x86, olpc: Rework BIOS signature check

The XO-1.5 laptop is not currently detected as an OLPC machine because
it fails this XO-1-centric check.

Now that we have OLPC OFW support in the kernel, a more sensible
check is to see if we found OFW during boot and check the architecture
property.

Also remove a now-meaningless codepath, as we're always going to have
OFW support with OLPC.

Signed-off-by: Daniel Drake <dsd@laptop.org>
LKML-Reference: <20100923162846.D8D409D401B@zog.reactivated.net>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 25 insertions, 33 deletions

diff --git a/arch/x86/kernel/olpc.c b/arch/x86/kernel/olpc.c
index 635888cf050d..37c49934c785 100644
--- a/arch/x86/kernel/olpc.c
+++ b/arch/x86/kernel/olpc.c
@@ -183,8 +183,21 @@ err:
 }
 EXPORT_SYMBOL_GPL(olpc_ec_cmd);
 
-#ifdef CONFIG_OLPC_OPENFIRMWARE
-static void __init platform_detect(void)
+static bool __init check_ofw_architecture(void)
+{
+        size_t propsize;
+        char olpc_arch[5];
+        const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 };
+        void *res[] = { &propsize };
+
+        if (olpc_ofw("getprop", args, res)) {
+                printk(KERN_ERR "ofw: getprop call failed!\n");
+                return false;
+        }
+        return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;
+}
+
+static u32 __init get_board_revision(void)
 {
         size_t propsize;
         __be32 rev;
@@ -193,46 +206,27 @@ static void __init platform_detect(void)
 
         if (olpc_ofw("getprop", args, res) || propsize != 4) {
                 printk(KERN_ERR "ofw: getprop call failed!\n");
-                rev = cpu_to_be32(0);
+                return cpu_to_be32(0);
         }
-        olpc_platform_info.boardrev = be32_to_cpu(rev);
+        return be32_to_cpu(rev);
 }
-#else
-static void __init platform_detect(void)
+
+static bool __init platform_detect(void)
 {
-        /* stopgap until OFW support is added to the kernel */
-        olpc_platform_info.boardrev = olpc_board(0xc2);
+        if (!check_ofw_architecture())
+                return false;
+        olpc_platform_info.flags |= OLPC_F_PRESENT;
+        olpc_platform_info.boardrev = get_board_revision();
+        return true;
 }
-#endif
 
 static int __init olpc_init(void)
 {
-        unsigned char *romsig;
-
-        /* The ioremap check is dangerous; limit what we run it on */
-        if (!is_geode() || cs5535_has_vsa2())
+        if (!olpc_ofw_present() || !platform_detect())
                 return 0;
 
         spin_lock_init(&ec_lock);
 
-        romsig = ioremap(0xffffffc0, 16);
-        if (!romsig)
-                return 0;
-
-        if (strncmp(romsig, "CL1   Q", 7))
-                goto unmap;
-        if (strncmp(romsig+6, romsig+13, 3)) {
-                printk(KERN_INFO "OLPC BIOS signature looks invalid.  "
-                                "Assuming not OLPC\n");
-                goto unmap;
-        }
-
-        printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
-        olpc_platform_info.flags |= OLPC_F_PRESENT;
-
-        /* get the platform revision */
-        platform_detect();
-
         /* assume B1 and above models always have a DCON */
         if (olpc_board_at_least(olpc_board(0xb1)))
                 olpc_platform_info.flags |= OLPC_F_DCON;
@@ -254,8 +248,6 @@ static int __init olpc_init(void)
                         olpc_platform_info.boardrev >> 4,
                         olpc_platform_info.ecver);
 
-unmap:
-        iounmap(romsig);
         return 0;
 }