From: Thierry Reding treding@nvidia.com
This function can be used to add subnodes in the /reserved-memory node.
Reviewed-by: Simon Glass sjg@chromium.org Signed-off-by: Thierry Reding treding@nvidia.com --- Changes in v2: - split fdt_{addr,size}_unpack() helpers into separate patch - use name@x,y notation only if the upper cell is > 0 - use debug() instead of printf() to save code size - properly compute number of cells in reg property - fix carveout size computations, was off by one - use #size-cells where appropriate
include/fdtdec.h | 17 ++++++ lib/fdtdec.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 148 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h index eb076fc24bc9..5c23a9e5f104 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -1004,6 +1004,23 @@ int fdtdec_generate_phandle(const void *blob, uint32_t *phandle); */ int fdtdec_set_phandle(void *blob, int node, uint32_t phandle);
+/** + * fdtdec_add_reserved_memory() - add or find a reserved-memory node + * + * If a reserved-memory node already exists for the given carveout, a phandle + * for that node will be returned. Otherwise a new node will be created and a + * phandle corresponding to it will be returned. + * + * @param blob FDT blob + * @param basename base name of the node to create + * @param carveout information about the carveout region + * @param phandlep return location for the phandle of the carveout region + * @return 0 on success or a negative error code on failure + */ +int fdtdec_add_reserved_memory(void *blob, const char *basename, + const struct fdt_memory *carveout, + uint32_t *phandlep); + /** * Set up the device tree ready for use */ diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 04d242cdf38e..bef331df9a08 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -1278,6 +1278,137 @@ int fdtdec_set_phandle(void *blob, int node, uint32_t phandle) return fdt_setprop(blob, node, "phandle", &value, sizeof(value)); }
+static int fdtdec_init_reserved_memory(void *blob) +{ + int na, ns, node, err; + fdt32_t value; + + /* inherit #address-cells and #size-cells from the root node */ + na = fdt_address_cells(blob, 0); + ns = fdt_size_cells(blob, 0); + + node = fdt_add_subnode(blob, 0, "reserved-memory"); + if (node < 0) + return node; + + err = fdt_setprop(blob, node, "ranges", NULL, 0); + if (err < 0) + return err; + + value = cpu_to_fdt32(ns); + + err = fdt_setprop(blob, node, "#size-cells", &value, sizeof(value)); + if (err < 0) + return err; + + value = cpu_to_fdt32(na); + + err = fdt_setprop(blob, node, "#address-cells", &value, sizeof(value)); + if (err < 0) + return err; + + return node; +} + +int fdtdec_add_reserved_memory(void *blob, const char *basename, + const struct fdt_memory *carveout, + uint32_t *phandlep) +{ + fdt32_t cells[4] = {}, *ptr = cells; + uint32_t upper, lower, phandle; + int parent, node, na, ns, err; + char name[64]; + + /* create an empty /reserved-memory node if one doesn't exist */ + parent = fdt_path_offset(blob, "/reserved-memory"); + if (parent < 0) { + parent = fdtdec_init_reserved_memory(blob); + if (parent < 0) + return parent; + } + + /* only 1 or 2 #address-cells and #size-cells are supported */ + na = fdt_address_cells(blob, parent); + if (na < 1 || na > 2) + return -FDT_ERR_BADNCELLS; + + ns = fdt_size_cells(blob, parent); + if (ns < 1 || ns > 2) + return -FDT_ERR_BADNCELLS; + + /* find a matching node and return the phandle to that */ + fdt_for_each_subnode(node, blob, parent) { + const char *name = fdt_get_name(blob, node, NULL); + phys_addr_t addr, size; + + addr = fdtdec_get_addr_size(blob, node, "reg", &size); + if (addr == FDT_ADDR_T_NONE) { + debug("failed to read address/size for %s\n", name); + continue; + } + + if (addr == carveout->start && (addr + size) == carveout->end) { + *phandlep = fdt_get_phandle(blob, node); + return 0; + } + } + + /* + * Unpack the start address and generate the name of the new node + * base on the basename and the unit-address. + */ + lower = fdt_addr_unpack(carveout->start, &upper); + + if (na > 1 && upper > 0) + snprintf(name, sizeof(name), "%s@%x,%x", basename, upper, + lower); + else { + if (upper > 0) { + debug("address %08x:%08x exceeds addressable space\n", + upper, lower); + return -FDT_ERR_BADVALUE; + } + + snprintf(name, sizeof(name), "%s@%x", basename, lower); + } + + node = fdt_add_subnode(blob, parent, name); + if (node < 0) + return node; + + err = fdtdec_generate_phandle(blob, &phandle); + if (err < 0) + return err; + + err = fdtdec_set_phandle(blob, node, phandle); + if (err < 0) + return err; + + /* store one or two address cells */ + if (na > 1) + *ptr++ = cpu_to_fdt32(upper); + + *ptr++ = cpu_to_fdt32(lower); + + /* store one or two size cells */ + lower = fdt_size_unpack(carveout->end - carveout->start + 1, &upper); + + if (ns > 1) + *ptr++ = cpu_to_fdt32(upper); + + *ptr++ = cpu_to_fdt32(lower); + + err = fdt_setprop(blob, node, "reg", cells, (na + ns) * sizeof(*cells)); + if (err < 0) + return err; + + /* return the phandle for the new node for the caller to use */ + if (phandlep) + *phandlep = phandle; + + return 0; +} + int fdtdec_setup(void) { #if CONFIG_IS_ENABLED(OF_CONTROL)