Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 14 Feb 2024 10:16:56 +0000 | Subject | Re: [PATCH V4 03/11] coresight: tmc: Extract device properties from AMBA pid based table lookup | From | Suzuki K Poulose <> |
| |
On 14/02/2024 03:35, Anshuman Khandual wrote: > > > On 2/13/24 16:02, Suzuki K Poulose wrote: >> On 13/02/2024 03:13, Anshuman Khandual wrote: >>> >>> >>> On 2/12/24 17:43, Suzuki K Poulose wrote: >>>> On 23/01/2024 05:46, Anshuman Khandual wrote: >>>>> This extracts device properties from AMBA pid based table lookup. This also >>>>> defers tmc_etr_setup_caps() after the coresight device has been initialized >>>>> so that PID value can be read. >>>>> >>>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> >>>>> Cc: Mike Leach <mike.leach@linaro.org> >>>>> Cc: James Clark <james.clark@arm.com> >>>>> Cc: coresight@lists.linaro.org >>>>> Cc: linux-arm-kernel@lists.infradead.org >>>>> Cc: linux-kernel@vger.kernel.org >>>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >>>>> --- >>>>> .../hwtracing/coresight/coresight-tmc-core.c | 19 +++++++++++++------ >>>>> 1 file changed, 13 insertions(+), 6 deletions(-) >>>>> >>>>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c >>>>> index 7ec5365e2b64..e71db3099a29 100644 >>>>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c >>>>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c >>>>> @@ -370,16 +370,24 @@ static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata) >>>>> return (auth & TMC_AUTH_NSID_MASK) == 0x3; >>>>> } >>>>> +#define TMC_AMBA_MASK 0xfffff >>>>> + >>>>> +static const struct amba_id tmc_ids[]; >>>>> + >>>>> /* Detect and initialise the capabilities of a TMC ETR */ >>>>> -static int tmc_etr_setup_caps(struct device *parent, u32 devid, void *dev_caps) >>>>> +static int tmc_etr_setup_caps(struct device *parent, u32 devid) >>>>> { >>>>> int rc; >>>>> - u32 dma_mask = 0; >>>>> + u32 tmc_pid, dma_mask = 0; >>>>> struct tmc_drvdata *drvdata = dev_get_drvdata(parent); >>>>> + void *dev_caps; >>>>> if (!tmc_etr_has_non_secure_access(drvdata)) >>>>> return -EACCES; >>>>> + tmc_pid = coresight_get_pid(&drvdata->csdev->access) & TMC_AMBA_MASK; >>>>> + dev_caps = coresight_get_uci_data_from_amba(tmc_ids, tmc_pid); >>>>> + >>>>> /* Set the unadvertised capabilities */ >>>>> tmc_etr_init_caps(drvdata, (u32)(unsigned long)dev_caps); >>>>> @@ -497,10 +505,6 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) >>>>> desc.type = CORESIGHT_DEV_TYPE_SINK; >>>>> desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM; >>>>> desc.ops = &tmc_etr_cs_ops; >>>>> - ret = tmc_etr_setup_caps(dev, devid, >>>>> - coresight_get_uci_data(id)); >>>>> - if (ret) >>>>> - goto out; >>>>> idr_init(&drvdata->idr); >>>>> mutex_init(&drvdata->idr_mutex); >>>>> dev_list = &etr_devs; >>>>> @@ -539,6 +543,9 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) >>>>> goto out; >>>>> } >>>>> + if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) >>>>> + ret = tmc_etr_setup_caps(dev, devid); >>>>> + >>>> >>>> With this change, we silently accept an ETR that may only have "SECURE" access only and crash later while we try to enable tracing. You could >>>> pass in the "access" (which is already in 'desc.access' in the original >>>> call site and deal with it ? >>> >>> Just wondering, if something like the following will help ? A failed tmc_etr_setup_caps() >>> because of failed tmc_etr_has_non_secure_access(), will unregister the coresight device >>> before returning. >>> >>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c >>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c >>> @@ -538,8 +538,13 @@ static int __tmc_probe(struct device *dev, struct resource *res) >>> goto out; >>> } >>> - if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) >>> + if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { >>> ret = tmc_etr_setup_caps(dev, devid); >>> + if (ret) { >>> + coresight_unregister(drvdata->csdev); >>> + goto out; >>> + } >>> + } >> >> Why do we move the tmc_etr_setup_caps() in the first place ? We could retain where that was and pass "desc.access" parameter rather than registering the csdev and then relying csdev->access ? > > Agreed, and after implementing the changes suggested above, the entire patch > will look something like the following. Please do confirm if this looks good > enough. > > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -370,16 +370,25 @@ static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata) > return (auth & TMC_AUTH_NSID_MASK) == 0x3; > } > > +#define TMC_AMBA_MASK 0xfffff > + > +static const struct amba_id tmc_ids[]; > + > /* Detect and initialise the capabilities of a TMC ETR */ > -static int tmc_etr_setup_caps(struct device *parent, u32 devid, void *dev_caps) > +static int tmc_etr_setup_caps(struct device *parent, u32 devid, > + struct csdev_access *access) > { > int rc; > - u32 dma_mask = 0; > + u32 tmc_pid, dma_mask = 0; > struct tmc_drvdata *drvdata = dev_get_drvdata(parent); > + void *dev_caps; > > if (!tmc_etr_has_non_secure_access(drvdata)) > return -EACCES; > > + tmc_pid = coresight_get_pid(access) & TMC_AMBA_MASK; > + dev_caps = coresight_get_uci_data_from_amba(tmc_ids, tmc_pid); > + > /* Set the unadvertised capabilities */ > tmc_etr_init_caps(drvdata, (u32)(unsigned long)dev_caps); > > @@ -497,8 +506,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) > desc.type = CORESIGHT_DEV_TYPE_SINK; > desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM; > desc.ops = &tmc_etr_cs_ops; > - ret = tmc_etr_setup_caps(dev, devid, > - coresight_get_uci_data(id)); > + ret = tmc_etr_setup_caps(dev, devid, &desc.access); > if (ret) > goto out; > idr_init(&drvdata->idr); >
That looks much better. Thanks
Suzuki
| ![\](/images/icornerr.gif) |