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 <l...@intel.com>
Closes: 
https://lore.kernel.org/oe-kbuild-all/202308151213.qkzpmiyz-...@intel.com/
Signed-off-by: Vineet Gupta <vgu...@kernel.org>
---
 arch/arc/include/asm/arcregs.h | 27 +++++++---
 arch/arc/include/asm/setup.h   |  1 -
 arch/arc/kernel/setup.c        |  4 +-
 arch/arc/mm/tlb.c              | 93 +++++++++++++---------------------
 4 files changed, 58 insertions(+), 67 deletions(-)

diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index 2162023195c5..af00cbe9b850 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -185,6 +185,27 @@ struct bcr_uarch_build_arcv2 {
 #endif
 };
 
+struct bcr_mmu_3 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       unsigned int ver:8, ways:4, sets:4, res:3, sasid:1, pg_sz:4,
+                    u_itlb:4, u_dtlb:4;
+#else
+       unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, sasid:1, res:3, sets:4,
+                    ways:4, ver:8;
+#endif
+};
+
+struct bcr_mmu_4 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+       unsigned int ver:8, sasid:1, sz1:4, sz0:4, res:2, pae:1,
+                    n_ways:2, n_entry:2, n_super:2, u_itlb:3, u_dtlb:3;
+#else
+       /*           DTLB      ITLB      JES        JE         JA      */
+       unsigned int u_dtlb:3, u_itlb:3, n_super:2, n_entry:2, n_ways:2,
+                    pae:1, res:2, sz0:4, sz1:4, sasid:1, ver:8;
+#endif
+};
+
 struct bcr_mpy {
 #ifdef CONFIG_CPU_BIG_ENDIAN
        unsigned int pad:8, x1616:8, dsp:4, cycles:2, type:2, ver:8;
@@ -307,11 +328,6 @@ struct bcr_generic {
  * Generic structures to hold build configuration used at runtime
  */
 
-struct cpuinfo_arc_mmu {
-       unsigned int ver:4, pg_sz_k:8, s_pg_sz_m:8, pad:10, sasid:1, pae:1;
-       unsigned int sets:12, ways:4, u_dtlb:8, u_itlb:8;
-};
-
 struct cpuinfo_arc_cache {
        unsigned int sz_k:14, line_len:8, assoc:4, alias:1, vipt:1, pad:4;
 };
@@ -326,7 +342,6 @@ struct cpuinfo_arc_ccm {
 
 struct cpuinfo_arc {
        struct cpuinfo_arc_cache icache, dcache, slc;
-       struct cpuinfo_arc_mmu mmu;
        struct cpuinfo_arc_bpu bpu;
        struct bcr_identity core;
        struct bcr_isa_arcv2 isa;
diff --git a/arch/arc/include/asm/setup.h b/arch/arc/include/asm/setup.h
index 374138832c5a..76443f198778 100644
--- a/arch/arc/include/asm/setup.h
+++ b/arch/arc/include/asm/setup.h
@@ -36,7 +36,6 @@ long __init arc_get_mem_sz(void);
 
 extern void arc_mmu_init(void);
 extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
-extern void read_decode_mmu_bcr(void);
 
 extern void arc_cache_init(void);
 extern char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len);
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();
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 2a3105a682c3..861cabe81e87 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -18,7 +18,9 @@
 /* A copy of the ASID from the PID reg is kept in asid_cache */
 DEFINE_PER_CPU(unsigned int, asid_cache) = MM_CTXT_FIRST_CYCLE;
 
-static int __read_mostly pae_exists;
+static struct cpuinfo_arc_mmu {
+       unsigned int ver, pg_sz_k, s_pg_sz_m, pae, sets, ways;
+} mmuinfo;
 
 /*
  * Utility Routine to erase a J-TLB entry
@@ -131,7 +133,7 @@ static void tlb_entry_insert(unsigned int pd0, phys_addr_t 
pd1)
 
 noinline void local_flush_tlb_all(void)
 {
-       struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+       struct cpuinfo_arc_mmu *mmu = &mmuinfo;
        unsigned long flags;
        unsigned int entry;
        int num_tlb = mmu->sets * mmu->ways;
@@ -560,89 +562,64 @@ void local_flush_pmd_tlb_range(struct vm_area_struct 
*vma, unsigned long start,
  * the cpuinfo structure for later use.
  * No Validation is done here, simply read/convert the BCRs
  */
-void read_decode_mmu_bcr(void)
+char *arc_mmu_mumbojumbo(int c, char *buf, int len)
 {
-       struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
-       unsigned int tmp;
-       struct bcr_mmu_3 {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-       unsigned int ver:8, ways:4, sets:4, res:3, sasid:1, pg_sz:4,
-                    u_itlb:4, u_dtlb:4;
-#else
-       unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, sasid:1, res:3, sets:4,
-                    ways:4, ver:8;
-#endif
-       } *mmu3;
-
-       struct bcr_mmu_4 {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-       unsigned int ver:8, sasid:1, sz1:4, sz0:4, res:2, pae:1,
-                    n_ways:2, n_entry:2, n_super:2, u_itlb:3, u_dtlb:3;
-#else
-       /*           DTLB      ITLB      JES        JE         JA      */
-       unsigned int u_dtlb:3, u_itlb:3, n_super:2, n_entry:2, n_ways:2,
-                    pae:1, res:2, sz0:4, sz1:4, sasid:1, ver:8;
-#endif
-       } *mmu4;
+       struct cpuinfo_arc_mmu *mmu = &mmuinfo;
+       unsigned int bcr, u_dtlb, u_itlb, sasid;
+       struct bcr_mmu_3 *mmu3;
+       struct bcr_mmu_4 *mmu4;
+       char super_pg[64] = "";
+       int n = 0;
 
-       tmp = read_aux_reg(ARC_REG_MMU_BCR);
-       mmu->ver = (tmp >> 24);
+       bcr = read_aux_reg(ARC_REG_MMU_BCR);
+       mmu->ver = (bcr >> 24);
 
        if (is_isa_arcompact() && mmu->ver == 3) {
-               mmu3 = (struct bcr_mmu_3 *)&tmp;
+               mmu3 = (struct bcr_mmu_3 *)&bcr;
                mmu->pg_sz_k = 1 << (mmu3->pg_sz - 1);
                mmu->sets = 1 << mmu3->sets;
                mmu->ways = 1 << mmu3->ways;
-               mmu->u_dtlb = mmu3->u_dtlb;
-               mmu->u_itlb = mmu3->u_itlb;
-               mmu->sasid = mmu3->sasid;
+               u_dtlb = mmu3->u_dtlb;
+               u_itlb = mmu3->u_itlb;
+               sasid = mmu3->sasid;
        } else {
-               mmu4 = (struct bcr_mmu_4 *)&tmp;
+               mmu4 = (struct bcr_mmu_4 *)&bcr;
                mmu->pg_sz_k = 1 << (mmu4->sz0 - 1);
                mmu->s_pg_sz_m = 1 << (mmu4->sz1 - 11);
                mmu->sets = 64 << mmu4->n_entry;
                mmu->ways = mmu4->n_ways * 2;
-               mmu->u_dtlb = mmu4->u_dtlb * 4;
-               mmu->u_itlb = mmu4->u_itlb * 4;
-               mmu->sasid = mmu4->sasid;
-               pae_exists = mmu->pae = mmu4->pae;
+               u_dtlb = mmu4->u_dtlb * 4;
+               u_itlb = mmu4->u_itlb * 4;
+               sasid = mmu4->sasid;
+               mmu->pae = mmu4->pae;
        }
-}
 
-char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len)
-{
-       int n = 0;
-       struct cpuinfo_arc_mmu *p_mmu = &cpuinfo_arc700[cpu_id].mmu;
-       char super_pg[64] = "";
-
-       if (p_mmu->s_pg_sz_m)
-               scnprintf(super_pg, 64, "%dM Super Page %s",
-                         p_mmu->s_pg_sz_m,
-                         IS_USED_CFG(CONFIG_TRANSPARENT_HUGEPAGE));
+       if (mmu->s_pg_sz_m)
+               scnprintf(super_pg, 64, "/%dM%s",
+                         mmu->s_pg_sz_m,
+                         IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) ? " (THP 
enabled)":"");
 
        n += scnprintf(buf + n, len - n,
-                     "MMU [v%x]\t: %dk PAGE, %s, swalk %d lvl, JTLB %d 
(%dx%d), uDTLB %d, uITLB %d%s%s\n",
-                      p_mmu->ver, p_mmu->pg_sz_k, super_pg,  
CONFIG_PGTABLE_LEVELS,
-                      p_mmu->sets * p_mmu->ways, p_mmu->sets, p_mmu->ways,
-                      p_mmu->u_dtlb, p_mmu->u_itlb,
-                      IS_AVAIL2(p_mmu->pae, ", PAE40 ", CONFIG_ARC_HAS_PAE40));
+                     "MMU [v%x]\t: %dk%s, swalk %d lvl, JTLB %dx%d, uDTLB %d, 
uITLB %d%s%s%s\n",
+                      mmu->ver, mmu->pg_sz_k, super_pg, CONFIG_PGTABLE_LEVELS,
+                      mmu->sets, mmu->ways,
+                      u_dtlb, u_itlb,
+                      IS_AVAIL1(sasid, ", SASID"),
+                      IS_AVAIL2(mmu->pae, ", PAE40 ", CONFIG_ARC_HAS_PAE40));
 
        return buf;
 }
 
 int pae40_exist_but_not_enab(void)
 {
-       return pae_exists && !is_pae40_enabled();
+       return mmuinfo.pae && !is_pae40_enabled();
 }
 
 void arc_mmu_init(void)
 {
-       struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
-       char str[256];
+       struct cpuinfo_arc_mmu *mmu = &mmuinfo;
        int compat = 0;
 
-       pr_info("%s", arc_mmu_mumbojumbo(0, str, sizeof(str)));
-
        /*
         * Can't be done in processor.h due to header include dependencies
         */
@@ -719,7 +696,7 @@ volatile int dup_pd_silent; /* Be silent abt it or complain 
(default) */
 void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
                          struct pt_regs *regs)
 {
-       struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+       struct cpuinfo_arc_mmu *mmu = &mmuinfo;
        unsigned long flags;
        int set, n_ways = mmu->ways;
 
-- 
2.34.1


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