Re: [PATCH 1/10 -tip] x86: Add cpufeature for Processor Name

[Jaswinder Singh Rajput <jaswinder@kernel.org>]

On Wed, 2009-05-20 at 23:11 -0700, H. Peter Anvin wrote:
> Jaswinder Singh Rajput wrote:
> > Processor Name / Brand String (Function 8000_0002h, 8000_0003h, 8000_0004h)
> > Functions 8000_0002h, 8000_0003h, and 8000_0004h each return up to 16 ASCII
> > bytes of the processor name in the EAX, EBX, ECX and EDX registers.
> > 
> > X86_FEATURE_PNAME will be useful for displaying MSRs like AMD:
> > MSRC001_00[35:30] Processor Name String Registers
> > 
> 
> Pointless and wrong.  The presence of the processor name is not the same
> thing as the presence of specific MSRs, which are model-specific.
> 

>From AMD's BIOS and Kernel Developer’s Guide(BKDG) Manual :

 MSRC001_00[35:30] Processor Name String Registers
Reset: 0000 0000 0000 0000h. These registers holds the CPUID name string in ASCII. The state of these regis-
ters are returned by CPUID instructions, CPUID Fn8000_000[4:2]. BIOS should set these registers to the
AMD-provided product name for the processor. Each register contains a block of 8 ASCII characters; the least
byte corresponds to the first ASCII character of the block; the most-significant byte corresponds to the last
character of the block. MSRC001_0030 contains the first block of the name string; MSRC001_0035 contains
the last block of the name string.

  Bits    Description
  63:0 CpuNameString. Read-write.

--
JSR