dev/block: Add NVMe driver

lib/irq.c

@@ -5,6 +5,8 @@
 #include <zinnia/list.h>
 #include <zinnia/percpu.h>
 #include <zinnia/print.h>
+#include <zinnia/sched.h>
+#include <zinnia/utils.h>
 #include <arch/cpu.h>
 #include <arch/irq.h>
 
@@ -39,9 +41,43 @@ void irq_unlock() {
 void irq_line_program(struct irq_line* line, enum irq_trigger_mode trigger, enum irq_polarity polarity) {
     irq_lock();
     line->mode = line->set_config(line, trigger, polarity);
+    line->trigger = trigger;
     irq_unlock();
 }
 
+static bool holds_mask_while_threaded(struct irq_line* line) {
+    return line->trigger == IRQ_TRIGGER_LEVEL && (line->mode & IRQ_MODE_MASKABLE) && line->mask && line->unmask;
+}
+
+static void wake_thread(struct irq_line* line, struct irq_handler* handler) {
+    if (holds_mask_while_threaded(line)) {
+        spin_lock(&line->thread_lock);
+        if (!handler->holds_mask) {
+            handler->holds_mask = true;
+            if (line->threads_pending++ == 0)
+                line->mask(line);
+        }
+        spin_unlock(&line->thread_lock);
+    }
+
+    work_queue(handler->wq, &handler->work);
+}
+
+static void irq_thread_work(struct work* work) {
+    struct irq_handler* handler = containerof(work, struct irq_handler, work);
+    struct irq_line* line = handler->line;
+
+    handler->thread(handler);
+
+    spin_lock(&line->thread_lock);
+    if (handler->holds_mask) {
+        handler->holds_mask = false;
+        if (--line->threads_pending == 0)
+            line->unmask(line);
+    }
+    spin_unlock(&line->thread_lock);
+}
+
 void irq_line_raise(struct irq_line* line) {
     assert(!arch_irq_get_state(), "Raised an IRQ line with interrupts enabled");
 
@@ -51,8 +87,13 @@ void irq_line_raise(struct irq_line* line) {
     bool claimed = false;
     struct irq_handler* handler;
     list_foreach(handler, &line->handlers, next) {
-        if (handler->raise(handler) == IRQ_STATUS_HANDLED)
+        enum irq_status status = handler->raise ? handler->raise(handler) : IRQ_STATUS_WAKE_THREAD;
+        if (status == IRQ_STATUS_WAKE_THREAD && handler->wq) {
+            wake_thread(line, handler);
             claimed = true;
+        } else if (status != IRQ_STATUS_IGNORED) {
+            claimed = true;
+        }
     }
 
     if (!claimed)
@@ -83,3 +124,21 @@ void irq_line_detach(struct irq_line* line, struct irq_handler* handler) {
     while (__atomic_load_n(&line->is_busy, __ATOMIC_ACQUIRE))
         arch_cpu_pause();
 }
+
+errno_t irq_line_attach_threaded(struct irq_line* line, struct irq_handler* handler, const char* name) {
+    if (!handler->thread)
+        return EINVAL;
+
+    char task_name[TASK_NAME_MAX];
+    ksnprintf(task_name, sizeof(task_name), "irq/%s", name);
+
+    handler->line = line;
+    work_init(&handler->work, irq_thread_work);
+    handler->holds_mask = false;
+    errno_t status = workqueue_create(task_name, SCHED_PRIO_IRQ, &handler->wq);
+    if (status)
+        return status;
+
+    irq_line_attach(line, handler);
+    return 0;
+}