TPIU driver access the device before the coresight device
is registered. In other words, before the drvdata->csdev
is valid. Thus, we need to make sure that the csdev_access
is valid for both the invocations. Switch to using the
csdev_access directly instead of relying on availability
of drvdata->csdev.
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Signed-off-by: Suzuki K Poulose <[email protected]>
---
drivers/hwtracing/coresight/coresight-tpiu.c | 30 +++++++++-----------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 7ef7649f48ad..84ff4bf5d3b8 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -60,49 +60,45 @@ struct tpiu_drvdata {
struct coresight_device *csdev;
};
-static void tpiu_enable_hw(struct tpiu_drvdata *drvdata)
+static void tpiu_enable_hw(struct csdev_access *csa)
{
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(csa->base);
/* TODO: fill this up */
- CS_LOCK(drvdata->base);
+ CS_LOCK(csa->base);
}
static int tpiu_enable(struct coresight_device *csdev, u32 mode, void *__unused)
{
- struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
-
- tpiu_enable_hw(drvdata);
+ tpiu_enable_hw(&csdev->access);
atomic_inc(csdev->refcnt);
dev_dbg(&csdev->dev, "TPIU enabled\n");
return 0;
}
-static void tpiu_disable_hw(struct tpiu_drvdata *drvdata)
+static void tpiu_disable_hw(struct csdev_access *csa)
{
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(csa->base);
/* Clear formatter and stop on flush */
- writel_relaxed(FFCR_STOP_FI, drvdata->base + TPIU_FFCR);
+ csdev_access_relaxed_write32(csa, FFCR_STOP_FI, TPIU_FFCR);
/* Generate manual flush */
- writel_relaxed(FFCR_STOP_FI | FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
+ csdev_access_relaxed_write32(csa, FFCR_STOP_FI | FFCR_FON_MAN, TPIU_FFCR);
/* Wait for flush to complete */
- coresight_timeout(drvdata->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
+ coresight_timeout(csa->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
/* Wait for formatter to stop */
- coresight_timeout(drvdata->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
+ coresight_timeout(csa->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
- CS_LOCK(drvdata->base);
+ CS_LOCK(csa->base);
}
static int tpiu_disable(struct coresight_device *csdev)
{
- struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
-
if (atomic_dec_return(csdev->refcnt))
return -EBUSY;
- tpiu_disable_hw(drvdata);
+ tpiu_disable_hw(&csdev->access);
dev_dbg(&csdev->dev, "TPIU disabled\n");
return 0;
@@ -152,7 +148,7 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
desc.access.base = base;
/* Disable tpiu to support older devices */
- tpiu_disable_hw(drvdata);
+ tpiu_disable_hw(&desc.access);
pdata = coresight_get_platform_data(dev);
if (IS_ERR(pdata))
--
2.24.1
On Wed, Jul 22, 2020 at 06:20:29PM +0100, Suzuki K Poulose wrote:
> TPIU driver access the device before the coresight device
> is registered. In other words, before the drvdata->csdev
> is valid. Thus, we need to make sure that the csdev_access
> is valid for both the invocations. Switch to using the
> csdev_access directly instead of relying on availability
> of drvdata->csdev.
I'm not sure all of the above is needed and based on the wording I could easily
see this patch being selected for stable backport, which would be a mistak.
The gist of this patch is that we are moving to the access abstraction and the
changelog should reflect that.
>
> Cc: Mathieu Poirier <[email protected]>
> Cc: Mike Leach <[email protected]>
> Signed-off-by: Suzuki K Poulose <[email protected]>
> ---
> drivers/hwtracing/coresight/coresight-tpiu.c | 30 +++++++++-----------
> 1 file changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
> index 7ef7649f48ad..84ff4bf5d3b8 100644
> --- a/drivers/hwtracing/coresight/coresight-tpiu.c
> +++ b/drivers/hwtracing/coresight/coresight-tpiu.c
> @@ -60,49 +60,45 @@ struct tpiu_drvdata {
> struct coresight_device *csdev;
> };
>
> -static void tpiu_enable_hw(struct tpiu_drvdata *drvdata)
> +static void tpiu_enable_hw(struct csdev_access *csa)
> {
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(csa->base);
>
> /* TODO: fill this up */
>
> - CS_LOCK(drvdata->base);
> + CS_LOCK(csa->base);
> }
>
> static int tpiu_enable(struct coresight_device *csdev, u32 mode, void *__unused)
> {
> - struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> -
> - tpiu_enable_hw(drvdata);
> + tpiu_enable_hw(&csdev->access);
> atomic_inc(csdev->refcnt);
> dev_dbg(&csdev->dev, "TPIU enabled\n");
> return 0;
> }
>
> -static void tpiu_disable_hw(struct tpiu_drvdata *drvdata)
> +static void tpiu_disable_hw(struct csdev_access *csa)
> {
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(csa->base);
>
> /* Clear formatter and stop on flush */
> - writel_relaxed(FFCR_STOP_FI, drvdata->base + TPIU_FFCR);
> + csdev_access_relaxed_write32(csa, FFCR_STOP_FI, TPIU_FFCR);
> /* Generate manual flush */
> - writel_relaxed(FFCR_STOP_FI | FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
> + csdev_access_relaxed_write32(csa, FFCR_STOP_FI | FFCR_FON_MAN, TPIU_FFCR);
> /* Wait for flush to complete */
> - coresight_timeout(drvdata->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
> + coresight_timeout(csa->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
> /* Wait for formatter to stop */
> - coresight_timeout(drvdata->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
> + coresight_timeout(csa->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
>
> - CS_LOCK(drvdata->base);
> + CS_LOCK(csa->base);
> }
>
> static int tpiu_disable(struct coresight_device *csdev)
> {
> - struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> -
> if (atomic_dec_return(csdev->refcnt))
> return -EBUSY;
>
> - tpiu_disable_hw(drvdata);
> + tpiu_disable_hw(&csdev->access);
>
> dev_dbg(&csdev->dev, "TPIU disabled\n");
> return 0;
> @@ -152,7 +148,7 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
> desc.access.base = base;
Any reason for introducing the above in patch 02? I would have done that as
part of this patch... Also part of this patch I would remove drvdata::base
since it is no longer needed.
I'm out of time for today - I will continue tomorrow.
Regards,
Mathieu
>
> /* Disable tpiu to support older devices */
> - tpiu_disable_hw(drvdata);
> + tpiu_disable_hw(&desc.access);
>
> pdata = coresight_get_platform_data(dev);
> if (IS_ERR(pdata))
> --
> 2.24.1
>
On 07/29/2020 10:01 PM, Mathieu Poirier wrote:
> On Wed, Jul 22, 2020 at 06:20:29PM +0100, Suzuki K Poulose wrote:
>> TPIU driver access the device before the coresight device
>> is registered. In other words, before the drvdata->csdev
>> is valid. Thus, we need to make sure that the csdev_access
>> is valid for both the invocations. Switch to using the
>> csdev_access directly instead of relying on availability
>> of drvdata->csdev.
>
> I'm not sure all of the above is needed and based on the wording I could easily
> see this patch being selected for stable backport, which would be a mistak.
>
> The gist of this patch is that we are moving to the access abstraction and the
> changelog should reflect that.
True, I will make it something like :
"Prepare the TPIU driver to make use of the CoreSight device access
abstraction layer. The driver touches the device even before the
coresight device is registered. Thus we could be accessing the
devices without a csdev. As we are about to use the abstraction
layer for accessing the device, pass in the access directly
to avoid having to deal with the un-initialised csdev.
>>
>> static int tpiu_disable(struct coresight_device *csdev)
>> {
>> - struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>> -
>> if (atomic_dec_return(csdev->refcnt))
>> return -EBUSY;
>>
>> - tpiu_disable_hw(drvdata);
>> + tpiu_disable_hw(&csdev->access);
>>
>> dev_dbg(&csdev->dev, "TPIU disabled\n");
>> return 0;
>> @@ -152,7 +148,7 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
>> desc.access.base = base;
>
> Any reason for introducing the above in patch 02? I would have done that as
> part of this patch... Also part of this patch I would remove drvdata::base
> since it is no longer needed.
The patch 02 is not touching how the individual drivers access the
device, yet. It only sets the way by introducing the layer. As per
the proposed change, this is a preparation of the TPIU driver, so
that we can convert the generic helper functions ( coresight_timeout())
more easily and keep the patch 05 easier for review (just like the Patch
4, which prepares the ETM driver).
Cheers
Suzuki
>
> I'm out of time for today - I will continue tomorrow.
>
> Regards,
> Mathieu
>
>>
>> /* Disable tpiu to support older devices */
>> - tpiu_disable_hw(drvdata);
>> + tpiu_disable_hw(&desc.access);
>>
>> pdata = coresight_get_platform_data(dev);
>> if (IS_ERR(pdata))
>> --
>> 2.24.1
>>