[PATCH v2 2/2] of: Add unit tests for applying overlays

frowand.list
2017-04-24T23:06:04Z

From: Frank Rowand <frank.rowand@sony.com>

Existing overlay unit tests examine individual pieces of the overlay
code. The new tests target the entire process of applying an overlay.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---

There are checkpatch warnings. I have reviewed them and feel they
can be ignored.

drivers/of/fdt.c | 14 +-
drivers/of/of_private.h | 11 +
drivers/of/unittest-data/Makefile | 17 +-
drivers/of/unittest-data/overlay.dts | 53 ++++
drivers/of/unittest-data/overlay_bad_phandle.dts | 20 ++
drivers/of/unittest-data/overlay_base.dts | 80 ++++++
drivers/of/unittest.c | 318 +++++++++++++++++++++++
7 files changed, 505 insertions(+), 8 deletions(-)
create mode 100644 drivers/of/unittest-data/overlay.dts
create mode 100644 drivers/of/unittest-data/overlay_bad_phandle.dts
create mode 100644 drivers/of/unittest-data/overlay_base.dts

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index e5ce4b59e162..e33f7818bc6c 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -31,6 +31,8 @@
#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
#include <asm/page.h>

+#include "of_private.h"
+
/*
* of_fdt_limit_memory - limit the number of regions in the /memory node
* @limit: maximum entries
@@ -469,11 +471,11 @@ static int unflatten_dt_nodes(const void *blob,
* Returns NULL on failure or the memory chunk containing the unflattened
* device tree on success.
*/
-static void *__unflatten_device_tree(const void *blob,
- struct device_node *dad,
- struct device_node **mynodes,
- void *(*dt_alloc)(u64 size, u64 align),
- bool detached)
+void *__unflatten_device_tree(const void *blob,
+ struct device_node *dad,
+ struct device_node **mynodes,
+ void *(*dt_alloc)(u64 size, u64 align),
+ bool detached)
{
int size;
void *mem;
@@ -1261,6 +1263,8 @@ void __init unflatten_device_tree(void)

/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
of_alias_scan(early_init_dt_alloc_memory_arch);
+
+ unittest_unflatten_overlay_base();
}

/**
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 18bbb4517e25..cc76b3b81eab 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -55,6 +55,17 @@ static inline int of_property_notify(int action, struct device_node *np,
}
#endif /* CONFIG_OF_DYNAMIC */

+#ifdef CONFIG_OF_UNITTEST
+extern void __init unittest_unflatten_overlay_base(void);
+extern void *__unflatten_device_tree(const void *blob,
+ struct device_node *dad,
+ struct device_node **mynodes,
+ void *(*dt_alloc)(u64 size, u64 align),
+ bool detached);
+#else
+static inline void unittest_unflatten_overlay_base(void) {};
+#endif
+
/**
* General utilities for working with live trees.
*
diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
index 1ac5cc01d627..6e00a9c69e58 100644
--- a/drivers/of/unittest-data/Makefile
+++ b/drivers/of/unittest-data/Makefile
@@ -1,7 +1,18 @@
obj-y += testcases.dtb.o
+obj-y += overlay.dtb.o
+obj-y += overlay_bad_phandle.dtb.o
+obj-y += overlay_base.dtb.o

targets += testcases.dtb testcases.dtb.S
+targets += overlay.dtb overlay.dtb.S
+targets += overlay_bad_phandle.dtb overlay_bad_phandle.dtb.S
+targets += overlay_base.dtb overlay_base.dtb.S

-.SECONDARY: \
- $(obj)/testcases.dtb.S \
- $(obj)/testcases.dtb
+.PRECIOUS: \
+ $(obj)/%.dtb.S \
+ $(obj)/%.dtb
+
+# enable creation of __symbols__ node
+DTC_FLAGS_overlay := -@
+DTC_FLAGS_overlay_bad_phandle := -@
+DTC_FLAGS_overlay_base := -@
diff --git a/drivers/of/unittest-data/overlay.dts b/drivers/of/unittest-data/overlay.dts
new file mode 100644
index 000000000000..6cd7e6a0c13e
--- /dev/null
+++ b/drivers/of/unittest-data/overlay.dts
@@ -0,0 +1,53 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+
+ fragment@0 {
+ target = <&electric_1>;
+
+ __overlay__ {
+ status = "ok";
+
+ hvac_2: hvac-large-1 {
+ compatible = "ot,hvac-large";
+ heat-range = < 40 75 >;
+ cool-range = < 65 80 >;
+ };
+ };
+ };
+
+ fragment@1 {
+ target = <&rides_1>;
+
+ __overlay__ {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ status = "ok";
+
+ ride@200 {
+ compatible = "ot,ferris-wheel";
+ reg = < 0x00000200 0x100 >;
+ hvac-provider = < &hvac_2 >;
+ hvac-thermostat = < 27 32 > ;
+ hvac-zones = < 12 5 >;
+ hvac-zone-names = "operator", "snack-bar";
+ spin-controller = < &spin_ctrl_1 3 >;
+ spin-rph = < 30 >;
+ gondolas = < 16 >;
+ gondola-capacity = < 6 >;
+ };
+ };
+ };
+
+ fragment@2 {
+ target = <&lights_2>;
+
+ __overlay__ {
+ status = "ok";
+ color = "purple", "white", "red", "green";
+ rate = < 3 256 >;
+ };
+ };
+
+};
diff --git a/drivers/of/unittest-data/overlay_bad_phandle.dts b/drivers/of/unittest-data/overlay_bad_phandle.dts
new file mode 100644
index 000000000000..270ee885a623
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_phandle.dts
@@ -0,0 +1,20 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+
+ fragment@0 {
+ target = <&electric_1>;
+
+ __overlay__ {
+
+ // This label should cause an error when the overlay
+ // is applied. There is already a phandle value
+ // in the base tree for motor-1.
+ spin_ctrl_1_conflict: motor-1 {
+ accelerate = < 3 >;
+ decelerate = < 5 >;
+ };
+ };
+ };
+};
diff --git a/drivers/of/unittest-data/overlay_base.dts b/drivers/of/unittest-data/overlay_base.dts
new file mode 100644
index 000000000000..5566b27fb61a
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_base.dts
@@ -0,0 +1,80 @@
+/dts-v1/;
+/plugin/;
+
+/*
+ * Base device tree that overlays will be applied against.
+ *
+ * Do not add any properties in node "/".
+ * Do not add any nodes other than "/testcase-data-2" in node "/".
+ * Do not add anything that would result in dtc creating node "/__fixups__".
+ * dtc will create nodes "/__symbols__" and "/__local_fixups__".
+ */
+
+/ {
+ testcase-data-2 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ electric_1: substation@100 {
+ compatible = "ot,big-volts-control";
+ reg = < 0x00000100 0x100 >;
+ status = "disabled";
+
+ hvac_1: hvac-medium-1 {
+ compatible = "ot,hvac-medium";
+ heat-range = < 50 75 >;
+ cool-range = < 60 80 >;
+ };
+
+ spin_ctrl_1: motor-1 {
+ compatible = "ot,ferris-wheel-motor";
+ spin = "clockwise";
+ };
+
+ spin_ctrl_2: motor-8 {
+ compatible = "ot,roller-coaster-motor";
+ };
+ };
+
+ rides_1: fairway-1 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "ot,rides";
+ status = "disabled";
+ orientation = < 127 >;
+
+ ride@100 {
+ compatible = "ot,roller-coaster";
+ reg = < 0x00000100 0x100 >;
+ hvac-provider = < &hvac_1 >;
+ hvac-thermostat = < 29 > ;
+ hvac-zones = < 14 >;
+ hvac-zone-names = "operator";
+ spin-controller = < &spin_ctrl_2 5 &spin_ctrl_2 7 >;
+ spin-controller-names = "track_1", "track_2";
+ queues = < 2 >;
+ };
+ };
+
+ lights_1: lights@30000 {
+ compatible = "ot,work-lights";
+ reg = < 0x00030000 0x1000 >;
+ status = "disabled";
+ };
+
+ lights_2: lights@40000 {
+ compatible = "ot,show-lights";
+ reg = < 0x00040000 0x1000 >;
+ status = "disabled";
+ rate = < 13 138 >;
+ };
+
+ retail_1: vending@50000 {
+ reg = < 0x00050000 0x1000 >;
+ compatible = "ot,tickets";
+ status = "disabled";
+ };
+
+ };
+};
+
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 62db55b97c10..884f6c1f8ae9 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -8,6 +8,7 @@
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/hashtable.h>
+#include <linux/libfdt.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_irq.h>
@@ -1925,6 +1926,320 @@ static void __init of_unittest_overlay(void)
static inline void __init of_unittest_overlay(void) { }
#endif

+#ifdef CONFIG_OF_OVERLAY
+
+/*
+ * __dtb_ot_begin[] and __dtb_ot_end[] are created by cmd_dt_S_dtb
+ * in scripts/Makefile.lib
+ */
+
+#define OVERLAY_INFO_EXTERN(name) \
+ extern uint8_t __dtb_##name##_begin[]; \
+ extern uint8_t __dtb_##name##_end[]
+
+#define OVERLAY_INFO(name, expected) \
+{ .dtb_begin = __dtb_##name##_begin, \
+ .dtb_end = __dtb_##name##_end, \
+ .expected_result = expected, \
+}
+
+struct overlay_info {
+ uint8_t *dtb_begin;
+ uint8_t *dtb_end;
+ void *data;
+ struct device_node *np_overlay;
+ int expected_result;
+ int overlay_id;
+};
+
+OVERLAY_INFO_EXTERN(overlay_base);
+OVERLAY_INFO_EXTERN(overlay);
+OVERLAY_INFO_EXTERN(overlay_bad_phandle);
+
+/* order of entries is hard-coded into users of overlays[] */
+struct overlay_info overlays[] = {
+ OVERLAY_INFO(overlay_base, -9999),
+ OVERLAY_INFO(overlay, 0),
+ OVERLAY_INFO(overlay_bad_phandle, -EINVAL),
+ {}
+};
+
+static struct device_node *overlay_base_root;
+
+/*
+ * Create base device tree for the overlay unittest.
+ *
+ * This is called from very early boot code.
+ *
+ * Do as much as possible the same way as done in __unflatten_device_tree
+ * and other early boot steps for the normal FDT so that the overlay base
+ * unflattened tree will have the same characteristics as the real tree
+ * (such as having memory allocated by the early allocator). The goal
+ * is to test "the real thing" as much as possible, and test "test setup
+ * code" as little as possible.
+ *
+ * Have to stop before resolving phandles, because that uses kmalloc.
+ */
+void __init unittest_unflatten_overlay_base(void)
+{
+ struct overlay_info *info;
+ u32 data_size;
+ u32 size;
+
+ info = &overlays[0];
+
+ if (info->expected_result != -9999) {
+ pr_err("No dtb 'overlay_base' to attach\n");
+ return;
+ }
+
+ data_size = info->dtb_end - info->dtb_begin;
+ if (!data_size) {
+ pr_err("No dtb 'overlay_base' to attach\n");
+ return;
+ }
+
+ size = fdt_totalsize(info->dtb_begin);
+ if (size != data_size) {
+ pr_err("dtb 'overlay_base' header totalsize != actual size");
+ return;
+ }
+
+ info->data = early_init_dt_alloc_memory_arch(size,
+ roundup_pow_of_two(FDT_V17_SIZE));
+ if (!info->data) {
+ pr_err("alloc for dtb 'overlay_base' failed");
+ return;
+ }
+
+ memcpy(info->data, info->dtb_begin, size);
+
+ __unflatten_device_tree(info->data, NULL, &info->np_overlay,
+ early_init_dt_alloc_memory_arch, true);
+ overlay_base_root = info->np_overlay;
+}
+
+/*
+ * The purpose of of_unittest_overlay_data_add is to add an
+ * overlay in the normal fashion. This is a test of the whole
+ * picture, instead of testing individual elements.
+ *
+ * A secondary purpose is to be able to verify that the contents of
+ * /proc/device-tree/ contains the updated structure and values from
+ * the overlay. That must be verified separately in user space.
+ *
+ * Return 0 on unexpected error.
+ */
+static int __init overlay_data_add(int onum)
+{
+ struct overlay_info *info;
+ int k;
+ int ret;
+ u32 size;
+ u32 size_from_header;
+
+ for (k = 0, info = overlays; info; info++, k++) {
+ if (k == onum)
+ break;
+ }
+ if (onum > k)
+ return 0;
+
+ size = info->dtb_end - info->dtb_begin;
+ if (!size) {
+ pr_err("no overlay to attach, %d\n", onum);
+ ret = 0;
+ }
+
+ size_from_header = fdt_totalsize(info->dtb_begin);
+ if (size_from_header != size) {
+ pr_err("overlay header totalsize != actual size, %d", onum);
+ return 0;
+ }
+
+ /*
+ * Must create permanent copy of FDT because of_fdt_unflatten_tree()
+ * will create pointers to the passed in FDT in the EDT.
+ */
+ info->data = kmemdup(info->dtb_begin, size, GFP_KERNEL);
+ if (!info->data) {
+ pr_err("unable to allocate memory for data, %d\n", onum);
+ return 0;
+ }
+
+ of_fdt_unflatten_tree(info->data, NULL, &info->np_overlay);
+ if (!info->np_overlay) {
+ pr_err("unable to unflatten overlay, %d\n", onum);
+ ret = 0;
+ goto out_free_data;
+ }
+ of_node_set_flag(info->np_overlay, OF_DETACHED);
+
+ ret = of_resolve_phandles(info->np_overlay);
+ if (ret) {
+ pr_err("resolve ot phandles (ret=%d), %d\n", ret, onum);
+ goto out_free_np_overlay;
+ }
+
+ ret = of_overlay_create(info->np_overlay);
+ if (ret < 0) {
+ pr_err("of_overlay_create() (ret=%d), %d\n", ret, onum);
+ goto out_free_np_overlay;
+ } else {
+ info->overlay_id = ret;
+ ret = 0;
+ }
+
+ pr_debug("__dtb_overlay_begin applied, overlay id %d\n", ret);
+
+ goto out;
+
+out_free_np_overlay:
+ /*
+ * info->np_overlay is the unflattened device tree
+ * It has not been spliced into the live tree.
+ */
+
+ /* todo: function to free unflattened device tree */
+
+out_free_data:
+ kfree(info->data);
+
+out:
+ return (ret == info->expected_result);
+}
+
+/*
+ * The purpose of of_unittest_overlay_high_level is to add an overlay
+ * in the normal fashion. This is a test of the whole picture,
+ * instead of individual elements.
+ *
+ * The first part of the function is _not_ normal overlay usage; it is
+ * finishing splicing the base overlay device tree into the live tree.
+ */
+static __init void of_unittest_overlay_high_level(void)
+{
+ struct device_node *last_sibling;
+ struct device_node *np;
+ struct device_node *of_symbols;
+ struct device_node *overlay_base_symbols;
+ struct device_node **pprev;
+ struct property *prop;
+ int ret;
+
+ if (!overlay_base_root) {
+ unittest(0, "overlay_base_root not initialized\n");
+ return;
+ }
+
+ /*
+ * Could not fixup phandles in unittest_unflatten_overlay_base()
+ * because kmalloc() was not yet available.
+ */
+ of_resolve_phandles(overlay_base_root);
+
+ /*
+ * do not allow overlay_base to duplicate any node already in
+ * tree, this greatly simplifies the code
+ */
+
+ /*
+ * remove overlay_base_root node "__local_fixups", after
+ * being used by of_resolve_phandles()
+ */
+ pprev = &overlay_base_root->child;
+ for (np = overlay_base_root->child; np; np = np->sibling) {
+ if (!of_node_cmp(np->name, "__local_fixups__")) {
+ *pprev = np->sibling;
+ break;
+ }
+ pprev = &np->sibling;
+ }
+
+ /* remove overlay_base_root node "__symbols__" if in live tree */
+ of_symbols = of_get_child_by_name(of_root, "__symbols__");
+ if (of_symbols) {
+ /* will have to graft properties from node into live tree */
+ pprev = &overlay_base_root->child;
+ for (np = overlay_base_root->child; np; np = np->sibling) {
+ if (!of_node_cmp(np->name, "__symbols__")) {
+ overlay_base_symbols = np;
+ *pprev = np->sibling;
+ break;
+ }
+ pprev = &np->sibling;
+ }
+ }
+
+ for (np = overlay_base_root->child; np; np = np->sibling) {
+ if (of_get_child_by_name(of_root, np->name)) {
+ unittest(0, "illegal node name in overlay_base %s",
+ np->name);
+ return;
+ }
+ }
+
+ /*
+ * overlay 'overlay_base' is not allowed to have root
+ * properties, so only need to splice nodes into main device tree.
+ *
+ * root node of *overlay_base_root will not be freed, it is lost
+ * memory.
+ */
+
+ for (np = overlay_base_root->child; np; np = np->sibling)
+ np->parent = of_root;
+
+ mutex_lock(&of_mutex);
+
+ for (np = of_root->child; np; np = np->sibling)
+ last_sibling = np;
+
+ if (last_sibling)
+ last_sibling->sibling = overlay_base_root->child;
+ else
+ of_root->child = overlay_base_root->child;
+
+ for_each_of_allnodes_from(overlay_base_root, np)
+ __of_attach_node_sysfs(np);
+
+ if (of_symbols) {
+ for_each_property_of_node(overlay_base_symbols, prop) {
+ ret = __of_add_property(of_symbols, prop);
+ if (ret) {
+ unittest(0,
+ "duplicate property '%s' in overlay_base node __symbols__",
+ prop->name);
+ return;
+ }
+ ret = __of_add_property_sysfs(of_symbols, prop);
+ if (ret) {
+ unittest(0,
+ "unable to add property '%s' in overlay_base node __symbols__ to sysfs",
+ prop->name);
+ return;
+ }
+ }
+ }
+
+ mutex_unlock(&of_mutex);
+
+
+ /* now do the normal overlay usage test */
+
+ unittest(overlay_data_add(1),
+ "Adding overlay 'overlay' failed\n");
+
+ unittest(overlay_data_add(2),
+ "Adding overlay 'overlay_bad_phandle' failed\n");
+}
+
+#else
+
+static inline __init void of_unittest_overlay_high_level(void) {}
+
+#endif
+
static int __init of_unittest(void)
{
struct device_node *np;
@@ -1962,6 +2277,9 @@ static int __init of_unittest(void)
/* Double check linkage after removing testcase data */
of_unittest_check_tree_linkage();

+
+ of_unittest_overlay_high_level();
+
pr_info("end of unittest - %i passed, %i failed\n",
unittest_results.passed, unittest_results.failed);

--
Frank Rowand <frank.rowand@sony.com>