kernel: add equeue object

equeue is a way for the kernel to deliver events to userspace programs.

include/kernel/equeue.h

@@ -0,0 +1,34 @@
+#ifndef KERNEL_EQUEUE_H_
+#define KERNEL_EQUEUE_H_
+
+#include <kernel/locks.h>
+#include <kernel/object.h>
+#include <kernel/sched.h>
+#include <mango/types.h>
+
+#define EQUEUE_PACKET_MAX 100
+
+enum equeue_flags {
+	EQUEUE_WAIT,
+	EQUEUE_DISCARD,
+};
+
+struct equeue {
+	struct object eq_base;
+	unsigned short eq_read_ptr, eq_write_ptr;
+	equeue_packet_t eq_packets[EQUEUE_PACKET_MAX];
+	struct waitqueue eq_wq;
+};
+
+extern kern_status_t equeue_type_init(void);
+extern struct equeue *equeue_cast(struct object *obj);
+
+extern struct equeue *equeue_create(void);
+
+extern kern_status_t equeue_enqueue(
+	struct equeue *q,
+	const equeue_packet_t *pkt,
+	enum equeue_flags flags);
+extern kern_status_t equeue_dequeue(struct equeue *q, equeue_packet_t *out);
+
+#endif

kernel/equeue.c

@@ -0,0 +1,29 @@
+#include <kernel/equeue.h>
+
+kern_status_t equeue_type_init(void)
+{
+	return KERN_UNIMPLEMENTED;
+}
+
+struct equeue *equeue_cast(struct object *obj)
+{
+	return NULL;
+}
+
+struct equeue *equeue_create(void)
+{
+	return NULL;
+}
+
+kern_status_t equeue_enqueue(
+	struct equeue *q,
+	const equeue_packet_t *pkt,
+	enum equeue_flags flags)
+{
+	return KERN_UNIMPLEMENTED;
+}
+
+kern_status_t equeue_dequeue(struct equeue *q, equeue_packet_t *out)
+{
+	return KERN_UNIMPLEMENTED;
+}

libmango/include-user/mango/equeue.h

@@ -0,0 +1,9 @@
+#ifndef MANGO_EQUEUE_H_
+#define MANGO_EQUEUE_H_
+
+#include <mango/types.h>
+
+extern kern_status_t equeue_create(kern_handle_t *out);
+extern kern_status_t equeue_dequeue(kern_handle_t eq, equeue_packet_t *out);
+
+#endif

libmango/include/mango/types.h

@@ -18,11 +18,31 @@
 #define KERN_CFG_INVALID        0x00u
 #define KERN_CFG_PAGE_SIZE      0x01u
 
+/* maximum number of handles that can be sent in a single message */
 #define KERN_MSG_MAX_HANDLES    64
+
+/* the corresponding handle should be ignored */
 #define KERN_MSG_HANDLE_IGNORE  0
+/* the corresponding handle should be moved to the recipient task. the handle
+ * will be closed. */
 #define KERN_MSG_HANDLE_MOVE    1
+/* the corresponding handle should be copied to the recipient task. the handle
+ * will remain valid for the sending task. */
 #define KERN_MSG_HANDLE_COPY    2
 
+/* maximum number of objects that can be waited on in a single call to
+ * kern_object_wait */
+#define KERN_WAIT_MAX_ITEMS     64
+
+/* equeue packet types */
+#define EQUEUE_PKT_PAGE_REQUEST 0x01u
+#define EQUEUE_PKT_ASYNC_SIGNAL 0x02u
+
+/* page request types */
+#define PAGE_REQUEST_READ       0x01u
+#define PAGE_REQUEST_DIRTY      0x02u
+#define PAGE_REQUEST_DETACH     0x03u
+
 #define IOVEC(p, len)                                                          \
 	{                                                                      \
 		.io_base = (virt_addr_t)(p),                                   \
@@ -46,13 +66,17 @@ typedef uintptr_t virt_addr_t;
 typedef uint64_t msgid_t;
 typedef uint64_t off_t;
 typedef uint64_t koid_t;
+typedef uintptr_t equeue_key_t;
 typedef unsigned int tid_t;
+typedef unsigned int vm_controller_packet_type_t;
 typedef unsigned int kern_status_t;
 typedef uint32_t kern_handle_t;
 typedef uint32_t kern_config_key_t;
 typedef uint32_t vm_prot_t;
 typedef int64_t ssize_t;
 
+typedef unsigned short equeue_packet_type_t;
+
 typedef unsigned int umode_t;
 
 typedef struct {
@@ -60,6 +84,12 @@ typedef struct {
 	size_t io_len;
 } kern_iovec_t;
 
+typedef struct {
+	kern_handle_t w_handle;
+	uint32_t w_waitfor;
+	uint32_t w_observed;
+} kern_wait_item_t;
+
 typedef struct {
 	unsigned int hnd_mode;
 	kern_handle_t hnd_value;
@@ -84,4 +114,36 @@ typedef struct {
 	size_t msg_handles_count;
 } kern_msg_t;
 
+typedef struct {
+	uint32_t s_observed;
+} equeue_packet_async_signal_t;
+
+typedef struct {
+	/* the key of the vm-object for which the page request relates, as
+	 * specified when the vm-object was created */
+	equeue_key_t req_vmo;
+	/* page request type. one of PAGE_REQUEST_* */
+	unsigned short req_type;
+	/* of the offset into the vm-object for which pages are being requested
+	 */
+	off_t req_offset;
+	/* the length in bytes of the region being requested */
+	size_t req_length;
+} equeue_packet_page_request_t;
+
+typedef struct {
+	/* the type of packet. one of EQUEUE_PKT_* */
+	equeue_packet_type_t p_type;
+	/* the key of the object that is responsible for the event, as specified
+	 * when the event was first subscribed to */
+	equeue_key_t p_key;
+
+	union {
+		/* p_type = EQUEUE_PKT_PAGE_REQUEST */
+		equeue_packet_page_request_t page_request;
+		/* p_type = EQUEUE_PKT_ASYNC_SIGNAL */
+		equeue_packet_async_signal_t async_signal;
+	};
+} equeue_packet_t;
+
 #endif