WIP(oom): driver skeleton
Change-Id: Ia8d6c34fa2939de52a2bff0aed514b2b02c0c344
diff --git a/system/dev/misc/oom/oom-dev.c b/system/dev/misc/oom/oom-dev.c
new file mode 100644
index 0000000..ff64aa5
--- /dev/null
+++ b/system/dev/misc/oom/oom-dev.c
@@ -0,0 +1,114 @@
+// Copyright 2017 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <ddk/binding.h>
+#include <ddk/device.h>
+#include <ddk/driver.h>
+
+#include <zircon/syscalls.h>
+#include <zircon/threads.h>
+#include <zircon/types.h>
+
+// ioctls: #include <zircon/device/oom.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <threads.h>
+
+static zx_status_t oom_ioctl(void* ctx, uint32_t op,
+ const void* cmd, size_t cmdlen,
+ void* reply, size_t max, size_t* out_actual) {
+ switch (op) {
+ // case IOCTL_OOM_START: {
+ // if (cmdlen != sizeof(uint32_t)) {
+ // return ZX_ERR_INVALID_ARGS;
+ // }
+ // uint32_t group_mask = *(uint32_t *)cmd;
+ // return zx_oom_control(get_root_resource(), OOM_ACTION_START, group_mask, NULL);
+ // }
+ // case IOCTL_OOM_STOP: {
+ // zx_oom_control(get_root_resource(), OOM_ACTION_STOP, 0, NULL);
+ // zx_oom_control(get_root_resource(), OOM_ACTION_REWIND, 0, NULL);
+ // return ZX_OK;
+ // }
+ // TODO: get a port that's notified on lowmem events, at certain thresholds,
+ // requests for cache clearing, ...
+ default:
+ return ZX_ERR_INVALID_ARGS;
+ }
+}
+
+static /*const*/ zx_protocol_device_t oom_device_proto = {
+ .version = DEVICE_OPS_VERSION,
+ .ioctl = oom_ioctl,
+};
+
+static int ranker_thread(void *arg) {
+ while (true) {
+ zx_nanosleep(zx_deadline_after(ZX_SEC(1)));
+ }
+ return 0;
+}
+
+// Type of the |cookie| args to zx_driver_ops_t functions.
+typedef struct {
+ zx_device_t* dev;
+ thrd_t ranker_thread;
+} oom_cookie_t;
+
+static zx_status_t oom_bind(void* unused_ctx, zx_device_t* parent,
+ void** out_cookie) {
+ // Add the device.
+ /*const*/ device_add_args_t args = {
+ .version = DEVICE_ADD_ARGS_VERSION,
+ .name = "oom",
+ // TODO(dbort): Use .ctx to hold a channel to the ranker thread, and
+ // maybe dispatchers that will notify observers.
+ .ops = &oom_device_proto,
+ };
+ zx_device_t* dev;
+ zx_status_t s = device_add(parent, &args, &dev);
+ if (s != ZX_OK) {
+ return s;
+ }
+
+ // Allocate the cookie.
+ oom_cookie_t *cookie = (oom_cookie_t*)calloc(1, sizeof(oom_cookie_t));
+ if (cookie == NULL) {
+ device_remove(dev);
+ return ZX_ERR_NO_MEMORY;
+ }
+ cookie->dev = dev;
+
+ // Start the thread.
+ int ts = thrd_create_with_name(
+ &cookie->ranker_thread, ranker_thread, NULL, "ranker");
+ if (ts != thrd_success) {
+ device_remove(dev);
+ free(cookie);
+ return thrd_status_to_zx_status(ts);
+ }
+
+ *out_cookie = cookie;
+ return ZX_OK;
+}
+
+void oom_unbind(void* unused_ctx, zx_device_t* parent, void* cookie) {
+ //xxx kill, join the thread. Ask it to die nicely
+ // thrd_join(cookie->ranker_thread, NULL);
+ memset(cookie, 0, sizeof(oom_cookie_t));
+ free(cookie);
+}
+
+static /*const*/ zx_driver_ops_t oom_driver_ops = {
+ .version = DRIVER_OPS_VERSION,
+ .bind = oom_bind,
+ .unbind = oom_unbind,
+};
+
+ZIRCON_DRIVER_BEGIN(oom, oom_driver_ops, "zircon", "0.1", 1)
+BI_MATCH_IF(EQ, BIND_PROTOCOL, ZX_PROTOCOL_MISC_PARENT)
+,
+ ZIRCON_DRIVER_END(oom)
diff --git a/system/dev/misc/oom/rules.mk b/system/dev/misc/oom/rules.mk
new file mode 100644
index 0000000..bccb529
--- /dev/null
+++ b/system/dev/misc/oom/rules.mk
@@ -0,0 +1,17 @@
+# Copyright 2017 The Fuchsia Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+MODULE := $(LOCAL_DIR)
+
+MODULE_TYPE := driver
+
+MODULE_SRCS := $(LOCAL_DIR)/oom-dev.c
+
+MODULE_STATIC_LIBS := system/ulib/ddk
+
+MODULE_LIBS := system/ulib/driver system/ulib/zircon system/ulib/c
+
+include make/module.mk
