[PATCH 08/19] dm: add event notification
Heinrich Schuchardt
xypron.glpk at gmx.de
Sat Feb 5 09:59:27 CET 2022
On 2/2/22 02:08, AKASHI Takahiro wrote:
> From: Simon Glass <sjg at 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 at chromium.org>
> [add REMOVE event; fix checkpatch warnings]
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at 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 at 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;
This breaks 'make htmldocs'.
./include/asm-generic/global_data.h:474: warning: Function parameter or
member 'event_state' not described in 'global_data'
Best regards
Heinrich
> +#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 at 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 at 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 at 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;
> }
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