This is simple test and playground useful kstate subsystem development.
It contains some structure with different kind of data which migrated
across kexec to the new kernel using kstate.
Signed-off-by: Andrey Ryabinin <arbn@xxxxxxxxxxxxxxx>
---
include/linux/kstate.h | 1 +
lib/Makefile | 2 +
lib/test_kstate.c | 89 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 92 insertions(+)
create mode 100644 lib/test_kstate.c
diff --git a/include/linux/kstate.h b/include/linux/kstate.h
index 855acb339d5d7..2ddbe41a1f171 100644
--- a/include/linux/kstate.h
+++ b/include/linux/kstate.h
@@ -31,6 +31,7 @@ struct kstate_field {
enum kstate_ids {
KSTATE_PAGE_ID,
KSTATE_RSVD_MEM_ID,
+ KSTATE_TEST_ID,
KSTATE_LAST_ID = -1,
};
diff --git a/lib/Makefile b/lib/Makefile
index 773adf88af416..2432e47664c35 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -354,6 +354,8 @@ obj-$(CONFIG_PARMAN) += parman.o
obj-y += group_cpus.o
+obj-$(CONFIG_KSTATE) += test_kstate.o
+
# GCC library routines
obj-$(CONFIG_GENERIC_LIB_ASHLDI3) += ashldi3.o
obj-$(CONFIG_GENERIC_LIB_ASHRDI3) += ashrdi3.o
diff --git a/lib/test_kstate.c b/lib/test_kstate.c
new file mode 100644
index 0000000000000..e95e3110f8949
--- /dev/null
+++ b/lib/test_kstate.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/io.h>
+#include <linux/kstate.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+unsigned long ulong_val;
+struct kstate_test_data {
+ int i;
+ unsigned long *p_ulong;
+ char s[10];
+ struct page *page;
+};
+
+struct kstate_description test_state = {
+ .name = "test",
+ .version_id = 1,
+ .id = KSTATE_TEST_ID,
+ .state_list = LIST_HEAD_INIT(test_state.state_list),
+ .fields = (const struct kstate_field[]) {
+ KSTATE_SIMPLE(i, struct kstate_test_data),
+ KSTATE_SIMPLE(s, struct kstate_test_data),
+ KSTATE_POINTER(p_ulong, struct kstate_test_data),
+ {
+ .name = "page",
+ .flags = KS_CUSTOM,
+ .offset = offsetof(struct kstate_test_data, page),
+ .save = kstate_page_save,
+ },
+ KSTATE_SIMPLE(page, struct kstate_test_data),
+ KSTATE_END_OF_LIST()
+ },
+};
+
+static struct kstate_test_data test_data;
+
+static int init_test_data(void)
+{
+ struct page *page;
+ int i;
+
+ test_data.i = 10;
+ ulong_val = 20;
+ memcpy(test_data.s, "abcdefghk", sizeof(test_data.s));
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ for (i = 0; i < PAGE_SIZE/4; i += 4)
+ *((u32 *)page_address(page) + i) = 0xdeadbeef;
+ test_data.page = page;
+ return 0;
+}
+
+static void validate_test_data(void)
+{
+ int i;
+
+ WARN_ON(test_data.i != 10);
+ WARN_ON(*test_data.p_ulong != 20);
+ WARN_ON(strcmp(test_data.s, "abcdefghk") != 0);
+
+ for (i = 0; i < PAGE_SIZE/4; i += 4) {
+ u32 val = *((u32 *)page_address(test_data.page) + i);
+
+ WARN_ON(val != 0xdeadbeef);
+ }
+}
+
+static int __init test_kstate_init(void)
+{
+ int ret = 0;
+
+ test_data.p_ulong = &ulong_val;
+
+ if (!is_migrate_kernel()) {
+ ret = init_test_data();
+ if (ret)
+ goto out;
+ }
+
+ kstate_register(&test_state, &test_data);
+
+ validate_test_data();
+
+out:
+ return ret;
+}
+__initcall(test_kstate_init);
--
2.45.2
