[PATCH 3/7] thermal/drivers/core: Add init section table for self-encapsulation

Daniel Lezcano
2019-04-02T16:12:46Z

Currently the governors are declared in their respective files but they
export their [un]register functions which in turn call the [un]register
the governors core's functions. That implies a cyclic dependency which is
not desirable. There is a way to self-encapsulate the governors by letting
them to declare themselves in a __init section table.

Define the table in the asm generic linker description like the other
tables and provide the specific macros to deal with.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
drivers/thermal/thermal_core.h | 16 ++++++++++++++++
include/asm-generic/vmlinux.lds.h | 11 +++++++++++
2 files changed, 27 insertions(+)

diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 0df190ed82a7..28d18083e969 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -15,6 +15,22 @@
/* Initial state of a cooling device during binding */
#define THERMAL_NO_TARGET -1UL

+/* Init section thermal table */
+extern struct thermal_governor * __governor_thermal_table[];
+extern struct thermal_governor * __governor_thermal_table_end[];
+
+#define THERMAL_TABLE_ENTRY(table, name) \
+ static typeof(name) * __thermal_table_entry_##name \
+ __used __section(__##table##_thermal_table) \
+ = &name;
+
+#define THERMAL_GOVERNOR_DECLARE(name) THERMAL_TABLE_ENTRY(governor, name)
+
+#define for_each_governor_table(__governor) \
+ for (__governor = __governor_thermal_table; \
+ __governor < __governor_thermal_table_end; \
+ __governor++)
+
/*
* This structure is used to describe the behavior of
* a certain cooling device on a certain trip point
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f8f6f04c4453..9893a3ed242a 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -239,6 +239,16 @@
#define ACPI_PROBE_TABLE(name)
#endif

+#ifdef CONFIG_THERMAL
+#define THERMAL_TABLE(name) \
+ . = ALIGN(8); \
+ __##name##_thermal_table = .; \
+ KEEP(*(__##name##_thermal_table)) \
+ __##name##_thermal_table_end = .;
+#else
+#define THERMAL_TABLE(name)
+#endif
+
#define KERNEL_DTB() \
STRUCT_ALIGN(); \
__dtb_start = .; \
@@ -609,6 +619,7 @@
IRQCHIP_OF_MATCH_TABLE() \
ACPI_PROBE_TABLE(irqchip) \
ACPI_PROBE_TABLE(timer) \
+ THERMAL_TABLE(governor) \
EARLYCON_TABLE() \
LSM_TABLE()

--
2.17.1