From 1209e2727c60d052ce875aa39bb8b9ba2edbfbdf Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Sun, 10 Nov 2013 10:27:04 -0700 Subject: [PATCH] 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 Signed-off-by: Simon Glass Reviewed-by: Hung-ying Tyan --- arch/sandbox/cpu/start.c | 49 ++++- arch/sandbox/cpu/state.c | 331 +++++++++++++++++++++++++++++++ arch/sandbox/include/asm/state.h | 114 +++++++++++ 3 files changed, 490 insertions(+), 4 deletions(-) diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c index 452f2a98f3..1df21d49fa 100644 --- a/arch/sandbox/cpu/start.c +++ b/arch/sandbox/cpu/start.c @@ -126,19 +126,56 @@ static int sandbox_cmdline_cb_memory(struct sandbox_state *state, SANDBOX_CMDLINE_OPT_SHORT(memory, 'm', 1, "Read/write ram_buf memory contents from file"); +static int sandbox_cmdline_cb_state(struct sandbox_state *state, + const char *arg) +{ + state->state_fname = arg; + return 0; +} +SANDBOX_CMDLINE_OPT_SHORT(state, 's', 1, "Specify the sandbox state FDT"); + +static int sandbox_cmdline_cb_read(struct sandbox_state *state, + const char *arg) +{ + state->read_state = true; + return 0; +} +SANDBOX_CMDLINE_OPT_SHORT(read, 'r', 0, "Read the state FDT on startup"); + +static int sandbox_cmdline_cb_write(struct sandbox_state *state, + const char *arg) +{ + state->write_state = true; + return 0; +} +SANDBOX_CMDLINE_OPT_SHORT(write, 'w', 0, "Write state FDT on exit"); + +static int sandbox_cmdline_cb_ignore_missing(struct sandbox_state *state, + const char *arg) +{ + state->ignore_missing_state_on_read = true; + return 0; +} +SANDBOX_CMDLINE_OPT_SHORT(ignore_missing, 'n', 0, + "Ignore missing state on read"); + int main(int argc, char *argv[]) { struct sandbox_state *state; - int err; + int ret; - err = state_init(); - if (err) - return err; + ret = state_init(); + if (ret) + goto err; state = state_get_current(); if (os_parse_args(state, argc, argv)) return 1; + ret = sandbox_read_state(state, state->state_fname); + if (ret) + goto err; + /* Do pre- and post-relocation init */ board_init_f(0); @@ -146,4 +183,8 @@ int main(int argc, char *argv[]) /* NOTREACHED - board_init_r() does not return */ return 0; + +err: + printf("Error %d\n", ret); + return 1; } diff --git a/arch/sandbox/cpu/state.c b/arch/sandbox/cpu/state.c index 0380fe2791..a145808a52 100644 --- a/arch/sandbox/cpu/state.c +++ b/arch/sandbox/cpu/state.c @@ -4,6 +4,8 @@ */ #include +#include +#include #include #include @@ -16,6 +18,324 @@ void state_record_exit(enum exit_type_id exit_type) 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 @@ int state_uninit(void) } } + 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; } diff --git a/arch/sandbox/include/asm/state.h b/arch/sandbox/include/asm/state.h index e4b4c72463..e8e4fea1b5 100644 --- a/arch/sandbox/include/asm/state.h +++ b/arch/sandbox/include/asm/state.h @@ -8,6 +8,7 @@ #include #include +#include /* How we exited U-Boot */ enum exit_type_id { @@ -34,12 +35,82 @@ struct sandbox_state { unsigned int ram_size; /* Size of RAM buffer */ const char *ram_buf_fname; /* Filename to use for RAM buffer */ bool write_ram_buf; /* Write RAM buffer on exit */ + const char *state_fname; /* File containing sandbox state */ + void *state_fdt; /* Holds saved state for sandbox */ + bool read_state; /* Read sandbox state on startup */ + bool write_state; /* Write sandbox state on exit */ + bool ignore_missing_state_on_read; /* No error if state missing */ /* Pointer to information for each SPI bus/cs */ struct sandbox_spi_info spi[CONFIG_SANDBOX_SPI_MAX_BUS] [CONFIG_SANDBOX_SPI_MAX_CS]; }; +/* Minimum space we guarantee in the state FDT when calling read/write*/ +#define SANDBOX_STATE_MIN_SPACE 0x1000 + +/** + * struct sandbox_state_io - methods to saved/restore sandbox state + * @name: Name of of the device tree node, also the name of the variable + * holding this data so it should be an identifier (use underscore + * instead of minus) + * @compat: Compatible string for the node containing this state + * + * @read: Function to read state from FDT + * If data is available, then blob and node will provide access to it. If + * not (blob == NULL and node == -1) this function should set up an empty + * data set for start-of-day. + * @param blob: Pointer to device tree blob, or NULL if no data to read + * @param node: Node offset to read from + * @return 0 if OK, -ve on error + * + * @write: Function to write state to FDT + * The caller will ensure that there is a node ready for the state. The + * node may already contain the old state, in which case it should be + * overridden. There is guaranteed to be SANDBOX_STATE_MIN_SPACE bytes + * of free space, so error checking is not required for fdt_setprop...() + * calls which add up to less than this much space. + * + * For adding larger properties, use state_setprop(). + * + * @param blob: Device tree blob holding state + * @param node: Node to write our state into + * + * Note that it is possible to save data as large blobs or as individual + * hierarchical properties. However, unless you intend to keep state files + * around for a long time and be able to run an old state file on a new + * sandbox, it might not be worth using individual properties for everything. + * This is certainly supported, it is just a matter of the effort you wish + * to put into the state read/write feature. + */ +struct sandbox_state_io { + const char *name; + const char *compat; + int (*write)(void *blob, int node); + int (*read)(const void *blob, int node); +}; + +/** + * SANDBOX_STATE_IO - Declare sandbox state to read/write + * + * Sandbox permits saving state from one run and restoring it in another. This + * allows the test system to retain state between runs and thus better + * emulate a real system. Examples of state that might be useful to save are + * the emulated GPIOs pin settings, flash memory contents and TPM private + * data. U-Boot memory contents is dealth with separately since it is large + * and it is not normally useful to save it (since a normal system does not + * preserve DRAM between runs). See the '-m' option for this. + * + * See struct sandbox_state_io above for member documentation. + */ +#define SANDBOX_STATE_IO(_name, _compat, _read, _write) \ + ll_entry_declare(struct sandbox_state_io, _name, state_io) = { \ + .name = __stringify(_name), \ + .read = _read, \ + .write = _write, \ + .compat = _compat, \ + } + /** * Record the exit type to be reported by the test program. * @@ -54,6 +125,49 @@ void state_record_exit(enum exit_type_id exit_type); */ struct sandbox_state *state_get_current(void); +/** + * Read the sandbox state from the supplied device tree file + * + * This calls all registered state handlers to read in the sandbox state + * from a previous test run. + * + * @param state Sandbox state to update + * @param fname Filename of device tree file to read from + * @return 0 if OK, -ve on error + */ +int sandbox_read_state(struct sandbox_state *state, const char *fname); + +/** + * Write the sandbox state to the supplied device tree file + * + * This calls all registered state handlers to write out the sandbox state + * so that it can be preserved for a future test run. + * + * If the file exists it is overwritten. + * + * @param state Sandbox state to update + * @param fname Filename of device tree file to write to + * @return 0 if OK, -ve on error + */ +int sandbox_write_state(struct sandbox_state *state, const char *fname); + +/** + * Add a property to a sandbox state node + * + * This is equivalent to fdt_setprop except that it automatically enlarges + * the device tree if necessary. That means it is safe to write any amount + * of data here. + * + * This function can only be called from within struct sandbox_state_io's + * ->write method, i.e. within state I/O drivers. + * + * @param node Device tree node to write to + * @param prop_name Property to write + * @param data Data to write into property + * @param size Size of data to write into property + */ +int state_setprop(int node, const char *prop_name, const void *data, int size); + /** * Initialize the test system state */ -- 2.25.1