From: Suzuki K Poulose suzuki.poulose@arm.com
ETE may not implement the OS lock and instead could rely on the PE OS Lock for the trace unit access. This is indicated by the TRCOLSR.OSM == 0b100. Add support for handling the PE OS lock
Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 50 ++++++++++++++++++---- drivers/hwtracing/coresight/coresight-etm4x.h | 15 +++++++ 2 files changed, 56 insertions(+), 9 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index fd945c1..0269b4c 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -101,30 +101,59 @@ void etm4x_sysreg_write(struct csdev_access *csa, } }
-static void etm4_os_unlock_csa(struct etmv4_drvdata *drvdata, struct csdev_access *csa) +static void etm_detect_os_lock(struct etmv4_drvdata *drvdata, + struct csdev_access *csa) { - /* Writing 0 to TRCOSLAR unlocks the trace registers */ - etm4x_relaxed_write32(csa, 0x0, TRCOSLAR); - drvdata->os_unlock = true; + 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, @@ -794,6 +823,9 @@ static void etm4_init_arch_data(void *info) if (!etm_init_csdev_access(drvdata, csa)) return;
+ /* Detect the support for OS Lock before we actuall 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); diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index fe71072..4b1bfc2 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -497,6 +497,20 @@ 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 @@ -879,6 +893,7 @@ 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;