Commit a0342c08 authored by Kumar Gala's avatar Kumar Gala
Browse files

fdt: Add fdt_translate_address to convert reg node to cpu phys addr



This code is extracted out of the Linux Kernel code from
arch/powerpc/kernel/prom_parse.c.

We maintain some of the same structure to support multiple bus types even
though we only have one in the current code.  In the future we might want
to translate across a PCI bus and thus it will be easier to add that
functionality back in.
Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
Acked-by: default avatarGerald Van Baren <vanbaren@cideas.com>
parent 46f3e385
......@@ -2,6 +2,8 @@
* (C) Copyright 2007
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
*
* Copyright 2010 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
......@@ -861,3 +863,265 @@ void fdt_del_node_and_alias(void *blob, const char *alias)
off = fdt_path_offset(blob, "/aliases");
fdt_delprop(blob, off, alias);
}
/* Helper to read a big number; size is in cells (not bytes) */
static inline u64 of_read_number(const __be32 *cell, int size)
{
u64 r = 0;
while (size--)
r = (r << 32) | be32_to_cpu(*(cell++));
return r;
}
static int of_n_cells(const void *blob, int nodeoffset, const char *name)
{
int np;
const int *ip;
do {
np = fdt_parent_offset(blob, nodeoffset);
if (np >= 0)
nodeoffset = np;
ip = (int *)fdt_getprop(blob, nodeoffset, name, NULL);
if (ip)
return be32_to_cpup(ip);
} while (np >= 0);
/* No #<NAME>-cells property for the root node */
return 1;
}
int of_n_addr_cells(const void *blob, int nodeoffset)
{
return of_n_cells(blob, nodeoffset, "#address-cells");
}
int of_n_size_cells(const void *blob, int nodeoffset)
{
return of_n_cells(blob, nodeoffset, "#size-cells");
}
#define PRu64 "%llx"
/* Max address size we deal with */
#define OF_MAX_ADDR_CELLS 4
#define OF_BAD_ADDR ((u64)-1)
#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \
(ns) > 0)
/* Debug utility */
#ifdef DEBUG
static void of_dump_addr(const char *s, const u32 *addr, int na)
{
printf("%s", s);
while(na--)
printf(" %08x", *(addr++));
printf("\n");
}
#else
static void of_dump_addr(const char *s, const u32 *addr, int na) { }
#endif
/* Callbacks for bus specific translators */
struct of_bus {
const char *name;
const char *addresses;
void (*count_cells)(void *blob, int offset,
int *addrc, int *sizec);
u64 (*map)(u32 *addr, const u32 *range,
int na, int ns, int pna);
int (*translate)(u32 *addr, u64 offset, int na);
};
/* Default translator (generic bus) */
static void of_bus_default_count_cells(void *blob, int offset,
int *addrc, int *sizec)
{
if (addrc)
*addrc = of_n_addr_cells(blob, offset);
if (sizec)
*sizec = of_n_size_cells(blob, offset);
}
static u64 of_bus_default_map(u32 *addr, const u32 *range,
int na, int ns, int pna)
{
u64 cp, s, da;
cp = of_read_number(range, na);
s = of_read_number(range + na + pna, ns);
da = of_read_number(addr, na);
debug("OF: default map, cp="PRu64", s="PRu64", da="PRu64"\n",
cp, s, da);
if (da < cp || da >= (cp + s))
return OF_BAD_ADDR;
return da - cp;
}
static int of_bus_default_translate(u32 *addr, u64 offset, int na)
{
u64 a = of_read_number(addr, na);
memset(addr, 0, na * 4);
a += offset;
if (na > 1)
addr[na - 2] = a >> 32;
addr[na - 1] = a & 0xffffffffu;
return 0;
}
/* Array of bus specific translators */
static struct of_bus of_busses[] = {
/* Default */
{
.name = "default",
.addresses = "reg",
.count_cells = of_bus_default_count_cells,
.map = of_bus_default_map,
.translate = of_bus_default_translate,
},
};
static int of_translate_one(void * blob, int parent, struct of_bus *bus,
struct of_bus *pbus, u32 *addr,
int na, int ns, int pna, const char *rprop)
{
const u32 *ranges;
int rlen;
int rone;
u64 offset = OF_BAD_ADDR;
/* Normally, an absence of a "ranges" property means we are
* crossing a non-translatable boundary, and thus the addresses
* below the current not cannot be converted to CPU physical ones.
* Unfortunately, while this is very clear in the spec, it's not
* what Apple understood, and they do have things like /uni-n or
* /ht nodes with no "ranges" property and a lot of perfectly
* useable mapped devices below them. Thus we treat the absence of
* "ranges" as equivalent to an empty "ranges" property which means
* a 1:1 translation at that level. It's up to the caller not to try
* to translate addresses that aren't supposed to be translated in
* the first place. --BenH.
*/
ranges = (u32 *)fdt_getprop(blob, parent, rprop, &rlen);
if (ranges == NULL || rlen == 0) {
offset = of_read_number(addr, na);
memset(addr, 0, pna * 4);
debug("OF: no ranges, 1:1 translation\n");
goto finish;
}
debug("OF: walking ranges...\n");
/* Now walk through the ranges */
rlen /= 4;
rone = na + pna + ns;
for (; rlen >= rone; rlen -= rone, ranges += rone) {
offset = bus->map(addr, ranges, na, ns, pna);
if (offset != OF_BAD_ADDR)
break;
}
if (offset == OF_BAD_ADDR) {
debug("OF: not found !\n");
return 1;
}
memcpy(addr, ranges + na, 4 * pna);
finish:
of_dump_addr("OF: parent translation for:", addr, pna);
debug("OF: with offset: "PRu64"\n", offset);
/* Translate it into parent bus space */
return pbus->translate(addr, offset, pna);
}
/*
* Translate an address from the device-tree into a CPU physical address,
* this walks up the tree and applies the various bus mappings on the
* way.
*
* Note: We consider that crossing any level with #size-cells == 0 to mean
* that translation is impossible (that is we are not dealing with a value
* that can be mapped to a cpu physical address). This is not really specified
* that way, but this is traditionally the way IBM at least do things
*/
u64 __of_translate_address(void *blob, int node_offset, const u32 *in_addr,
const char *rprop)
{
int parent;
struct of_bus *bus, *pbus;
u32 addr[OF_MAX_ADDR_CELLS];
int na, ns, pna, pns;
u64 result = OF_BAD_ADDR;
debug("OF: ** translation for device %s **\n",
fdt_get_name(blob, node_offset, NULL));
/* Get parent & match bus type */
parent = fdt_parent_offset(blob, node_offset);
if (parent < 0)
goto bail;
bus = &of_busses[0];
/* Cound address cells & copy address locally */
bus->count_cells(blob, node_offset, &na, &ns);
if (!OF_CHECK_COUNTS(na, ns)) {
printf("%s: Bad cell count for %s\n", __FUNCTION__,
fdt_get_name(blob, node_offset, NULL));
goto bail;
}
memcpy(addr, in_addr, na * 4);
debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
bus->name, na, ns, fdt_get_name(blob, parent, NULL));
of_dump_addr("OF: translating address:", addr, na);
/* Translate */
for (;;) {
/* Switch to parent bus */
node_offset = parent;
parent = fdt_parent_offset(blob, node_offset);
/* If root, we have finished */
if (parent < 0) {
debug("OF: reached root node\n");
result = of_read_number(addr, na);
break;
}
/* Get new parent bus and counts */
pbus = &of_busses[0];
pbus->count_cells(blob, node_offset, &pna, &pns);
if (!OF_CHECK_COUNTS(pna, pns)) {
printf("%s: Bad cell count for %s\n", __FUNCTION__,
fdt_get_name(blob, node_offset, NULL));
break;
}
debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
pbus->name, pna, pns, fdt_get_name(blob, parent, NULL));
/* Apply bus translation */
if (of_translate_one(blob, node_offset, bus, pbus,
addr, na, ns, pna, rprop))
break;
/* Complete the move up one level */
na = pna;
ns = pns;
bus = pbus;
of_dump_addr("OF: one level translation:", addr, na);
}
bail:
return result;
}
u64 fdt_translate_address(void *blob, int node_offset, const u32 *in_addr)
{
return __of_translate_address(blob, node_offset, in_addr, "ranges");
}
......@@ -83,6 +83,7 @@ int fdt_fixup_nor_flash_size(void *blob, int cs, u32 size);
void fdt_fixup_mtdparts(void *fdt, void *node_info, int node_info_size);
void fdt_del_node_and_alias(void *blob, const char *alias);
u64 fdt_translate_address(void *blob, int node_offset, const u32 *in_addr);
#endif /* ifdef CONFIG_OF_LIBFDT */
#endif /* ifndef __FDT_SUPPORT_H */
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment