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Commit 2c952e06 authored by Jayachandran C's avatar Jayachandran C Committed by Ralf Baechle
Browse files

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: default avatarJayachandran 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 79f8511c

arch/mips/include/asm/cop2.h

+19 −0
Original line number Diff line number Diff line
@@ -11,6 +11,25 @@ 


#include <linux/notifier.h>



#if defined(CONFIG_CPU_CAVIUM_OCTEON)



extern void octeon_cop2_save(struct octeon_cop2_state *);

extern void octeon_cop2_restore(struct octeon_cop2_state *);



#define cop2_save(r)		octeon_cop2_save(r)

#define cop2_restore(r)		octeon_cop2_restore(r)



#define cop2_present		1

#define cop2_lazy_restore	1



#else



#define cop2_present		0

#define cop2_lazy_restore	0

#define cop2_save(r)

#define cop2_restore(r)

#endif



enum cu2_ops {

	CU2_EXCEPTION,

	CU2_LWC2_OP,

arch/mips/include/asm/processor.h

+7 −11
Original line number Diff line number Diff line
@@ -137,7 +137,7 @@ union mips_watch_reg_state { 
	struct mips3264_watch_reg_state mips3264;

};



#ifdef CONFIG_CPU_CAVIUM_OCTEON

#if defined(CONFIG_CPU_CAVIUM_OCTEON)



struct octeon_cop2_state {

	/* DMFC2 rt, 0x0201 */
@@ -182,13 +182,16 @@ struct octeon_cop2_state { 
	/* DMFC2 rt, 0x025A; DMFC2 rt, 0x025B - Pass2 */

	unsigned long	cop2_gfm_result[2];

};

#define INIT_OCTEON_COP2 {0,}

#define COP2_INIT						\

	.cp2			= {0,},



struct octeon_cvmseg_state {

	unsigned long cvmseg[CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE]

			    [cpu_dcache_line_size() / sizeof(unsigned long)];

};



#else

#define COP2_INIT

#endif



typedef struct {
@@ -245,13 +248,6 @@ struct thread_struct { 
#define FPAFF_INIT

#endif /* CONFIG_MIPS_MT_FPAFF */



#ifdef CONFIG_CPU_CAVIUM_OCTEON

#define OCTEON_INIT						\

	.cp2			= INIT_OCTEON_COP2,

#else

#define OCTEON_INIT

#endif /* CONFIG_CPU_CAVIUM_OCTEON */



#define INIT_THREAD  {						\

	/*							\

	 * Saved main processor registers			\
@@ -300,9 +296,9 @@ struct thread_struct { 
	.cp0_baduaddr		= 0,				\

	.error_code		= 0,				\

	/*							\

	 * Cavium Octeon specifics (null if not Octeon)		\

	 * Platform specific cop2 registers(null if no COP2)	\

	 */							\

	OCTEON_INIT						\

	COP2_INIT						\

}



struct task_struct;

arch/mips/include/asm/switch_to.h

+18 −1
Original line number Diff line number Diff line
@@ -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 @@ do { \ 


#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 @@ do { \ 


#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)						\

arch/mips/kernel/octeon_switch.S

+0 −27
Original line number Diff line number Diff line
@@ -40,33 +40,6 @@ 
	cpu_save_nonscratch a0

	LONG_S	ra, THREAD_REG31(a0)



	/* check if we need to save COP2 registers */

	PTR_L	t2, TASK_THREAD_INFO(a0)

	LONG_L	t0, ST_OFF(t2)

	bbit0	t0, 30, 1f



	/* Disable COP2 in the stored process state */

	li	t1, ST0_CU2

	xor	t0, t1

	LONG_S	t0, ST_OFF(t2)



	/* Enable COP2 so we can save it */

	mfc0	t0, CP0_STATUS

	or	t0, t1

	mtc0	t0, CP0_STATUS



	/* Save COP2 */

	daddu	a0, THREAD_CP2

	jal octeon_cop2_save

	dsubu	a0, THREAD_CP2



	/* Disable COP2 now that we are done */

	mfc0	t0, CP0_STATUS

	li	t1, ST0_CU2

	xor	t0, t1

	mtc0	t0, CP0_STATUS



1:

#if CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0

	/* Check if we need to store CVMSEG state */

	mfc0	t0, $11,7	/* CvmMemCtl */