ARC: [ASID] Refactor the TLB paranoid debug code

-Asm code already has values of SW and HW ASID values, so they can be
 passed to the printing routine.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/mmu.h

@@ -52,7 +52,7 @@ typedef struct {
 } mm_context_t;
 
 #ifdef CONFIG_ARC_DBG_TLB_PARANOIA
-void tlb_paranoid_check(unsigned int pid_sw, unsigned long address);
+void tlb_paranoid_check(unsigned int mm_asid, unsigned long address);
 #else
 #define tlb_paranoid_check(a, b)
 #endif

arch/arc/mm/tlb.c

@@ -688,25 +688,27 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
  * Low Level ASM TLB handler calls this if it finds that HW and SW ASIDS
  * don't match
  */
-void print_asid_mismatch(int is_fast_path)
+void print_asid_mismatch(int mm_asid, int mmu_asid, int is_fast_path)
 {
-	int pid_sw, pid_hw;
-	pid_sw = current->active_mm->context.asid;
-	pid_hw = read_aux_reg(ARC_REG_PID) & 0xff;
-
 	pr_emerg("ASID Mismatch in %s Path Handler: sw-pid=0x%x hw-pid=0x%x\n",
-	       is_fast_path ? "Fast" : "Slow", pid_sw, pid_hw);
+	       is_fast_path ? "Fast" : "Slow", mm_asid, mmu_asid);
 
 	__asm__ __volatile__("flag 1");
 }
 
-void tlb_paranoid_check(unsigned int pid_sw, unsigned long addr)
+void tlb_paranoid_check(unsigned int mm_asid, unsigned long addr)
 {
-	unsigned int pid_hw;
+	unsigned int mmu_asid;
 
-	pid_hw = read_aux_reg(ARC_REG_PID) & 0xff;
+	mmu_asid = read_aux_reg(ARC_REG_PID) & 0xff;
 
-	if (addr < 0x70000000 && ((pid_hw != pid_sw) || (pid_sw == NO_ASID)))
-		print_asid_mismatch(0);
+	/*
+	 * At the time of a TLB miss/installation
+	 *   - HW version needs to match SW version
+	 *   - SW needs to have a valid ASID
+	 */
+	if (addr < 0x70000000 &&
+	    ((mmu_asid != mm_asid) || (mm_asid == NO_ASID)))
+		print_asid_mismatch(mm_asid, mmu_asid, 0);
 }
 #endif

arch/arc/mm/tlbex.S

@@ -102,7 +102,7 @@ ex_saved_reg1:
 	; VERIFY if the ASID in MMU-PID Reg is same as
 	; one in Linux data structures
 
-	DBG_ASID_MISMATCH
+	tlb_paranoid_check_asm
 .endm
 
 .macro TLBMISS_RESTORE_REGS
@@ -133,31 +133,29 @@ ex_saved_reg1:
 ; In bizzare scenrios SW and HW ASID can get out-of-sync which is trouble.
 ; So we try to detect this in TLB Mis shandler
 
-
-.macro DBG_ASID_MISMATCH
+.macro tlb_paranoid_check_asm
 
 #ifdef CONFIG_ARC_DBG_TLB_PARANOIA
 
-	; make sure h/w ASID is same as s/w ASID
-
 	GET_CURR_TASK_ON_CPU  r3
 	ld r0, [r3, TASK_ACT_MM]
 	ld r0, [r0, MM_CTXT+MM_CTXT_ASID]
 
 	lr r1, [ARC_REG_PID]
 	and r1, r1, 0xFF
+
 	breq r1, r0, 5f
 
 	; Error if H/w and S/w ASID don't match, but NOT if in kernel mode
-	lr  r0, [erstatus]
-	bbit0 r0, STATUS_U_BIT, 5f
+	lr  r2, [erstatus]
+	bbit0 r2, STATUS_U_BIT, 5f
 
 	; We sure are in troubled waters, Flag the error, but to do so
 	; need to switch to kernel mode stack to call error routine
 	GET_TSK_STACK_BASE   r3, sp
 
 	; Call printk to shoutout aloud
-	mov r0, 1
+	mov r2, 1
 	j print_asid_mismatch
 
 5:	; ASIDs match so proceed normally