From 62790afc9d910936fa19566eb4d7af36587836d5 Mon Sep 17 00:00:00 2001
From: X512 <danger_mail@list.ru>
Date: Sun, 6 Jun 2021 22:42:23 +0900
Subject: [PATCH] kernel/arch/commpage: implement for riscv64

Change-Id: Id7f495896a08a237db85dcedd1174e4c181e373d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4056
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
---
 .../system/arch/riscv64/arch_commpage_defs.h  |  8 +--
 src/system/kernel/arch/riscv64/arch_asm.S     | 10 ++-
 .../kernel/arch/riscv64/arch_commpage.cpp     | 63 ++++++++++++++++++-
 3 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/headers/private/system/arch/riscv64/arch_commpage_defs.h b/headers/private/system/arch/riscv64/arch_commpage_defs.h
index 18f187011f..df081b57e6 100644
--- a/headers/private/system/arch/riscv64/arch_commpage_defs.h
+++ b/headers/private/system/arch/riscv64/arch_commpage_defs.h
@@ -10,9 +10,9 @@
 #       error Must not be included directly. Include <commpage_defs.h> instead!
 #endif
 
-/*
-#define COMMPAGE_ENTRY_RISCV64_SYSCALL (COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 0)
-#define COMMPAGE_ENTRY_RISCV64_MEMCPY  (COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 1)
-*/
+#define COMMPAGE_ENTRY_RISCV64_SIGNAL_HANDLER \
+	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 0)
+#define COMMPAGE_ENTRY_RISCV64_SIGNAL_THREAD_EXIT \
+	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 1)
 
 #endif  /* _SYSTEM_ARCH_RISCV64_COMMPAGE_DEFS_H */
diff --git a/src/system/kernel/arch/riscv64/arch_asm.S b/src/system/kernel/arch/riscv64/arch_asm.S
index d19d713d88..d434dde193 100644
--- a/src/system/kernel/arch/riscv64/arch_asm.S
+++ b/src/system/kernel/arch/riscv64/arch_asm.S
@@ -1,10 +1,11 @@
 /*
- * Copyright 2019, Haiku, Inc. All Rights Reserved
+ * Copyright 2019-2021, Haiku, Inc. All Rights Reserved
  * Distributed under the terms of the MIT License.
  */
 
 
 #include <asm_defs.h>
+#include "syscall_numbers.h"
 
 
 .text
@@ -160,3 +161,10 @@ FUNCTION(arch_longjmp_iframe):
 	mv sp, a0
 	call SVecURet
 FUNCTION_END(arch_longjmp_iframe)
+
+
+FUNCTION(arch_user_thread_exit):
+	li t0, SYSCALL_EXIT_THREAD
+	ecall
+	ret
+FUNCTION_END(arch_user_thread_exit)
diff --git a/src/system/kernel/arch/riscv64/arch_commpage.cpp b/src/system/kernel/arch/riscv64/arch_commpage.cpp
index b7378611ab..e604192902 100644
--- a/src/system/kernel/arch/riscv64/arch_commpage.cpp
+++ b/src/system/kernel/arch/riscv64/arch_commpage.cpp
@@ -13,6 +13,60 @@
 #include <elf.h>
 #include <smp.h>
 
+#include "syscall_numbers.h"
+
+
+extern "C" void arch_user_thread_exit();
+
+typedef void (*SignalHandler)(int signal, siginfo_t* signalInfo,
+	ucontext_t* ctx);
+
+
+extern "C" void
+arch_user_signal_handler(signal_frame_data* data)
+{
+	SignalHandler handler = (SignalHandler)data->handler;
+	handler(data->info.si_signo, &data->info, &data->context);
+
+	#define TO_STRING_LITERAL_HELPER(number)	#number
+	#define TO_STRING_LITERAL(number)	TO_STRING_LITERAL_HELPER(number)
+
+	// _kern_restore_signal_frame(data)
+	asm volatile(
+		"mv a0, %0;"
+		"li t0, " TO_STRING_LITERAL(SYSCALL_RESTORE_SIGNAL_FRAME) ";"
+		"ecall;"
+		:: "r"(data)
+	);
+
+	#undef TO_STRING_LITERAL_HELPER
+	#undef TO_STRING_LITERAL
+}
+
+
+static void
+register_commpage_function(const char* functionName, int32 commpageIndex,
+	const char* commpageSymbolName, addr_t expectedAddress)
+{
+	// get address and size of function
+	elf_symbol_info symbolInfo;
+	if (elf_lookup_kernel_symbol(functionName, &symbolInfo)	!= B_OK) {
+		panic("register_commpage_function(): Failed to find "
+			"signal frame function \"%s\"!", functionName);
+	}
+
+	ASSERT(expectedAddress == symbolInfo.address);
+
+	// fill in the commpage table entry
+	addr_t position = fill_commpage_entry(commpageIndex,
+		(void*)symbolInfo.address, symbolInfo.size);
+
+	// add symbol to the commpage image
+	image_id image = get_commpage_image();
+	elf_add_memory_image_symbol(image, commpageSymbolName, position,
+		symbolInfo.size, B_SYMBOL_TYPE_TEXT);
+}
+
 
 status_t
 arch_commpage_init(void)
@@ -24,6 +78,13 @@ arch_commpage_init(void)
 status_t
 arch_commpage_init_post_cpus(void)
 {
+	register_commpage_function("arch_user_signal_handler",
+		COMMPAGE_ENTRY_RISCV64_SIGNAL_HANDLER, "commpage_signal_handler",
+		(addr_t)&arch_user_signal_handler);
+
+	register_commpage_function("arch_user_thread_exit",
+		COMMPAGE_ENTRY_RISCV64_SIGNAL_THREAD_EXIT, "commpage_thread_exit",
+		(addr_t)&arch_user_thread_exit);
+
 	return B_OK;
 }
-