[PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

Yeoreum Yun
2026-04-15T16:55:41Z

The purpose of TRCSSCSRn register is to show status of
the corresponding Single-shot Comparator Control and input supports.
That means writable field's purpose for reset or restore from idle status
not for configuration.

Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps
and rename it to ss_smp.

This includes remove TRCSSCRn from configurable item and
remove saving in etm4_disable_hw().

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
.../hwtracing/coresight/coresight-etm4x-cfg.c | 1 -
.../coresight/coresight-etm4x-core.c | 19 ++++++-------------
.../coresight/coresight-etm4x-sysfs.c | 7 ++-----
drivers/hwtracing/coresight/coresight-etm4x.h | 7 ++++++-
4 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
index c302072b293a..d14d7c8a23e5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
@@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
off_mask = (offset & GENMASK(11, 5));
do {
CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
- CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
} while (0);
} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index b2b092a76eb5..f55338a4989d 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
const struct etmv4_caps *caps = &drvdata->caps;

return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
- (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
+ (caps->ss_cmp[n] & TRCSSCSRn_PC);
}

u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
@@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));

for (i = 0; i < caps->nr_ss_cmp; i++) {
- /* always clear status bit on restart if using single-shot */
- if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
- config->ss_status[i] &= ~TRCSSCSRn_STATUS;
etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
- etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
+ /* always clear status and pending bits on restart if using single-shot */
+ etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));
if (etm4x_sspcicrn_present(drvdata, i))
etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
}
@@ -1055,12 +1053,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)

etm4_disable_trace_unit(drvdata);

- /* read the status of the single shot comparators */
- for (i = 0; i < caps->nr_ss_cmp; i++) {
- config->ss_status[i] =
- etm4x_relaxed_read32(csa, TRCSSCSRn(i));
- }
-
/* read back the current counter values */
for (i = 0; i < caps->nr_cntr; i++) {
config->cntr_val[i] =
@@ -1503,8 +1495,9 @@ static void etm4_init_arch_data(void *info)
*/
caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
for (i = 0; i < caps->nr_ss_cmp; i++) {
- drvdata->config.ss_status[i] =
- etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+ caps->ss_cmp[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+ caps->ss_cmp[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
+ TRCSSCSRn_DA | TRCSSCSRn_INST);
}
/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
caps->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 8bd28e71d4c9..5e26c2ec8f7b 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1829,8 +1829,6 @@ static ssize_t sshot_ctrl_store(struct device *dev,
raw_spin_lock(&drvdata->spinlock);
idx = config->ss_idx;
config->ss_ctrl[idx] = FIELD_PREP(TRCSSCCRn_SAC_ARC_RST_MASK, val);
- /* must clear bit 31 in related status register on programming */
- config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
raw_spin_unlock(&drvdata->spinlock);
return size;
}
@@ -1841,10 +1839,11 @@ static ssize_t sshot_status_show(struct device *dev,
{
unsigned long val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ const struct etmv4_caps *caps = &drvdata->caps;
struct etmv4_config *config = &drvdata->config;

raw_spin_lock(&drvdata->spinlock);
- val = config->ss_status[config->ss_idx];
+ val = caps->ss_cmp[config->ss_idx];
raw_spin_unlock(&drvdata->spinlock);
return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
}
@@ -1879,8 +1878,6 @@ static ssize_t sshot_pe_ctrl_store(struct device *dev,
raw_spin_lock(&drvdata->spinlock);
idx = config->ss_idx;
config->ss_pe_cmp[idx] = FIELD_PREP(TRCSSPCICRn_PC_MASK, val);
- /* must clear bit 31 in related status register on programming */
- config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
raw_spin_unlock(&drvdata->spinlock);
return size;
}
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 8168676f2945..db56c4414873 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -213,6 +213,7 @@
#define TRCACATRn_EXLEVEL_MASK GENMASK(14, 8)

#define TRCSSCSRn_STATUS BIT(31)
+#define TRCSSCSRn_PENDING BIT(30)
#define TRCSSCCRn_SAC_ARC_RST_MASK GENMASK(24, 0)

#define TRCSSPCICRn_PC_MASK GENMASK(7, 0)
@@ -729,6 +730,9 @@ static inline u32 etm4_res_sel_pair(u8 res_sel_idx)
#define ETM_DEFAULT_ADDR_COMP 0

#define TRCSSCSRn_PC BIT(3)
+#define TRCSSCSRn_DV BIT(2)
+#define TRCSSCSRn_DA BIT(1)
+#define TRCSSCSRn_INST BIT(0)

/* PowerDown Control Register bits */
#define TRCPDCR_PU BIT(3)
@@ -861,6 +865,7 @@ enum etm_impdef_type {
* @lpoverride: If the implementation can support low-power state over.
* @skip_power_up: Indicates if an implementation can skip powering up
* the trace unit.
+ * @ss_cmp: Indicates supported single-shot comparators.
*/
struct etmv4_caps {
u8 nr_pe;
@@ -899,6 +904,7 @@ struct etmv4_caps {
bool atbtrig : 1;
bool lpoverride : 1;
bool skip_power_up : 1;
+ u32 ss_cmp[ETM_MAX_SS_CMP];
};

/**
@@ -977,7 +983,6 @@ struct etmv4_config {
u32 res_ctrl[ETM_MAX_RES_SEL]; /* TRCRSCTLRn */
u8 ss_idx;
u32 ss_ctrl[ETM_MAX_SS_CMP];
- u32 ss_status[ETM_MAX_SS_CMP];
u32 ss_pe_cmp[ETM_MAX_SS_CMP];
u8 addr_idx;
u64 addr_val[ETM_MAX_SINGLE_ADDR_CMP];
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}