ARC fixes for 3.16

Some SMP changes, a ptrace request for NPTL debugging,
 bunch of build breakages/warnings
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.14 (GNU/Linux)
 
 iQIcBAABAgAGBQJTrWA6AAoJEGnX8d3iisJeQBoP/jZNSOnuzmOthsVTT9e5F6N5
 57mt+KM2QWIrBXYTTMXw6TcgSFt52gGgvvUAcYNXrgWq1aOT3VcVk9KJFxgsrDhi
 wLOaU4lNVTCgU0riQKofLThWgZYUcZWRxbngEQ2CX1cauIjHH7Cxdt9x5tFFsuaP
 xvPP3zrkpStq05v4ZwGsIMguK8SHTNFHJKFDAEqJk8t1iTIz0yIoMWvArlDeWE4A
 7ackSRzvdNmfirnJCl+bVbhDFiQ2hCdrtgfQG5sVQaI3XPVib/RvW9dDJ99XEzal
 2iBXfjBe15UvzHt+ZBn47cgJpghfCVGfyH0EgeP0jhxilrdQSZw59px0GhpuUIh2
 Avf7cNqhgy+YwOSjW2y0Glyh3dih61wbY7Cajo3W6uTomLFrgE4cq5oNF+8yGbbF
 ez9A11Mnbij7y0ajBg4+5acTd22gEKc5MunbRiIWSSbBtDCVgpIvZoDsewRW/nPY
 lBd50yXxBShIQ/OpvnhBg1zSsQwv5IWXH7QwpWPMcZHfMOiRcCdE3r/jAjLSF2H5
 hk4l+DwkbIdA2qBBQ3kHCxCMcVTRm08aaqdR459SXhzYB6gooDzWqiIXcmFkfXpr
 6nI4muqjQAvIe8JBgKsZmvepCszenVs44NYSUlcGd28yrYYWJ6aixhi+xIzzjK1R
 Fr70up4HZJdPso39d8oC
 =azkJ
 -----END PGP SIGNATURE-----

Merge tag 'arc-fixes-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
 "Some SMP changes, a ptrace request for NPTL debugging, bunch of build
  breakages/warnings"

* tag 'arc-fixes-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [SMP] Enable icache coherency
  ARC: [SMP] Fix IPI IRQ registration
  ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)
  ARC: optimize kernel bss clearing in early boot code
  ARC: Fix build breakage for !CONFIG_ARC_DW2_UNWIND
  ARC: fix build warning in devtree
  ARC: remove checks for CONFIG_ARC_MMU_V4

arch/arc/include/asm/cache.h

@@ -60,7 +60,7 @@ extern void read_decode_cache_bcr(void);
 #define ARC_REG_IC_IVIC		0x10
 #define ARC_REG_IC_CTRL		0x11
 #define ARC_REG_IC_IVIL		0x19
-#if defined(CONFIG_ARC_MMU_V3) || defined (CONFIG_ARC_MMU_V4)
+#if defined(CONFIG_ARC_MMU_V3)
 #define ARC_REG_IC_PTAG		0x1E
 #endif
 
@@ -74,7 +74,7 @@ extern void read_decode_cache_bcr(void);
 #define ARC_REG_DC_IVDL		0x4A
 #define ARC_REG_DC_FLSH		0x4B
 #define ARC_REG_DC_FLDL		0x4C
-#if defined(CONFIG_ARC_MMU_V3) || defined (CONFIG_ARC_MMU_V4)
+#if defined(CONFIG_ARC_MMU_V3)
 #define ARC_REG_DC_PTAG		0x5C
 #endif
 

arch/arc/include/uapi/asm/ptrace.h

@@ -11,6 +11,7 @@
 #ifndef _UAPI__ASM_ARC_PTRACE_H
 #define _UAPI__ASM_ARC_PTRACE_H
 
+#define PTRACE_GET_THREAD_AREA	25
 
 #ifndef __ASSEMBLY__
 /*

arch/arc/kernel/ctx_sw_asm.S

@@ -10,9 +10,9 @@
  *  -This is the more "natural" hand written assembler
  */
 
+#include <linux/linkage.h>
 #include <asm/entry.h>       /* For the SAVE_* macros */
 #include <asm/asm-offsets.h>
-#include <asm/linkage.h>
 
 #define KSP_WORD_OFF 	((TASK_THREAD + THREAD_KSP) / 4)
 

arch/arc/kernel/devtree.c

@@ -41,7 +41,7 @@ const struct machine_desc * __init setup_machine_fdt(void *dt)
 {
 	const struct machine_desc *mdesc;
 	unsigned long dt_root;
-	void *clk;
+	const void *clk;
 	int len;
 
 	if (!early_init_dt_scan(dt))

arch/arc/kernel/head.S

@@ -77,10 +77,11 @@ stext:
 	; Clear BSS before updating any globals
 	; XXX: use ZOL here
 	mov	r5, __bss_start
-	mov	r6, __bss_stop
+	sub	r6, __bss_stop, r5
+	lsr.f	lp_count, r6, 2
+	lpnz	1f
+	st.ab   0, [r5, 4]
 1:
-	st.ab   0, [r5,4]
-	brlt    r5, r6, 1b
 
 	; Uboot - kernel ABI
 	;    r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2

arch/arc/kernel/ptrace.c

@@ -146,6 +146,10 @@ long arch_ptrace(struct task_struct *child, long request,
 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
 
 	switch (request) {
+	case PTRACE_GET_THREAD_AREA:
+		ret = put_user(task_thread_info(child)->thr_ptr,
+			       (unsigned long __user *)data);
+		break;
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;

arch/arc/kernel/smp.c

@@ -337,8 +337,19 @@ irqreturn_t do_IPI(int irq, void *dev_id)
  * API called by platform code to hookup arch-common ISR to their IPI IRQ
  */
 static DEFINE_PER_CPU(int, ipi_dev);
+
+static struct irqaction arc_ipi_irq = {
+        .name    = "IPI Interrupt",
+        .flags   = IRQF_PERCPU,
+        .handler = do_IPI,
+};
+
 int smp_ipi_irq_setup(int cpu, int irq)
 {
-	int *dev_id = &per_cpu(ipi_dev, smp_processor_id());
-	return request_percpu_irq(irq, do_IPI, "IPI Interrupt", dev_id);
+	if (!cpu)
+		return setup_irq(irq, &arc_ipi_irq);
+	else
+		arch_unmask_irq(irq);
+
+	return 0;
 }

arch/arc/kernel/vmlinux.lds.S

@@ -116,7 +116,7 @@ SECTIONS
 
 	_edata = .;
 
-	BSS_SECTION(0, 0, 0)
+	BSS_SECTION(4, 4, 4)
 
 #ifdef CONFIG_ARC_DW2_UNWIND
 	. = ALIGN(PAGE_SIZE);

arch/arc/mm/cache_arc700.c

@@ -389,7 +389,7 @@ static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
 /***********************************************************
  * Machine specific helper for per line I-Cache invalidate.
  */
-static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
+static void __ic_line_inv_vaddr_local(unsigned long paddr, unsigned long vaddr,
 				unsigned long sz)
 {
 	unsigned long flags;
@@ -405,6 +405,23 @@ static inline void __ic_entire_inv(void)
 	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
 }
 
+struct ic_line_inv_vaddr_ipi {
+	unsigned long paddr, vaddr;
+	int sz;
+};
+
+static void __ic_line_inv_vaddr_helper(void *info)
+{
+        struct ic_line_inv_vaddr_ipi *ic_inv = (struct ic_line_inv_vaddr_ipi*) info;
+        __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
+}
+
+static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
+				unsigned long sz)
+{
+	struct ic_line_inv_vaddr_ipi ic_inv = { paddr, vaddr , sz};
+	on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
+}
 #else
 
 #define __ic_entire_inv()
@@ -553,12 +570,8 @@ void flush_icache_range(unsigned long kstart, unsigned long kend)
  */
 void __sync_icache_dcache(unsigned long paddr, unsigned long vaddr, int len)
 {
-	unsigned long flags;
-
-	local_irq_save(flags);
-	__ic_line_inv_vaddr(paddr, vaddr, len);
 	__dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
-	local_irq_restore(flags);
+	__ic_line_inv_vaddr(paddr, vaddr, len);
 }
 
 /* wrapper to compile time eliminate alignment checks in flush loop */