[PATCH v2] ARM: advertise availability of v8 Crypto instructions

[Russell King - ARM Linux]

On Mon, Mar 09, 2015 at 07:38:01PM +0100, Ard Biesheuvel wrote:
> Replying to self: looking at the arm64 code, it seems the 4-bit block
> are signed quantities, and the negative valiues are reserved.
> This means only signed higher values should be considered incremental,
> and values with bit 4 set should be ignored.

ITYM bit 3.

On 32-bit, we've assumed that they're unsigned:

        /* LPAE implies atomic ldrd/strd instructions */
        vmsa = (read_cpuid_ext(CPUID_EXT_MMFR0) & 0xf) >> 0;
        if (vmsa >= 5)
                elf_hwcap |= HWCAP_LPAE;

        sync_prim = ((read_cpuid_ext(CPUID_EXT_ISAR3) >> 8) & 0xf0) |
                    ((read_cpuid_ext(CPUID_EXT_ISAR4) >> 20) & 0x0f);
        if (sync_prim >= 0x13)
                elf_hwcap &= ~HWCAP_SWP;

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