[PATCH 3/8] lib: sbi_domain: print unsupported SmePMP permissions

[Yu-Chien Peter Lin]

The reg->flag is encoded with 6 bits to specify RWX
permissions for M-mode and S-/U-mode. However, only 16
of the possible encodings are valid on SmePMP.

Previously, specifying an unsupported encoding could fail
silently. Add a warning log when an unsupported permission
encoding is detected, improving visibility for debugging.

Signed-off-by: Yu-Chien Peter Lin <peter.lin at sifive.com>
---
 lib/sbi/sbi_domain.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
index e8adf66f..d6566b12 100644
--- a/lib/sbi/sbi_domain.c
+++ b/lib/sbi/sbi_domain.c
@@ -125,6 +125,7 @@ void sbi_domain_memregion_init(unsigned long addr,
 unsigned int sbi_domain_get_smepmp_flags(struct sbi_domain_memregion *reg)
 {
 	unsigned int pmp_flags = 0;
+	unsigned long rstart, rend;
 
 	if ((reg->flags & SBI_DOMAIN_MEMREGION_ACCESS_MASK) == 0) {
 		/*
@@ -186,6 +187,13 @@ unsigned int sbi_domain_get_smepmp_flags(struct sbi_domain_memregion *reg)
 			pmp_flags |= PMP_W;
 		if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
 			pmp_flags |= PMP_X;
+	} else {
+		rstart = reg->base;
+		rend = (reg->order < __riscv_xlen) ?
+			rstart + ((1UL << reg->order) - 1) : -1UL;
+		sbi_printf("%s: Unsupported Smepmp permissions "
+			   "on region 0x%" PRILX "-0x%" PRILX "\n",
+			   __func__, rstart, rend);
 	}
 
 	return pmp_flags;
-- 
2.39.3