linux/arch/sparc/prom/tree_64.c
David S. Miller 25edd6946a sparc64: Get rid of indirect p1275 PROM call buffer.
This is based upon a report by Meelis Roos showing that it's possible
that we'll try to fetch a property that is 32K in size with some
devices.  With the current fixed 3K buffer we use for moving data in
and out of the firmware during PROM calls, that simply won't work.

In fact, it will scramble random kernel data during bootup.

The reasoning behind the temporary buffer is entirely historical.  It
used to be the case that we had problems referencing dynamic kernel
memory (including the stack) early in the boot process before we
explicitly told the firwmare to switch us over to the kernel trap
table.

So what we did was always give the firmware buffers that were locked
into the main kernel image.

But we no longer have problems like that, so get rid of all of this
indirect bounce buffering.

Besides fixing Meelis's bug, this also makes the kernel data about 3K
smaller.

It was also discovered during these conversions that the
implementation of prom_retain() was completely wrong, so that was
fixed here as well.  Currently that interface is not in use.

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-23 23:10:57 -07:00

410 lines
8.1 KiB
C

/*
* tree.c: Basic device tree traversal/scanning for the Linux
* prom library.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/string.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/ldc.h>
static int prom_node_to_node(const char *type, int node)
{
unsigned long args[5];
args[0] = (unsigned long) type;
args[1] = 1;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[4];
}
/* Return the child of node 'node' or zero if no this node has no
* direct descendent.
*/
inline int __prom_getchild(int node)
{
return prom_node_to_node("child", node);
}
inline int prom_getchild(int node)
{
int cnode;
if (node == -1)
return 0;
cnode = __prom_getchild(node);
if (cnode == -1)
return 0;
return cnode;
}
EXPORT_SYMBOL(prom_getchild);
inline int prom_getparent(int node)
{
int cnode;
if (node == -1)
return 0;
cnode = prom_node_to_node("parent", node);
if (cnode == -1)
return 0;
return cnode;
}
/* Return the next sibling of node 'node' or zero if no more siblings
* at this level of depth in the tree.
*/
inline int __prom_getsibling(int node)
{
return prom_node_to_node(prom_peer_name, node);
}
inline int prom_getsibling(int node)
{
int sibnode;
if (node == -1)
return 0;
sibnode = __prom_getsibling(node);
if (sibnode == -1)
return 0;
return sibnode;
}
EXPORT_SYMBOL(prom_getsibling);
/* Return the length in bytes of property 'prop' at node 'node'.
* Return -1 on error.
*/
inline int prom_getproplen(int node, const char *prop)
{
unsigned long args[6];
if (!node || !prop)
return -1;
args[0] = (unsigned long) "getproplen";
args[1] = 2;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = (unsigned long) prop;
args[5] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[5];
}
EXPORT_SYMBOL(prom_getproplen);
/* Acquire a property 'prop' at node 'node' and place it in
* 'buffer' which has a size of 'bufsize'. If the acquisition
* was successful the length will be returned, else -1 is returned.
*/
inline int prom_getproperty(int node, const char *prop,
char *buffer, int bufsize)
{
unsigned long args[8];
int plen;
plen = prom_getproplen(node, prop);
if ((plen > bufsize) || (plen == 0) || (plen == -1))
return -1;
args[0] = (unsigned long) prom_getprop_name;
args[1] = 4;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = (unsigned long) prop;
args[5] = (unsigned long) buffer;
args[6] = bufsize;
args[7] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[7];
}
EXPORT_SYMBOL(prom_getproperty);
/* Acquire an integer property and return its value. Returns -1
* on failure.
*/
inline int prom_getint(int node, const char *prop)
{
int intprop;
if (prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
return intprop;
return -1;
}
EXPORT_SYMBOL(prom_getint);
/* Acquire an integer property, upon error return the passed default
* integer.
*/
int prom_getintdefault(int node, const char *property, int deflt)
{
int retval;
retval = prom_getint(node, property);
if (retval == -1)
return deflt;
return retval;
}
EXPORT_SYMBOL(prom_getintdefault);
/* Acquire a boolean property, 1=TRUE 0=FALSE. */
int prom_getbool(int node, const char *prop)
{
int retval;
retval = prom_getproplen(node, prop);
if (retval == -1)
return 0;
return 1;
}
EXPORT_SYMBOL(prom_getbool);
/* Acquire a property whose value is a string, returns a null
* string on error. The char pointer is the user supplied string
* buffer.
*/
void prom_getstring(int node, const char *prop, char *user_buf, int ubuf_size)
{
int len;
len = prom_getproperty(node, prop, user_buf, ubuf_size);
if (len != -1)
return;
user_buf[0] = 0;
}
EXPORT_SYMBOL(prom_getstring);
/* Does the device at node 'node' have name 'name'?
* YES = 1 NO = 0
*/
int prom_nodematch(int node, const char *name)
{
char namebuf[128];
prom_getproperty(node, "name", namebuf, sizeof(namebuf));
if (strcmp(namebuf, name) == 0)
return 1;
return 0;
}
/* Search siblings at 'node_start' for a node with name
* 'nodename'. Return node if successful, zero if not.
*/
int prom_searchsiblings(int node_start, const char *nodename)
{
int thisnode, error;
char promlib_buf[128];
for(thisnode = node_start; thisnode;
thisnode=prom_getsibling(thisnode)) {
error = prom_getproperty(thisnode, "name", promlib_buf,
sizeof(promlib_buf));
/* Should this ever happen? */
if(error == -1) continue;
if(strcmp(nodename, promlib_buf)==0) return thisnode;
}
return 0;
}
EXPORT_SYMBOL(prom_searchsiblings);
static const char *prom_nextprop_name = "nextprop";
/* Return the first property type for node 'node'.
* buffer should be at least 32B in length
*/
inline char *prom_firstprop(int node, char *buffer)
{
unsigned long args[7];
*buffer = 0;
if (node == -1)
return buffer;
args[0] = (unsigned long) prom_nextprop_name;
args[1] = 3;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = 0;
args[5] = (unsigned long) buffer;
args[6] = (unsigned long) -1;
p1275_cmd_direct(args);
return buffer;
}
EXPORT_SYMBOL(prom_firstprop);
/* Return the property type string after property type 'oprop'
* at node 'node' . Returns NULL string if no more
* property types for this node.
*/
inline char *prom_nextprop(int node, const char *oprop, char *buffer)
{
unsigned long args[7];
char buf[32];
if (node == -1) {
*buffer = 0;
return buffer;
}
if (oprop == buffer) {
strcpy (buf, oprop);
oprop = buf;
}
args[0] = (unsigned long) prom_nextprop_name;
args[1] = 3;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = (unsigned long) oprop;
args[5] = (unsigned long) buffer;
args[6] = (unsigned long) -1;
p1275_cmd_direct(args);
return buffer;
}
EXPORT_SYMBOL(prom_nextprop);
int
prom_finddevice(const char *name)
{
unsigned long args[5];
if (!name)
return 0;
args[0] = (unsigned long) "finddevice";
args[1] = 1;
args[2] = 1;
args[3] = (unsigned long) name;
args[4] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[4];
}
EXPORT_SYMBOL(prom_finddevice);
int prom_node_has_property(int node, const char *prop)
{
char buf [32];
*buf = 0;
do {
prom_nextprop(node, buf, buf);
if (!strcmp(buf, prop))
return 1;
} while (*buf);
return 0;
}
EXPORT_SYMBOL(prom_node_has_property);
/* Set property 'pname' at node 'node' to value 'value' which has a length
* of 'size' bytes. Return the number of bytes the prom accepted.
*/
int
prom_setprop(int node, const char *pname, char *value, int size)
{
unsigned long args[8];
if (size == 0)
return 0;
if ((pname == 0) || (value == 0))
return 0;
#ifdef CONFIG_SUN_LDOMS
if (ldom_domaining_enabled) {
ldom_set_var(pname, value);
return 0;
}
#endif
args[0] = (unsigned long) "setprop";
args[1] = 4;
args[2] = 1;
args[3] = (unsigned int) node;
args[4] = (unsigned long) pname;
args[5] = (unsigned long) value;
args[6] = size;
args[7] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[7];
}
EXPORT_SYMBOL(prom_setprop);
inline int prom_inst2pkg(int inst)
{
unsigned long args[5];
int node;
args[0] = (unsigned long) "instance-to-package";
args[1] = 1;
args[2] = 1;
args[3] = (unsigned int) inst;
args[4] = (unsigned long) -1;
p1275_cmd_direct(args);
node = (int) args[4];
if (node == -1)
return 0;
return node;
}
/* Return 'node' assigned to a particular prom 'path'
* FIXME: Should work for v0 as well
*/
int
prom_pathtoinode(const char *path)
{
int node, inst;
inst = prom_devopen (path);
if (inst == 0)
return 0;
node = prom_inst2pkg(inst);
prom_devclose(inst);
if (node == -1)
return 0;
return node;
}
int prom_ihandle2path(int handle, char *buffer, int bufsize)
{
unsigned long args[7];
args[0] = (unsigned long) "instance-to-path";
args[1] = 3;
args[2] = 1;
args[3] = (unsigned int) handle;
args[4] = (unsigned long) buffer;
args[5] = bufsize;
args[6] = (unsigned long) -1;
p1275_cmd_direct(args);
return (int) args[6];
}