On Fri, 8 Mar 2019 at 13:11, Thierry Reding thierry.reding@gmail.com wrote:
From: Thierry Reding treding@nvidia.com
This function can be used to add subnodes in the /reserved-memory node.
Signed-off-by: Thierry Reding treding@nvidia.com
include/fdtdec.h | 17 +++++ lib/fdtdec.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 175 insertions(+)
I think an example would be useful, or perhaps a pointer to some docs (perhaps DT spec?) showing how this function is used?
Reviewed-by: Simon Glass sjg@chromium.org
diff --git a/include/fdtdec.h b/include/fdtdec.h index 997103a87cdf..5c9108ced571 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -979,6 +979,23 @@ int fdtdec_get_max_phandle(const void *blob, uint32_t *maxp); */ 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 9195a05d1129..a8b35c144ae0 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -1287,6 +1287,164 @@ int fdtdec_set_phandle(void *blob, int node, uint32_t phandle) return 0; }
+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(na);err = fdt_setprop(blob, node, "#address-cells", &value, sizeof(value));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;return node;+}
+static void fdt_addr_unpack(fdt_addr_t addr, fdt32_t *upper, fdt32_t *lower) +{ +#ifdef CONFIG_PHYS_64BIT
*upper = addr >> 32;+#else
*upper = 0;+#endif
*lower = addr;+}
+static void fdt_size_unpack(fdt_size_t size, fdt32_t *upper, fdt32_t *lower) +{ +#ifdef CONFIG_PHYS_64BIT
*upper = size >> 32;+#else
*upper = 0;+#endif
*lower = size;+}
+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_address_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) {printf("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.*/fdt_addr_unpack(carveout->start, &upper, &lower);if (na > 1)snprintf(name, sizeof(name), "%s@%x,%x", basename, upper,lower);else {if (upper) {printf("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;/** Generate a new phandle for the reserved-memory node. Look up the* highest phandle number currently in used and use the next higher* one.*/err = fdtdec_get_max_phandle(blob, &phandle);if (err < 0)return err;err = fdtdec_set_phandle(blob, node, phandle + 1);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 */fdt_size_unpack(carveout->end - carveout->start, &upper, &lower);if (ns > 1)*ptr++ = cpu_to_fdt32(upper);*ptr++ = cpu_to_fdt32(lower);err = fdt_setprop(blob, node, "reg", cells, ptr - cells);if (err < 0)return err;/* return the phandle for the new node for the caller to use */if (phandlep)*phandlep = phandle + 1;return 0;+}
int fdtdec_setup(void) {
#if CONFIG_IS_ENABLED(OF_CONTROL)
2.20.1