Merge branch 'x86-olpc-for-linus' of...

Merge branch 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-olpc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, olpc: Constify an olpc_ofw() arg
  x86, olpc: Use pr_debug() for EC commands
  x86, olpc: Add comment about implicit optimization barrier
  x86, olpc: Add support for calling into OpenFirmware

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

arch/x86/Kconfig

@@ -2060,6 +2060,15 @@ 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

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 */

arch/x86/include/asm/olpc_ofw.h

+#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, const 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 */

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

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)

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);
@@ -145,7 +142,7 @@ int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
 	 * The OBF flag will sometimes misbehave due to what we believe
 	 * is a hardware quirk..
 	 */
-	printk(KERN_DEBUG "olpc-ec:  running cmd 0x%x\n", cmd);
+	pr_devel("olpc-ec:  running cmd 0x%x\n", cmd);
 	outb(cmd, 0x6c);
 
 	if (wait_on_ibf(0x6c, 0)) {
@@ -162,8 +159,7 @@ int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
 						" EC accept data!\n");
 				goto err;
 			}
-			printk(KERN_DEBUG "olpc-ec:  sending cmd arg 0x%x\n",
-					inbuf[i]);
+			pr_devel("olpc-ec:  sending cmd arg 0x%x\n", inbuf[i]);
 			outb(inbuf[i], 0x68);
 		}
 	}
@@ -176,8 +172,7 @@ int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
 				goto restart;
 			}
 			outbuf[i] = inb(0x68);
-			printk(KERN_DEBUG "olpc-ec:  received 0x%x\n",
-					outbuf[i]);
+			pr_devel("olpc-ec:  received 0x%x\n", outbuf[i]);
 		}
 	}
 
@@ -188,14 +183,15 @@ int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
 }
 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;
+	const 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);
 	}

arch/x86/kernel/olpc_ofw.c

+#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);
+
+/* 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);
+}

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;