[PATCH v4 2/5] lib: sbi_domain: add sbi_domain_get_oldpmp_flags

[Bo Gan]

Factor out logic in `sbi_hart_oldpmp_configure` into function
`sbi_domain_get_oldpmp_flags`, analogous to `sbi_domain_get_smepmp_flags`.
Platform specific hart-protection implementation can now leverage it.

Signed-off-by: Bo Gan <ganboing at gmail.com>
---
 include/sbi/sbi_domain.h |  7 +++++++
 lib/sbi/sbi_domain.c     | 22 ++++++++++++++++++++++
 lib/sbi/sbi_hart_pmp.c   | 17 +----------------
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/include/sbi/sbi_domain.h b/include/sbi/sbi_domain.h
index 1196d609..3360e090 100644
--- a/include/sbi/sbi_domain.h
+++ b/include/sbi/sbi_domain.h
@@ -253,6 +253,13 @@ void sbi_domain_memregion_init(unsigned long addr,
 				unsigned long flags,
 				struct sbi_domain_memregion *reg);
 
+/**
+ * Return the oldpmp pmpcfg LRWX encoding for the flags in @reg.
+ *
+ * @param reg pointer to memory region; its flags field encodes permissions.
+ */
+unsigned int sbi_domain_get_oldpmp_flags(struct sbi_domain_memregion *reg);
+
 /**
  * Return the Smepmp pmpcfg LRWX encoding for the flags in @reg.
  *
diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
index 99f453f9..1bc64922 100644
--- a/lib/sbi/sbi_domain.c
+++ b/lib/sbi/sbi_domain.c
@@ -121,6 +121,28 @@ void sbi_domain_memregion_init(unsigned long addr,
 	}
 }
 
+unsigned int sbi_domain_get_oldpmp_flags(struct sbi_domain_memregion *reg)
+{
+
+	unsigned int pmp_flags = 0;
+
+	/*
+	 * If permissions are to be enforced for all modes on
+	 * this region, the lock bit should be set.
+	 */
+	if (reg->flags & SBI_DOMAIN_MEMREGION_ENF_PERMISSIONS)
+		pmp_flags |= PMP_L;
+
+	if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
+		pmp_flags |= PMP_R;
+	if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
+		pmp_flags |= PMP_W;
+	if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
+		pmp_flags |= PMP_X;
+
+	return pmp_flags;
+}
+
 unsigned int sbi_domain_get_smepmp_flags(struct sbi_domain_memregion *reg)
 {
 	unsigned int pmp_flags = 0;
diff --git a/lib/sbi/sbi_hart_pmp.c b/lib/sbi/sbi_hart_pmp.c
index 08bc2cef..c9b6850a 100644
--- a/lib/sbi/sbi_hart_pmp.c
+++ b/lib/sbi/sbi_hart_pmp.c
@@ -271,22 +271,7 @@ static int sbi_hart_oldpmp_configure(struct sbi_scratch *scratch)
 		if (!is_valid_pmp_idx(pmp_count, pmp_idx))
 			return SBI_EFAIL;
 
-		pmp_flags = 0;
-
-		/*
-		 * If permissions are to be enforced for all modes on
-		 * this region, the lock bit should be set.
-		 */
-		if (reg->flags & SBI_DOMAIN_MEMREGION_ENF_PERMISSIONS)
-			pmp_flags |= PMP_L;
-
-		if (reg->flags & SBI_DOMAIN_MEMREGION_SU_READABLE)
-			pmp_flags |= PMP_R;
-		if (reg->flags & SBI_DOMAIN_MEMREGION_SU_WRITABLE)
-			pmp_flags |= PMP_W;
-		if (reg->flags & SBI_DOMAIN_MEMREGION_SU_EXECUTABLE)
-			pmp_flags |= PMP_X;
-
+		pmp_flags = sbi_domain_get_oldpmp_flags(reg);
 		pmp_addr = reg->base >> PMP_SHIFT;
 		if (pmp_log2gran <= reg->order && pmp_addr < pmp_addr_max) {
 			sbi_platform_pmp_set(sbi_platform_ptr(scratch),
-- 
2.34.1