Message ID | 20201214173731.302520-1-suzuki.poulose@arm.com (mailing list archive) |
---|---|
Headers | show |
Series | coresight: etm4x: Support for system instructions | expand |
Hi Suzuki, In addition to altering patch 18, to put the newly accessible TRCDEVARCH register into the more appropriate 'mgmt' subdir for CoreSight management registers, an update is needed to ./Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x to add a reference for this new sysfs file to reflect the location and purpose of the register. Thanks Mike On Mon, 14 Dec 2020 at 17:37, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > CoreSight ETMv4.4 obsoletes memory mapped access to ETM and > mandates the system instructions for registers. > This also implies that they may not be on the amba bus. > Right now all the CoreSight components are accessed via memory > map. Also, we have some common routines in coresight generic > code driver (e.g, CS_LOCK, claim/disclaim), which assume the > mmio. In order to preserve the generic algorithms at a single > place and to allow dynamic switch for ETMs, this series introduces > an abstraction layer for accessing a coresight device. It is > designed such that the mmio access are fast tracked (i.e, without > an indirect function call). > > This will also help us to get rid of the driver+attribute specific > sysfs show/store routines and replace them with a single routine > to access a given register offset (which can be embedded in the > dev_ext_attribute). This is not currently implemented in the series, > but can be achieved. > > Further we switch the generic routines to work with the abstraction. > With this in place, we refactor the etm4x code a bit to allow for > supporting the system instructions with very little new code. The > changes also switch to using the system instructions by default > even when we may have an MMIO. > > We use TRCDEVARCH for the detection of the ETM component, which > is a standard register as per CoreSight architecture, rather than > the etm specific id register TRCIDR1. This is for making sure > that we are able to detect the ETM via system instructions accurately, > when the the trace unit could be anything (etm or a custom trace unit). > To keep the backward compatibility for any existing broken > impelementation which may not implement TRCDEVARCH, we fall back to TRCIDR1. > Also this covers us for the changes in the future architecture [0]. > > Also, v8.4 self-hosted tracing extensions (coupled with ETMv4.4) adds > new filtering registers for trace by exception level. So on a v8.4 > system, with Trace Filtering support, without the appropriate > programming of the Trace filter registers (TRFCR_ELx), tracing > will not be enabled. This series also includes the TraceFiltering > support to cover the ETM-v4.4 support. > > The series has been mildly tested on a model for system instructions. > I would really appreciate any testing on real hardware. > > Applies on coresight/next. A tree is available here [1]. > > > [0] https://developer.arm.com/docs/ddi0601/g/aarch64-system-registers/trcidr1 > [1] https://gitlab.arm.com/linux-arm/linux-skp coresight/etm/sysreg-v5 > > Changes since v4: > - Fix typo in commit description for the patches 02 & 15 > - Refactor the AMBA device "remove" call back for use with > paltform_driver. (patch 21). Thus remove Review tag by Mathieu, > even though the changes are minimal. > - Added "remove" callback for platform_driver in patch 22, removed > Review tag by Mathieu > - Add 'U' suffix for constants in Patch 24 (Catalin) > - Fixed field extraction in Patch 25 > > Changes since v3: > - Device tree compatible changed to etm4x > - Use etm4x_** instead of generalizing etm_ in etm4x driver. > - Added v8.4 self hosted trace support patches, reworked > from Jonathan's series. > - Dropped queued patches. > - Expose TRCDEVARCH via trcidr, as this will be needed for > the userspace tools to determine the trace major/minor > arch versions. > - Remove csa argument to read()/write() (Mathieu) > - Fix secure exception mask calculation (Mathieu) > - Fix various coding style comments (Mathieu) > (See individual patches for change log) > > Changes since V2: > - Several fixes to the ETM register accesses. Access a register > when it is present. > - Add support for TRCIDR3.NUMPROCS for v4.2+ > - Drop OS lock detection. Use software lock only in case of mmio. > - Fix issues with the Exception level masks (Mike Leach) > - Fall back to using TRCIDR1 when TRCDEVARCH is not "present" > - Use a generic notion of ETM architecture (rather than using > the encoding as in registers) > - Fixed some checkpatch issues. > - Changed the dts compatible string to "arm,coresight-etm-sysreg" > (Mike Leach) > > Changes since V1: > - Flip the switch for iomem from no_iomem to io_mem in csdev_access. > - Split patches for claim/disclaim and CS_LOCK/UNLOCK conversions. > - Move device access initialisation for etm4x to the target CPU > - Cleanup secure exception level mask handling. > - Switch to use TRCDEVARCH for ETM component discovery. This > is for making > - Check the availability of OS/Software Locks before using them. > > Known issues: > Checkpatch failure for "coresight: etm4x: Add sysreg access helpers" : > > ERROR: Macros with complex values should be enclosed in parentheses > #121: FILE: drivers/hwtracing/coresight/coresight-etm4x.h:153: > +#define CASE_READ(res, x) \ > + case (x): { (res) = read_etm4x_sysreg_const_offset((x)); break; } > > I don't know a way to fix the warning without loosing the code > readability, which I believe is crucial for such a construct. > > > Jonathan Zhou (2): > arm64: Add TRFCR_ELx definitions > coresight: Add support for v8.4 SelfHosted tracing > > Suzuki K Poulose (23): > coresight: etm4x: Handle access to TRCSSPCICRn > coresight: etm4x: Skip accessing TRCPDCR in save/restore > coresight: Introduce device access abstraction > coresight: tpiu: Prepare for using coresight device access abstraction > coresight: Convert coresight_timeout to use access abstraction > coresight: Convert claim/disclaim operations to use access wrappers > coresight: etm4x: Always read the registers on the host CPU > coresight: etm4x: Convert all register accesses > coresight: etm4x: Add commentary on the registers > coresight: etm4x: Add sysreg access helpers > coresight: etm4x: Define DEVARCH register fields > coresight: etm4x: Check for Software Lock > coresight: etm4x: Cleanup secure exception level masks > coresight: etm4x: Clean up exception level masks > coresight: etm4x: Handle ETM architecture version > coresight: etm4x: Detect access early on the target CPU > coresight: etm4x: Use TRCDEVARCH for component discovery > coresight: etm4x: Expose trcdevarch via trcidr > coresight: etm4x: Add necessary synchronization for sysreg access > coresight: etm4x: Detect system instructions support > coresight: etm4x: Refactor probing routine > coresight: etm4x: Add support for sysreg only devices > dts: bindings: coresight: ETM system register access only units > > .../devicetree/bindings/arm/coresight.txt | 5 +- > arch/arm64/include/asm/sysreg.h | 11 + > drivers/hwtracing/coresight/coresight-catu.c | 12 +- > drivers/hwtracing/coresight/coresight-core.c | 122 ++- > .../hwtracing/coresight/coresight-cti-core.c | 18 +- > drivers/hwtracing/coresight/coresight-etb10.c | 10 +- > .../coresight/coresight-etm3x-core.c | 9 +- > .../coresight/coresight-etm4x-core.c | 796 ++++++++++++------ > .../coresight/coresight-etm4x-sysfs.c | 46 +- > drivers/hwtracing/coresight/coresight-etm4x.h | 498 ++++++++++- > .../hwtracing/coresight/coresight-funnel.c | 7 +- > .../coresight/coresight-replicator.c | 13 +- > drivers/hwtracing/coresight/coresight-stm.c | 4 +- > .../hwtracing/coresight/coresight-tmc-core.c | 16 +- > .../hwtracing/coresight/coresight-tmc-etf.c | 10 +- > .../hwtracing/coresight/coresight-tmc-etr.c | 4 +- > drivers/hwtracing/coresight/coresight-tpiu.c | 31 +- > include/linux/coresight.h | 225 ++++- > 18 files changed, 1406 insertions(+), 431 deletions(-) > > -- > 2.24.1 > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
Hi Mike, On 1/6/21 2:48 PM, Mike Leach wrote: > Hi Suzuki, > > In addition to altering patch 18, to put the newly accessible > TRCDEVARCH register into the more appropriate 'mgmt' subdir for > CoreSight management registers, an update is needed to > ./Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x to add a > reference for this new sysfs file to reflect the location and purpose > of the register. Ack. I will do this for the next version. Cheers Suzuki