9 files changed, 173 insertions, 8 deletions

diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index feb37e177010..cf5437deda81 100644
--- a/Documentation/x86/zero-page.txt
+++ b/Documentation/x86/zero-page.txt
@@ -18,6 +18,7 @@ Offset	Proto	Name		Meaning
 080/010 ALL     hd0_info        hd0 disk parameter, OBSOLETE!!
 090/010 ALL     hd1_info        hd1 disk parameter, OBSOLETE!!
 0A0/010 ALL     sys_desc_table  System description table (struct sys_desc_table)
+0B0/010 ALL     olpc_ofw_header OLPC's OpenFirmware CIF and friends
 140/080 ALL     edid_info       Video mode setup (struct edid_info)
 1C0/020 ALL     efi_info        EFI 32 information (struct efi_info)
 1E0/004 ALL     alk_mem_k       Alternative mem check, in KB
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index dcb0593b4a66..71c194db2e0a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2062,6 +2062,15 @@ config OLPC
           Add support for detecting the unique features of the OLPC
           XO hardware.
 
+config OLPC_OPENFIRMWARE
+        bool "Support for OLPC's Open Firmware"
+        depends on !X86_64 && !X86_PAE
+        default y if OLPC
+        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.
+
 endif # X86_32
 
 config K8_NB
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index 6be33d83c716..8e6218550e77 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -70,6 +70,14 @@ struct sys_desc_table {
         __u8  table[14];
 };
 
+/* Gleaned from OFW's set-parameters in cpu/x86/pc/linux.fth */
+struct olpc_ofw_header {
+        __u32 ofw_magic;        /* OFW signature */
+        __u32 ofw_version;
+        __u32 cif_handler;      /* callback into OFW */
+        __u32 irq_desc_table;
+} __attribute__((packed));
+
 struct efi_info {
         __u32 efi_loader_signature;
         __u32 efi_systab;
@@ -92,7 +100,8 @@ struct boot_params {
         __u8  hd0_info[16];     /* obsolete! */         /* 0x080 */
         __u8  hd1_info[16];     /* obsolete! */         /* 0x090 */
         struct sys_desc_table sys_desc_table;           /* 0x0a0 */
-        __u8  _pad4[144];                               /* 0x0b0 */
+        struct olpc_ofw_header olpc_ofw_header;         /* 0x0b0 */
+        __u8  _pad4[128];                               /* 0x0c0 */
         struct edid_info edid_info;                     /* 0x140 */
         struct efi_info efi_info;                       /* 0x1c0 */
         __u32 alt_mem_k;                                /* 0x1e0 */
diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
new file mode 100644
index 000000000000..3e63d857c48f
--- /dev/null
+++ b/arch/x86/include/asm/olpc_ofw.h
@@ -0,0 +1,31 @@
+#ifndef _ASM_X86_OLPC_OFW_H
+#define _ASM_X86_OLPC_OFW_H
+
+/* index into the page table containing the entry OFW occupies */
+#define OLPC_OFW_PDE_NR 1022
+
+#define OLPC_OFW_SIG 0x2057464F /* aka "OFW " */
+
+#ifdef CONFIG_OLPC_OPENFIRMWARE
+
+/* 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)
+
+extern int __olpc_ofw(const char *name, int nr_args, void **args, int nr_res,
+                void **res);
+
+/* determine whether OFW is available and lives in the proper memory */
+extern void olpc_ofw_detect(void);
+
+/* install OFW's pde permanently into the kernel's pgtable */
+extern void setup_olpc_ofw_pgd(void);
+
+#else /* !CONFIG_OLPC_OPENFIRMWARE */
+
+static inline void olpc_ofw_detect(void) { }
+static inline void setup_olpc_ofw_pgd(void) { }
+
+#endif /* !CONFIG_OLPC_OPENFIRMWARE */
+
+#endif /* _ASM_X86_OLPC_OFW_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index e77b22083721..0925676266bd 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_SCx200)		+= scx200.o
 scx200-y                        += scx200_32.o
 
 obj-$(CONFIG_OLPC)              += olpc.o
+obj-$(CONFIG_OLPC_OPENFIRMWARE) += olpc_ofw.o
 obj-$(CONFIG_X86_MRST)          += mrst.o
 
 microcode-y                             := microcode_core.o
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 37c3d4b17d85..ff4c453e13f3 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -131,6 +131,12 @@ ENTRY(startup_32)
         movsl
 1:
 
+#ifdef CONFIG_OLPC_OPENFIRMWARE
+        /* save OFW's pgdir table for later use when calling into OFW */
+        movl %cr3, %eax
+        movl %eax, pa(olpc_ofw_pgd)
+#endif
+
 #ifdef CONFIG_PARAVIRT
         /* This is can only trip for a broken bootloader... */
         cmpw $0x207, pa(boot_params + BP_version)
diff --git a/arch/x86/kernel/olpc.c b/arch/x86/kernel/olpc.c
index 8297160c41b3..156605281f56 100644
--- a/arch/x86/kernel/olpc.c
+++ b/arch/x86/kernel/olpc.c
@@ -21,10 +21,7 @@
 #include <asm/geode.h>
 #include <asm/setup.h>
 #include <asm/olpc.h>
-
-#ifdef CONFIG_OPEN_FIRMWARE
-#include <asm/ofw.h>
-#endif
+#include <asm/olpc_ofw.h>
 
 struct olpc_platform_t olpc_platform_info;
 EXPORT_SYMBOL_GPL(olpc_platform_info);
@@ -188,14 +185,15 @@ err:
 }
 EXPORT_SYMBOL_GPL(olpc_ec_cmd);
 
-#ifdef CONFIG_OPEN_FIRMWARE
+#ifdef CONFIG_OLPC_OPENFIRMWARE
 static void __init platform_detect(void)
 {
         size_t propsize;
         __be32 rev;
+        void *args[] = { NULL, "board-revision-int", &rev, (void *)4 };
+        void *res[] = { &propsize };
 
-        if (ofw("getprop", 4, 1, NULL, "board-revision-int", &rev, 4,
-                        &propsize) || propsize != 4) {
+        if (olpc_ofw("getprop", args, res) || propsize != 4) {
                 printk(KERN_ERR "ofw: getprop call failed!\n");
                 rev = cpu_to_be32(0);
         }
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
new file mode 100644
index 000000000000..469ee4384295
--- /dev/null
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -0,0 +1,104 @@
+#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);
+        early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
+}
+
+int __olpc_ofw(const char *name, int nr_args, 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);
+
+/* 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);
+}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b4ae4acbd031..b008e7883207 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -102,6 +102,7 @@
 
 #include <asm/paravirt.h>
 #include <asm/hypervisor.h>
+#include <asm/olpc_ofw.h>
 
 #include <asm/percpu.h>
 #include <asm/topology.h>
@@ -736,10 +737,15 @@ void __init setup_arch(char **cmdline_p)
         /* VMI may relocate the fixmap; do this before touching ioremap area */
         vmi_init();
 
+        /* OFW also may relocate the fixmap */
+        olpc_ofw_detect();
+
         early_trap_init();
         early_cpu_init();
         early_ioremap_init();
 
+        setup_olpc_ofw_pgd();
+
         ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
         screen_info = boot_params.screen_info;
         edid_info = boot_params.edid_info;