diff options
| author | Anshuman Khandual <anshuman.khandual@arm.com> | 2024-04-04 12:59:34 +0530 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2024-05-01 11:12:02 +0100 |
| commit | 8877ef45ef9ec281849870d88039f8dc84cde774 (patch) | |
| tree | c593b063a97f8c2d3caedf6b1cbaa512a7b42d28 /drivers/hwtracing | |
| parent | 2d7e8a64a1e79f76b9d1165db0b92190d4663848 (diff) | |
coresight: tmc: Enable SG capability on ACPI based SoC-400 TMC ETR devices
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>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240404072934.940760-1-anshuman.khandual@arm.com
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-core.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 4b50d043ce04..741ce1748e75 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> @@ -362,7 +363,32 @@ 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) |