Messages in this thread Patch in this message | | | Date | Mon, 15 Sep 2008 18:02:55 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH] x86: smpboot - check if we have ESR register in wakeup_secondary_cpu |
| |
[Ingo Molnar - Mon, Sep 15, 2008 at 09:56:55AM +0200] | | * Cyrill Gorcunov <gorcunov@gmail.com> wrote: | | > We should check if we have ESR register before writting to it. | > | > Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> | > --- | > | > Please review! | > it seems the same nit in do_boot_cpu - checking now. | > | > Index: linux-2.6.git/arch/x86/kernel/smpboot.c | > =================================================================== | > --- linux-2.6.git.orig/arch/x86/kernel/smpboot.c 2008-09-14 19:43:03.000000000 +0400 | > +++ linux-2.6.git/arch/x86/kernel/smpboot.c 2008-09-14 21:49:36.000000000 +0400 | > @@ -598,10 +598,12 @@ wakeup_secondary_cpu(int logical_apicid, | > * Give the other CPU some time to accept the IPI. | > */ | > udelay(200); | > - maxlvt = lapic_get_maxlvt(); | > - if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ | > - apic_write(APIC_ESR, 0); | > - accept_status = (apic_read(APIC_ESR) & 0xEF); | > + if (APIC_INTEGRATED(apic_version[phys_apicid])) { | > + maxlvt = lapic_get_maxlvt(); | > + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ | > + apic_write(APIC_ESR, 0); | > + accept_status = (apic_read(APIC_ESR) & 0xEF); | > + } | > pr_debug("NMI sent.\n"); | | hm, is there any non-integrated lapic that has more than 3 lvts? iirc | lvts were introduced with the integrated lapic. | | Ingo |
Ingo, here is an updated version of patch - only subject and patch message updated (not patch body)
- Cyrill - --- From: Cyrill Gorcunov <gorcunov@gmail.com> Subject: x86: wakeup_secondary_cpu - check if we have ESR register to read
We shouldn't read ESR register on discrete APIC. Check it first.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> ---
Index: linux-2.6.git/arch/x86/kernel/smpboot.c =================================================================== --- linux-2.6.git.orig/arch/x86/kernel/smpboot.c 2008-09-14 19:43:03.000000000 +0400 +++ linux-2.6.git/arch/x86/kernel/smpboot.c 2008-09-14 21:49:36.000000000 +0400 @@ -598,10 +598,12 @@ wakeup_secondary_cpu(int logical_apicid, * Give the other CPU some time to accept the IPI. */ udelay(200); - maxlvt = lapic_get_maxlvt(); - if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ - apic_write(APIC_ESR, 0); - accept_status = (apic_read(APIC_ESR) & 0xEF); + if (APIC_INTEGRATED(apic_version[phys_apicid])) { + maxlvt = lapic_get_maxlvt(); + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ + apic_write(APIC_ESR, 0); + accept_status = (apic_read(APIC_ESR) & 0xEF); + } pr_debug("NMI sent.\n"); if (send_status)
| |