[PATCH 5/5] cyclic: get rid of cyclic_init()
Rasmus Villemoes
rasmus.villemoes at prevas.dk
Fri Oct 28 13:50:54 CEST 2022
Currently, we must call cyclic_init() at some point before
cyclic_register() becomes possible. That turns out to be somewhat
awkward, especially with SPL, and has resulted in a watchdog callback
not being registered, thus causing the board to prematurely reset.
We already rely on gd->cyclic reliably being set to NULL by the asm
code that clears all of gd. Now that the cyclic list is a hlist, and
thus an empty list is represented by a NULL head pointer, and struct
cyclic_drv has no other members, we can just as well drop a level of
indirection and put the hlist_head directly in struct
global_data. This doesn't increase the size of struct global_data,
gets rid of an early malloc(), and generates slightly smaller code.
But primarily, this avoids having to call cyclic_init() early; the cyclic
infrastructure is simply ready to register callbacks as soon as we
enter C code.
We can still end up with schedule() being called from asm very early,
so we still need to check that gd itself has been properly initialized
[*], but once it has, gd->cyclic_list is perfectly fine to access, and
will just be an empty list.
As for cyclic_uninit(), it was never really the opposite of
cyclic_init() since it didn't free the struct cyclic_drv nor set
gd->cyclic to NULL. Rename it to cyclic_unregister_all() and use that
in test/, and also insert a call at the end of the board_init_f
sequence so that gd->cyclic_list is a fresh empty list before we enter
board_init_r().
A small piece of ugliness is that I had to add a cast in
cyclic_get_list() to silence a "discards 'volatile' qualifier"
warning, but that is completely equivalent to the existing handling of
the uclass_root_s list_head member.
[*] I'm not really sure where we guarantee that the register used for
gd contains 0 until it gets explicitly initialized, but that must be
the case, otherwise testing gd for being NULL would not make much sense.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
common/board_f.c | 2 +-
common/board_r.c | 1 -
common/cyclic.c | 32 +++++++------------------------
include/asm-generic/global_data.h | 4 ++--
include/cyclic.h | 27 +++-----------------------
test/test-main.c | 3 +--
6 files changed, 14 insertions(+), 55 deletions(-)
diff --git a/common/board_f.c b/common/board_f.c
index 4355d1c82d..1f9140a065 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -844,7 +844,6 @@ static const init_fnc_t init_sequence_f[] = {
initf_malloc,
log_init,
initf_bootstage, /* uses its own timer, so does not need DM */
- cyclic_init,
event_init,
#ifdef CONFIG_BLOBLIST
bloblist_init,
@@ -962,6 +961,7 @@ static const init_fnc_t init_sequence_f[] = {
do_elf_reloc_fixups,
#endif
clear_bss,
+ cyclic_unregister_all,
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX) && \
!CONFIG_IS_ENABLED(X86_64)
jump_to_copy,
diff --git a/common/board_r.c b/common/board_r.c
index 92ca2066ee..0e2e63a21b 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -614,7 +614,6 @@ static init_fnc_t init_sequence_r[] = {
#endif
initr_barrier,
initr_malloc,
- cyclic_init,
log_init,
initr_bootstage, /* Needs malloc() but has its own timer */
#if defined(CONFIG_CONSOLE_RECORD)
diff --git a/common/cyclic.c b/common/cyclic.c
index 32d9bf0d02..a49bfc88f5 100644
--- a/common/cyclic.c
+++ b/common/cyclic.c
@@ -22,7 +22,8 @@ void hw_watchdog_reset(void);
struct hlist_head *cyclic_get_list(void)
{
- return &gd->cyclic->cyclic_list;
+ /* Silence "discards 'volatile' qualifier" warning. */
+ return (struct hlist_head *)&gd->cyclic_list;
}
struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
@@ -30,11 +31,6 @@ struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
{
struct cyclic_info *cyclic;
- if (!gd->cyclic) {
- pr_debug("Cyclic IF not ready yet\n");
- return NULL;
- }
-
cyclic = calloc(1, sizeof(struct cyclic_info));
if (!cyclic) {
pr_debug("Memory allocation error\n");
@@ -47,7 +43,7 @@ struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
cyclic->name = strdup(name);
cyclic->delay_us = delay_us;
cyclic->start_time_us = timer_get_us();
- hlist_add_head(&cyclic->list, &gd->cyclic->cyclic_list);
+ hlist_add_head(&cyclic->list, cyclic_get_list());
return cyclic;
}
@@ -71,7 +67,7 @@ void cyclic_run(void)
return;
gd->flags |= GD_FLG_CYCLIC_RUNNING;
- hlist_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list) {
+ hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list) {
/*
* Check if this cyclic function needs to get called, e.g.
* do not call the cyclic func too often
@@ -113,31 +109,17 @@ void schedule(void)
* schedule() might get called very early before the cyclic IF is
* ready. Make sure to only call cyclic_run() when it's initalized.
*/
- if (gd && gd->cyclic)
+ if (gd)
cyclic_run();
}
-int cyclic_uninit(void)
+int cyclic_unregister_all(void)
{
struct cyclic_info *cyclic;
struct hlist_node *tmp;
- hlist_for_each_entry_safe(cyclic, tmp, &gd->cyclic->cyclic_list, list)
+ hlist_for_each_entry_safe(cyclic, tmp, cyclic_get_list(), list)
cyclic_unregister(cyclic);
return 0;
}
-
-int cyclic_init(void)
-{
- int size = sizeof(struct cyclic_drv);
-
- gd->cyclic = (struct cyclic_drv *)malloc(size);
- if (!gd->cyclic)
- return -ENOMEM;
-
- memset(gd->cyclic, '\0', size);
- INIT_HLIST_HEAD(&gd->cyclic->cyclic_list);
-
- return 0;
-}
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index ca36907b20..1a2e55454d 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -481,9 +481,9 @@ struct global_data {
#endif
#ifdef CONFIG_CYCLIC
/**
- * @cyclic: cyclic driver data
+ * @cyclic_list: list of registered cyclic functions
*/
- struct cyclic_drv *cyclic;
+ struct hlist_head cyclic_list;
#endif
/**
* @dmtag_list: List of DM tags
diff --git a/include/cyclic.h b/include/cyclic.h
index 4a11f9b105..44ad3cb6b8 100644
--- a/include/cyclic.h
+++ b/include/cyclic.h
@@ -14,15 +14,6 @@
#include <linux/list.h>
#include <asm/types.h>
-/**
- * struct cyclic_drv - Cyclic driver internal data
- *
- * @cyclic_list: Cylic list node
- */
-struct cyclic_drv {
- struct hlist_head cyclic_list;
-};
-
/**
* struct cyclic_info - Information about cyclic execution function
*
@@ -75,18 +66,11 @@ struct cyclic_info *cyclic_register(cyclic_func_t func, uint64_t delay_us,
int cyclic_unregister(struct cyclic_info *cyclic);
/**
- * cyclic_init() - Set up cyclic functions
- *
- * Init a list of cyclic functions, so that these can be added as needed
- */
-int cyclic_init(void);
-
-/**
- * cyclic_uninit() - Clean up cyclic functions
+ * cyclic_unregister_all() - Clean up cyclic functions
*
* This removes all cyclic functions
*/
-int cyclic_uninit(void);
+int cyclic_unregister_all(void);
/**
* cyclic_get_list() - Get cyclic list pointer
@@ -134,12 +118,7 @@ static inline void schedule(void)
{
}
-static inline int cyclic_init(void)
-{
- return 0;
-}
-
-static inline int cyclic_uninit(void)
+static inline int cyclic_unregister_all(void)
{
return 0;
}
diff --git a/test/test-main.c b/test/test-main.c
index a98a77d68f..554dd8d96b 100644
--- a/test/test-main.c
+++ b/test/test-main.c
@@ -287,7 +287,6 @@ static int dm_test_restore(struct device_node *of_root)
static int test_pre_run(struct unit_test_state *uts, struct unit_test *test)
{
ut_assertok(event_init());
- ut_assertok(cyclic_init());
if (test->flags & UT_TESTF_DM)
ut_assertok(dm_test_pre_run(uts));
@@ -347,7 +346,7 @@ 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(cyclic_uninit());
+ ut_assertok(cyclic_unregister_all());
ut_assertok(event_uninit());
free(uts->of_other);
--
2.37.2
More information about the U-Boot
mailing list