lib: utils: Implement "ranges" property parsing

The "reg" property in a device node may not be the correct address always.
If a parent node defines a "ranges" property, the child address need to be
translated with respect to parents address. If the ranges property is not
present, it will just use 1:1 translation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index aec73a0..bf19ff9 100644 (file)
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -71,10 +71,48 @@ int fdt_find_match(void *fdt, int startoff,
        return SBI_ENODEV;
 }
 
+static int fdt_translate_address(void *fdt, uint64_t reg, int parent,
+                                unsigned long *addr)
+{
+       int i, rlen;
+       int cell_addr, cell_size;
+       const fdt32_t *ranges;
+       uint64_t offset = 0, caddr = 0, paddr = 0, rsize = 0;
+
+       cell_addr = fdt_address_cells(fdt, parent);
+       if (cell_addr < 1)
+               return SBI_ENODEV;
+
+       cell_size = fdt_size_cells(fdt, parent);
+       if (cell_size < 0)
+               return SBI_ENODEV;
+
+       ranges = fdt_getprop(fdt, parent, "ranges", &rlen);
+       if (ranges && rlen > 0) {
+               for (i = 0; i < cell_addr; i++)
+                       caddr = (caddr << 32) | fdt32_to_cpu(*ranges++);
+               for (i = 0; i < cell_addr; i++)
+                       paddr = (paddr << 32) | fdt32_to_cpu(*ranges++);
+               for (i = 0; i < cell_size; i++)
+                       rsize = (rsize << 32) | fdt32_to_cpu(*ranges++);
+               if (reg < caddr || caddr >= (reg + rsize )) {
+                       sbi_printf("invalid address translation\n");
+                       return SBI_ENODEV;
+               }
+               offset = reg - caddr;
+               *addr = paddr + offset;
+       } else {
+               /* No translation required */
+               *addr = reg;
+       }
+
+       return 0;
+}
+
 int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
                           unsigned long *size)
 {
-       int parent, len, i;
+       int parent, len, i, rc;
        int cell_addr, cell_size;
        const fdt32_t *prop_addr, *prop_size;
        uint64_t temp = 0;
@@ -98,7 +136,15 @@ int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
        if (addr) {
                for (i = 0; i < cell_addr; i++)
                        temp = (temp << 32) | fdt32_to_cpu(*prop_addr++);
-               *addr = temp;
+               do {
+                       if (parent < 0)
+                               break;
+                       rc  = fdt_translate_address(fdt, temp, parent, addr);
+                       if (rc)
+                               break;
+                       parent = fdt_parent_offset(fdt, parent);
+                       temp = *addr;
+               } while (1);
        }
        temp = 0;