@@ -40,6 +40,7 @@ struct task_struct;
DECLARE_PER_CPU(struct task_struct *, __entry_task);
#include <asm/types.h>
+#include <asm/traps.h>
struct cpu_context_save {
__u32 r4;
@@ -104,6 +105,21 @@ extern void iwmmxt_task_restore(struct thread_info *, void *);
extern void iwmmxt_task_release(struct thread_info *);
extern void iwmmxt_task_switch(struct thread_info *);
+extern int iwmmxt_undef_handler(struct pt_regs *, u32);
+
+static inline void register_iwmmxt_undef_handler(void)
+{
+ static struct undef_hook iwmmxt_undef_hook = {
+ .instr_mask = 0x0c000e00,
+ .instr_val = 0x0c000000,
+ .cpsr_mask = MODE_MASK | PSR_T_BIT,
+ .cpsr_val = USR_MODE,
+ .fn = iwmmxt_undef_handler,
+ };
+
+ register_undef_hook(&iwmmxt_undef_hook);
+}
+
extern void vfp_sync_hwstate(struct thread_info *);
extern void vfp_flush_hwstate(struct thread_info *);
@@ -58,6 +58,15 @@
.text
.arm
+ENTRY(iwmmxt_undef_handler)
+ push {r9, r10, lr}
+ get_thread_info r10
+ mov r9, pc
+ b iwmmxt_task_enable
+ mov r0, #0
+ pop {r9, r10, pc}
+ENDPROC(iwmmxt_undef_handler)
+
/*
* Lazy switching of Concan coprocessor context
*
@@ -126,6 +126,7 @@ static int __init pj4_cp0_init(void)
pr_info("PJ4 iWMMXt v%d coprocessor enabled.\n", vers);
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
+ register_iwmmxt_undef_handler();
#endif
return 0;
@@ -166,6 +166,7 @@ static int __init xscale_cp0_init(void)
pr_info("XScale iWMMXt coprocessor detected.\n");
elf_hwcap |= HWCAP_IWMMXT;
thread_register_notifier(&iwmmxt_notifier_block);
+ register_iwmmxt_undef_handler();
#endif
} else {
pr_info("XScale DSP coprocessor detected.\n");
Define a undef hook to deal with undef exceptions triggered by iwmmxt instructions that were issued with the coprocessor disabled. This removes the dependency on the coprocessor dispatch code in entry-armv.S, which will be made NWFPE-only in a subsequent patch. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm/include/asm/thread_info.h | 16 ++++++++++++++++ arch/arm/kernel/iwmmxt.S | 9 +++++++++ arch/arm/kernel/pj4-cp0.c | 1 + arch/arm/kernel/xscale-cp0.c | 1 + 4 files changed, 27 insertions(+)