start working on irqs

10 files changed, 248 insertions, 19 deletions

diff --git a/include/arch/cpu.h b/include/arch/cpu.h
index d142433..1fd146e 100644
--- a/include/arch/cpu.h
+++ b/include/arch/cpu.h
@@ -1,8 +1,8 @@
 /* SPDX-License-Identifier: copyleft-next-0.3.1 */
 /* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
 
-#ifndef KMI_CPU_H
-#define KMI_CPU_H
+#ifndef KMI_ARCH_CPU_H
+#define KMI_ARCH_CPU_H
 
 /**
  * @file cpu.h
@@ -43,4 +43,4 @@ void cpu_assign(struct tcb *t);
  */
 void cpu_send_ipi(id_t cpu_id);
 
-#endif /* KMI_CPU_H */
+#endif /* KMI_ARCH_CPU_H */
diff --git a/include/arch/irq.h b/include/arch/irq.h
index 72b998e..85a7360 100644
--- a/include/arch/irq.h
+++ b/include/arch/irq.h
@@ -1,8 +1,11 @@
 /* SPDX-License-Identifier: copyleft-next-0.3.1 */
 /* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
 
-#ifndef KMI_IRQ_H
-#define KMI_IRQ_H
+#ifndef KMI_ARCH_IRQ_H
+#define KMI_ARCH_IRQ_H
+
+/** Type for IRQ id. */
+typedef uint_fast32_t irq_t;
 
 /**
  * @file irq.h
@@ -19,16 +22,42 @@
 #endif
 
 /**
- * Initialize IRQ subsystem.
+ * Initialize arch-specific IRQ stuff.
  *
  * @param fdt Global FDT pointer.
  */
-void init_irq(void *fdt);
+void setup_irq(void *fdt);
+
+/**
+ * Activate IRQ for \p id.
+ * Assumes there's one interrupt controller for the whole system, which might be
+ * an oversimplification.
+ *
+ * @param id IRQ id to deactivate.
+ * @return OK on success, non-zero otherwise.
+ */
+stat_t activate_irq(irq_t id);
+
+/**
+ * Deactivates IRQ for \p id.
+ *
+ * @param id IRQ id to deactivate.
+ * @return OK on success, non-zero otherwise.
+ */
+stat_t deactivate_irq(irq_t id);
 
 /** Enable IRQs. */
-void enable_irq();
+void enable_irqs();
 
 /** Disable IRQs. */
-void disable_irq();
+void disable_irqs();
+
+/** Get IRQ to handle.
+ *
+ * @return ID of IRQ to handle.
+ *
+ * @todo what about illegal IRQs due to bug or something?
+ */
+irq_t get_irq();
 
-#endif /* KMI_IRQ_H */
+#endif /* KMI_ARCH_IRQ_H */
diff --git a/include/arch/proc.h b/include/arch/proc.h
index 79b099e..341a2f4 100644
--- a/include/arch/proc.h
+++ b/include/arch/proc.h
@@ -21,6 +21,8 @@
  * Attach argument data to thread.
  *
  * @param t Thread that will run after return.
+ * @param n How many of the arguments to attach. Might micro-optimize some
+ * stuff.
  * @param a Arguments to attach.
  */
 void set_args(struct tcb *t, size_t n, struct sys_ret a);
diff --git a/include/kmi/caps.h b/include/kmi/caps.h
index 078dd3d..2813634 100644
--- a/include/kmi/caps.h
+++ b/include/kmi/caps.h
@@ -34,6 +34,9 @@ enum {
 
 	/** Thread is allowed to access configuration parameters. */
 	CAP_CONF = (1 << 4),
+
+	/** Thread is allowed to request to handle IRQs. */
+	CAP_IRQ = (1 << 5),
 };
 
 /**
diff --git a/include/kmi/ipi.h b/include/kmi/ipi.h
index 4567edb..72b54b9 100644
--- a/include/kmi/ipi.h
+++ b/include/kmi/ipi.h
@@ -29,12 +29,7 @@ bool clear_ipi(struct tcb *t);
  */
 void send_ipi(struct tcb *t);
 
-/**
- * Handle IPI.
- *
- * @param t Thread who was interrupted by IPI.
- * @return Possible arguments to IPI.
- */
-struct sys_ret handle_ipi(struct tcb *t);
+/** Handle IPI. */
+void handle_ipi();
 
 #endif /* KMI_IPI_H */
diff --git a/include/kmi/irq.h b/include/kmi/irq.h
new file mode 100644
index 0000000..ccc654b
--- /dev/null
+++ b/include/kmi/irq.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+
+#ifndef KMI_IRQ_H
+#define KMI_IRQ_H
+
+/**
+ * @file irq.h
+ * Common IRQ handling stuff.
+ */
+
+#include <kmi/tcb.h>
+#include <arch/irq.h>
+
+/**
+ * Initialize IRQ subsystem.
+ *
+ * @param fdt Flattened device tree.
+ */
+void init_irq(void *fdt);
+
+/** Handle irq. */
+void handle_irq();
+
+/**
+ * Register IRQ with thread \p t.
+ *
+ * @param t Thread to register IRQ \p id to.
+ * @param id IRQ id to register to \p t.
+ * @return OK on success, non-zero otherwise.
+ */
+stat_t register_irq(struct tcb *t, irq_t id);
+
+/**
+ * Unregister IRQ with thread \p t.
+ *
+ * @param t Thread to unregister \p id from.
+ * @param id IRQ id to unregister from \p t.
+ * @return OK on success, non-zero otherwise.
+ */
+stat_t unregister_irq(struct tcb *t, irq_t id);
+
+#endif /* KMI_IRQ_H */
diff --git a/include/kmi/panic.h b/include/kmi/panic.h
new file mode 100644
index 0000000..44593a3
--- /dev/null
+++ b/include/kmi/panic.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+
+#ifndef KMI_PANIC_H
+#define KMI_PANIC_H
+
+/**
+ * @file panic.h
+ * Kernel panic handler.
+ */
+
+/**
+ * Call on kernel panic, tries to reboot the system. Failing that, spin.
+ * Ideally registers and kernel state would be printed, but keep things simple
+ * for now.
+ *
+ * @param pc Address where fault occured. Should preferably be in the kernel.
+ * @param addr Possibly associated address.
+ * @param cause Possible error code associated with panic. Page fault, etc.
+ */
+__noreturn void kernel_panic(void *pc, void *addr, long cause);
+
+#endif /* KMI_PANIC_H */
diff --git a/include/kmi/syscalls.h b/include/kmi/syscalls.h
index 8ca6546..79cd692 100644
--- a/include/kmi/syscalls.h
+++ b/include/kmi/syscalls.h
@@ -134,6 +134,10 @@ enum {
 
 	/** Shutdown, reboot, etc. */
 	SYS_POWEROFF,
+
+	/** Request to handle IRQ. */
+	SYS_IRQ_REQ,
+
 	/** @} */
 
 	SYS_NUM,
diff --git a/include/kmi/timer.h b/include/kmi/timer.h
index c0855e4..c1a07a2 100644
--- a/include/kmi/timer.h
+++ b/include/kmi/timer.h
@@ -133,4 +133,6 @@ static inline ticks_t secs_to_ticks(tunit_t secs)
 	return msecs_to_ticks(secs * 1000);
 }
 
+void handle_timer();
+
 #endif /* KMI_TIMER_H */
diff --git a/include/kmi/uapi.h b/include/kmi/uapi.h
index 477e315..891b5f9 100644
--- a/include/kmi/uapi.h
+++ b/include/kmi/uapi.h
@@ -796,6 +796,21 @@ SYSCALL_DECLARE3(clear_cap, tid, off, cap);
  * Shouldn't return at all.
  */
 SYSCALL_DECLARE1(poweroff, type);
+
+/**
+ * Request to handle IRQ.
+ *
+ * @param t Current tcb.
+ * @param id ID if IRQ to handle.
+ * @param b Unused.
+ * @param c Unused.
+ * @param d Unused.
+ * @param e Unused.
+ *
+ * Returns OK on success, non-zero otherwise.
+ * @todo document error codes better.
+ */
+SYSCALL_DECLARE1(irq_req, id);
 /** @} */
 
 /**
@@ -818,32 +833,147 @@ void handle_syscall(sys_arg_t syscall, sys_arg_t a, sys_arg_t b,
 
 #include <arch/proc.h>
 
+/**
+ * Set one argument to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ */
 #define set_args1(t, a) set_args(t, 1, SYS_RET1(a))
+
+/**
+ * Set two arguments to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ */
 #define set_args2(t, a, b) set_args(t, 2, SYS_RET2(a, b))
+
+/**
+ * Set three arguments to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ */
 #define set_args3(t, a, b, c) set_args(t, 3, SYS_RET3(a, b, c))
+
+/**
+ * Set four arguments to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ */
 #define set_args4(t, a, b, c, d) set_args(t, 4, SYS_RET4(a, b, c, d))
+
+/**
+ * Set five arguments to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ * @param e Fifth argument.
+ */
 #define set_args5(t, a, b, c, d, e) set_args(t, 5, SYS_RET5(a, b, c, d, e))
-#define set_args6(t, a, b, c, d, e, f) set_args(t, 6, \
-	                                        SYS_RET6(a, b, c, d, e, f))
 
+/**
+ * Set six arguments to pass to thread when returning to userspace.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ * @param e Fifth argument.
+ * @param f Sixth argument.
+ */
+#define set_args6(t, a, b, c, d, e, f) \
+	set_args(t, 6, SYS_RET6(a, b, c, d, e, f))
+
+/**
+ * Set one argument and return from uapi function.
+ * Essentially a beauty macro and slight micro-optimization, avoiding setting
+ * registers to zero when not required.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ */
 #define return_args1(t, a) \
 	{set_args1(t, a); return;}
 
+/**
+ * Set two arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ */
 #define return_args2(t, a, b) \
 	{set_args2(t, a, b); return;}
 
+/**
+ * Set three arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ */
 #define return_args3(t, a, b, c) \
 	{set_args3(t, a, b, c); return;}
 
+/**
+ * Set four arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ */
 #define return_args4(t, a, b, c, d) \
 	{set_args4(t, a, b, c, d); return;}
 
+/**
+ * Set five arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ * @param e Fifth argument.
+ */
 #define return_args5(t, a, b, c, d, e) \
 	{set_args5(t, a, b, c, d, e); return;}
 
+/**
+ * Set six arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param a First argument.
+ * @param b Second argument.
+ * @param c Third argument.
+ * @param d Fourth argument.
+ * @param e Fifth argument.
+ * @param f Sixth argument.
+ */
 #define return_args6(t, a, b, c, d, e, f) \
 	{set_args6(t, a, b, c, d, e, f); return;}
 
+/**
+ * Set all arguments and return from uapi function.
+ *
+ * @param t Thread whose arguments to set.
+ * @param x Arguments to set.
+ */
 #define return_args(t, x) {set_args((t), 6, (x)); return;}
 
 #endif /* KMI_UAPI_H */