Author: ian
Date: Sun Mar 9 14:24:05 2014
New Revision: 262948
URL: http://svnweb.freebsd.org/changeset/base/262948
Log:
Always call vfp_discard() on thread death, not just when the VFP is
enabled. In vfp_discard(), if the state in the VFP hardware belongs to
the thread which is dying, NULL out pcpu fpcurthread to indicate the
state currently in the hardware belongs to nobody.
Submitted by: Juergen Weiss
Pointy hat to: me
Modified:
head/sys/arm/arm/swtch.S
head/sys/arm/arm/vfp.c
head/sys/arm/include/vfp.h
Modified: head/sys/arm/arm/swtch.S
==============================================================================
--- head/sys/arm/arm/swtch.S Sun Mar 9 13:23:49 2014 (r262947)
+++ head/sys/arm/arm/swtch.S Sun Mar 9 14:24:05 2014 (r262948)
@@ -124,14 +124,11 @@ ENTRY(cpu_throw)
* r5 = newtd
*/
- GET_PCPU(r7, r9)
-
-#ifdef VFP
- fmrx r0, fpexc /* This thread is dying, if the VFP */
- tst r0, #(VFPEXC_EN) /* is enabled, go shut it down */
- blne _C_LABEL(vfp_discard) /* without preserving its state. */
+#ifdef VFP /* This thread is dying, disable */
+ bl _C_LABEL(vfp_discard) /* VFP without preserving state. */
#endif
+ GET_PCPU(r7, r9)
ldr r7, [r5, #(TD_PCB)] /* r7 = new thread's PCB */
/* Switch to lwp0 context */
Modified: head/sys/arm/arm/vfp.c
==============================================================================
--- head/sys/arm/arm/vfp.c Sun Mar 9 13:23:49 2014 (r262947)
+++ head/sys/arm/arm/vfp.c Sun Mar 9 14:24:05 2014 (r262948)
@@ -229,21 +229,23 @@ vfp_store(struct vfp_state *vfpsave, boo
}
/*
- * If the VFP hardware is on, the current thread was using it but now that
- * thread is dying. Turn off the VFP and set pcpu fpcurthread to 0, to
indicate
- * that the VFP hardware state does not belong to any thread. Called only
from
- * cpu_throw(), so we don't have to worry about a context switch here.
+ * The current thread is dying. If the state currently in the hardware belongs
+ * to the current thread, set fpcurthread to NULL to indicate that the VFP
+ * hardware state does not belong to any thread. If the VFP is on, turn it
off.
+ * Called only from cpu_throw(), so we don't have to worry about a context
+ * switch here.
*/
void
-vfp_discard()
+vfp_discard(struct thread *td)
{
u_int tmp;
+ if (PCPU_GET(fpcurthread) == td)
+ PCPU_SET(fpcurthread, NULL);
+
tmp = fmrx(VFPEXC);
- if (tmp & VFPEXC_EN) {
+ if (tmp & VFPEXC_EN)
fmxr(VFPEXC, tmp & ~VFPEXC_EN);
- PCPU_SET(fpcurthread, 0);
- }
}
#endif
Modified: head/sys/arm/include/vfp.h
==============================================================================
--- head/sys/arm/include/vfp.h Sun Mar 9 13:23:49 2014 (r262947)
+++ head/sys/arm/include/vfp.h Sun Mar 9 14:24:05 2014 (r262948)
@@ -129,7 +129,7 @@
#ifndef LOCORE
void vfp_init(void);
void vfp_store(struct vfp_state *, boolean_t);
-void vfp_discard(void);
+void vfp_discard(struct thread *);
#endif
#endif
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