[PATCH 1/4] lib: sbi: domain: ensure boot_hartid is assigned

[dave.patel at riscstar.com]

From: Raymond Mao <raymond.mao at riscstar.com>

When boot_hartid points to a hart that is not in the domain's assigned
hartmask (e.g. due to cold boot hart differences), the domain startup
can skip starting the intended boot hart, leading to intermittent Linux
boot failures. Scan the assigned hartmask and pick the first available
hartid to guarantee a valid boot target.
---
 lib/sbi/sbi_domain.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/lib/sbi/sbi_domain.c b/lib/sbi/sbi_domain.c
index 4e8d2045..498a1d56 100644
--- a/lib/sbi/sbi_domain.c
+++ b/lib/sbi/sbi_domain.c
@@ -804,6 +804,30 @@ int sbi_domain_startup(struct sbi_scratch *scratch, u32 cold_hartid)
 
 	/* Startup boot HART of domains */
 	sbi_domain_for_each(dom) {
+		u32 boot_hartindex = sbi_hartid_to_hartindex(dom->boot_hartid);
+		bool boot_assigned = false;
+
+		if (sbi_hartindex_valid(boot_hartindex)) {
+			spin_lock(&dom->assigned_harts_lock);
+			boot_assigned = sbi_hartmask_test_hartindex(
+				boot_hartindex, &dom->assigned_harts);
+			spin_unlock(&dom->assigned_harts_lock);
+		}
+
+		if (!boot_assigned) {
+			u32 new_hartid = -1U;
+
+			spin_lock(&dom->assigned_harts_lock);
+			sbi_hartmask_for_each_hartindex(dhart, &dom->assigned_harts) {
+				new_hartid = sbi_hartindex_to_hartid(dhart);
+				break;
+			}
+			spin_unlock(&dom->assigned_harts_lock);
+
+			if (new_hartid != -1U)
+				dom->boot_hartid = new_hartid;
+		}
+
 		/* Domain boot HART index */
 		dhart = sbi_hartid_to_hartindex(dom->boot_hartid);
 
-- 
2.43.0