[PATCH 5.16 10/37] ARM: early traps initialisation

Greg Kroah-Hartman
2022-03-09T16:21:48Z

From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>

commit 04e91b7324760a377a725e218b5ee783826d30f5 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm/kernel/traps.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -787,10 +787,22 @@ static inline void __init kuser_init(voi
}
#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 *vector
* 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