Messages in this thread | | | Date | Sun, 30 Mar 2008 18:33:04 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH 8/8] x86_64: Support for new UV apic |
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On Sun, Mar 30, 2008 at 4:22 PM, Yinghai Lu <yhlu.kernel@gmail.com> wrote: > > On Fri, Mar 28, 2008 at 12:12 PM, Jack Steiner <steiner@sgi.com> wrote: > > > > UV supports really big systems. So big, in fact, that the APICID register > > does not contain enough bits to contain an APICID that is unique across all > > cpus. > > > > The UV BIOS supports 3 APICID modes: > > > > - legacy mode. This mode uses the old APIC mode where > > APICID is in bits [31:24] of the APICID register. > > > > - x2apic mode. This mode is whitebox-compatible. APICIDs > > are unique across all cpus. Standard x2apic APIC operations > > (Intel-defined) can be used for IPIs. The node identifier > > fits within the Intel-defined portion of the APICID register. > > > > - x2apic-uv mode. In this mode, the APICIDs on each node have > > unique IDs, but IDs on different node are not unique. For example, > > if each mode has 32 cpus, the APICIDs on each node might be > > 0 - 31. Every node has the same set of IDs. > > The UV hub is used to route IPIs/interrupts to the correct node. > > Traditional APIC operations WILL NOT WORK. > > > > In x2apic-uv mode, the ACPI tables all contain a full unique ID (note: > > exact bit layout still changing but the following is close): > > > > nnnnnnnnnnlc0cch > > n = unique node number > > l = socket number on board > > c = core > > h = hyperthread > > > > Only the "lc0cch" bits are written to the APICID register. The remaining bits are > > supplied by having the get_apic_id() function "OR" the extra bits into the value > > read from the APICID register. (Hmmm.. why not keep the ENTIRE APICID register > > in per-cpu data....) > > > > The x2apic-uv mode is recognized by the MADT table containing: > > oem_id = "SGI" > > oem_table_id = "UV-X" > > > > Based on: > > git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git > > > > Signed-off-by: Jack Steiner <steiner@sgi.com> > > > > --- > > arch/x86/kernel/Makefile | 2 > > arch/x86/kernel/apic_64.c | 2 > > arch/x86/kernel/genapic_64.c | 18 ++ > > arch/x86/kernel/genx2apic_uv_x.c | 245 +++++++++++++++++++++++++++++++++++++++ > > arch/x86/kernel/setup64.c | 4 > > arch/x86/kernel/smpboot.c | 5 > > include/asm-x86/genapic_64.h | 5 > > include/asm-x86/smp.h | 5 > > 8 files changed, 285 insertions(+), 1 deletion(-) > > > > Index: linux/arch/x86/kernel/genapic_64.c > > =================================================================== > > --- linux.orig/arch/x86/kernel/genapic_64.c 2008-03-28 13:06:07.000000000 -0500 > > +++ linux/arch/x86/kernel/genapic_64.c 2008-03-28 13:06:12.000000000 -0500 > > @@ -15,6 +15,7 @@ > > #include <linux/kernel.h> > > #include <linux/ctype.h> > > #include <linux/init.h> > > +#include <linux/hardirq.h> > > > > #include <asm/smp.h> > > #include <asm/ipi.h> > > @@ -32,6 +33,7 @@ void *x86_cpu_to_apicid_early_ptr; > > #endif > > DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID; > > EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid); > > +DEFINE_PER_CPU(int, x2apic_extra_bits); > > > > struct genapic __read_mostly *genapic = &apic_flat; > > > > @@ -42,6 +44,9 @@ static enum uv_system_type uv_system_typ > > */ > > void __init setup_apic_routing(void) > > { > > + if (uv_system_type == UV_NON_UNIQUE_APIC) > > + genapic = &apic_x2apic_uv_x; > > + else > > #ifdef CONFIG_ACPI > > /* > > * Quirk: some x86_64 machines can only use physical APIC mode > > @@ -82,6 +87,19 @@ int __init acpi_madt_oem_check(char *oem > > return 0; > > } > > > > +unsigned int read_apic_id(void) > > +{ > > + unsigned int id; > > + > > + WARN_ON(preemptible()); > > + id = apic_read(APIC_ID); > > + if (uv_system_type >= UV_X2APIC) > > + id |= __get_cpu_var(x2apic_extra_bits); > > + else > > + id = (id >> 24) & 0xFFu;; > > + return id; > > +} > > so this is "the new one of Friday"? > > it still wrong. you can not shit id here. ot broke all x86_64 smp. > > Did you test it on non UV_X2APIC box?
anyway the read_apic_id is totally wrong, even for your UV_X2APIC box. because id=apic_read(APIC_ID) will have apic_id at bits [31,24], and id |= __get_cpu_var(x2apic_extra_bits) is assuming that is on bits [5,0]
so you even didn't test in your UV_X2APIC box!
YH
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