diff options
| -rw-r--r-- | sys/dev/ofw/fdt.c | 107 |
1 files changed, 102 insertions, 5 deletions
diff --git a/sys/dev/ofw/fdt.c b/sys/dev/ofw/fdt.c index 4cebbb4cc96..1ad9611f670 100644 --- a/sys/dev/ofw/fdt.c +++ b/sys/dev/ofw/fdt.c @@ -1,4 +1,4 @@ -/* $OpenBSD: fdt.c,v 1.6 2016/04/03 13:48:07 patrick Exp $ */ +/* $OpenBSD: fdt.c,v 1.7 2016/04/06 11:42:50 patrick Exp $ */ /* * Copyright (c) 2009 Dariusz Swiderski <sfires@sfires.net> @@ -34,6 +34,7 @@ void *skip_node(void *); void *fdt_parent_node_recurse(void *, void *); int fdt_node_property_int(void *, char *, int *); int fdt_node_property_ints(void *, char *, int *, int); +int fdt_translate_memory_address(void *, struct fdt_memory *); #ifdef DEBUG void fdt_print_node_recurse(void *, int); #endif @@ -390,6 +391,105 @@ fdt_parent_node(void *node) } /* + * Translate memory address depending on parent's range. + * + * Ranges are a way of mapping one address to another. This ranges attribute + * is set on a node's parent. This means if a node does not have a parent, + * there's nothing to translate. If it does have a parent and the parent does + * not have a ranges attribute, there's nothing to translate either. + * + * If the parent has a ranges attribute and the attribute is not empty, the + * node's memory address has to be in one of the given ranges. This range is + * then used to translate the memory address. + * + * If the parent has a ranges attribute, but the attribute is empty, there's + * nothing to translate. But it's not a translation barrier. It can be treated + * as a simple 1:1 mapping. + * + * Translation does not end here. We need to check if the parent's parent also + * has a ranges attribute and ask the same questions again. + */ +int +fdt_translate_memory_address(void *node, struct fdt_memory *mem) +{ + void *parent; + int pac, psc, ac, sc, ret, rlen, rone, *range; + uint64_t from, to, size; + + /* No parent, no translation. */ + parent = fdt_parent_node(node); + if (parent == NULL) + return 0; + + /* Extract ranges property from node. */ + rlen = fdt_node_property(node, "ranges", (char **)&range) / sizeof(int); + + /* No ranges means translation barrier. Translation stops here. */ + if (range == NULL) + return 0; + + /* Empty ranges means 1:1 mapping. Continue translation on parent. */ + if (rlen <= 0) + return fdt_translate_memory_address(parent, mem); + + /* We only support 32-bit (1), and 64-bit (2) wide addresses here. */ + ret = fdt_node_property_int(parent, "#address-cells", &pac); + if (ret != 1 || pac <= 0 || pac > 2) + return EINVAL; + + /* We only support 32-bit (1), and 64-bit (2) wide sizes here. */ + ret = fdt_node_property_int(parent, "#size-cells", &psc); + if (ret != 1 || psc <= 0 || psc > 2) + return EINVAL; + + /* We only support 32-bit (1), and 64-bit (2) wide addresses here. */ + ret = fdt_node_property_int(node, "#address-cells", &ac); + if (ret <= 0) + ac = pac; + else if (ret > 1 || ac <= 0 || ac > 2) + return EINVAL; + + /* We only support 32-bit (1), and 64-bit (2) wide sizes here. */ + ret = fdt_node_property_int(node, "#size-cells", &sc); + if (ret <= 0) + sc = psc; + else if (ret > 1 || sc <= 0 || sc > 2) + return EINVAL; + + /* Must have at least one range. */ + rone = pac + ac + sc; + if (rlen < rone) + return ESRCH; + + /* For each range. */ + for (; rlen >= rone; rlen -= rone, range += rone) { + /* Extract from and size, so we can see if we fit. */ + from = betoh32(range[0]); + if (ac == 2) + from = (from << 32) + betoh32(range[1]); + size = betoh32(range[ac + pac]); + if (sc == 2) + size = (size << 32) + betoh32(range[ac + pac + 1]); + + /* Try next, if we're not in the range. */ + if (mem->addr < from || (mem->addr + mem->size) > (from + size)) + continue; + + /* All good, extract to address and translate. */ + to = betoh32(range[ac]); + if (pac == 2) + to = (to << 32) + betoh32(range[ac + 1]); + + mem->addr -= from; + mem->addr += to; + return fdt_translate_memory_address(parent, mem); + } + + /* To be successful, we must have returned in the for-loop. */ + return ESRCH; +} + +/* * Parse the memory address and size of a node. */ int @@ -429,10 +529,7 @@ fdt_get_memory_address(void *node, int idx, struct fdt_memory *mem) if (sc == 2) mem->size = (mem->size << 32) + betoh32(in[off + ac + 1]); - /* TODO: translate memory address in ranges */ - //return fdt_translate_memory_address(parent, mem); - - return 0; + return fdt_translate_memory_address(parent, mem); } #ifdef DEBUG |