[PATCH RFC bpf-next 1/2] selftests/bpf: Add riscv support for get_preempt_count()

[Tiezhu Yang]

There is no riscv support for get_preempt_count() currently and its
fallback path always returns 0, just add it so that bpf_in_interrupt(),
bpf_in_nmi(), bpf_in_hardirq(), bpf_in_serving_softirq(), bpf_in_task()
works for riscv as well. With this patch, "./test_progs -t exe_ctx"
should pass on riscv.

Signed-off-by: Tiezhu Yang <yangtiezhu at loongson.cn>
---
 tools/testing/selftests/bpf/bpf_experimental.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h
index 2234bd6bc9d3..e5c039bc44cb 100644
--- a/tools/testing/selftests/bpf/bpf_experimental.h
+++ b/tools/testing/selftests/bpf/bpf_experimental.h
@@ -505,6 +505,8 @@ static inline int get_preempt_count(void)
 	return bpf_get_current_task_btf()->thread_info.preempt_count;
 #elif defined(bpf_target_s390)
 	return bpf_get_lowcore()->preempt_count;
+#elif defined(bpf_target_riscv)
+	return bpf_get_current_task_btf()->thread_info.preempt_count;
 #endif
 	return 0;
 }
@@ -515,6 +517,7 @@ static inline int get_preempt_count(void)
  *	* arm64
  *	* powerpc64
  *	* s390x
+ *	* riscv
  */
 static inline int bpf_in_interrupt(void)
 {
@@ -536,6 +539,7 @@ static inline int bpf_in_interrupt(void)
  *	* arm64
  *	* powerpc64
  *	* s390x
+ *	* riscv
  */
 static inline int bpf_in_nmi(void)
 {
@@ -548,6 +552,7 @@ static inline int bpf_in_nmi(void)
  *	* arm64
  *	* powerpc64
  *	* s390x
+ *	* riscv
  */
 static inline int bpf_in_hardirq(void)
 {
@@ -560,6 +565,7 @@ static inline int bpf_in_hardirq(void)
  *	* arm64
  *	* powerpc64
  *	* s390x
+ *	* riscv
  */
 static inline int bpf_in_serving_softirq(void)
 {
@@ -580,6 +586,7 @@ static inline int bpf_in_serving_softirq(void)
  *	* arm64
  *	* powerpc64
  *	* s390x
+ *	* riscv
  */
 static inline int bpf_in_task(void)
 {
-- 
2.42.0