From 312703104d20c8b737c672f755abadfbceb8b50e Mon Sep 17 00:00:00 2001
From: Edgaru089 <sjs333@outlook.com>
Date: Sun, 7 Nov 2021 23:05:29 +0800
Subject: [PATCH] driver/pic: IRQHandlerRaw jumped handler

---
 driver/irq/pic/int_handler.asm.S | 23 +++++++++++++++++++++--
 driver/irq/pic/pic.h             |  5 +++++
 driver/irq/pic/pic_init.c        |  2 ++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/driver/irq/pic/int_handler.asm.S b/driver/irq/pic/int_handler.asm.S
index c434431..d42215e 100644
--- a/driver/irq/pic/int_handler.asm.S
+++ b/driver/irq/pic/int_handler.asm.S
@@ -1,6 +1,9 @@
 format elf64
 
+include 'pic_constants.incS'
+
 extrn irq_pic_IntHandler
+extrn irq_pic_IRQHandlerRaw
 
 public irq_pic_IntHandler20h
 public irq_pic_IntHandler21h
@@ -23,9 +26,25 @@ public irq_pic_IntHandler2fh
 section '.text' executable
 
 macro inth op1 {
+	push rax
+
+	mov  rax, [irq_pic_IRQHandlerRaw+op1*8]
+	test rax, rax
+	jz .noraw
+
+	; has raw handler
+	mov al, PIC_CMD_EOI
+	if op1 >= 8
+		out PIC2_COMMAND, al
+	end if
+	out PIC1_COMMAND, al
+
+	pop rax
+	jmp qword [irq_pic_IRQHandlerRaw+op1*8]
+
+.noraw:
 	push rdi
 	mov rdi, op1
-	push rax
 	push rsi
 	push rdx
 	push rcx
@@ -41,8 +60,8 @@ macro inth op1 {
 	pop rcx
 	pop rdx
 	pop rsi
-	pop rax
 	pop rdi
+	pop rax
 	iretq
 }
 
diff --git a/driver/irq/pic/pic.h b/driver/irq/pic/pic.h
index 20159ce..ddddbd4 100644
--- a/driver/irq/pic/pic.h
+++ b/driver/irq/pic/pic.h
@@ -36,6 +36,11 @@ typedef SYSV_ABI void (*irq_pic_IRQHandlerType)();
 extern irq_pic_IRQHandlerType irq_pic_IRQHandler[16];
 extern bool                   irq_pic_Enabled;
 
+// If IRQHandlerRaw[irq] is not NULL, the function is jumped to (not called).
+//
+// So the handler should use IRET instead of RET, and save all the registers it uses.
+extern void *irq_pic_IRQHandlerRaw[16];
+
 
 #ifdef __cplusplus
 }
diff --git a/driver/irq/pic/pic_init.c b/driver/irq/pic/pic_init.c
index 3be6104..cbcdbc9 100644
--- a/driver/irq/pic/pic_init.c
+++ b/driver/irq/pic/pic_init.c
@@ -10,6 +10,7 @@
 
 
 irq_pic_IRQHandlerType irq_pic_IRQHandler[16];
+void *                 irq_pic_IRQHandlerRaw[16];
 bool                   irq_pic_Enabled;
 
 void irq_pic_Init() {
@@ -34,6 +35,7 @@ void irq_pic_Init() {
 	outb_wait(PIC2_DATA, 0xff);
 
 	memset(irq_pic_IRQHandler, 0, sizeof(irq_pic_IRQHandler)); // reset all IRQ handlers
+	memset(irq_pic_IRQHandlerRaw, 0, sizeof(irq_pic_IRQHandlerRaw));
 
 	// map the IRQ handlers
 	interrupt_MapHandler(irq_pic_IntHandler20h, 0x20);