Re: [Qemu-devel] [RFC PATCH v2 10/15] cpu-model/s390: Add cpu class initialization routines

Michael Mueller
2015-02-20T18:59:39Z

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On Fri, 20 Feb 2015 10:11:55 -0800
Richard Henderson <rth@twiddle.net> wrote:

> > +static inline uint64_t big_endian_bit(unsigned long nr)
> > +{
> > + return 1ul << (BITS_PER_LONG - (nr % BITS_PER_LONG));
> > +};
>
> This is buggy. NR=0 should map to 63, not 64.

I'm sure I was asked to replace my constant 64 and 63 with that defines and at the end I messed
it up... :-(

>
> > + return !!(*ptr & big_endian_bit(nr));
>
> Personally I dislike !! as an idiom. Given that big_endian_bit isn't used
> anywhere else, can we integrate it and change this to
>
> static inline int test_facility(unsigned long nr, uint64_t *fac_list)
> {
> unsigned long word = nr / BITS_PER_LONG;
> unsigned long be_bit = 63 - (nr % BITS_PER_LONG);
> return (fac_list[word] >> be_bit) & 1;
> }

Yes, I just use it in this context. I will integrate your version.

BTW I changed the whole facility defining code to be generated by an external helper at compile
time. That is more simple and safe to change. I will send it with v3. See attachment for an
example of the generated header file.

Thanks,
Michael

[-- Attachment #2: gen-facilities.h --]
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/*
* AUTOMATICALLY GENERATED, DO NOT MODIFY HERE, EDIT
* SOURCE FILE "target-s390x/tools/gen-facilities.c" INSTEAD.
*
* Copyright 2014, 2015 IBM Corp.
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/

#ifndef TARGET_S390X_GEN_FACILITIES_H
#define TARGET_S390X_GEN_FACILITIES_H

/* S390 CPU facility defines per CPU model */
#define FAC_LIST_CPU_S390_2064_GA1 0xe000000000000000
#define FAC_LIST_CPU_S390_2064_GA2 0xe000800000000000
#define FAC_LIST_CPU_S390_2064_GA3 0xe000800000000000
#define FAC_LIST_CPU_S390_2066_GA1 0xe000800000000000
#define FAC_LIST_CPU_S390_2084_GA1 0xf000f80000000000
#define FAC_LIST_CPU_S390_2084_GA2 0xf800f80000000000
#define FAC_LIST_CPU_S390_2084_GA3 0xfa00fa0000000000
#define FAC_LIST_CPU_S390_2086_GA1 0xfa00fa0000000000
#define FAC_LIST_CPU_S390_2084_GA4 0xfa00fa0000000000
#define FAC_LIST_CPU_S390_2086_GA2 0xfa00fa0000000000
#define FAC_LIST_CPU_S390_2084_GA5 0xfa00fa0800000000
#define FAC_LIST_CPU_S390_2086_GA3 0xfa00fa0800000000
#define FAC_LIST_CPU_S390_2094_GA1 0xfb00ffcb00000000
#define FAC_LIST_CPU_S390_2094_GA2 0xfb40ffdb80600000
#define FAC_LIST_CPU_S390_2094_GA3 0xfb40ffdb80680000
#define FAC_LIST_CPU_S390_2096_GA1 0xfb40ffdb80680000
#define FAC_LIST_CPU_S390_2096_GA2 0xfb40ffdb80680000
#define FAC_LIST_CPU_S390_2097_GA1 0xfbf0fffbf0780000
#define FAC_LIST_CPU_S390_2097_GA2 0xfbf0fffbf0780000,0x5800000000000000
#define FAC_LIST_CPU_S390_2098_GA1 0xfbf0fffbf0780000,0x5800000000000000
#define FAC_LIST_CPU_S390_2097_GA3 0xfbf0fffbf0f80000,0x5800000000000000
#define FAC_LIST_CPU_S390_2098_GA2 0xfbf0fffbf0f80000,0x5800000000000000
#define FAC_LIST_CPU_S390_2817_GA1 0xfbf0fffbfcfe0000,0x1810000000000000
#define FAC_LIST_CPU_S390_2817_GA2 0xfbf6fffbfcff0000,0x381c000000000000
#define FAC_LIST_CPU_S390_2818_GA1 0xfbf6fffbfcff0000,0x381c000000000000
#define FAC_LIST_CPU_S390_2827_GA1 0xfbf6fffbfcfff800,0x3dde000000000000
#define FAC_LIST_CPU_S390_2827_GA2 0xfbf6fffbfcfff800,0x3dde000000000000
#define FAC_LIST_CPU_S390_2828_GA1 0xfbf6fffbfcfff800,0x3dde000000000000
#define FAC_LIST_CPU_S390_2964_GA1 0xfbf6fffbfcfff800,0x3dde000000000000,0x4000000000000000

/* QEMU facility mask defines */
#define FAC_LIST_CPU_S390_MASK_QEMU 0x0000000000000000,0x0580000000000000

/* Maximum size of generated facility list defines */
#define FAC_LIST_CPU_S390_SIZE_UINT64 3

#endif