[PATCH 1/5] lib: sbi: Introduce sbi_hart_pmp_unconfigure() function

From: Anup Patel <apatel@ventanamicro.com>
To: Atish Patra <atishp@rivosinc.com>
Cc: Andrew Jones <ajones@ventanamicro.com>,
	Anup Patel <anup@brainfault.org>,
	opensbi@lists.infradead.org, Anup Patel <apatel@ventanamicro.com>
Subject: [PATCH 1/5] lib: sbi: Introduce sbi_hart_pmp_unconfigure() function
Date: Wed, 26 Nov 2025 19:48:40 +0530	[thread overview]
Message-ID: <20251126141845.248697-2-apatel@ventanamicro.com> (raw)
In-Reply-To: <20251126141845.248697-1-apatel@ventanamicro.com>

Currently, the unconfiguring PMP is implemented directly inside
switch_to_next_domain_context() whereas rest of the PMP programming
is done via functions implemented in sbi_hart.c.

Introduce a separate sbi_hart_pmp_unconfigure() function so that
all PMP programming is in one place.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 include/sbi/sbi_hart.h       |  1 +
 lib/sbi/sbi_domain_context.c | 10 +---------
 lib/sbi/sbi_hart.c           | 14 ++++++++++++++
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
index e66dd52f..93682880 100644
--- a/include/sbi/sbi_hart.h
+++ b/include/sbi/sbi_hart.h
@@ -148,6 +148,7 @@ unsigned int sbi_hart_pmp_addrbits(struct sbi_scratch *scratch);
 unsigned int sbi_hart_mhpm_bits(struct sbi_scratch *scratch);
 bool sbi_hart_smepmp_is_fw_region(unsigned int pmp_idx);
 int sbi_hart_pmp_configure(struct sbi_scratch *scratch);
+void sbi_hart_pmp_unconfigure(struct sbi_scratch *scratch);
 int sbi_hart_map_saddr(unsigned long base, unsigned long size);
 int sbi_hart_unmap_saddr(void);
 int sbi_hart_priv_version(struct sbi_scratch *scratch);
diff --git a/lib/sbi/sbi_domain_context.c b/lib/sbi/sbi_domain_context.c
index 74ad25e8..8cf47323 100644
--- a/lib/sbi/sbi_domain_context.c
+++ b/lib/sbi/sbi_domain_context.c
@@ -102,7 +102,6 @@ static int switch_to_next_domain_context(struct hart_context *ctx,
 	struct sbi_trap_context *trap_ctx;
 	struct sbi_domain *current_dom, *target_dom;
 	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
-	unsigned int pmp_count = sbi_hart_pmp_count(scratch);
 
 	if (!ctx || !dom_ctx || ctx == dom_ctx)
 		return SBI_EINVAL;
@@ -121,14 +120,7 @@ static int switch_to_next_domain_context(struct hart_context *ctx,
 	spin_unlock(&target_dom->assigned_harts_lock);
 
 	/* Reconfigure PMP settings for the new domain */
-	for (int i = 0; i < pmp_count; i++) {
-		/* Don't revoke firmware access permissions */
-		if (sbi_hart_smepmp_is_fw_region(i))
-			continue;
-
-		sbi_platform_pmp_disable(sbi_platform_thishart_ptr(), i);
-		pmp_disable(i);
-	}
+	sbi_hart_pmp_unconfigure(scratch);
 	sbi_hart_pmp_configure(scratch);
 
 	/* Save current CSR context and restore target domain's CSR context */
diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index a91703b4..c5a8d248 100644
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -573,6 +573,20 @@ int sbi_hart_pmp_configure(struct sbi_scratch *scratch)
 	return rc;
 }
 
+void sbi_hart_pmp_unconfigure(struct sbi_scratch *scratch)
+{
+	int i, pmp_count = sbi_hart_pmp_count(scratch);
+
+	for (i = 0; i < pmp_count; i++) {
+		/* Don't revoke firmware access permissions */
+		if (sbi_hart_smepmp_is_fw_region(i))
+			continue;
+
+		sbi_platform_pmp_disable(sbi_platform_ptr(scratch), i);
+		pmp_disable(i);
+	}
+}
+
 int sbi_hart_priv_version(struct sbi_scratch *scratch)
 {
 	struct sbi_hart_features *hfeatures =
-- 
2.43.0


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