From 6054cda4de2341b9a77ec4421411725f3684006b Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Fri, 10 Jul 2020 00:23:32 +0200
Subject: Add hardware interrupt notification mechanism

This allows privileged userland drivers to get notifications of hardware
interrupts.

Initial work by Zheng Da, reworked by Damien Zammit and myself.

* Makefrag.am (libkernel_a_SOURCES): Add device/intr.c and
device/intr.h.
(include_device_HEADERS): Add include/device/notify.defs and
include/device/notify.h.
* device/dev_hdr.h (name_equal): Add declaration.
* device/ds_routines.c: Include <device/intr.h>
(ds_device_intr_register, ds_device_intr_ack): New functions.
* device/intr.c, device/intr.h: New files.
* doc/mach.texi (Device Interrupt): New section.
* i386/Makefrag.am (libkernel_a_SOURCES): Add i386/i386/irq.c and
i386/i386/irq.h.
* i386/i386/irq.c, i386/i386/irq.h: New files.
* i386/i386at/conf.c: Include <device/intr.h>.
(irqname): New macro.
(dev_name_list): Add irq device.
* include/device/device.defs (device_intr_register, device_intr_ack):
New RPCs.
* include/device/notify.defs, include/device/notify.h: New files.
* kern/startup.c: Include <device/intr.h>
(start_kernel_threads): Start intr_thread thread.
* linux/dev/arch/i386/kernel/irq.c: Include <device/intr.h>
(linux_action): Add user_intr field.
(linux_intr): Call user_intr action if any.
(mask_irq, unmask_irq): Move functions to i386/i386/pic.c
(__disable_irq, __enable_irq): Move functions to i386/i386/irq.c.
(install_user_intr_handler): New function.
(request_irq): Initialize user_intr field.
* linux/src/include/asm-i386/irq.h (__disable_irq, __enable_irq): Remove
prototypes.
* i386/i386/pic.c (mask_irq, unmask_irq): New functions.
* i386/i386/pic.h (mask_irq, unmask_irq): New prototypes.
---
 device/ds_routines.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

(limited to 'device/ds_routines.c')

diff --git a/device/ds_routines.c b/device/ds_routines.c
index fc051e8f..78ff51fe 100644
--- a/device/ds_routines.c
+++ b/device/ds_routines.c
@@ -92,6 +92,7 @@
 #include <device/device_port.h>
 #include <device/device_reply.user.h>
 #include <device/device_emul.h>
+#include <device/intr.h>
 
 #include <machine/machspl.h>
 
@@ -319,6 +320,59 @@ ds_device_map (device_t dev, vm_prot_t prot, vm_offset_t offset,
 				offset, size, pager, unmap);
 }
 
+/* TODO: missing deregister support */
+io_return_t
+ds_device_intr_register (device_t dev, int id,
+                         int flags, ipc_port_t receive_port)
+{
+  kern_return_t err;
+  mach_device_t mdev = dev->emul_data;
+
+  /* Refuse if device is dead or not completely open.  */
+  if (dev == DEVICE_NULL)
+    return D_NO_SUCH_DEVICE;
+
+  /* No flag is defined for now */
+  if (flags != 0)
+    return D_INVALID_OPERATION;
+
+  /* Must be called on the irq device only */
+  if (! name_equal(mdev->dev_ops->d_name, 3, "irq"))
+    return D_INVALID_OPERATION;
+
+  user_intr_t *e = insert_intr_entry (&irqtab, id, receive_port);
+  if (!e)
+    return D_NO_MEMORY;
+
+  // TODO The original port should be replaced
+  // when the same device driver calls it again,
+  // in order to handle the case that the device driver crashes and restarts.
+  err = install_user_intr_handler (&irqtab, id, flags, e);
+  if (err == D_SUCCESS)
+    {
+      /* If the port is installed successfully, increase its reference by 1.
+       * Thus, the port won't be destroyed after its task is terminated. */
+      ip_reference (receive_port);
+    }
+  return err;
+}
+
+kern_return_t
+ds_device_intr_ack (device_t dev, ipc_port_t receive_port)
+{
+  mach_device_t mdev = dev->emul_data;
+
+  /* Refuse if device is dead or not completely open.  */
+  if (dev == DEVICE_NULL)
+    return D_NO_SUCH_DEVICE;
+
+  /* Must be called on the irq device only */
+  if (! name_equal(mdev->dev_ops->d_name, 3, "irq"))
+    return D_INVALID_OPERATION;
+
+  return irq_acknowledge(receive_port);
+}
+
 boolean_t
 ds_notify (mach_msg_header_t *msg)
 {
-- 
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