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authorSudeep Holla <sudeep.holla@arm.com>2022-02-03 22:01:59 +0300
committerSuzuki K Poulose <suzuki.poulose@arm.com>2022-03-11 13:07:43 +0300
commitef1dacf4b3e23dae57d741bb592a3393428c5a7d (patch)
treed71ba927f803f46e478b772ae3fc5c92b2bb64f0
parentd05bbad0130ff86b802e5cd6acbb6cac23b841b8 (diff)
downloadlinux-ef1dacf4b3e23dae57d741bb592a3393428c5a7d.tar.xz
coresight: trbe: Move check for kernel page table isolation from EL0 to probe
Currently with the check present in the module initialisation, it shouts on all the systems irrespective of presence of coresight trace buffer extensions. Similar to Arm SPE perf driver, move the check for kernel page table isolation from EL0 to the device probe stage instead of the module initialisation so that it complains only on the systems that support TRBE. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: coresight@lists.linaro.org Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20220203190159.3145272-1-sudeep.holla@arm.com Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
-rw-r--r--drivers/hwtracing/coresight/coresight-trbe.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 75b608bc400b..2b386bb848f8 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1481,6 +1481,12 @@ static int arm_trbe_device_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
int ret;
+ /* Trace capture is not possible with kernel page table isolation */
+ if (arm64_kernel_unmapped_at_el0()) {
+ pr_err("TRBE wouldn't work if kernel gets unmapped at EL0\n");
+ return -EOPNOTSUPP;
+ }
+
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
@@ -1542,11 +1548,6 @@ static int __init arm_trbe_init(void)
{
int ret;
- if (arm64_kernel_unmapped_at_el0()) {
- pr_err("TRBE wouldn't work if kernel gets unmapped at EL0\n");
- return -EOPNOTSUPP;
- }
-
ret = platform_driver_register(&arm_trbe_driver);
if (!ret)
return 0;