[PATCH] lib: sbi: respect scounteren when emulating timeh

[Ben Zong-You Xie]

beef2f693785 ("lib: sbi: Respect scounteren when emulating the time
CSR") restored it for TIME only, so on RV32 supervisor software still
cannot restrict U-mode or VS-mode access to time: rdtime traps as
intended while rdtimeh keeps returning the upper half.

Signed-off-by: Ben Zong-You Xie <ben717 at andestech.com>
---
 lib/sbi/sbi_emulate_csr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/sbi/sbi_emulate_csr.c b/lib/sbi/sbi_emulate_csr.c
index c2253c82c527..4558abffb81a 100644
--- a/lib/sbi/sbi_emulate_csr.c
+++ b/lib/sbi/sbi_emulate_csr.c
@@ -90,7 +90,8 @@ int sbi_emulate_csr_read(int csr_num, struct sbi_trap_regs *regs,
 		*csr_val = csr_read(CSR_MCYCLEH);
 		break;
 	case CSR_TIMEH:
-		/* Refer comments on TIME CSR above. */
+		if (!hpm_allowed(csr_num - CSR_CYCLEH, prev_mode, virt))
+			return SBI_ENOTSUPP;
 		*csr_val = (virt) ? sbi_timer_virt_value() >> 32:
 				    sbi_timer_value() >> 32;
 		break;
-- 
2.34.1