* published by the Free Software Foundation.
*/
#include <linux/module.h>
-#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
+
+#include <asm/thread_notify.h>
#include <asm/vfp.h>
#include "vfpinstr.h"
void vfp_support_entry(void);
void (*vfp_vector)(void) = vfp_testing_entry;
-union vfp_state *last_VFP_context;
+union vfp_state *last_VFP_context[NR_CPUS];
/*
* Dual-use variable.
*/
unsigned int VFP_arch;
-/*
- * Per-thread VFP initialisation.
- */
-void vfp_flush_thread(union vfp_state *vfp)
+static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
{
- memset(vfp, 0, sizeof(union vfp_state));
+ struct thread_info *thread = v;
+ union vfp_state *vfp;
+ __u32 cpu = thread->cpu;
- vfp->hard.fpexc = FPEXC_ENABLE;
- vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
+ if (likely(cmd == THREAD_NOTIFY_SWITCH)) {
+ u32 fpexc = fmrx(FPEXC);
- /*
- * Disable VFP to ensure we initialise it first.
- */
- fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
+#ifdef CONFIG_SMP
+ /*
+ * On SMP, if VFP is enabled, save the old state in
+ * case the thread migrates to a different CPU. The
+ * restoring is done lazily.
+ */
+ if ((fpexc & FPEXC_ENABLE) && 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;
+#endif
- /*
- * Ensure we don't try to overwrite our newly initialised
- * state information on the first fault.
- */
- if (last_VFP_context == vfp)
- last_VFP_context = NULL;
-}
+ /*
+ * Always disable VFP so we can lazily save/restore the
+ * old state.
+ */
+ fmxr(FPEXC, fpexc & ~FPEXC_ENABLE);
+ return NOTIFY_DONE;
+ }
-/*
- * Per-thread VFP cleanup.
- */
-void vfp_release_thread(union vfp_state *vfp)
-{
- if (last_VFP_context == vfp)
- last_VFP_context = NULL;
+ vfp = &thread->vfpstate;
+ if (cmd == THREAD_NOTIFY_FLUSH) {
+ /*
+ * Per-thread VFP initialisation.
+ */
+ memset(vfp, 0, sizeof(union vfp_state));
+
+ vfp->hard.fpexc = FPEXC_ENABLE;
+ vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
+
+ /*
+ * Disable VFP to ensure we initialise it first.
+ */
+ fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
+ }
+
+ /* flush and release case: Per-thread VFP cleanup. */
+ if (last_VFP_context[cpu] == vfp)
+ last_VFP_context[cpu] = NULL;
+
+ return NOTIFY_DONE;
}
+static struct notifier_block vfp_notifier_block = {
+ .notifier_call = vfp_notifier,
+};
+
/*
* Raise a SIGFPE for the current process.
* sicode describes the signal being raised.
info.si_signo = SIGFPE;
info.si_code = sicode;
- info.si_addr = (void *)(instruction_pointer(regs) - 4);
+ info.si_addr = (void __user *)(instruction_pointer(regs) - 4);
/*
* This is the same as NWFPE, because it's not clear what
pr_debug("VFP: raising exceptions %08x\n", exceptions);
- if (exceptions == (u32)-1) {
+ if (exceptions == VFP_EXCEPTION_ERROR) {
vfp_panic("unhandled bounce");
vfp_raise_sigfpe(0, regs);
return;
/*
* These are arranged in priority order, least to highest.
*/
+ RAISE(FPSCR_DZC, FPSCR_DZE, FPE_FLTDIV);
RAISE(FPSCR_IXC, FPSCR_IXE, FPE_FLTRES);
RAISE(FPSCR_UFC, FPSCR_UFE, FPE_FLTUND);
RAISE(FPSCR_OFC, FPSCR_OFE, FPE_FLTOVF);
*/
static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs)
{
- u32 exceptions = (u32)-1;
+ u32 exceptions = VFP_EXCEPTION_ERROR;
pr_debug("VFP: emulate: INST=0x%08x SCR=0x%08x\n", inst, fpscr);
* emulate it.
*/
}
- return exceptions;
+ return exceptions & ~VFP_NAN_FLAG;
}
/*
*/
barrier();
trigger = fmrx(FPINST2);
- fpscr = fmrx(FPSCR);
+ orig_fpscr = fpscr = fmrx(FPSCR);
emulate:
exceptions = vfp_emulate_instruction(trigger, fpscr, regs);
if (exceptions)
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.
*/
static int __init vfp_init(void)
{
unsigned int vfpsid;
+ unsigned int cpu_arch = cpu_architecture();
+ u32 access = 0;
+
+ if (cpu_arch >= CPU_ARCH_ARMv6) {
+ access = get_copro_access();
+
+ /*
+ * Enable full access to VFP (cp10 and cp11)
+ */
+ set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
+ }
/*
* First check that there is a VFP that we can use.
* we just need to read the VFPSID register.
*/
vfpsid = fmrx(FPSID);
+ barrier();
printk(KERN_INFO "VFP support v0.3: ");
if (VFP_arch) {
printk("not present\n");
+
+ /*
+ * Restore the copro access register.
+ */
+ if (cpu_arch >= CPU_ARCH_ARMv6)
+ set_copro_access(access);
} 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,
(vfpsid & FPSID_PART_MASK) >> FPSID_PART_BIT,
(vfpsid & FPSID_VARIANT_MASK) >> FPSID_VARIANT_BIT,
(vfpsid & FPSID_REV_MASK) >> FPSID_REV_BIT);
+
vfp_vector = vfp_support_entry;
+
+ thread_register_notifier(&vfp_notifier_block);
+
+ /*
+ * We detected VFP, and the support code is
+ * in place; report VFP support to userspace.
+ */
+ elf_hwcap |= HWCAP_VFP;
}
return 0;
}
git://git.onelab.eu / linux-2.6.git / blobdiff