Hi Anshuman,

On Tue, Nov 10, 2020 at 08:45:05PM +0800, 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.khand...@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.khand...@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"

Can you consider to support TRBE as loadable module since all coresight
drivers support loadable module now.

Thanks
Tingwei

> +     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.khand...@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
> +
> +static const char trbe_name[] = "trbe";
> +
> +enum trbe_fault_action {
> +     TRBE_FAULT_ACT_WRAP,
> +     TRBE_FAULT_ACT_SPURIOUS,
> +     TRBE_FAULT_ACT_FATAL,
> +};
> +
> +struct trbe_perf {
> +     unsigned long trbe_base;
> +     unsigned long trbe_limit;
> +     unsigned long trbe_write;
> +     pid_t pid;
> +     int nr_pages;
> +     void **pages;
> +     bool snapshot;
> +     struct trbe_cpudata *cpudata;
> +};
> +
> +struct trbe_cpudata {
> +     struct coresight_device *csdev;
> +     bool trbe_dbm;
> +     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;
> +     struct hlist_node hotplug_node;
> +     int irq;
> +     cpumask_t supported_cpus;
> +     enum cpuhp_state trbe_online;
> +     struct platform_device *pdev;
> +     struct clk *atclk;
> +};
> +
> +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;
> +
> +     if (head < limit >> 1)
> +             limit >>= 1;
> +
> +     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;
> +
> +     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)
> +             limit = round_down(tail, PAGE_SIZE);
> +
> +     if (handle->wakeup < (handle->head + handle->size) && head <= wakeup)
> +             limit = min(limit, round_up(wakeup, 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();
> +     set_trbe_virtual_mode();
> +     set_trbe_fill_mode(TRBE_FILL_STOP);
> +     set_trbe_trig_mode(TRBE_TRIGGER_IGNORE);
> +     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();
> +     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)))
> +             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);
> +     WARN_ON(cpudata->drvdata != drvdata);
> +
> +     *this_cpu_ptr(drvdata->handle) = *handle;
> +     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;
> +     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;
> +     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 const struct coresight_ops_sink arm_trbe_sink_ops = {
> +     .enable         = arm_trbe_enable,
> +     .disable        = arm_trbe_disable,
> +     .alloc_buffer   = arm_trbe_alloc_buffer,
> +     .free_buffer    = arm_trbe_free_buffer,
> +     .update_buffer  = arm_trbe_update_buffer,
> +};
> +
> +static const struct coresight_ops arm_trbe_cs_ops = {
> +     .sink_ops       = &arm_trbe_sink_ops,
> +};
> +
> +static ssize_t irq_show(struct device *dev, struct device_attribute *attr, 
> char *buf)
> +{
> +     struct trbe_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +     return sprintf(buf, "%d\n", drvdata->irq);
> +}
> +static DEVICE_ATTR_RO(irq);
> +
> +static ssize_t align_show(struct device *dev, struct device_attribute 
> *attr, char *buf)
> +{
> +     struct trbe_cpudata *cpudata = dev_get_drvdata(dev);
> +
> +     return sprintf(buf, "%s\n", 
> trbe_buffer_align_str[ilog2(cpudata->trbe_align)]);
> +}
> +static DEVICE_ATTR_RO(align);
> +
> +static ssize_t dbm_show(struct device *dev, struct device_attribute *attr, 
> char *buf)
> +{
> +     struct trbe_cpudata *cpudata = dev_get_drvdata(dev);
> +
> +     return sprintf(buf, "%d\n", cpudata->trbe_dbm);
> +}
> +static DEVICE_ATTR_RO(dbm);
> +
> +static struct attribute *arm_trbe_attrs[] = {
> +     &dev_attr_align.attr,
> +     &dev_attr_irq.attr,
> +     &dev_attr_dbm.attr,
> +     NULL,
> +};
> +
> +static const struct attribute_group arm_trbe_group = {
> +     .attrs = arm_trbe_attrs,
> +};
> +
> +static const struct attribute_group *arm_trbe_groups[] = {
> +     &arm_trbe_group,
> +     NULL,
> +};
> +
> +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;
> +     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);
> +     }
> +     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;
> +             }
> +     }
> +     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);
> +             }
> +             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;
> +     }
> +     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);
> +
> +     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);
> +
> +     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 },
> +     {},
> +};
> +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);
> +
> +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)
> 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.khand...@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);
> +}
> +
> +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",
> +};
> +
> +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,
> +};
> +
> +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",
> +};
> +
> +static inline enum trbe_fsc get_trbe_fsc(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return (trbsr >> TRBSR_FSC_SHIFT) & TRBSR_FSC_MASK;
> +}
> +
> +static inline void clr_trbe_fsc(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     trbsr &= ~(TRBSR_FSC_MASK << TRBSR_FSC_SHIFT);
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void set_trbe_irq(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr |= TRBSR_IRQ;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void clr_trbe_irq(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     trbsr &= ~TRBSR_IRQ;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void set_trbe_trg(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr |= TRBSR_TRG;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void clr_trbe_trg(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr &= ~TRBSR_TRG;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void set_trbe_wrap(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr |= TRBSR_WRAP;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void clr_trbe_wrap(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr &= ~TRBSR_WRAP;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void set_trbe_abort(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr |= TRBSR_ABORT;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline void clr_trbe_abort(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     WARN_ON(is_trbe_enabled());
> +     trbsr &= ~TRBSR_ABORT;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +static inline bool is_trbe_irq(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return trbsr & TRBSR_IRQ;
> +}
> +
> +static inline bool is_trbe_trg(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return trbsr & TRBSR_TRG;
> +}
> +
> +static inline bool is_trbe_wrap(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return trbsr & TRBSR_WRAP;
> +}
> +
> +static inline bool is_trbe_abort(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return trbsr & TRBSR_ABORT;
> +}
> +
> +static inline bool is_trbe_running(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     return !(trbsr & TRBSR_STOP);
> +}
> +
> +static inline void set_trbe_running(void)
> +{
> +     u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
> +
> +     trbsr &= ~TRBSR_STOP;
> +     write_sysreg_s(trbsr, SYS_TRBSR_EL1);
> +}
> +
> +enum trbe_address_mode {
> +     TRBE_ADDRESS_VIRTUAL,
> +     TRBE_ADDRESS_PHYSICAL,
> +};
> +
> +static const char *const trbe_address_mode_str[] = {
> +     [TRBE_ADDRESS_VIRTUAL]  = "Address mode - virtual",
> +     [TRBE_ADDRESS_PHYSICAL] = "Address mode - physical",
> +};
> +
> +static inline bool is_trbe_virtual_mode(void)
> +{
> +     u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> +     return !(trblimitr & TRBLIMITR_NVM);
> +}
> +
> +static inline bool is_trbe_physical_mode(void)
> +{
> +     u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
> +
> +     return trblimitr & TRBLIMITR_NVM;
> +}
> +
> +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);
> +}
> +
> +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,
> +};
> +
> +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,
> +};
> +
> +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",
> +};
> +
> +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)));
> +}
> +
> +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);
> +}
> -- 
> 2.7.4
> 
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