diff options
Diffstat (limited to 'arch/arm/vfp/vfpmodule.c')
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 99 |
1 files changed, 95 insertions, 4 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index a8f541b8fe9..586961929e9 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -11,12 +11,15 @@ #include <linux/types.h> #include <linux/cpu.h> #include <linux/cpu_pm.h> +#include <linux/hardirq.h> #include <linux/kernel.h> #include <linux/notifier.h> #include <linux/signal.h> #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> @@ -430,7 +433,10 @@ void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) static void vfp_enable(void *unused) { - u32 access = get_copro_access(); + u32 access; + + BUG_ON(preemptible()); + access = get_copro_access(); /* * Enable full access to VFP (cp10 and cp11) @@ -529,6 +535,93 @@ void vfp_flush_hwstate(struct thread_info *thread) } /* + * 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; + + /* Ensure that VFP is disabled. */ + vfp_flush_hwstate(thread); + + /* + * As per the PCS, clear the length and stride bits for function + * entry. + */ + hwstate->fpscr &= ~(FPSCR_LENGTH_MASK | FPSCR_STRIDE_MASK); + 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; + + /* Disable VFP to avoid corrupting the new thread state. */ + 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 * hardware state at every thread switch. We clear our held state when @@ -558,7 +651,7 @@ static int __init vfp_init(void) unsigned int cpu_arch = cpu_architecture(); if (cpu_arch >= CPU_ARCH_ARMv6) - vfp_enable(NULL); + on_each_cpu(vfp_enable, NULL, 1); /* * First check that there is a VFP that we can use. @@ -579,8 +672,6 @@ static int __init vfp_init(void) } else { hotcpu_notifier(vfp_hotplug, 0); - smp_call_function(vfp_enable, NULL, 1); - VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT; /* Extract the architecture version */ pr_cont("implementor %02x architecture %d part %02x variant %x rev %x\n", (vfpsid & FPSID_IMPLEMENTER_MASK) >> FPSID_IMPLEMENTER_BIT, |