On Thu, May 17, 2001 at 02:23:03PM +0200, Michael Wildpaner wrote:
> 
> trying to boot any 2.4.x kernel on a Tsunami DP264 alpha with dual EV67,
> we found the following problems:
> 
> CPU misdetection:
> 
>       On our machine the cpu->type field contains 0x80000000B
>       (= 2^35 + 11) instead of 0xB (= hwrpb.h: #define EV67_CPU 11).
> 
>       The spurious high bit leads to false/default values for
>       on_chip_cache in smp.c:smp_tune_scheduling.
>...
>+/* mask for cpu->type (arbitrary assumption based on #define's in hwrpb.h) */
>+#define CPU_TYPE_MASK 0xFFFFFF
>...
>-      switch (cpu->type)
>+      switch (cpu->type & CPU_TYPE_MASK)

The Alpha Architecture Reference Manual describes the PROCESSOR TYPE field
of the per-CPU slot HWRPB information, as:

        bits    interpretation
        ----    --------------
        63-32   minor type
        31-0    major type

so the above patch should have CPU_TYPE_MASK as 0xffffffff (optimistic :-);
or you could just:

        switch ((unsigned int) cpu->type)

like the /proc/cpuinfo printing code in setup.c does.

The "minor type" is usually a reference to the "pass" number of the chip,
and can be ignored.

--Jay++

-----------------------------------------------------------------------------
Jay A Estabrook                            Alpha Engineering - LINUX Project
Compaq Computer Corp. - MRO1-2/K20         (508) 467-2080
200 Forest Street, Marlboro MA 01752       [EMAIL PROTECTED]
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