[PATCH] lib: sbi: Respect boot hart setting in "dynamic" boot mode

[Inochi Amaoto]

In "dynamic" boot mode, the boot hart is only used for the early
initialization, but not for the coldboot even if it is available.
This make the boot hart configuration in the dynamic mode
meaningless.

To solve this, add extra check for coldboot detection and fallback
to the lottery if the boot hart does not support coldboot.

Signed-off-by: Inochi Amaoto <inochiama at outlook.com>
---
 firmware/fw_dynamic.S  |  4 +---
 include/sbi/sbi_init.h |  2 ++
 lib/sbi/sbi_init.c     | 14 +++++++++++++-
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/firmware/fw_dynamic.S b/firmware/fw_dynamic.S
index 5ee2883..c08ba5f 100644
--- a/firmware/fw_dynamic.S
+++ b/firmware/fw_dynamic.S
@@ -66,7 +66,7 @@ fw_save_info:
 	li	a4, FW_DYNAMIC_INFO_VERSION_2
 	REG_L	a3, FW_DYNAMIC_INFO_VERSION_OFFSET(a2)
 	blt	a3, a4, 2f
-	lla	a4, _dynamic_boot_hart
+	lla	a4, sbi_boot_hart
 	REG_L	a3, FW_DYNAMIC_INFO_BOOT_HART_OFFSET(a2)
 	REG_S	a3, (a4)
 2:
@@ -133,5 +133,3 @@ _dynamic_next_mode:
 	RISCV_PTR PRV_S
 _dynamic_options:
 	RISCV_PTR 0x0
-_dynamic_boot_hart:
-	RISCV_PTR -1
diff --git a/include/sbi/sbi_init.h b/include/sbi/sbi_init.h
index 9640fee..dd88c23 100644
--- a/include/sbi/sbi_init.h
+++ b/include/sbi/sbi_init.h
@@ -22,4 +22,6 @@ unsigned long sbi_init_count(u32 hartid);
 
 void __noreturn sbi_exit(struct sbi_scratch *scratch);
 
+extern long sbi_boot_hart;
+
 #endif
diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
index 389172a..70ff4d7 100644
--- a/lib/sbi/sbi_init.c
+++ b/lib/sbi/sbi_init.c
@@ -18,6 +18,7 @@
 #include <sbi/sbi_hartmask.h>
 #include <sbi/sbi_heap.h>
 #include <sbi/sbi_hsm.h>
+#include <sbi/sbi_init.h>
 #include <sbi/sbi_ipi.h>
 #include <sbi/sbi_irqchip.h>
 #include <sbi/sbi_platform.h>
@@ -479,6 +480,8 @@ static void __noreturn init_warmboot(struct sbi_scratch *scratch, u32 hartid)
 
 static atomic_t coldboot_lottery = ATOMIC_INITIALIZER(0);
 
+long sbi_boot_hart = -1;
+
 /**
  * Initialize OpenSBI library for current HART and jump to next
  * booting stage.
@@ -532,9 +535,18 @@ void __noreturn sbi_init(struct sbi_scratch *scratch)
 	 *
 	 * We use a lottery mechanism to select coldboot HART among
 	 * HARTs which satisfy above condition.
+	 *
+	 * If user set the boot HART, we will check whether it supports
+	 * coldboot, and boot the system with the selected one if the
+	 * check success. Otherwise, we fall back to any supported HART
+	 * selected from the lottery mechanism.
 	 */
 
-	if (sbi_platform_cold_boot_allowed(plat, hartid)) {
+	if (sbi_boot_hart != -1 &&
+	    sbi_platform_cold_boot_allowed(plat, sbi_boot_hart)) {
+		if (sbi_boot_hart == hartid)
+			coldboot = true;
+	} else if (sbi_platform_cold_boot_allowed(plat, hartid)) {
 		if (next_mode_supported &&
 		    atomic_xchg(&coldboot_lottery, 1) == 0)
 			coldboot = true;
-- 
2.45.2