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In-Reply-To: <97d53224-0749-086b-b2b4-12c91ec8ad5a@arm.com>
From:   Mike Leach <mike.leach@linaro.org>
Date:   Mon, 12 Apr 2021 12:29:13 +0100
Message-ID: <CAJ9a7Vh23-nFNRdQQZY4s4fGD8xhnE+PQUAE0US8fpsr-ZnsRQ@mail.gmail.com>
Subject: Re: [PATCH v6 07/10] coresight: etm4x: Add complex configuration
 handlers to etmv4
To:     Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Coresight ML <coresight@lists.linaro.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Yabin Cui <yabinc@google.com>, Leo Yan <leo.yan@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Tingwei Zhang <tingwei@codeaurora.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

HI Suzuki,

On Mon, 12 Apr 2021 at 11:28, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>
> On 09/04/2021 11:37, Mike Leach wrote:
> > Adds in handlers to allow the ETMv4 to use the complex configuration
> > support. Features and configurations can be loaded and selected in the
> > device.
> >
> > Signed-off-by: Mike Leach <mike.leach@linaro.org>
> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> >   drivers/hwtracing/coresight/Makefile          |   3 +-
> >   .../hwtracing/coresight/coresight-etm4x-cfg.c | 182 ++++++++++++++++++
> >   .../hwtracing/coresight/coresight-etm4x-cfg.h |  15 ++
> >   .../coresight/coresight-etm4x-core.c          |  38 +++-
> >   .../coresight/coresight-etm4x-sysfs.c         |   3 +
> >   5 files changed, 238 insertions(+), 3 deletions(-)
> >   create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> >   create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.h
> >
> > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> > index 63ecfc3cf66d..9420d33b23ac 100644
> > --- a/drivers/hwtracing/coresight/Makefile
> > +++ b/drivers/hwtracing/coresight/Makefile
> > @@ -16,7 +16,8 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o
> >   coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \
> >                    coresight-etm3x-sysfs.o
> >   obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o
> > -coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o
> > +coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o \
> > +                     coresight-etm4x-cfg.o
> >   obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
> >   obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
> >   obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > new file mode 100644
> > index 000000000000..d2ea903231b2
> > --- /dev/null
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > @@ -0,0 +1,182 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright(C) 2020 Linaro Limited. All rights reserved.
> > + * Author: Mike Leach <mike.leach@linaro.org>
> > + */
> > +
>
> > +#include "coresight-etm4x.h"
> > +#include "coresight-etm4x-cfg.h"
> > +#include "coresight-priv.h"
> > +#include "coresight-syscfg.h"
> > +
> > +/* defines to associate register IDs with driver data locations */
> > +#define CHECKREG(cval, elem) \
> > +     { \
> > +             if (offset == cval) { \
> > +                     reg_csdev->driver_regval = &drvcfg->elem; \
> > +                     err = 0; \
> > +                     break; \
> > +             } \
> > +     }
> > +
> > +#define CHECKREGIDX(cval, elem, off_idx, mask)       \
> > +     { \
> > +             if (mask == cval) { \
> > +                     reg_csdev->driver_regval = &drvcfg->elem[off_idx]; \
> > +                     err = 0; \
> > +                     break; \
> > +             } \
> > +     }
> > +
> > +/**
> > + * etm4_cfg_map_reg_offset - validate and map the register offset into a
> > + *                        location in the driver config struct.
> > + *
> > + * Limits the number of registers that can be accessed and programmed in
> > + * features, to those which are used to control the trace capture parameters.
> > + *
> > + * Omits or limits access to those which the driver must use exclusively.
> > + *
> > + * Invalid offsets will result in fail code return and feature load failure.
> > + *
> > + * @drvdata: driver data to map into.
> > + * @reg:     register to map.
> > + * @offset:  device offset for the register
> > + */
> > +static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
> > +                                struct cscfg_regval_csdev *reg_csdev, u32 offset)
> > +{
> > +     int err = -EINVAL, idx;
> > +     struct etmv4_config *drvcfg = &drvdata->config;
> > +     u32 off_mask;
> > +
> > +     if (((offset >= TRCEVENTCTL0R) && (offset <= TRCVIPCSSCTLR)) ||
> > +         ((offset >= TRCSEQRSTEVR) && (offset <= TRCEXTINSELR)) ||
> > +         ((offset >= TRCCIDCCTLR0) && (offset <= TRCVMIDCCTLR1))) {
> > +             do {
> > +                     CHECKREG(TRCEVENTCTL0R, eventctrl0);
> > +                     CHECKREG(TRCEVENTCTL1R, eventctrl1);
> > +                     CHECKREG(TRCSTALLCTLR, stall_ctrl);
> > +                     CHECKREG(TRCTSCTLR, ts_ctrl);
> > +                     CHECKREG(TRCSYNCPR, syncfreq);
> > +                     CHECKREG(TRCCCCTLR, ccctlr);
> > +                     CHECKREG(TRCBBCTLR, bb_ctrl);
> > +                     CHECKREG(TRCVICTLR, vinst_ctrl);
> > +                     CHECKREG(TRCVIIECTLR, viiectlr);
> > +                     CHECKREG(TRCVISSCTLR, vissctlr);
> > +                     CHECKREG(TRCVIPCSSCTLR, vipcssctlr);
> > +                     CHECKREG(TRCSEQRSTEVR, seq_rst);
> > +                     CHECKREG(TRCSEQSTR, seq_state);
> > +                     CHECKREG(TRCEXTINSELR, ext_inp);
> > +                     CHECKREG(TRCCIDCCTLR0, ctxid_mask0);
> > +                     CHECKREG(TRCCIDCCTLR1, ctxid_mask1);
> > +                     CHECKREG(TRCVMIDCCTLR0, vmid_mask0);
> > +                     CHECKREG(TRCVMIDCCTLR1, vmid_mask1);
> > +             } while (0);
> > +     } else if ((offset & GENMASK(11, 4)) == TRCSEQEVRn(0)) {
> > +             /* sequencer state control registers */
> > +             idx = (offset & GENMASK(3, 0)) / 4;
> > +             if (idx < ETM_MAX_SEQ_STATES) {
> > +                     reg_csdev->driver_regval = &drvcfg->seq_ctrl[idx];
> > +                     err = 0;
> > +             }
> > +     } else if ((offset >= TRCSSCCRn(0)) && (offset <= TRCSSPCICRn(7))) {
> > +             /* 32 bit, 8 off indexed register sets */
> > +             idx = (offset & GENMASK(4, 0)) / 4;
> > +             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))) {
> > +             /* 64 bit, 8 off indexed register sets */
> > +             idx = (offset & GENMASK(5, 0)) / 8;
> > +             off_mask = (offset & GENMASK(11, 6));
> > +             do {
> > +                     CHECKREGIDX(TRCCIDCVRn(0), ctxid_pid, idx, off_mask);
> > +                     CHECKREGIDX(TRCVMIDCVRn(0), vmid_val, idx, off_mask);
> > +             } while (0);
> > +     } else if ((offset >= TRCRSCTLRn(2)) &&
> > +                (offset <= TRCRSCTLRn((ETM_MAX_RES_SEL - 1)))) {
> > +             /* 32 bit resource selection regs, 32 off, skip fixed 0,1 */
> > +             idx = (offset & GENMASK(6, 0)) / 4;
> > +             if (idx < ETM_MAX_RES_SEL) {
> > +                     reg_csdev->driver_regval = &drvcfg->res_ctrl[idx];
> > +                     err = 0;
> > +             }
> > +     } else if ((offset >= TRCACVRn(0)) &&
> > +                (offset <= TRCACATRn((ETM_MAX_SINGLE_ADDR_CMP - 1)))) {
> > +             /* 64 bit addr cmp regs, 16 off */
> > +             idx = (offset & GENMASK(6, 0)) / 8;
> > +             off_mask = offset & GENMASK(11, 7);
> > +             do {
> > +                     CHECKREGIDX(TRCACVRn(0), addr_val, idx, off_mask);
> > +                     CHECKREGIDX(TRCACATRn(0), addr_acc, idx, off_mask);
> > +             } while (0);
> > +     } else if ((offset >= TRCCNTRLDVRn(0)) &&
> > +                (offset <= TRCCNTVRn((ETMv4_MAX_CNTR - 1)))) {
> > +             /* 32 bit counter regs, 4 off (ETMv4_MAX_CNTR - 1) */
> > +             idx = (offset &  GENMASK(3, 0)) / 4;
> > +             off_mask = offset &  GENMASK(11, 4);
> > +             do {
> > +                     CHECKREGIDX(TRCCNTRLDVRn(0), cntrldvr, idx, off_mask);
> > +                     CHECKREGIDX(TRCCNTCTLRn(0), cntr_ctrl, idx, off_mask);
> > +                     CHECKREGIDX(TRCCNTVRn(0), cntr_val, idx, off_mask);
> > +             } while (0);
> > +     }
> > +     return err;
> > +}
> > +
> > +/**
> > + * etm4_cfg_load_feature - load a feature into a device instance.
> > + *
> > + * @csdev:   An ETMv4 CoreSight device.
> > + * @feat:    The feature to be loaded.
> > + *
> > + * The function will load a feature instance into the device, checking that
> > + * the register definitions are valid for the device.
> > + *
> > + * Parameter and register definitions will be converted into internal
> > + * structures that are used to set the values in the driver when the
> > + * feature is enabled for the device.
> > + *
> > + * The feature spinlock pointer is initialised to the same spinlock
> > + * that the driver uses to protect the internal register values.
> > + */
> > +static int etm4_cfg_load_feature(struct coresight_device *csdev,
> > +                              struct cscfg_feature_csdev *feat_csdev)
> > +{
> > +     struct device *dev = csdev->dev.parent;
> > +     struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
> > +     const struct cscfg_feature_desc *feat_desc = feat_csdev->feat_desc;
> > +     u32 offset;
> > +     int i = 0, err = 0;
> > +
> > +     /*
> > +      * essential we set the device spinlock - this is used in the generic
> > +      * programming routines when copying values into the drvdata structures
> > +      * via the pointers setup in etm4_cfg_map_reg_offset().
> > +      */
> > +     feat_csdev->drv_spinlock = &drvdata->spinlock;
> > +
> > +     /* process the register descriptions */
> > +     for (i = 0; i < feat_csdev->nr_regs && !err; i++) {
> > +             offset = feat_desc->regs_desc[i].offset;
> > +             err = etm4_cfg_map_reg_offset(drvdata, &feat_csdev->regs_csdev[i], offset);
> > +     }
> > +     return err;
> > +}
> > +
> > +/* match information when loading configurations */
> > +#define CS_CFG_ETM4_MATCH_FLAGS      (CS_CFG_MATCH_CLASS_SRC_ALL | \
> > +                              CS_CFG_MATCH_CLASS_SRC_ETM4)
> > +
> > +int etm4_cscfg_register(struct coresight_device *csdev)
> > +{
> > +     struct cscfg_csdev_feat_ops ops;
> > +
> > +     ops.load_feat = &etm4_cfg_load_feature;
> > +
> > +     return cscfg_register_csdev(csdev, CS_CFG_ETM4_MATCH_FLAGS, &ops);
> > +}
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.h b/drivers/hwtracing/coresight/coresight-etm4x-cfg.h
> > new file mode 100644
> > index 000000000000..a204ad9a4792
> > --- /dev/null
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.h
> > @@ -0,0 +1,15 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (c) 2014-2020, The Linux Foundation. All rights reserved.
> > + */
> > +
> > +#ifndef _CORESIGHT_ETM4X_CFG_H
> > +#define _CORESIGHT_ETM4X_CFG_H
>
>
> Looks like this must be guarded by the CONFIG_CORESIGHT_SOURCE_ETM4X to
> prevent the build failures on arm, as reported by the test robot.
>

The test robot was complaining about
#include <asm/sysregs.h>
in the next patch and not this one. I haven't seen any issues reported
with this patch.

Moreover - if this is required - then removing the ETM4 module from
the config - i.e. not defining CONFIG_CORESIGHT_SOURCE_ETM4X - should
trigger the error. I have done a clean build, without ETM4 and the
error does not occur. (I also tried out gcc 9 in case this was a
factor - it was not)

I have to confess I am completely puzzled by this - how can this
include only trigger an issue with my patch when it has been in the
source for some time, and the same header (coresight-etm4x.h) is
included without apparent problems elsewhere in the coresight build.

Without a reliable reproducer, or a credible explanation, I can only
assume that this is an issue with the test robot itself.

I am open to further suggestions!

Thanks

Mike


> #ifdef CONFIG_CORESIGHT_SOURCE_ETM4X
>
> > +
> > +#include "coresight-config.h"
> > +#include "coresight-etm4x.h"
> > +
> > +/* ETMv4 specific config functions */
> > +int etm4_cscfg_register(struct coresight_device *csdev);
> > +
>
> endif /* ETM4X */
>
> Cheers
> Suzuki
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK