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| author | Eugeniy Paltsev <eugeniy.paltsev@synopsys.com> | 2019-01-30 19:32:41 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2019-02-25 12:10:58 -0800 |
| commit | 76551468833cd5c356b1d9ff4bc9393fcf768a59 (patch) | |
| tree | 8e2552cc13389bc3c90c916b0342bfac7f3a90b1 /arch/arc/kernel/setup.c | |
| parent | 4d1e7918aae59ef504f5170a4f0c7ae82339fcb2 (diff) | |
| download | linux-76551468833cd5c356b1d9ff4bc9393fcf768a59.tar.bz2 | |
ARCv2: Add explcit unaligned access support (and ability to disable too)
As of today we enable unaligned access unconditionally on ARCv2.
Do this under a Kconfig option to allow disable it for test, benchmarking
etc. Also while at it
- Select HAVE_EFFICIENT_UNALIGNED_ACCESS
- Although gcc defaults to unaligned access (since GNU 2018.03), add the
right toggles for enabling or disabling as appropriate
- update bootlog to prints both HW feature status (exists, enabled/disabled)
and SW status (used / not used).
- wire up the relaxed memcpy for unaligned access
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: squashed patches, handle gcc -mno-unaligned-access quick]
Diffstat (limited to 'arch/arc/kernel/setup.c')
| -rw-r--r-- | arch/arc/kernel/setup.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index 7b2340996cf8..2266e4ee4142 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -263,7 +263,7 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len) { struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id]; struct bcr_identity *core = &cpu->core; - int i, n = 0, ua = 0; + int n = 0; FIX_PTR(cpu); @@ -283,16 +283,23 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len) IS_AVAIL2(cpu->extn.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT), IS_AVAIL2(cpu->extn.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT)); -#ifdef __ARC_UNALIGNED__ - ua = 1; + n += scnprintf(buf + n, len - n, "%s%s%s%s%s%s", + IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC), + IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64), + IS_AVAIL2(cpu->isa.unalign, "unalign ", CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS)); + +#if defined(__ARC_UNALIGNED__) && !defined(CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS) + /* + * gcc 7.3.1 (GNU 2018.03) onwards generate unaligned access by default + * but -mno-unaligned-access to disable that didn't work until gcc 8.2.1 + * (GNU 2019.03). So landing here implies the interim period, when + * despite Kconfig being off, gcc is generating unaligned accesses which + * could bomb later on. So better to disallow such broken builds + */ + BUILD_BUG_ON_MSG(1, "gcc doesn't support -mno-unaligned-access"); #endif - n += i = scnprintf(buf + n, len - n, "%s%s%s%s%s%s", - IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC), - IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64), - IS_AVAIL1(cpu->isa.unalign, "unalign "), IS_USED_RUN(ua)); - if (i) - n += scnprintf(buf + n, len - n, "\n\t\t: "); + n += scnprintf(buf + n, len - n, "\n\t\t: "); if (cpu->extn_mpy.ver) { if (cpu->extn_mpy.ver <= 0x2) { /* ARCompact */ |