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Commit 155e839a authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
Browse files

s390/kernel: dynamically allocate FP register save area 



Make the floating-point save area dynamically allocated and uses a flag
to distinguish whether a task uses floating-point or vector registers.

Signed-off-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 904818e2

arch/s390/include/asm/fpu-internal.h

+14 −5
Original line number Diff line number Diff line
@@ -8,6 +8,10 @@ 
#ifndef _ASM_S390_FPU_INTERNAL_H

#define _ASM_S390_FPU_INTERNAL_H



#define FPU_USE_VX		1	/* Vector extension is active */



#ifndef __ASSEMBLY__



#include <linux/errno.h>

#include <linux/string.h>

#include <asm/linkage.h>
@@ -16,13 +20,16 @@ 


struct fpu {

	__u32 fpc;			/* Floating-point control */

	__u32 pad;

	freg_t fprs[__NUM_FPRS];	/* Floating-point register save area */

	__u32 flags;

	union {

		void *regs;

		freg_t *fprs;		/* Floating-point register save area */

		__vector128 *vxrs;	/* Vector register save area */

	};

};



#define is_vx_fpu(fpu) (!!(fpu)->vxrs)

#define is_vx_task(tsk) (!!(tsk)->thread.fpu.vxrs)

#define is_vx_fpu(fpu) (!!((fpu)->flags & FPU_USE_VX))

#define is_vx_task(tsk) (!!((tsk)->thread.fpu.flags & FPU_USE_VX))



static inline int test_fp_ctl(u32 fpc)

{
@@ -188,4 +195,6 @@ static inline void restore_fpu_regs(struct fpu *fpu) 
		restore_fp_regs(fpu->fprs);

}



#endif



#endif /* _ASM_S390_FPU_INTERNAL_H */

arch/s390/kernel/process.c

+20 −7
Original line number Diff line number Diff line
@@ -81,8 +81,26 @@ void release_thread(struct task_struct *dead_task) 


void arch_release_task_struct(struct task_struct *tsk)

{

	if (is_vx_task(tsk))

		kfree(tsk->thread.fpu.vxrs);

	/* Free either the floating-point or the vector register save area */

	kfree(tsk->thread.fpu.regs);

}



int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)

{

	*dst = *src;



	/* Set up a new floating-point register save area */

	dst->thread.fpu.fprs = kzalloc(sizeof(freg_t) * __NUM_FPRS,

				       GFP_KERNEL|__GFP_REPEAT);

	if (!dst->thread.fpu.fprs)

		return -ENOMEM;



	/* Save the fpu registers to new thread structure. */

	save_fp_ctl(&dst->thread.fpu.fpc);

	save_fp_regs(dst->thread.fpu.fprs);

	dst->thread.fpu.flags = 0;     /* Always start with VX disabled */



	return 0;

}



int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
@@ -142,11 +160,6 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, 
	p->thread.ri_signum = 0;

	frame->childregs.psw.mask &= ~PSW_MASK_RI;



	/* Save the fpu registers to new thread structure. */

	save_fp_ctl(&p->thread.fpu.fpc);

	save_fp_regs(p->thread.fpu.fprs);

	p->thread.fpu.pad = 0;

	p->thread.fpu.vxrs = NULL;

	/* Set a new TLS ?  */

	if (clone_flags & CLONE_SETTLS) {

		unsigned long tls = frame->childregs.gprs[6];

arch/s390/kernel/traps.c

+4 −0
Original line number Diff line number Diff line
@@ -227,6 +227,7 @@ DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN, 
int alloc_vector_registers(struct task_struct *tsk)

{

	__vector128 *vxrs;

	freg_t *fprs;



	/* Allocate vector register save area. */

	vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
@@ -238,7 +239,10 @@ int alloc_vector_registers(struct task_struct *tsk) 
		save_fp_regs(tsk->thread.fpu.fprs);

	/* Copy the 16 floating point registers */

	convert_fp_to_vx(vxrs, tsk->thread.fpu.fprs);

	fprs = tsk->thread.fpu.fprs;

	tsk->thread.fpu.vxrs = vxrs;

	tsk->thread.fpu.flags |= FPU_USE_VX;

	kfree(fprs);

	if (tsk == current) {

		__ctl_set_bit(0, 17);

		restore_vx_regs(vxrs);