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Subject[PATCH] x86: OLPC: add OLPC device-tree support (v3)

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.

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: Andres Salomon <dilinger@queued.net>
---
arch/x86/Kconfig | 6 ++
arch/x86/include/asm/olpc_ofw.h | 9 ++
arch/x86/include/asm/prom.h | 1 +
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/olpc_dt.c | 165 +++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/olpc_ofw.c | 5 +
arch/x86/mm/init_32.c | 2 +
7 files changed, 189 insertions(+), 0 deletions(-)
create mode 100644 arch/x86/include/asm/prom.h
create mode 100644 arch/x86/kernel/olpc_dt.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cea0cd9..1d57e2b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2069,11 +2069,17 @@ config OLPC_OPENFIRMWARE
bool "Support for OLPC's Open Firmware"
depends on !X86_64 && !X86_PAE
default y if OLPC
+ 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 K8_NB
diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
index 08fde47..a41250e 100644
--- a/arch/x86/include/asm/olpc_ofw.h
+++ b/arch/x86/include/asm/olpc_ofw.h
@@ -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)
@@ -23,9 +25,16 @@ extern void setup_olpc_ofw_pgd(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) { }

#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 */
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
new file mode 100644
index 0000000..b4ec95f
--- /dev/null
+++ b/arch/x86/include/asm/prom.h
@@ -0,0 +1 @@
+/* dummy prom.h; here to make linux/of.h's #includes happy */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index fedf32a..519539a 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -107,6 +107,7 @@ scx200-y += scx200_32.o

obj-$(CONFIG_OLPC) += olpc.o
obj-$(CONFIG_OLPC_OPENFIRMWARE) += olpc_ofw.o
+obj-$(CONFIG_OLPC_OPENFIRMWARE_DT) += olpc_dt.o
obj-$(CONFIG_X86_MRST) += mrst.o

microcode-y := microcode_core.o
diff --git a/arch/x86/kernel/olpc_dt.c b/arch/x86/kernel/olpc_dt.c
new file mode 100644
index 0000000..f660a11
--- /dev/null
+++ b/arch/x86/kernel/olpc_dt.c
@@ -0,0 +1,165 @@
+/*
+ * olpc_dt.c: 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 (node == -1)
+ return 0;
+
+ if (olpc_ofw("peer", args, res) || node == -1)
+ return 0;
+
+ return node;
+}
+
+static phandle __init olpc_dt_getchild(phandle node)
+{
+ const void *args[] = { (void *)node };
+ void *res[] = { &node };
+
+ if (node == -1)
+ return 0;
+
+ if (olpc_ofw("child", args, res) || 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 (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 (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 (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 < 0) {
+ 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);
+}
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
index 3218aa7..2176048 100644
--- a/arch/x86/kernel/olpc_ofw.c
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -104,3 +104,8 @@ 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;
+}
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index bca7909..41bf85f 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -44,6 +44,7 @@
#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>
@@ -833,6 +834,7 @@ void __init paging_init(void)
/*
* NOTE: at this point the bootmem allocator is fully available.
*/
+ olpc_dt_build_devicetree();
sparse_init();
zone_sizes_init();
}
--
1.5.6.5


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