ARM: early traps initialisation

Provide a couple of helpers to copy the vectors and stubs, and also
to flush the copied vectors and stubs.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 195dff5..abc82df 100644 (file)
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -787,10 +787,22 @@ static inline void __init kuser_init(void *vectors)
 }
 #endif
 
+#ifndef CONFIG_CPU_V7M
+static void copy_from_lma(void *vma, void *lma_start, void *lma_end)
+{
+       memcpy(vma, lma_start, lma_end - lma_start);
+}
+
+static void flush_vectors(void *vma, size_t offset, size_t size)
+{
+       unsigned long start = (unsigned long)vma + offset;
+       unsigned long end = start + size;
+
+       flush_icache_range(start, end);
+}
+
 void __init early_trap_init(void *vectors_base)
 {
-#ifndef CONFIG_CPU_V7M
-       unsigned long vectors = (unsigned long)vectors_base;
        extern char __stubs_start[], __stubs_end[];
        extern char __vectors_start[], __vectors_end[];
        unsigned i;
@@ -811,17 +823,20 @@ void __init early_trap_init(void *vectors_base)
         * into the vector page, mapped at 0xffff0000, and ensure these
         * are visible to the instruction stream.
         */
-       memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
-       memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
+       copy_from_lma(vectors_base, __vectors_start, __vectors_end);
+       copy_from_lma(vectors_base + 0x1000, __stubs_start, __stubs_end);
 
        kuser_init(vectors_base);
 
-       flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
+       flush_vectors(vectors_base, 0, PAGE_SIZE * 2);
+}
 #else /* ifndef CONFIG_CPU_V7M */
+void __init early_trap_init(void *vectors_base)
+{
        /*
         * on V7-M there is no need to copy the vector table to a dedicated
         * memory area. The address is configurable and so a table in the kernel
         * image can be used.
         */
-#endif
 }
+#endif