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authorLinus Torvalds <torvalds@linux-foundation.org>2021-05-01 10:14:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-01 10:14:08 -0700
commit152d32aa846835987966fd20ee1143b0e05036a0 (patch)
tree728cfb095b62bb3cb3ede5ff12f70d0042db49d4 /drivers/hwtracing
parent4f9701057a9cc1ae6bfc533204c9d3ba386687de (diff)
parent3bf0fcd754345d7ea63e1446015ba65ece6788ca (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/Kconfig24
-rw-r--r--drivers/hwtracing/coresight/Makefile1
-rw-r--r--drivers/hwtracing/coresight/coresight-core.c29
-rw-r--r--drivers/hwtracing/coresight/coresight-etm-perf.c119
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x-core.c161
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x-sysfs.c19
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x.h83
-rw-r--r--drivers/hwtracing/coresight/coresight-platform.c6
-rw-r--r--drivers/hwtracing/coresight/coresight-priv.h3
-rw-r--r--drivers/hwtracing/coresight/coresight-trbe.c1157
-rw-r--r--drivers/hwtracing/coresight/coresight-trbe.h152
11 files changed, 1698 insertions, 56 deletions
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 7b44ba22cbe1..84530fd80998 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -97,15 +97,15 @@ config CORESIGHT_SOURCE_ETM3X
module will be called coresight-etm3x.
config CORESIGHT_SOURCE_ETM4X
- tristate "CoreSight Embedded Trace Macrocell 4.x driver"
+ tristate "CoreSight ETMv4.x / ETE driver"
depends on ARM64
select CORESIGHT_LINKS_AND_SINKS
select PID_IN_CONTEXTIDR
help
- This driver provides support for the ETM4.x tracer module, tracing the
- instructions that a processor is executing. This is primarily useful
- for instruction level tracing. Depending on the implemented version
- data tracing may also be available.
+ This driver provides support for the CoreSight Embedded Trace Macrocell
+ version 4.x and the Embedded Trace Extensions (ETE). Both are CPU tracer
+ modules, tracing the instructions that a processor is executing. This is
+ primarily useful for instruction level tracing.
To compile this driver as a module, choose M here: the
module will be called coresight-etm4x.
@@ -173,4 +173,18 @@ config CORESIGHT_CTI_INTEGRATION_REGS
CTI trigger connections between this and other devices.These
registers are not used in normal operation and can leave devices in
an inconsistent state.
+
+config CORESIGHT_TRBE
+ tristate "Trace Buffer Extension (TRBE) driver"
+ depends on ARM64 && CORESIGHT_SOURCE_ETM4X
+ 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.
+
+ To compile this driver as a module, choose M here: the module will be
+ called coresight-trbe.
endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index f20e357758d1..d60816509755 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-core.c b/drivers/hwtracing/coresight/coresight-core.c
index b57bea167102..6c68d34d956e 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -23,6 +23,7 @@
#include "coresight-priv.h"
static DEFINE_MUTEX(coresight_mutex);
+static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
/**
* struct coresight_node - elements of a path, from source to sink
@@ -70,6 +71,18 @@ void coresight_remove_cti_ops(void)
}
EXPORT_SYMBOL_GPL(coresight_remove_cti_ops);
+void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev)
+{
+ per_cpu(csdev_sink, cpu) = csdev;
+}
+EXPORT_SYMBOL_GPL(coresight_set_percpu_sink);
+
+struct coresight_device *coresight_get_percpu_sink(int cpu)
+{
+ return per_cpu(csdev_sink, cpu);
+}
+EXPORT_SYMBOL_GPL(coresight_get_percpu_sink);
+
static int coresight_id_match(struct device *dev, void *data)
{
int trace_id, i_trace_id;
@@ -784,6 +797,14 @@ static int _coresight_build_path(struct coresight_device *csdev,
if (csdev == sink)
goto out;
+ if (coresight_is_percpu_source(csdev) && coresight_is_percpu_sink(sink) &&
+ sink == per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev))) {
+ if (_coresight_build_path(sink, sink, path) == 0) {
+ found = true;
+ goto out;
+ }
+ }
+
/* Not a sink - recursively explore each port found on this element */
for (i = 0; i < csdev->pdata->nr_outport; i++) {
struct coresight_device *child_dev;
@@ -999,8 +1020,12 @@ coresight_find_default_sink(struct coresight_device *csdev)
int depth = 0;
/* look for a default sink if we have not found for this device */
- if (!csdev->def_sink)
- csdev->def_sink = coresight_find_sink(csdev, &depth);
+ if (!csdev->def_sink) {
+ if (coresight_is_percpu_source(csdev))
+ csdev->def_sink = per_cpu(csdev_sink, source_ops(csdev)->cpu_id(csdev));
+ if (!csdev->def_sink)
+ csdev->def_sink = coresight_find_sink(csdev, &depth);
+ }
return csdev->def_sink;
}
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index c1bec2ad3911..6f398377fec9 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -24,7 +24,26 @@
static struct pmu etm_pmu;
static bool etm_perf_up;
-static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle);
+/*
+ * An ETM context for a running event includes the perf aux handle
+ * and aux_data. For ETM, the aux_data (etm_event_data), consists of
+ * the trace path and the sink configuration. The event data is accessible
+ * via perf_get_aux(handle). However, a sink could "end" a perf output
+ * handle via the IRQ handler. And if the "sink" encounters a failure
+ * to "begin" another session (e.g due to lack of space in the buffer),
+ * the handle will be cleared. Thus, the event_data may not be accessible
+ * from the handle when we get to the etm_event_stop(), which is required
+ * for stopping the trace path. The event_data is guaranteed to stay alive
+ * until "free_aux()", which cannot happen as long as the event is active on
+ * the ETM. Thus the event_data for the session must be part of the ETM context
+ * to make sure we can disable the trace path.
+ */
+struct etm_ctxt {
+ struct perf_output_handle handle;
+ struct etm_event_data *event_data;
+};
+
+static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt);
static DEFINE_PER_CPU(struct coresight_device *, csdev_src);
/*
@@ -232,6 +251,25 @@ static void etm_free_aux(void *data)
schedule_work(&event_data->work);
}
+/*
+ * Check if two given sinks are compatible with each other,
+ * so that they can use the same sink buffers, when an event
+ * moves around.
+ */
+static bool sinks_compatible(struct coresight_device *a,
+ struct coresight_device *b)
+{
+ if (!a || !b)
+ return false;
+ /*
+ * If the sinks are of the same subtype and driven
+ * by the same driver, we can use the same buffer
+ * on these sinks.
+ */
+ return (a->subtype.sink_subtype == b->subtype.sink_subtype) &&
+ (sink_ops(a) == sink_ops(b));
+}
+
static void *etm_setup_aux(struct perf_event *event, void **pages,
int nr_pages, bool overwrite)
{
@@ -239,6 +277,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
int cpu = event->cpu;
cpumask_t *mask;
struct coresight_device *sink = NULL;
+ struct coresight_device *user_sink = NULL, *last_sink = NULL;
struct etm_event_data *event_data = NULL;
event_data = alloc_event_data(cpu);
@@ -249,7 +288,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
/* First get the selected sink from user space. */
if (event->attr.config2) {
id = (u32)event->attr.config2;
- sink = coresight_get_sink_by_id(id);
+ sink = user_sink = coresight_get_sink_by_id(id);
}
mask = &event_data->mask;
@@ -277,14 +316,33 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
}
/*
- * No sink provided - look for a default sink for one of the
- * devices. At present we only support topology where all CPUs
- * use the same sink [N:1], so only need to find one sink. The
- * coresight_build_path later will remove any CPU that does not
- * attach to the sink, or if we have not found a sink.
+ * No sink provided - look for a default sink for all the ETMs,
+ * where this event can be scheduled.
+ * We allocate the sink specific buffers only once for this
+ * event. If the ETMs have different default sink devices, we
+ * can only use a single "type" of sink as the event can carry
+ * only one sink specific buffer. Thus we have to make sure
+ * that the sinks are of the same type and driven by the same
+ * driver, as the one we allocate the buffer for. As such
+ * we choose the first sink and check if the remaining ETMs
+ * have a compatible default sink. We don't trace on a CPU
+ * if the sink is not compatible.
*/
- if (!sink)
+ if (!user_sink) {
+ /* Find the default sink for this ETM */
sink = coresight_find_default_sink(csdev);
+ if (!sink) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
+
+ /* Check if this sink compatible with the last sink */
+ if (last_sink && !sinks_compatible(last_sink, sink)) {
+ cpumask_clear_cpu(cpu, mask);
+ continue;
+ }
+ last_sink = sink;
+ }
/*
* Building a path doesn't enable it, it simply builds a
@@ -312,7 +370,12 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
if (!sink_ops(sink)->alloc_buffer || !sink_ops(sink)->free_buffer)
goto err;
- /* Allocate the sink buffer for this session */
+ /*
+ * Allocate the sink buffer for this session. All the sinks
+ * where this event can be scheduled are ensured to be of the
+ * same type. Thus the same sink configuration is used by the
+ * sinks.
+ */
event_data->snk_config =
sink_ops(sink)->alloc_buffer(sink, event, pages,
nr_pages, overwrite);
@@ -332,13 +395,18 @@ static void etm_event_start(struct perf_event *event, int flags)
{
int cpu = smp_processor_id();
struct etm_event_data *event_data;
- struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
+ struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
+ struct perf_output_handle *handle = &ctxt->handle;
struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
struct list_head *path;
if (!csdev)
goto fail;
+ /* Have we messed up our tracking ? */
+ if (WARN_ON(ctxt->event_data))
+ goto fail;
+
/*
* Deal with the ring buffer API and get a handle on the
* session's information.
@@ -374,6 +442,8 @@ static void etm_event_start(struct perf_event *event, int flags)
if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
goto fail_disable_path;
+ /* Save the event_data for this ETM */
+ ctxt->event_data = event_data;
out:
return;
@@ -392,13 +462,30 @@ static void etm_event_stop(struct perf_event *event, int mode)
int cpu = smp_processor_id();
unsigned long size;
struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
- struct perf_output_handle *handle = this_cpu_ptr(&ctx_handle);
- struct etm_event_data *event_data = perf_get_aux(handle);
+ struct etm_ctxt *ctxt = this_cpu_ptr(&etm_ctxt);
+ struct perf_output_handle *handle = &ctxt->handle;
+ struct etm_event_data *event_data;
struct list_head *path;
+ /*
+ * If we still have access to the event_data via handle,
+ * confirm that we haven't messed up the tracking.
+ */
+ if (handle->event &&
+ WARN_ON(perf_get_aux(handle) != ctxt->event_data))
+ return;
+
+ event_data = ctxt->event_data;
+ /* Clear the event_data as this ETM is stopping the trace. */
+ ctxt->event_data = NULL;
+
if (event->hw.state == PERF_HES_STOPPED)
return;
+ /* We must have a valid event_data for a running event */
+ if (WARN_ON(!event_data))
+ return;
+
if (!csdev)
return;
@@ -416,7 +503,13 @@ static void etm_event_stop(struct perf_event *event, int mode)
/* tell the core */
event->hw.state = PERF_HES_STOPPED;
- if (mode & PERF_EF_UPDATE) {
+ /*
+ * If the handle is not bound to an event anymore
+ * (e.g, the sink driver was unable to restart the
+ * handle due to lack of buffer space), we don't
+ * have to do anything here.
+ */
+ if (handle->event && (mode & PERF_EF_UPDATE)) {
if (WARN_ON_ONCE(handle->event != event))
return;
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index a5b13a7779c3..db881993c211 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -31,6 +31,7 @@
#include <linux/pm_runtime.h>
#include <linux/property.h>
+#include <asm/barrier.h>
#include <asm/sections.h>
#include <asm/sysreg.h>
#include <asm/local.h>
@@ -114,30 +115,91 @@ void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit)
}
}
-static void etm4_os_unlock_csa(struct etmv4_drvdata *drvdata, struct csdev_access *csa)
+static u64 ete_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
{
- /* Writing 0 to TRCOSLAR unlocks the trace registers */
- etm4x_relaxed_write32(csa, 0x0, TRCOSLAR);
- drvdata->os_unlock = true;
+ u64 res = 0;
+
+ switch (offset) {
+ ETE_READ_CASES(res)
+ default :
+ pr_warn_ratelimited("ete: trying to read unsupported register @%x\n",
+ offset);
+ }
+
+ if (!_relaxed)
+ __iormb(res); /* Imitate the !relaxed I/O helpers */
+
+ return res;
+}
+
+static void ete_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit)
+{
+ if (!_relaxed)
+ __iowmb(); /* Imitate the !relaxed I/O helpers */
+ if (!_64bit)
+ val &= GENMASK(31, 0);
+
+ switch (offset) {
+ ETE_WRITE_CASES(val)
+ default :
+ pr_warn_ratelimited("ete: trying to write to unsupported register @%x\n",
+ offset);
+ }
+}
+
+static void etm_detect_os_lock(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa)
+{
+ u32 oslsr = etm4x_relaxed_read32(csa, TRCOSLSR);
+
+ drvdata->os_lock_model = ETM_OSLSR_OSLM(oslsr);
+}
+
+static void etm_write_os_lock(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa, u32 val)
+{
+ val = !!val;
+
+ switch (drvdata->os_lock_model) {
+ case ETM_OSLOCK_PRESENT:
+ etm4x_relaxed_write32(csa, val, TRCOSLAR);
+ break;
+ case ETM_OSLOCK_PE:
+ write_sysreg_s(val, SYS_OSLAR_EL1);
+ break;
+ default:
+ pr_warn_once("CPU%d: Unsupported Trace OSLock model: %x\n",
+ smp_processor_id(), drvdata->os_lock_model);
+ fallthrough;
+ case ETM_OSLOCK_NI:
+ return;
+ }
isb();
}
+static inline void etm4_os_unlock_csa(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa)
+{
+ WARN_ON(drvdata->cpu != smp_processor_id());
+
+ /* Writing 0 to OS Lock unlocks the trace unit registers */
+ etm_write_os_lock(drvdata, csa, 0x0);
+ drvdata->os_unlock = true;
+}
+
static void etm4_os_unlock(struct etmv4_drvdata *drvdata)
{
if (!WARN_ON(!drvdata->csdev))
etm4_os_unlock_csa(drvdata, &drvdata->csdev->access);
-
}
static void etm4_os_lock(struct etmv4_drvdata *drvdata)
{
if (WARN_ON(!drvdata->csdev))
return;
-
- /* Writing 0x1 to TRCOSLAR locks the trace registers */
- etm4x_relaxed_write32(&drvdata->csdev->access, 0x1, TRCOSLAR);
+ /* Writing 0x1 to OS Lock locks the trace registers */
+ etm_write_os_lock(drvdata, &drvdata->csdev->access, 0x1);
drvdata->os_unlock = false;
- isb();
}
static void etm4_cs_lock(struct etmv4_drvdata *drvdata,
@@ -371,6 +433,13 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
etm4x_relaxed_write32(csa, trcpdcr | TRCPDCR_PU, TRCPDCR);
}
+ /*
+ * ETE mandates that the TRCRSR is written to before
+ * enabling it.
+ */
+ if (etm4x_is_ete(drvdata))
+ etm4x_relaxed_write32(csa, TRCRSR_TA, TRCRSR);
+
/* Enable the trace unit */
etm4x_relaxed_write32(csa, 1, TRCPRGCTLR);
@@ -654,6 +723,7 @@ static int etm4_enable(struct coresight_device *csdev,
static void etm4_disable_hw(void *info)
{
u32 control;
+ u64 trfcr;
struct etmv4_drvdata *drvdata = info;
struct etmv4_config *config = &drvdata->config;
struct coresight_device *csdev = drvdata->csdev;
@@ -677,18 +747,32 @@ static void etm4_disable_hw(void *info)
control &= ~0x1;
/*
+ * If the CPU supports v8.4 Trace filter Control,
+ * set the ETM to trace prohibited region.
+ */
+ if (drvdata->trfc) {
+ trfcr = read_sysreg_s(SYS_TRFCR_EL1);
+ write_sysreg_s(trfcr & ~(TRFCR_ELx_ExTRE | TRFCR_ELx_E0TRE),
+ SYS_TRFCR_EL1);
+ isb();
+ }
+ /*
* Make sure everything completes before disabling, as recommended
* by section 7.3.77 ("TRCVICTLR, ViewInst Main Control Register,
* SSTATUS") of ARM IHI 0064D
*/
dsb(sy);
isb();
+ /* Trace synchronization barrier, is a nop if not supported */
+ tsb_csync();
etm4x_relaxed_write32(csa, control, TRCPRGCTLR);
/* wait for TRCSTATR.PMSTABLE to go to '1' */
if (coresight_timeout(csa, TRCSTATR, TRCSTATR_PMSTABLE_BIT, 1))
dev_err(etm_dev,
"timeout while waiting for PM stable Trace Status\n");
+ if (drvdata->trfc)
+ write_sysreg_s(trfcr, SYS_TRFCR_EL1);
/* read the status of the single shot comparators */
for (i = 0; i < drvdata->nr_ss_cmp; i++) {
@@ -817,13 +901,24 @@ static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
* ETMs implementing sysreg access must implement TRCDEVARCH.
*/
devarch = read_etm4x_sysreg_const_offset(TRCDEVARCH);
- if ((devarch & ETM_DEVARCH_ID_MASK) != ETM_DEVARCH_ETMv4x_ARCH)
+ switch (devarch & ETM_DEVARCH_ID_MASK) {
+ case ETM_DEVARCH_ETMv4x_ARCH:
+ *csa = (struct csdev_access) {
+ .io_mem = false,
+ .read = etm4x_sysreg_read,
+ .write = etm4x_sysreg_write,
+ };
+ break;
+ case ETM_DEVARCH_ETE_ARCH:
+ *csa = (struct csdev_access) {
+ .io_mem = false,
+ .read = ete_sysreg_read,
+ .write = ete_sysreg_write,
+ };
+ break;
+ default:
return false;
- *csa = (struct csdev_access) {
- .io_mem = false,
- .read = etm4x_sysreg_read,
- .write = etm4x_sysreg_write,
- };
+ }
drvdata->arch = etm_devarch_to_arch(devarch);
return true;
@@ -873,7 +968,7 @@ static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata,
return false;
}
-static void cpu_enable_tracing(void)
+static void cpu_enable_tracing(struct etmv4_drvdata *drvdata)
{
u64 dfr0 = read_sysreg(id_aa64dfr0_el1);
u64 trfcr;
@@ -881,6 +976,7 @@ static void cpu_enable_tracing(void)
if (!cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRACE_FILT_SHIFT))
return;
+ drvdata->trfc = true;
/*
* If the CPU supports v8.4 SelfHosted Tracing, enable
* tracing at the kernel EL and EL0, forcing to use the
@@ -920,6 +1016,9 @@ static void etm4_init_arch_data(void *info)
if (!etm4_init_csdev_access(drvdata, csa))
return;
+ /* Detect the support for OS Lock before we actually use it */
+ etm_detect_os_lock(drvdata, csa);
+
/* Make sure all registers are accessible */
etm4_os_unlock_csa(drvdata, csa);
etm4_cs_unlock(drvdata, csa);
@@ -1082,7 +1181,7 @@ static void etm4_init_arch_data(void *info)
/* NUMCNTR, bits[30:28] number of counters available for tracing */
drvdata->nr_cntr = BMVAL(etmidr5, 28, 30);
etm4_cs_lock(drvdata, csa);
- cpu_enable_tracing();
+ cpu_enable_tracing(drvdata);
}
static inline u32 etm4_get_victlr_access_type(struct etmv4_config *config)
@@ -1760,6 +1859,8 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
struct etmv4_drvdata *drvdata;
struct coresight_desc desc = { 0 };
struct etm4_init_arg init_arg = { 0 };
+ u8 major, minor;
+ char *type_name;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
@@ -1786,10 +1887,6 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
if (drvdata->cpu < 0)
return drvdata->cpu;
- desc.name = devm_kasprintf(dev, GFP_KERNEL, "etm%d", drvdata->cpu);
- if (!desc.name)
- return -ENOMEM;
-
init_arg.drvdata = drvdata;
init_arg.csa = &desc.access;
init_arg.pid = etm_pid;
@@ -1806,6 +1903,22 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
drvdata->skip_power_up = true;
+ major = ETM_ARCH_MAJOR_VERSION(drvdata->arch);
+ minor = ETM_ARCH_MINOR_VERSION(drvdata->arch);
+
+ if (etm4x_is_ete(drvdata)) {
+ type_name = "ete";
+ /* ETE v1 has major version == 0b101. Adjust this for logging.*/
+ major -= 4;
+ } else {
+ type_name = "etm";
+ }
+
+ desc.name = devm_kasprintf(dev, GFP_KERNEL,
+ "%s%d", type_name, drvdata->cpu);
+ if (!desc.name)
+ return -ENOMEM;
+
etm4_init_trace_id(drvdata);
etm4_set_default(&drvdata->config);
@@ -1833,9 +1946,8 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
etmdrvdata[drvdata->cpu] = drvdata;
- dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n",
- drvdata->cpu, ETM_ARCH_MAJOR_VERSION(drvdata->arch),
- ETM_ARCH_MINOR_VERSION(drvdata->arch));
+ dev_info(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n",
+ drvdata->cpu, type_name, major, minor);
if (boot_enable) {
coresight_enable(drvdata->csdev);
@@ -1979,6 +2091,7 @@ static struct amba_driver etm4x_amba_driver = {
static const struct of_device_id etm4_sysreg_match[] = {
{ .compatible = "arm,coresight-etm4x-sysreg" },
+ { .compatible = "arm,embedded-trace-extension" },
{}
};
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 0995a10790f4..007bad9e7ad8 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -2374,12 +2374,20 @@ static inline bool
etm4x_register_implemented(struct etmv4_drvdata *drvdata, u32 offset)
{
switch (offset) {
- ETM4x_SYSREG_LIST_CASES
+ ETM_COMMON_SYSREG_LIST_CASES
/*
- * Registers accessible via system instructions are always
- * implemented.
+ * Common registers to ETE & ETM4x accessible via system
+ * instructions are always implemented.
*/
return true;
+
+ ETM4x_ONLY_SYSREG_LIST_CASES
+ /*
+ * We only support etm4x and ete. So if the device is not
+ * ETE, it must be ETMv4x.
+ */
+ return !etm4x_is_ete(drvdata);
+
ETM4x_MMAP_LIST_CASES
/*
* Registers accessible only via memory-mapped registers
@@ -2389,8 +2397,13 @@ etm4x_register_implemented(struct etmv4_drvdata *drvdata, u32 offset)
* coresight_register() and the csdev is not initialized
* until that is done. So rely on the drvdata->base to
* detect if we have a memory mapped access.
+ * Also ETE doesn't implement memory mapped access, thus
+ * it is sufficient to check that we are using mmio.
*/
return !!drvdata->base;
+
+ ETE_ONLY_SYSREG_LIST_CASES
+ return etm4x_is_ete(drvdata);
}
return false;
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 0af60571aa23..e5b79bdb9851 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -29,6 +29,7 @@
#define TRCAUXCTLR 0x018
#define TRCEVENTCTL0R 0x020
#define TRCEVENTCTL1R 0x024
+#define TRCRSR 0x028
#define TRCSTALLCTLR 0x02C
#define TRCTSCTLR 0x030
#define TRCSYNCPR 0x034
@@ -49,6 +50,7 @@
#define TRCSEQRSTEVR 0x118
#define TRCSEQSTR 0x11C
#define TRCEXTINSELR 0x120
+#define TRCEXTINSELRn(n) (0x120 + (n * 4)) /* n = 0-3 */
#define TRCCNTRLDVRn(n) (0x140 + (n * 4)) /* n = 0-3 */
#define TRCCNTCTLRn(n) (0x150 + (n * 4)) /* n = 0-3 */
#define TRCCNTVRn(n) (0x160 + (n * 4)) /* n = 0-3 */
@@ -126,6 +128,8 @@
#define TRCCIDR2 0xFF8
#define TRCCIDR3 0xFFC
+#define TRCRSR_TA BIT(12)
+
/*
* System instructions to access ETM registers.
* See ETMv4.4 spec ARM IHI0064F section 4.3.6 System instructions
@@ -160,10 +164,22 @@
#define CASE_NOP(__unused, x) \
case (x): /* fall through */
+#define ETE_ONLY_SYSREG_LIST(op, val) \
+ CASE_##op((val), TRCRSR) \
+ CASE_##op((val), TRCEXTINSELRn(1)) \
+ CASE_##op((val), TRCEXTINSELRn(2)) \
+ CASE_##op((val), TRCEXTINSELRn(3))
+
/* List of registers accessible via System instructions */
-#define ETM_SYSREG_LIST(op, val) \
- CASE_##op((val), TRCPRGCTLR) \
+#define ETM4x_ONLY_SYSREG_LIST(op, val) \
CASE_##op((val), TRCPROCSELR) \
+ CASE_##op((val), TRCVDCTLR) \
+ CASE_##op((val), TRCVDSACCTLR) \
+ CASE_##op((val), TRCVDARCCTLR) \
+ CASE_##op((val), TRCOSLAR)
+
+#define ETM_COMMON_SYSREG_LIST(op, val) \
+ CASE_##op((val), TRCPRGCTLR) \
CASE_##op((val), TRCSTATR) \
CASE_##op((val), TRCCONFIGR) \
CASE_##op((val), TRCAUXCTLR) \
@@ -180,9 +196,6 @@
CASE_##op((val), TRCVIIECTLR) \
CASE_##op((val), TRCVISSCTLR) \
CASE_##op((val), TRCVIPCSSCTLR) \
- CASE_##op((val), TRCVDCTLR) \
- CASE_##op((val), TRCVDSACCTLR) \
- CASE_##op((val), TRCVDARCCTLR) \
CASE_##op((val), TRCSEQEVRn(0)) \
CASE_##op((val), TRCSEQEVRn(1)) \
CASE_##op((val), TRCSEQEVRn(2)) \
@@ -277,7 +290,6 @@
CASE_##op((val), TRCSSPCICRn(5)) \
CASE_##op((val), TRCSSPCICRn(6)) \
CASE_##op((val), TRCSSPCICRn(7)) \
- CASE_##op((val), TRCOSLAR) \
CASE_##op((val), TRCOSLSR) \
CASE_##op((val), TRCACVRn(0)) \
CASE_##op((val), TRCACVRn(1)) \
@@ -369,12 +381,38 @@
CASE_##op((val), TRCPIDR2) \
CASE_##op((val), TRCPIDR3)
-#define ETM4x_READ_SYSREG_CASES(res) ETM_SYSREG_LIST(READ, (res))
-#define ETM4x_WRITE_SYSREG_CASES(val) ETM_SYSREG_LIST(WRITE, (val))
+#define ETM4x_READ_SYSREG_CASES(res) \
+ ETM_COMMON_SYSREG_LIST(READ, (res)) \
+ ETM4x_ONLY_SYSREG_LIST(READ, (res))
+
+#define ETM4x_WRITE_SYSREG_CASES(val) \
+ ETM_COMMON_SYSREG_LIST(WRITE, (val)) \
+ ETM4x_ONLY_SYSREG_LIST(WRITE, (val))
+
+#define ETM_COMMON_SYSREG_LIST_CASES \
+ ETM_COMMON_SYSREG_LIST(NOP, __unused)
+
+#define ETM4x_ONLY_SYSREG_LIST_CASES \
+ ETM4x_ONLY_SYSREG_LIST(NOP, __unused)
+
+#define ETM4x_SYSREG_LIST_CASES \
+ ETM_COMMON_SYSREG_LIST_CASES \
+ ETM4x_ONLY_SYSREG_LIST(NOP, __unused)
-#define ETM4x_SYSREG_LIST_CASES ETM_SYSREG_LIST(NOP, __unused)
#define ETM4x_MMAP_LIST_CASES ETM_MMAP_LIST(NOP, __unused)
+/* ETE only supports system register access */
+#define ETE_READ_CASES(res) \
+ ETM_COMMON_SYSREG_LIST(READ, (res)) \
+ ETE_ONLY_SYSREG_LIST(READ, (res))
+
+#define ETE_WRITE_CASES(val) \
+ ETM_COMMON_SYSREG_LIST(WRITE, (val)) \
+ ETE_ONLY_SYSREG_LIST(WRITE, (val))
+
+#define ETE_ONLY_SYSREG_LIST_CASES \
+ ETE_ONLY_SYSREG_LIST(NOP, __unused)
+
#define read_etm4x_sysreg_offset(offset, _64bit) \
({ \
u64 __val; \
@@ -506,6 +544,20 @@
ETM_MODE_EXCL_USER)
/*
+ * TRCOSLSR.OSLM advertises the OS Lock model.
+ * OSLM[2:0] = TRCOSLSR[4:3,0]
+ *
+ * 0b000 - Trace OS Lock is not implemented.
+ * 0b010 - Trace OS Lock is implemented.
+ * 0b100 - Trace OS Lock is not implemented, unit is controlled by PE OS Lock.
+ */
+#define ETM_OSLOCK_NI 0b000
+#define ETM_OSLOCK_PRESENT 0b010
+#define ETM_OSLOCK_PE 0b100
+
+#define ETM_OSLSR_OSLM(oslsr) ((((oslsr) & GENMASK(4, 3)) >> 2) | (oslsr & 0x1))
+
+/*
* TRCDEVARCH Bit field definitions
* Bits[31:21] - ARCHITECT = Always Arm Ltd.
* * Bits[31:28] = 0x4
@@ -541,11 +593,14 @@
((ETM_DEVARCH_MAKE_ARCHID_ARCH_VER(major)) | ETM_DEVARCH_ARCHID_ARCH_PART(0xA13))
#define ETM_DEVARCH_ARCHID_ETMv4x ETM_DEVARCH_MAKE_ARCHID(0x4)
+#define ETM_DEVARCH_ARCHID_ETE ETM_DEVARCH_MAKE_ARCHID(0x5)
#define ETM_DEVARCH_ID_MASK \
(ETM_DEVARCH_ARCHITECT_MASK | ETM_DEVARCH_ARCHID_MASK | ETM_DEVARCH_PRESENT)
#define ETM_DEVARCH_ETMv4x_ARCH \
(ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETMv4x | ETM_DEVARCH_PRESENT)
+#define ETM_DEVARCH_ETE_ARCH \
+ (ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETE | ETM_DEVARCH_PRESENT)
#define TRCSTATR_IDLE_BIT 0
#define TRCSTATR_PMSTABLE_BIT 1
@@ -635,6 +690,8 @@
#define ETM_ARCH_MINOR_VERSION(arch) ((arch) & 0xfU)
#define ETM_ARCH_V4 ETM_ARCH_VERSION(4, 0)
+#define ETM_ARCH_ETE ETM_ARCH_VERSION(5, 0)
+
/* Interpretation of resource numbers change at ETM v4.3 architecture */
#define ETM_ARCH_V4_3 ETM_ARCH_VERSION(4, 3)
@@ -862,6 +919,7 @@ struct etmv4_save_state {
* @nooverflow: Indicate if overflow prevention is supported.
* @atbtrig: If the implementation can support ATB triggers
* @lpoverride: If the implementation can support low-power state over.
+ * @trfc: If the implementation supports Arm v8.4 trace filter controls.
* @config: structure holding configuration parameters.
* @save_state: State to be preserved across power loss
* @state_needs_restore: True when there is context to restore after PM exit
@@ -897,6 +955,7 @@ struct etmv4_drvdata {
u8 s_ex_level;
u8 ns_ex_level;
u8 q_support;
+ u8 os_lock_model;
bool sticky_enable;
bool boot_enable;
bool os_unlock;
@@ -912,6 +971,7 @@ struct etmv4_drvdata {
bool nooverflow;
bool atbtrig;
bool lpoverride;
+ bool trfc;
struct etmv4_config config;
struct etmv4_save_state *save_state;
bool state_needs_restore;
@@ -940,4 +1000,9 @@ void etm4_config_trace_mode(struct etmv4_config *config);
u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit);
void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit);
+
+static inline bool etm4x_is_ete(struct etmv4_drvdata *drvdata)
+{
+ return drvdata->arch >= ETM_ARCH_ETE;
+}
#endif
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 3629b7885aca..c594f45319fc 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -90,6 +90,12 @@ static void of_coresight_get_ports_legacy(const struct device_node *node,
struct of_endpoint endpoint;
int in = 0, out = 0;
+ /*
+ * Avoid warnings in of_graph_get_next_endpoint()
+ * if the device doesn't have any graph connections
+ */
+ if (!of_graph_is_present(node))
+ return;
do {
ep = of_graph_get_next_endpoint(node, ep);
if (!ep)
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index f5f654ea2994..ff1dd2092ac5 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -232,4 +232,7 @@ coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode);
void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev,
struct coresight_device *ect_csdev);
+void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev);
+struct coresight_device *coresight_get_percpu_sink(int cpu);
+
#endif
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
new file mode 100644
index 000000000000..176868496879
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -0,0 +1,1157 @@
+// 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.
+ *
+ * The AUX buffer handling is inspired from Arm SPE PMU driver.
+ *
+ * Copyright (C) 2020 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+#define DRVNAME "arm_trbe"
+
+#define pr_fmt(fmt) DRVNAME ": " fmt
+
+#include <asm/barrier.h>
+#include "coresight-trbe.h"
+
+#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
+
+/*
+ * A padding packet that will help the user space tools
+ * in skipping relevant sections in the captured trace
+ * data which could not be decoded. TRBE doesn't support
+ * formatting the trace data, unlike the legacy CoreSight
+ * sinks and thus we use ETE trace packets to pad the
+ * sections of the buffer.
+ */
+#define ETE_IGNORE_PACKET 0x70
+
+/*
+ * Minimum amount of meaningful trace will contain:
+ * A-Sync, Trace Info, Trace On, Address, Atom.
+ * This is about 44bytes of ETE trace. To be on
+ * the safer side, we assume 64bytes is the minimum
+ * space required for a meaningful session, before
+ * we hit a "WRAP" event.
+ */
+#define TRBE_TRACE_MIN_BUF_SIZE 64
+
+enum trbe_fault_action {
+ TRBE_FAULT_ACT_WRAP,
+ TRBE_FAULT_ACT_SPURIOUS,
+ TRBE_FAULT_ACT_FATAL,
+};
+
+struct trbe_buf {
+ /*
+ * Even though trbe_base represents vmap()
+ * mapped allocated buffer's start address,
+ * it's being as unsigned long for various
+ * arithmetic and comparision operations &
+ * also to be consistent with trbe_write &
+ * trbe_limit sibling pointers.
+ */
+ unsigned long trbe_base;
+ unsigned long trbe_limit;
+ unsigned long trbe_write;
+ int nr_pages;
+ void **pages;
+ bool snapshot;
+ struct trbe_cpudata *cpudata;
+};
+
+struct trbe_cpudata {
+ bool trbe_flag;
+ u64 trbe_align;
+ int cpu;
+ enum cs_mode mode;
+ struct trbe_buf *buf;
+ 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;
+};
+
+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_drain_buffer(void)
+{
+ tsb_csync();
+ dsb(nsh);
+}
+
+static void trbe_drain_and_disable_local(void)
+{
+ u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
+
+ trbe_drain_buffer();
+
+ /*
+ * Disable the TRBE without clearing LIMITPTR which
+ * might be required for fetching the buffer limits.
+ */
+ trblimitr &= ~TRBLIMITR_ENABLE;
+ write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
+ isb();
+}
+
+static void trbe_reset_local(void)
+{
+ trbe_drain_and_disable_local();
+ write_sysreg_s(0, SYS_TRBLIMITR_EL1);
+ write_sysreg_s(0, SYS_TRBPTR_EL1);
+ write_sysreg_s(0, SYS_TRBBASER_EL1);
+ write_sysreg_s(0, SYS_TRBSR_EL1);
+}
+
+static void trbe_stop_and_truncate_event(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+
+ /*
+ * We cannot proceed with the buffer collection and we
+ * do not have any data for the current session. The
+ * etm_perf driver expects to close out the aux_buffer
+ * at event_stop(). So disable the TRBE here and leave
+ * the update_buffer() to return a 0 size.
+ */
+ trbe_drain_and_disable_local();
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+ *this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL;
+}
+
+/*
+ * TRBE Buffer Management
+ *
+ * The TRBE buffer spans from the base pointer till the limit pointer. When enabled,
+ * it starts writing trace data from the write pointer onward till the limit pointer.
+ * When the write pointer reaches the address just before the limit pointer, it gets
+ * wrapped around again to the base pointer. This is called a TRBE wrap event, which
+ * generates a maintenance interrupt when operated in WRAP or FILL mode. This driver
+ * uses FILL mode, where the TRBE stops the trace collection at wrap event. The IRQ
+ * handler updates the AUX buffer and re-enables the TRBE with updated WRITE and
+ * LIMIT pointers.
+ *
+ * Wrap around with an IRQ
+ * ------ < ------ < ------- < ----- < -----
+ * | |
+ * ------ > ------ > ------- > ----- > -----
+ *
+ * +---------------+-----------------------+
+ * | | |
+ * +---------------+-----------------------+
+ * Base Pointer Write Pointer Limit Pointer
+ *
+ * The base and limit pointers always needs to be PAGE_SIZE aligned. But the write
+ * pointer can be aligned to the implementation defined TRBE trace buffer alignment
+ * as captured in trbe_cpudata->trbe_align.
+ *
+ *
+ * head tail wakeup
+ * +---------------------------------------+----- ~ ~ ------
+ * |$$$$$$$|################|$$$$$$$$$$$$$$| |
+ * +---------------------------------------+----- ~ ~ ------
+ * Base Pointer Write Pointer Limit Pointer
+ *
+ * The perf_output_handle indices (head, tail, wakeup) are monotonically increasing
+ * values which tracks all the driver writes and user reads from the perf auxiliary
+ * buffer. Generally [head..tail] is the area where the driver can write into unless
+ * the wakeup is behind the tail. Enabled TRBE buffer span needs to be adjusted and
+ * configured depending on the perf_output_handle indices, so that the driver does
+ * not override into areas in the perf auxiliary buffer which is being or yet to be
+ * consumed from the user space. The enabled TRBE buffer area is a moving subset of
+ * the allocated perf auxiliary buffer.
+ */
+static void trbe_pad_buf(struct perf_output_handle *handle, int len)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+ u64 head = PERF_IDX2OFF(handle->head, buf);
+
+ memset((void *)buf->trbe_base + head, ETE_IGNORE_PACKET, len);
+ if (!buf->snapshot)
+ perf_aux_output_skip(handle, len);
+}
+
+static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+
+ /*
+ * The ETE trace has alignment synchronization packets allowing
+ * the decoder to reset in case of an overflow or corruption.
+ * So we can use the entire buffer for the snapshot mode.
+ */
+ return buf->nr_pages * PAGE_SIZE;
+}
+
+/*
+ * TRBE Limit Calculation
+ *
+ * The following markers are used to illustrate various TRBE buffer situations.
+ *
+ * $$$$ - Data area, unconsumed captured trace data, not to be overridden
+ * #### - Free area, enabled, trace will be written
+ * %%%% - Free area, disabled, trace will not be written
+ * ==== - Free area, padded with ETE_IGNORE_PACKET, trace will be skipped
+ */
+static unsigned long __trbe_normal_offset(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+ struct trbe_cpudata *cpudata = buf->cpudata;
+ const u64 bufsize = buf->nr_pages * PAGE_SIZE;
+ u64 limit = bufsize;
+ u64 head, tail, wakeup;
+
+ head = PERF_IDX2OFF(handle->head, buf);
+
+ /*
+ * head
+ * ------->|
+ * |
+ * head TRBE align tail
+ * +----|-------|---------------|-------+
+ * |$$$$|=======|###############|$$$$$$$|
+ * +----|-------|---------------|-------+
+ * trbe_base trbe_base + nr_pages
+ *
+ * Perf aux buffer output head position can be misaligned depending on
+ * various factors including user space reads. In case misaligned, head
+ * needs to be aligned before TRBE can be configured. Pad the alignment
+ * gap with ETE_IGNORE_PACKET bytes that will be ignored by user tools
+ * and skip this section thus advancing the head.
+ */
+ if (!IS_ALIGNED(head, cpudata->trbe_align)) {
+ unsigned long delta = roundup(head, cpudata->trbe_align) - head;
+
+ delta = min(delta, handle->size);
+ trbe_pad_buf(handle, delta);
+ head = PERF_IDX2OFF(handle->head, buf);
+ }
+
+ /*
+ * head = tail (size = 0)
+ * +----|-------------------------------+
+ * |$$$$|$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ |
+ * +----|-------------------------------+
+ * trbe_base trbe_base + nr_pages
+ *
+ * Perf aux buffer does not have any space for the driver to write into.
+ * Just communicate trace truncation event to the user space by marking
+ * it with PERF_AUX_FLAG_TRUNCATED.
+ */
+ if (!handle->size) {
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+ return 0;
+ }
+
+ /* Compute the tail and wakeup indices now that we've aligned head */
+ tail = PERF_IDX2OFF(handle->head + handle->size, buf);
+ wakeup = PERF_IDX2OFF(handle->wakeup, buf);
+
+ /*
+ * Lets calculate the buffer area which TRBE could write into. There
+ * are three possible scenarios here. Limit needs to be aligned with
+ * PAGE_SIZE per the TRBE requirement. Always avoid clobbering the
+ * unconsumed data.
+ *
+ * 1) head < tail
+ *
+ * head tail
+ * +----|-----------------------|-------+
+ * |$$$$|#######################|$$$$$$$|
+ * +----|-----------------------|-------+
+ * trbe_base limit trbe_base + nr_pages
+ *
+ * TRBE could write into [head..tail] area. Unless the tail is right at
+ * the end of the buffer, neither an wrap around nor an IRQ is expected
+ * while being enabled.
+ *
+ * 2) head == tail
+ *
+ * head = tail (size > 0)
+ * +----|-------------------------------+
+ * |%%%%|###############################|
+ * +----|-------------------------------+
+ * trbe_base limit = trbe_base + nr_pages
+ *
+ * TRBE should just write into [head..base + nr_pages] area even though
+ * the entire buffer is empty. Reason being, when the trace reaches the
+ * end of the buffer, it will just wrap around with an IRQ giving an
+ * opportunity to reconfigure the buffer.
+ *
+ * 3) tail < head
+ *
+ * tail head
+ * +----|-----------------------|-------+
+ * |%%%%|$$$$$$$$$$$$$$$$$$$$$$$|#######|
+ * +----|-----------------------|-------+
+ * trbe_base limit = trbe_base + nr_pages
+ *
+ * TRBE should just write into [head..base + nr_pages] area even though
+ * the [trbe_base..tail] is also empty. Reason being, when the trace
+ * reaches the end of the buffer, it will just wrap around with an IRQ
+ * giving an opportunity to reconfigure the buffer.
+ */
+ if (head < tail)
+ limit = round_down(tail, PAGE_SIZE);
+
+ /*
+ * Wakeup may be arbitrarily far into the future. If it's not in the
+ * current generation, either we'll wrap before hitting it, or it's
+ * in the past and has been handled already.
+ *
+ * If there's a wakeup before we wrap, arrange to be woken up by the
+ * page boundary following it. Keep the tail boundary if that's lower.
+ *
+ * head wakeup tail
+ * +----|---------------|-------|-------+
+ * |$$$$|###############|%%%%%%%|$$$$$$$|
+ * +----|---------------|-------|-------+
+ * trbe_base limit trbe_base + nr_pages
+ */
+ if (handle->wakeup < (handle->head + handle->size) && head <= wakeup)
+ limit = min(limit, round_up(wakeup, PAGE_SIZE));
+
+ /*
+ * There are two situation when this can happen i.e limit is before
+ * the head and hence TRBE cannot be configured.
+ *
+ * 1) head < tail (aligned down with PAGE_SIZE) and also they are both
+ * within the same PAGE size range.
+ *
+ * PAGE_SIZE
+ * |----------------------|
+ *
+ * limit head tail
+ * +------------|------|--------|-------+
+ * |$$$$$$$$$$$$$$$$$$$|========|$$$$$$$|
+ * +------------|------|--------|-------+
+ * trbe_base trbe_base + nr_pages
+ *
+ * 2) head < wakeup (aligned up with PAGE_SIZE) < tail and also both
+ * head and wakeup are within same PAGE size range.
+ *
+ * PAGE_SIZE
+ * |----------------------|
+ *
+ * limit head wakeup tail
+ * +----|------|-------|--------|-------+
+ * |$$$$$$$$$$$|=======|========|$$$$$$$|
+ * +----|------|-------|--------|-------+
+ * trbe_base trbe_base + nr_pages
+ */
+ 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 trbe_normal_offset(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = perf_get_aux(handle);
+ u64 limit = __trbe_normal_offset(handle);
+ u64 head = PERF_IDX2OFF(handle->head, buf);
+
+ /*
+ * If the head is too close to the limit and we don't
+ * have space for a meaningful run, we rather pad it
+ * and start fresh.
+ */
+ if (limit && (limit - head < TRBE_TRACE_MIN_BUF_SIZE)) {
+ trbe_pad_buf(handle, limit - head);
+ limit = __trbe_normal_offset(handle);
+ }
+ return limit;
+}
+
+static unsigned long compute_trbe_buffer_limit(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+ unsigned long offset;
+
+ if (buf->snapshot)
+ offset = trbe_snapshot_offset(handle);
+ else
+ offset = trbe_normal_offset(handle);
+ return buf->trbe_base + offset;
+}
+
+static void clr_trbe_status(void)
+{
+ u64 trbsr = read_sysreg_s(SYS_TRBSR_EL1);
+
+ WARN_ON(is_trbe_enabled());
+ trbsr &= ~TRBSR_IRQ;
+ trbsr &= ~TRBSR_TRG;
+ trbsr &= ~TRBSR_WRAP;
+ trbsr &= ~(TRBSR_EC_MASK << TRBSR_EC_SHIFT);
+ trbsr &= ~(TRBSR_BSC_MASK << TRBSR_BSC_SHIFT);
+ trbsr &= ~TRBSR_STOP;
+ write_sysreg_s(trbsr, SYS_TRBSR_EL1);
+}
+
+static void set_trbe_limit_pointer_enabled(unsigned long addr)
+{
+ u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
+
+ WARN_ON(!IS_ALIGNED(addr, (1UL << TRBLIMITR_LIMIT_SHIFT)));
+ WARN_ON(!IS_ALIGNED(addr, PAGE_SIZE));
+
+ trblimitr &= ~TRBLIMITR_NVM;
+ trblimitr &= ~(TRBLIMITR_FILL_MODE_MASK << TRBLIMITR_FILL_MODE_SHIFT);
+ trblimitr &= ~(TRBLIMITR_TRIG_MODE_MASK << TRBLIMITR_TRIG_MODE_SHIFT);
+ trblimitr &= ~(TRBLIMITR_LIMIT_MASK << TRBLIMITR_LIMIT_SHIFT);
+
+ /*
+ * Fill trace buffer mode is used here while configuring the
+ * TRBE for trace capture. In this particular mode, the trace
+ * collection is stopped and a maintenance interrupt is raised
+ * when the current write pointer wraps. This pause in trace
+ * collection gives the software an opportunity to capture the
+ * trace data in the interrupt handler, before reconfiguring
+ * the TRBE.
+ */
+ trblimitr |= (TRBE_FILL_MODE_FILL & TRBLIMITR_FILL_MODE_MASK) << TRBLIMITR_FILL_MODE_SHIFT;
+
+ /*
+ * Trigger mode is not used here while configuring the TRBE for
+ * the trace capture. Hence just keep this in the ignore mode.
+ */
+ trblimitr |= (TRBE_TRIG_MODE_IGNORE & TRBLIMITR_TRIG_MODE_MASK) <<
+ TRBLIMITR_TRIG_MODE_SHIFT;
+ trblimitr |= (addr & PAGE_MASK);
+
+ trblimitr |= TRBLIMITR_ENABLE;
+ write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1);
+
+ /* Synchronize the TRBE enable event */
+ isb();
+}
+
+static void trbe_enable_hw(struct trbe_buf *buf)
+{
+ WARN_ON(buf->trbe_write < buf->trbe_base);
+ WARN_ON(buf->trbe_write >= buf->trbe_limit);
+ set_trbe_disabled();
+ isb();
+ clr_trbe_status();
+ set_trbe_base_pointer(buf->trbe_base);
+ set_trbe_write_pointer(buf->trbe_write);
+
+ /*
+ * Synchronize all the register updates
+ * till now before enabling the TRBE.
+ */
+ isb();
+ set_trbe_limit_pointer_enabled(buf->trbe_limit);
+}
+
+static enum trbe_fault_action trbe_get_fault_act(u64 trbsr)
+{
+ int ec = get_trbe_ec(trbsr);
+ int bsc = get_trbe_bsc(trbsr);
+
+ WARN_ON(is_trbe_running(trbsr));
+ if (is_trbe_trg(trbsr) || is_trbe_abort(trbsr))
+ 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(trbsr) && (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 void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
+ struct perf_event *event, void **pages,
+ int nr_pages, bool snapshot)
+{
+ struct trbe_buf *buf;
+ struct page **pglist;
+ int i;
+
+ /*
+ * TRBE LIMIT and TRBE WRITE pointers must be page aligned. But with
+ * just a single page, there would not be any room left while writing
+ * into a partially filled TRBE buffer after the page size alignment.
+ * Hence restrict the minimum buffer size as two pages.
+ */
+ if (nr_pages < 2)
+ return NULL;
+
+ buf = kzalloc_node(sizeof(*buf), GFP_KERNEL, trbe_alloc_node(event));
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ pglist = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL);
+ if (!pglist) {
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for (i = 0; i < nr_pages; i++)
+ pglist[i] = virt_to_page(pages[i]);
+
+ buf->trbe_base = (unsigned long)vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
+ if (!buf->trbe_base) {
+ kfree(pglist);
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+ buf->trbe_limit = buf->trbe_base + nr_pages * PAGE_SIZE;
+ buf->trbe_write = buf->trbe_base;
+ buf->snapshot = snapshot;
+ buf->nr_pages = nr_pages;
+ buf->pages = pages;
+ kfree(pglist);
+ return buf;
+}
+
+static void arm_trbe_free_buffer(void *config)
+{
+ struct trbe_buf *buf = config;
+
+ vunmap((void *)buf->trbe_base);
+ kfree(buf);
+}
+
+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_buf *buf = config;
+ enum trbe_fault_action act;
+ unsigned long size, offset;
+ unsigned long write, base, status;
+ unsigned long flags;
+
+ WARN_ON(buf->cpudata != cpudata);
+ WARN_ON(cpudata->cpu != smp_processor_id());
+ WARN_ON(cpudata->drvdata != drvdata);
+ if (cpudata->mode != CS_MODE_PERF)
+ return 0;
+
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW);
+
+ /*
+ * We are about to disable the TRBE. And this could in turn
+ * fill up the buffer triggering, an IRQ. This could be consumed
+ * by the PE asynchronously, causing a race here against
+ * the IRQ handler in closing out the handle. So, let us
+ * make sure the IRQ can't trigger while we are collecting
+ * the buffer. We also make sure that a WRAP event is handled
+ * accordingly.
+ */
+ local_irq_save(flags);
+
+ /*
+ * If the TRBE was disabled due to lack of space in the AUX buffer or a
+ * spurious fault, the driver leaves it disabled, truncating the buffer.
+ * Since the etm_perf driver expects to close out the AUX buffer, the
+ * driver skips it. Thus, just pass in 0 size here to indicate that the
+ * buffer was truncated.
+ */
+ if (!is_trbe_enabled()) {
+ size = 0;
+ goto done;
+ }
+ /*
+ * perf handle structure needs to be shared with the TRBE IRQ handler for
+ * capturing trace data and restarting the handle. There is a probability
+ * of an undefined reference based crash when etm event is being stopped
+ * while a TRBE IRQ also getting processed. This happens due the release
+ * of perf handle via perf_aux_output_end() in etm_event_stop(). Stopping
+ * the TRBE here will ensure that no IRQ could be generated when the perf
+ * handle gets freed in etm_event_stop().
+ */
+ trbe_drain_and_disable_local();
+ write = get_trbe_write_pointer();
+ base = get_trbe_base_pointer();
+
+ /* Check if there is a pending interrupt and handle it here */
+ status = read_sysreg_s(SYS_TRBSR_EL1);
+ if (is_trbe_irq(status)) {
+
+ /*
+ * Now that we are handling the IRQ here, clear the IRQ
+ * from the status, to let the irq handler know that it
+ * is taken care of.
+ */
+ clr_trbe_irq();
+ isb();
+
+ act = trbe_get_fault_act(status);
+ /*
+ * If this was not due to a WRAP event, we have some
+ * errors and as such buffer is empty.
+ */
+ if (act != TRBE_FAULT_ACT_WRAP) {
+ size = 0;
+ goto done;
+ }
+
+ /*
+ * Otherwise, the buffer is full and the write pointer
+ * has reached base. Adjust this back to the Limit pointer
+ * for correct size. Also, mark the buffer truncated.
+ */
+ write = get_trbe_limit_pointer();
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+ }
+
+ offset = write - base;
+ if (WARN_ON_ONCE(offset < PERF_IDX2OFF(handle->head, buf)))
+ size = 0;
+ else
+ size = offset - PERF_IDX2OFF(handle->head, buf);
+
+done:
+ local_irq_restore(flags);
+
+ if (buf->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_buf *buf = etm_perf_sink_config(handle);
+
+ WARN_ON(cpudata->cpu != smp_processor_id());
+ WARN_ON(cpudata->drvdata != drvdata);
+ if (mode != CS_MODE_PERF)
+ return -EINVAL;
+
+ *this_cpu_ptr(drvdata->handle) = handle;
+ cpudata->buf = buf;
+ cpudata->mode = mode;
+ buf->cpudata = cpudata;
+ buf->trbe_limit = compute_trbe_buffer_limit(handle);
+ buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf);
+ if (buf->trbe_limit == buf->trbe_base) {
+ trbe_stop_and_truncate_event(handle);
+ return 0;
+ }
+ trbe_enable_hw(buf);
+ 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_buf *buf = cpudata->buf;
+
+ WARN_ON(buf->cpudata != cpudata);
+ WARN_ON(cpudata->cpu != smp_processor_id());
+ WARN_ON(cpudata->drvdata != drvdata);
+ if (cpudata->mode != CS_MODE_PERF)
+ return -EINVAL;
+
+ trbe_drain_and_disable_local();
+ buf->cpudata = NULL;
+ cpudata->buf = NULL;
+ cpudata->mode = CS_MODE_DISABLED;
+ return 0;
+}
+
+static void trbe_handle_spurious(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+
+ buf->trbe_limit = compute_trbe_buffer_limit(handle);
+ buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf);
+ if (buf->trbe_limit == buf->trbe_base) {
+ trbe_drain_and_disable_local();
+ return;
+ }
+ trbe_enable_hw(buf);
+}
+
+static void trbe_handle_overflow(struct perf_output_handle *handle)
+{
+ struct perf_event *event = handle->event;
+ struct trbe_buf *buf = 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, buf);
+ if (buf->snapshot)
+ handle->head += size;
+
+ /*
+ * Mark the buffer as truncated, as we have stopped the trace
+ * collection upon the WRAP event, without stopping the source.
+ */
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW |
+ PERF_AUX_FLAG_TRUNCATED);
+ perf_aux_output_end(handle, size);
+ event_data = perf_aux_output_begin(handle, event);
+ if (!event_data) {
+ /*
+ * We are unable to restart the trace collection,
+ * thus leave the TRBE disabled. The etm-perf driver
+ * is able to detect this with a disconnected handle
+ * (handle->event = NULL).
+ */
+ trbe_drain_and_disable_local();
+ *this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL;
+ return;
+ }
+ buf->trbe_limit = compute_trbe_buffer_limit(handle);
+ buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf);
+ if (buf->trbe_limit == buf->trbe_base) {
+ trbe_stop_and_truncate_event(handle);
+ return;
+ }
+ *this_cpu_ptr(buf->cpudata->drvdata->handle) = handle;
+ trbe_enable_hw(buf);
+}
+
+static bool is_perf_trbe(struct perf_output_handle *handle)
+{
+ struct trbe_buf *buf = etm_perf_sink_config(handle);
+ struct trbe_cpudata *cpudata = buf->cpudata;
+ struct trbe_drvdata *drvdata = cpudata->drvdata;
+ int cpu = smp_processor_id();
+
+ WARN_ON(buf->trbe_base != get_trbe_base_pointer());
+ WARN_ON(buf->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 irqreturn_t arm_trbe_irq_handler(int irq, void *dev)
+{
+ struct perf_output_handle **handle_ptr = dev;
+ struct perf_output_handle *handle = *handle_ptr;
+ enum trbe_fault_action act;
+ u64 status;
+
+ /*
+ * Ensure the trace is visible to the CPUs and
+ * any external aborts have been resolved.
+ */
+ trbe_drain_and_disable_local();
+
+ status = read_sysreg_s(SYS_TRBSR_EL1);
+ /*
+ * If the pending IRQ was handled by update_buffer callback
+ * we have nothing to do here.
+ */
+ if (!is_trbe_irq(status))
+ return IRQ_NONE;
+
+ clr_trbe_irq();
+ isb();
+
+ if (WARN_ON_ONCE(!handle) || !perf_get_aux(handle))
+ return IRQ_NONE;
+
+ if (!is_perf_trbe(handle))
+ return IRQ_NONE;
+
+ /*
+ * Ensure perf callbacks have completed, which may disable
+ * the trace buffer in response to a TRUNCATION flag.
+ */
+ irq_work_run();
+
+ act = trbe_get_fault_act(status);
+ 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_stop_and_truncate_event(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 align_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct trbe_cpudata *cpudata = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%llx\n", cpudata->trbe_align);
+}
+static DEVICE_ATTR_RO(align);
+
+static ssize_t flag_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_flag);
+}
+static DEVICE_ATTR_RO(flag);
+
+static struct attribute *arm_trbe_attrs[] = {
+ &dev_attr_align.attr,
+ &dev_attr_flag.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_enable_cpu(void *info)
+{
+ struct trbe_drvdata *drvdata = info;
+
+ trbe_reset_local();
+ enable_percpu_irq(drvdata->irq, IRQ_TYPE_NONE);
+}
+
+static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cpu)
+{
+ struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
+ struct coresight_device *trbe_csdev = coresight_get_percpu_sink(cpu);
+ struct coresight_desc desc = { 0 };
+ struct device *dev;
+
+ if (WARN_ON(trbe_csdev))
+ return;
+
+ dev = &cpudata->drvdata->pdev->dev;
+ desc.name = devm_kasprintf(dev, GFP_KERNEL, "trbe%d", cpu);
+ if (!desc.name)
+ goto cpu_clear;
+
+ desc.type = CORESIGHT_DEV_TYPE_SINK;
+ desc.subtype.sink_subtype = 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;
+ trbe_csdev = coresight_register(&desc);
+ if (IS_ERR(trbe_csdev))
+ goto cpu_clear;
+
+ dev_set_drvdata(&trbe_csdev->dev, cpudata);
+ coresight_set_percpu_sink(cpu, trbe_csdev);
+ return;
+cpu_clear:
+ cpumask_clear_cpu(cpu, &drvdata->supported_cpus);
+}
+
+static void arm_trbe_probe_cpu(void *info)
+{
+ struct trbe_drvdata *drvdata = info;
+ int cpu = smp_processor_id();
+ struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
+ u64 trbidr;
+
+ if (WARN_ON(!cpudata))
+ goto cpu_clear;
+
+ if (!is_trbe_available()) {
+ pr_err("TRBE is not implemented on cpu %d\n", cpu);
+ goto cpu_clear;
+ }
+
+ trbidr = read_sysreg_s(SYS_TRBIDR_EL1);
+ if (!is_trbe_programmable(trbidr)) {
+ pr_err("TRBE is owned in higher exception level on cpu %d\n", cpu);
+ goto cpu_clear;
+ }
+
+ cpudata->trbe_align = 1ULL << get_trbe_address_align(trbidr);
+ if (cpudata->trbe_align > SZ_2K) {
+ pr_err("Unsupported alignment on cpu %d\n", cpu);
+ goto cpu_clear;
+ }
+ cpudata->trbe_flag = get_trbe_flag_update(trbidr);
+ cpudata->cpu = cpu;
+ cpudata->drvdata = drvdata;
+ return;
+cpu_clear:
+ cpumask_clear_cpu(cpu, &drvdata->supported_cpus);
+}
+
+static void arm_trbe_remove_coresight_cpu(void *info)
+{
+ int cpu = smp_processor_id();
+ struct trbe_drvdata *drvdata = info;
+ struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
+ struct coresight_device *trbe_csdev = coresight_get_percpu_sink(cpu);
+
+ disable_percpu_irq(drvdata->irq);
+ trbe_reset_local();
+ if (trbe_csdev) {
+ coresight_unregister(trbe_csdev);
+ cpudata->drvdata = NULL;
+ coresight_set_percpu_sink(cpu, NULL);
+ }
+}
+
+static int arm_trbe_probe_coresight(struct trbe_drvdata *drvdata)
+{
+ int cpu;
+
+ drvdata->cpudata = alloc_percpu(typeof(*drvdata->cpudata));
+ if (!drvdata->cpudata)
+ return -ENOMEM;
+
+ for_each_cpu(cpu, &drvdata->supported_cpus) {
+ smp_call_function_single(cpu, arm_trbe_probe_cpu, drvdata, 1);
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))
+ arm_trbe_register_coresight_cpu(drvdata, cpu);
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))
+ smp_call_function_single(cpu, arm_trbe_enable_cpu, drvdata, 1);
+ }
+ return 0;
+}
+
+static int arm_trbe_remove_coresight(struct trbe_drvdata *drvdata)
+{
+ int cpu;
+
+ for_each_cpu(cpu, &drvdata->supported_cpus)
+ smp_call_function_single(cpu, arm_trbe_remove_coresight_cpu, drvdata, 1);
+ 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);
+
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) {
+
+ /*
+ * If this CPU was not probed for TRBE,
+ * initialize it now.
+ */
+ if (!coresight_get_percpu_sink(cpu)) {
+ arm_trbe_probe_cpu(drvdata);
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))
+ arm_trbe_register_coresight_cpu(drvdata, cpu);
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))
+ arm_trbe_enable_cpu(drvdata);
+ } else {
+ arm_trbe_enable_cpu(drvdata);
+ }
+ }
+ 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);
+
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) {
+ 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;
+ int ret;
+
+ trbe_online = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRVNAME,
+ arm_trbe_cpu_startup, arm_trbe_cpu_teardown);
+ if (trbe_online < 0)
+ return trbe_online;
+
+ ret = cpuhp_state_add_instance(trbe_online, &drvdata->hotplug_node);
+ if (ret) {
+ cpuhp_remove_multi_state(trbe_online);
+ return ret;
+ }
+ 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)
+{
+ int ret;
+
+ drvdata->irq = platform_get_irq(pdev, 0);
+ if (drvdata->irq < 0) {
+ pr_err("IRQ not found for the platform device\n");
+ return drvdata->irq;
+ }
+
+ 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(struct perf_output_handle *);
+ if (!drvdata->handle)
+ return -ENOMEM;
+
+ ret = request_percpu_irq(drvdata->irq, arm_trbe_irq_handler, DRVNAME, drvdata->handle);
+ if (ret) {
+ free_percpu(drvdata->handle);
+ return ret;
+ }
+ 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 (!drvdata)
+ return -ENOMEM;
+
+ pdata = coresight_get_platform_data(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+
+ dev_set_drvdata(dev, drvdata);
+ dev->platform_data = pdata;
+ drvdata->pdev = pdev;
+ ret = arm_trbe_probe_irq(pdev, drvdata);
+ if (ret)
+ return ret;
+
+ 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);
+ return ret;
+}
+
+static int arm_trbe_device_remove(struct platform_device *pdev)
+{
+ struct trbe_drvdata *drvdata = platform_get_drvdata(pdev);
+
+ arm_trbe_remove_cpuhp(drvdata);
+ arm_trbe_remove_coresight(drvdata);
+ arm_trbe_remove_irq(drvdata);
+ return 0;
+}
+
+static const struct of_device_id arm_trbe_of_match[] = {
+ { .compatible = "arm,trace-buffer-extension"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, arm_trbe_of_match);
+
+static struct platform_driver arm_trbe_driver = {
+ .driver = {
+ .name = DRVNAME,
+ .of_match_table = of_match_ptr(arm_trbe_of_match),
+ .suppress_bind_attrs = true,
+ },
+ .probe = arm_trbe_device_probe,
+ .remove = arm_trbe_device_remove,
+};
+
+static int __init arm_trbe_init(void)
+{
+ int ret;
+
+ if (arm64_kernel_unmapped_at_el0()) {
+ pr_err("TRBE wouldn't work if kernel gets unmapped at EL0\n");
+ return -EOPNOTSUPP;
+ }
+
+ ret = platform_driver_register(&arm_trbe_driver);
+ if (!ret)
+ return 0;
+
+ pr_err("Error registering %s platform driver\n", DRVNAME);
+ return ret;
+}
+
+static void __exit arm_trbe_exit(void)
+{
+ platform_driver_unregister(&arm_trbe_driver);
+}
+module_init(arm_trbe_init);
+module_exit(arm_trbe_exit);
+
+MODULE_AUTHOR("Anshuman Khandual <anshuman.khandual@arm.com>");
+MODULE_DESCRIPTION("Arm Trace Buffer Extension (TRBE) driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/hwtracing/coresight/coresight-trbe.h b/drivers/hwtracing/coresight/coresight-trbe.h
new file mode 100644
index 000000000000..abf3e36082f0
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-trbe.h
@@ -0,0 +1,152 @@
+/* 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);
+ unsigned int trbe = cpuid_feature_extract_unsigned_field(aa64dfr0, ID_AA64DFR0_TRBE_SHIFT);
+
+ return trbe >= 0b0001;
+}
+
+static inline bool is_trbe_enabled(void)
+{
+ u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1);
+
+ return trblimitr & TRBLIMITR_ENABLE;
+}
+
+#define TRBE_EC_OTHERS 0
+#define TRBE_EC_STAGE1_ABORT 36
+#define TRBE_EC_STAGE2_ABORT 37
+
+static inline int get_trbe_ec(u64 trbsr)
+{
+ return (trbsr >> TRBSR_EC_SHIFT) & TRBSR_EC_MASK;
+}
+
+#define TRBE_BSC_NOT_STOPPED 0
+#define TRBE_BSC_FILLED 1
+#define TRBE_BSC_TRIGGERED 2
+
+static inline int get_trbe_bsc(u64 trbsr)
+{
+ return (trbsr >> TRBSR_BSC_SHIFT) & TRBSR_BSC_MASK;
+}
+
+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 bool is_trbe_irq(u64 trbsr)
+{
+ return trbsr & TRBSR_IRQ;
+}
+
+static inline bool is_trbe_trg(u64 trbsr)
+{
+ return trbsr & TRBSR_TRG;
+}
+
+static inline bool is_trbe_wrap(u64 trbsr)
+{
+ return trbsr & TRBSR_WRAP;
+}
+
+static inline bool is_trbe_abort(u64 trbsr)
+{
+ return trbsr & TRBSR_ABORT;
+}
+
+static inline bool is_trbe_running(u64 trbsr)
+{
+ return !(trbsr & TRBSR_STOP);
+}
+
+#define TRBE_TRIG_MODE_STOP 0
+#define TRBE_TRIG_MODE_IRQ 1
+#define TRBE_TRIG_MODE_IGNORE 3
+
+#define TRBE_FILL_MODE_FILL 0
+#define TRBE_FILL_MODE_WRAP 1
+#define TRBE_FILL_MODE_CIRCULAR_BUFFER 3
+
+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 bool get_trbe_flag_update(u64 trbidr)
+{
+ return trbidr & TRBIDR_FLAG;
+}
+
+static inline bool is_trbe_programmable(u64 trbidr)
+{
+ return !(trbidr & TRBIDR_PROG);
+}
+
+static inline int get_trbe_address_align(u64 trbidr)
+{
+ return (trbidr >> TRBIDR_ALIGN_SHIFT) & TRBIDR_ALIGN_MASK;
+}
+
+static inline unsigned long get_trbe_write_pointer(void)
+{
+ return read_sysreg_s(SYS_TRBPTR_EL1);
+}
+
+static inline void set_trbe_write_pointer(unsigned long addr)
+{
+ WARN_ON(is_trbe_enabled());
+ 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 addr = trblimitr & (TRBLIMITR_LIMIT_MASK << TRBLIMITR_LIMIT_SHIFT);
+
+ WARN_ON(!IS_ALIGNED(addr, PAGE_SIZE));
+ return addr;
+}
+
+static inline unsigned long get_trbe_base_pointer(void)
+{
+ u64 trbbaser = read_sysreg_s(SYS_TRBBASER_EL1);
+ unsigned long addr = trbbaser & (TRBBASER_BASE_MASK << TRBBASER_BASE_SHIFT);
+
+ WARN_ON(!IS_ALIGNED(addr, PAGE_SIZE));
+ return addr;
+}
+
+static inline void set_trbe_base_pointer(unsigned long addr)
+{
+ WARN_ON(is_trbe_enabled());
+ WARN_ON(!IS_ALIGNED(addr, (1UL << TRBBASER_BASE_SHIFT)));
+ WARN_ON(!IS_ALIGNED(addr, PAGE_SIZE));
+ write_sysreg_s(addr, SYS_TRBBASER_EL1);
+}