From: Simon Glass sjg@chromium.org
This is a draft implementation of event notification mechanism from Simon. Under this scheme, any U-Boot subsystem can register some kind of callback function to a particular event (more event types will be added later) and that function will be invoked once the event is fired.
As a first user, UEFI subsystem makes use of PROBE and REMOVE events so that we will be able to automatically create/remove efi_disk objects relying on associated block devices (UCLASS_BLK).
To run the test: ./u-boot -T -c "ut common test_event_probe"
Signed-off-by: Simon Glass sjg@chromium.org [add REMOVE event; fix checkpatch warnings] Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- common/Kconfig | 11 ++++ common/Makefile | 2 + common/board_f.c | 2 + common/event.c | 103 +++++++++++++++++++++++++++++ common/log.c | 1 + drivers/core/device-remove.c | 9 +++ drivers/core/device.c | 9 +++ include/asm-generic/global_data.h | 3 + include/dm/device-internal.h | 10 +++ include/event.h | 105 ++++++++++++++++++++++++++++++ include/event_internal.h | 34 ++++++++++ include/log.h | 2 + test/common/Makefile | 1 + test/common/event.c | 87 +++++++++++++++++++++++++ test/test-main.c | 5 ++ 15 files changed, 384 insertions(+) create mode 100644 common/event.c create mode 100644 include/event.h create mode 100644 include/event_internal.h create mode 100644 test/common/event.c
diff --git a/common/Kconfig b/common/Kconfig index 82cd864baf93..d411e5bf7a50 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -492,6 +492,17 @@ config DISPLAY_BOARDINFO_LATE
menu "Start-up hooks"
+config EVENT + bool "General-purpose event-handling mechanism" + default y if SANDBOX + help + This enables sending and processing of events, to allow interested + parties to be alerted when something happens. This is an attempt to + step the flow of weak functions, hooks, functions in board_f.c + and board_r.c and the Kconfig options below. + + See doc/develop/event.rst for more information. + config ARCH_EARLY_INIT_R bool "Call arch-specific init soon after relocation" help diff --git a/common/Makefile b/common/Makefile index 3eff71960160..4e9f59cc07ad 100644 --- a/common/Makefile +++ b/common/Makefile @@ -89,6 +89,8 @@ obj-y += malloc_simple.o endif endif
+obj-$(CONFIG_EVENT) += event.o + obj-$(CONFIG_$(SPL_TPL_)HASH) += hash.o obj-$(CONFIG_IO_TRACE) += iotrace.o obj-y += memsize.o diff --git a/common/board_f.c b/common/board_f.c index a68760092ac1..e36bdbc988fa 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -19,6 +19,7 @@ #include <dm.h> #include <env.h> #include <env_internal.h> +#include <event.h> #include <fdtdec.h> #include <fs.h> #include <hang.h> @@ -828,6 +829,7 @@ static const init_fnc_t init_sequence_f[] = { initf_malloc, log_init, initf_bootstage, /* uses its own timer, so does not need DM */ + event_init, #ifdef CONFIG_BLOBLIST bloblist_init, #endif diff --git a/common/event.c b/common/event.c new file mode 100644 index 000000000000..428628da44d6 --- /dev/null +++ b/common/event.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Events provide a general-purpose way to react to / subscribe to changes + * within U-Boot + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#define LOG_CATEGORY LOGC_EVENT + +#include <common.h> +#include <event.h> +#include <event_internal.h> +#include <log.h> +#include <malloc.h> +#include <asm/global_data.h> +#include <linux/list.h> + +DECLARE_GLOBAL_DATA_PTR; + +static void spy_free(struct event_spy *spy) +{ + list_del(&spy->sibling_node); +} + +int event_register(const char *id, enum event_t type, event_handler_t func, void *ctx) +{ + struct event_state *state = gd->event_state; + struct event_spy *spy; + + spy = malloc(sizeof(*spy)); + if (!spy) + return log_msg_ret("alloc", -ENOMEM); + + spy->id = id; + spy->type = type; + spy->func = func; + spy->ctx = ctx; + list_add_tail(&spy->sibling_node, &state->spy_head); + + return 0; +} + +int event_notify(enum event_t type, void *data, int size) +{ + struct event_state *state = gd->event_state; + struct event_spy *spy, *next; + struct event event; + + event.type = type; + if (size > sizeof(event.data)) + return log_msg_ret("size", -E2BIG); + memcpy(&event.data, data, size); + list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) { + if (spy->type == type) { + int ret; + + log_debug("Sending event %x to spy '%s'\n", type, + spy->id); + ret = spy->func(spy->ctx, &event); + + /* + * TODO: Handle various return codes to + * + * - claim an event (no others will see it) + * - return an error from the event + */ + if (ret) + return log_msg_ret("spy", ret); + } + } + + return 0; +} + +int event_uninit(void) +{ + struct event_state *state = gd->event_state; + struct event_spy *spy, *next; + + if (!state) + return 0; + list_for_each_entry_safe(spy, next, &state->spy_head, sibling_node) + spy_free(spy); + + return 0; +} + +int event_init(void) +{ + struct event_state *state; + + state = malloc(sizeof(struct event_state)); + if (!state) + return log_msg_ret("alloc", -ENOMEM); + + INIT_LIST_HEAD(&state->spy_head); + + gd->event_state = state; + + return 0; +} diff --git a/common/log.c b/common/log.c index f7e0c0fbf556..7254aa70bfdf 100644 --- a/common/log.c +++ b/common/log.c @@ -28,6 +28,7 @@ static const char *const log_cat_name[] = { "devres", "acpi", "boot", + "event", };
_Static_assert(ARRAY_SIZE(log_cat_name) == LOGC_COUNT - LOGC_NONE, diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index e6ec6ff42121..c3f8ed3e5721 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -12,6 +12,7 @@
#include <common.h> #include <errno.h> +#include <event.h> #include <log.h> #include <malloc.h> #include <dm/device.h> @@ -207,6 +208,10 @@ int device_remove(struct udevice *dev, uint flags) if (!(dev_get_flags(dev) & DM_FLAG_ACTIVATED)) return 0;
+ ret = device_notify(dev, EVT_DM_PRE_REMOVE); + if (ret) + return ret; + /* * If the child returns EKEYREJECTED, continue. It just means that it * didn't match the flags. @@ -256,6 +261,10 @@ int device_remove(struct udevice *dev, uint flags)
dev_bic_flags(dev, DM_FLAG_ACTIVATED);
+ ret = device_notify(dev, EVT_DM_POST_REMOVE); + if (ret) + goto err_remove; + return 0;
err_remove: diff --git a/drivers/core/device.c b/drivers/core/device.c index 901c1e2f7db3..6f69b234a182 100644 --- a/drivers/core/device.c +++ b/drivers/core/device.c @@ -10,6 +10,7 @@
#include <common.h> #include <cpu_func.h> +#include <event.h> #include <log.h> #include <asm/global_data.h> #include <asm/io.h> @@ -493,6 +494,10 @@ int device_probe(struct udevice *dev) if (dev_get_flags(dev) & DM_FLAG_ACTIVATED) return 0;
+ ret = device_notify(dev, EVT_DM_PRE_PROBE); + if (ret) + return ret; + drv = dev->driver; assert(drv);
@@ -597,6 +602,10 @@ int device_probe(struct udevice *dev) dev->name, ret, errno_str(ret)); }
+ ret = device_notify(dev, EVT_DM_POST_PROBE); + if (ret) + goto fail; + return 0; fail_uclass: if (device_remove(dev, DM_REMOVE_NORMAL)) { diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index c2f8fad1cb92..9f4598f09ee5 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -467,6 +467,9 @@ struct global_data { */ char *smbios_version; #endif +#if CONFIG_IS_ENABLED(EVENT) + struct event_state *event_state; +#endif }; #ifndef DO_DEPS_ONLY static_assert(sizeof(struct global_data) == GD_SIZE); diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h index 02002acb787c..63074e1de509 100644 --- a/include/dm/device-internal.h +++ b/include/dm/device-internal.h @@ -10,6 +10,7 @@ #ifndef _DM_DEVICE_INTERNAL_H #define _DM_DEVICE_INTERNAL_H
+#include <event.h> #include <linker_lists.h> #include <dm/ofnode.h>
@@ -426,4 +427,13 @@ static inline void devres_release_all(struct udevice *dev) }
#endif /* ! CONFIG_DEVRES */ + +static inline int device_notify(const struct udevice *dev, enum event_t type) +{ +#ifdef CONFIG_EVENT + return event_notify(type, &dev, sizeof(dev)); +#else + return 0; +#endif +} #endif diff --git a/include/event.h b/include/event.h new file mode 100644 index 000000000000..e2b74e6e62f0 --- /dev/null +++ b/include/event.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Events provide a general-purpose way to react to / subscribe to changes + * within U-Boot + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#ifndef __event_h +#define __event_h + +/** + * enum event_t - Types of events supported by U-Boot + * + * @EVT_DM_PRE_PROBE: Device is about to be probed + */ +enum event_t { + EVT_NONE, + EVT_TEST, + + /* Events related to driver model */ + EVT_DM_PRE_PROBE, + EVT_DM_POST_PROBE, + EVT_DM_PRE_REMOVE, + EVT_DM_POST_REMOVE, + + EVT_COUNT +}; + +union event_data { + /** + * struct event_data_test - test data + * + * @signal: A value to update the state with + */ + struct event_data_test { + int signal; + } test; + + /** + * struct event_dm - driver model event + * + * @dev: Device this event relates to + */ + struct event_dm { + struct udevice *dev; + } dm; +}; + +/** + * struct event - an event that can be sent and received + * + * @type: Event type + * @data: Data for this particular event + */ +struct event { + enum event_t type; + union event_data data; +}; + +/** Function type for event handlers */ +typedef int (*event_handler_t)(void *ctx, struct event *event); + +/** + * event_register - register a new spy + * + * @id: Spy ID + * @type: Event type to subscribe to + * @func: Function to call when the event is sent + * @ctx: Context to pass to the function + * @return 0 if OK, -ve on erropr + */ +int event_register(const char *id, enum event_t type, event_handler_t func, + void *ctx); + +/** + * event_notify() - notify spies about an event + * + * It is possible to pass in union event_data here but that may not be + * convenient if the data is elsewhere, or is one of the members of the union. + * So this uses a void * for @data, with a separate @size. + * + * @type: Event type + * @data: Event data to be sent (e.g. union_event_data) + * @size: Size of data in bytes + */ +int event_notify(enum event_t type, void *data, int size); + +#if CONFIG_IS_ENABLED(EVENT) +int event_uninit(void); +int event_init(void); +#else +static inline int event_uninit(void) +{ + return 0; +} + +static inline int event_init(void) +{ + return 0; +} +#endif + +#endif diff --git a/include/event_internal.h b/include/event_internal.h new file mode 100644 index 000000000000..19308453f7b2 --- /dev/null +++ b/include/event_internal.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Internal definitions for events + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#ifndef __event_internal_h +#define __event_internal_h + +#include <linux/list.h> + +/** + * struct event_spy - a spy that watches for an event of a particular type + * + * @id: Spy ID + * @type: Event type to subscribe to + * @func: Function to call when the event is sent + * @ctx: Context to pass to the function + */ +struct event_spy { + struct list_head sibling_node; + const char *id; + enum event_t type; + event_handler_t func; + void *ctx; +}; + +struct event_state { + struct list_head spy_head; +}; + +#endif diff --git a/include/log.h b/include/log.h index ce48d51446f5..8f35c10abb5e 100644 --- a/include/log.h +++ b/include/log.h @@ -98,6 +98,8 @@ enum log_category_t { LOGC_ACPI, /** @LOGC_BOOT: Related to boot process / boot image processing */ LOGC_BOOT, + /** @LOGC_EVENT: Related to event and event handling */ + LOGC_EVENT, /** @LOGC_COUNT: Number of log categories */ LOGC_COUNT, /** @LOGC_END: Sentinel value for lists of log categories */ diff --git a/test/common/Makefile b/test/common/Makefile index 24c9145dccc8..9087788ba6a8 100644 --- a/test/common/Makefile +++ b/test/common/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0+ obj-y += cmd_ut_common.o obj-$(CONFIG_AUTOBOOT) += test_autoboot.o +obj-$(CONFIG_EVENT) += event.o diff --git a/test/common/event.c b/test/common/event.c new file mode 100644 index 000000000000..ddce7400f269 --- /dev/null +++ b/test/common/event.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Unit tests for event handling + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#include <common.h> +#include <dm.h> +#include <event.h> +#include <test/common.h> +#include <test/test.h> +#include <test/ut.h> + +struct test_state { + struct udevice *dev; + int val; +}; + +static int h_adder(void *ctx, struct event *event) +{ + struct event_data_test *data = &event->data.test; + struct test_state *test_state = ctx; + + test_state->val += data->signal; + + return 0; +} + +static int test_event_base(struct unit_test_state *uts) +{ + struct test_state state; + int signal; + + state.val = 12; + ut_assertok(event_register("wibble", EVT_TEST, h_adder, &state)); + + signal = 17; + + /* Check that the handler is called */ + ut_assertok(event_notify(EVT_TEST, &signal, sizeof(signal))); + ut_asserteq(12 + 17, state.val); + + return 0; +} + +COMMON_TEST(test_event_base, 0); + +static int h_probe(void *ctx, struct event *event) +{ + struct test_state *test_state = ctx; + + test_state->dev = event->data.dm.dev; + switch (event->type) { + case EVT_DM_PRE_PROBE: + test_state->val |= 1; + break; + case EVT_DM_POST_PROBE: + test_state->val |= 2; + break; + default: + break; + } + + return 0; +} + +static int test_event_probe(struct unit_test_state *uts) +{ + struct test_state state; + struct udevice *dev; + + state.val = 0; + ut_assertok(event_register("pre", EVT_DM_PRE_PROBE, h_probe, &state)); + ut_assertok(event_register("post", EVT_DM_POST_PROBE, h_probe, &state)); + + /* Probe a device */ + ut_assertok(uclass_first_device_err(UCLASS_TEST_FDT, &dev)); + + /* Check that the handler is called */ + ut_asserteq(3, state.val); + + return 0; +} + +COMMON_TEST(test_event_probe, UT_TESTF_DM | UT_TESTF_SCAN_FDT); diff --git a/test/test-main.c b/test/test-main.c index 8fcb02ecea5c..fd89ff558a0e 100644 --- a/test/test-main.c +++ b/test/test-main.c @@ -7,6 +7,7 @@ #include <common.h> #include <console.h> #include <dm.h> +#include <event.h> #include <dm/root.h> #include <dm/test.h> #include <dm/uclass-internal.h> @@ -218,6 +219,9 @@ static int dm_test_restore(struct device_node *of_root) */ static int test_pre_run(struct unit_test_state *uts, struct unit_test *test) { + gd->event_state = NULL; + ut_assertok(event_init()); + if (test->flags & UT_TESTF_DM) ut_assertok(dm_test_pre_run(uts));
@@ -260,6 +264,7 @@ static int test_post_run(struct unit_test_state *uts, struct unit_test *test) ut_unsilence_console(uts); if (test->flags & UT_TESTF_DM) ut_assertok(dm_test_post_run(uts)); + ut_assertok(event_uninit());
return 0; }