parisc: Initialize the fault vector earlier in the boot process.

A fault vector on parisc needs to be 2K aligned.  Furthermore the
checksum of the fault vector needs to sum up to 0 which is being
calculated and written at runtime.

Up to now we aligned both PA20 and PA11 fault vectors on the same 4K
page in order to easily write the checksum after having mapped the
kernel read-only (by mapping this page only as read-write).
But when we want to map the kernel text and data on huge pages this
makes things harder.
So, simplify it by aligning both fault vectors on 2K boundries and write
the checksum before we map the page read-only.

Signed-off-by: Helge Deller <deller@gmx.de>

1 files changed, 15 insertions, 20 deletions

diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index b99b39f1da02..553b09855cfd 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -807,7 +807,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 }
 
 
-int __init check_ivt(void *iva)
+void __init initialize_ivt(const void *iva)
 {
 	extern u32 os_hpmc_size;
 	extern const u32 os_hpmc[];
@@ -818,8 +818,8 @@ int __init check_ivt(void *iva)
 	u32 *hpmcp;
 	u32 length;
 
-	if (strcmp((char *)iva, "cows can fly"))
-		return -1;
+	if (strcmp((const char *)iva, "cows can fly"))
+		panic("IVT invalid");
 
 	ivap = (u32 *)iva;
 
@@ -839,28 +839,23 @@ int __init check_ivt(void *iva)
 	    check += ivap[i];
 
 	ivap[5] = -check;
-
-	return 0;
 }
 	
-#ifndef CONFIG_64BIT
-extern const void fault_vector_11;
-#endif
-extern const void fault_vector_20;
 
-void __init trap_init(void)
+/* early_trap_init() is called before we set up kernel mappings and
+ * write-protect the kernel */
+void  __init early_trap_init(void)
 {
-	void *iva;
+	extern const void fault_vector_20;
 
-	if (boot_cpu_data.cpu_type >= pcxu)
-		iva = (void *) &fault_vector_20;
-	else
-#ifdef CONFIG_64BIT
-		panic("Can't boot 64-bit OS on PA1.1 processor!");
-#else
-		iva = (void *) &fault_vector_11;
+#ifndef CONFIG_64BIT
+	extern const void fault_vector_11;
+	initialize_ivt(&fault_vector_11);
 #endif
 
-	if (check_ivt(iva))
-		panic("IVT invalid");
+	initialize_ivt(&fault_vector_20);
+}
+
+void __init trap_init(void)
+{
 }