Merge tag 'arm-vfp-refactor-for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux into devel-stabledevel-stable

Refactor VFP support code and reimplement in C

The VFP related changes to permit kernel mode NEON in softirq context
resulted in some issues regarding en/disabling of sofirqs from asm code,
and this made it clear that it would be better to handle more of it from
C code.

Given that we already have infrastructure that associates undefined
instruction exceptions with handler code based on value/mask pairs, we
can easily move the dispatch of VFP and NEON instructions to C code once
we reimplement the actual VFP support routine (which reasons about how
to deal with the exception and whether any emulation is needed) in C
code first.

With those out of the way, we can drop the partial decoding logic in asm
that reasons about which ISA is being used by user space, as the
remaining cases are all 32-bit ARM only. This leaves a FPE specific
routine with some iWMMXT logic that is easily duplicated in C as well,
allowing us to move the FPE asm code into the FPE asm source file, and
out of the shared entry code.

1 files changed, 16 insertions, 1 deletions

diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 7f092cb55a41..943ffcf069d2 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -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;
@@ -66,7 +67,6 @@ struct thread_info {
 	__u32			cpu_domain;	/* cpu domain */
 	struct cpu_context_save	cpu_context;	/* cpu context */
 	__u32			abi_syscall;	/* ABI type and syscall nr */
-	__u8			used_cp[16];	/* thread used copro */
 	unsigned long		tp_value[2];	/* TLS registers */
 	union fp_state		fpstate __attribute__((aligned(8)));
 	union vfp_state		vfpstate;
@@ -105,6 +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 *);