Change in coreboot[master]: src/cpu/x86: Add helper mp_run_on_all_aps

[Aamir Bohra (Code Review)]

Aamir Bohra has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/51271 )

Change subject: src/cpu/x86: Add helper mp_run_on_all_aps
......................................................................

src/cpu/x86: Add helper mp_run_on_all_aps

Add a helper function mp_run_on_all_aps, it allows running a given
func on all APs excluding the BSP, with an added provison to run
func in serial manner per AP.

BUG=b:169114674

Signed-off-by: Aamir Bohra 
Change-Id: I74ee8168eb6380e346590f2575350e0a6b73856e
---
M src/cpu/x86/mp_init.c
M src/include/cpu/x86/mp.h
2 files changed, 20 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/71/51271/1

diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c
index cca6093..1960d93 100644
--- a/src/cpu/x86/mp_init.c
+++ b/src/cpu/x86/mp_init.c
@@ -992,6 +992,23 @@
    return run_ap_work(&lcb, expire_us);
 }

+int mp_run_on_all_aps(void (*func)(void *), void *arg, long expire_us, bool run_serial)
+{
+	const int bsp_index = cpu_index();
+	if (run_serial) {
+		for (int ap_index = 0; ap_index <= global_num_aps; ap_index++) {
+			/* skip if BSP */
+			if (ap_index == bsp_index)
+				continue;
+			if (mp_run_on_aps(func, arg, ap_index, expire_us))
+				return -1;
+		}
+	} else { /* Run parallel on all APs */
+		return mp_run_on_aps(func, arg, 0, expire_us);
+	}
+	return 0;
+}
+
 int mp_run_on_all_cpus(void (*func)(void *), void *arg)
 {
    /* Run on BSP first. */
diff --git a/src/include/cpu/x86/mp.h b/src/include/cpu/x86/mp.h
index b2704eb..d97958d 100644
--- a/src/include/cpu/x86/mp.h
+++ b/src/include/cpu/x86/mp.h
@@ -125,6 +125,9 @@
 int mp_run_on_aps(void (*func)(void *), void *arg, int logical_cpu_num,
    	long expire_us);

+/* Runs func on all APs excluding BSP, with a provision to run calls serially per AP */
+int mp_run_on_all_aps(void (*func)(void *), void *arg, long expire_us, bool run_serial);
+
 /* Like mp_run_on_aps() but also runs func on BSP. */
 int mp_run_on_all_cpus(void (*func)(void *), void *arg);