Commit c10d1e26 authored by Andres Salomon's avatar Andres Salomon Committed by H. Peter Anvin

x86, olpc: Add OLPC device-tree support

Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
call into OLPC's Open Firmware to build the tree.

v5: fix buglet with root node check (introduced in v4)

v4: address some minor style issues pointed out by Grant, and explicitly cast
    negative phandle checks to s32.

v3: rename olpc_prom to olpc_dt
  - rework Kconfig entries
  - drop devtree build hook from proc, instead adding a call to x86's
    paging_init (similarly to how sparc64 does it)
  - switch allocation from using slab to alloc_bootmem.  this allows
    the DT to be built earlier during boot (during setup_arch); the
    downside is that there are some 1200 bootmem reservations that are
    done during boot.  Not ideal..
  - add a helper olpc_ofw_is_installed function to test for the
    existence and successful detection of OLPC's OFW.
Signed-off-by: default avatarAndres Salomon <dilinger@queued.net>
LKML-Reference: <20101116220952.26526a80@queued.net>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 4722d194
......@@ -2049,11 +2049,17 @@ config OLPC_OPENFIRMWARE
bool "Support for OLPC's Open Firmware"
depends on !X86_64 && !X86_PAE
default n
select OF
help
This option adds support for the implementation of Open Firmware
that is used on the OLPC XO-1 Children's Machine.
If unsure, say N here.
config OLPC_OPENFIRMWARE_DT
bool
default y if OLPC_OPENFIRMWARE && PROC_DEVICETREE
select OF_PROMTREE
endif # X86_32
config AMD_NB
......
......@@ -8,6 +8,8 @@
#ifdef CONFIG_OLPC_OPENFIRMWARE
extern bool olpc_ofw_is_installed(void);
/* run an OFW command by calling into the firmware */
#define olpc_ofw(name, args, res) \
__olpc_ofw((name), ARRAY_SIZE(args), args, ARRAY_SIZE(res), res)
......@@ -26,10 +28,17 @@ extern bool olpc_ofw_present(void);
#else /* !CONFIG_OLPC_OPENFIRMWARE */
static inline bool olpc_ofw_is_installed(void) { return false; }
static inline void olpc_ofw_detect(void) { }
static inline void setup_olpc_ofw_pgd(void) { }
static inline bool olpc_ofw_present(void) { return false; }
#endif /* !CONFIG_OLPC_OPENFIRMWARE */
#ifdef CONFIG_OLPC_OPENFIRMWARE_DT
extern void olpc_dt_build_devicetree(void);
#else
static inline void olpc_dt_build_devicetree(void) { }
#endif /* CONFIG_OLPC_OPENFIRMWARE_DT */
#endif /* _ASM_X86_OLPC_OFW_H */
/* dummy prom.h; here to make linux/of.h's #includes happy */
......@@ -45,6 +45,7 @@
#include <asm/bugs.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/olpc_ofw.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/paravirt.h>
......@@ -715,6 +716,7 @@ void __init paging_init(void)
/*
* NOTE: at this point the bootmem allocator is fully available.
*/
olpc_dt_build_devicetree();
sparse_init();
zone_sizes_init();
}
......
obj-$(CONFIG_OLPC) += olpc.o
obj-$(CONFIG_OLPC_XO1) += olpc-xo1.o
obj-$(CONFIG_OLPC_OPENFIRMWARE) += olpc_ofw.o
obj-$(CONFIG_OLPC_OPENFIRMWARE_DT) += olpc_dt.o
/*
* OLPC-specific OFW device tree support code.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
* {engebret|bergner}@us.ibm.com
*
* Adapted for sparc by David S. Miller davem@davemloft.net
* Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/bootmem.h>
#include <linux/of.h>
#include <linux/of_pdt.h>
#include <asm/olpc_ofw.h>
static phandle __init olpc_dt_getsibling(phandle node)
{
const void *args[] = { (void *)node };
void *res[] = { &node };
if ((s32)node == -1)
return 0;
if (olpc_ofw("peer", args, res) || (s32)node == -1)
return 0;
return node;
}
static phandle __init olpc_dt_getchild(phandle node)
{
const void *args[] = { (void *)node };
void *res[] = { &node };
if ((s32)node == -1)
return 0;
if (olpc_ofw("child", args, res) || (s32)node == -1) {
pr_err("PROM: %s: fetching child failed!\n", __func__);
return 0;
}
return node;
}
static int __init olpc_dt_getproplen(phandle node, const char *prop)
{
const void *args[] = { (void *)node, prop };
int len;
void *res[] = { &len };
if ((s32)node == -1)
return -1;
if (olpc_ofw("getproplen", args, res)) {
pr_err("PROM: %s: getproplen failed!\n", __func__);
return -1;
}
return len;
}
static int __init olpc_dt_getproperty(phandle node, const char *prop,
char *buf, int bufsize)
{
int plen;
plen = olpc_dt_getproplen(node, prop);
if (plen > bufsize || plen < 1) {
return -1;
} else {
const void *args[] = { (void *)node, prop, buf, (void *)plen };
void *res[] = { &plen };
if (olpc_ofw("getprop", args, res)) {
pr_err("PROM: %s: getprop failed!\n", __func__);
return -1;
}
}
return plen;
}
static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf)
{
const void *args[] = { (void *)node, prev, buf };
int success;
void *res[] = { &success };
buf[0] = '\0';
if ((s32)node == -1)
return -1;
if (olpc_ofw("nextprop", args, res) || success != 1)
return -1;
return 0;
}
static int __init olpc_dt_pkg2path(phandle node, char *buf,
const int buflen, int *len)
{
const void *args[] = { (void *)node, buf, (void *)buflen };
void *res[] = { len };
if ((s32)node == -1)
return -1;
if (olpc_ofw("package-to-path", args, res) || *len < 1)
return -1;
return 0;
}
static unsigned int prom_early_allocated __initdata;
void * __init prom_early_alloc(unsigned long size)
{
void *res;
res = alloc_bootmem(size);
if (res)
memset(res, 0, size);
prom_early_allocated += size;
return res;
}
static struct of_pdt_ops prom_olpc_ops __initdata = {
.nextprop = olpc_dt_nextprop,
.getproplen = olpc_dt_getproplen,
.getproperty = olpc_dt_getproperty,
.getchild = olpc_dt_getchild,
.getsibling = olpc_dt_getsibling,
.pkg2path = olpc_dt_pkg2path,
};
void __init olpc_dt_build_devicetree(void)
{
phandle root;
if (!olpc_ofw_is_installed())
return;
root = olpc_dt_getsibling(0);
if (!root) {
pr_err("PROM: unable to get root node from OFW!\n");
return;
}
of_pdt_build_devicetree(root, &prom_olpc_ops);
pr_info("PROM DT: Built device tree with %u bytes of memory.\n",
prom_early_allocated);
}
......@@ -110,3 +110,8 @@ void __init olpc_ofw_detect(void)
(unsigned long)olpc_ofw_cif, (-start) >> 20);
reserve_top_address(-start);
}
bool __init olpc_ofw_is_installed(void)
{
return olpc_ofw_cif != NULL;
}
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