRBE_FILL_STOP);
> + set_trbe_trig_mode(TRBE_TRIGGER_IGNORE);

Same here ^^

> + isb();
> + set_trbe_base_pointer(perf->trbe_base);
> + set_trbe_limit_pointer(perf->trbe_limit);
> + set_trbe_write_pointer(perf->trbe_write);
> + isb();
> + dsb(ishst);
> + flush_tlb_all();

Why is this needed ?

> + set_trbe_running();
> + set_trbe_enabled();
> + asm(TSB_CSYNC);
> +}
> +
> +static void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
> + struct perf_event *event, void **pages,
> + int nr_pages, bool snapshot)
> +{
> + struct trbe_perf *perf;
> + struct page **pglist;
> + int i;
> +
> + if ((nr_pages < 2) || (snapshot && (nr_pages & 1)))

We may be able to remove the restriction on snapshot mode, see my comment
above.

> + return NULL;
> +
> + perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, trbe_alloc_node(event));
> + if (IS_ERR(perf))
> + return ERR_PTR(-ENOMEM);
> +
> + pglist = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL);
> + if (IS_ERR(pglist)) {
> + kfree(perf);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + for (i = 0; i < nr_pages; i++)
> + pglist[i] = virt_to_page(pages[i]);
> +
> + perf->trbe_base = (unsigned long) vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
> + if (IS_ERR((void *) perf->trbe_base)) {
> + kfree(pglist);
> + kfree(perf);
> + return ERR_PTR(perf->trbe_base);
> + }
> + perf->trbe_limit = perf->trbe_base + nr_pages * PAGE_SIZE;
> + perf->trbe_write = perf->trbe_base;
> + perf->pid = task_pid_nr(event->owner);
> + perf->snapshot = snapshot;
> + perf->nr_pages = nr_pages;
> + perf->pages = pages;
> + kfree(pglist);
> + return perf;
> +}
> +
> +void arm_trbe_free_buffer(void *config)
> +{
> + struct trbe_perf *perf = config;
> +
> + vunmap((void *) perf->trbe_base);
> + kfree(perf);
> +}
> +
> +static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev,
> + struct perf_output_handle *handle,
> + void *config)
> +{
> + struct trbe_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> + struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev);
> + struct trbe_perf *perf = config;
> + unsigned long size, offset;
> +
> + WARN_ON(perf->cpudata != cpudata);
> + WARN_ON(cpudata->cpu != smp_processor_id());
> + WARN_ON(cpudata->mode != CS_MODE_PERF);
> + WARN_ON(cpudata->drvdata != drvdata);
> +
> + offset = get_trbe_write_pointer() - get_trbe_base_pointer();
> + size = offset - PERF_IDX2OFF(handle->head, perf);
> + if (perf->snapshot)
> + handle->head += size;
> + return size;
> +}
> +
> +static int arm_trbe_enable(struct coresight_device *csdev, u32 mode, void *data)
> +{
> + struct trbe_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> + struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev);
> + struct perf_output_handle *handle = data;
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> +
> + WARN_ON(cpudata->cpu != smp_processor_id());
> + WARN_ON(mode != CS_MODE_PERF);

Why WARN_ON ? Simply return -EINVAL ? Also you need a check to make sure
the mode is DISABLED (when you get to sysfs mode).

> + WARN_ON(cpudata->drvdata != drvdata);
> +
> + *this_cpu_ptr(drvdata->handle) = *handle;

That is wrong. Storing a local copy of a global perf generic structure
is calling for trouble, assuming that the global structure doesn't change
beneath us. Please store handle ptr.

> + cpudata->perf = perf;
> + cpudata->mode = mode;
> + perf->cpudata = cpudata;
> + perf->trbe_write = perf->trbe_base + PERF_IDX2OFF(handle->head, perf);
> + perf->trbe_limit = get_trbe_limit(handle);
> + if (perf->trbe_limit == perf->trbe_base) {
> + trbe_disable_and_drain_local();
> + return 0;
> + }
> + trbe_enable_hw(perf);
> + return 0;
> +}
> +
> +static int arm_trbe_disable(struct coresight_device *csdev)
> +{
> + struct trbe_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> + struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev);
> + struct trbe_perf *perf = cpudata->perf;
> +
> + WARN_ON(perf->cpudata != cpudata);
> + WARN_ON(cpudata->cpu != smp_processor_id());
> + WARN_ON(cpudata->mode != CS_MODE_PERF);
> + WARN_ON(cpudata->drvdata != drvdata);
> +
> + trbe_disable_and_drain_local();
> + perf->cpudata = NULL;
> + cpudata->perf = NULL;
> + cpudata->mode = CS_MODE_DISABLED;
> + return 0;
> +}
> +
> +static void trbe_handle_fatal(struct perf_output_handle *handle)
> +{
> + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> + perf_aux_output_end(handle, 0);
> + trbe_disable_and_drain_local();
> +}
> +
> +static void trbe_handle_spurious(struct perf_output_handle *handle)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> +
> + perf->trbe_write = perf->trbe_base + PERF_IDX2OFF(handle->head, perf);
> + perf->trbe_limit = get_trbe_limit(handle);
> + if (perf->trbe_limit == perf->trbe_base) {
> + trbe_disable_and_drain_local();
> + return;
> + }
> + trbe_enable_hw(perf);
> +}
> +
> +static void trbe_handle_overflow(struct perf_output_handle *handle)
> +{
> + struct perf_event *event = handle->event;
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + unsigned long offset, size;
> + struct etm_event_data *event_data;
> +
> + offset = get_trbe_limit_pointer() - get_trbe_base_pointer();
> + size = offset - PERF_IDX2OFF(handle->head, perf);
> + if (perf->snapshot)
> + handle->head = offset;

Is this correct ? Or was this supposed to mean :
handle->head += offset;


> + perf_aux_output_end(handle, size);
> +
> + event_data = perf_aux_output_begin(handle, event);
> + if (!event_data) {
> + event->hw.state |= PERF_HES_STOPPED;
> + trbe_disable_and_drain_local();
> + return;
> + }
> + perf->trbe_write = perf->trbe_base;
> + perf->trbe_limit = get_trbe_limit(handle);
> + if (perf->trbe_limit == perf->trbe_base) {
> + trbe_disable_and_drain_local();
> + return;
> + }
> + *this_cpu_ptr(perf->cpudata->drvdata->handle) = *handle;
> + trbe_enable_hw(perf);
> +}
> +
> +static bool is_perf_trbe(struct perf_output_handle *handle)
> +{
> + struct trbe_perf *perf = etm_perf_sink_config(handle);
> + struct trbe_cpudata *cpudata = perf->cpudata;
> + struct trbe_drvdata *drvdata = cpudata->drvdata;

Can you trust the cpudata ptr here as we are still verifying
if this was legitimate ?

> + int cpu = smp_processor_id();
> +
> + WARN_ON(perf->trbe_base != get_trbe_base_pointer());
> + WARN_ON(perf->trbe_limit != get_trbe_limit_pointer());
> +
> + if (cpudata->mode != CS_MODE_PERF)
> + return false;
> +
> + if (cpudata->cpu != cpu)
> + return false;
> +
> + if (!cpumask_test_cpu(cpu, &drvdata->supported_cpus))
> + return false;
> +
> + return true;
> +}
> +
> +static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *handle)
> +{
> + enum trbe_ec ec = get_trbe_ec();
> + enum trbe_bsc bsc = get_trbe_bsc();
> +
> + WARN_ON(is_trbe_running());
> + asm(TSB_CSYNC);
> + dsb(nsh);
> + isb();
> +
> + if (is_trbe_trg() || is_trbe_abort())
> + return TRBE_FAULT_ACT_FATAL;
> +
> + if ((ec == TRBE_EC_STAGE1_ABORT) || (ec == TRBE_EC_STAGE2_ABORT))
> + return TRBE_FAULT_ACT_FATAL;
> +
> + if (is_trbe_wrap() && (ec == TRBE_EC_OTHERS) && (bsc == TRBE_BSC_FILLED)) {
> + if (get_trbe_write_pointer() == get_trbe_base_pointer())
> + return TRBE_FAULT_ACT_WRAP;
> + }
> + return TRBE_FAULT_ACT_SPURIOUS;
> +}
> +
> +static irqreturn_t arm_trbe_irq_handler(int irq, void *dev)
> +{
> + struct perf_output_handle *handle = dev;
> + enum trbe_fault_action act;
> +
> + WARN_ON(!is_trbe_irq());
> + clr_trbe_irq();
> +
> + if (!perf_get_aux(handle))
> + return IRQ_NONE;
> +
> + if (!is_perf_trbe(handle))
> + return IRQ_NONE;
> +
> + irq_work_run();
> +
> + act = trbe_get_fault_act(handle);
> + switch (act) {
> + case TRBE_FAULT_ACT_WRAP:
> + trbe_handle_overflow(handle);
> + break;
> + case TRBE_FAULT_ACT_SPURIOUS:
> + trbe_handle_spurious(handle);
> + break;
> + case TRBE_FAULT_ACT_FATAL:
> + trbe_handle_fatal(handle);
> + break;
> + }
> + return IRQ_HANDLED;
> +}
> +


> +static void arm_trbe_probe_coresight_cpu(void *info)
> +{
> + struct trbe_cpudata *cpudata = info;
> + struct device *dev = &cpudata->drvdata->pdev->dev;
> + struct coresight_desc desc = { 0 };
> +
> + if (WARN_ON(!cpudata))
> + goto cpu_clear;
> +
> + if (!is_trbe_available()) {
> + pr_err("TRBE is not implemented on cpu %d\n", cpudata->cpu);
> + goto cpu_clear;
> + }
> +
> + if (!is_trbe_programmable()) {
> + pr_err("TRBE is owned in higher exception level on cpu %d\n", cpudata->cpu);
> + goto cpu_clear;
> + }
> + desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", trbe_name, smp_processor_id());
> + if (IS_ERR(desc.name))
> + goto cpu_clear;
> +
> + desc.type = CORESIGHT_DEV_TYPE_SINK;
> + desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM;

May be should add a new subtype to make this higher priority than the normal ETR.
Something like :

CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM

> + desc.ops = &arm_trbe_cs_ops;
> + desc.pdata = dev_get_platdata(dev);
> + desc.groups = arm_trbe_groups;
> + desc.dev = dev;
> + cpudata->csdev = coresight_register(&desc);
> + if (IS_ERR(cpudata->csdev))
> + goto cpu_clear;
> +
> + dev_set_drvdata(&cpudata->csdev->dev, cpudata);
> + cpudata->trbe_dbm = get_trbe_flag_update();
> + cpudata->trbe_align = 1ULL << get_trbe_address_align();
> + if (cpudata->trbe_align > SZ_2K) {
> + pr_err("Unsupported alignment on cpu %d\n", cpudata->cpu);
> + goto cpu_clear;
> + }
> + return;
> +cpu_clear:
> + cpumask_clear_cpu(cpudata->cpu, &cpudata->drvdata->supported_cpus);
> +}
> +
> +static int arm_trbe_probe_coresight(struct trbe_drvdata *drvdata)
> +{
> + struct trbe_cpudata *cpudata;
> + int cpu;
> +
> + drvdata->cpudata = alloc_percpu(typeof(*drvdata->cpudata));
> + if (IS_ERR(drvdata->cpudata))
> + return PTR_ERR(drvdata->cpudata);
> +
> + for_each_cpu(cpu, &drvdata->supported_cpus) {
> + cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
> + cpudata->cpu = cpu;
> + cpudata->drvdata = drvdata;
> + smp_call_function_single(cpu, arm_trbe_probe_coresight_cpu, cpudata, 1);

We could batch it and run it on all CPUs at the same time ? Also it would be better to
leave the per_cpu area filled by the CPU itself, to avoid racing.


> + }
> + return 0;
> +}
> +
> +static void arm_trbe_remove_coresight_cpu(void *info)
> +{
> + struct trbe_drvdata *drvdata = info;
> +
> + disable_percpu_irq(drvdata->irq);
> +}
> +
> +static int arm_trbe_remove_coresight(struct trbe_drvdata *drvdata)
> +{
> + struct trbe_cpudata *cpudata;
> + int cpu;
> +
> + for_each_cpu(cpu, &drvdata->supported_cpus) {
> + smp_call_function_single(cpu, arm_trbe_remove_coresight_cpu, drvdata, 1);
> + cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
> + if (cpudata->csdev) {
> + coresight_unregister(cpudata->csdev);
> + cpudata->drvdata = NULL;
> + cpudata->csdev = NULL;
> + }

Please leave this to the CPU to do the part.

> + }
> + free_percpu(drvdata->cpudata);
> + return 0;
> +}
> +
> +static int arm_trbe_cpu_startup(unsigned int cpu, struct hlist_node *node)
> +{
> + struct trbe_drvdata *drvdata = hlist_entry_safe(node, struct trbe_drvdata, hotplug_node);
> + struct trbe_cpudata *cpudata;
> +
> + if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) {
> + cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
> + if (!cpudata->csdev) {
> + cpudata->drvdata = drvdata;
> + smp_call_function_single(cpu, arm_trbe_probe_coresight_cpu, cpudata, 1);

Why do we need smp_call here ? We are already on the CPU.

> + }
> + trbe_reset_local();
> + enable_percpu_irq(drvdata->irq, IRQ_TYPE_NONE);
> + }
> + return 0;
> +}
> +
> +static int arm_trbe_cpu_teardown(unsigned int cpu, struct hlist_node *node)
> +{
> + struct trbe_drvdata *drvdata = hlist_entry_safe(node, struct trbe_drvdata, hotplug_node);
> + struct trbe_cpudata *cpudata;
> +
> + if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) {
> + cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
> + if (cpudata->csdev) {
> + coresight_unregister(cpudata->csdev);
> + cpudata->drvdata = NULL;
> + cpudata->csdev = NULL;
> + }
> + disable_percpu_irq(drvdata->irq);
> + trbe_reset_local();
> + }
> + return 0;
> +}
> +
> +static int arm_trbe_probe_cpuhp(struct trbe_drvdata *drvdata)
> +{
> + enum cpuhp_state trbe_online;
> +
> + trbe_online = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRVNAME,
> + arm_trbe_cpu_startup, arm_trbe_cpu_teardown);
> + if (trbe_online < 0)
> + return -EINVAL;
> +
> + if (cpuhp_state_add_instance(trbe_online, &drvdata->hotplug_node))
> + return -EINVAL;
> +
> + drvdata->trbe_online = trbe_online;
> + return 0;
> +}
> +
> +static void arm_trbe_remove_cpuhp(struct trbe_drvdata *drvdata)
> +{
> + cpuhp_remove_multi_state(drvdata->trbe_online);
> +}
> +
> +static int arm_trbe_probe_irq(struct platform_device *pdev,
> + struct trbe_drvdata *drvdata)
> +{
> + drvdata->irq = platform_get_irq(pdev, 0);
> + if (!drvdata->irq) {
> + pr_err("IRQ not found for the platform device\n");
> + return -ENXIO;
> + }
> +
> + if (!irq_is_percpu(drvdata->irq)) {
> + pr_err("IRQ is not a PPI\n");
> + return -EINVAL;
> + }
> +
> + if (irq_get_percpu_devid_partition(drvdata->irq, &drvdata->supported_cpus))
> + return -EINVAL;
> +
> + drvdata->handle = alloc_percpu(typeof(*drvdata->handle));
> + if (!drvdata->handle)
> + return -ENOMEM;
> +
> + if (request_percpu_irq(drvdata->irq, arm_trbe_irq_handler, DRVNAME, drvdata->handle)) {
> + free_percpu(drvdata->handle);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static void arm_trbe_remove_irq(struct trbe_drvdata *drvdata)
> +{
> + free_percpu_irq(drvdata->irq, drvdata->handle);
> + free_percpu(drvdata->handle);
> +}
> +
> +static int arm_trbe_device_probe(struct platform_device *pdev)
> +{
> + struct coresight_platform_data *pdata;
> + struct trbe_drvdata *drvdata;
> + struct device *dev = &pdev->dev;
> + int ret;
> +
> + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> + if (IS_ERR(drvdata))
> + return -ENOMEM;
> +
> + pdata = coresight_get_platform_data(dev);
> + if (IS_ERR(pdata)) {
> + kfree(drvdata);
> + return -ENOMEM;
> + }


> +
> + drvdata->atclk = devm_clk_get(dev, "atclk");
> + if (!IS_ERR(drvdata->atclk)) {
> + ret = clk_prepare_enable(drvdata->atclk);
> + if (ret)
> + return ret;
> + }

Please drop the clocks, we don't have any

> + dev_set_drvdata(dev, drvdata);
> + dev->platform_data = pdata;
> + drvdata->pdev = pdev;
> + ret = arm_trbe_probe_irq(pdev, drvdata);
> + if (ret)
> + goto irq_failed;
> +
> + ret = arm_trbe_probe_coresight(drvdata);
> + if (ret)
> + goto probe_failed;
> +
> + ret = arm_trbe_probe_cpuhp(drvdata);
> + if (ret)
> + goto cpuhp_failed;
> +
> + return 0;
> +cpuhp_failed:
> + arm_trbe_remove_coresight(drvdata);
> +probe_failed:
> + arm_trbe_remove_irq(drvdata);
> +irq_failed:
> + kfree(pdata);
> + kfree(drvdata);
> + return ret;
> +}
> +
> +static int arm_trbe_device_remove(struct platform_device *pdev)
> +{
> + struct coresight_platform_data *pdata = dev_get_platdata(&pdev->dev);
> + struct trbe_drvdata *drvdata = platform_get_drvdata(pdev);
> +
> + arm_trbe_remove_coresight(drvdata);
> + arm_trbe_remove_cpuhp(drvdata);
> + arm_trbe_remove_irq(drvdata);
> + kfree(pdata);
> + kfree(drvdata);
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int arm_trbe_runtime_suspend(struct device *dev)
> +{
> + struct trbe_drvdata *drvdata = dev_get_drvdata(dev);
> +
> + if (drvdata && !IS_ERR(drvdata->atclk))
> + clk_disable_unprepare(drvdata->atclk);
> +

Remove. We may need to save/restore the TRBE ptrs, depending on the
TRBE.

> + return 0;
> +}
> +
> +static int arm_trbe_runtime_resume(struct device *dev)
> +{
> + struct trbe_drvdata *drvdata = dev_get_drvdata(dev);
> +
> + if (drvdata && !IS_ERR(drvdata->atclk))
> + clk_prepare_enable(drvdata->atclk);

Remove. See above.

> +
> + return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops arm_trbe_dev_pm_ops = {
> + SET_RUNTIME_PM_OPS(arm_trbe_runtime_suspend, arm_trbe_runtime_resume, NULL)
> +};
> +
> +static const struct of_device_id arm_trbe_of_match[] = {
> + { .compatible = "arm,arm-trbe", .data = (void *)1 },
> + {},
> +};

I think it is better to call this, we have too many acronyms ;-)

"arm,trace-buffer-extension"

> +MODULE_DEVICE_TABLE(of, arm_trbe_of_match);

> +
> +static const struct platform_device_id arm_trbe_match[] = {
> + { "arm,trbe", 0},
> + { }
> +};
> +MODULE_DEVICE_TABLE(platform, arm_trbe_match);

Please remove. The ACPI part can be added when we get to it.

> +
> +static struct platform_driver arm_trbe_driver = {
> + .id_table = arm_trbe_match,
> + .driver = {
> + .name = DRVNAME,
> + .of_match_table = of_match_ptr(arm_trbe_of_match),
> + .pm = &arm_trbe_dev_pm_ops,
> + .suppress_bind_attrs = true,
> + },
> + .probe = arm_trbe_device_probe,
> + .remove = arm_trbe_device_remove,
> +};
> +builtin_platform_driver(arm_trbe_driver)

Please make this modular.


> diff --git a/drivers/hwtracing/coresight/coresight-trbe.h b/drivers/hwtracing/coresight/coresight-trbe.h
> new file mode 100644
> index 0000000..82ffbfc
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-trbe.h
> @@ -0,0 +1,525 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * This contains all required hardware related helper functions for
> + * Trace Buffer Extension (TRBE) driver in the coresight framework.
> + *
> + * Copyright (C) 2020 ARM Ltd.
> + *
> + * Author: Anshuman Khandual <anshuman.khandual@arm.com>
> + */
> +#include <linux/coresight.h>
> +#include <linux/device.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/smp.h>
> +
> +#include "coresight-etm-perf.h"
> +
> +static inline bool is_trbe_available(void)
> +{
> + u64 aa64dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1);
> + int trbe = cpuid_feature_extract_unsigned_field(aa64dfr0, ID_AA64DFR0_TRBE_SHIFT);
> +
> + return trbe >= 0b0001;
> +}
> +
> +static inline bool is_ete_available(void)
> +{
> + u64 aa64dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1);
> + int tracever = cpuid_feature_extract_unsigned_field(aa64dfr0, ID_AA64DFR0_TRACEVER_SHIFT);
> +
> + return (tracever != 0b0000);

Why is this needed ?

> +}
> +
> +static inline bool is_trbe_enabled(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + return trblimitr & TRBLIMITR_ENABLE;
> +}
> +
> +enum trbe_ec {
> + TRBE_EC_OTHERS = 0,
> + TRBE_EC_STAGE1_ABORT = 36,
> + TRBE_EC_STAGE2_ABORT = 37,
> +};
> +
> +static const char *const trbe_ec_str[] = {
> + [TRBE_EC_OTHERS] = "Maintenance exception",
> + [TRBE_EC_STAGE1_ABORT] = "Stage-1 exception",
> + [TRBE_EC_STAGE2_ABORT] = "Stage-2 exception",
> +};
> +

Please remove the defintions that are not used by the driver.

> +static inline enum trbe_ec get_trbe_ec(void)
> +{
> + u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> + return (trbsr >> TRBSR_EC_SHIFT) & TRBSR_EC_MASK;
> +}
> +
> +static inline void clr_trbe_ec(void)
> +{
> + u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> + trbsr &= ~(TRBSR_EC_MASK << TRBSR_EC_SHIFT);
> + write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +enum trbe_bsc {
> + TRBE_BSC_NOT_STOPPED = 0,
> + TRBE_BSC_FILLED = 1,
> + TRBE_BSC_TRIGGERED = 2,
> +};
> +
> +static const char *const trbe_bsc_str[] = {
> + [TRBE_BSC_NOT_STOPPED] = "TRBE collection not stopped",
> + [TRBE_BSC_FILLED] = "TRBE filled",
> + [TRBE_BSC_TRIGGERED] = "TRBE triggered",
> +};
> +
> +static inline enum trbe_bsc get_trbe_bsc(void)
> +{
> + u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> + return (trbsr >> TRBSR_BSC_SHIFT) & TRBSR_BSC_MASK;
> +}
> +
> +static inline void clr_trbe_bsc(void)
> +{
> + u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> + trbsr &= ~(TRBSR_BSC_MASK << TRBSR_BSC_SHIFT);
> + write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +enum trbe_fsc {
> + TRBE_FSC_ASF_LEVEL0 = 0,
> + TRBE_FSC_ASF_LEVEL1 = 1,
> + TRBE_FSC_ASF_LEVEL2 = 2,
> + TRBE_FSC_ASF_LEVEL3 = 3,
> + TRBE_FSC_TF_LEVEL0 = 4,
> + TRBE_FSC_TF_LEVEL1 = 5,
> + TRBE_FSC_TF_LEVEL2 = 6,
> + TRBE_FSC_TF_LEVEL3 = 7,
> + TRBE_FSC_AFF_LEVEL0 = 8,
> + TRBE_FSC_AFF_LEVEL1 = 9,
> + TRBE_FSC_AFF_LEVEL2 = 10,
> + TRBE_FSC_AFF_LEVEL3 = 11,
> + TRBE_FSC_PF_LEVEL0 = 12,
> + TRBE_FSC_PF_LEVEL1 = 13,
> + TRBE_FSC_PF_LEVEL2 = 14,
> + TRBE_FSC_PF_LEVEL3 = 15,
> + TRBE_FSC_SEA_WRITE = 16,
> + TRBE_FSC_ASEA_WRITE = 17,
> + TRBE_FSC_SEA_LEVEL0 = 20,
> + TRBE_FSC_SEA_LEVEL1 = 21,
> + TRBE_FSC_SEA_LEVEL2 = 22,
> + TRBE_FSC_SEA_LEVEL3 = 23,
> + TRBE_FSC_ALIGN_FAULT = 33,
> + TRBE_FSC_TLB_FAULT = 48,
> + TRBE_FSC_ATOMIC_FAULT = 49,
> +};

Please remove ^^^

> +
> +static const char *const trbe_fsc_str[] = {
> + [TRBE_FSC_ASF_LEVEL0] = "Address size fault - level 0",
> + [TRBE_FSC_ASF_LEVEL1] = "Address size fault - level 1",
> + [TRBE_FSC_ASF_LEVEL2] = "Address size fault - level 2",
> + [TRBE_FSC_ASF_LEVEL3] = "Address size fault - level 3",
> + [TRBE_FSC_TF_LEVEL0] = "Translation fault - level 0",
> + [TRBE_FSC_TF_LEVEL1] = "Translation fault - level 1",
> + [TRBE_FSC_TF_LEVEL2] = "Translation fault - level 2",
> + [TRBE_FSC_TF_LEVEL3] = "Translation fault - level 3",
> + [TRBE_FSC_AFF_LEVEL0] = "Access flag fault - level 0",
> + [TRBE_FSC_AFF_LEVEL1] = "Access flag fault - level 1",
> + [TRBE_FSC_AFF_LEVEL2] = "Access flag fault - level 2",
> + [TRBE_FSC_AFF_LEVEL3] = "Access flag fault - level 3",
> + [TRBE_FSC_PF_LEVEL0] = "Permission fault - level 0",
> + [TRBE_FSC_PF_LEVEL1] = "Permission fault - level 1",
> + [TRBE_FSC_PF_LEVEL2] = "Permission fault - level 2",
> + [TRBE_FSC_PF_LEVEL3] = "Permission fault - level 3",
> + [TRBE_FSC_SEA_WRITE] = "Synchronous external abort on write",
> + [TRBE_FSC_ASEA_WRITE] = "Asynchronous external abort on write",
> + [TRBE_FSC_SEA_LEVEL0] = "Syncrhonous external abort on table walk - level 0",
> + [TRBE_FSC_SEA_LEVEL1] = "Syncrhonous external abort on table walk - level 1",
> + [TRBE_FSC_SEA_LEVEL2] = "Syncrhonous external abort on table walk - level 2",
> + [TRBE_FSC_SEA_LEVEL3] = "Syncrhonous external abort on table walk - level 3",
> + [TRBE_FSC_ALIGN_FAULT] = "Alignment fault",
> + [TRBE_FSC_TLB_FAULT] = "TLB conflict fault",
> + [TRBE_FSC_ATOMIC_FAULT] = "Atmoc fault",
> +};
>

Please remove ^^^

>

> +enum trbe_address_mode {
> + TRBE_ADDRESS_VIRTUAL,
> + TRBE_ADDRESS_PHYSICAL,
> +};

#define please.

> +
> +static const char *const trbe_address_mode_str[] = {
> + [TRBE_ADDRESS_VIRTUAL] = "Address mode - virtual",
> + [TRBE_ADDRESS_PHYSICAL] = "Address mode - physical",
> +};

Do we need this ? We always use virtual.

> +
> +static inline bool is_trbe_virtual_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + return !(trblimitr & TRBLIMITR_NVM);
> +}
> +

Remove

> +static inline bool is_trbe_physical_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + return trblimitr & TRBLIMITR_NVM;
> +}

Remove

> +
> +static inline void set_trbe_virtual_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr &= ~TRBLIMITR_NVM;
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +

> +static inline void set_trbe_physical_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr |= TRBLIMITR_NVM;
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}

Remove

> +
> +enum trbe_trig_mode {
> + TRBE_TRIGGER_STOP = 0,
> + TRBE_TRIGGER_IRQ = 1,
> + TRBE_TRIGGER_IGNORE = 3,
> +};
> +
> +static const char *const trbe_trig_mode_str[] = {
> + [TRBE_TRIGGER_STOP] = "Trigger mode - stop",
> + [TRBE_TRIGGER_IRQ] = "Trigger mode - irq",
> + [TRBE_TRIGGER_IGNORE] = "Trigger mode - ignore",
> +};
> +
> +static inline enum trbe_trig_mode get_trbe_trig_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + return (trblimitr >> TRBLIMITR_TRIG_MODE_SHIFT) & TRBLIMITR_TRIG_MODE_MASK;
> +}
> +
> +static inline void set_trbe_trig_mode(enum trbe_trig_mode mode)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr &= ~(TRBLIMITR_TRIG_MODE_MASK << TRBLIMITR_TRIG_MODE_SHIFT);
> + trblimitr |= ((mode & TRBLIMITR_TRIG_MODE_MASK) << TRBLIMITR_TRIG_MODE_SHIFT);
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +
> +enum trbe_fill_mode {
> + TRBE_FILL_STOP = 0,
> + TRBE_FILL_WRAP = 1,
> + TRBE_FILL_CIRCULAR = 3,
> +};
> +

Please use #define

> +static const char *const trbe_fill_mode_str[] = {
> + [TRBE_FILL_STOP] = "Buffer mode - stop",
> + [TRBE_FILL_WRAP] = "Buffer mode - wrap",
> + [TRBE_FILL_CIRCULAR] = "Buffer mode - circular",
> +};
> +
> +static inline enum trbe_fill_mode get_trbe_fill_mode(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + return (trblimitr >> TRBLIMITR_FILL_MODE_SHIFT) & TRBLIMITR_FILL_MODE_MASK;
> +}
> +
> +static inline void set_trbe_fill_mode(enum trbe_fill_mode mode)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr &= ~(TRBLIMITR_FILL_MODE_MASK << TRBLIMITR_FILL_MODE_SHIFT);
> + trblimitr |= ((mode & TRBLIMITR_FILL_MODE_MASK) << TRBLIMITR_FILL_MODE_SHIFT);
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +
> +static inline void set_trbe_disabled(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr &= ~TRBLIMITR_ENABLE;
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +
> +static inline void set_trbe_enabled(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + trblimitr |= TRBLIMITR_ENABLE;
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +
> +static inline bool get_trbe_flag_update(void)
> +{
> + u64 trbidr = read_sysreg_s(SYS_TRBIDR_EL1);
> +
> + return trbidr & TRBIDR_FLAG;
> +}
> +
> +static inline bool is_trbe_programmable(void)
> +{
> + u64 trbidr = read_sysreg_s(SYS_TRBIDR_EL1);
> +
> + return !(trbidr & TRBIDR_PROG);
> +}
> +#
> +enum trbe_buffer_align {
> + TRBE_BUFFER_BYTE,
> + TRBE_BUFFER_HALF_WORD,
> + TRBE_BUFFER_WORD,
> + TRBE_BUFFER_DOUBLE_WORD,
> + TRBE_BUFFER_16_BYTES,
> + TRBE_BUFFER_32_BYTES,
> + TRBE_BUFFER_64_BYTES,
> + TRBE_BUFFER_128_BYTES,
> + TRBE_BUFFER_256_BYTES,
> + TRBE_BUFFER_512_BYTES,
> + TRBE_BUFFER_1K_BYTES,
> + TRBE_BUFFER_2K_BYTES,
> +};
> +

Remove ^^

> +static const char *const trbe_buffer_align_str[] = {
> + [TRBE_BUFFER_BYTE] = "Byte",
> + [TRBE_BUFFER_HALF_WORD] = "Half word",
> + [TRBE_BUFFER_WORD] = "Word",
> + [TRBE_BUFFER_DOUBLE_WORD] = "Double word",
> + [TRBE_BUFFER_16_BYTES] = "16 bytes",
> + [TRBE_BUFFER_32_BYTES] = "32 bytes",
> + [TRBE_BUFFER_64_BYTES] = "64 bytes",
> + [TRBE_BUFFER_128_BYTES] = "128 bytes",
> + [TRBE_BUFFER_256_BYTES] = "256 bytes",
> + [TRBE_BUFFER_512_BYTES] = "512 bytes",
> + [TRBE_BUFFER_1K_BYTES] = "1K bytes",
> + [TRBE_BUFFER_2K_BYTES] = "2K bytes",
> +};

We don't need any of this. We could simply "<<" and get the
size.


> +
> +static inline enum trbe_buffer_align get_trbe_address_align(void)
> +{
> + u64 trbidr = read_sysreg_s(SYS_TRBIDR_EL1);
> +
> + return (trbidr >> TRBIDR_ALIGN_SHIFT) & TRBIDR_ALIGN_MASK;
> +}
> +
> +static inline void assert_trbe_address_mode(unsigned long addr)
> +{
> + bool virt_addr = virt_addr_valid(addr) || is_vmalloc_addr((void *)addr);
> + bool virt_mode = is_trbe_virtual_mode();
> +
> + WARN_ON(addr && ((virt_addr && !virt_mode) || (!virt_addr && virt_mode)));
> +}

I am not sure if this is really helpful. You have to trust the kernel vmalloc().

> +
> +static inline void assert_trbe_address_align(unsigned long addr)
> +{
> + unsigned long nr_bytes = 1ULL << get_trbe_address_align();
> +
> + WARN_ON(addr & (nr_bytes - 1));
> +}
> +
> +static inline unsigned long get_trbe_write_pointer(void)
> +{
> + u64 trbptr = read_sysreg_s(SYS_TRBPTR_EL1);
> + unsigned long addr = (trbptr >> TRBPTR_PTR_SHIFT) & TRBPTR_PTR_MASK;
> +
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + return addr;
> +}
> +
> +static inline void set_trbe_write_pointer(unsigned long addr)
> +{
> + WARN_ON(is_trbe_enabled());
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + addr = (addr >> TRBPTR_PTR_SHIFT) & TRBPTR_PTR_MASK;
> + write_sysreg_s(addr, SYS_TRBPTR_EL1);
> +}
> +
> +static inline unsigned long get_trbe_limit_pointer(void)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> + unsigned long limit = (trblimitr >> TRBLIMITR_LIMIT_SHIFT) & TRBLIMITR_LIMIT_MASK;
> + unsigned long addr = limit << TRBLIMITR_LIMIT_SHIFT;
> +
> + WARN_ON(addr & (PAGE_SIZE - 1));
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + return addr;
> +}
> +
> +static inline void set_trbe_limit_pointer(unsigned long addr)
> +{
> + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> + WARN_ON(is_trbe_enabled());
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + WARN_ON(addr & ((1UL << TRBLIMITR_LIMIT_SHIFT) - 1));
> + WARN_ON(addr & (PAGE_SIZE - 1));
> + trblimitr &= ~(TRBLIMITR_LIMIT_MASK << TRBLIMITR_LIMIT_SHIFT);
> + trblimitr |= (addr & PAGE_MASK);
> + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
> +}
> +
> +static inline unsigned long get_trbe_base_pointer(void)
> +{
> + u64 trbbaser = read_sysreg_s(SYS_TRBBASER_EL1);
> + unsigned long addr = (trbbaser >> TRBBASER_BASE_SHIFT) & TRBBASER_BASE_MASK;
> +
> + addr = addr << TRBBASER_BASE_SHIFT;
> + WARN_ON(addr & (PAGE_SIZE - 1));
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + return addr;
> +}
> +
> +static inline void set_trbe_base_pointer(unsigned long addr)
> +{
> + WARN_ON(is_trbe_enabled());
> + assert_trbe_address_mode(addr);
> + assert_trbe_address_align(addr);
> + WARN_ON(addr & ((1UL << TRBBASER_BASE_SHIFT) - 1));
> + WARN_ON(addr & (PAGE_SIZE - 1));
> + write_sysreg_s(addr, SYS_TRBBASER_EL1);
> +}
>

Suzuki

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