From 2498814fcb3068f19b82b1519b4038721f61af43 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 23 Apr 2012 15:38:28 +0100 Subject: [PATCH] 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: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/thread_info.h | 7 +++ arch/arm/kernel/signal.c | 55 ++------------------- arch/arm/vfp/vfpmodule.c | 79 ++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+), 51 deletions(-) diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index d4c24d412a8d..0f04d84582e1 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -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 /* diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 7cb532fc8aa4..d68d1b694680 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -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); + if (err) + return -EFAULT; - /* - * 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); - - 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 diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 858748eaa144..05872d92fca2 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include #include #include @@ -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