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io apic question
by bharath.bhushan
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I am looking at 4.9 sources.
When the local apic is mapped into SMPpt in sys/i386/i386/pmap.c:pmap_bootstrap(), it is mapped cache-disabled (PG_N). When the IO apics are being mapped into SMPpt in sys/i386/i386/mp_machdep.c:mptable_pass2(), it is *not* mapped cache-disabled. Why is this difference? In 5.5, I see that ioapic_create() calls pmap_createdev(), which allocates cache-enabled kind of mapping. Am I missing something here? -- Thanks Bharath _______________________________________________ freebsd-ia32@... mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ia32 To unsubscribe, send any mail to "freebsd-ia32-unsubscribe@..." |
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Re: io apic question
by jhb-3
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On Saturday 02 September 2006 02:26, Bharath Bhushan wrote:
> I am looking at 4.9 sources. > > When the local apic is mapped into SMPpt in > sys/i386/i386/pmap.c:pmap_bootstrap(), it is mapped cache-disabled > (PG_N). > > When the IO apics are being mapped into SMPpt in > sys/i386/i386/mp_machdep.c:mptable_pass2(), it is *not* mapped > cache-disabled. > > Why is this difference? Probably a bug. > In 5.5, I see that ioapic_create() calls pmap_createdev(), which > allocates cache-enabled kind of mapping. > > Am I missing something here? In 7.0 we map them cache-disabled now. -- John Baldwin _______________________________________________ freebsd-ia32@... mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ia32 To unsubscribe, send any mail to "freebsd-ia32-unsubscribe@..." |
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Re: io apic question
by bharath.bhushan
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Thanks John.
Can you please point me to the place where cache-disabled mapping is being done in 7.0? I looked at -- ioapic_create -> pmap_mapdev -> pmap_kenter -> pte_store(pte, pa | PG_RW | PG_V | pgeflag); I could not find any references to PG_N in code related to pmap or to IOAPICs. On 9/6/06, John Baldwin <jhb@...> wrote: > On Saturday 02 September 2006 02:26, Bharath Bhushan wrote: > > I am looking at 4.9 sources. > > > > When the local apic is mapped into SMPpt in > > sys/i386/i386/pmap.c:pmap_bootstrap(), it is mapped cache-disabled > > (PG_N). > > > > When the IO apics are being mapped into SMPpt in > > sys/i386/i386/mp_machdep.c:mptable_pass2(), it is *not* mapped > > cache-disabled. > > > > Why is this difference? > > Probably a bug. > > > In 5.5, I see that ioapic_create() calls pmap_createdev(), which > > allocates cache-enabled kind of mapping. > > > > Am I missing something here? > > In 7.0 we map them cache-disabled now. > > -- > John Baldwin > -- Thanks Bharath _______________________________________________ freebsd-ia32@... mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ia32 To unsubscribe, send any mail to "freebsd-ia32-unsubscribe@..." |
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Re: io apic question
by jhb-3
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On Friday 08 September 2006 14:34, Bharath Bhushan wrote:
> Thanks John. > > Can you please point me to the place where cache-disabled mapping is > being done in 7.0? > I looked at -- ioapic_create -> pmap_mapdev -> pmap_kenter -> > pte_store(pte, pa | PG_RW | PG_V | pgeflag); > > I could not find any references to PG_N in code related to pmap or to IOAPICs. In 7.0 pmap_mapdev() calls pmap_mapdev_attr(..., PAT_UNCACHEABLE). > On 9/6/06, John Baldwin <jhb@...> wrote: > > On Saturday 02 September 2006 02:26, Bharath Bhushan wrote: > > > I am looking at 4.9 sources. > > > > > > When the local apic is mapped into SMPpt in > > > sys/i386/i386/pmap.c:pmap_bootstrap(), it is mapped cache-disabled > > > (PG_N). > > > > > > When the IO apics are being mapped into SMPpt in > > > sys/i386/i386/mp_machdep.c:mptable_pass2(), it is *not* mapped > > > cache-disabled. > > > > > > Why is this difference? > > > > Probably a bug. > > > > > In 5.5, I see that ioapic_create() calls pmap_createdev(), which > > > allocates cache-enabled kind of mapping. > > > > > > Am I missing something here? > > > > In 7.0 we map them cache-disabled now. > > > > -- > > John Baldwin > > > > > -- > Thanks > Bharath > -- John Baldwin _______________________________________________ freebsd-ia32@... mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ia32 To unsubscribe, send any mail to "freebsd-ia32-unsubscribe@..." |
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Re: io apic question
by bharath.bhushan
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Thanks a lot.
On 9/9/06, John Baldwin <jhb@...> wrote: > On Friday 08 September 2006 14:34, Bharath Bhushan wrote: > > Thanks John. > > > > Can you please point me to the place where cache-disabled mapping is > > being done in 7.0? > > I looked at -- ioapic_create -> pmap_mapdev -> pmap_kenter -> > > pte_store(pte, pa | PG_RW | PG_V | pgeflag); > > > > I could not find any references to PG_N in code related to pmap or to > IOAPICs. > > In 7.0 pmap_mapdev() calls pmap_mapdev_attr(..., PAT_UNCACHEABLE). > > > On 9/6/06, John Baldwin <jhb@...> wrote: > > > On Saturday 02 September 2006 02:26, Bharath Bhushan wrote: > > > > I am looking at 4.9 sources. > > > > > > > > When the local apic is mapped into SMPpt in > > > > sys/i386/i386/pmap.c:pmap_bootstrap(), it is mapped cache-disabled > > > > (PG_N). > > > > > > > > When the IO apics are being mapped into SMPpt in > > > > sys/i386/i386/mp_machdep.c:mptable_pass2(), it is *not* mapped > > > > cache-disabled. > > > > > > > > Why is this difference? > > > > > > Probably a bug. > > > > > > > In 5.5, I see that ioapic_create() calls pmap_createdev(), which > > > > allocates cache-enabled kind of mapping. > > > > > > > > Am I missing something here? > > > > > > In 7.0 we map them cache-disabled now. > > > > > > -- > > > John Baldwin > > > > > > > > > -- > > Thanks > > Bharath > > > > -- > John Baldwin > -- Thanks Bharath _______________________________________________ freebsd-ia32@... mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ia32 To unsubscribe, send any mail to "freebsd-ia32-unsubscribe@..." |
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