If the CPU implements Arm v8.4 Trace filter controls (FEAT_TRF),
move the ETM to trace prohibited region using TRFCR, while disabling.
Cc: Mathieu Poirier <mathieu.poir...@linaro.org>
Cc: Mike Leach <mike.le...@linaro.org>
Cc: Anshuman Khandual <anshuman.khand...@arm.com>
Reviewed-by: Mike Leach <mike.le...@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
.../coresight/coresight-etm4x-core.c | 21 +++++++++++++++++--
drivers/hwtracing/coresight/coresight-etm4x.h | 2 ++
2 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c
b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 15016f757828..00297906669c 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>
@@ -654,6 +655,7 @@ 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;
@@ -676,6 +678,16 @@ static void etm4_disable_hw(void *info)
/* EN, bit[0] Trace unit enable bit */
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,
@@ -683,12 +695,16 @@ static void etm4_disable_hw(void *info)
*/
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++) {
@@ -873,7 +889,7 @@ 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 +897,7 @@ 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
@@ -1082,7 +1099,7 @@ 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)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h
b/drivers/hwtracing/coresight/coresight-etm4x.h
index 0af60571aa23..f6478ef642bf 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -862,6 +862,7 @@ 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
@@ -912,6 +913,7 @@ 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;
--
2.24.1
