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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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