Re: [PATCH] [RFC][V3] bluegene: add entry to cpu table

From: Benjamin Herrenschmidt
Date: Tue Jun 07 2011 - 20:49:54 EST


On Tue, 2011-06-07 at 13:47 -0500, Eric Van Hensbergen wrote:
> Create an entry for the BG/P chips, include bits to accomodate
> the double fp2 fpu and the special MMU considerations like L1
> writethrough.
>
> RFC Note: this patch fails scripts/checkpatch.pl because I
> matched coding style of the surrounding existing code. Would
> you rather have something checkpatch.pl clean or something
> which is consistent with the surrounding code style?

Stay consistent. You're welcome to my next checkpatch burning
ceremony :-)

> The three I got were:
> ERROR: Macros with complex values should be enclosed in parenthesis
> ERROR: "foo* bar" should be "foo *bar"
> WARNING: externs should be avoided in .c files
> and I got these by copying other code as an example.
>
> Thanks for any feedback.
>
> Signed-off-by: Eric Van Hensbergen <ericvh@xxxxxxxxx>
> ---
> arch/powerpc/include/asm/cputable.h | 1 +
> arch/powerpc/include/asm/mmu.h | 9 +++++++++
> arch/powerpc/kernel/cpu_setup_44x.S | 1 +
> arch/powerpc/kernel/cputable.c | 16 ++++++++++++++++
> 4 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index c0d842c..ce709b5 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -26,6 +26,7 @@
> #define PPC_FEATURE_POWER6_EXT 0x00000200
> #define PPC_FEATURE_ARCH_2_06 0x00000100
> #define PPC_FEATURE_HAS_VSX 0x00000080
> +#define PPC_FEATURE_HAS_FPU_FP2 0x00000040

Any chance for a better name ?

> #define PPC_FEATURE_PSERIES_PERFMON_COMPAT \
> 0x00000040
> diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
> index 4138b21..97f9502 100644
> --- a/arch/powerpc/include/asm/mmu.h
> +++ b/arch/powerpc/include/asm/mmu.h
> @@ -56,6 +56,13 @@
> */
> #define MMU_FTR_NEED_DTLB_SW_LRU ASM_CONST(0x00200000)
>
> +/* This indicates that the processor must using writethrough with
> + * the L1 in order to maintain SMP coherence on systems like the
> + * IBM BlueGene/L and IBM BlueGene/P.
> + */
> +
> +#define MMU_FTR_NEED_L1_WRITETHROUGH ASM_CONST(0x00400000)
> +
> /* Enable use of TLB reservation. Processor should support tlbsrx.
> * instruction and MAS0[WQ].
> */
> @@ -112,6 +119,8 @@
> MMU_FTR_USE_PAIRED_MAS | \
> MMU_FTR_TLBIEL | \
> MMU_FTR_16M_PAGE
> +#define MMU_FTRS_BGP MMU_FTR_TYPE_44x | MMU_FTR_16M_PAGE | \
> + MMU_FTR_NEED_L1_WRITETHROUGH

Time to add the ALWAYS/NEVER trick to mmu features like CPU feature has

> #ifndef __ASSEMBLY__
> #include <asm/cputable.h>
>
> diff --git a/arch/powerpc/kernel/cpu_setup_44x.S b/arch/powerpc/kernel/cpu_setup_44x.S
> index e32b4a9..920aed6 100644
> --- a/arch/powerpc/kernel/cpu_setup_44x.S
> +++ b/arch/powerpc/kernel/cpu_setup_44x.S
> @@ -35,6 +35,7 @@ _GLOBAL(__setup_cpu_440grx)
> _GLOBAL(__setup_cpu_460ex)
> _GLOBAL(__setup_cpu_460gt)
> _GLOBAL(__setup_cpu_460sx)
> +_GLOBAL(__setup_cpu_bgp)
> _GLOBAL(__setup_cpu_apm821xx)
> mflr r4
> bl __init_fpu_44x
> diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
> index 34d2722..550a078 100644
> --- a/arch/powerpc/kernel/cputable.c
> +++ b/arch/powerpc/kernel/cputable.c
> @@ -57,6 +57,7 @@ extern void __setup_cpu_750fx(unsigned long offset, struct cpu_spec* spec);
> extern void __setup_cpu_7400(unsigned long offset, struct cpu_spec* spec);
> extern void __setup_cpu_7410(unsigned long offset, struct cpu_spec* spec);
> extern void __setup_cpu_745x(unsigned long offset, struct cpu_spec* spec);
> +extern void __setup_cpu_bgp(unsigned long offset, struct cpu_spec* spec);
> #endif /* CONFIG_PPC32 */
> #ifdef CONFIG_PPC64
> extern void __setup_cpu_ppc970(unsigned long offset, struct cpu_spec* spec);
> @@ -1737,6 +1738,21 @@ static struct cpu_spec __initdata cpu_specs[] = {
> .machine_check = machine_check_440A,
> .platform = "ppc440",
> },
> + { /* Blue Gene/P */
> + .pvr_mask = 0xfffffff0,
> + .pvr_value = 0x52131880,
> + .cpu_name = "450 Blue Gene/P",
> + .cpu_features = CPU_FTRS_440x6,
> + .cpu_user_features = COMMON_USER_BOOKE |
> + PPC_FEATURE_HAS_FPU |
> + PPC_FEATURE_HAS_FPU_FP2,
> + .mmu_features = MMU_FTRS_BGP,
> + .icache_bsize = 32,
> + .dcache_bsize = 32,
> + .cpu_setup = __setup_cpu_bgp,
> + .machine_check = machine_check_440A,
> + .platform = "ppc440",
> + },
> { /* 460EX */
> .pvr_mask = 0xffff0006,
> .pvr_value = 0x13020002,

Cheers,
Ben.

> --
> 1.7.4.1
>
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