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Commit 2498814f authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

ARM: 7399/1: vfp: move user vfp state save/restore code out of signal.c 



The user VFP state must be preserved (subject to ucontext modifications)
across invocation of a signal handler and this is currently handled by
vfp_{preserve,restore}_context in signal.c

Since this code requires intimate low-level knowledge of the VFP state,
this patch moves it into vfpmodule.c.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ab4d5368

arch/arm/include/asm/thread_info.h

+7 −0
Original line number Diff line number Diff line
@@ -118,6 +118,13 @@ extern void iwmmxt_task_switch(struct thread_info *); 
extern void vfp_sync_hwstate(struct thread_info *);

extern void vfp_flush_hwstate(struct thread_info *);



struct user_vfp;

struct user_vfp_exc;



extern int vfp_preserve_user_clear_hwstate(struct user_vfp __user *,

					   struct user_vfp_exc __user *);

extern int vfp_restore_user_hwstate(struct user_vfp __user *,

				    struct user_vfp_exc __user *);

#endif



/*

arch/arm/kernel/signal.c

+4 −51
Original line number Diff line number Diff line
@@ -180,44 +180,23 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) 


static int preserve_vfp_context(struct vfp_sigframe __user *frame)

{

	struct thread_info *thread = current_thread_info();

	struct vfp_hard_struct *h = &thread->vfpstate.hard;

	const unsigned long magic = VFP_MAGIC;

	const unsigned long size = VFP_STORAGE_SIZE;

	int err = 0;



	vfp_sync_hwstate(thread);

	__put_user_error(magic, &frame->magic, err);

	__put_user_error(size, &frame->size, err);



	/*

	 * Copy the floating point registers. There can be unused

	 * registers see asm/hwcap.h for details.

	 */

	err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs,

			      sizeof(h->fpregs));

	/*

	 * Copy the status and control register.

	 */

	__put_user_error(h->fpscr, &frame->ufp.fpscr, err);



	/*

	 * Copy the exception registers.

	 */

	__put_user_error(h->fpexc, &frame->ufp_exc.fpexc, err);

	__put_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);

	__put_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);

	if (err)

		return -EFAULT;



	return err ? -EFAULT : 0;

	return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc);

}



static int restore_vfp_context(struct vfp_sigframe __user *frame)

{

	struct thread_info *thread = current_thread_info();

	struct vfp_hard_struct *h = &thread->vfpstate.hard;

	unsigned long magic;

	unsigned long size;

	unsigned long fpexc;

	int err = 0;



	__get_user_error(magic, &frame->magic, err);
@@ -228,33 +207,7 @@ static int restore_vfp_context(struct vfp_sigframe __user *frame) 
	if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)

		return -EINVAL;



	vfp_flush_hwstate(thread);



	/*

	 * Copy the floating point registers. There can be unused

	 * registers see asm/hwcap.h for details.

	 */

	err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs,

				sizeof(h->fpregs));

	/*

	 * Copy the status and control register.

	 */

	__get_user_error(h->fpscr, &frame->ufp.fpscr, err);



	/*

	 * Sanitise and restore the exception registers.

	 */

	__get_user_error(fpexc, &frame->ufp_exc.fpexc, err);

	/* Ensure the VFP is enabled. */

	fpexc |= FPEXC_EN;

	/* Ensure FPINST2 is invalid and the exception flag is cleared. */

	fpexc &= ~(FPEXC_EX | FPEXC_FP2V);

	h->fpexc = fpexc;



	__get_user_error(h->fpinst, &frame->ufp_exc.fpinst, err);

	__get_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err);



	return err ? -EFAULT : 0;

	return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc);

}



#endif

arch/arm/vfp/vfpmodule.c

+79 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
#include <linux/sched.h>

#include <linux/smp.h>

#include <linux/init.h>

#include <linux/uaccess.h>

#include <linux/user.h>



#include <asm/cp15.h>

#include <asm/cputype.h>
@@ -528,6 +530,83 @@ void vfp_flush_hwstate(struct thread_info *thread) 
	put_cpu();

}



/*

 * Save the current VFP state into the provided structures and prepare

 * for entry into a new function (signal handler).

 */

int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp,

				    struct user_vfp_exc __user *ufp_exc)

{

	struct thread_info *thread = current_thread_info();

	struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;

	int err = 0;



	/* Ensure that the saved hwstate is up-to-date. */

	vfp_sync_hwstate(thread);



	/*

	 * Copy the floating point registers. There can be unused

	 * registers see asm/hwcap.h for details.

	 */

	err |= __copy_to_user(&ufp->fpregs, &hwstate->fpregs,

			      sizeof(hwstate->fpregs));

	/*

	 * Copy the status and control register.

	 */

	__put_user_error(hwstate->fpscr, &ufp->fpscr, err);



	/*

	 * Copy the exception registers.

	 */

	__put_user_error(hwstate->fpexc, &ufp_exc->fpexc, err);

	__put_user_error(hwstate->fpinst, &ufp_exc->fpinst, err);

	__put_user_error(hwstate->fpinst2, &ufp_exc->fpinst2, err);



	if (err)

		return -EFAULT;

	return 0;

}



/* Sanitise and restore the current VFP state from the provided structures. */

int vfp_restore_user_hwstate(struct user_vfp __user *ufp,

			     struct user_vfp_exc __user *ufp_exc)

{

	struct thread_info *thread = current_thread_info();

	struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;

	unsigned long fpexc;

	int err = 0;



	vfp_flush_hwstate(thread);



	/*

	 * Copy the floating point registers. There can be unused

	 * registers see asm/hwcap.h for details.

	 */

	err |= __copy_from_user(&hwstate->fpregs, &ufp->fpregs,

				sizeof(hwstate->fpregs));

	/*

	 * Copy the status and control register.

	 */

	__get_user_error(hwstate->fpscr, &ufp->fpscr, err);



	/*

	 * Sanitise and restore the exception registers.

	 */

	__get_user_error(fpexc, &ufp_exc->fpexc, err);



	/* Ensure the VFP is enabled. */

	fpexc |= FPEXC_EN;



	/* Ensure FPINST2 is invalid and the exception flag is cleared. */

	fpexc &= ~(FPEXC_EX | FPEXC_FP2V);

	hwstate->fpexc = fpexc;



	__get_user_error(hwstate->fpinst, &ufp_exc->fpinst, err);

	__get_user_error(hwstate->fpinst2, &ufp_exc->fpinst2, err);



	return err ? -EFAULT : 0;

}



/*

 * VFP hardware can lose all context when a CPU goes offline.

 * As we will be running in SMP mode with CPU hotplug, we will save the