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Commit 8e140362 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 1c9d3df5

arch/arm/vfp/vfpmodule.c

+15 −0
Original line number Diff line number Diff line
@@ -264,6 +264,18 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs) 
		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 @@ static int __init vfp_init(void) 
	 * 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 @@ static int __init vfp_init(void) 
	} 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,