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-rw-r--r--arch/x86/platform/olpc/olpc_dt.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
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+++ b/arch/x86/platform/olpc/olpc_dt.c
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+/*
+ * 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)
+{
+ static u8 *mem;
+ static size_t free_mem;
+ void *res;
+
+ if (free_mem < size) {
+ const size_t chunk_size = max(PAGE_SIZE, size);
+
+ /*
+ * To mimimize the number of allocations, grab at least
+ * PAGE_SIZE of memory (that's an arbitrary choice that's
+ * fast enough on the platforms we care about while minimizing
+ * wasted bootmem) and hand off chunks of it to callers.
+ */
+ res = alloc_bootmem(chunk_size);
+ if (!res)
+ return NULL;
+ prom_early_allocated += chunk_size;
+ memset(res, 0, chunk_size);
+ free_mem = chunk_size;
+ mem = res;
+ }
+
+ /* allocate from the local cache */
+ free_mem -= size;
+ res = mem;
+ mem += 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);
+}