From: H. Peter Anvin on
Hi Linus,

The following changes since commit fc1caf6eafb30ea185720e29f7f5eccca61ecd60:

Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 (2010-08-05 16:02:01 -0700)

are available in the git repository at:

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

Andres Salomon (4):
x86, olpc: Add support for calling into OpenFirmware
x86, olpc: Add comment about implicit optimization barrier
x86, olpc: Use pr_debug() for EC commands
x86, olpc: Constify an olpc_ofw() arg

Documentation/x86/zero-page.txt | 1 +
arch/x86/Kconfig | 9 +++
arch/x86/include/asm/bootparam.h | 11 ++++-
arch/x86/include/asm/olpc_ofw.h | 31 +++++++++++
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/head_32.S | 6 ++
arch/x86/kernel/olpc.c | 20 +++----
arch/x86/kernel/olpc_ofw.c | 106 ++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/setup.c | 6 ++
9 files changed, 178 insertions(+), 13 deletions(-)
create mode 100644 arch/x86/include/asm/olpc_ofw.h
create mode 100644 arch/x86/kernel/olpc_ofw.c

diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index feb37e1..cf5437d 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 dcb0593..71c194d 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 6be33d8..8e62185 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 0000000..08fde47
--- /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, 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 */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index e77b220..0925676 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 37c3d4b..ff4c453 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 8297160..0e0cdde 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);
@@ -145,7 +142,7 @@ restart:
* 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 @@ restart:
" 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 @@ restart:
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 @@ 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;
+ 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);
}
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
new file mode 100644
index 0000000..3218aa7
--- /dev/null
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -0,0 +1,106 @@
+#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);
+}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b4ae4ac..b008e78 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;
--
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