From d1c6314887c4d6712f7bd9ba7428b6517e7732e0 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 9 Mar 2010 17:39:14 +1100 Subject: libfdt: Implement property iteration functions For ages, we've been talking about adding functions to libfdt to allow iteration through properties. So, finally, here are some. I got bogged down on this for a long time because I didn't want to expose offsets directly to properties to the callers. But without that, attempting to make reasonable iteration functions just became horrible. So eventually, I settled on an interface which does now expose property offsets. fdt_first_property_offset() and fdt_next_property_offset() are used to step through the offsets of the properties starting from a particularly node offset. The details of the property at each offset can then be retrieved with either fdt_get_property_by_offset() or fdt_getprop_by_offset() which have interfaces similar to fdt_get_property() and fdt_getprop() respectively. No explicit testcases are included, but we do use the new functions to reimplement the existing fdt_get_property() function. Signed-off-by: David Gibson This was extracted from the DTC commit: 73dca9ae0b9abe6924ba640164ecce9f8df69c5a Mon Sep 17 00:00:00 2001 Signed-off-by: Gerald Van Baren --- lib/libfdt/fdt.c | 9 ++++ lib/libfdt/fdt_ro.c | 123 ++++++++++++++++++++++++++++++------------- lib/libfdt/libfdt_internal.h | 1 + 3 files changed, 97 insertions(+), 36 deletions(-) (limited to 'lib/libfdt') diff --git a/lib/libfdt/fdt.c b/lib/libfdt/fdt.c index b09ea6f04d..4157b21efd 100644 --- a/lib/libfdt/fdt.c +++ b/lib/libfdt/fdt.c @@ -153,6 +153,15 @@ int _fdt_check_node_offset(const void *fdt, int offset) return offset; } +int _fdt_check_prop_offset(const void *fdt, int offset) +{ + if ((offset < 0) || (offset % FDT_TAGSIZE) + || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP)) + return -FDT_ERR_BADOFFSET; + + return offset; +} + int fdt_next_node(const void *fdt, int offset, int *depth) { int nextoffset = 0; diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c index 91a354e108..1933010fd8 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -109,6 +109,30 @@ int fdt_num_mem_rsv(const void *fdt) return i; } +static int _nextprop(const void *fdt, int offset) +{ + uint32_t tag; + int nextoffset; + + do { + tag = fdt_next_tag(fdt, offset, &nextoffset); + + switch (tag) { + case FDT_END: + if (nextoffset >= 0) + return -FDT_ERR_BADSTRUCTURE; + else + return nextoffset; + + case FDT_PROP: + return offset; + } + offset = nextoffset; + } while (tag == FDT_NOP); + + return -FDT_ERR_NOTFOUND; +} + int fdt_subnode_offset_namelen(const void *fdt, int offset, const char *name, int namelen) { @@ -198,52 +222,66 @@ const char *fdt_get_name(const void *fdt, int nodeoffset, int *len) return NULL; } -const struct fdt_property *fdt_get_property_namelen(const void *fdt, - int nodeoffset, - const char *name, - int namelen, int *lenp) +int fdt_first_property_offset(const void *fdt, int nodeoffset) +{ + int offset; + + if ((offset = _fdt_check_node_offset(fdt, nodeoffset)) < 0) + return offset; + + return _nextprop(fdt, offset); +} + +int fdt_next_property_offset(const void *fdt, int offset) +{ + if ((offset = _fdt_check_prop_offset(fdt, offset)) < 0) + return offset; + + return _nextprop(fdt, offset); +} + +const struct fdt_property *fdt_get_property_by_offset(const void *fdt, + int offset, + int *lenp) { - uint32_t tag; - const struct fdt_property *prop; - int offset, nextoffset; int err; + const struct fdt_property *prop; - if (((err = fdt_check_header(fdt)) != 0) - || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0)) - goto fail; + if ((err = _fdt_check_prop_offset(fdt, offset)) < 0) { + if (lenp) + *lenp = err; + return NULL; + } - nextoffset = err; - do { - offset = nextoffset; + prop = _fdt_offset_ptr(fdt, offset); - tag = fdt_next_tag(fdt, offset, &nextoffset); - switch (tag) { - case FDT_END: - if (nextoffset < 0) - err = nextoffset; - else - /* FDT_END tag with unclosed nodes */ - err = -FDT_ERR_BADSTRUCTURE; - goto fail; + if (lenp) + *lenp = fdt32_to_cpu(prop->len); - case FDT_PROP: - prop = _fdt_offset_ptr(fdt, offset); - if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff), - name, namelen)) { - /* Found it! */ - if (lenp) - *lenp = fdt32_to_cpu(prop->len); - - return prop; - } + return prop; +} + +const struct fdt_property *fdt_get_property_namelen(const void *fdt, + int offset, + const char *name, + int namelen, int *lenp) +{ + for (offset = fdt_first_property_offset(fdt, offset); + (offset >= 0); + (offset = fdt_next_property_offset(fdt, offset))) { + const struct fdt_property *prop; + + if (!(prop = fdt_get_property_by_offset(fdt, offset, lenp))) { + offset = -FDT_ERR_INTERNAL; break; } - } while ((tag != FDT_BEGIN_NODE) && (tag != FDT_END_NODE)); + if (_fdt_string_eq(fdt, fdt32_to_cpu(prop->nameoff), + name, namelen)) + return prop; + } - err = -FDT_ERR_NOTFOUND; - fail: if (lenp) - *lenp = err; + *lenp = offset; return NULL; } @@ -267,6 +305,19 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, return prop->data; } +const void *fdt_getprop_by_offset(const void *fdt, int offset, + const char **namep, int *lenp) +{ + const struct fdt_property *prop; + + prop = fdt_get_property_by_offset(fdt, offset, lenp); + if (!prop) + return NULL; + if (namep) + *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); + return prop->data; +} + const void *fdt_getprop(const void *fdt, int nodeoffset, const char *name, int *lenp) { diff --git a/lib/libfdt/libfdt_internal.h b/lib/libfdt/libfdt_internal.h index d2dcbd65ee..381133ba81 100644 --- a/lib/libfdt/libfdt_internal.h +++ b/lib/libfdt/libfdt_internal.h @@ -63,6 +63,7 @@ } int _fdt_check_node_offset(const void *fdt, int offset); +int _fdt_check_prop_offset(const void *fdt, int offset); const char *_fdt_find_string(const char *strtab, int tabsize, const char *s); int _fdt_node_end_offset(void *fdt, int nodeoffset); -- cgit v1.2.1