sandbox: Add facility to save/restore sandbox state
It is often useful to be able to save out the state from a sandbox test
run, for analysis or to restore it later to continue a test. Add generic
infrastructure for doing this using a device tree binary file. This is
a flexible tagged file format which is already supported by U-Boot, and
it supports hierarchy if needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Hung-ying Tyan <tyanh@chromium.org>
diff --git a/arch/sandbox/cpu/state.c b/arch/sandbox/cpu/state.c
index 0380fe2..a145808 100644
--- a/arch/sandbox/cpu/state.c
+++ b/arch/sandbox/cpu/state.c
@@ -4,6 +4,8 @@
*/
#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
#include <os.h>
#include <asm/state.h>
@@ -16,6 +18,324 @@
state->exit_type = exit_type;
}
+static int state_ensure_space(int extra_size)
+{
+ void *blob = state->state_fdt;
+ int used, size, free;
+ void *buf;
+ int ret;
+
+ used = fdt_off_dt_strings(blob) + fdt_size_dt_strings(blob);
+ size = fdt_totalsize(blob);
+ free = size - used;
+ if (free > extra_size)
+ return 0;
+
+ size = used + extra_size;
+ buf = os_malloc(size);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = fdt_open_into(blob, buf, size);
+ if (ret) {
+ os_free(buf);
+ return -EIO;
+ }
+
+ os_free(blob);
+ state->state_fdt = buf;
+ return 0;
+}
+
+static int state_read_file(struct sandbox_state *state, const char *fname)
+{
+ int size;
+ int ret;
+ int fd;
+
+ size = os_get_filesize(fname);
+ if (size < 0) {
+ printf("Cannot find sandbox state file '%s'\n", fname);
+ return -ENOENT;
+ }
+ state->state_fdt = os_malloc(size);
+ if (!state->state_fdt) {
+ puts("No memory to read sandbox state\n");
+ return -ENOMEM;
+ }
+ fd = os_open(fname, OS_O_RDONLY);
+ if (fd < 0) {
+ printf("Cannot open sandbox state file '%s'\n", fname);
+ ret = -EPERM;
+ goto err_open;
+ }
+ if (os_read(fd, state->state_fdt, size) != size) {
+ printf("Cannot read sandbox state file '%s'\n", fname);
+ ret = -EIO;
+ goto err_read;
+ }
+ os_close(fd);
+
+ return 0;
+err_read:
+ os_close(fd);
+err_open:
+ os_free(state->state_fdt);
+ state->state_fdt = NULL;
+
+ return ret;
+}
+
+/***
+ * sandbox_read_state_nodes() - Read state associated with a driver
+ *
+ * This looks through all compatible nodes and calls the read function on
+ * each one, to read in the state.
+ *
+ * If nothing is found, it still calls the read function once, to set up a
+ * single global state for that driver.
+ *
+ * @state: Sandbox state
+ * @io: Method to use for reading state
+ * @blob: FDT containing state
+ * @return 0 if OK, -EINVAL if the read function returned failure
+ */
+int sandbox_read_state_nodes(struct sandbox_state *state,
+ struct sandbox_state_io *io, const void *blob)
+{
+ int count;
+ int node;
+ int ret;
+
+ debug(" - read %s\n", io->name);
+ if (!io->read)
+ return 0;
+
+ node = -1;
+ count = 0;
+ while (blob) {
+ node = fdt_node_offset_by_compatible(blob, node, io->compat);
+ if (node < 0)
+ return 0; /* No more */
+ debug(" - read node '%s'\n", fdt_get_name(blob, node, NULL));
+ ret = io->read(blob, node);
+ if (ret) {
+ printf("Unable to read state for '%s'\n", io->compat);
+ return -EINVAL;
+ }
+ count++;
+ }
+
+ /*
+ * If we got no saved state, call the read function once without a
+ * node, to set up the global state.
+ */
+ if (count == 0) {
+ debug(" - read global\n");
+ ret = io->read(NULL, -1);
+ if (ret) {
+ printf("Unable to read global state for '%s'\n",
+ io->name);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+int sandbox_read_state(struct sandbox_state *state, const char *fname)
+{
+ struct sandbox_state_io *io;
+ const void *blob;
+ bool got_err;
+ int ret;
+
+ if (state->read_state && fname) {
+ ret = state_read_file(state, fname);
+ if (ret == -ENOENT && state->ignore_missing_state_on_read)
+ ret = 0;
+ if (ret)
+ return ret;
+ }
+
+ /* Call all the state read funtcions */
+ got_err = false;
+ blob = state->state_fdt;
+ io = ll_entry_start(struct sandbox_state_io, state_io);
+ for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
+ ret = sandbox_read_state_nodes(state, io, blob);
+ if (ret < 0)
+ got_err = true;
+ }
+
+ if (state->read_state && fname) {
+ debug("Read sandbox state from '%s'%s\n", fname,
+ got_err ? " (with errors)" : "");
+ }
+
+ return got_err ? -1 : 0;
+}
+
+/***
+ * sandbox_write_state_node() - Write state associated with a driver
+ *
+ * This calls the write function to write out global state for that driver.
+ *
+ * TODO(sjg@chromium.org): Support writing out state from multiple drivers
+ * of the same time. We don't need this yet,and it will be much easier to
+ * do when driver model is available.
+ *
+ * @state: Sandbox state
+ * @io: Method to use for writing state
+ * @return 0 if OK, -EIO if there is a fatal error (such as out of space
+ * for adding the data), -EINVAL if the write function failed.
+ */
+int sandbox_write_state_node(struct sandbox_state *state,
+ struct sandbox_state_io *io)
+{
+ void *blob;
+ int node;
+ int ret;
+
+ if (!io->write)
+ return 0;
+
+ ret = state_ensure_space(SANDBOX_STATE_MIN_SPACE);
+ if (ret) {
+ printf("Failed to add more space for state\n");
+ return -EIO;
+ }
+
+ /* The blob location can change when the size increases */
+ blob = state->state_fdt;
+ node = fdt_node_offset_by_compatible(blob, -1, io->compat);
+ if (node == -FDT_ERR_NOTFOUND) {
+ node = fdt_add_subnode(blob, 0, io->name);
+ if (node < 0) {
+ printf("Cannot create node '%s': %s\n", io->name,
+ fdt_strerror(node));
+ return -EIO;
+ }
+
+ if (fdt_setprop_string(blob, node, "compatible", io->compat)) {
+ puts("Cannot set compatible\n");
+ return -EIO;
+ }
+ } else if (node < 0) {
+ printf("Cannot access node '%s': %s\n", io->name,
+ fdt_strerror(node));
+ return -EIO;
+ }
+ debug("Write state for '%s' to node %d\n", io->compat, node);
+ ret = io->write(blob, node);
+ if (ret) {
+ printf("Unable to write state for '%s'\n", io->compat);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int sandbox_write_state(struct sandbox_state *state, const char *fname)
+{
+ struct sandbox_state_io *io;
+ bool got_err;
+ int size;
+ int ret;
+ int fd;
+
+ /* Create a state FDT if we don't have one */
+ if (!state->state_fdt) {
+ size = 0x4000;
+ state->state_fdt = os_malloc(size);
+ if (!state->state_fdt) {
+ puts("No memory to create FDT\n");
+ return -ENOMEM;
+ }
+ ret = fdt_create_empty_tree(state->state_fdt, size);
+ if (ret < 0) {
+ printf("Cannot create empty state FDT: %s\n",
+ fdt_strerror(ret));
+ ret = -EIO;
+ goto err_create;
+ }
+ }
+
+ /* Call all the state write funtcions */
+ got_err = false;
+ io = ll_entry_start(struct sandbox_state_io, state_io);
+ ret = 0;
+ for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
+ ret = sandbox_write_state_node(state, io);
+ if (ret == -EIO)
+ break;
+ else if (ret)
+ got_err = true;
+ }
+
+ if (ret == -EIO) {
+ printf("Could not write sandbox state\n");
+ goto err_create;
+ }
+
+ ret = fdt_pack(state->state_fdt);
+ if (ret < 0) {
+ printf("Cannot pack state FDT: %s\n", fdt_strerror(ret));
+ ret = -EINVAL;
+ goto err_create;
+ }
+ size = fdt_totalsize(state->state_fdt);
+ fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT);
+ if (fd < 0) {
+ printf("Cannot open sandbox state file '%s'\n", fname);
+ ret = -EIO;
+ goto err_create;
+ }
+ if (os_write(fd, state->state_fdt, size) != size) {
+ printf("Cannot write sandbox state file '%s'\n", fname);
+ ret = -EIO;
+ goto err_write;
+ }
+ os_close(fd);
+
+ debug("Wrote sandbox state to '%s'%s\n", fname,
+ got_err ? " (with errors)" : "");
+
+ return 0;
+err_write:
+ os_close(fd);
+err_create:
+ os_free(state->state_fdt);
+
+ return ret;
+}
+
+int state_setprop(int node, const char *prop_name, const void *data, int size)
+{
+ void *blob;
+ int len;
+ int ret;
+
+ fdt_getprop(state->state_fdt, node, prop_name, &len);
+
+ /* Add space for the new property, its name and some overhead */
+ ret = state_ensure_space(size - len + strlen(prop_name) + 32);
+ if (ret)
+ return ret;
+
+ /* This should succeed, barring a mutiny */
+ blob = state->state_fdt;
+ ret = fdt_setprop(blob, node, prop_name, data, size);
+ if (ret) {
+ printf("%s: Unable to set property '%s' in node '%s': %s\n",
+ __func__, prop_name, fdt_get_name(blob, node, NULL),
+ fdt_strerror(ret));
+ return -ENOSPC;
+ }
+
+ return 0;
+}
+
struct sandbox_state *state_get_current(void)
{
assert(state);
@@ -53,5 +373,16 @@
}
}
+ if (state->write_state) {
+ if (sandbox_write_state(state, state->state_fname)) {
+ printf("Failed to write sandbox state\n");
+ return -1;
+ }
+ }
+
+ if (state->state_fdt)
+ os_free(state->state_fdt);
+ memset(state, '\0', sizeof(*state));
+
return 0;
}