On 04/04/2024 08:29, Anshuman Khandual wrote:
This detects and enables the scatter gather capability (SG) on ACPI based Soc-400 TMC ETR devices via a new property called 'arm-armhc97c-sg-enable'. The updated ACPI spec can be found below, which contains this new property.
https://developer.arm.com/documentation/den0067/latest/
This preserves current handling for the property 'arm,scatter-gather' both on ACPI and DT based platforms i.e the presence of the property is checked instead of the value.
Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Mike Leach mike.leach@linaro.org Cc: James Clark james.clark@arm.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.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 | 28 ++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 72005b0c633e..2b277499b59a 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -4,6 +4,7 @@
- Description: CoreSight Trace Memory Controller driver
*/ +#include <linux/acpi.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/types.h> @@ -360,7 +361,32 @@ static const struct attribute_group *coresight_etr_groups[] = { static inline bool tmc_etr_can_use_sg(struct device *dev) {
- return fwnode_property_present(dev->fwnode, "arm,scatter-gather");
- int ret;
- u8 val_u8;
- /*
* Presence of the property 'arm,scatter-gather' is checked* on the platform for the feature support, rather than its* value.*/- if (is_of_node(dev->fwnode)) {
return fwnode_property_present(dev->fwnode, "arm,scatter-gather");- } else if (is_acpi_device_node(dev->fwnode)) {
/** TMC_DEVID_NOSCAT test in tmc_etr_setup_caps(), has already ensured* this property is only checked for Coresight SoC 400 TMC configured* as ETR.*/ret = fwnode_property_read_u8(dev->fwnode, "arm-armhc97c-sg-enable", &val_u8);if (!ret)return !!val_u8;if (fwnode_property_present(dev->fwnode, "arm,scatter-gather")) {pr_warn_once("Deprecated ACPI property - arm,scatter-gather\n");return true;}- }
- return false;
} static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata)
Reviewed-by: James Clark james.clark@arm.com