Use bus interface in the serial device

Makefile

@@ -14,6 +14,7 @@ all: $(BIN)
 OBJS := \
 	vm.o \
 	serial.o \
+	bus.o \
 	pci.o \
 	virtio-pci.o \
 	virtq.o \

src/bus.c

@@ -0,0 +1,66 @@
+#include "bus.h"
+#include <stddef.h>
+
+static inline struct dev *bus_find_dev(struct bus *bus, uint64_t addr)
+{
+    struct dev **p = &bus->head;
+
+    for (; *p; p = &(*p)->next) {
+        uint64_t start = (*p)->base;
+        uint64_t end = start + (*p)->len - 1;
+        if (addr >= start && addr <= end)
+            return *p;
+    }
+    return NULL;
+}
+
+void bus_handle_io(struct bus *bus,
+                   void *data,
+                   uint8_t is_write,
+                   uint64_t addr,
+                   uint8_t size)
+{
+    struct dev *dev = bus_find_dev(bus, addr);
+
+    if (dev && addr + size - 1 <= dev->base + dev->len - 1) {
+        dev->do_io(dev->owner, data, is_write, addr - dev->base, size);
+    }
+}
+
+void bus_register_dev(struct bus *bus, struct dev *dev)
+{
+    dev->next = bus->head;
+    bus->head = dev;
+    bus->dev_num++;
+}
+
+void bus_deregister_dev(struct bus *bus, struct dev *dev)
+{
+    struct dev **p = &bus->head;
+
+    while (*p != dev && *p) {
+        p = &(*p)->next;
+    }
+
+    if (*p)
+        *p = (*p)->next;
+}
+
+void bus_init(struct bus *bus)
+{
+    bus->dev_num = 0;
+    bus->head = NULL;
+}
+
+void dev_init(struct dev *dev,
+              uint64_t base,
+              uint64_t len,
+              void *owner,
+              dev_io_fn do_io)
+{
+    dev->base = base;
+    dev->len = len;
+    dev->owner = owner;
+    dev->do_io = do_io;
+    dev->next = NULL;
+}

src/bus.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <stdint.h>
+
+struct dev;
+
+typedef void (*dev_io_fn)(void *owner,
+                          void *data,
+                          uint8_t is_write,
+                          uint64_t offset,
+                          uint8_t size);
+
+struct dev {
+    uint64_t base;
+    uint64_t len;
+    void *owner;
+    dev_io_fn do_io;
+    struct dev *next;
+};
+
+struct bus {
+    uint64_t dev_num;
+    struct dev *head;
+};
+
+void bus_register_dev(struct bus *bus, struct dev *dev);
+void bus_deregister_dev(struct bus *bus, struct dev *dev);
+void bus_handle_io(struct bus *bus,
+                   void *data,
+                   uint8_t is_write,
+                   uint64_t addr,
+                   uint8_t size);
+void bus_init(struct bus *bus);
+void dev_init(struct dev *dev,
+              uint64_t base,
+              uint64_t len,
+              void *owner,
+              dev_io_fn do_io);

src/pci.c

@@ -4,70 +4,6 @@
 #include "pci.h"
 #include "utils.h"
 
-static inline struct dev *bus_find_dev(struct bus *bus, uint64_t addr)
-{
-    struct dev **p = &bus->head;
-
-    for (; *p; p = &(*p)->next) {
-        uint64_t start = (*p)->base;
-        uint64_t end = start + (*p)->len - 1;
-        if (addr >= start && addr <= end)
-            return *p;
-    }
-    return NULL;
-}
-
-void bus_handle_io(struct bus *bus,
-                   void *data,
-                   uint8_t is_write,
-                   uint64_t addr,
-                   uint8_t size)
-{
-    struct dev *dev = bus_find_dev(bus, addr);
-
-    if (dev && addr + size - 1 <= dev->base + dev->len - 1) {
-        dev->do_io(dev->owner, data, is_write, addr - dev->base, size);
-    }
-}
-
-void bus_register_dev(struct bus *bus, struct dev *dev)
-{
-    dev->next = bus->head;
-    bus->head = dev;
-    bus->dev_num++;
-}
-
-void bus_deregister_dev(struct bus *bus, struct dev *dev)
-{
-    struct dev **p = &bus->head;
-
-    while (*p != dev && *p) {
-        p = &(*p)->next;
-    }
-
-    if (*p)
-        *p = (*p)->next;
-}
-
-void bus_init(struct bus *bus)
-{
-    bus->dev_num = 0;
-    bus->head = NULL;
-}
-
-static inline void dev_init(struct dev *dev,
-                            uint64_t base,
-                            uint64_t len,
-                            void *owner,
-                            dev_io_fn do_io)
-{
-    dev->base = base;
-    dev->len = len;
-    dev->owner = owner;
-    dev->do_io = do_io;
-    dev->next = NULL;
-}
-
 static void pci_address_io(void *owner,
                            void *data,
                            uint8_t is_write,

src/pci.h

@@ -4,36 +4,7 @@
 #include <linux/pci_regs.h>
 #include <stdbool.h>
 #include <stdint.h>
-
-struct dev;
-
-typedef void (*dev_io_fn)(void *owner,
-                          void *data,
-                          uint8_t is_write,
-                          uint64_t offset,
-                          uint8_t size);
-
-struct dev {
-    uint64_t base;
-    uint64_t len;
-    void *owner;
-    dev_io_fn do_io;
-    struct dev *next;
-};
-
-struct bus {
-    uint64_t dev_num;
-    struct dev *head;
-};
-
-void bus_register_dev(struct bus *bus, struct dev *dev);
-void bus_deregister_dev(struct bus *bus, struct dev *dev);
-void bus_handle_io(struct bus *bus,
-                   void *data,
-                   uint8_t is_write,
-                   uint64_t addr,
-                   uint8_t size);
-void bus_init(struct bus *bus);
+#include "bus.h"
 
 union pci_config_address {
     struct {
@@ -84,4 +55,4 @@ void pci_dev_init(struct pci_dev *dev,
                   struct pci *pci,
                   struct bus *io_bus,
                   struct bus *mmio_bus);
-void pci_init();
+void pci_init();

src/serial.c

@@ -196,9 +196,23 @@ static void serial_out(serial_dev_t *s, uint16_t offset, void *data)
     }
 }
 
+
+static void serial_handle_io(void *owner,
+                             void *data,
+                             uint8_t is_write,
+                             uint64_t offset,
+                             uint8_t size)
+{
+    serial_dev_t *s = (serial_dev_t *) owner;
+    void (*serial_op)(serial_dev_t *, uint16_t, void *) =
+        is_write ? serial_out : serial_in;
+
+    serial_op(s, offset, data);
+}
+
 static void handler(int sig, siginfo_t *si, void *uc) {}
 
-int serial_init(serial_dev_t *s)
+int serial_init(serial_dev_t *s, struct bus *bus)
 {
     sigset_t mask;
 
@@ -226,18 +240,10 @@ int serial_init(serial_dev_t *s)
     if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1)
         return throw_err("Failed to unblock timer signal");
 
-    return 0;
-}
-
-void serial_handle(serial_dev_t *s, struct kvm_run *r)
-{
-    void *data = (uint8_t *) r + r->io.data_offset;
-    void (*serial_op)(serial_dev_t *, uint16_t, void *) =
-        (r->io.direction == KVM_EXIT_IO_OUT) ? serial_out : serial_in;
+    dev_init(&s->dev, COM1_PORT_BASE, COM1_PORT_SIZE, s, serial_handle_io);
+    bus_register_dev(bus, &s->dev);
 
-    uint32_t c = r->io.count;
-    for (uint16_t off = r->io.port - COM1_PORT_BASE; c--; data += r->io.size)
-        serial_op(s, off, data);
+    return 0;
 }
 
 void serial_exit(serial_dev_t *s)

src/serial.h

@@ -2,20 +2,20 @@
 
 #include <linux/kvm.h>
 #include <pthread.h>
+#include "bus.h"
 
 #define COM1_PORT_BASE 0x03f8
 #define COM1_PORT_SIZE 8
-#define COM1_PORT_END (COM1_PORT_BASE + COM1_PORT_SIZE)
 
 typedef struct serial_dev serial_dev_t;
 
 struct serial_dev {
     void *priv;
     pthread_t main_tid, worker_tid;
     int infd; /* file descriptor for serial input */
+    struct dev dev;
 };
 
 void serial_console(serial_dev_t *s);
-int serial_init(serial_dev_t *s);
-void serial_handle(serial_dev_t *s, struct kvm_run *r);
+int serial_init(serial_dev_t *s, struct bus *bus);
 void serial_exit(serial_dev_t *s);

src/vm.c

@@ -115,11 +115,11 @@ int vm_init(vm_t *v)
 
     vm_init_regs(v);
     vm_init_cpu_id(v);
-    if (serial_init(&v->serial))
-        return throw_err("Failed to init UART device");
     bus_init(&v->io_bus);
     bus_init(&v->mmio_bus);
     pci_init(&v->pci, &v->io_bus);
+    if (serial_init(&v->serial, &v->io_bus))
+        return throw_err("Failed to init UART device");
     virtio_blk_init(&v->virtio_blk_dev);
     return 0;
 }
@@ -223,13 +223,9 @@ void vm_handle_io(vm_t *v, struct kvm_run *run)
     void *data = (void *) run + run->io.data_offset;
     bool is_write = run->io.direction == KVM_EXIT_IO_OUT;
 
-    if (run->io.port >= COM1_PORT_BASE && run->io.port < COM1_PORT_END) {
-        serial_handle(&v->serial, run);
-    } else {
-        for (int i = 0; i < run->io.count; i++) {
-            bus_handle_io(&v->io_bus, data, is_write, addr, run->io.size);
-            addr += run->io.size;
-        }
+    for (int i = 0; i < run->io.count; i++) {
+        bus_handle_io(&v->io_bus, data, is_write, addr, run->io.size);
+        addr += run->io.size;
     }
 }