tools/libs/evtchn: decouple more from mini-os

Mini-OS and libevtchn are using implementation details of each other.
Change that by letting libevtchn use the new alloc_file_type() and
get_file_from_fd() function and the generic dev pointer of struct file
from Mini-OS.

By using private struct declarations Mini-OS will be able to drop the
libevtchn specific definitions of struct evtchn_port_info and
evtchn_port_list in future. While at it use bool for "pending" and
"bound".

Switch to use xce as function parameter instead of fd where possible.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

tools/libs/evtchn/minios.c

@@ -38,29 +38,40 @@
 
 #include "private.h"
 
-extern void minios_evtchn_close_fd(int fd);
+LIST_HEAD(port_list, port_info);
+
+struct port_info {
+    LIST_ENTRY(port_info) list;
+    evtchn_port_t port;
+    bool pending;
+    bool bound;
+};
 
 extern struct wait_queue_head event_queue;
 
-/* XXX Note: This is not threadsafe */
-static struct evtchn_port_info *port_alloc(int fd)
-{
-    struct evtchn_port_info *port_info;
+void minios_evtchn_close_fd(int fd);
 
-    port_info = malloc(sizeof(struct evtchn_port_info));
+/* XXX Note: This is not threadsafe */
+static struct port_info *port_alloc(xenevtchn_handle *xce)
+{
+    struct port_info *port_info;
+    struct file *file = get_file_from_fd(xce->fd);
+    struct port_list *port_list = file->dev;
+
+    port_info = malloc(sizeof(struct port_info));
     if ( port_info == NULL )
         return NULL;
 
-    port_info->pending = 0;
+    port_info->pending = false;
     port_info->port = -1;
-    port_info->bound = 0;
+    port_info->bound = false;
 
-    LIST_INSERT_HEAD(&files[fd].evtchn.ports, port_info, list);
+    LIST_INSERT_HEAD(port_list, port_info, list);
 
     return port_info;
 }
 
-static void port_dealloc(struct evtchn_port_info *port_info)
+static void port_dealloc(struct port_info *port_info)
 {
     if ( port_info->bound )
         unbind_evtchn(port_info->port);
@@ -69,18 +80,57 @@ static void port_dealloc(struct evtchn_port_info *port_info)
     free(port_info);
 }
 
+static int evtchn_close_fd(struct file *file)
+{
+    struct port_info *port_info, *tmp;
+    struct port_list *port_list = file->dev;
+
+    LIST_FOREACH_SAFE(port_info, port_list, list, tmp)
+        port_dealloc(port_info);
+    free(port_list);
+
+    return 0;
+}
+
+static const struct file_ops evtchn_ops = {
+    .name = "evtchn",
+    .close = evtchn_close_fd,
+    .select_rd = select_read_flag,
+};
+
+static unsigned int ftype_evtchn;
+
+__attribute__((constructor))
+static void evtchn_initialize(void)
+{
+    ftype_evtchn = alloc_file_type(&evtchn_ops);
+}
+
 /*
  * XENEVTCHN_NO_CLOEXEC is being ignored, as there is no exec() call supported
  * in Mini-OS.
  */
 int osdep_evtchn_open(xenevtchn_handle *xce, unsigned int flags)
 {
-    int fd = alloc_fd(FTYPE_EVTCHN);
+    int fd;
+    struct file *file;
+    struct port_list *list;
 
-    if ( fd == -1 )
+    list = malloc(sizeof(*list));
+    if ( !list )
         return -1;
 
-    LIST_INIT(&files[fd].evtchn.ports);
+    fd = alloc_fd(ftype_evtchn);
+    file = get_file_from_fd(fd);
+
+    if ( !file )
+    {
+        free(list);
+        return -1;
+    }
+
+    file->dev = list;
+    LIST_INIT(list);
     xce->fd = fd;
     printf("evtchn_open() -> %d\n", fd);
 
@@ -104,12 +154,9 @@ int osdep_evtchn_restrict(xenevtchn_handle *xce, domid_t domid)
 
 void minios_evtchn_close_fd(int fd)
 {
-    struct evtchn_port_info *port_info, *tmp;
+    struct file *file = get_file_from_fd(fd);
 
-    LIST_FOREACH_SAFE(port_info, &files[fd].evtchn.ports, list, tmp)
-        port_dealloc(port_info);
-
-    files[fd].type = FTYPE_NONE;
+    evtchn_close_fd(file);
 }
 
 int xenevtchn_notify(xenevtchn_handle *xce, evtchn_port_t port)
@@ -129,42 +176,43 @@ int xenevtchn_notify(xenevtchn_handle *xce, evtchn_port_t port)
 
 static void evtchn_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
 {
-    int fd = (int)(intptr_t)data;
-    struct evtchn_port_info *port_info;
+    xenevtchn_handle *xce = data;
+    struct file *file = get_file_from_fd(xce->fd);
+    struct port_info *port_info;
+    struct port_list *port_list;
 
-    assert(files[fd].type == FTYPE_EVTCHN);
+    assert(file);
+    port_list = file->dev;
     mask_evtchn(port);
-    LIST_FOREACH(port_info, &files[fd].evtchn.ports, list)
+    LIST_FOREACH(port_info, port_list, list)
     {
         if ( port_info->port == port )
             goto found;
     }
 
-    printk("Unknown port for handle %d\n", fd);
+    printk("Unknown port %d for handle %d\n", port, xce->fd);
     return;
 
  found:
-    port_info->pending = 1;
-    files[fd].read = 1;
+    port_info->pending = true;
+    file->read = true;
     wake_up(&event_queue);
 }
 
 xenevtchn_port_or_error_t xenevtchn_bind_unbound_port(xenevtchn_handle *xce,
                                                       uint32_t domid)
 {
-    int fd = xce->fd;
-    struct evtchn_port_info *port_info;
+    struct port_info *port_info;
     int ret;
     evtchn_port_t port;
 
     assert(get_current() == main_thread);
-    port_info = port_alloc(fd);
+    port_info = port_alloc(xce);
     if ( port_info == NULL )
         return -1;
 
     printf("xenevtchn_bind_unbound_port(%d)", domid);
-    ret = evtchn_alloc_unbound(domid, evtchn_handler,
-                               (void *)(intptr_t)fd, &port);
+    ret = evtchn_alloc_unbound(domid, evtchn_handler, xce, &port);
     printf(" = %d\n", ret);
 
     if ( ret < 0 )
@@ -174,7 +222,7 @@ xenevtchn_port_or_error_t xenevtchn_bind_unbound_port(xenevtchn_handle *xce,
         return -1;
     }
 
-    port_info->bound = 1;
+    port_info->bound = true;
     port_info->port = port;
     unmask_evtchn(port);
 
@@ -185,19 +233,18 @@ xenevtchn_port_or_error_t xenevtchn_bind_interdomain(xenevtchn_handle *xce,
                                                      uint32_t domid,
                                                      evtchn_port_t remote_port)
 {
-    int fd = xce->fd;
-    struct evtchn_port_info *port_info;
+    struct port_info *port_info;
     evtchn_port_t local_port;
     int ret;
 
     assert(get_current() == main_thread);
-    port_info = port_alloc(fd);
+    port_info = port_alloc(xce);
     if ( port_info == NULL )
         return -1;
 
     printf("xenevtchn_bind_interdomain(%d, %"PRId32")", domid, remote_port);
     ret = evtchn_bind_interdomain(domid, remote_port, evtchn_handler,
-                                  (void *)(intptr_t)fd, &local_port);
+                                  xce, &local_port);
     printf(" = %d\n", ret);
 
     if ( ret < 0 )
@@ -207,7 +254,7 @@ xenevtchn_port_or_error_t xenevtchn_bind_interdomain(xenevtchn_handle *xce,
         return -1;
     }
 
-    port_info->bound = 1;
+    port_info->bound = true;
     port_info->port = local_port;
     unmask_evtchn(local_port);
 
@@ -217,9 +264,11 @@ xenevtchn_port_or_error_t xenevtchn_bind_interdomain(xenevtchn_handle *xce,
 int xenevtchn_unbind(xenevtchn_handle *xce, evtchn_port_t port)
 {
     int fd = xce->fd;
-    struct evtchn_port_info *port_info;
+    struct file *file = get_file_from_fd(fd);
+    struct port_info *port_info;
+    struct port_list *port_list = file->dev;
 
-    LIST_FOREACH(port_info, &files[fd].evtchn.ports, list)
+    LIST_FOREACH(port_info, port_list, list)
     {
         if ( port_info->port == port )
         {
@@ -238,17 +287,16 @@ int xenevtchn_unbind(xenevtchn_handle *xce, evtchn_port_t port)
 xenevtchn_port_or_error_t xenevtchn_bind_virq(xenevtchn_handle *xce,
                                               unsigned int virq)
 {
-    int fd = xce->fd;
-    struct evtchn_port_info *port_info;
+    struct port_info *port_info;
     evtchn_port_t port;
 
     assert(get_current() == main_thread);
-    port_info = port_alloc(fd);
+    port_info = port_alloc(xce);
     if ( port_info == NULL )
         return -1;
 
     printf("xenevtchn_bind_virq(%d)", virq);
-    port = bind_virq(virq, evtchn_handler, (void *)(intptr_t)fd);
+    port = bind_virq(virq, evtchn_handler, xce);
     printf(" = %d\n", port);
 
     if ( port < 0 )
@@ -258,7 +306,7 @@ xenevtchn_port_or_error_t xenevtchn_bind_virq(xenevtchn_handle *xce,
         return -1;
     }
 
-    port_info->bound = 1;
+    port_info->bound = true;
     port_info->port = port;
     unmask_evtchn(port);
 
@@ -267,27 +315,28 @@ xenevtchn_port_or_error_t xenevtchn_bind_virq(xenevtchn_handle *xce,
 
 xenevtchn_port_or_error_t xenevtchn_pending(xenevtchn_handle *xce)
 {
-    int fd = xce->fd;
-    struct evtchn_port_info *port_info;
+    struct file *file = get_file_from_fd(xce->fd);
+    struct port_info *port_info;
+    struct port_list *port_list = file->dev;
     unsigned long flags;
     evtchn_port_t ret = -1;
 
     local_irq_save(flags);
 
-    files[fd].read = 0;
+    file->read = false;
 
-    LIST_FOREACH(port_info, &files[fd].evtchn.ports, list)
+    LIST_FOREACH(port_info, port_list, list)
     {
         if ( port_info->port != -1 && port_info->pending )
         {
             if ( ret == -1 )
             {
                 ret = port_info->port;
-                port_info->pending = 0;
+                port_info->pending = false;
             }
             else
             {
-                files[fd].read = 1;
+                file->read = true;
                 break;
             }
         }