Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

5 files changed, 750 insertions, 0 deletions

diff --git a/arch/x86/platform/olpc/Makefile b/arch/x86/platform/olpc/Makefile
new file mode 100644
index 000000000000..81c5e2165c24
--- /dev/null
+++ b/arch/x86/platform/olpc/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_OLPC)              += olpc.o olpc_ofw.o olpc_dt.o
+obj-$(CONFIG_OLPC_XO1)          += olpc-xo1.o
diff --git a/arch/x86/platform/olpc/olpc-xo1.c b/arch/x86/platform/olpc/olpc-xo1.c
new file mode 100644
index 000000000000..ab81fb271760
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc-xo1.c
@@ -0,0 +1,146 @@
+/*
+ * Support for features of the OLPC XO-1 laptop
+ *
+ * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
+ * Copyright (C) 2010 One Laptop per Child
+ * Copyright (C) 2006 Red Hat, Inc.
+ * Copyright (C) 2006 Advanced Micro Devices, Inc.
+ *
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/mfd/core.h>
+
+#include <asm/io.h>
+#include <asm/olpc.h>
+
+#define DRV_NAME "olpc-xo1"
+
+/* PMC registers (PMS block) */
+#define PM_SCLK         0x10
+#define PM_IN_SLPCTL    0x20
+#define PM_WKXD         0x34
+#define PM_WKD          0x30
+#define PM_SSC          0x54
+
+/* PM registers (ACPI block) */
+#define PM1_CNT         0x08
+#define PM_GPE0_STS     0x18
+
+static unsigned long acpi_base;
+static unsigned long pms_base;
+
+static void xo1_power_off(void)
+{
+        printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
+
+        /* Enable all of these controls with 0 delay */
+        outl(0x40000000, pms_base + PM_SCLK);
+        outl(0x40000000, pms_base + PM_IN_SLPCTL);
+        outl(0x40000000, pms_base + PM_WKXD);
+        outl(0x40000000, pms_base + PM_WKD);
+
+        /* Clear status bits (possibly unnecessary) */
+        outl(0x0002ffff, pms_base  + PM_SSC);
+        outl(0xffffffff, acpi_base + PM_GPE0_STS);
+
+        /* Write SLP_EN bit to start the machinery */
+        outl(0x00002000, acpi_base + PM1_CNT);
+}
+
+static int __devinit olpc_xo1_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        int err;
+
+        /* don't run on non-XOs */
+        if (!machine_is_olpc())
+                return -ENODEV;
+
+        err = mfd_cell_enable(pdev);
+        if (err)
+                return err;
+
+        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+        if (!res) {
+                dev_err(&pdev->dev, "can't fetch device resource info\n");
+                return -EIO;
+        }
+        if (strcmp(pdev->name, "cs5535-pms") == 0)
+                pms_base = res->start;
+        else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
+                acpi_base = res->start;
+
+        /* If we have both addresses, we can override the poweroff hook */
+        if (pms_base && acpi_base) {
+                pm_power_off = xo1_power_off;
+                printk(KERN_INFO "OLPC XO-1 support registered\n");
+        }
+
+        return 0;
+}
+
+static int __devexit olpc_xo1_remove(struct platform_device *pdev)
+{
+        mfd_cell_disable(pdev);
+
+        if (strcmp(pdev->name, "cs5535-pms") == 0)
+                pms_base = 0;
+        else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
+                acpi_base = 0;
+
+        pm_power_off = NULL;
+        return 0;
+}
+
+static struct platform_driver cs5535_pms_drv = {
+        .driver = {
+                .name = "cs5535-pms",
+                .owner = THIS_MODULE,
+        },
+        .probe = olpc_xo1_probe,
+        .remove = __devexit_p(olpc_xo1_remove),
+};
+
+static struct platform_driver cs5535_acpi_drv = {
+        .driver = {
+                .name = "olpc-xo1-pm-acpi",
+                .owner = THIS_MODULE,
+        },
+        .probe = olpc_xo1_probe,
+        .remove = __devexit_p(olpc_xo1_remove),
+};
+
+static int __init olpc_xo1_init(void)
+{
+        int r;
+
+        r = platform_driver_register(&cs5535_pms_drv);
+        if (r)
+                return r;
+
+        r = platform_driver_register(&cs5535_acpi_drv);
+        if (r)
+                platform_driver_unregister(&cs5535_pms_drv);
+
+        return r;
+}
+
+static void __exit olpc_xo1_exit(void)
+{
+        platform_driver_unregister(&cs5535_acpi_drv);
+        platform_driver_unregister(&cs5535_pms_drv);
+}
+
+MODULE_AUTHOR("Daniel Drake <dsd@laptop.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:cs5535-pms");
+
+module_init(olpc_xo1_init);
+module_exit(olpc_xo1_exit);
diff --git a/arch/x86/platform/olpc/olpc.c b/arch/x86/platform/olpc/olpc.c
new file mode 100644
index 000000000000..0060fd59ea00
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc.c
@@ -0,0 +1,284 @@
+/*
+ * Support for the OLPC DCON and OLPC EC access
+ *
+ * Copyright © 2006  Advanced Micro Devices, Inc.
+ * Copyright © 2007-2008  Andres Salomon <dilinger@debian.org>
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+
+#include <asm/geode.h>
+#include <asm/setup.h>
+#include <asm/olpc.h>
+#include <asm/olpc_ofw.h>
+
+struct olpc_platform_t olpc_platform_info;
+EXPORT_SYMBOL_GPL(olpc_platform_info);
+
+static DEFINE_SPINLOCK(ec_lock);
+
+/* what the timeout *should* be (in ms) */
+#define EC_BASE_TIMEOUT 20
+
+/* the timeout that bugs in the EC might force us to actually use */
+static int ec_timeout = EC_BASE_TIMEOUT;
+
+static int __init olpc_ec_timeout_set(char *str)
+{
+        if (get_option(&str, &ec_timeout) != 1) {
+                ec_timeout = EC_BASE_TIMEOUT;
+                printk(KERN_ERR "olpc-ec:  invalid argument to "
+                                "'olpc_ec_timeout=', ignoring!\n");
+        }
+        printk(KERN_DEBUG "olpc-ec:  using %d ms delay for EC commands.\n",
+                        ec_timeout);
+        return 1;
+}
+__setup("olpc_ec_timeout=", olpc_ec_timeout_set);
+
+/*
+ * These {i,o}bf_status functions return whether the buffers are full or not.
+ */
+
+static inline unsigned int ibf_status(unsigned int port)
+{
+        return !!(inb(port) & 0x02);
+}
+
+static inline unsigned int obf_status(unsigned int port)
+{
+        return inb(port) & 0x01;
+}
+
+#define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
+static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
+{
+        unsigned int timeo;
+        int state = ibf_status(port);
+
+        for (timeo = ec_timeout; state != desired && timeo; timeo--) {
+                mdelay(1);
+                state = ibf_status(port);
+        }
+
+        if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
+                        timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
+                printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for IBF!\n",
+                                line, ec_timeout - timeo);
+        }
+
+        return !(state == desired);
+}
+
+#define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
+static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
+{
+        unsigned int timeo;
+        int state = obf_status(port);
+
+        for (timeo = ec_timeout; state != desired && timeo; timeo--) {
+                mdelay(1);
+                state = obf_status(port);
+        }
+
+        if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
+                        timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
+                printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for OBF!\n",
+                                line, ec_timeout - timeo);
+        }
+
+        return !(state == desired);
+}
+
+/*
+ * This allows the kernel to run Embedded Controller commands.  The EC is
+ * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
+ * available EC commands are here:
+ * <http://wiki.laptop.org/go/Ec_specification>.  Unfortunately, while
+ * OpenFirmware's source is available, the EC's is not.
+ */
+int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
+                unsigned char *outbuf,  size_t outlen)
+{
+        unsigned long flags;
+        int ret = -EIO;
+        int i;
+        int restarts = 0;
+
+        spin_lock_irqsave(&ec_lock, flags);
+
+        /* Clear OBF */
+        for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
+                inb(0x68);
+        if (i == 10) {
+                printk(KERN_ERR "olpc-ec:  timeout while attempting to "
+                                "clear OBF flag!\n");
+                goto err;
+        }
+
+        if (wait_on_ibf(0x6c, 0)) {
+                printk(KERN_ERR "olpc-ec:  timeout waiting for EC to "
+                                "quiesce!\n");
+                goto err;
+        }
+
+restart:
+        /*
+         * Note that if we time out during any IBF checks, that's a failure;
+         * we have to return.  There's no way for the kernel to clear that.
+         *
+         * If we time out during an OBF check, we can restart the command;
+         * reissuing it will clear the OBF flag, and we should be alright.
+         * The OBF flag will sometimes misbehave due to what we believe
+         * is a hardware quirk..
+         */
+        pr_devel("olpc-ec:  running cmd 0x%x\n", cmd);
+        outb(cmd, 0x6c);
+
+        if (wait_on_ibf(0x6c, 0)) {
+                printk(KERN_ERR "olpc-ec:  timeout waiting for EC to read "
+                                "command!\n");
+                goto err;
+        }
+
+        if (inbuf && inlen) {
+                /* write data to EC */
+                for (i = 0; i < inlen; i++) {
+                        if (wait_on_ibf(0x6c, 0)) {
+                                printk(KERN_ERR "olpc-ec:  timeout waiting for"
+                                                " EC accept data!\n");
+                                goto err;
+                        }
+                        pr_devel("olpc-ec:  sending cmd arg 0x%x\n", inbuf[i]);
+                        outb(inbuf[i], 0x68);
+                }
+        }
+        if (outbuf && outlen) {
+                /* read data from EC */
+                for (i = 0; i < outlen; i++) {
+                        if (wait_on_obf(0x6c, 1)) {
+                                printk(KERN_ERR "olpc-ec:  timeout waiting for"
+                                                " EC to provide data!\n");
+                                if (restarts++ < 10)
+                                        goto restart;
+                                goto err;
+                        }
+                        outbuf[i] = inb(0x68);
+                        pr_devel("olpc-ec:  received 0x%x\n", outbuf[i]);
+                }
+        }
+
+        ret = 0;
+err:
+        spin_unlock_irqrestore(&ec_lock, flags);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(olpc_ec_cmd);
+
+static bool __init check_ofw_architecture(struct device_node *root)
+{
+        const char *olpc_arch;
+        int propsize;
+
+        olpc_arch = of_get_property(root, "architecture", &propsize);
+        return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
+}
+
+static u32 __init get_board_revision(struct device_node *root)
+{
+        int propsize;
+        const __be32 *rev;
+
+        rev = of_get_property(root, "board-revision-int", &propsize);
+        if (propsize != 4)
+                return 0;
+
+        return be32_to_cpu(*rev);
+}
+
+static bool __init platform_detect(void)
+{
+        struct device_node *root = of_find_node_by_path("/");
+        bool success;
+
+        if (!root)
+                return false;
+
+        success = check_ofw_architecture(root);
+        if (success) {
+                olpc_platform_info.boardrev = get_board_revision(root);
+                olpc_platform_info.flags |= OLPC_F_PRESENT;
+        }
+
+        of_node_put(root);
+        return success;
+}
+
+static int __init add_xo1_platform_devices(void)
+{
+        struct platform_device *pdev;
+
+        pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0);
+        if (IS_ERR(pdev))
+                return PTR_ERR(pdev);
+
+        pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
+        if (IS_ERR(pdev))
+                return PTR_ERR(pdev);
+
+        return 0;
+}
+
+static int __init olpc_init(void)
+{
+        int r = 0;
+
+        if (!olpc_ofw_present() || !platform_detect())
+                return 0;
+
+        spin_lock_init(&ec_lock);
+
+        /* assume B1 and above models always have a DCON */
+        if (olpc_board_at_least(olpc_board(0xb1)))
+                olpc_platform_info.flags |= OLPC_F_DCON;
+
+        /* get the EC revision */
+        olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
+                        (unsigned char *) &olpc_platform_info.ecver, 1);
+
+#ifdef CONFIG_PCI_OLPC
+        /* If the VSA exists let it emulate PCI, if not emulate in kernel.
+         * XO-1 only. */
+        if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) &&
+                        !cs5535_has_vsa2())
+                x86_init.pci.arch_init = pci_olpc_init;
+#endif
+
+        printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
+                        ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
+                        olpc_platform_info.boardrev >> 4,
+                        olpc_platform_info.ecver);
+
+        if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */
+                r = add_xo1_platform_devices();
+                if (r)
+                        return r;
+        }
+
+        return 0;
+}
+
+postcore_initcall(olpc_init);
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
new file mode 100644
index 000000000000..d39f63d017d2
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc_dt.c
@@ -0,0 +1,201 @@
+/*
+ * 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_platform.h>
+#include <linux/of_pdt.h>
+#include <asm/olpc.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);
+                BUG_ON(!res);
+                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);
+}
+
+/* A list of DT node/bus matches that we want to expose as platform devices */
+static struct of_device_id __initdata of_ids[] = {
+        { .compatible = "olpc,xo1-battery" },
+        { .compatible = "olpc,xo1-dcon" },
+        { .compatible = "olpc,xo1-rtc" },
+        {},
+};
+
+static int __init olpc_create_platform_devices(void)
+{
+        if (machine_is_olpc())
+                return of_platform_bus_probe(NULL, of_ids, NULL);
+        else
+                return 0;
+}
+device_initcall(olpc_create_platform_devices);
diff --git a/arch/x86/platform/olpc/olpc_ofw.c b/arch/x86/platform/olpc/olpc_ofw.c
new file mode 100644
index 000000000000..e7604f62870d
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc_ofw.c
@@ -0,0 +1,117 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <asm/page.h>
+#include <asm/setup.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/olpc_ofw.h>
+
+/* address of OFW callback interface; will be NULL if OFW isn't found */
+static int (*olpc_ofw_cif)(int *);
+
+/* page dir entry containing OFW's pgdir table; filled in by head_32.S */
+u32 olpc_ofw_pgd __initdata;
+
+static DEFINE_SPINLOCK(ofw_lock);
+
+#define MAXARGS 10
+
+void __init setup_olpc_ofw_pgd(void)
+{
+        pgd_t *base, *ofw_pde;
+
+        if (!olpc_ofw_cif)
+                return;
+
+        /* fetch OFW's PDE */
+        base = early_ioremap(olpc_ofw_pgd, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
+        if (!base) {
+                printk(KERN_ERR "failed to remap OFW's pgd - disabling OFW!\n");
+                olpc_ofw_cif = NULL;
+                return;
+        }
+        ofw_pde = &base[OLPC_OFW_PDE_NR];
+
+        /* install OFW's PDE permanently into the kernel's pgtable */
+        set_pgd(&swapper_pg_dir[OLPC_OFW_PDE_NR], *ofw_pde);
+        /* implicit optimization barrier here due to uninline function return */
+
+        early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
+}
+
+int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
+                void **res)
+{
+        int ofw_args[MAXARGS + 3];
+        unsigned long flags;
+        int ret, i, *p;
+
+        BUG_ON(nr_args + nr_res > MAXARGS);
+
+        if (!olpc_ofw_cif)
+                return -EIO;
+
+        ofw_args[0] = (int)name;
+        ofw_args[1] = nr_args;
+        ofw_args[2] = nr_res;
+
+        p = &ofw_args[3];
+        for (i = 0; i < nr_args; i++, p++)
+                *p = (int)args[i];
+
+        /* call into ofw */
+        spin_lock_irqsave(&ofw_lock, flags);
+        ret = olpc_ofw_cif(ofw_args);
+        spin_unlock_irqrestore(&ofw_lock, flags);
+
+        if (!ret) {
+                for (i = 0; i < nr_res; i++, p++)
+                        *((int *)res[i]) = *p;
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(__olpc_ofw);
+
+bool olpc_ofw_present(void)
+{
+        return olpc_ofw_cif != NULL;
+}
+EXPORT_SYMBOL_GPL(olpc_ofw_present);
+
+/* OFW cif _should_ be above this address */
+#define OFW_MIN 0xff000000
+
+/* OFW starts on a 1MB boundary */
+#define OFW_BOUND (1<<20)
+
+void __init olpc_ofw_detect(void)
+{
+        struct olpc_ofw_header *hdr = &boot_params.olpc_ofw_header;
+        unsigned long start;
+
+        /* ensure OFW booted us by checking for "OFW " string */
+        if (hdr->ofw_magic != OLPC_OFW_SIG)
+                return;
+
+        olpc_ofw_cif = (int (*)(int *))hdr->cif_handler;
+
+        if ((unsigned long)olpc_ofw_cif < OFW_MIN) {
+                printk(KERN_ERR "OFW detected, but cif has invalid address 0x%lx - disabling.\n",
+                                (unsigned long)olpc_ofw_cif);
+                olpc_ofw_cif = NULL;
+                return;
+        }
+
+        /* determine where OFW starts in memory */
+        start = round_down((unsigned long)olpc_ofw_cif, OFW_BOUND);
+        printk(KERN_INFO "OFW detected in memory, cif @ 0x%lx (reserving top %ldMB)\n",
+                        (unsigned long)olpc_ofw_cif, (-start) >> 20);
+        reserve_top_address(-start);
+}
+
+bool __init olpc_ofw_is_installed(void)
+{
+        return olpc_ofw_cif != NULL;
+}