When the kernel is running at EL2, the PID is stored in CONTEXTIDR_EL2.
So, tracing CONTEXTIDR_EL1 doesn't give us the pid of the process.
Thus we should trace the VMID with VMIDOPT set to trace CONTEXTIDR_EL2
instead of CONTEXTIDR_EL1.  Given that we have an existing config
option "contextid" and this will be useful for tracing virtual machines
(when we get to support virtualization).

So instead, this patch extends option CTXTID with an extra bit
ETM_OPT_CTXTID2 (bit 15), thus on an EL2 kernel, we will have another
bit available for the perf tool: ETM_OPT_CTXTID is for kernel running in
EL1, ETM_OPT_CTXTID2 is used when kernel runs in EL2 with VHE enabled.

The tool must be backward compatible for users, i.e, "contextid" today
traces PID and that should remain the same; for this purpose, the perf
tool is updated to automatically set corresponding bit for the
"contextid" config, therefore, the user doesn't have to bother which EL
the kernel is running.

  i.e, perf record -e cs_etm/contextid/u --

will always do the "pid" tracing, independent of the kernel EL.

The driver parses the format "contextid", which traces CONTEXTIDR_EL1
for ETM_OPT_CTXTID (on EL1 kernel) and traces CONTEXTIDR_EL2 for
ETM_OPT_CTXTID2 (on EL2 kernel).

Besides the enhancement for format "contexid", extra two formats are
introduced: "contextid1" and "contextid2".  This considers to support
tracing both CONTEXTIDR_EL1 and CONTEXTIDR_EL2 when the kernel is
running at EL2.  Finally, the PMU formats are defined as follow:

  "contextid1": Available on both EL1 kernel and EL2 kernel.  When the
                kernel is running at EL1, "contextid1" enables the PID
		tracing; when the kernel is running at EL2, this enables
		tracing the PID of guest applications.

  "contextid2": Only usable when the kernel is running at EL2.  When
                selected, enables PID tracing on EL2 kernel.

  "contextid":  Will be an alias for the option that enables PID
                tracing.  I.e,
                contextid == contextid1, on EL1 kernel.
                contextid == contextid2, on EL2 kernel.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Al Grant <al.grant@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[ Added two config formats: contextid1, contextid2 ]
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210206150833.42120-4-leo.yan@linaro.org
Link: https://lore.kernel.org/r/20210211172038.2483517-3-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In theory, the options should be arbitrary values and are neutral for
any ETM version; so far perf tool uses ETMv3.5/PTM ETMCR config bits
except for register's bit definitions, also uses as options.

This can introduce confusion, especially if we want to add a new option
but the new option is not supported by ETMv3.5/PTM ETMCR.  But on the
other hand, we cannot change options since these options are generic
CoreSight PMU ABI.

For easier maintenance and avoid confusion, this patch refines the
comment to clarify perf options, and gives out the background info for
these bits are coming from ETMv3.5/PTM.  Afterwards, we should take
these options as general knobs, and if there have any confliction with
ETMv3.5/PTM, should consider to define saperate macros for ETMv3.5/PTM
ETMCR config bits.

Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210206150833.42120-2-leo.yan@linaro.org
Link: https://lore.kernel.org/r/20210211172038.2483517-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This was non-trivial to get right because commits
c23bc382ef0e ("coresight: etm4x: Refactor probing routine") and
5214b563588e ("coresight: etm4x: Add support for sysreg only devices")
changed the code flow considerably. With this change the driver can be
built again.

Fixes: 0573d3fa4864 ("Merge branch 'devel-stable' of git://git.armlinux.org.uk/~rmk/linux-arm into char-misc-next")
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210205130848.20009-1-uwe@kleine-koenig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This merges from linux-arm at 860660fd829e ("ARM: 9055/1: mailbox:
arm_mhuv2: make remove callback return void") into char-misc-next to get
the amba fixes from Uwe.

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

TRCSTALLCTLR register is only implemented if

   TRCIDR3.STALLCTL == 0b1

Make sure the driver touches the register only it is implemented.

Link: https://lore.kernel.org/r/20210127184617.3684379-1-suzuki.poulose@arm.com
Cc: stable@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-32-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

v8.4 tracing extensions added support for trace filtering controlled
by TRFCR_ELx. This must be programmed to allow tracing at EL1/EL2 and
EL0. The timestamp used is the virtual time. Also enable CONTEXIDR_EL2
tracing if we are running the kernel at EL2.

Link: https://lore.kernel.org/r/20210110224850.1880240-29-suzuki.poulose@arm.com
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
[ Move the trace filtering setup etm_init_arch_data() and clean ups]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-31-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for devices with system instruction access only.
They don't have a memory mapped interface and thus are not
AMBA devices. System register access is not permitted to
TRCPDCR and thus skip access to them.

Link: https://lore.kernel.org/r/20210110224850.1880240-26-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-28-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As we are about to add support for system register based devices,
we don't get an AMBA pid. So, the detection code could check
the system registers running on the CPU to check for the architecture
specific features. Thus we move the arch feature detection to
run on the CPU. We cannot always read the PID from the HW, as the
PID could be overridden by DT for broken devices. So, use the
PID from AMBA layer if available.

Link: https://lore.kernel.org/r/20210110224850.1880240-25-suzuki.poulose@arm.com
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: liuqi115@huawei.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-27-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

CoreSight ETM with system register access may not have a
memory mapped i/o access. Refactor the ETM specific probing
into a common routine to allow reusing the code for such ETMs.

Link: https://lore.kernel.org/r/20210110224850.1880240-24-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-26-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ETM v4.4 onwards adds support for system instruction access
to the ETM. Detect the support on an ETM and switch to using the
mode when available.

Link: https://lore.kernel.org/r/20210110224850.1880240-23-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-25-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>