* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
-#include <linux/module.h>
#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>
+#include <asm/system_info.h>
#include <asm/thread_notify.h>
#include <asm/vfp.h>
void vfp_null_entry(void);
void (*vfp_vector)(void) = vfp_null_entry;
-union vfp_state *last_VFP_context[NR_CPUS];
/*
* Dual-use variable.
unsigned int VFP_arch;
/*
+ * The pointer to the vfpstate structure of the thread which currently
+ * owns the context held in the VFP hardware, or NULL if the hardware
+ * context is invalid.
+ *
+ * For UP, this is sufficient to tell which thread owns the VFP context.
+ * However, for SMP, we also need to check the CPU number stored in the
+ * saved state too to catch migrations.
+ */
+union vfp_state *vfp_current_hw_state[NR_CPUS];
+
+/*
+ * Is 'thread's most up to date state stored in this CPUs hardware?
+ * Must be called from non-preemptible context.
+ */
+static bool vfp_state_in_hw(unsigned int cpu, struct thread_info *thread)
+{
+#ifdef CONFIG_SMP
+ if (thread->vfpstate.hard.cpu != cpu)
+ return false;
+#endif
+ return vfp_current_hw_state[cpu] == &thread->vfpstate;
+}
+
+/*
+ * Force a reload of the VFP context from the thread structure. We do
+ * this by ensuring that access to the VFP hardware is disabled, and
+ * clear vfp_current_hw_state. Must be called from non-preemptible context.
+ */
+static void vfp_force_reload(unsigned int cpu, struct thread_info *thread)
+{
+ if (vfp_state_in_hw(cpu, thread)) {
+ fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+ vfp_current_hw_state[cpu] = NULL;
+ }
+#ifdef CONFIG_SMP
+ thread->vfpstate.hard.cpu = NR_CPUS;
+#endif
+}
+
+/*
* Per-thread VFP initialization.
*/
static void vfp_thread_flush(struct thread_info *thread)
union vfp_state *vfp = &thread->vfpstate;
unsigned int cpu;
- memset(vfp, 0, sizeof(union vfp_state));
-
- vfp->hard.fpexc = FPEXC_EN;
- vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
-
/*
* Disable VFP to ensure we initialize it first. We must ensure
- * that the modification of last_VFP_context[] and hardware disable
- * are done for the same CPU and without preemption.
+ * that the modification of vfp_current_hw_state[] and hardware
+ * disable are done for the same CPU and without preemption.
+ *
+ * Do this first to ensure that preemption won't overwrite our
+ * state saving should access to the VFP be enabled at this point.
*/
cpu = get_cpu();
- if (last_VFP_context[cpu] == vfp)
- last_VFP_context[cpu] = NULL;
+ if (vfp_current_hw_state[cpu] == vfp)
+ vfp_current_hw_state[cpu] = NULL;
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
put_cpu();
+
+ memset(vfp, 0, sizeof(union vfp_state));
+
+ vfp->hard.fpexc = FPEXC_EN;
+ vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
+#ifdef CONFIG_SMP
+ vfp->hard.cpu = NR_CPUS;
+#endif
}
static void vfp_thread_exit(struct thread_info *thread)
union vfp_state *vfp = &thread->vfpstate;
unsigned int cpu = get_cpu();
- if (last_VFP_context[cpu] == vfp)
- last_VFP_context[cpu] = NULL;
+ if (vfp_current_hw_state[cpu] == vfp)
+ vfp_current_hw_state[cpu] = NULL;
put_cpu();
}
vfp_sync_hwstate(parent);
thread->vfpstate = parent->vfpstate;
+#ifdef CONFIG_SMP
+ thread->vfpstate.hard.cpu = NR_CPUS;
+#endif
}
/*
* case the thread migrates to a different CPU. The
* restoring is done lazily.
*/
- if ((fpexc & FPEXC_EN) && last_VFP_context[cpu]) {
- vfp_save_state(last_VFP_context[cpu], fpexc);
- last_VFP_context[cpu]->hard.cpu = cpu;
- }
- /*
- * Thread migration, just force the reloading of the
- * state on the new CPU in case the VFP registers
- * contain stale data.
- */
- if (thread->vfpstate.hard.cpu != cpu)
- last_VFP_context[cpu] = NULL;
+ if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu])
+ vfp_save_state(vfp_current_hw_state[cpu], fpexc);
#endif
/*
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)
set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
}
-#ifdef CONFIG_PM
-#include <linux/syscore_ops.h>
-
+#ifdef CONFIG_CPU_PM
static int vfp_pm_suspend(void)
{
struct thread_info *ti = current_thread_info();
}
/* clear any information we had about last context state */
- memset(last_VFP_context, 0, sizeof(last_VFP_context));
+ memset(vfp_current_hw_state, 0, sizeof(vfp_current_hw_state));
return 0;
}
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
}
-static struct syscore_ops vfp_pm_syscore_ops = {
- .suspend = vfp_pm_suspend,
- .resume = vfp_pm_resume,
+static int vfp_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd,
+ void *v)
+{
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ vfp_pm_suspend();
+ break;
+ case CPU_PM_ENTER_FAILED:
+ case CPU_PM_EXIT:
+ vfp_pm_resume();
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block vfp_cpu_pm_notifier_block = {
+ .notifier_call = vfp_cpu_pm_notifier,
};
static void vfp_pm_init(void)
{
- register_syscore_ops(&vfp_pm_syscore_ops);
+ cpu_pm_register_notifier(&vfp_cpu_pm_notifier_block);
}
#else
static inline void vfp_pm_init(void) { }
-#endif /* CONFIG_PM */
+#endif /* CONFIG_CPU_PM */
+/*
+ * Ensure that the VFP state stored in 'thread->vfpstate' is up to date
+ * with the hardware state.
+ */
void vfp_sync_hwstate(struct thread_info *thread)
{
unsigned int cpu = get_cpu();
- /*
- * If the thread we're interested in is the current owner of the
- * hardware VFP state, then we need to save its state.
- */
- if (last_VFP_context[cpu] == &thread->vfpstate) {
+ if (vfp_state_in_hw(cpu, thread)) {
u32 fpexc = fmrx(FPEXC);
/*
put_cpu();
}
+/* Ensure that the thread reloads the hardware VFP state on the next use. */
void vfp_flush_hwstate(struct thread_info *thread)
{
unsigned int cpu = get_cpu();
+ vfp_force_reload(cpu, 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);
+
/*
- * If the thread we're interested in is the current owner of the
- * hardware VFP state, then we need to save its state.
+ * Copy the floating point registers. There can be unused
+ * registers see asm/hwcap.h for details.
*/
- if (last_VFP_context[cpu] == &thread->vfpstate) {
- u32 fpexc = fmrx(FPEXC);
+ 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);
- fmxr(FPEXC, fpexc & ~FPEXC_EN);
+ /*
+ * 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);
- /*
- * Set the context to NULL to force a reload the next time
- * the thread uses the VFP.
- */
- last_VFP_context[cpu] = NULL;
- }
+ if (err)
+ return -EFAULT;
+
+ /* Ensure that VFP is disabled. */
+ vfp_flush_hwstate(thread);
-#ifdef CONFIG_SMP
/*
- * For SMP we still have to take care of the case where the thread
- * migrates to another CPU and then back to the original CPU on which
- * the last VFP user is still the same thread. Mark the thread VFP
- * state as belonging to a non-existent CPU so that the saved one will
- * be reloaded in the above case.
+ * As per the PCS, clear the length and stride bits for function
+ * entry.
*/
- thread->vfpstate.hard.cpu = NR_CPUS;
-#endif
- put_cpu();
+ 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;
}
/*
void *hcpu)
{
if (action == CPU_DYING || action == CPU_DYING_FROZEN) {
- unsigned int cpu = (long)hcpu;
- last_VFP_context[cpu] = NULL;
+ vfp_force_reload((long)hcpu, current_thread_info());
} else if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
vfp_enable(NULL);
return NOTIFY_OK;
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.
} 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 */
printk("implementor %02x architecture %d part %02x variant %x rev %x\n",
(vfpsid & FPSID_IMPLEMENTER_MASK) >> FPSID_IMPLEMENTER_BIT,
elf_hwcap |= HWCAP_VFPv3D16;
}
#endif
-#ifdef CONFIG_NEON
/*
* Check for the presence of the Advanced SIMD
* load/store instructions, integer and single
* for NEON if the hardware has the MVFR registers.
*/
if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
+#ifdef CONFIG_NEON
if ((fmrx(MVFR1) & 0x000fff00) == 0x00011100)
elf_hwcap |= HWCAP_NEON;
- }
#endif
+ if ((fmrx(MVFR1) & 0xf0000000) == 0x10000000)
+ elf_hwcap |= HWCAP_VFPv4;
+ }
}
return 0;
}
projects / linux-flexiantxendom0-3.2.10.git / blobdiff