in irq.c [113:316]
int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
{
struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
__be32 initial_match_array[MAX_PHANDLE_ARGS];
const __be32 *match_array = initial_match_array;
const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
int imaplen, match, i, rc = -EINVAL;
#ifdef DEBUG
of_print_phandle_args("of_irq_parse_raw: ", out_irq);
#endif
ipar = of_node_get(out_irq->np);
/* First get the #interrupt-cells property of the current cursor
* that tells us how to interpret the passed-in intspec. If there
* is none, we are nice and just walk up the tree
*/
do {
if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
break;
tnode = ipar;
ipar = of_irq_find_parent(ipar);
of_node_put(tnode);
} while (ipar);
if (ipar == NULL) {
pr_debug(" -> no parent found !\n");
goto fail;
}
pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
if (out_irq->args_count != intsize)
goto fail;
/* Look for this #address-cells. We have to implement the old linux
* trick of looking for the parent here as some device-trees rely on it
*/
old = of_node_get(ipar);
do {
tmp = of_get_property(old, "#address-cells", NULL);
tnode = of_get_parent(old);
of_node_put(old);
old = tnode;
} while (old && tmp == NULL);
of_node_put(old);
old = NULL;
addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
pr_debug(" -> addrsize=%d\n", addrsize);
/* Range check so that the temporary buffer doesn't overflow */
if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
rc = -EFAULT;
goto fail;
}
/* Precalculate the match array - this simplifies match loop */
for (i = 0; i < addrsize; i++)
initial_match_array[i] = addr ? addr[i] : 0;
for (i = 0; i < intsize; i++)
initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
/* Now start the actual "proper" walk of the interrupt tree */
while (ipar != NULL) {
/*
* Now check if cursor is an interrupt-controller and
* if it is then we are done, unless there is an
* interrupt-map which takes precedence except on one
* of these broken platforms that want to parse
* interrupt-map themselves for $reason.
*/
bool intc = of_property_read_bool(ipar, "interrupt-controller");
imap = of_get_property(ipar, "interrupt-map", &imaplen);
if (intc &&
(!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
pr_debug(" -> got it !\n");
return 0;
}
/*
* interrupt-map parsing does not work without a reg
* property when #address-cells != 0
*/
if (addrsize && !addr) {
pr_debug(" -> no reg passed in when needed !\n");
goto fail;
}
/* No interrupt map, check for an interrupt parent */
if (imap == NULL) {
pr_debug(" -> no map, getting parent\n");
newpar = of_irq_find_parent(ipar);
goto skiplevel;
}
imaplen /= sizeof(u32);
/* Look for a mask */
imask = of_get_property(ipar, "interrupt-map-mask", NULL);
if (!imask)
imask = dummy_imask;
/* Parse interrupt-map */
match = 0;
while (imaplen > (addrsize + intsize + 1) && !match) {
/* Compare specifiers */
match = 1;
for (i = 0; i < (addrsize + intsize); i++, imaplen--)
match &= !((match_array[i] ^ *imap++) & imask[i]);
pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
/* Get the interrupt parent */
if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
newpar = of_node_get(of_irq_dflt_pic);
else
newpar = of_find_node_by_phandle(be32_to_cpup(imap));
imap++;
--imaplen;
/* Check if not found */
if (newpar == NULL) {
pr_debug(" -> imap parent not found !\n");
goto fail;
}
if (!of_device_is_available(newpar))
match = 0;
/* Get #interrupt-cells and #address-cells of new
* parent
*/
if (of_property_read_u32(newpar, "#interrupt-cells",
&newintsize)) {
pr_debug(" -> parent lacks #interrupt-cells!\n");
goto fail;
}
if (of_property_read_u32(newpar, "#address-cells",
&newaddrsize))
newaddrsize = 0;
pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
newintsize, newaddrsize);
/* Check for malformed properties */
if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
|| (imaplen < (newaddrsize + newintsize))) {
rc = -EFAULT;
goto fail;
}
imap += newaddrsize + newintsize;
imaplen -= newaddrsize + newintsize;
pr_debug(" -> imaplen=%d\n", imaplen);
}
if (!match) {
if (intc) {
/*
* The PASEMI Nemo is a known offender, so
* let's only warn for anyone else.
*/
WARN(!IS_ENABLED(CONFIG_PPC_PASEMI),
"%pOF interrupt-map failed, using interrupt-controller\n",
ipar);
return 0;
}
goto fail;
}
/*
* Successfully parsed an interrrupt-map translation; copy new
* interrupt specifier into the out_irq structure
*/
match_array = imap - newaddrsize - newintsize;
for (i = 0; i < newintsize; i++)
out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
out_irq->args_count = intsize = newintsize;
addrsize = newaddrsize;
if (ipar == newpar) {
pr_debug("%pOF interrupt-map entry to self\n", ipar);
return 0;
}
skiplevel:
/* Iterate again with new parent */
out_irq->np = newpar;
pr_debug(" -> new parent: %pOF\n", newpar);
of_node_put(ipar);
ipar = newpar;
newpar = NULL;
}
rc = -ENOENT; /* No interrupt-map found */
fail:
of_node_put(ipar);
of_node_put(newpar);
return rc;
}