Revert "MIPS: Allow ASID size to be determined at boot time."

This reverts commit d532f3d267.

The original commit has several problems:

1) Doesn't work with 64-bit kernels.

2) Calls TLBMISS_HANDLER_SETUP() before the code is generated.

3) Calls TLBMISS_HANDLER_SETUP() twice in per_cpu_trap_init() when
   only one call is needed.

[ralf@linux-mips.org: Also revert the bits of the ASID patch which were
hidden in the KVM merge.]

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: "Steven J. Hill" <Steven.Hill@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5242/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/genex.S

@@ -493,7 +493,7 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	.set	noreorder
 	/* check if TLB contains a entry for EPC */
 	MFC0	k1, CP0_ENTRYHI
-	andi	k1, 0xff	/* ASID_MASK patched at run-time!! */
+	andi	k1, 0xff	/* ASID_MASK */
 	MFC0	k0, CP0_EPC
 	PTR_SRL k0, _PAGE_SHIFT + 1
 	PTR_SLL k0, _PAGE_SHIFT + 1

arch/mips/kernel/smtc.c

@@ -111,7 +111,7 @@ static int vpe0limit;
 static int ipibuffers;
 static int nostlb;
 static int asidmask;
-unsigned int smtc_asid_mask = 0xff;
+unsigned long smtc_asid_mask = 0xff;
 
 static int __init vpe0tcs(char *str)
 {
@@ -1395,7 +1395,7 @@ void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
 	asid = asid_cache(cpu);
 
 	do {
-		if (!ASID_MASK(ASID_INC(asid))) {
+		if (!((asid += ASID_INC) & ASID_MASK) ) {
 			if (cpu_has_vtag_icache)
 				flush_icache_all();
 			/* Traverse all online CPUs (hack requires contiguous range) */
@@ -1414,7 +1414,7 @@ void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
 						mips_ihb();
 					}
 					tcstat = read_tc_c0_tcstatus();
-					smtc_live_asid[tlb][ASID_MASK(tcstat)] |= (asiduse)(0x1 << i);
+					smtc_live_asid[tlb][(tcstat & ASID_MASK)] |= (asiduse)(0x1 << i);
 					if (!prevhalt)
 						write_tc_c0_tchalt(0);
 				}
@@ -1423,7 +1423,7 @@ void smtc_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
 				asid = ASID_FIRST_VERSION;
 			local_flush_tlb_all();	/* start new asid cycle */
 		}
-	} while (smtc_live_asid[tlb][ASID_MASK(asid)]);
+	} while (smtc_live_asid[tlb][(asid & ASID_MASK)]);
 
 	/*
 	 * SMTC shares the TLB within VPEs and possibly across all VPEs.
@@ -1461,7 +1461,7 @@ void smtc_flush_tlb_asid(unsigned long asid)
 		tlb_read();
 		ehb();
 		ehi = read_c0_entryhi();
-		if (ASID_MASK(ehi) == asid) {
+		if ((ehi & ASID_MASK) == asid) {
 		    /*
 		     * Invalidate only entries with specified ASID,
 		     * makiing sure all entries differ.

arch/mips/kernel/traps.c

@@ -1656,7 +1656,6 @@ void __cpuinit per_cpu_trap_init(bool is_boot_cpu)
 	unsigned int cpu = smp_processor_id();
 	unsigned int status_set = ST0_CU0;
 	unsigned int hwrena = cpu_hwrena_impl_bits;
-	unsigned long asid = 0;
 #ifdef CONFIG_MIPS_MT_SMTC
 	int secondaryTC = 0;
 	int bootTC = (cpu == 0);
@@ -1740,9 +1739,8 @@ void __cpuinit per_cpu_trap_init(bool is_boot_cpu)
 	}
 #endif /* CONFIG_MIPS_MT_SMTC */
 
-	asid = ASID_FIRST_VERSION;
-	cpu_data[cpu].asid_cache = asid;
-	TLBMISS_HANDLER_SETUP();
+	if (!cpu_data[cpu].asid_cache)
+		cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
 
 	atomic_inc(&init_mm.mm_count);
 	current->active_mm = &init_mm;