From 191d0d24b632eb69767705acded5cbf7449ad457 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 12 Jan 2010 14:50:43 +0900 Subject: sh: Tidy up the sh bios VBR handling. This moves the VBR handling out of the main trap handling code and in to the sh-bios helper code. A couple of accessors are added in order to permit other kernel code to get at the VBR value for state save/restore paths. Signed-off-by: Paul Mundt --- arch/sh/kernel/sh_bios.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'arch/sh/kernel/sh_bios.c') diff --git a/arch/sh/kernel/sh_bios.c b/arch/sh/kernel/sh_bios.c index c852f7805728..2a5f2e0d505d 100644 --- a/arch/sh/kernel/sh_bios.c +++ b/arch/sh/kernel/sh_bios.c @@ -55,3 +55,40 @@ void sh_bios_shutdown(unsigned int how) { sh_bios_call(BIOS_CALL_SHUTDOWN, how, 0, 0, 0); } + +void *gdb_vbr_vector = NULL; + +/* + * Read the old value of the VBR register to initialise the vector + * through which debug and BIOS traps are delegated by the Linux trap + * handler. + */ +void sh_bios_vbr_init(void) +{ + unsigned long vbr; + + if (unlikely(gdb_vbr_vector)) + return; + + __asm__ __volatile__ ("stc vbr, %0" : "=r" (vbr)); + + gdb_vbr_vector = (void *)(vbr + 0x100); + printk(KERN_NOTICE "Setting GDB trap vector to %p\n", gdb_vbr_vector); +} + +/** + * sh_bios_vbr_reload - Re-load the system VBR from the BIOS vector. + * + * This can be used by save/restore code to reinitialize the system VBR + * from the fixed BIOS VBR. A no-op if no BIOS VBR is known. + */ +void sh_bios_vbr_reload(void) +{ + if (gdb_vbr_vector) + __asm__ __volatile__ ( + "ldc %0, vbr" + : + : "r" (((unsigned long) gdb_vbr_vector) - 0x100) + : "memory" + ); +} -- cgit v1.2.3