Date: Sun, 9 Mar 2014 14:24:06 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r262948 - in head/sys/arm: arm include Message-ID: <201403091424.s29EO6UQ083903@svn.freebsd.org>
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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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