From b8ecf7075b96b281ff837cf3612316733a6f7dbf Mon Sep 17 00:00:00 2001
From: Pawel Wieczorkiewicz <wipawel@amazon.de>
Date: Fri, 6 Aug 2021 13:21:56 +0200
Subject: [PATCH] acpica: add interrupt handling functionality to OSL

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
---
 arch/x86/entry.S          |  5 +++-
 drivers/acpi/acpica/osl.c | 63 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/arch/x86/entry.S b/arch/x86/entry.S
index 6b508885..63a93f3f 100644
--- a/arch/x86/entry.S
+++ b/arch/x86/entry.S
@@ -93,6 +93,9 @@ END_FUNC(handle_exception)
 interrupt_handler timer timer_interrupt_handler
 interrupt_handler uart uart_interrupt_handler
 interrupt_handler keyboard keyboard_interrupt_handler
+#ifdef KTF_ACPICA
+interrupt_handler acpi acpi_interrupt_handler
+#endif
 
 ENTRY(usermode_call_asm)
     /* FIXME: Add 32-bit support */
@@ -142,4 +145,4 @@ ENTRY(rmode_exception)
 .Lhalt_loop:
     hlt
     jmp .Lhalt_loop
-END_FUNC(rmode_exception)
\ No newline at end of file
+END_FUNC(rmode_exception)
diff --git a/drivers/acpi/acpica/osl.c b/drivers/acpi/acpica/osl.c
index 19f74261..2ea008b3 100644
--- a/drivers/acpi/acpica/osl.c
+++ b/drivers/acpi/acpica/osl.c
@@ -25,8 +25,10 @@
 #ifdef KTF_ACPICA
 #include <ktf.h>
 #include <mm/slab.h>
+#include <percpu.h>
 #include <sched.h>
 #include <semaphore.h>
+#include <setup.h>
 #include <smp/smp.h>
 #include <spinlock.h>
 #include <time.h>
@@ -365,4 +367,65 @@ UINT64 AcpiOsGetTimer(void) { return get_timer_ticks(); }
 
 /* FIXME: Use microseconds granularity */
 void AcpiOsStall(UINT32 Microseconds) { msleep(1); }
+
+/* ACPI interrupt handling functions */
+
+extern void asm_interrupt_handler_acpi(void);
+static bool acpi_irq_installed = false;
+static uint32_t acpi_irq_num;
+static ACPI_OSD_HANDLER acpi_irq_handler = NULL;
+static void *acpi_irq_context = NULL;
+static bool acpi_irq_handled = false;
+
+void acpi_interrupt_handler(void) {
+    uint32_t ret = acpi_irq_handler(acpi_irq_context);
+
+    if (ret == ACPI_INTERRUPT_HANDLED)
+        acpi_irq_handled = true;
+    else if (ret == ACPI_INTERRUPT_NOT_HANDLED)
+        acpi_irq_handled = false;
+}
+
+ACPI_STATUS AcpiOsInstallInterruptHandler(UINT32 InterruptLevel, ACPI_OSD_HANDLER Handler,
+                                          void *Context) {
+    percpu_t *percpu = get_percpu_page(get_bsp_cpu_id());
+
+    if (acpi_irq_installed)
+        return AE_ALREADY_EXISTS;
+
+    if (!Handler || InterruptLevel > ARRAY_SIZE(idt))
+        return AE_BAD_PARAMETER;
+
+    acpi_irq_num = InterruptLevel;
+    acpi_irq_handler = Handler;
+    acpi_irq_context = Context;
+
+    set_intr_gate(&percpu->idt[acpi_irq_num], __KERN_CS, _ul(asm_interrupt_handler_acpi),
+                  GATE_DPL0, GATE_PRESENT, 1);
+    barrier();
+
+    acpi_irq_installed = true;
+    return AE_OK;
+}
+
+ACPI_STATUS AcpiOsRemoveInterruptHandler(UINT32 InterruptLevel,
+                                         ACPI_OSD_HANDLER Handler) {
+    percpu_t *percpu = get_percpu_page(get_bsp_cpu_id());
+
+    if (!acpi_irq_installed)
+        return AE_NOT_EXIST;
+
+    if (!Handler || InterruptLevel > ARRAY_SIZE(idt) || InterruptLevel != acpi_irq_num)
+        return AE_BAD_PARAMETER;
+
+    if (Handler != _ptr(get_intr_handler(&percpu->idt[acpi_irq_num])))
+        return AE_BAD_PARAMETER;
+
+    set_intr_gate(&percpu->idt[acpi_irq_num], __KERN_CS, _ul(NULL), GATE_DPL0,
+                  GATE_NOT_PRESENT, 0);
+    barrier();
+
+    acpi_irq_installed = false;
+    return AE_OK;
+}
 #endif /* KTF_ACPICA */