From 026c8b9c040966d5ccfbae23bac19eddc040c8d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Thu, 10 Sep 2020 22:16:56 +0200
Subject: [PATCH] kernel/smp: add call_single_cpu()
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to call a function on the target cpu. Early mechanism not available.

Change-Id: I9d049e618c319c59729d1ab53fb313b748f82315
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3212
Reviewed-by: Axel Dörfler <axeld@pinc-software.de>
---
 headers/private/kernel/smp.h |  5 +++++
 src/system/kernel/smp.cpp    | 39 ++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/headers/private/kernel/smp.h b/headers/private/kernel/smp.h
index dc45086792..d88e4206bc 100644
--- a/headers/private/kernel/smp.h
+++ b/headers/private/kernel/smp.h
@@ -91,6 +91,11 @@ int32 smp_get_current_cpu(void);
 
 int smp_intercpu_int_handler(int32 cpu);
 
+void call_single_cpu(uint32 targetCPU, void (*func)(void*, int), void* cookie);
+void call_single_cpu_sync(uint32 targetCPU, void (*func)(void*, int),
+	void* cookie);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/system/kernel/smp.cpp b/src/system/kernel/smp.cpp
index e949a50c1f..ed259d38ae 100644
--- a/src/system/kernel/smp.cpp
+++ b/src/system/kernel/smp.cpp
@@ -1489,6 +1489,45 @@ smp_get_current_cpu(void)
 }
 
 
+static void
+_call_single_cpu(uint32 targetCPU, void (*func)(void*, int), void* cookie, bool sync)
+{
+	cpu_status state = disable_interrupts();
+
+	if (targetCPU == (uint32)smp_get_current_cpu()) {
+		func(cookie, smp_get_current_cpu());
+		restore_interrupts(state);
+		return;
+	}
+
+	if (!sICIEnabled) {
+		// Early mechanism not available
+		panic("call_single_cpu is not yet available");
+		restore_interrupts(state);
+		return;
+	}
+
+	smp_send_ici(targetCPU, SMP_MSG_CALL_FUNCTION, (addr_t)cookie,
+		0, 0, (void*)func, sync ? SMP_MSG_FLAG_SYNC : SMP_MSG_FLAG_ASYNC);
+
+	restore_interrupts(state);
+}
+
+
+void
+call_single_cpu(uint32 targetCPU, void (*func)(void*, int), void* cookie)
+{
+	return _call_single_cpu(targetCPU, func, cookie, false);
+}
+
+
+void
+call_single_cpu_sync(uint32 targetCPU, void (*func)(void*, int), void* cookie)
+{
+	return _call_single_cpu(targetCPU, func, cookie, true);
+}
+
+
 // #pragma mark - public exported functions