ARM: move VFP init to an earlier boot stage

[firefly-linux-kernel-4.4.55.git] / arch / arm / vfp / vfpmodule.c

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 5dfbb0b8e7f4484ddeb97974080a51bfaec0dc3e..452fb3ad68aafea3c24236cb4b70d850528df1b8 100644 (file)
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -20,6 +20,7 @@
 #include <linux/init.h>
 #include <linux/uaccess.h>
 #include <linux/user.h>
+#include <linux/export.h>
 
 #include <asm/cp15.h>
 #include <asm/cputype.h>
@@ -648,6 +649,52 @@ static int vfp_hotplug(struct notifier_block *b, unsigned long action,
        return NOTIFY_OK;
 }
 
+#ifdef CONFIG_KERNEL_MODE_NEON
+
+/*
+ * Kernel-side NEON support functions
+ */
+void kernel_neon_begin(void)
+{
+       struct thread_info *thread = current_thread_info();
+       unsigned int cpu;
+       u32 fpexc;
+
+       /*
+        * Kernel mode NEON is only allowed outside of interrupt context
+        * with preemption disabled. This will make sure that the kernel
+        * mode NEON register contents never need to be preserved.
+        */
+       BUG_ON(in_interrupt());
+       cpu = get_cpu();
+
+       fpexc = fmrx(FPEXC) | FPEXC_EN;
+       fmxr(FPEXC, fpexc);
+
+       /*
+        * Save the userland NEON/VFP state. Under UP,
+        * the owner could be a task other than 'current'
+        */
+       if (vfp_state_in_hw(cpu, thread))
+               vfp_save_state(&thread->vfpstate, fpexc);
+#ifndef CONFIG_SMP
+       else if (vfp_current_hw_state[cpu] != NULL)
+               vfp_save_state(vfp_current_hw_state[cpu], fpexc);
+#endif
+       vfp_current_hw_state[cpu] = NULL;
+}
+EXPORT_SYMBOL(kernel_neon_begin);
+
+void kernel_neon_end(void)
+{
+       /* Disable the NEON/VFP unit. */
+       fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+       put_cpu();
+}
+EXPORT_SYMBOL(kernel_neon_end);
+
+#endif /* CONFIG_KERNEL_MODE_NEON */
+
 /*
  * VFP support code initialisation.
  */
@@ -731,4 +778,4 @@ static int __init vfp_init(void)
        return 0;
 }
 
-late_initcall(vfp_init);
+core_initcall(vfp_init);