ARC: boot log: eliminate struct cpuinfo_arc #1: mm

This is first step in eliminating struct cpuinfo_arc[NR_CPUS]

Back when we had just ARCompact ISA, the idea was to read/bit-fiddle
the BCRs once and and cache decoded information in a global struct ready
to use.

With ARCv2 it was modified to contained abstract / ISA agnostic
information.

However with ARCv3 there 's too much disparity to abstract in common
structures. So drop the entire decode once and store paradigm. Afterall
there's only 2 users of this machinery anyways:  boot printing and
cat /proc/cpuinfo. None is performance critical to warrant locking away
resident memory per cpu.

This patch is first step in that direction
 - decouples struct cpuinfo_arc_mmu from global struct cpuinfo_arc
 - mmu code still has a trimmed down static version of
   struct cpuinfo_arc_mmu to cache information needed in performance
   critical code such as tlb flush routines
 - folds read_decode_mmu_bcr() into arc_mmu_mumbojumbo()
 - setup_processor() directly calls arc_mmu_init() and not via
   arc_cpu_init()

Tested-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308151213.qKZPMiyz-lkp@intel.com/
Signed-off-by: Vineet Gupta <vgupta@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 41f07b3e594e..094461540f8a 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -186,7 +186,6 @@ static void read_arc_build_cfg_regs(void)
 	/* Read CCM BCRs for boot reporting even if not enabled in Kconfig */
 	read_decode_ccm_bcr(cpu);
 
-	read_decode_mmu_bcr();
 	read_decode_cache_bcr();
 
 	if (is_isa_arcompact()) {
@@ -256,7 +255,7 @@ static void read_arc_build_cfg_regs(void)
 		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))
+		if (unlikely(cpu->core.family < 0x34))
 			cpu->name = "ARC750";
 	} else {
 		cpu->isa = isa;
@@ -463,6 +462,7 @@ void setup_processor(void)
 	arc_init_IRQ();
 
 	pr_info("%s", arc_cpu_mumbojumbo(cpu_id, str, sizeof(str)));
+	pr_info("%s", arc_mmu_mumbojumbo(cpu_id, str, sizeof(str)));
 
 	arc_mmu_init();
 	arc_cache_init();