commit 2c952e06e4f57716109b609956eda28c900faac0
author Jayachandran C <jchandra@broadcom.com> Mon Jun 10 06:30:00 2013 +0000
committer Ralf Baechle <ralf@linux-mips.org> Thu Jun 13 17:46:41 2013 +0200
tree 39dc9361773009cdcfdc1e0e1752b446259d7cef
parent 79f8511c83f13689913f54d2f189297c226ec064

MIPS: Move cop2 save/restore to switch_to()

Move the common code for saving and restoring platform specific COP2
registers to switch_to(). This will make supporting new platforms (like
Netlogic XLP) easier.

The platform specific COP2 definitions are to be specified in
asm/processor.h and in asm/cop2.h.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5411/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/switch_to.h

diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index fd16bcb..eb0af15 100644
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -15,6 +15,7 @@
 #include <asm/cpu-features.h>
 #include <asm/watch.h>
 #include <asm/dsp.h>
+#include <asm/cop2.h>
 
 struct task_struct;
 
@@ -66,10 +67,18 @@
 
 #define switch_to(prev, next, last)					\
 do {									\
-	u32 __usedfpu;							\
+	u32 __usedfpu, __c0_stat;					\
 	__mips_mt_fpaff_switch_to(prev);				\
 	if (cpu_has_dsp)						\
 		__save_dsp(prev);					\
+	if (cop2_present && (KSTK_STATUS(prev) & ST0_CU2)) {		\
+		if (cop2_lazy_restore)					\
+			KSTK_STATUS(prev) &= ~ST0_CU2;			\
+		__c0_stat = read_c0_status();				\
+		write_c0_status(__c0_stat | ST0_CU2);			\
+		cop2_save(&prev->thread.cp2);				\
+		write_c0_status(__c0_stat & ~ST0_CU2);			\
+	}								\
 	__clear_software_ll_bit();					\
 	__usedfpu = test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU);	\
 	(last) = resume(prev, next, task_thread_info(next), __usedfpu); \
@@ -77,6 +86,14 @@
 
 #define finish_arch_switch(prev)					\
 do {									\
+	u32 __c0_stat;							\
+	if (cop2_present && !cop2_lazy_restore &&			\
+			(KSTK_STATUS(current) & ST0_CU2)) {		\
+		__c0_stat = read_c0_status();				\
+		write_c0_status(__c0_stat | ST0_CU2);			\
+		cop2_restore(&current->thread.cp2);			\
+		write_c0_status(__c0_stat & ~ST0_CU2);			\
+	}								\
 	if (cpu_has_dsp)						\
 		__restore_dsp(current);					\
 	if (cpu_has_userlocal)						\