Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...

arch/arc/kernel/troubleshoot.c

@@ -117,23 +117,22 @@ static void show_faulting_vma(unsigned long address, char *buf)
 
 static void show_ecr_verbose(struct pt_regs *regs)
 {
-	unsigned int vec, cause_code, cause_reg;
+	unsigned int vec, cause_code;
 	unsigned long address;
 
-	cause_reg = current->thread.cause_code;
-	pr_info("\n[ECR   ]: 0x%08x => ", cause_reg);
+	pr_info("\n[ECR   ]: 0x%08lx => ", regs->event);
 
 	/* For Data fault, this is data address not instruction addr */
 	address = current->thread.fault_address;
 
-	vec = cause_reg >> 16;
-	cause_code = (cause_reg >> 8) & 0xFF;
+	vec = regs->ecr_vec;
+	cause_code = regs->ecr_cause;
 
 	/* For DTLB Miss or ProtV, display the memory involved too */
 	if (vec == ECR_V_DTLB_MISS) {
-		pr_cont("Invalid %s 0x%08lx by insn @ 0x%08lx\n",
-		       (cause_code == 0x01) ? "Read From" :
-		       ((cause_code == 0x02) ? "Write to" : "EX"),
+		pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
+		       (cause_code == 0x01) ? "Read" :
+		       ((cause_code == 0x02) ? "Write" : "EX"),
 		       address, regs->ret);
 	} else if (vec == ECR_V_ITLB_MISS) {
 		pr_cont("Insn could not be fetched\n");
@@ -144,14 +143,12 @@ static void show_ecr_verbose(struct pt_regs *regs)
 	} else if (vec == ECR_V_PROTV) {
 		if (cause_code == ECR_C_PROTV_INST_FETCH)
 			pr_cont("Execute from Non-exec Page\n");
-		else if (cause_code == ECR_C_PROTV_LOAD)
-			pr_cont("Read from Non-readable Page\n");
-		else if (cause_code == ECR_C_PROTV_STORE)
-			pr_cont("Write to Non-writable Page\n");
-		else if (cause_code == ECR_C_PROTV_XCHG)
-			pr_cont("Data exchange protection violation\n");
 		else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
 			pr_cont("Misaligned r/w from 0x%08lx\n", address);
+		else
+			pr_cont("%s access not allowed on page\n",
+				(cause_code == 0x01) ? "Read" :
+				((cause_code == 0x02) ? "Write" : "EX"));
 	} else if (vec == ECR_V_INSN_ERR) {
 		pr_cont("Illegal Insn\n");
 	} else {
@@ -176,8 +173,7 @@ void show_regs(struct pt_regs *regs)
 	print_task_path_n_nm(tsk, buf);
 	show_regs_print_info(KERN_INFO);
 
-	if (current->thread.cause_code)
-		show_ecr_verbose(regs);
+	show_ecr_verbose(regs);
 
 	pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
 		current->thread.fault_address,
@@ -213,10 +209,9 @@ void show_regs(struct pt_regs *regs)
 }
 
 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
-			    unsigned long address, unsigned long cause_reg)
+			    unsigned long address)
 {
 	current->thread.fault_address = address;
-	current->thread.cause_code = cause_reg;
 
 	/* Caller and Callee regs */
 	show_regs(regs);