[src/trunk]: src/sys/dev/fdt The "ranges" property provides a means of transl...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/88981bb0092d
branches:  trunk
changeset: 824333:88981bb0092d
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Fri Jun 02 01:07:53 2017 +0000

description:
The "ranges" property provides a means of translating between the
address space of a bus and the address space of the bus node's parent.
Translate addresses using these rules in fdtbus_get_reg{,64}.

diffstat:

 sys/dev/fdt/fdt_subr.c |  113 ++++++++++++++++++++++++++++++------------------
 1 files changed, 71 insertions(+), 42 deletions(-)

diffs (164 lines):

diff -r e164609f023a -r 88981bb0092d sys/dev/fdt/fdt_subr.c
--- a/sys/dev/fdt/fdt_subr.c    Fri Jun 02 00:55:26 2017 +0000
+++ b/sys/dev/fdt/fdt_subr.c    Fri Jun 02 01:07:53 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: fdt_subr.c,v 1.12 2017/05/29 23:13:03 jmcneill Exp $ */
+/* $NetBSD: fdt_subr.c,v 1.13 2017/06/02 01:07:53 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2015 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fdt_subr.c,v 1.12 2017/05/29 23:13:03 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fdt_subr.c,v 1.13 2017/06/02 01:07:53 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -87,11 +87,7 @@
 {
        uint32_t addr_cells;
 
-       const int parent = OF_parent(phandle);
-       if (parent == -1)
-               return -1;
-
-       if (of_getprop_uint32(parent, "#address-cells", &addr_cells))
+       if (of_getprop_uint32(phandle, "#address-cells", &addr_cells))
                addr_cells = 2;
 
        return addr_cells;
@@ -102,11 +98,7 @@
 {
        uint32_t size_cells;
 
-       const int parent = OF_parent(phandle);
-       if (parent == -1)
-               return -1;
-
-       if (of_getprop_uint32(parent, "#size-cells", &size_cells))
+       if (of_getprop_uint32(phandle, "#size-cells", &size_cells))
                size_cells = 0;
 
        return size_cells;
@@ -159,6 +151,61 @@
        return true;
 }
 
+static uint64_t
+fdtbus_get_cells(const uint8_t *buf, int cells)
+{
+       switch (cells) {
+       case 0:         return 0;
+       case 1:         return be32dec(buf);
+       case 2:         return be64dec(buf);
+       default:        panic("fdtbus_get_cells: bad cells val %d\n", cells);
+       }
+}
+
+static uint64_t
+fdtbus_decode_range(int phandle, uint64_t paddr)
+{
+       const int parent = OF_parent(phandle);
+       if (parent == -1)
+               return paddr;
+       const uint8_t *buf;
+       int len;
+
+       buf = fdt_getprop(fdtbus_get_data(),
+           fdtbus_phandle2offset(phandle), "ranges", &len);
+       if (buf == NULL)
+               return paddr;
+
+       if (len == 0) {
+               /* pass through to parent */
+               return fdtbus_decode_range(parent, paddr);
+       }
+
+       const int addr_cells = fdtbus_get_addr_cells(phandle);
+       const int size_cells = fdtbus_get_size_cells(phandle);
+       const int paddr_cells = fdtbus_get_addr_cells(OF_parent(parent));
+       if (addr_cells == -1 || size_cells == -1 || paddr_cells == -1)
+               return paddr;
+
+       while (len > 0) {
+               uint64_t cba, pba, cl;
+               cba = fdtbus_get_cells(buf, addr_cells);
+               buf += addr_cells * 4;
+               pba = fdtbus_get_cells(buf, paddr_cells);
+               buf += paddr_cells * 4;
+               cl = fdtbus_get_cells(buf, size_cells);
+               buf += size_cells * 4;
+
+               if (paddr >= cba && paddr < cba + cl)
+                       return fdtbus_decode_range(parent, pba) + (paddr - cba);
+
+               len -= (addr_cells + paddr_cells + size_cells) * 4;
+       }
+
+       /* No mapping found */
+       return paddr;
+}
+
 int
 fdtbus_get_reg(int phandle, u_int index, bus_addr_t *paddr, bus_size_t *psize)
 {
@@ -187,8 +234,8 @@
        const uint8_t *buf;
        int len;
 
-       const int addr_cells = fdtbus_get_addr_cells(phandle);
-       const int size_cells = fdtbus_get_size_cells(phandle);
+       const int addr_cells = fdtbus_get_addr_cells(OF_parent(phandle));
+       const int size_cells = fdtbus_get_size_cells(OF_parent(phandle));
        if (addr_cells == -1 || size_cells == -1)
                return EINVAL;
 
@@ -204,36 +251,18 @@
        if (index >= len / reglen)
                return ENXIO;
 
-       switch (addr_cells) {
-       case 0:
-               addr = 0;
-               break;
-       case 1:
-               addr = be32dec(&buf[index * reglen + 0]);
-               break;
-       case 2:
-               addr = be64dec(&buf[index * reglen + 0]);
-               break;
-       default:
-               panic("fdtbus_get_reg: unsupported addr_cells %d", addr_cells);
-       }
+       buf += index * reglen;
+       addr = fdtbus_get_cells(buf, addr_cells);
+       buf += addr_cells * 4;
+       size = fdtbus_get_cells(buf, size_cells);
 
-       switch (size_cells) {
-       case 0:
-               size = 0;
-               break;
-       case 1:
-               size = be32dec(&buf[index * reglen + addr_cells * 4]);
-               break;
-       case 2:
-               size = be64dec(&buf[index * reglen + addr_cells * 4]);
-               break;
-       default:
-               panic("fdtbus_get_reg: unsupported size_cells %d", size_cells);
+       if (paddr) {
+               *paddr = fdtbus_decode_range(OF_parent(phandle), addr);
+               const char *name = fdt_get_name(fdtbus_get_data(),
+                   fdtbus_phandle2offset(phandle), NULL);
+               aprint_debug("fdt: [%s] decoded addr #%u: %llx -> %llx\n",
+                   name, index, addr, *paddr);
        }
-
-       if (paddr)
-               *paddr = addr;
        if (psize)
                *psize = size;