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authorVineet Gupta <vgupta@synopsys.com>2017-09-21 17:46:38 -0700
committerVineet Gupta <vgupta@synopsys.com>2017-10-03 20:36:49 -0700
commit010a8c98884f4ca42a167c9b51470c624daa2932 (patch)
tree7ad8780e807cf953be4d31055394655b3b06868a /arch/arc/kernel/setup.c
parentarc: remove redundant UTS_MACHINE define in arch/arc/Makefile (diff)
downloadlinux-dev-010a8c98884f4ca42a167c9b51470c624daa2932.tar.xz
linux-dev-010a8c98884f4ca42a167c9b51470c624daa2932.zip
ARC: boot log: decontaminate ARCv2 ISA_CONFIG register
ARCv2 ISA_CONFIG and ARC700_BUILD build config registers are not compatible. cpuinfo_arc had isa info placeholder which was mashup of bits form both. Untangle this by defining it off of ARCv2 ISA info and it is fine even for ARC700 since former is a super set of latter (ARC700 buildonly has 2 bits for atomics and stack check). At runtime, we treat ARCv2 ISA info as a generic placeholder but populate it correctly depending on ARC700 or HS. This paves way for adding more HS specific bits in isa info which was colliding with the extra bits for arc700. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to '')
-rw-r--r--arch/arc/kernel/setup.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 877cec8f5ea2..228593a964f8 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -119,11 +119,11 @@ static void read_arc_build_cfg_regs(void)
struct bcr_generic bcr;
struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
const struct id_to_str *tbl;
+ struct bcr_isa_arcv2 isa;
FIX_PTR(cpu);
READ_BCR(AUX_IDENTITY, cpu->core);
- READ_BCR(ARC_REG_ISA_CFG_BCR, cpu->isa);
for (tbl = &arc_cpu_rel[0]; tbl->id != 0; tbl++) {
if (cpu->core.family == tbl->id) {
@@ -205,18 +205,25 @@ static void read_arc_build_cfg_regs(void)
cpu->extn.debug = cpu->extn.ap | cpu->extn.smart | cpu->extn.rtt;
+ READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
+
/* some hacks for lack of feature BCR info in old ARC700 cores */
if (is_isa_arcompact()) {
- if (!cpu->isa.ver) /* ISA BCR absent, use Kconfig info */
+ if (!isa.ver) /* ISA BCR absent, use Kconfig info */
cpu->isa.atomic = IS_ENABLED(CONFIG_ARC_HAS_LLSC);
- else
- cpu->isa.atomic = cpu->isa.atomic1;
+ else {
+ /* ARC700_BUILD only has 2 bits of isa info */
+ struct bcr_generic bcr = *(struct bcr_generic *)&isa;
+ cpu->isa.atomic = bcr.info & 1;
+ }
cpu->isa.be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
/* there's no direct way to distinguish 750 vs. 770 */
if (unlikely(cpu->core.family < 0x34 || cpu->mmu.ver < 3))
cpu->name = "ARC750";
+ } else {
+ cpu->isa = isa;
}
}