I will update this in the next patch series.On 25/10/2023 03:53, Tao Zhang wrote:Read the CMB element size from the device tree. Set the register bit that controls the CMB element size of the corresponding port. Signed-off-by: Tao Zhang <quic_taozha@quicinc.com> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> --- drivers/hwtracing/coresight/coresight-tpda.c | 108 ++++++++++++++++----------- drivers/hwtracing/coresight/coresight-tpda.h | 6 ++ 2 files changed, 69 insertions(+), 45 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c index 5f82737..3101d2a 100644 --- a/drivers/hwtracing/coresight/coresight-tpda.c +++ b/drivers/hwtracing/coresight/coresight-tpda.c @@ -28,24 +28,54 @@ static bool coresight_device_is_tpdm(struct coresight_device *csdev) CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM); } +static void tpdm_clear_element_size(struct coresight_device *csdev) +{ + struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + if (drvdata->dsb_esize) + drvdata->dsb_esize = 0; + if (drvdata->cmb_esize) + drvdata->cmb_esize = 0; +} + +static void tpda_set_element_size(struct tpda_drvdata *drvdata, u32 *val) +{ + + if (drvdata->dsb_esize == 64) + *val |= TPDA_Pn_CR_DSBSIZE; + else if (drvdata->dsb_esize == 32) + *val &= ~TPDA_Pn_CR_DSBSIZE; + + if (drvdata->cmb_esize == 64) + *val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x2); + else if (drvdata->cmb_esize == 32) + *val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x1); + else if (drvdata->cmb_esize == 8) + *val &= ~TPDA_Pn_CR_CMBSIZE; +} + /* * Read the DSB element size from the TPDM device * Returns * The dsb element size read from the devicetree if available.Hi Tao, I think the function description and the return value description above need updating now.
I will update this in the next patch series.* 0 - Otherwise, with a warning once. */ -static int tpdm_read_dsb_element_size(struct coresight_device *csdev) +static int tpdm_read_element_size(struct tpda_drvdata *drvdata, + struct coresight_device *csdev) { - int rc = 0; - u8 size = 0; - - rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent), - "qcom,dsb-element-size", &size); + int rc = -EEXIST; + + if (!fwnode_property_read_u8(dev_fwnode(csdev->dev.parent), + "qcom,dsb-element-size", &drvdata->dsb_esize)) + rc &= 0;Is &= 0 significant? Why not = 0?
+ if (!fwnode_property_read_u8(dev_fwnode(csdev->dev.parent), + "qcom,cmb-element-size", &drvdata->cmb_esize)) + rc &= 0; if (rc) dev_warn_once(&csdev->dev, - "Failed to read TPDM DSB Element size: %d\n", rc); + "Failed to read TPDM Element size: %d\n", rc); - return size; + return rc; } /* @@ -56,13 +86,17 @@ static int tpdm_read_dsb_element_size(struct coresight_device *csdev) * Parameter "inport" is used to pass in the input port number * of TPDA, and it is set to -1 in the recursize call. */ -static int tpda_get_element_size(struct coresight_device *csdev, +static int tpda_get_element_size(struct tpda_drvdata *drvdata, + struct coresight_device *csdev, int inport) { - int dsb_size = -ENOENT; - int i, size; + int rc = -ENOENT; + int i; struct coresight_device *in; + if (inport > 0) + tpdm_clear_element_size(csdev); + for (i = 0; i < csdev->pdata->nr_inconns; i++) { in = csdev->pdata->in_conns[i]->src_dev; if (!in) @@ -74,25 +108,20 @@ static int tpda_get_element_size(struct coresight_device *csdev, continue; if (coresight_device_is_tpdm(in)) { - size = tpdm_read_dsb_element_size(in); + if (rc) + rc = tpdm_read_element_size(drvdata, in); + else + return -EINVAL;This is quite hard to follow, is checking rc here before calling tpdm_read_element_size() some kind of way of only calling it once?
Yes, there can only be one TPDM on one input port of TPDA. If "tpdm_read_element_size" is called
twice, it means that two TPDMs are found on one input port of TPDA.
rc isn't actually a return value at this point, it's just default initialised to -ENOENT.
In this loop, "tpdm_read_element_size" will be called for the first time TPDM found. If rc equals to
0, it means that at lease one TPDM has been found on the input port. Does it make sense?
The same as the above.Then it's not clear why the else condition returns an error?
} else { /* Recurse down the path */ - size = tpda_get_element_size(in, -1); - } - - if (size < 0) - return size; - - if (dsb_size < 0) { - /* Found a size, save it. */ - dsb_size = size; - } else { - /* Found duplicate TPDMs */ - return -EEXIST; + rc = tpda_get_element_size(drvdata, in, -1);And then why it's assigned here but not checked for an error in this case?
|Remote ETM| |TPDM|
| branch0 | branch1
--------------------------
funnel1
---------------------------
| input port 1
-----------------------------
TPDA1
-----------------------------
The branches on some TPDA's input ports may not have TPDM. For example, branch 0 doesn't has a
TPDM connected, tpda_get_element_size will not return 0 here. This is a normal situation. We need to
continue to find TPDM on branch1 through recursion.
Maybe some comments explaining the flow would help. Or to me it seems like a second variable to track the thing that's actually intended could be used as well. Like "bool found_element" or something, rather than re-using rc to also track another thing.
Do you prefer to use "static bool found_element" to mark if we already have read an element size in
the recursion function?
} } - return dsb_size; + if ((drvdata->dsb_esize) || (drvdata->cmb_esize)) + rc = 0; + + return rc; } /* Settings pre enabling port control register */ @@ -109,7 +138,7 @@ static void tpda_enable_pre_port(struct tpda_drvdata *drvdata) static int tpda_enable_port(struct tpda_drvdata *drvdata, int port) { u32 val; - int size; + int rc; val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port)); /* @@ -117,29 +146,18 @@ static int tpda_enable_port(struct tpda_drvdata *drvdata, int port) * Set the bit to 0 if the size is 32 * Set the bit to 1 if the size is 64 */ - size = tpda_get_element_size(drvdata->csdev, port); - switch (size) { - case 32: - val &= ~TPDA_Pn_CR_DSBSIZE; - break; - case 64: - val |= TPDA_Pn_CR_DSBSIZE; - break; - case 0: - return -EEXIST; - case -EEXIST: + rc = tpda_get_element_size(drvdata, drvdata->csdev, port); + if (!rc) { + tpda_set_element_size(drvdata, &val); + /* Enable the port */ + val |= TPDA_Pn_CR_ENA; + writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port)); + } else if (rc == -EINVAL) { dev_warn_once(&drvdata->csdev->dev, "Detected multiple TPDMs on port %d", -EEXIST);tpdm_read_element_size() can return EEXIST, but then it gets changed back to EINVAL in tpda_get_element_size() without caring about the specific code, before finally being changed back to EEXIST for the warning here. Can it just be propagated as the original value? Or use EINVAL or EEXIST all the way through. That would probably be easier to follow.
How about if I remove the "else" process, and move the "Detected
multiple TPDMs on port %d"
warning to tpda_get_element_size? In this
way, the warnings of EINVAL or EEXIST will be
printed in tpda_get_element_size
and tpdm_read_element_size.
And then also a comment about why the other possible error values don't result in a warning.
Only EINVAL or EEXIST error values will be returned in the end, right?
Best,
Tao
Thanks James- return -EEXIST; - default: - return -EINVAL; } - /* Enable the port */ - val |= TPDA_Pn_CR_ENA; - writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port)); - - return 0; + return rc; } static int __tpda_enable(struct tpda_drvdata *drvdata, int port) diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h index b3b38fd..29164fd 100644 --- a/drivers/hwtracing/coresight/coresight-tpda.h +++ b/drivers/hwtracing/coresight/coresight-tpda.h @@ -10,6 +10,8 @@ #define TPDA_Pn_CR(n) (0x004 + (n * 4)) /* Aggregator port enable bit */ #define TPDA_Pn_CR_ENA BIT(0) +/* Aggregator port CMB data set element size bit */ +#define TPDA_Pn_CR_CMBSIZE GENMASK(7, 6) /* Aggregator port DSB data set element size bit */ #define TPDA_Pn_CR_DSBSIZE BIT(8) @@ -25,6 +27,8 @@ * @csdev: component vitals needed by the framework. * @spinlock: lock for the drvdata value. * @enable: enable status of the component. + * @dsb_esize Record the DSB element size. + * @cmb_esize Record the CMB element size. */ struct tpda_drvdata { void __iomem *base; @@ -32,6 +36,8 @@ struct tpda_drvdata { struct coresight_device *csdev; spinlock_t spinlock; u8 atid; + u8 dsb_esize; + u8 cmb_esize; }; #endif /* _CORESIGHT_CORESIGHT_TPDA_H */