[PATCH v2 2/5] coresight: etm4x: exclude ss_status from drvdata->config

Yeoreum Yun
2026-04-10T07:43:29Z

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.
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 -
.../hwtracing/coresight/coresight-etm4x-core.c | 18 +++++-------------
.../coresight/coresight-etm4x-sysfs.c | 7 ++-----
drivers/hwtracing/coresight/coresight-etm4x.h | 3 ++-
4 files changed, 9 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 6443f3717b37..b7abb171f523 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 &&
- (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
+ (caps->ss_status[n] & TRCSSCSRn_PC);
}

u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
@@ -571,11 +571,9 @@ 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 bit on restart if using single-shot */
+ etm4x_relaxed_write32(csa, caps->ss_status[i], TRCSSCSRn(i));
if (etm4x_sspcicrn_present(drvdata, i))
etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
}
@@ -1053,12 +1051,6 @@ 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] =
@@ -1501,8 +1493,8 @@ 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_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+ caps->ss_status[i] &= ~(TRCSSCSRn_STATUS | TRCSSCSRn_PENDING);
}
/* 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 3d5f343130bd..c794fc9de5b6 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1832,8 +1832,6 @@ 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;
}
@@ -1844,10 +1842,11 @@ 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_status[config->ss_idx];
raw_spin_unlock(&drvdata->spinlock);
return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
}
@@ -1882,8 +1881,6 @@ 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 3e20561672dc..57508d301327 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)
@@ -898,6 +899,7 @@ struct etmv4_caps {
bool atbtrig : 1;
bool lpoverride : 1;
bool skip_power_up : 1;
+ u32 ss_status[ETM_MAX_SS_CMP];
};

/**
@@ -976,7 +978,6 @@ 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}