[ARM] Fix VFP initialisation issue for SMP systems
When we install the handlers for context switching, we must enable
VFP on all CPU cores, otherwise undefined (and random) effects
occur.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index e26cc1f..490d9d1 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -264,6 +264,18 @@
vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
}
+static void vfp_enable(void *unused)
+{
+ u32 access = get_copro_access();
+
+ /*
+ * Enable full access to VFP (cp10 and cp11)
+ */
+ set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
+}
+
+#include <linux/smp.h>
+
/*
* VFP support code initialisation.
*/
@@ -288,6 +300,7 @@
* we just need to read the VFPSID register.
*/
vfpsid = fmrx(FPSID);
+ barrier();
printk(KERN_INFO "VFP support v0.3: ");
if (VFP_arch) {
@@ -301,6 +314,8 @@
} else if (vfpsid & FPSID_NODOUBLE) {
printk("no double precision support\n");
} else {
+ smp_call_function(vfp_enable, NULL, 1, 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,