[PATCH 00/19] ARCv2 port to Linux - (A) prepratory patches

[PATCH 00/19] ARCv2 port to Linux - (A) prepratory patches

[Vineet Gupta]

Hi,

ARCv2 is the next generation ISA from Synopsys and basis for the
HS3{4,6,8} families of processors which retain the traditional ARC mantra of
low power and configurability and are now more performant and feature rich.

Linux has been ported to HS38x series, a 10 stage pipeline core which
supports MMU (with huge pages) and SMP (upto 4 cores) among other features.

 - www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
 - http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
 - http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps

This sub-series introduces changes to existing in-tree port of ARC700 core
(based on ARCompact ISA) to allow for better code sharing with new ARCv2 code.

The actual ARCv2 port will follow as a seperate series.

Please review !

Thx,
-Vineet

Vineet Gupta (19):
  ARC: mm/cache_arc700.c -> mm/cache.c
  ARC: cacheflush: move some code around, delete old comments
  ARC: cacheflush: No need to retain DC_CTRL from __before_dc_op()
  ARC: untangle cache flush loop
  ARC: entry.S: common'ize scrtach reg freeup in intr + exceptions
  ARC: entry.S: Introduce INTERRUPT_{PROLOGUE,EPILOGUE}
  ARC: entry.S: canonical'ize EXCEPTION_{PROLOGUE,EPILOGUE}
  ARC: entry.S: confine EXCEPTION_* macros to one file
  ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9
  ARC: entry.S: Trap handler to use r10 for syscall vs. brkpt decision
  ARC: entry.S: comments cleanup
  ARC: entry.S: Ensure that restore_regs is local to compilation unit
  ARC: entry.S: split into ARCompact ISA specific, common bits
  ARC: entry.S: move some code around for cache locality in return path
  ARC: entry.S: micro-optimize Trap handler
  ARC: entry.S: use single EXCEPTION_PROLOGUE
  ARC: entry.S: [arcompact] simplify SWITCH_TO_KERNEL_STK
  ARC: Make way for pt_regs != user_regs_struct
  ARC: intc: split into ARCompact ISA specific, common bits

 arch/arc/include/asm/arcregs.h          |   3 -
 arch/arc/include/asm/entry-compact.h    | 307 +++++++++++++++++++
 arch/arc/include/asm/entry.h            | 357 +---------------------
 arch/arc/include/asm/irqflags-compact.h | 181 +++++++++++
 arch/arc/include/asm/irqflags.h         | 168 +---------
 arch/arc/kernel/Makefile                |   4 +-
 arch/arc/kernel/entry-compact.S         | 393 ++++++++++++++++++++++++
 arch/arc/kernel/entry.S                 | 527 +++++---------------------------
 arch/arc/kernel/intc-compact.c          | 230 ++++++++++++++
 arch/arc/kernel/irq.c                   | 210 -------------
 arch/arc/kernel/process.c               |   3 +-
 arch/arc/kernel/ptrace.c                |  90 +++++-
 arch/arc/kernel/signal.c                |  55 +++-
 arch/arc/mm/Makefile                    |   2 +-
 arch/arc/mm/{cache_arc700.c => cache.c} | 367 ++++++++++------------
 arch/arc/mm/tlbex.S                     |  16 +-
 16 files changed, 1494 insertions(+), 1419 deletions(-)
 create mode 100644 arch/arc/include/asm/entry-compact.h
 create mode 100644 arch/arc/include/asm/irqflags-compact.h
 create mode 100644 arch/arc/kernel/entry-compact.S
 create mode 100644 arch/arc/kernel/intc-compact.c
 rename arch/arc/mm/{cache_arc700.c => cache.c} (77%)

-- 
1.9.1

[PATCH 01/19] ARC: mm/cache_arc700.c -> mm/cache.c

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/mm/Makefile                    | 2 +-
 arch/arc/mm/{cache_arc700.c => cache.c} | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename arch/arc/mm/{cache_arc700.c => cache.c} (100%)

diff --git a/arch/arc/mm/Makefile b/arch/arc/mm/Makefile
index ac95cc239c1e..7beb941556c3 100644
--- a/arch/arc/mm/Makefile
+++ b/arch/arc/mm/Makefile
@@ -7,4 +7,4 @@
 #
 
 obj-y	:= extable.o ioremap.o dma.o fault.o init.o
-obj-y	+= tlb.o tlbex.o cache_arc700.o mmap.o
+obj-y	+= tlb.o tlbex.o cache.o mmap.o
diff --git a/arch/arc/mm/cache_arc700.c b/arch/arc/mm/cache.c
similarity index 100%
rename from arch/arc/mm/cache_arc700.c
rename to arch/arc/mm/cache.c
-- 
1.9.1

[PATCH 02/19] ARC: cacheflush: move some code around, delete old comments

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/mm/cache.c | 267 ++++++++++++++++++++--------------------------------
 1 file changed, 102 insertions(+), 165 deletions(-)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 322e11b3b1e3..1d34a6978a83 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -1,64 +1,12 @@
 /*
- * ARC700 VIPT Cache Management
+ * ARC Cache Management
  *
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- *  vineetg: May 2011: for Non-aliasing VIPT D-cache following can be NOPs
- *   -flush_cache_dup_mm (fork)
- *   -likewise for flush_cache_mm (exit/execve)
- *   -likewise for flush_cache_range,flush_cache_page (munmap, exit, COW-break)
- *
- * vineetg: Apr 2011
- *  -Now that MMU can support larger pg sz (16K), the determiniation of
- *   aliasing shd not be based on assumption of 8k pg
- *
- * vineetg: Mar 2011
- *  -optimised version of flush_icache_range( ) for making I/D coherent
- *   when vaddr is available (agnostic of num of aliases)
- *
- * vineetg: Mar 2011
- *  -Added documentation about I-cache aliasing on ARC700 and the way it
- *   was handled up until MMU V2.
- *  -Spotted a three year old bug when killing the 4 aliases, which needs
- *   bottom 2 bits, so we need to do paddr | {0x00, 0x01, 0x02, 0x03}
- *                        instead of paddr | {0x00, 0x01, 0x10, 0x11}
- *   (Rajesh you owe me one now)
- *
- * vineetg: Dec 2010
- *  -Off-by-one error when computing num_of_lines to flush
- *   This broke signal handling with bionic which uses synthetic sigret stub
- *
- * vineetg: Mar 2010
- *  -GCC can't generate ZOL for core cache flush loops.
- *   Conv them into iterations based as opposed to while (start < end) types
- *
- * Vineetg: July 2009
- *  -In I-cache flush routine we used to chk for aliasing for every line INV.
- *   Instead now we setup routines per cache geometry and invoke them
- *   via function pointers.
- *
- * Vineetg: Jan 2009
- *  -Cache Line flush routines used to flush an extra line beyond end addr
- *   because check was while (end >= start) instead of (end > start)
- *     =Some call sites had to work around by doing -1, -4 etc to end param
- *     =Some callers didnt care. This was spec bad in case of INV routines
- *      which would discard valid data (cause of the horrible ext2 bug
- *      in ARC IDE driver)
- *
- * vineetg: June 11th 2008: Fixed flush_icache_range( )
- *  -Since ARC700 caches are not coherent (I$ doesnt snoop D$) both need
- *   to be flushed, which it was not doing.
- *  -load_module( ) passes vmalloc addr (Kernel Virtual Addr) to the API,
- *   however ARC cache maintenance OPs require PHY addr. Thus need to do
- *   vmalloc_to_phy.
- *  -Also added optimisation there, that for range > PAGE SIZE we flush the
- *   entire cache in one shot rather than line by line. For e.g. a module
- *   with Code sz 600k, old code flushed 600k worth of cache (line-by-line),
- *   while cache is only 16 or 32k.
  */
 
 #include <linux/module.h>
@@ -142,54 +90,8 @@ dc_chk:
 }
 
 /*
- * 1. Validate the Cache Geomtery (compile time config matches hardware)
- * 2. If I-cache suffers from aliasing, setup work arounds (difft flush rtn)
- *    (aliasing D-cache configurations are not supported YET)
- * 3. Enable the Caches, setup default flush mode for D-Cache
- * 3. Calculate the SHMLBA used by user space
+ * Line Operation on {I,D}-Cache
  */
-void arc_cache_init(void)
-{
-	unsigned int __maybe_unused cpu = smp_processor_id();
-	char str[256];
-
-	printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
-
-	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
-		struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
-
-		if (!ic->ver)
-			panic("cache support enabled but non-existent cache\n");
-
-		if (ic->line_len != L1_CACHE_BYTES)
-			panic("ICache line [%d] != kernel Config [%d]",
-			      ic->line_len, L1_CACHE_BYTES);
-
-		if (ic->ver != CONFIG_ARC_MMU_VER)
-			panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
-			      ic->ver, CONFIG_ARC_MMU_VER);
-	}
-
-	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
-		struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
-		int handled;
-
-		if (!dc->ver)
-			panic("cache support enabled but non-existent cache\n");
-
-		if (dc->line_len != L1_CACHE_BYTES)
-			panic("DCache line [%d] != kernel Config [%d]",
-			      dc->line_len, L1_CACHE_BYTES);
-
-		/* check for D-Cache aliasing */
-		handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
-
-		if (dc->alias && !handled)
-			panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
-		else if (!dc->alias && handled)
-			panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
-	}
-}
 
 #define OP_INV		0x1
 #define OP_FLUSH	0x2
@@ -197,16 +99,55 @@ void arc_cache_init(void)
 #define OP_INV_IC	0x4
 
 /*
- * Common Helper for Line Operations on {I,D}-Cache
+ *		I-Cache Aliasing in ARC700 VIPT caches (MMU v1-v3)
+ *
+ * ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
+ * The orig Cache Management Module "CDU" only required paddr to invalidate a
+ * certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
+ * Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
+ * the exact same line.
+ *
+ * However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
+ * paddr alone could not be used to correctly index the cache.
+ *
+ * ------------------
+ * MMU v1/v2 (Fixed Page Size 8k)
+ * ------------------
+ * The solution was to provide CDU with these additonal vaddr bits. These
+ * would be bits [x:13], x would depend on cache-geometry, 13 comes from
+ * standard page size of 8k.
+ * H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
+ * of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
+ * orig 5 bits of paddr were anyways ignored by CDU line ops, as they
+ * represent the offset within cache-line. The adv of using this "clumsy"
+ * interface for additional info was no new reg was needed in CDU programming
+ * model.
+ *
+ * 17:13 represented the max num of bits passable, actual bits needed were
+ * fewer, based on the num-of-aliases possible.
+ * -for 2 alias possibility, only bit 13 needed (32K cache)
+ * -for 4 alias possibility, bits 14:13 needed (64K cache)
+ *
+ * ------------------
+ * MMU v3
+ * ------------------
+ * This ver of MMU supports variable page sizes (1k-16k): although Linux will
+ * only support 8k (default), 16k and 4k.
+ * However from hardware perspective, smaller page sizes aggrevate aliasing
+ * meaning more vaddr bits needed to disambiguate the cache-line-op ;
+ * the existing scheme of piggybacking won't work for certain configurations.
+ * Two new registers IC_PTAG and DC_PTAG inttoduced.
+ * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
  */
+
 static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
-				     unsigned long sz, const int cacheop)
+				     unsigned long sz, const int op)
 {
 	unsigned int aux_cmd, aux_tag;
 	int num_lines;
 	const int full_page_op = __builtin_constant_p(sz) && sz == PAGE_SIZE;
 
-	if (cacheop == OP_INV_IC) {
+	if (op == OP_INV_IC) {
 		aux_cmd = ARC_REG_IC_IVIL;
 #if (CONFIG_ARC_MMU_VER > 2)
 		aux_tag = ARC_REG_IC_PTAG;
@@ -214,7 +155,7 @@ static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
 	}
 	else {
 		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
-		aux_cmd = cacheop & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
+		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
 #if (CONFIG_ARC_MMU_VER > 2)
 		aux_tag = ARC_REG_DC_PTAG;
 #endif
@@ -296,107 +237,60 @@ static inline void __after_dc_op(const int op, unsigned int reg)
 
 /*
  * Operation on Entire D-Cache
- * @cacheop = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
+ * @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
  * Note that constant propagation ensures all the checks are gone
  * in generated code
  */
-static inline void __dc_entire_op(const int cacheop)
+static inline void __dc_entire_op(const int op)
 {
 	unsigned int ctrl_reg;
 	int aux;
 
-	ctrl_reg = __before_dc_op(cacheop);
+	ctrl_reg = __before_dc_op(op);
 
-	if (cacheop & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
+	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
 		aux = ARC_REG_DC_IVDC;
 	else
 		aux = ARC_REG_DC_FLSH;
 
 	write_aux_reg(aux, 0x1);
 
-	__after_dc_op(cacheop, ctrl_reg);
+	__after_dc_op(op, ctrl_reg);
 }
 
 /* For kernel mappings cache operation: index is same as paddr */
 #define __dc_line_op_k(p, sz, op)	__dc_line_op(p, p, sz, op)
 
 /*
- * D-Cache : Per Line INV (discard or wback+discard) or FLUSH (wback)
+ * Operation on D-Cache: Per Line INV (discard or wback+discard) or FLUSH (wback)
  */
 static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
-				unsigned long sz, const int cacheop)
+				unsigned long sz, const int op)
 {
 	unsigned long flags;
 	unsigned int ctrl_reg;
 
 	local_irq_save(flags);
 
-	ctrl_reg = __before_dc_op(cacheop);
+	ctrl_reg = __before_dc_op(op);
 
-	__cache_line_loop(paddr, vaddr, sz, cacheop);
+	__cache_line_loop(paddr, vaddr, sz, op);
 
-	__after_dc_op(cacheop, ctrl_reg);
+	__after_dc_op(op, ctrl_reg);
 
 	local_irq_restore(flags);
 }
 
 #else
 
-#define __dc_entire_op(cacheop)
-#define __dc_line_op(paddr, vaddr, sz, cacheop)
-#define __dc_line_op_k(paddr, sz, cacheop)
+#define __dc_entire_op(op)
+#define __dc_line_op(paddr, vaddr, sz, op)
+#define __dc_line_op_k(paddr, sz, op)
 
 #endif /* CONFIG_ARC_HAS_DCACHE */
 
-
 #ifdef CONFIG_ARC_HAS_ICACHE
 
-/*
- *		I-Cache Aliasing in ARC700 VIPT caches
- *
- * ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
- * The orig Cache Management Module "CDU" only required paddr to invalidate a
- * certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
- * Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
- * the exact same line.
- *
- * However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
- * paddr alone could not be used to correctly index the cache.
- *
- * ------------------
- * MMU v1/v2 (Fixed Page Size 8k)
- * ------------------
- * The solution was to provide CDU with these additonal vaddr bits. These
- * would be bits [x:13], x would depend on cache-geometry, 13 comes from
- * standard page size of 8k.
- * H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
- * of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
- * orig 5 bits of paddr were anyways ignored by CDU line ops, as they
- * represent the offset within cache-line. The adv of using this "clumsy"
- * interface for additional info was no new reg was needed in CDU programming
- * model.
- *
- * 17:13 represented the max num of bits passable, actual bits needed were
- * fewer, based on the num-of-aliases possible.
- * -for 2 alias possibility, only bit 13 needed (32K cache)
- * -for 4 alias possibility, bits 14:13 needed (64K cache)
- *
- * ------------------
- * MMU v3
- * ------------------
- * This ver of MMU supports variable page sizes (1k-16k): although Linux will
- * only support 8k (default), 16k and 4k.
- * However from hardware perspective, smaller page sizes aggrevate aliasing
- * meaning more vaddr bits needed to disambiguate the cache-line-op ;
- * the existing scheme of piggybacking won't work for certain configurations.
- * Two new registers IC_PTAG and DC_PTAG inttoduced.
- * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
- */
-
-/***********************************************************
- * Machine specific helper for per line I-Cache invalidate.
- */
-
 static inline void __ic_entire_inv(void)
 {
 	write_aux_reg(ARC_REG_IC_IVIC, 1);
@@ -721,3 +615,46 @@ SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
 	flush_cache_all();
 	return 0;
 }
+
+void arc_cache_init(void)
+{
+	unsigned int __maybe_unused cpu = smp_processor_id();
+	char str[256];
+
+	printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
+
+	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
+		struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
+
+		if (!ic->ver)
+			panic("cache support enabled but non-existent cache\n");
+
+		if (ic->line_len != L1_CACHE_BYTES)
+			panic("ICache line [%d] != kernel Config [%d]",
+			      ic->line_len, L1_CACHE_BYTES);
+
+		if (ic->ver != CONFIG_ARC_MMU_VER)
+			panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
+			      ic->ver, CONFIG_ARC_MMU_VER);
+	}
+
+	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
+		struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
+		int handled;
+
+		if (!dc->ver)
+			panic("cache support enabled but non-existent cache\n");
+
+		if (dc->line_len != L1_CACHE_BYTES)
+			panic("DCache line [%d] != kernel Config [%d]",
+			      dc->line_len, L1_CACHE_BYTES);
+
+		/* check for D-Cache aliasing */
+		handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
+
+		if (dc->alias && !handled)
+			panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+		else if (!dc->alias && handled)
+			panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
+	}
+}
-- 
1.9.1

[PATCH 03/19] ARC: cacheflush: No need to retain DC_CTRL from __before_dc_op()

[Vineet Gupta]

That is because __after_dc_op() already reads it for status check, so it
is better anyways to use that "newer" value.

Also reduces the clutter in callers for passing from/to these routines.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/mm/cache.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 1d34a6978a83..7ff54d024b11 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -207,32 +207,32 @@ static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
  * Machine specific helpers for Entire D-Cache or Per Line ops
  */
 
-static inline unsigned int __before_dc_op(const int op)
+static inline void __before_dc_op(const int op)
 {
-	unsigned int reg = reg;
-
 	if (op == OP_FLUSH_N_INV) {
 		/* Dcache provides 2 cmd: FLUSH or INV
 		 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
 		 * flush-n-inv is achieved by INV cmd but with IM=1
 		 * So toggle INV sub-mode depending on op request and default
 		 */
-		reg = read_aux_reg(ARC_REG_DC_CTRL);
-		write_aux_reg(ARC_REG_DC_CTRL, reg | DC_CTRL_INV_MODE_FLUSH)
+		write_aux_reg(ARC_REG_DC_CTRL,
+			      read_aux_reg(ARC_REG_DC_CTRL) | DC_CTRL_INV_MODE_FLUSH)
 			;
 	}
-
-	return reg;
 }
 
-static inline void __after_dc_op(const int op, unsigned int reg)
+static inline void __after_dc_op(const int op)
 {
-	if (op & OP_FLUSH)	/* flush / flush-n-inv both wait */
-		while (read_aux_reg(ARC_REG_DC_CTRL) & DC_CTRL_FLUSH_STATUS);
+	if (op & OP_FLUSH) {
+		unsigned int reg;
 
-	/* Switch back to default Invalidate mode */
-	if (op == OP_FLUSH_N_INV)
-		write_aux_reg(ARC_REG_DC_CTRL, reg & ~DC_CTRL_INV_MODE_FLUSH);
+		/* flush / flush-n-inv both wait */
+		while ((reg = read_aux_reg(ARC_REG_DC_CTRL)) & DC_CTRL_FLUSH_STATUS);
+
+		/* Switch back to default Invalidate mode */
+		if (op == OP_FLUSH_N_INV)
+			write_aux_reg(ARC_REG_DC_CTRL, reg & ~DC_CTRL_INV_MODE_FLUSH);
+	}
 }
 
 /*
@@ -243,10 +243,9 @@ static inline void __after_dc_op(const int op, unsigned int reg)
  */
 static inline void __dc_entire_op(const int op)
 {
-	unsigned int ctrl_reg;
 	int aux;
 
-	ctrl_reg = __before_dc_op(op);
+	__before_dc_op(op);
 
 	if (op & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
 		aux = ARC_REG_DC_IVDC;
@@ -255,7 +254,7 @@ static inline void __dc_entire_op(const int op)
 
 	write_aux_reg(aux, 0x1);
 
-	__after_dc_op(op, ctrl_reg);
+	__after_dc_op(op);
 }
 
 /* For kernel mappings cache operation: index is same as paddr */
@@ -268,15 +267,14 @@ static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
 				unsigned long sz, const int op)
 {
 	unsigned long flags;
-	unsigned int ctrl_reg;
 
 	local_irq_save(flags);
 
-	ctrl_reg = __before_dc_op(op);
+	__before_dc_op(op);
 
 	__cache_line_loop(paddr, vaddr, sz, op);
 
-	__after_dc_op(op, ctrl_reg);
+	__after_dc_op(op);
 
 	local_irq_restore(flags);
 }
-- 
1.9.1

[PATCH 04/19] ARC: untangle cache flush loop

[Vineet Gupta]

- Remove the ifdef'ery and write distinct versions for each mmu ver even
  if there is some code duplication

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/mm/cache.c | 80 ++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 55 insertions(+), 25 deletions(-)

diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 7ff54d024b11..2db777a5d926 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -140,25 +140,19 @@ dc_chk:
  * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
  */
 
-static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
-				     unsigned long sz, const int op)
+static inline
+void __cache_line_loop_v2(unsigned long paddr, unsigned long vaddr,
+			  unsigned long sz, const int op)
 {
-	unsigned int aux_cmd, aux_tag;
+	unsigned int aux_cmd;
 	int num_lines;
-	const int full_page_op = __builtin_constant_p(sz) && sz == PAGE_SIZE;
+	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
 
 	if (op == OP_INV_IC) {
 		aux_cmd = ARC_REG_IC_IVIL;
-#if (CONFIG_ARC_MMU_VER > 2)
-		aux_tag = ARC_REG_IC_PTAG;
-#endif
-	}
-	else {
+	} else {
 		/* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
 		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
-#if (CONFIG_ARC_MMU_VER > 2)
-		aux_tag = ARC_REG_DC_PTAG;
-#endif
 	}
 
 	/* Ensure we properly floor/ceil the non-line aligned/sized requests
@@ -167,7 +161,7 @@ static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
 	 *  -@paddr will be cache-line aligned already (being page aligned)
 	 *  -@sz will be integral multiple of line size (being page sized).
 	 */
-	if (!full_page_op) {
+	if (!full_page) {
 		sz += paddr & ~CACHE_LINE_MASK;
 		paddr &= CACHE_LINE_MASK;
 		vaddr &= CACHE_LINE_MASK;
@@ -175,32 +169,68 @@ static inline void __cache_line_loop(unsigned long paddr, unsigned long vaddr,
 
 	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
 
-#if (CONFIG_ARC_MMU_VER <= 2)
 	/* MMUv2 and before: paddr contains stuffed vaddrs bits */
 	paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
-#else
-	/* if V-P const for loop, PTAG can be written once outside loop */
-	if (full_page_op)
+
+	while (num_lines-- > 0) {
+		write_aux_reg(aux_cmd, paddr);
+		paddr += L1_CACHE_BYTES;
+	}
+}
+
+static inline
+void __cache_line_loop_v3(unsigned long paddr, unsigned long vaddr,
+			  unsigned long sz, const int op)
+{
+	unsigned int aux_cmd, aux_tag;
+	int num_lines;
+	const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE;
+
+	if (op == OP_INV_IC) {
+		aux_cmd = ARC_REG_IC_IVIL;
+		aux_tag = ARC_REG_IC_PTAG;
+	} else {
+		aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
+		aux_tag = ARC_REG_DC_PTAG;
+	}
+
+	/* Ensure we properly floor/ceil the non-line aligned/sized requests
+	 * and have @paddr - aligned to cache line and integral @num_lines.
+	 * This however can be avoided for page sized since:
+	 *  -@paddr will be cache-line aligned already (being page aligned)
+	 *  -@sz will be integral multiple of line size (being page sized).
+	 */
+	if (!full_page) {
+		sz += paddr & ~CACHE_LINE_MASK;
+		paddr &= CACHE_LINE_MASK;
+		vaddr &= CACHE_LINE_MASK;
+	}
+	num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
+
+	/*
+	 * MMUv3, cache ops require paddr seperately
+	 * if V-P const for loop, PTAG can be written once outside loop
+	 */
+	if (full_page)
 		write_aux_reg(aux_tag, paddr);
-#endif
 
 	while (num_lines-- > 0) {
-#if (CONFIG_ARC_MMU_VER > 2)
-		/* MMUv3, cache ops require paddr seperately */
-		if (!full_page_op) {
+		if (!full_page) {
 			write_aux_reg(aux_tag, paddr);
 			paddr += L1_CACHE_BYTES;
 		}
 
 		write_aux_reg(aux_cmd, vaddr);
 		vaddr += L1_CACHE_BYTES;
-#else
-		write_aux_reg(aux_cmd, paddr);
-		paddr += L1_CACHE_BYTES;
-#endif
 	}
 }
 
+#if (CONFIG_ARC_MMU_VER < 3)
+#define __cache_line_loop	__cache_line_loop_v2
+#elif (CONFIG_ARC_MMU_VER == 3)
+#define __cache_line_loop	__cache_line_loop_v3
+#endif
+
 #ifdef CONFIG_ARC_HAS_DCACHE
 
 /***************************************************************
-- 
1.9.1

[PATCH 05/19] ARC: entry.S: common'ize scrtach reg freeup in intr + exceptions

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry.h | 35 ++++++++++++++++-------------------
 arch/arc/kernel/entry.S      | 10 ++--------
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 884081099f80..9e844ab5eede 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -360,26 +360,26 @@
 .endm
 
 /*--------------------------------------------------------------
- * For early Exception Prologue, a core reg is temporarily needed to
+ * For early Exception/ISR Prologue, a core reg is temporarily needed to
  * code the rest of prolog (stack switching). This is done by stashing
  * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP).
  *
  * Before saving the full regfile - this reg is restored back, only
  * to be saved again on kernel mode stack, as part of pt_regs.
  *-------------------------------------------------------------*/
-.macro EXCPN_PROLOG_FREEUP_REG	reg
+.macro PROLOG_FREEUP_REG	reg, mem
 #ifdef CONFIG_SMP
 	sr  \reg, [ARC_REG_SCRATCH_DATA0]
 #else
-	st  \reg, [@ex_saved_reg1]
+	st  \reg, [\mem]
 #endif
 .endm
 
-.macro EXCPN_PROLOG_RESTORE_REG	reg
+.macro PROLOG_RESTORE_REG	reg, mem
 #ifdef CONFIG_SMP
 	lr  \reg, [ARC_REG_SCRATCH_DATA0]
 #else
-	ld  \reg, [@ex_saved_reg1]
+	ld  \reg, [\mem]
 #endif
 .endm
 
@@ -393,7 +393,7 @@
 .macro EXCEPTION_PROLOGUE
 
 	/* Need at least 1 reg to code the early exception prologue */
-	EXCPN_PROLOG_FREEUP_REG r9
+	PROLOG_FREEUP_REG r9, @ex_saved_reg1
 
 	/* U/K mode at time of exception (stack not switched if already K) */
 	lr  r9, [erstatus]
@@ -421,7 +421,7 @@
 	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
 
 	/* Restore r9 used to code the early prologue */
-	EXCPN_PROLOG_RESTORE_REG  r9
+	PROLOG_RESTORE_REG  r9, @ex_saved_reg1
 
 	SAVE_R0_TO_R12
 	PUSH	gp
@@ -471,12 +471,8 @@
  *-------------------------------------------------------------*/
 .macro SAVE_ALL_INT1
 
-	/* restore original r9 to be saved as part of reg-file */
-#ifdef CONFIG_SMP
-	lr  r9, [ARC_REG_SCRATCH_DATA0]
-#else
-	ld  r9, [@int1_saved_reg]
-#endif
+	/* restore original r9 */
+	PROLOG_RESTORE_REG  r9, @int1_saved_reg
 
 	/* now we are ready to save the remaining context :) */
 	st      event_IRQ1, [sp, 8]    /* Dummy ECR */
@@ -496,12 +492,13 @@
 
 .macro SAVE_ALL_INT2
 
-	/* TODO-vineetg: SMP we can't use global nor can we use
-	*   SCRATCH0 as we do for int1 because while int1 is using
-	*   it, int2 can come
-	*/
-	/* retsore original r9 , saved in sys_saved_r9 */
-	ld  r9, [@int2_saved_reg]
+	/*
+	 * In SMP we can't use mem nor can we use SCRARCH_DATA0
+	 * as we do for int1 because int2 can clobber it
+	 * Hence 2 levels of intr are NOT allowed in SMP (by Kconfig)
+	 */
+	/* restore original r9 */
+	PROLOG_RESTORE_REG r9, @int2_saved_reg
 
 	/* now we are ready to save the remaining context :) */
 	st      event_IRQ2, [sp, 8]    /* Dummy ECR */
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index d868289c5a26..13b14b8dcd8d 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -186,9 +186,8 @@ reserved:		; processor restart
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level2)
 
-	; TODO-vineetg for SMP this wont work
 	; free up r9 as scratchpad
-	st  r9, [@int2_saved_reg]
+	PROLOG_FREEUP_REG r9, @int2_saved_reg
 
 	;Which mode (user/kernel) was the system in when intr occured
 	lr  r9, [status32_l2]
@@ -234,12 +233,7 @@ END(handle_interrupt_level2)
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level1)
 
-	/* free up r9 as scratchpad */
-#ifdef CONFIG_SMP
-	sr  r9, [ARC_REG_SCRATCH_DATA0]
-#else
-	st   r9, [@int1_saved_reg]
-#endif
+	PROLOG_FREEUP_REG r9, @int1_saved_reg
 
 	;Which mode (user/kernel) was the system in when intr occured
 	lr  r9, [status32_l1]
-- 
1.9.1

[PATCH 06/19] ARC: entry.S: Introduce INTERRUPT_{PROLOGUE,EPILOGUE}

[Vineet Gupta]

-common'ize macros for level 1 and level 2 interrupts

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/arcregs.h |  3 --
 arch/arc/include/asm/entry.h   | 77 +++++++++++-------------------------------
 arch/arc/kernel/entry.S        | 22 +++---------
 3 files changed, 23 insertions(+), 79 deletions(-)

diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index e42a5f8b05aa..336a9f694c2e 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -76,9 +76,6 @@
 #define ECR_C_BIT_DTLB_LD_MISS		8
 #define ECR_C_BIT_DTLB_ST_MISS		9
 
-/* Dummy ECR values for Interrupts */
-#define event_IRQ1		0x0031abcd
-#define event_IRQ2		0x0032abcd
 
 /* Auxiliary registers */
 #define AUX_IDENTITY		4
diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 9e844ab5eede..35c4111d8c80 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -465,55 +465,37 @@
 	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
+/* Dummy ECR values for Interrupts */
+#define event_IRQ1		0x0031abcd
+#define event_IRQ2		0x0032abcd
 
-/*--------------------------------------------------------------
- * Save all registers used by interrupt handlers.
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_INT1
+.macro INTERRUPT_PROLOGUE  LVL
 
-	/* restore original r9 */
-	PROLOG_RESTORE_REG  r9, @int1_saved_reg
+	/* free up r9 as scratchpad */
+	PROLOG_FREEUP_REG r9, @int\LVL\()_saved_reg
 
-	/* now we are ready to save the remaining context :) */
-	st      event_IRQ1, [sp, 8]    /* Dummy ECR */
-	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
+	/* Which mode (user/kernel) was the system in when intr occured */
+	lr  r9, [status32_l\LVL\()]
 
-	SAVE_R0_TO_R12
-	PUSH	gp
-	PUSH	fp
-	PUSH	blink
-	PUSH	ilink1
-	PUSHAX	status32_l1
-	PUSH	lp_count
-	PUSHAX	lp_end
-	PUSHAX	lp_start
-	PUSHAX	bta_l1
-.endm
-
-.macro SAVE_ALL_INT2
+	SWITCH_TO_KERNEL_STK
 
-	/*
-	 * In SMP we can't use mem nor can we use SCRARCH_DATA0
-	 * as we do for int1 because int2 can clobber it
-	 * Hence 2 levels of intr are NOT allowed in SMP (by Kconfig)
-	 */
 	/* restore original r9 */
-	PROLOG_RESTORE_REG r9, @int2_saved_reg
+	PROLOG_RESTORE_REG  r9, @int\LVL\()_saved_reg
 
-	/* now we are ready to save the remaining context :) */
-	st      event_IRQ2, [sp, 8]    /* Dummy ECR */
+	/* now we are ready to save the remaining context */
+	st      0x003\LVL\()abcd, [sp, 8]    /* Dummy ECR */
 	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
 
 	SAVE_R0_TO_R12
 	PUSH	gp
 	PUSH	fp
 	PUSH	blink
-	PUSH	ilink2
-	PUSHAX	status32_l2
+	PUSH	ilink\LVL\()
+	PUSHAX	status32_l\LVL\()
 	PUSH	lp_count
 	PUSHAX	lp_end
 	PUSHAX	lp_start
-	PUSHAX	bta_l2
+	PUSHAX	bta_l\LVL\()
 .endm
 
 /*--------------------------------------------------------------
@@ -525,17 +507,16 @@
  * for memory load operations. If used in that way interrupts are deffered
  * by hardware and that is not good.
  *-------------------------------------------------------------*/
-
-.macro RESTORE_ALL_INT1
-	POPAX	bta_l1
+.macro INTERRUPT_EPILOGUE  LVL
+	POPAX	bta_l\LVL\()
 	POPAX	lp_start
 	POPAX	lp_end
 
 	POP	r9
 	mov	lp_count, r9	;LD to lp_count is not allowed
 
-	POPAX	status32_l1
-	POP	ilink1
+	POPAX	status32_l\LVL\()
+	POP	ilink\LVL\()
 	POP	blink
 	POP	fp
 	POP	gp
@@ -545,26 +526,6 @@
 	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
-.macro RESTORE_ALL_INT2
-	POPAX	bta_l2
-	POPAX	lp_start
-	POPAX	lp_end
-
-	POP	r9
-	mov	lp_count, r9	;LD to lp_count is not allowed
-
-	POPAX	status32_l2
-	POP	ilink2
-	POP	blink
-	POP	fp
-	POP	gp
-	RESTORE_R12_TO_R0
-
-	ld  sp, [sp] /* restore original sp */
-	/* orig_r0, ECR, user_r25 skipped automatically */
-.endm
-
-
 /* Get CPU-ID of this core */
 .macro  GET_CPU_ID  reg
 	lr  \reg, [identity]
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 13b14b8dcd8d..03a349520b55 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -186,14 +186,7 @@ reserved:		; processor restart
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level2)
 
-	; free up r9 as scratchpad
-	PROLOG_FREEUP_REG r9, @int2_saved_reg
-
-	;Which mode (user/kernel) was the system in when intr occured
-	lr  r9, [status32_l2]
-
-	SWITCH_TO_KERNEL_STK
-	SAVE_ALL_INT2
+	INTERRUPT_PROLOGUE 2
 
 	;------------------------------------------------------
 	; if L2 IRQ interrupted a L1 ISR, disable preemption
@@ -233,13 +226,7 @@ END(handle_interrupt_level2)
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level1)
 
-	PROLOG_FREEUP_REG r9, @int1_saved_reg
-
-	;Which mode (user/kernel) was the system in when intr occured
-	lr  r9, [status32_l1]
-
-	SWITCH_TO_KERNEL_STK
-	SAVE_ALL_INT1
+	INTERRUPT_PROLOGUE 1
 
 	lr  r0, [icause1]
 	and r0, r0, 0x1f
@@ -698,7 +685,7 @@ not_exception:
 
 149:
 	;return from level 2
-	RESTORE_ALL_INT2
+	INTERRUPT_EPILOGUE 2
 debug_marker_l2:
 	rtie
 
@@ -709,8 +696,7 @@ not_level2_interrupt:
 	bbit0  r10, STATUS_A1_BIT, not_level1_interrupt
 
 	;return from level 1
-
-	RESTORE_ALL_INT1
+	INTERRUPT_EPILOGUE 1
 debug_marker_l1:
 	rtie
 
-- 
1.9.1

[PATCH 07/19] ARC: entry.S: canonical'ize EXCEPTION_{PROLOGUE,EPILOGUE}

[Vineet Gupta]

-EXCEPTION_EPILOGUE introduced
-EXCEPTION_PROLOGUE now also includes reg file saving

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry.h | 17 +----------------
 arch/arc/kernel/entry.S      |  4 ++--
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 35c4111d8c80..e880a5f1b2e4 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -401,21 +401,6 @@
 	/* ARC700 doesn't provide auto-stack switching */
 	SWITCH_TO_KERNEL_STK
 
-	/* save the regfile */
-	SAVE_ALL_SYS
-.endm
-
-/*--------------------------------------------------------------
- * Save all registers used by Exceptions (TLB Miss, Prot-V, Mem err etc)
- * Requires SP to be already switched to kernel mode Stack
- * sp points to the next free element on the stack at exit of this macro.
- * Registers are pushed / popped in the order defined in struct ptregs
- * in asm/ptrace.h
- * Note that syscalls are implemented via TRAP which is also a exception
- * from CPU's point of view
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_SYS
-
 	lr	r9, [ecr]
 	st      r9, [sp, 8]    /* ECR */
 	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
@@ -446,7 +431,7 @@
  * for memory load operations. If used in that way interrupts are deffered
  * by hardware and that is not good.
  *-------------------------------------------------------------*/
-.macro RESTORE_ALL_SYS
+.macro EXCEPTION_EPILOGUE
 	POPAX	erbta
 	POPAX	lp_start
 	POPAX	lp_end
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 03a349520b55..d8ec722a936b 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -638,7 +638,7 @@ restore_regs :
 
 	; if Returning from Exception
 	bbit0  r10, STATUS_AE_BIT, not_exception
-	RESTORE_ALL_SYS
+	EXCEPTION_EPILOGUE
 	rtie
 
 	; Not Exception so maybe Interrupts (Level 1 or 2)
@@ -704,7 +704,7 @@ not_level1_interrupt:
 
 	;this case is for syscalls or Exceptions (with fake rtie)
 
-	RESTORE_ALL_SYS
+	EXCEPTION_EPILOGUE
 debug_marker_syscall:
 	rtie
 
-- 
1.9.1

[PATCH 08/19] ARC: entry.S: confine EXCEPTION_* macros to one file

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry.S | 16 ++++++++++++++++
 arch/arc/mm/tlbex.S     | 16 +---------------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index d8ec722a936b..6cced37e7a76 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -368,6 +368,22 @@ ENTRY(EV_TLBProtV)
 
 END(EV_TLBProtV)
 
+; Wrapper for Linux page fault handler called from EV_TLBMiss*
+; Very similar to ProtV handler case (6a) above, but avoids the extra checks
+; for Misaligned access
+;
+ENTRY(call_do_page_fault)
+
+	EXCEPTION_PROLOGUE
+	lr  r0, [efa]	; Faulting Data address
+	mov   r1, sp
+	FAKE_RET_FROM_EXCPN r9
+
+	mov blink, ret_from_exception
+	b  do_page_fault
+
+END(call_do_page_fault)
+
 ; ---------------------------------------------
 ; Privilege Violation Exception Handler
 ; ---------------------------------------------
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index d572f1c2c724..d224bf0feefc 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -366,19 +366,5 @@ do_slow_path_pf:
 
 	; Slow path TLB Miss handled as a regular ARC Exception
 	; (stack switching / save the complete reg-file).
-	EXCEPTION_PROLOGUE
-
-	; ------- setup args for Linux Page fault Hanlder ---------
-	mov_s r1, sp
-	lr    r0, [efa]
-
-	; We don't want exceptions to be disabled while the fault is handled.
-	; Now that we have saved the context we return from exception hence
-	; exceptions get re-enable
-
-	FAKE_RET_FROM_EXCPN  r9
-
-	bl  do_page_fault
-	b   ret_from_exception
-
+	b  call_do_page_fault
 END(EV_TLBMissD)
-- 
1.9.1

[PATCH 09/19] ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry.h | 16 ++++++++--------
 arch/arc/kernel/entry.S      | 24 +++++++++++-------------
 2 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index e880a5f1b2e4..c976b54c9b07 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -331,14 +331,14 @@
  * Look at EV_ProtV to see how this is actually used
  *-------------------------------------------------------------*/
 
-.macro FAKE_RET_FROM_EXCPN  reg
-
-	ld  \reg, [sp, PT_status32]
-	bic  \reg, \reg, (STATUS_U_MASK|STATUS_DE_MASK)
-	bset \reg, \reg, STATUS_L_BIT
-	sr  \reg, [erstatus]
-	mov \reg, 55f
-	sr  \reg, [eret]
+.macro FAKE_RET_FROM_EXCPN
+
+	ld  r9, [sp, PT_status32]
+	bic  r9, r9, (STATUS_U_MASK|STATUS_DE_MASK)
+	bset r9, r9, STATUS_L_BIT
+	sr  r9, [erstatus]
+	mov r9, 55f
+	sr  r9, [eret]
 
 	rtie
 55:
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 6cced37e7a76..0a75f81e2853 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -261,7 +261,7 @@ ENTRY(instr_service)
 	lr  r0, [efa]
 	mov r1, sp
 
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	bl  do_insterror_or_kprobe
 	b   ret_from_exception
@@ -278,7 +278,7 @@ ENTRY(mem_service)
 	lr  r0, [efa]
 	mov r1, sp
 
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	bl  do_memory_error
 	b   ret_from_exception
@@ -330,12 +330,11 @@ ENTRY(EV_TLBProtV)
 	lr  r2, [ecr]
 	lr  r0, [efa]	; Faulting Data address
 
-	; --------(4) Return from CPU Exception Mode ---------
-	;  Fake a rtie, but rtie to next label
-	;  That way, subsequently, do_page_fault ( ) executes in pure kernel
-	;  mode with further Exceptions enabled
+	; Exception auto-disables further Intr/exceptions.
+	; Re-enable them by pretending to return from exception
+	; (so rest of handler executes in pure K mode)
 
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	mov   r1, sp
 
@@ -377,7 +376,7 @@ ENTRY(call_do_page_fault)
 	EXCEPTION_PROLOGUE
 	lr  r0, [efa]	; Faulting Data address
 	mov   r1, sp
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	mov blink, ret_from_exception
 	b  do_page_fault
@@ -394,7 +393,7 @@ ENTRY(EV_PrivilegeV)
 	lr  r0, [efa]
 	mov r1, sp
 
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	bl  do_privilege_fault
 	b   ret_from_exception
@@ -410,7 +409,7 @@ ENTRY(EV_Extension)
 	lr  r0, [efa]
 	mov r1, sp
 
-	FAKE_RET_FROM_EXCPN r9
+	FAKE_RET_FROM_EXCPN
 
 	bl  do_extension_fault
 	b   ret_from_exception
@@ -472,7 +471,7 @@ trap_with_param:
 
 	; Now that we have read EFA, it is safe to do "fake" rtie
 	;   and get out of CPU exception mode
-	FAKE_RET_FROM_EXCPN r11
+	FAKE_RET_FROM_EXCPN
 
 	; Save callee regs in case gdb wants to have a look
 	; SP will grow up by size of CALLEE Reg-File
@@ -512,8 +511,7 @@ ENTRY(EV_Trap)
 
 	; ======= (5a) Trap is due to System Call ========
 
-	; Before doing anything, return from CPU Exception Mode
-	FAKE_RET_FROM_EXCPN r11
+	FAKE_RET_FROM_EXCPN
 
 	; If syscall tracing ongoing, invoke pre-pos-hooks
 	GET_CURR_THR_INFO_FLAGS   r10
-- 
1.9.1

[PATCH 10/19] ARC: entry.S: Trap handler to use r10 for syscall vs. brkpt decision

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 0a75f81e2853..b120f3e1e13e 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -505,8 +505,8 @@ ENTRY(EV_Trap)
 	EXCEPTION_PROLOGUE
 
 	;------- (4) What caused the Trap --------------
-	lr     r12, [ecr]
-	bmsk.f 0, r12, 7
+	lr     r10, [ecr]
+	bmsk.f 0, r10, 7
 	bnz    trap_with_param
 
 	; ======= (5a) Trap is due to System Call ========
-- 
1.9.1

[PATCH 11/19] ARC: entry.S: comments cleanup

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry.S | 46 ++++++++++++++++++++--------------------------
 1 file changed, 20 insertions(+), 26 deletions(-)

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index b120f3e1e13e..a07cec4688ce 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -322,13 +322,8 @@ ENTRY(EV_TLBProtV)
 
 	EXCEPTION_PROLOGUE
 
-	;---------(3) Save some more regs-----------------
-	;  vineetg: Mar 6th: Random Seg Fault issue #1
-	;  ecr and efa were not saved in case an Intr sneaks in
-	;  after fake rtie
-
 	lr  r2, [ecr]
-	lr  r0, [efa]	; Faulting Data address
+	lr  r0, [efa]	; Faulting Data address (not part of pt_regs saved above)
 
 	; Exception auto-disables further Intr/exceptions.
 	; Re-enable them by pretending to return from exception
@@ -336,7 +331,7 @@ ENTRY(EV_TLBProtV)
 
 	FAKE_RET_FROM_EXCPN
 
-	mov   r1, sp
+	mov   r1, sp	; Handle to pt_regs
 
 	;------ (5) Type of Protection Violation? ----------
 	;
@@ -415,8 +410,11 @@ ENTRY(EV_Extension)
 	b   ret_from_exception
 END(EV_Extension)
 
-;######################### System Call Tracing #########################
+;################ Trap Handling (Syscall, Breakpoint) ##################
 
+; ---------------------------------------------
+; syscall Tracing
+; ---------------------------------------------
 tracesys:
 	; save EFA in case tracer wants the PC of traced task
 	; using ERET won't work since next-PC has already committed
@@ -459,10 +457,9 @@ tracesys_exit:
 	b   ret_from_exception ; NOT ret_from_system_call at is saves r0 which
 	; we'd done before calling post hook above
 
-;################### Break Point TRAP ##########################
-
-	; ======= (5b) Trap is due to Break-Point =========
-
+; ---------------------------------------------
+; Breakpoint TRAP
+; ---------------------------------------------
 trap_with_param:
 
 	; stop_pc info by gdb needs this info
@@ -490,36 +487,33 @@ trap_with_param:
 
 	b   ret_from_exception
 
-;##################### Trap Handling ##############################
-;
-; EV_Trap caused by TRAP_S and TRAP0 instructions.
-;------------------------------------------------------------------
-;   (1) System Calls
-;       :parameters in r0-r7.
-;       :r8 has the system call number
-;   (2) Break Points
-;------------------------------------------------------------------
+; ---------------------------------------------
+; syscall TRAP
+; ABI: (r0-r7) upto 8 args, (r8) syscall number
+; ---------------------------------------------
 
 ENTRY(EV_Trap)
 
 	EXCEPTION_PROLOGUE
 
-	;------- (4) What caused the Trap --------------
+	;============ TRAP 1   :breakpoints
 	lr     r10, [ecr]
 	bmsk.f 0, r10, 7
 	bnz    trap_with_param
 
-	; ======= (5a) Trap is due to System Call ========
+	;============ TRAP  (no param): syscall top level
 
+	; First return from Exception to pure K mode (Exception/IRQs renabled)
 	FAKE_RET_FROM_EXCPN
 
-	; If syscall tracing ongoing, invoke pre-pos-hooks
+	; If syscall tracing ongoing, invoke pre-post-hooks
 	GET_CURR_THR_INFO_FLAGS   r10
 	btst r10, TIF_SYSCALL_TRACE
 	bnz tracesys  ; this never comes back
 
-	;============ This is normal System Call case ==========
-	; Sys-call num shd not exceed the total system calls avail
+	;============ Normal syscall case
+
+	; syscall num shd not exceed the total system calls avail
 	cmp     r8,  NR_syscalls
 	mov.hi  r0, -ENOSYS
 	bhi     ret_from_system_call
-- 
1.9.1

[PATCH 12/19] ARC: entry.S: Ensure that restore_regs is local to compilation unit

[Vineet Gupta]

This fixes the possible link/relo errors, since restore_regs will be
provided by ISA code, but called from ARC common code.
The .L prefix reassures binutils that it will be in same compilation
unit.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index a07cec4688ce..5995b11181fc 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -554,7 +554,7 @@ resume_user_mode_begin:
 	; Fast Path return to user mode if no pending work
 	GET_CURR_THR_INFO_FLAGS   r9
 	and.f  0,  r9, _TIF_WORK_MASK
-	bz     restore_regs
+	bz     .Lrestore_regs
 
 	; --- (Slow Path #1) task preemption ---
 	bbit0  r9, TIF_NEED_RESCHED, .Lchk_pend_signals
@@ -613,11 +613,11 @@ resume_kernel_mode:
 	; Can't preempt if preemption disabled
 	GET_CURR_THR_INFO_FROM_SP   r10
 	ld  r8, [r10, THREAD_INFO_PREEMPT_COUNT]
-	brne  r8, 0, restore_regs
+	brne  r8, 0, .Lrestore_regs
 
 	; check if this task's NEED_RESCHED flag set
 	ld  r9, [r10, THREAD_INFO_FLAGS]
-	bbit0  r9, TIF_NEED_RESCHED, restore_regs
+	bbit0  r9, TIF_NEED_RESCHED, .Lrestore_regs
 
 	; Invoke PREEMPTION
 	bl      preempt_schedule_irq
@@ -633,7 +633,7 @@ resume_kernel_mode:
 ; IRQ shd definitely not happen between now and rtie
 ; All 2 entry points to here already disable interrupts
 
-restore_regs :
+.Lrestore_regs:
 
 	TRACE_ASM_IRQ_ENABLE
 
-- 
1.9.1

[PATCH 13/19] ARC: entry.S: split into ARCompact ISA specific, common bits

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry-compact.h | 306 +++++++++++++++++++++++++++
 arch/arc/include/asm/entry.h         | 300 +-------------------------
 arch/arc/kernel/Makefile             |   4 +-
 arch/arc/kernel/entry-compact.S      | 393 +++++++++++++++++++++++++++++++++++
 arch/arc/kernel/entry.S              | 389 +---------------------------------
 5 files changed, 711 insertions(+), 681 deletions(-)
 create mode 100644 arch/arc/include/asm/entry-compact.h
 create mode 100644 arch/arc/kernel/entry-compact.S

diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
new file mode 100644
index 000000000000..6c0a81b598d2
--- /dev/null
+++ b/arch/arc/include/asm/entry-compact.h
@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
+ *  Stack switching code can no longer reliably rely on the fact that
+ *  if we are NOT in user mode, stack is switched to kernel mode.
+ *  e.g. L2 IRQ interrupted a L1 ISR which had not yet completed
+ *  it's prologue including stack switching from user mode
+ *
+ * Vineetg: Aug 28th 2008: Bug #94984
+ *  -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap
+ *   Normally CPU does this automatically, however when doing FAKE rtie,
+ *   we also need to explicitly do this. The problem in macros
+ *   FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit
+ *   was being "CLEARED" rather then "SET". Actually "SET" clears ZOL context
+ *
+ * Vineetg: May 5th 2008
+ *  -Modified CALLEE_REG save/restore macros to handle the fact that
+ *      r25 contains the kernel current task ptr
+ *  - Defined Stack Switching Macro to be reused in all intr/excp hdlrs
+ *  - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the
+ *      address Write back load ld.ab instead of seperate ld/add instn
+ *
+ * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
+ */
+
+#ifndef __ASM_ARC_ENTRY_COMPACT_H
+#define __ASM_ARC_ENTRY_COMPACT_H
+
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>	/* For THREAD_SIZE */
+
+/*--------------------------------------------------------------
+ * Switch to Kernel Mode stack if SP points to User Mode stack
+ *
+ * Entry   : r9 contains pre-IRQ/exception/trap status32
+ * Exit    : SP is set to kernel mode stack pointer
+ *           If CURR_IN_REG, r25 set to "current" task pointer
+ * Clobbers: r9
+ *-------------------------------------------------------------*/
+
+.macro SWITCH_TO_KERNEL_STK
+
+	/* User Mode when this happened ? Yes: Proceed to switch stack */
+	bbit1   r9, STATUS_U_BIT, 88f
+
+	/* OK we were already in kernel mode when this event happened, thus can
+	 * assume SP is kernel mode SP. _NO_ need to do any stack switching
+	 */
+
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+	/* However....
+	 * If Level 2 Interrupts enabled, we may end up with a corner case:
+	 * 1. User Task executing
+	 * 2. L1 IRQ taken, ISR starts (CPU auto-switched to KERNEL mode)
+	 * 3. But before it could switch SP from USER to KERNEL stack
+	 *      a L2 IRQ "Interrupts" L1
+	 * Thay way although L2 IRQ happened in Kernel mode, stack is still
+	 * not switched.
+	 * To handle this, we may need to switch stack even if in kernel mode
+	 * provided SP has values in range of USER mode stack ( < 0x7000_0000 )
+	 */
+	brlo sp, VMALLOC_START, 88f
+
+	/* TODO: vineetg:
+	 * We need to be a bit more cautious here. What if a kernel bug in
+	 * L1 ISR, caused SP to go whaco (some small value which looks like
+	 * USER stk) and then we take L2 ISR.
+	 * Above brlo alone would treat it as a valid L1-L2 sceanrio
+	 * instead of shouting alound
+	 * The only feasible way is to make sure this L2 happened in
+	 * L1 prelogue ONLY i.e. ilink2 is less than a pre-set marker in
+	 * L1 ISR before it switches stack
+	 */
+
+#endif
+
+	/* Save Pre Intr/Exception KERNEL MODE SP on kernel stack
+	 * safe-keeping not really needed, but it keeps the epilogue code
+	 * (SP restore) simpler/uniform.
+	 */
+	b.d	66f
+	mov	r9, sp
+
+88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
+
+	GET_CURR_TASK_ON_CPU   r9
+
+	/* With current tsk in r9, get it's kernel mode stack base */
+	GET_TSK_STACK_BASE  r9, r9
+
+66:
+#ifdef CONFIG_ARC_CURR_IN_REG
+	/*
+	 * Treat r25 as scratch reg, save it on stack first
+	 * Load it with current task pointer
+	 */
+	st	r25, [r9, -4]
+	GET_CURR_TASK_ON_CPU   r25
+#endif
+
+	/* Save Pre Intr/Exception User SP on kernel stack */
+	st.a    sp, [r9, -16]	; Make room for orig_r0, ECR, user_r25
+
+	/* CAUTION:
+	 * SP should be set at the very end when we are done with everything
+	 * In case of 2 levels of interrupt we depend on value of SP to assume
+	 * that everything else is done (loading r25 etc)
+	 */
+
+	/* set SP to point to kernel mode stack */
+	mov sp, r9
+
+	/* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
+
+.endm
+
+/*------------------------------------------------------------
+ * "FAKE" a rtie to return from CPU Exception context
+ * This is to re-enable Exceptions within exception
+ * Look at EV_ProtV to see how this is actually used
+ *-------------------------------------------------------------*/
+
+.macro FAKE_RET_FROM_EXCPN
+
+	ld  r9, [sp, PT_status32]
+	bic r9, r9, (STATUS_U_MASK|STATUS_DE_MASK)
+	bset  r9, r9, STATUS_L_BIT
+	sr  r9, [erstatus]
+	mov r9, 55f
+	sr  r9, [eret]
+
+	rtie
+55:
+.endm
+
+/*--------------------------------------------------------------
+ * For early Exception/ISR Prologue, a core reg is temporarily needed to
+ * code the rest of prolog (stack switching). This is done by stashing
+ * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP).
+ *
+ * Before saving the full regfile - this reg is restored back, only
+ * to be saved again on kernel mode stack, as part of pt_regs.
+ *-------------------------------------------------------------*/
+.macro PROLOG_FREEUP_REG	reg, mem
+#ifdef CONFIG_SMP
+	sr  \reg, [ARC_REG_SCRATCH_DATA0]
+#else
+	st  \reg, [\mem]
+#endif
+.endm
+
+.macro PROLOG_RESTORE_REG	reg, mem
+#ifdef CONFIG_SMP
+	lr  \reg, [ARC_REG_SCRATCH_DATA0]
+#else
+	ld  \reg, [\mem]
+#endif
+.endm
+
+/*--------------------------------------------------------------
+ * Exception Entry prologue
+ * -Switches stack to K mode (if not already)
+ * -Saves the register file
+ *
+ * After this it is safe to call the "C" handlers
+ *-------------------------------------------------------------*/
+.macro EXCEPTION_PROLOGUE
+
+	/* Need at least 1 reg to code the early exception prologue */
+	PROLOG_FREEUP_REG r9, @ex_saved_reg1
+
+	/* U/K mode at time of exception (stack not switched if already K) */
+	lr  r9, [erstatus]
+
+	/* ARC700 doesn't provide auto-stack switching */
+	SWITCH_TO_KERNEL_STK
+
+	lr	r9, [ecr]
+	st      r9, [sp, 8]    /* ECR */
+	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
+
+	/* Restore r9 used to code the early prologue */
+	PROLOG_RESTORE_REG  r9, @ex_saved_reg1
+
+	SAVE_R0_TO_R12
+	PUSH	gp
+	PUSH	fp
+	PUSH	blink
+	PUSHAX	eret
+	PUSHAX	erstatus
+	PUSH	lp_count
+	PUSHAX	lp_end
+	PUSHAX	lp_start
+	PUSHAX	erbta
+.endm
+
+/*--------------------------------------------------------------
+ * Restore all registers used by system call or Exceptions
+ * SP should always be pointing to the next free stack element
+ * when entering this macro.
+ *
+ * NOTE:
+ *
+ * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg
+ * for memory load operations. If used in that way interrupts are deffered
+ * by hardware and that is not good.
+ *-------------------------------------------------------------*/
+.macro EXCEPTION_EPILOGUE
+	POPAX	erbta
+	POPAX	lp_start
+	POPAX	lp_end
+
+	POP	r9
+	mov	lp_count, r9	;LD to lp_count is not allowed
+
+	POPAX	erstatus
+	POPAX	eret
+	POP	blink
+	POP	fp
+	POP	gp
+	RESTORE_R12_TO_R0
+
+	ld  sp, [sp] /* restore original sp */
+	/* orig_r0, ECR, user_r25 skipped automatically */
+.endm
+
+/* Dummy ECR values for Interrupts */
+#define event_IRQ1		0x0031abcd
+#define event_IRQ2		0x0032abcd
+
+.macro INTERRUPT_PROLOGUE  LVL
+
+	/* free up r9 as scratchpad */
+	PROLOG_FREEUP_REG r9, @int\LVL\()_saved_reg
+
+	/* Which mode (user/kernel) was the system in when intr occured */
+	lr  r9, [status32_l\LVL\()]
+
+	SWITCH_TO_KERNEL_STK
+
+	/* restore original r9 */
+	PROLOG_RESTORE_REG  r9, @int\LVL\()_saved_reg
+
+	/* now we are ready to save the remaining context */
+	st	0x003\LVL\()abcd, [sp, 8]    /* Dummy ECR */
+	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
+
+	SAVE_R0_TO_R12
+	PUSH	gp
+	PUSH	fp
+	PUSH	blink
+	PUSH	ilink\LVL\()
+	PUSHAX	status32_l\LVL\()
+	PUSH	lp_count
+	PUSHAX	lp_end
+	PUSHAX	lp_start
+	PUSHAX	bta_l\LVL\()
+.endm
+
+/*--------------------------------------------------------------
+ * Restore all registers used by interrupt handlers.
+ *
+ * NOTE:
+ *
+ * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg
+ * for memory load operations. If used in that way interrupts are deffered
+ * by hardware and that is not good.
+ *-------------------------------------------------------------*/
+.macro INTERRUPT_EPILOGUE  LVL
+	POPAX	bta_l\LVL\()
+	POPAX	lp_start
+	POPAX	lp_end
+
+	POP	r9
+	mov	lp_count, r9	;LD to lp_count is not allowed
+
+	POPAX	status32_l\LVL\()
+	POP	ilink\LVL\()
+	POP	blink
+	POP	fp
+	POP	gp
+	RESTORE_R12_TO_R0
+
+	ld  sp, [sp] /* restore original sp */
+	/* orig_r0, ECR, user_r25 skipped automatically */
+.endm
+
+/* Get thread_info of "current" tsk */
+.macro GET_CURR_THR_INFO_FROM_SP  reg
+	bic \reg, sp, (THREAD_SIZE - 1)
+.endm
+
+/* Get CPU-ID of this core */
+.macro  GET_CPU_ID  reg
+	lr  \reg, [identity]
+	lsr \reg, \reg, 8
+	bmsk \reg, \reg, 7
+.endm
+
+#endif  /* __ASM_ARC_ENTRY_COMPACT_H */
diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index c976b54c9b07..f61032c53d51 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -1,45 +1,23 @@
 /*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
- *  Stack switching code can no longer reliably rely on the fact that
- *  if we are NOT in user mode, stack is switched to kernel mode.
- *  e.g. L2 IRQ interrupted a L1 ISR which had not yet completed
- *  it's prologue including stack switching from user mode
- *
- * Vineetg: Aug 28th 2008: Bug #94984
- *  -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap
- *   Normally CPU does this automatically, however when doing FAKE rtie,
- *   we also need to explicitly do this. The problem in macros
- *   FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit
- *   was being "CLEARED" rather then "SET". Actually "SET" clears ZOL context
- *
- * Vineetg: May 5th 2008
- *  -Modified CALLEE_REG save/restore macros to handle the fact that
- *      r25 contains the kernel current task ptr
- *  - Defined Stack Switching Macro to be reused in all intr/excp hdlrs
- *  - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the
- *      address Write back load ld.ab instead of seperate ld/add instn
- *
- * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
  */
 
 #ifndef __ASM_ARC_ENTRY_H
 #define __ASM_ARC_ENTRY_H
 
-#ifdef __ASSEMBLY__
 #include <asm/unistd.h>		/* For NR_syscalls defination */
-#include <asm/asm-offsets.h>
 #include <asm/arcregs.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>	/* For VMALLOC_START */
-#include <asm/thread_info.h>	/* For THREAD_SIZE */
 #include <asm/mmu.h>
 
+#include <asm/entry-compact.h>	/* ISA specific bits */
+
 /* Note on the LD/ST addr modes with addr reg wback
  *
  * LD.a same as LD.aw
@@ -240,117 +218,6 @@
 
 .endm
 
-/*--------------------------------------------------------------
- * Switch to Kernel Mode stack if SP points to User Mode stack
- *
- * Entry   : r9 contains pre-IRQ/exception/trap status32
- * Exit    : SP is set to kernel mode stack pointer
- *           If CURR_IN_REG, r25 set to "current" task pointer
- * Clobbers: r9
- *-------------------------------------------------------------*/
-
-.macro SWITCH_TO_KERNEL_STK
-
-	/* User Mode when this happened ? Yes: Proceed to switch stack */
-	bbit1   r9, STATUS_U_BIT, 88f
-
-	/* OK we were already in kernel mode when this event happened, thus can
-	 * assume SP is kernel mode SP. _NO_ need to do any stack switching
-	 */
-
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-	/* However....
-	 * If Level 2 Interrupts enabled, we may end up with a corner case:
-	 * 1. User Task executing
-	 * 2. L1 IRQ taken, ISR starts (CPU auto-switched to KERNEL mode)
-	 * 3. But before it could switch SP from USER to KERNEL stack
-	 *      a L2 IRQ "Interrupts" L1
-	 * Thay way although L2 IRQ happened in Kernel mode, stack is still
-	 * not switched.
-	 * To handle this, we may need to switch stack even if in kernel mode
-	 * provided SP has values in range of USER mode stack ( < 0x7000_0000 )
-	 */
-	brlo sp, VMALLOC_START, 88f
-
-	/* TODO: vineetg:
-	 * We need to be a bit more cautious here. What if a kernel bug in
-	 * L1 ISR, caused SP to go whaco (some small value which looks like
-	 * USER stk) and then we take L2 ISR.
-	 * Above brlo alone would treat it as a valid L1-L2 sceanrio
-	 * instead of shouting alound
-	 * The only feasible way is to make sure this L2 happened in
-	 * L1 prelogue ONLY i.e. ilink2 is less than a pre-set marker in
-	 * L1 ISR before it switches stack
-	 */
-
-#endif
-
-	/* Save Pre Intr/Exception KERNEL MODE SP on kernel stack
-	 * safe-keeping not really needed, but it keeps the epilogue code
-	 * (SP restore) simpler/uniform.
-	 */
-	b.d	66f
-	mov	r9, sp
-
-88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
-
-	GET_CURR_TASK_ON_CPU   r9
-
-	/* With current tsk in r9, get it's kernel mode stack base */
-	GET_TSK_STACK_BASE  r9, r9
-
-66:
-#ifdef CONFIG_ARC_CURR_IN_REG
-	/*
-	 * Treat r25 as scratch reg, save it on stack first
-	 * Load it with current task pointer
-	 */
-	st	r25, [r9, -4]
-	GET_CURR_TASK_ON_CPU   r25
-#endif
-
-	/* Save Pre Intr/Exception User SP on kernel stack */
-	st.a    sp, [r9, -16]	; Make room for orig_r0, ECR, user_r25
-
-	/* CAUTION:
-	 * SP should be set at the very end when we are done with everything
-	 * In case of 2 levels of interrupt we depend on value of SP to assume
-	 * that everything else is done (loading r25 etc)
-	 */
-
-	/* set SP to point to kernel mode stack */
-	mov sp, r9
-
-	/* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
-
-.endm
-
-/*------------------------------------------------------------
- * "FAKE" a rtie to return from CPU Exception context
- * This is to re-enable Exceptions within exception
- * Look at EV_ProtV to see how this is actually used
- *-------------------------------------------------------------*/
-
-.macro FAKE_RET_FROM_EXCPN
-
-	ld  r9, [sp, PT_status32]
-	bic  r9, r9, (STATUS_U_MASK|STATUS_DE_MASK)
-	bset r9, r9, STATUS_L_BIT
-	sr  r9, [erstatus]
-	mov r9, 55f
-	sr  r9, [eret]
-
-	rtie
-55:
-.endm
-
-/*
- * @reg [OUT] &thread_info of "current"
- */
-.macro GET_CURR_THR_INFO_FROM_SP  reg
-	bic \reg, sp, (THREAD_SIZE - 1)
-.endm
-
 /*
  * @reg [OUT] thread_info->flags of "current"
  */
@@ -359,165 +226,6 @@
 	ld  \reg, [\reg, THREAD_INFO_FLAGS]
 .endm
 
-/*--------------------------------------------------------------
- * For early Exception/ISR Prologue, a core reg is temporarily needed to
- * code the rest of prolog (stack switching). This is done by stashing
- * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP).
- *
- * Before saving the full regfile - this reg is restored back, only
- * to be saved again on kernel mode stack, as part of pt_regs.
- *-------------------------------------------------------------*/
-.macro PROLOG_FREEUP_REG	reg, mem
-#ifdef CONFIG_SMP
-	sr  \reg, [ARC_REG_SCRATCH_DATA0]
-#else
-	st  \reg, [\mem]
-#endif
-.endm
-
-.macro PROLOG_RESTORE_REG	reg, mem
-#ifdef CONFIG_SMP
-	lr  \reg, [ARC_REG_SCRATCH_DATA0]
-#else
-	ld  \reg, [\mem]
-#endif
-.endm
-
-/*--------------------------------------------------------------
- * Exception Entry prologue
- * -Switches stack to K mode (if not already)
- * -Saves the register file
- *
- * After this it is safe to call the "C" handlers
- *-------------------------------------------------------------*/
-.macro EXCEPTION_PROLOGUE
-
-	/* Need at least 1 reg to code the early exception prologue */
-	PROLOG_FREEUP_REG r9, @ex_saved_reg1
-
-	/* U/K mode at time of exception (stack not switched if already K) */
-	lr  r9, [erstatus]
-
-	/* ARC700 doesn't provide auto-stack switching */
-	SWITCH_TO_KERNEL_STK
-
-	lr	r9, [ecr]
-	st      r9, [sp, 8]    /* ECR */
-	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
-
-	/* Restore r9 used to code the early prologue */
-	PROLOG_RESTORE_REG  r9, @ex_saved_reg1
-
-	SAVE_R0_TO_R12
-	PUSH	gp
-	PUSH	fp
-	PUSH	blink
-	PUSHAX	eret
-	PUSHAX	erstatus
-	PUSH	lp_count
-	PUSHAX	lp_end
-	PUSHAX	lp_start
-	PUSHAX	erbta
-.endm
-
-/*--------------------------------------------------------------
- * Restore all registers used by system call or Exceptions
- * SP should always be pointing to the next free stack element
- * when entering this macro.
- *
- * NOTE:
- *
- * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg
- * for memory load operations. If used in that way interrupts are deffered
- * by hardware and that is not good.
- *-------------------------------------------------------------*/
-.macro EXCEPTION_EPILOGUE
-	POPAX	erbta
-	POPAX	lp_start
-	POPAX	lp_end
-
-	POP	r9
-	mov	lp_count, r9	;LD to lp_count is not allowed
-
-	POPAX	erstatus
-	POPAX	eret
-	POP	blink
-	POP	fp
-	POP	gp
-	RESTORE_R12_TO_R0
-
-	ld  sp, [sp] /* restore original sp */
-	/* orig_r0, ECR, user_r25 skipped automatically */
-.endm
-
-/* Dummy ECR values for Interrupts */
-#define event_IRQ1		0x0031abcd
-#define event_IRQ2		0x0032abcd
-
-.macro INTERRUPT_PROLOGUE  LVL
-
-	/* free up r9 as scratchpad */
-	PROLOG_FREEUP_REG r9, @int\LVL\()_saved_reg
-
-	/* Which mode (user/kernel) was the system in when intr occured */
-	lr  r9, [status32_l\LVL\()]
-
-	SWITCH_TO_KERNEL_STK
-
-	/* restore original r9 */
-	PROLOG_RESTORE_REG  r9, @int\LVL\()_saved_reg
-
-	/* now we are ready to save the remaining context */
-	st      0x003\LVL\()abcd, [sp, 8]    /* Dummy ECR */
-	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
-
-	SAVE_R0_TO_R12
-	PUSH	gp
-	PUSH	fp
-	PUSH	blink
-	PUSH	ilink\LVL\()
-	PUSHAX	status32_l\LVL\()
-	PUSH	lp_count
-	PUSHAX	lp_end
-	PUSHAX	lp_start
-	PUSHAX	bta_l\LVL\()
-.endm
-
-/*--------------------------------------------------------------
- * Restore all registers used by interrupt handlers.
- *
- * NOTE:
- *
- * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg
- * for memory load operations. If used in that way interrupts are deffered
- * by hardware and that is not good.
- *-------------------------------------------------------------*/
-.macro INTERRUPT_EPILOGUE  LVL
-	POPAX	bta_l\LVL\()
-	POPAX	lp_start
-	POPAX	lp_end
-
-	POP	r9
-	mov	lp_count, r9	;LD to lp_count is not allowed
-
-	POPAX	status32_l\LVL\()
-	POP	ilink\LVL\()
-	POP	blink
-	POP	fp
-	POP	gp
-	RESTORE_R12_TO_R0
-
-	ld  sp, [sp] /* restore original sp */
-	/* orig_r0, ECR, user_r25 skipped automatically */
-.endm
-
-/* Get CPU-ID of this core */
-.macro  GET_CPU_ID  reg
-	lr  \reg, [identity]
-	lsr \reg, \reg, 8
-	bmsk \reg, \reg, 7
-.endm
-
 #ifdef CONFIG_SMP
 
 /*-------------------------------------------------
@@ -586,6 +294,4 @@
 
 #endif	/* CONFIG_ARC_CURR_IN_REG */
 
-#endif  /* __ASSEMBLY__ */
-
 #endif  /* __ASM_ARC_ENTRY_H */
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index 113f2033da9f..024a63e90b72 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -8,9 +8,9 @@
 # Pass UTS_MACHINE for user_regset definition
 CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
-obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o
+obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o
 obj-y	+= signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o clk.o
-obj-y	+= devtree.o
+obj-y	+= entry-compact.o
 
 obj-$(CONFIG_MODULES)			+= arcksyms.o module.o
 obj-$(CONFIG_SMP) 			+= smp.o
diff --git a/arch/arc/kernel/entry-compact.S b/arch/arc/kernel/entry-compact.S
new file mode 100644
index 000000000000..bf611ec9a017
--- /dev/null
+++ b/arch/arc/kernel/entry-compact.S
@@ -0,0 +1,393 @@
+/*
+ * Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARCompact ISA
+ *
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * vineetg: May 2011
+ *  -Userspace unaligned access emulation
+ *
+ * vineetg: Feb 2011 (ptrace low level code fixes)
+ *  -traced syscall return code (r0) was not saved into pt_regs for restoring
+ *   into user reg-file when traded task rets to user space.
+ *  -syscalls needing arch-wrappers (mainly for passing sp as pt_regs)
+ *   were not invoking post-syscall trace hook (jumping directly into
+ *   ret_from_system_call)
+ *
+ * vineetg: Nov 2010:
+ *  -Vector table jumps (@8 bytes) converted into branches (@4 bytes)
+ *  -To maintain the slot size of 8 bytes/vector, added nop, which is
+ *   not executed at runtime.
+ *
+ * vineetg: Nov 2009 (Everything needed for TIF_RESTORE_SIGMASK)
+ *  -do_signal()invoked upon TIF_RESTORE_SIGMASK as well
+ *  -Wrappers for sys_{,rt_}sigsuspend() nolonger needed as they don't
+ *   need ptregs anymore
+ *
+ * Vineetg: Oct 2009
+ *  -In a rare scenario, Process gets a Priv-V exception and gets scheduled
+ *   out. Since we don't do FAKE RTIE for Priv-V, CPU excpetion state remains
+ *   active (AE bit enabled).  This causes a double fault for a subseq valid
+ *   exception. Thus FAKE RTIE needed in low level Priv-Violation handler.
+ *   Instr Error could also cause similar scenario, so same there as well.
+ *
+ * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
+ *
+ * Vineetg: Aug 28th 2008: Bug #94984
+ *  -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap
+ *   Normally CPU does this automatically, however when doing FAKE rtie,
+ *   we need to explicitly do this. The problem in macros
+ *   FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit
+ *   was being "CLEARED" rather then "SET". Since it is Loop INHIBIT Bit,
+ *   setting it and not clearing it clears ZOL context
+ *
+ * Vineetg: May 16th, 2008
+ *  - r25 now contains the Current Task when in kernel
+ *
+ * Vineetg: Dec 22, 2007
+ *    Minor Surgery of Low Level ISR to make it SMP safe
+ *    - MMU_SCRATCH0 Reg used for freeing up r9 in Level 1 ISR
+ *    - _current_task is made an array of NR_CPUS
+ *    - Access of _current_task wrapped inside a macro so that if hardware
+ *       team agrees for a dedicated reg, no other code is touched
+ *
+ * Amit Bhor, Rahul Trivedi, Kanika Nema, Sameer Dhavale : Codito Tech 2004
+ */
+
+#include <linux/errno.h>
+#include <linux/linkage.h>	/* {EXTRY,EXIT} */
+#include <asm/entry.h>
+#include <asm/irqflags.h>
+
+	.cpu A7
+
+;############################ Vector Table #################################
+
+.macro VECTOR  lbl
+#if 1   /* Just in case, build breaks */
+	j   \lbl
+#else
+	b   \lbl
+	nop
+#endif
+.endm
+
+	.section .vector, "ax",@progbits
+	.align 4
+
+/* Each entry in the vector table must occupy 2 words. Since it is a jump
+ * across sections (.vector to .text) we are gauranteed that 'j somewhere'
+ * will use the 'j limm' form of the intrsuction as long as somewhere is in
+ * a section other than .vector.
+ */
+
+; ********* Critical System Events **********************
+VECTOR   res_service             ; 0x0, Restart Vector  (0x0)
+VECTOR   mem_service             ; 0x8, Mem exception   (0x1)
+VECTOR   instr_service           ; 0x10, Instrn Error   (0x2)
+
+; ******************** Device ISRs **********************
+#ifdef CONFIG_ARC_IRQ3_LV2
+VECTOR   handle_interrupt_level2
+#else
+VECTOR   handle_interrupt_level1
+#endif
+
+VECTOR   handle_interrupt_level1
+
+#ifdef CONFIG_ARC_IRQ5_LV2
+VECTOR   handle_interrupt_level2
+#else
+VECTOR   handle_interrupt_level1
+#endif
+
+#ifdef CONFIG_ARC_IRQ6_LV2
+VECTOR   handle_interrupt_level2
+#else
+VECTOR   handle_interrupt_level1
+#endif
+
+.rept   25
+VECTOR   handle_interrupt_level1 ; Other devices
+.endr
+
+/* FOR ARC600: timer = 0x3, uart = 0x8, emac = 0x10 */
+
+; ******************** Exceptions **********************
+VECTOR   EV_MachineCheck         ; 0x100, Fatal Machine check   (0x20)
+VECTOR   EV_TLBMissI             ; 0x108, Intruction TLB miss   (0x21)
+VECTOR   EV_TLBMissD             ; 0x110, Data TLB miss         (0x22)
+VECTOR   EV_TLBProtV             ; 0x118, Protection Violation  (0x23)
+				 ;         or Misaligned Access
+VECTOR   EV_PrivilegeV           ; 0x120, Privilege Violation   (0x24)
+VECTOR   EV_Trap                 ; 0x128, Trap exception        (0x25)
+VECTOR   EV_Extension            ; 0x130, Extn Intruction Excp  (0x26)
+
+.rept   24
+VECTOR   reserved                ; Reserved Exceptions
+.endr
+
+
+;##################### Scratch Mem for IRQ stack switching #############
+
+ARCFP_DATA int1_saved_reg
+	.align 32
+	.type   int1_saved_reg, @object
+	.size   int1_saved_reg, 4
+int1_saved_reg:
+	.zero 4
+
+/* Each Interrupt level needs its own scratch */
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+
+ARCFP_DATA int2_saved_reg
+	.type   int2_saved_reg, @object
+	.size   int2_saved_reg, 4
+int2_saved_reg:
+	.zero 4
+
+#endif
+
+; ---------------------------------------------
+	.section .text, "ax",@progbits
+
+res_service:		; processor restart
+	flag    0x1     ; not implemented
+	nop
+	nop
+
+reserved:		; processor restart
+	rtie            ; jump to processor initializations
+
+;##################### Interrupt Handling ##############################
+
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+; ---------------------------------------------
+;  Level 2 ISR: Can interrupt a Level 1 ISR
+; ---------------------------------------------
+ENTRY(handle_interrupt_level2)
+
+	INTERRUPT_PROLOGUE 2
+
+	;------------------------------------------------------
+	; if L2 IRQ interrupted a L1 ISR, disable preemption
+	;------------------------------------------------------
+
+	ld r9, [sp, PT_status32]        ; get statu32_l2 (saved in pt_regs)
+	bbit0 r9, STATUS_A1_BIT, 1f     ; L1 not active when L2 IRQ, so normal
+
+	; A1 is set in status32_l2
+	; bump thread_info->preempt_count (Disable preemption)
+	GET_CURR_THR_INFO_FROM_SP   r10
+	ld      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+	add     r9, r9, 1
+	st      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+
+1:
+	;------------------------------------------------------
+	; setup params for Linux common ISR and invoke it
+	;------------------------------------------------------
+	lr  r0, [icause2]
+	and r0, r0, 0x1f
+
+	bl.d  @arch_do_IRQ
+	mov r1, sp
+
+	mov r8,0x2
+	sr r8, [AUX_IRQ_LV12]       ; clear bit in Sticky Status Reg
+
+	b   ret_from_exception
+
+END(handle_interrupt_level2)
+
+#endif
+
+; ---------------------------------------------
+;  Level 1 ISR
+; ---------------------------------------------
+ENTRY(handle_interrupt_level1)
+
+	INTERRUPT_PROLOGUE 1
+
+	lr  r0, [icause1]
+	and r0, r0, 0x1f
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	; icause1 needs to be read early, before calling tracing, which
+	; can clobber scratch regs, hence use of stack to stash it
+	push r0
+	TRACE_ASM_IRQ_DISABLE
+	pop  r0
+#endif
+
+	bl.d  @arch_do_IRQ
+	mov r1, sp
+
+	mov r8,0x1
+	sr r8, [AUX_IRQ_LV12]       ; clear bit in Sticky Status Reg
+
+	b   ret_from_exception
+END(handle_interrupt_level1)
+
+;################### Non TLB Exception Handling #############################
+
+; ---------------------------------------------
+; Protection Violation Exception Handler
+; ---------------------------------------------
+
+ENTRY(EV_TLBProtV)
+
+	EXCEPTION_PROLOGUE
+
+	lr  r2, [ecr]
+	lr  r0, [efa]	; Faulting Data address (not part of pt_regs saved above)
+
+	; Exception auto-disables further Intr/exceptions.
+	; Re-enable them by pretending to return from exception
+	; (so rest of handler executes in pure K mode)
+
+	FAKE_RET_FROM_EXCPN
+
+	mov   r1, sp	; Handle to pt_regs
+
+	;------ (5) Type of Protection Violation? ----------
+	;
+	; ProtV Hardware Exception is triggered for Access Faults of 2 types
+	;   -Access Violaton	: 00_23_(00|01|02|03)_00
+	;			         x  r  w  r+w
+	;   -Unaligned Access	: 00_23_04_00
+	;
+	bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f
+
+	;========= (6a) Access Violation Processing ========
+	bl  do_page_fault
+	b   ret_from_exception
+
+	;========== (6b) Non aligned access ============
+4:
+
+	SAVE_CALLEE_SAVED_USER
+	mov r2, sp              ; callee_regs
+
+	bl  do_misaligned_access
+
+	; TBD: optimize - do this only if a callee reg was involved
+	; either a dst of emulated LD/ST or src with address-writeback
+	RESTORE_CALLEE_SAVED_USER
+
+	b   ret_from_exception
+
+END(EV_TLBProtV)
+
+; Wrapper for Linux page fault handler called from EV_TLBMiss*
+; Very similar to ProtV handler case (6a) above, but avoids the extra checks
+; for Misaligned access
+;
+ENTRY(call_do_page_fault)
+
+	EXCEPTION_PROLOGUE
+	lr  r0, [efa]	; Faulting Data address
+	mov   r1, sp
+	FAKE_RET_FROM_EXCPN
+
+	mov blink, ret_from_exception
+	b  do_page_fault
+
+END(call_do_page_fault)
+
+;############# Common Handlers for ARCompact and ARCv2 ##############
+
+#include "entry.S"
+
+;############# Return from Intr/Excp/Trap (ARC Specifics) ##############
+;
+; Restore the saved sys context (common exit-path for EXCPN/IRQ/Trap)
+; IRQ shd definitely not happen between now and rtie
+; All 2 entry points to here already disable interrupts
+
+.Lrestore_regs:
+
+	TRACE_ASM_IRQ_ENABLE
+
+	lr	r10, [status32]
+
+	; Restore REG File. In case multiple Events outstanding,
+	; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None
+	; Note that we use realtime STATUS32 (not pt_regs->status32) to
+	; decide that.
+
+	; if Returning from Exception
+	bbit0  r10, STATUS_AE_BIT, not_exception
+	EXCEPTION_EPILOGUE
+	rtie
+
+	; Not Exception so maybe Interrupts (Level 1 or 2)
+
+not_exception:
+
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+
+	; Level 2 interrupt return Path - from hardware standpoint
+	bbit0  r10, STATUS_A2_BIT, not_level2_interrupt
+
+	;------------------------------------------------------------------
+	; However the context returning might not have taken L2 intr itself
+	; e.g. Task'A' user-code -> L2 intr -> schedule -> 'B' user-code ret
+	; Special considerations needed for the context which took L2 intr
+
+	ld   r9, [sp, PT_event]        ; Ensure this is L2 intr context
+	brne r9, event_IRQ2, 149f
+
+	;------------------------------------------------------------------
+	; if L2 IRQ interrupted an L1 ISR,  we'd disabled preemption earlier
+	; so that sched doesn't move to new task, causing L1 to be delayed
+	; undeterministically. Now that we've achieved that, let's reset
+	; things to what they were, before returning from L2 context
+	;----------------------------------------------------------------
+
+	ld r9, [sp, PT_status32]       ; get statu32_l2 (saved in pt_regs)
+	bbit0 r9, STATUS_A1_BIT, 149f  ; L1 not active when L2 IRQ, so normal
+
+	; decrement thread_info->preempt_count (re-enable preemption)
+	GET_CURR_THR_INFO_FROM_SP   r10
+	ld      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+
+	; paranoid check, given A1 was active when A2 happened, preempt count
+	; must not be 0 because we would have incremented it.
+	; If this does happen we simply HALT as it means a BUG !!!
+	cmp     r9, 0
+	bnz     2f
+	flag 1
+
+2:
+	sub     r9, r9, 1
+	st      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+
+149:
+	;return from level 2
+	INTERRUPT_EPILOGUE 2
+debug_marker_l2:
+	rtie
+
+not_level2_interrupt:
+
+#endif
+
+	bbit0  r10, STATUS_A1_BIT, not_level1_interrupt
+
+	;return from level 1
+	INTERRUPT_EPILOGUE 1
+debug_marker_l1:
+	rtie
+
+not_level1_interrupt:
+
+	;this case is for syscalls or Exceptions (with fake rtie)
+
+	EXCEPTION_EPILOGUE
+debug_marker_syscall:
+	rtie
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 5995b11181fc..75cdc56351d9 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -1,60 +1,13 @@
 /*
- * Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARC
+ * Common Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARC
+ * (included from entry-<isa>.S
  *
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- * vineetg: May 2011
- *  -Userspace unaligned access emulation
- *
- * vineetg: Feb 2011 (ptrace low level code fixes)
- *  -traced syscall return code (r0) was not saved into pt_regs for restoring
- *   into user reg-file when traded task rets to user space.
- *  -syscalls needing arch-wrappers (mainly for passing sp as pt_regs)
- *   were not invoking post-syscall trace hook (jumping directly into
- *   ret_from_system_call)
- *
- * vineetg: Nov 2010:
- *  -Vector table jumps (@8 bytes) converted into branches (@4 bytes)
- *  -To maintain the slot size of 8 bytes/vector, added nop, which is
- *   not executed at runtime.
- *
- * vineetg: Nov 2009 (Everything needed for TIF_RESTORE_SIGMASK)
- *  -do_signal()invoked upon TIF_RESTORE_SIGMASK as well
- *  -Wrappers for sys_{,rt_}sigsuspend() nolonger needed as they don't
- *   need ptregs anymore
- *
- * Vineetg: Oct 2009
- *  -In a rare scenario, Process gets a Priv-V exception and gets scheduled
- *   out. Since we don't do FAKE RTIE for Priv-V, CPU excpetion state remains
- *   active (AE bit enabled).  This causes a double fault for a subseq valid
- *   exception. Thus FAKE RTIE needed in low level Priv-Violation handler.
- *   Instr Error could also cause similar scenario, so same there as well.
- *
- * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
- *
- * Vineetg: Aug 28th 2008: Bug #94984
- *  -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap
- *   Normally CPU does this automatically, however when doing FAKE rtie,
- *   we need to explicitly do this. The problem in macros
- *   FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit
- *   was being "CLEARED" rather then "SET". Since it is Loop INHIBIT Bit,
- *   setting it and not clearing it clears ZOL context
- *
- * Vineetg: May 16th, 2008
- *  - r25 now contains the Current Task when in kernel
- *
- * Vineetg: Dec 22, 2007
- *    Minor Surgery of Low Level ISR to make it SMP safe
- *    - MMU_SCRATCH0 Reg used for freeing up r9 in Level 1 ISR
- *    - _current_task is made an array of NR_CPUS
- *    - Access of _current_task wrapped inside a macro so that if hardware
- *       team agrees for a dedicated reg, no other code is touched
- *
- * Amit Bhor, Rahul Trivedi, Kanika Nema, Sameer Dhavale : Codito Tech 2004
  */
 
 /*------------------------------------------------------------------
@@ -67,187 +20,10 @@
  *  Global Pointer (gp)                 r26
  *  Frame Pointer (fp)                  r27
  *  Stack Pointer (sp)                  r28
- *  Interrupt link register (ilink1)    r29
- *  Interrupt link register (ilink2)    r30
  *  Branch link register (blink)        r31
  *------------------------------------------------------------------
  */
 
-	.cpu A7
-
-;############################ Vector Table #################################
-
-.macro VECTOR  lbl
-#if 1   /* Just in case, build breaks */
-	j   \lbl
-#else
-	b   \lbl
-	nop
-#endif
-.endm
-
-	.section .vector, "ax",@progbits
-	.align 4
-
-/* Each entry in the vector table must occupy 2 words. Since it is a jump
- * across sections (.vector to .text) we are gauranteed that 'j somewhere'
- * will use the 'j limm' form of the intrsuction as long as somewhere is in
- * a section other than .vector.
- */
-
-; ********* Critical System Events **********************
-VECTOR   res_service             ; 0x0, Restart Vector  (0x0)
-VECTOR   mem_service             ; 0x8, Mem exception   (0x1)
-VECTOR   instr_service           ; 0x10, Instrn Error   (0x2)
-
-; ******************** Device ISRs **********************
-#ifdef CONFIG_ARC_IRQ3_LV2
-VECTOR   handle_interrupt_level2
-#else
-VECTOR   handle_interrupt_level1
-#endif
-
-VECTOR   handle_interrupt_level1
-
-#ifdef CONFIG_ARC_IRQ5_LV2
-VECTOR   handle_interrupt_level2
-#else
-VECTOR   handle_interrupt_level1
-#endif
-
-#ifdef CONFIG_ARC_IRQ6_LV2
-VECTOR   handle_interrupt_level2
-#else
-VECTOR   handle_interrupt_level1
-#endif
-
-.rept   25
-VECTOR   handle_interrupt_level1 ; Other devices
-.endr
-
-/* FOR ARC600: timer = 0x3, uart = 0x8, emac = 0x10 */
-
-; ******************** Exceptions **********************
-VECTOR   EV_MachineCheck         ; 0x100, Fatal Machine check   (0x20)
-VECTOR   EV_TLBMissI             ; 0x108, Intruction TLB miss   (0x21)
-VECTOR   EV_TLBMissD             ; 0x110, Data TLB miss         (0x22)
-VECTOR   EV_TLBProtV             ; 0x118, Protection Violation  (0x23)
-				 ;         or Misaligned Access
-VECTOR   EV_PrivilegeV           ; 0x120, Privilege Violation   (0x24)
-VECTOR   EV_Trap                 ; 0x128, Trap exception        (0x25)
-VECTOR   EV_Extension            ; 0x130, Extn Intruction Excp  (0x26)
-
-.rept   24
-VECTOR   reserved                ; Reserved Exceptions
-.endr
-
-#include <linux/linkage.h>   /* {EXTRY,EXIT} */
-#include <asm/entry.h>       /* SAVE_ALL_{INT1,INT2,SYS...} */
-#include <asm/errno.h>
-#include <asm/arcregs.h>
-#include <asm/irqflags.h>
-
-;##################### Scratch Mem for IRQ stack switching #############
-
-ARCFP_DATA int1_saved_reg
-	.align 32
-	.type   int1_saved_reg, @object
-	.size   int1_saved_reg, 4
-int1_saved_reg:
-	.zero 4
-
-/* Each Interrupt level needs its own scratch */
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-
-ARCFP_DATA int2_saved_reg
-	.type   int2_saved_reg, @object
-	.size   int2_saved_reg, 4
-int2_saved_reg:
-	.zero 4
-
-#endif
-
-; ---------------------------------------------
-	.section .text, "ax",@progbits
-
-res_service:		; processor restart
-	flag    0x1     ; not implemented
-	nop
-	nop
-
-reserved:		; processor restart
-	rtie            ; jump to processor initializations
-
-;##################### Interrupt Handling ##############################
-
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-; ---------------------------------------------
-;  Level 2 ISR: Can interrupt a Level 1 ISR
-; ---------------------------------------------
-ENTRY(handle_interrupt_level2)
-
-	INTERRUPT_PROLOGUE 2
-
-	;------------------------------------------------------
-	; if L2 IRQ interrupted a L1 ISR, disable preemption
-	;------------------------------------------------------
-
-	ld r9, [sp, PT_status32]        ; get statu32_l2 (saved in pt_regs)
-	bbit0 r9, STATUS_A1_BIT, 1f     ; L1 not active when L2 IRQ, so normal
-
-	; A1 is set in status32_l2
-	; bump thread_info->preempt_count (Disable preemption)
-	GET_CURR_THR_INFO_FROM_SP   r10
-	ld      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-	add     r9, r9, 1
-	st      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-
-1:
-	;------------------------------------------------------
-	; setup params for Linux common ISR and invoke it
-	;------------------------------------------------------
-	lr  r0, [icause2]
-	and r0, r0, 0x1f
-
-	bl.d  @arch_do_IRQ
-	mov r1, sp
-
-	mov r8,0x2
-	sr r8, [AUX_IRQ_LV12]       ; clear bit in Sticky Status Reg
-
-	b   ret_from_exception
-
-END(handle_interrupt_level2)
-
-#endif
-
-; ---------------------------------------------
-;  Level 1 ISR
-; ---------------------------------------------
-ENTRY(handle_interrupt_level1)
-
-	INTERRUPT_PROLOGUE 1
-
-	lr  r0, [icause1]
-	and r0, r0, 0x1f
-
-#ifdef CONFIG_TRACE_IRQFLAGS
-	; icause1 needs to be read early, before calling tracing, which
-	; can clobber scratch regs, hence use of stack to stash it
-	push r0
-	TRACE_ASM_IRQ_DISABLE
-	pop  r0
-#endif
-
-	bl.d  @arch_do_IRQ
-	mov r1, sp
-
-	mov r8,0x1
-	sr r8, [AUX_IRQ_LV12]       ; clear bit in Sticky Status Reg
-
-	b   ret_from_exception
-END(handle_interrupt_level1)
-
 ;################### Non TLB Exception Handling #############################
 
 ; ---------------------------------------------
@@ -315,70 +91,6 @@ ENTRY(EV_MachineCheck)
 END(EV_MachineCheck)
 
 ; ---------------------------------------------
-; Protection Violation Exception Handler
-; ---------------------------------------------
-
-ENTRY(EV_TLBProtV)
-
-	EXCEPTION_PROLOGUE
-
-	lr  r2, [ecr]
-	lr  r0, [efa]	; Faulting Data address (not part of pt_regs saved above)
-
-	; Exception auto-disables further Intr/exceptions.
-	; Re-enable them by pretending to return from exception
-	; (so rest of handler executes in pure K mode)
-
-	FAKE_RET_FROM_EXCPN
-
-	mov   r1, sp	; Handle to pt_regs
-
-	;------ (5) Type of Protection Violation? ----------
-	;
-	; ProtV Hardware Exception is triggered for Access Faults of 2 types
-	;   -Access Violaton	: 00_23_(00|01|02|03)_00
-	;			         x  r  w  r+w
-	;   -Unaligned Access	: 00_23_04_00
-	;
-	bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f
-
-	;========= (6a) Access Violation Processing ========
-	bl  do_page_fault
-	b   ret_from_exception
-
-	;========== (6b) Non aligned access ============
-4:
-
-	SAVE_CALLEE_SAVED_USER
-	mov r2, sp              ; callee_regs
-
-	bl  do_misaligned_access
-
-	; TBD: optimize - do this only if a callee reg was involved
-	; either a dst of emulated LD/ST or src with address-writeback
-	RESTORE_CALLEE_SAVED_USER
-
-	b   ret_from_exception
-
-END(EV_TLBProtV)
-
-; Wrapper for Linux page fault handler called from EV_TLBMiss*
-; Very similar to ProtV handler case (6a) above, but avoids the extra checks
-; for Misaligned access
-;
-ENTRY(call_do_page_fault)
-
-	EXCEPTION_PROLOGUE
-	lr  r0, [efa]	; Faulting Data address
-	mov   r1, sp
-	FAKE_RET_FROM_EXCPN
-
-	mov blink, ret_from_exception
-	b  do_page_fault
-
-END(call_do_page_fault)
-
-; ---------------------------------------------
 ; Privilege Violation Exception Handler
 ; ---------------------------------------------
 ENTRY(EV_PrivilegeV)
@@ -625,97 +337,7 @@ resume_kernel_mode:
 	; preempt_schedule_irq() always returns with IRQ disabled
 #endif
 
-	; fall through
-
-;############# Return from Intr/Excp/Trap (ARC Specifics) ##############
-;
-; Restore the saved sys context (common exit-path for EXCPN/IRQ/Trap)
-; IRQ shd definitely not happen between now and rtie
-; All 2 entry points to here already disable interrupts
-
-.Lrestore_regs:
-
-	TRACE_ASM_IRQ_ENABLE
-
-	lr	r10, [status32]
-
-	; Restore REG File. In case multiple Events outstanding,
-	; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None
-	; Note that we use realtime STATUS32 (not pt_regs->status32) to
-	; decide that.
-
-	; if Returning from Exception
-	bbit0  r10, STATUS_AE_BIT, not_exception
-	EXCEPTION_EPILOGUE
-	rtie
-
-	; Not Exception so maybe Interrupts (Level 1 or 2)
-
-not_exception:
-
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-
-	; Level 2 interrupt return Path - from hardware standpoint
-	bbit0  r10, STATUS_A2_BIT, not_level2_interrupt
-
-	;------------------------------------------------------------------
-	; However the context returning might not have taken L2 intr itself
-	; e.g. Task'A' user-code -> L2 intr -> schedule -> 'B' user-code ret
-	; Special considerations needed for the context which took L2 intr
-
-	ld   r9, [sp, PT_event]        ; Ensure this is L2 intr context
-	brne r9, event_IRQ2, 149f
-
-	;------------------------------------------------------------------
-	; if L2 IRQ interrupted an L1 ISR,  we'd disabled preemption earlier
-	; so that sched doesn't move to new task, causing L1 to be delayed
-	; undeterministically. Now that we've achieved that, let's reset
-	; things to what they were, before returning from L2 context
-	;----------------------------------------------------------------
-
-	ld r9, [sp, PT_status32]       ; get statu32_l2 (saved in pt_regs)
-	bbit0 r9, STATUS_A1_BIT, 149f  ; L1 not active when L2 IRQ, so normal
-
-	; decrement thread_info->preempt_count (re-enable preemption)
-	GET_CURR_THR_INFO_FROM_SP   r10
-	ld      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-
-	; paranoid check, given A1 was active when A2 happened, preempt count
-	; must not be 0 because we would have incremented it.
-	; If this does happen we simply HALT as it means a BUG !!!
-	cmp     r9, 0
-	bnz     2f
-	flag 1
-
-2:
-	sub     r9, r9, 1
-	st      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-
-149:
-	;return from level 2
-	INTERRUPT_EPILOGUE 2
-debug_marker_l2:
-	rtie
-
-not_level2_interrupt:
-
-#endif
-
-	bbit0  r10, STATUS_A1_BIT, not_level1_interrupt
-
-	;return from level 1
-	INTERRUPT_EPILOGUE 1
-debug_marker_l1:
-	rtie
-
-not_level1_interrupt:
-
-	;this case is for syscalls or Exceptions (with fake rtie)
-
-	EXCEPTION_EPILOGUE
-debug_marker_syscall:
-	rtie
-
+	b	.Lrestore_regs
 END(ret_from_exception)
 
 ENTRY(ret_from_fork)
@@ -762,4 +384,7 @@ END(sys_clone_wrapper)
 ; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)
 ; would not work after a clean build due to kernel build system dependencies.
 .section .debug_frame, "wa",@progbits
+
+; Reset to .text as this file is included in entry-<isa>.S
+.section .text, "ax",@progbits
 #endif
-- 
1.9.1

[PATCH 14/19] ARC: entry.S: move some code around for cache locality in return path

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry-compact.S |  2 +
 arch/arc/kernel/entry.S         | 98 +++++++++++++++++++++--------------------
 2 files changed, 52 insertions(+), 48 deletions(-)

diff --git a/arch/arc/kernel/entry-compact.S b/arch/arc/kernel/entry-compact.S
index bf611ec9a017..abc62cd10a8c 100644
--- a/arch/arc/kernel/entry-compact.S
+++ b/arch/arc/kernel/entry-compact.S
@@ -391,3 +391,5 @@ not_level1_interrupt:
 	EXCEPTION_EPILOGUE
 debug_marker_syscall:
 	rtie
+
+END(ret_from_exception)
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 75cdc56351d9..603266eb75e1 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -24,6 +24,55 @@
  *------------------------------------------------------------------
  */
 
+;################### Special Sys Call Wrappers ##########################
+
+ENTRY(sys_clone_wrapper)
+	SAVE_CALLEE_SAVED_USER
+	bl  @sys_clone
+	DISCARD_CALLEE_SAVED_USER
+
+	GET_CURR_THR_INFO_FLAGS   r10
+	btst r10, TIF_SYSCALL_TRACE
+	bnz  tracesys_exit
+
+	b ret_from_system_call
+END(sys_clone_wrapper)
+
+ENTRY(ret_from_fork)
+	; when the forked child comes here from the __switch_to function
+	; r0 has the last task pointer.
+	; put last task in scheduler queue
+	bl   @schedule_tail
+
+	ld   r9, [sp, PT_status32]
+	brne r9, 0, 1f
+
+	jl.d [r14]		; kernel thread entry point
+	mov  r0, r13		; (see PF_KTHREAD block in copy_thread)
+
+1:
+	; Return to user space
+	; 1. Any forked task (Reach here via BRne above)
+	; 2. First ever init task (Reach here via return from JL above)
+	;    This is the historic "kernel_execve" use-case, to return to init
+	;    user mode, in a round about way since that is always done from
+	;    a kernel thread which is executed via JL above but always returns
+	;    out whenever kernel_execve (now inline do_fork()) is involved
+	b    ret_from_exception
+END(ret_from_fork)
+
+#ifdef CONFIG_ARC_DW2_UNWIND
+; Workaround for bug 94179 (STAR ):
+; Despite -fasynchronous-unwind-tables, linker is not making dwarf2 unwinder
+; section (.debug_frame) as loadable. So we force it here.
+; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)
+; would not work after a clean build due to kernel build system dependencies.
+.section .debug_frame, "wa",@progbits
+
+; Reset to .text as this file is included in entry-<isa>.S
+.section .text, "ax",@progbits
+#endif
+
 ;################### Non TLB Exception Handling #############################
 
 ; ---------------------------------------------
@@ -338,53 +387,6 @@ resume_kernel_mode:
 #endif
 
 	b	.Lrestore_regs
-END(ret_from_exception)
-
-ENTRY(ret_from_fork)
-	; when the forked child comes here from the __switch_to function
-	; r0 has the last task pointer.
-	; put last task in scheduler queue
-	bl   @schedule_tail
-
-	ld   r9, [sp, PT_status32]
-	brne r9, 0, 1f
-
-	jl.d [r14]		; kernel thread entry point
-	mov  r0, r13		; (see PF_KTHREAD block in copy_thread)
-
-1:
-	; Return to user space
-	; 1. Any forked task (Reach here via BRne above)
-	; 2. First ever init task (Reach here via return from JL above)
-	;    This is the historic "kernel_execve" use-case, to return to init
-	;    user mode, in a round about way since that is always done from
-	;    a kernel thread which is executed via JL above but always returns
-	;    out whenever kernel_execve (now inline do_fork()) is involved
-	b    ret_from_exception
-END(ret_from_fork)
 
-;################### Special Sys Call Wrappers ##########################
-
-ENTRY(sys_clone_wrapper)
-	SAVE_CALLEE_SAVED_USER
-	bl  @sys_clone
-	DISCARD_CALLEE_SAVED_USER
-
-	GET_CURR_THR_INFO_FLAGS   r10
-	btst r10, TIF_SYSCALL_TRACE
-	bnz  tracesys_exit
-
-	b ret_from_system_call
-END(sys_clone_wrapper)
-
-#ifdef CONFIG_ARC_DW2_UNWIND
-; Workaround for bug 94179 (STAR ):
-; Despite -fasynchronous-unwind-tables, linker is not making dwarf2 unwinder
-; section (.debug_frame) as loadable. So we force it here.
-; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)
-; would not work after a clean build due to kernel build system dependencies.
-.section .debug_frame, "wa",@progbits
+##### DONT ADD CODE HERE - .Lrestore_regs actually follows in entry-<isa>.S
 
-; Reset to .text as this file is included in entry-<isa>.S
-.section .text, "ax",@progbits
-#endif
-- 
1.9.1

[PATCH 15/19] ARC: entry.S: micro-optimize Trap handler

[Vineet Gupta]

Elide the need to re-read ECR in Trap handler by ensuring that
EXCEPTION_PROLOGUE does that at the very end just before returning
to Trap handler

ARCv2 EXCEPTION_PROLOGUE already did that, so same for ARcompact and the
common trap handler adjusted to use cached ECR

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry-compact.h | 5 +++--
 arch/arc/kernel/entry.S              | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
index 6c0a81b598d2..8b65eb36655a 100644
--- a/arch/arc/include/asm/entry-compact.h
+++ b/arch/arc/include/asm/entry-compact.h
@@ -181,8 +181,6 @@
 	/* ARC700 doesn't provide auto-stack switching */
 	SWITCH_TO_KERNEL_STK
 
-	lr	r9, [ecr]
-	st      r9, [sp, 8]    /* ECR */
 	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
 
 	/* Restore r9 used to code the early prologue */
@@ -198,6 +196,9 @@
 	PUSHAX	lp_end
 	PUSHAX	lp_start
 	PUSHAX	erbta
+
+	lr	r9, [ecr]
+	st      r9, [sp, PT_event]    /* EV_Trap expects r9 to have ECR */
 .endm
 
 /*--------------------------------------------------------------
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 603266eb75e1..f7a82fd4d601 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -258,8 +258,8 @@ ENTRY(EV_Trap)
 	EXCEPTION_PROLOGUE
 
 	;============ TRAP 1   :breakpoints
-	lr     r10, [ecr]
-	bmsk.f 0, r10, 7
+	; Check ECR for trap with arg (PROLOGUE ensures r9 has ECR)
+	bmsk.f 0, r9, 7
 	bnz    trap_with_param
 
 	;============ TRAP  (no param): syscall top level
-- 
1.9.1

[PATCH 16/19] ARC: entry.S: use single EXCEPTION_PROLOGUE

[Vineet Gupta]

Returning from pure kernel mode and exception mode use the same code
anyways. Remove one the duplicate blocks

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/entry-compact.S | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/arc/kernel/entry-compact.S b/arch/arc/kernel/entry-compact.S
index abc62cd10a8c..15d457b4403a 100644
--- a/arch/arc/kernel/entry-compact.S
+++ b/arch/arc/kernel/entry-compact.S
@@ -321,14 +321,11 @@ END(call_do_page_fault)
 	; decide that.
 
 	; if Returning from Exception
-	bbit0  r10, STATUS_AE_BIT, not_exception
-	EXCEPTION_EPILOGUE
-	rtie
+	btst   r10, STATUS_AE_BIT
+	bnz    .Lexcep_ret
 
 	; Not Exception so maybe Interrupts (Level 1 or 2)
 
-not_exception:
-
 #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
 
 	; Level 2 interrupt return Path - from hardware standpoint
@@ -377,16 +374,17 @@ not_level2_interrupt:
 
 #endif
 
-	bbit0  r10, STATUS_A1_BIT, not_level1_interrupt
+	bbit0  r10, STATUS_A1_BIT, .Lpure_k_mode_ret
 
 	;return from level 1
 	INTERRUPT_EPILOGUE 1
 debug_marker_l1:
 	rtie
 
-not_level1_interrupt:
+.Lexcep_ret:
+.Lpure_k_mode_ret:
 
-	;this case is for syscalls or Exceptions (with fake rtie)
+	;this case is for syscalls or Exceptions or pure kernel mode
 
 	EXCEPTION_EPILOGUE
 debug_marker_syscall:
-- 
1.9.1

[PATCH 17/19] ARC: entry.S: [arcompact] simplify SWITCH_TO_KERNEL_STK

[Vineet Gupta]

Previously this macro was overloaded with stack switching, saving SP at right
slot in pt_regs, saving/setup of r25 and setting SP baseline to where
pt_regs->sp is saved (vs. bottom of pt_regs)

Now it only does SP switch, and leaves SP pointing to bottom of pt_regs.

r25 saving is no longer done here to allow for future reordering of
regfile in pt_regs w/o touching this macro

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry-compact.h | 71 ++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 36 deletions(-)

diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
index 8b65eb36655a..8d0dd4d1001c 100644
--- a/arch/arc/include/asm/entry-compact.h
+++ b/arch/arc/include/asm/entry-compact.h
@@ -39,8 +39,8 @@
  * Switch to Kernel Mode stack if SP points to User Mode stack
  *
  * Entry   : r9 contains pre-IRQ/exception/trap status32
- * Exit    : SP is set to kernel mode stack pointer
- *           If CURR_IN_REG, r25 set to "current" task pointer
+ * Exit    : SP set to K mode stack
+ *           SP at the time of entry (K/U) saved @ pt_regs->sp
  * Clobbers: r9
  *-------------------------------------------------------------*/
 
@@ -80,12 +80,11 @@
 
 #endif
 
-	/* Save Pre Intr/Exception KERNEL MODE SP on kernel stack
-	 * safe-keeping not really needed, but it keeps the epilogue code
-	 * (SP restore) simpler/uniform.
-	 */
+    /*------Intr/Ecxp happened in kernel mode, SP already setup ------ */
+	/* save it nevertheless @ pt_regs->sp for uniformity */
+
 	b.d	66f
-	mov	r9, sp
+	st	sp, [sp, PT_sp - SZ_PT_REGS]
 
 88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
 
@@ -94,30 +93,12 @@
 	/* With current tsk in r9, get it's kernel mode stack base */
 	GET_TSK_STACK_BASE  r9, r9
 
-66:
-#ifdef CONFIG_ARC_CURR_IN_REG
-	/*
-	 * Treat r25 as scratch reg, save it on stack first
-	 * Load it with current task pointer
-	 */
-	st	r25, [r9, -4]
-	GET_CURR_TASK_ON_CPU   r25
-#endif
-
-	/* Save Pre Intr/Exception User SP on kernel stack */
-	st.a    sp, [r9, -16]	; Make room for orig_r0, ECR, user_r25
-
-	/* CAUTION:
-	 * SP should be set at the very end when we are done with everything
-	 * In case of 2 levels of interrupt we depend on value of SP to assume
-	 * that everything else is done (loading r25 etc)
-	 */
-
-	/* set SP to point to kernel mode stack */
-	mov sp, r9
-
-	/* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
+	/* save U mode SP @ pt_regs->sp */
+	st	sp, [r9, PT_sp - SZ_PT_REGS]
 
+	/* final SP switch */
+	mov	sp, r9
+66:
 .endm
 
 /*------------------------------------------------------------
@@ -181,11 +162,21 @@
 	/* ARC700 doesn't provide auto-stack switching */
 	SWITCH_TO_KERNEL_STK
 
-	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
+#ifdef CONFIG_ARC_CURR_IN_REG
+	/* Treat r25 as scratch reg (save it on stack) and load with "current" */
+	PUSH    r25
+	GET_CURR_TASK_ON_CPU   r25
+#else
+	sub     sp, sp, 4
+#endif
+
+	st.a	r0, [sp, -8]    /* orig_r0 needed for syscall (skip ECR slot) */
+	sub	sp, sp, 4	/* skip pt_regs->sp, already saved above */
 
 	/* Restore r9 used to code the early prologue */
 	PROLOG_RESTORE_REG  r9, @ex_saved_reg1
 
+	/* now we are ready to save the regfile */
 	SAVE_R0_TO_R12
 	PUSH	gp
 	PUSH	fp
@@ -245,12 +236,20 @@
 
 	SWITCH_TO_KERNEL_STK
 
-	/* restore original r9 */
-	PROLOG_RESTORE_REG  r9, @int\LVL\()_saved_reg
+#ifdef CONFIG_ARC_CURR_IN_REG
+	/* Treat r25 as scratch reg (save it on stack) and load with "current" */
+	PUSH    r25
+	GET_CURR_TASK_ON_CPU   r25
+#else
+	sub     sp, sp, 4
+#endif
 
-	/* now we are ready to save the remaining context */
-	st	0x003\LVL\()abcd, [sp, 8]    /* Dummy ECR */
-	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
+	PUSH	0x003\LVL\()abcd	/* Dummy ECR */
+	sub	sp, sp, 8		/* skip orig_r0 (not needed)
+					   skip pt_regs->sp, already saved above */
+
+	/* Restore r9 used to code the early prologue */
+	PROLOG_RESTORE_REG  r9, @int\LVL\()_saved_reg
 
 	SAVE_R0_TO_R12
 	PUSH	gp
-- 
1.9.1

[PATCH 18/19] ARC: Make way for pt_regs != user_regs_struct

[Vineet Gupta]

These have been register compatible so far. However ARCv2 mandates
different pt_regs layout (due to h/w auto save). To keep pt_regs same
for both, we start by removing the assumption - used mainly for block
copies between the 2 structs in signal handling and ptrace

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/ptrace.c | 90 ++++++++++++++++++++++++++++++++++++++++++++----
 arch/arc/kernel/signal.c | 55 +++++++++++++++++++++++++++--
 2 files changed, 136 insertions(+), 9 deletions(-)

diff --git a/arch/arc/kernel/ptrace.c b/arch/arc/kernel/ptrace.c
index 13b3ffb27a38..4dd9e3a8c2da 100644
--- a/arch/arc/kernel/ptrace.c
+++ b/arch/arc/kernel/ptrace.c
@@ -47,10 +47,47 @@ static int genregs_get(struct task_struct *target,
 			offsetof(struct user_regs_struct, LOC) + 4);
 
 	REG_O_ZERO(pad);
-	REG_O_CHUNK(scratch, callee, ptregs);
+	REG_O_ONE(scratch.bta, &ptregs->bta);
+	REG_O_ONE(scratch.lp_start, &ptregs->lp_start);
+	REG_O_ONE(scratch.lp_end, &ptregs->lp_end);
+	REG_O_ONE(scratch.lp_count, &ptregs->lp_count);
+	REG_O_ONE(scratch.status32, &ptregs->status32);
+	REG_O_ONE(scratch.ret, &ptregs->ret);
+	REG_O_ONE(scratch.blink, &ptregs->blink);
+	REG_O_ONE(scratch.fp, &ptregs->fp);
+	REG_O_ONE(scratch.gp, &ptregs->r26);
+	REG_O_ONE(scratch.r12, &ptregs->r12);
+	REG_O_ONE(scratch.r11, &ptregs->r11);
+	REG_O_ONE(scratch.r10, &ptregs->r10);
+	REG_O_ONE(scratch.r9, &ptregs->r9);
+	REG_O_ONE(scratch.r8, &ptregs->r8);
+	REG_O_ONE(scratch.r7, &ptregs->r7);
+	REG_O_ONE(scratch.r6, &ptregs->r6);
+	REG_O_ONE(scratch.r5, &ptregs->r5);
+	REG_O_ONE(scratch.r4, &ptregs->r4);
+	REG_O_ONE(scratch.r3, &ptregs->r3);
+	REG_O_ONE(scratch.r2, &ptregs->r2);
+	REG_O_ONE(scratch.r1, &ptregs->r1);
+	REG_O_ONE(scratch.r0, &ptregs->r0);
+	REG_O_ONE(scratch.sp, &ptregs->sp);
+
 	REG_O_ZERO(pad2);
-	REG_O_CHUNK(callee, efa, cregs);
-	REG_O_CHUNK(efa, stop_pc, &target->thread.fault_address);
+
+	REG_O_ONE(callee.r25, &cregs->r25);
+	REG_O_ONE(callee.r24, &cregs->r24);
+	REG_O_ONE(callee.r23, &cregs->r23);
+	REG_O_ONE(callee.r22, &cregs->r22);
+	REG_O_ONE(callee.r21, &cregs->r21);
+	REG_O_ONE(callee.r20, &cregs->r20);
+	REG_O_ONE(callee.r19, &cregs->r19);
+	REG_O_ONE(callee.r18, &cregs->r18);
+	REG_O_ONE(callee.r17, &cregs->r17);
+	REG_O_ONE(callee.r16, &cregs->r16);
+	REG_O_ONE(callee.r15, &cregs->r15);
+	REG_O_ONE(callee.r14, &cregs->r14);
+	REG_O_ONE(callee.r13, &cregs->r13);
+
+	REG_O_ONE(efa, &target->thread.fault_address);
 
 	if (!ret) {
 		if (in_brkpt_trap(ptregs)) {
@@ -97,12 +134,51 @@ static int genregs_set(struct task_struct *target,
 			offsetof(struct user_regs_struct, LOC) + 4);
 
 	REG_IGNORE_ONE(pad);
-	/* TBD: disallow updates to STATUS32 etc*/
-	REG_IN_CHUNK(scratch, pad2, ptregs);	/* pt_regs[bta..sp] */
+
+	REG_IN_ONE(scratch.bta, &ptregs->bta);
+	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
+	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
+	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
+
+	REG_IGNORE_ONE(scratch.status32);
+
+	REG_IN_ONE(scratch.ret, &ptregs->ret);
+	REG_IN_ONE(scratch.blink, &ptregs->blink);
+	REG_IN_ONE(scratch.fp, &ptregs->fp);
+	REG_IN_ONE(scratch.gp, &ptregs->r26);
+	REG_IN_ONE(scratch.r12, &ptregs->r12);
+	REG_IN_ONE(scratch.r11, &ptregs->r11);
+	REG_IN_ONE(scratch.r10, &ptregs->r10);
+	REG_IN_ONE(scratch.r9, &ptregs->r9);
+	REG_IN_ONE(scratch.r8, &ptregs->r8);
+	REG_IN_ONE(scratch.r7, &ptregs->r7);
+	REG_IN_ONE(scratch.r6, &ptregs->r6);
+	REG_IN_ONE(scratch.r5, &ptregs->r5);
+	REG_IN_ONE(scratch.r4, &ptregs->r4);
+	REG_IN_ONE(scratch.r3, &ptregs->r3);
+	REG_IN_ONE(scratch.r2, &ptregs->r2);
+	REG_IN_ONE(scratch.r1, &ptregs->r1);
+	REG_IN_ONE(scratch.r0, &ptregs->r0);
+	REG_IN_ONE(scratch.sp, &ptregs->sp);
+
 	REG_IGNORE_ONE(pad2);
-	REG_IN_CHUNK(callee, efa, cregs);	/* callee_regs[r25..r13] */
+
+	REG_IN_ONE(callee.r25, &cregs->r25);
+	REG_IN_ONE(callee.r24, &cregs->r24);
+	REG_IN_ONE(callee.r23, &cregs->r23);
+	REG_IN_ONE(callee.r22, &cregs->r22);
+	REG_IN_ONE(callee.r21, &cregs->r21);
+	REG_IN_ONE(callee.r20, &cregs->r20);
+	REG_IN_ONE(callee.r19, &cregs->r19);
+	REG_IN_ONE(callee.r18, &cregs->r18);
+	REG_IN_ONE(callee.r17, &cregs->r17);
+	REG_IN_ONE(callee.r16, &cregs->r16);
+	REG_IN_ONE(callee.r15, &cregs->r15);
+	REG_IN_ONE(callee.r14, &cregs->r14);
+	REG_IN_ONE(callee.r13, &cregs->r13);
+
 	REG_IGNORE_ONE(efa);			/* efa update invalid */
-	REG_IGNORE_ONE(stop_pc);			/* PC updated via @ret */
+	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
 
 	return ret;
 }
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c
index 2251fb4bbfd7..b99dbbb63239 100644
--- a/arch/arc/kernel/signal.c
+++ b/arch/arc/kernel/signal.c
@@ -67,7 +67,33 @@ stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
 	       sigset_t *set)
 {
 	int err;
-	err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), regs,
+	struct user_regs_struct uregs;
+
+	uregs.scratch.bta	= regs->bta;
+	uregs.scratch.lp_start	= regs->lp_start;
+	uregs.scratch.lp_end	= regs->lp_end;
+	uregs.scratch.lp_count	= regs->lp_count;
+	uregs.scratch.status32	= regs->status32;
+	uregs.scratch.ret	= regs->ret;
+	uregs.scratch.blink	= regs->blink;
+	uregs.scratch.fp	= regs->fp;
+	uregs.scratch.gp	= regs->r26;
+	uregs.scratch.r12	= regs->r12;
+	uregs.scratch.r11	= regs->r11;
+	uregs.scratch.r10	= regs->r10;
+	uregs.scratch.r9	= regs->r9;
+	uregs.scratch.r8	= regs->r8;
+	uregs.scratch.r7	= regs->r7;
+	uregs.scratch.r6	= regs->r6;
+	uregs.scratch.r5	= regs->r5;
+	uregs.scratch.r4	= regs->r4;
+	uregs.scratch.r3	= regs->r3;
+	uregs.scratch.r2	= regs->r2;
+	uregs.scratch.r1	= regs->r1;
+	uregs.scratch.r0	= regs->r0;
+	uregs.scratch.sp	= regs->sp;
+
+	err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), &uregs.scratch,
 			     sizeof(sf->uc.uc_mcontext.regs.scratch));
 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
 
@@ -78,14 +104,39 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
 {
 	sigset_t set;
 	int err;
+	struct user_regs_struct uregs;
 
 	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
 	if (!err)
 		set_current_blocked(&set);
 
-	err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs.scratch),
+	err |= __copy_from_user(&uregs.scratch, &(sf->uc.uc_mcontext.regs.scratch),
 				sizeof(sf->uc.uc_mcontext.regs.scratch));
 
+	regs->bta	= uregs.scratch.bta;
+	regs->lp_start	= uregs.scratch.lp_start;
+	regs->lp_end	= uregs.scratch.lp_end;
+	regs->lp_count	= uregs.scratch.lp_count;
+	regs->status32	= uregs.scratch.status32;
+	regs->ret	= uregs.scratch.ret;
+	regs->blink	= uregs.scratch.blink;
+	regs->fp	= uregs.scratch.fp;
+	regs->r26	= uregs.scratch.gp;
+	regs->r12	= uregs.scratch.r12;
+	regs->r11	= uregs.scratch.r11;
+	regs->r10	= uregs.scratch.r10;
+	regs->r9	= uregs.scratch.r9;
+	regs->r8	= uregs.scratch.r8;
+	regs->r7	= uregs.scratch.r7;
+	regs->r6	= uregs.scratch.r6;
+	regs->r5	= uregs.scratch.r5;
+	regs->r4	= uregs.scratch.r4;
+	regs->r3	= uregs.scratch.r3;
+	regs->r2	= uregs.scratch.r2;
+	regs->r1	= uregs.scratch.r1;
+	regs->r0	= uregs.scratch.r0;
+	regs->sp	= uregs.scratch.sp;
+
 	return err;
 }
 
-- 
1.9.1

[PATCH 19/19] ARC: intc: split into ARCompact ISA specific, common bits

[Vineet Gupta]

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/entry-compact.h    |   1 +
 arch/arc/include/asm/irqflags-compact.h | 181 +++++++++++++++++++++++++
 arch/arc/include/asm/irqflags.h         | 168 +----------------------
 arch/arc/kernel/Makefile                |   2 +-
 arch/arc/kernel/intc-compact.c          | 230 ++++++++++++++++++++++++++++++++
 arch/arc/kernel/irq.c                   | 210 -----------------------------
 arch/arc/kernel/process.c               |   3 +-
 7 files changed, 416 insertions(+), 379 deletions(-)
 create mode 100644 arch/arc/include/asm/irqflags-compact.h
 create mode 100644 arch/arc/kernel/intc-compact.c

diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
index 8d0dd4d1001c..a54081cf0c86 100644
--- a/arch/arc/include/asm/entry-compact.h
+++ b/arch/arc/include/asm/entry-compact.h
@@ -33,6 +33,7 @@
 #define __ASM_ARC_ENTRY_COMPACT_H
 
 #include <asm/asm-offsets.h>
+#include <asm/irqflags-compact.h>
 #include <asm/thread_info.h>	/* For THREAD_SIZE */
 
 /*--------------------------------------------------------------
diff --git a/arch/arc/include/asm/irqflags-compact.h b/arch/arc/include/asm/irqflags-compact.h
new file mode 100644
index 000000000000..bdb854840f10
--- /dev/null
+++ b/arch/arc/include/asm/irqflags-compact.h
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_IRQFLAGS_ARCOMPACT_H
+#define __ASM_IRQFLAGS_ARCOMPACT_H
+
+/* vineetg: March 2010 : local_irq_save( ) optimisation
+ *  -Remove explicit mov of current status32 into reg, that is not needed
+ *  -Use BIC  insn instead of INVERTED + AND
+ *  -Conditionally disable interrupts (if they are not enabled, don't disable)
+*/
+
+#include <asm/arcregs.h>
+
+/* status32 Reg bits related to Interrupt Handling */
+#define STATUS_E1_BIT		1	/* Int 1 enable */
+#define STATUS_E2_BIT		2	/* Int 2 enable */
+#define STATUS_A1_BIT		3	/* Int 1 active */
+#define STATUS_A2_BIT		4	/* Int 2 active */
+
+#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)
+#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)
+#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)
+#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)
+#define STATUS_IE_MASK		(STATUS_E1_MASK | STATUS_E2_MASK)
+
+/* Other Interrupt Handling related Aux regs */
+#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */
+#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */
+#define AUX_IRQ_LV12		0x43	/* interrupt level register */
+
+#define AUX_IENABLE		0x40c
+#define AUX_ITRIGGER		0x40d
+#define AUX_IPULSE		0x415
+
+#ifndef __ASSEMBLY__
+
+/******************************************************************
+ * IRQ Control Macros
+ *
+ * All of them have "memory" clobber (compiler barrier) which is needed to
+ * ensure that LD/ST requiring irq safetly (R-M-W when LLSC is not available)
+ * are redone after IRQs are re-enabled (and gcc doesn't reuse stale register)
+ *
+ * Noted at the time of Abilis Timer List corruption
+ * 	Orig Bug + Rejected solution	: https://lkml.org/lkml/2013/3/29/67
+ * 	Reasoning			: https://lkml.org/lkml/2013/4/8/15
+ *
+ ******************************************************************/
+
+/*
+ * Save IRQ state and disable IRQs
+ */
+static inline long arch_local_irq_save(void)
+{
+	unsigned long temp, flags;
+
+	__asm__ __volatile__(
+	"	lr  %1, [status32]	\n"
+	"	bic %0, %1, %2		\n"
+	"	and.f 0, %1, %2	\n"
+	"	flag.nz %0		\n"
+	: "=r"(temp), "=r"(flags)
+	: "n"((STATUS_E1_MASK | STATUS_E2_MASK))
+	: "memory", "cc");
+
+	return flags;
+}
+
+/*
+ * restore saved IRQ state
+ */
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+
+	__asm__ __volatile__(
+	"	flag %0			\n"
+	:
+	: "r"(flags)
+	: "memory");
+}
+
+/*
+ * Unconditionally Enable IRQs
+ */
+extern void arch_local_irq_enable(void);
+
+/*
+ * Unconditionally Disable IRQs
+ */
+static inline void arch_local_irq_disable(void)
+{
+	unsigned long temp;
+
+	__asm__ __volatile__(
+	"	lr  %0, [status32]	\n"
+	"	and %0, %0, %1		\n"
+	"	flag %0			\n"
+	: "=&r"(temp)
+	: "n"(~(STATUS_E1_MASK | STATUS_E2_MASK))
+	: "memory");
+}
+
+/*
+ * save IRQ state
+ */
+static inline long arch_local_save_flags(void)
+{
+	unsigned long temp;
+
+	__asm__ __volatile__(
+	"	lr  %0, [status32]	\n"
+	: "=&r"(temp)
+	:
+	: "memory");
+
+	return temp;
+}
+
+/*
+ * Query IRQ state
+ */
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+	return !(flags & (STATUS_E1_MASK
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+			| STATUS_E2_MASK
+#endif
+		));
+}
+
+static inline int arch_irqs_disabled(void)
+{
+	return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+#else
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+.macro TRACE_ASM_IRQ_DISABLE
+	bl	trace_hardirqs_off
+.endm
+
+.macro TRACE_ASM_IRQ_ENABLE
+	bl	trace_hardirqs_on
+.endm
+
+#else
+
+.macro TRACE_ASM_IRQ_DISABLE
+.endm
+
+.macro TRACE_ASM_IRQ_ENABLE
+.endm
+
+#endif
+
+.macro IRQ_DISABLE  scratch
+	lr	\scratch, [status32]
+	bic	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
+	flag	\scratch
+	TRACE_ASM_IRQ_DISABLE
+.endm
+
+.macro IRQ_ENABLE  scratch
+	lr	\scratch, [status32]
+	or	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
+	flag	\scratch
+	TRACE_ASM_IRQ_ENABLE
+.endm
+
+#endif	/* __ASSEMBLY__ */
+
+#endif
diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h
index 27ecc6975a58..333972600680 100644
--- a/arch/arc/include/asm/irqflags.h
+++ b/arch/arc/include/asm/irqflags.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  *
  * This program is free software; you can redistribute it and/or modify
@@ -9,171 +10,6 @@
 #ifndef __ASM_ARC_IRQFLAGS_H
 #define __ASM_ARC_IRQFLAGS_H
 
-/* vineetg: March 2010 : local_irq_save( ) optimisation
- *  -Remove explicit mov of current status32 into reg, that is not needed
- *  -Use BIC  insn instead of INVERTED + AND
- *  -Conditionally disable interrupts (if they are not enabled, don't disable)
-*/
-
-#include <asm/arcregs.h>
-
-/* status32 Reg bits related to Interrupt Handling */
-#define STATUS_E1_BIT		1	/* Int 1 enable */
-#define STATUS_E2_BIT		2	/* Int 2 enable */
-#define STATUS_A1_BIT		3	/* Int 1 active */
-#define STATUS_A2_BIT		4	/* Int 2 active */
-
-#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)
-#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)
-#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)
-#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)
-
-/* Other Interrupt Handling related Aux regs */
-#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */
-#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */
-#define AUX_IRQ_LV12		0x43	/* interrupt level register */
-
-#define AUX_IENABLE		0x40c
-#define AUX_ITRIGGER		0x40d
-#define AUX_IPULSE		0x415
-
-#ifndef __ASSEMBLY__
-
-/******************************************************************
- * IRQ Control Macros
- *
- * All of them have "memory" clobber (compiler barrier) which is needed to
- * ensure that LD/ST requiring irq safetly (R-M-W when LLSC is not available)
- * are redone after IRQs are re-enabled (and gcc doesn't reuse stale register)
- *
- * Noted at the time of Abilis Timer List corruption
- * 	Orig Bug + Rejected solution	: https://lkml.org/lkml/2013/3/29/67
- * 	Reasoning			: https://lkml.org/lkml/2013/4/8/15
- *
- ******************************************************************/
-
-/*
- * Save IRQ state and disable IRQs
- */
-static inline long arch_local_irq_save(void)
-{
-	unsigned long temp, flags;
-
-	__asm__ __volatile__(
-	"	lr  %1, [status32]	\n"
-	"	bic %0, %1, %2		\n"
-	"	and.f 0, %1, %2	\n"
-	"	flag.nz %0		\n"
-	: "=r"(temp), "=r"(flags)
-	: "n"((STATUS_E1_MASK | STATUS_E2_MASK))
-	: "memory", "cc");
-
-	return flags;
-}
-
-/*
- * restore saved IRQ state
- */
-static inline void arch_local_irq_restore(unsigned long flags)
-{
-
-	__asm__ __volatile__(
-	"	flag %0			\n"
-	:
-	: "r"(flags)
-	: "memory");
-}
-
-/*
- * Unconditionally Enable IRQs
- */
-extern void arch_local_irq_enable(void);
-
-/*
- * Unconditionally Disable IRQs
- */
-static inline void arch_local_irq_disable(void)
-{
-	unsigned long temp;
-
-	__asm__ __volatile__(
-	"	lr  %0, [status32]	\n"
-	"	and %0, %0, %1		\n"
-	"	flag %0			\n"
-	: "=&r"(temp)
-	: "n"(~(STATUS_E1_MASK | STATUS_E2_MASK))
-	: "memory");
-}
-
-/*
- * save IRQ state
- */
-static inline long arch_local_save_flags(void)
-{
-	unsigned long temp;
-
-	__asm__ __volatile__(
-	"	lr  %0, [status32]	\n"
-	: "=&r"(temp)
-	:
-	: "memory");
-
-	return temp;
-}
-
-/*
- * Query IRQ state
- */
-static inline int arch_irqs_disabled_flags(unsigned long flags)
-{
-	return !(flags & (STATUS_E1_MASK
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-			| STATUS_E2_MASK
-#endif
-		));
-}
-
-static inline int arch_irqs_disabled(void)
-{
-	return arch_irqs_disabled_flags(arch_local_save_flags());
-}
-
-#else
-
-#ifdef CONFIG_TRACE_IRQFLAGS
-
-.macro TRACE_ASM_IRQ_DISABLE
-	bl	trace_hardirqs_off
-.endm
-
-.macro TRACE_ASM_IRQ_ENABLE
-	bl	trace_hardirqs_on
-.endm
-
-#else
-
-.macro TRACE_ASM_IRQ_DISABLE
-.endm
-
-.macro TRACE_ASM_IRQ_ENABLE
-.endm
-
-#endif
-
-.macro IRQ_DISABLE  scratch
-	lr	\scratch, [status32]
-	bic	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
-	flag	\scratch
-	TRACE_ASM_IRQ_DISABLE
-.endm
-
-.macro IRQ_ENABLE  scratch
-	lr	\scratch, [status32]
-	or	\scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
-	flag	\scratch
-	TRACE_ASM_IRQ_ENABLE
-.endm
-
-#endif	/* __ASSEMBLY__ */
+#include <asm/irqflags-compact.h>
 
 #endif
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index 024a63e90b72..cc929c0e2133 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -10,7 +10,7 @@ CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o
 obj-y	+= signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o clk.o
-obj-y	+= entry-compact.o
+obj-y	+= entry-compact.o intc-compact.o
 
 obj-$(CONFIG_MODULES)			+= arcksyms.o module.o
 obj-$(CONFIG_SMP) 			+= smp.o
diff --git a/arch/arc/kernel/intc-compact.c b/arch/arc/kernel/intc-compact.c
new file mode 100644
index 000000000000..0ab1734d3b88
--- /dev/null
+++ b/arch/arc/kernel/intc-compact.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (C) 2011-12 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include "../../drivers/irqchip/irqchip.h"
+#include <asm/irq.h>
+
+/*
+ * Early Hardware specific Interrupt setup
+ * -Platform independent, needed for each CPU (not foldable into init_IRQ)
+ * -Called very early (start_kernel -> setup_arch -> setup_processor)
+ *
+ * what it does ?
+ * -Optionally, setup the High priority Interrupts as Level 2 IRQs
+ */
+void arc_init_IRQ(void)
+{
+	int level_mask = 0;
+
+       /* setup any high priority Interrupts (Level2 in ARCompact jargon) */
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ3_LV2) << 3;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ5_LV2) << 5;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ6_LV2) << 6;
+
+	/*
+	 * Write to register, even if no LV2 IRQs configured to reset it
+	 * in case bootloader had mucked with it
+	 */
+	write_aux_reg(AUX_IRQ_LEV, level_mask);
+
+	if (level_mask)
+		pr_info("Level-2 interrupts bitset %x\n", level_mask);
+}
+
+/*
+ * ARC700 core includes a simple on-chip intc supporting
+ * -per IRQ enable/disable
+ * -2 levels of interrupts (high/low)
+ * -all interrupts being level triggered
+ *
+ * To reduce platform code, we assume all IRQs directly hooked-up into intc.
+ * Platforms with external intc, hence cascaded IRQs, are free to over-ride
+ * below, per IRQ.
+ */
+
+static void arc_irq_mask(struct irq_data *data)
+{
+	unsigned int ienb;
+
+	ienb = read_aux_reg(AUX_IENABLE);
+	ienb &= ~(1 << data->irq);
+	write_aux_reg(AUX_IENABLE, ienb);
+}
+
+static void arc_irq_unmask(struct irq_data *data)
+{
+	unsigned int ienb;
+
+	ienb = read_aux_reg(AUX_IENABLE);
+	ienb |= (1 << data->irq);
+	write_aux_reg(AUX_IENABLE, ienb);
+}
+
+static struct irq_chip onchip_intc = {
+	.name           = "ARC In-core Intc",
+	.irq_mask	= arc_irq_mask,
+	.irq_unmask	= arc_irq_unmask,
+};
+
+static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq,
+			       irq_hw_number_t hw)
+{
+	/* For percpu devices, more efficient handler can be used */
+	//desc = irq_to_desc(irq);
+	//if (irqd_is_per_cpu(&desc->irq_data) &&
+
+	/*
+	 * XXX: the IPI IRQ needs to be handled like TIMER too. However ARC core
+	 *      code doesn't own it (like TIMER0). ISS IDU / ezchip define it
+	 *      in platform header which can't be included here as it goes
+	 *      against multi-platform image philisophy
+	 */
+	if (irq == TIMER0_IRQ)
+		irq_set_chip_and_handler(irq, &onchip_intc, handle_percpu_irq);
+	else
+		irq_set_chip_and_handler(irq, &onchip_intc, handle_level_irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops arc_intc_domain_ops = {
+	.xlate = irq_domain_xlate_onecell,
+	.map = arc_intc_domain_map,
+};
+
+static struct irq_domain *root_domain;
+
+static int __init
+init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
+{
+	if (parent)
+		panic("DeviceTree incore intc not a root irq controller\n");
+
+	root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,
+					    &arc_intc_domain_ops, NULL);
+
+	if (!root_domain)
+		panic("root irq domain not avail\n");
+
+	/* with this we don't need to export root_domain */
+	irq_set_default_host(root_domain);
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(arc_intc, "snps,arc700-intc", init_onchip_IRQ);
+
+/*
+ * arch_local_irq_enable - Enable interrupts.
+ *
+ * 1. Explicitly called to re-enable interrupts
+ * 2. Implicitly called from spin_unlock_irq, write_unlock_irq etc
+ *    which maybe in hard ISR itself
+ *
+ * Semantics of this function change depending on where it is called from:
+ *
+ * -If called from hard-ISR, it must not invert interrupt priorities
+ *  e.g. suppose TIMER is high priority (Level 2) IRQ
+ *    Time hard-ISR, timer_interrupt( ) calls spin_unlock_irq several times.
+ *    Here local_irq_enable( ) shd not re-enable lower priority interrupts
+ * -If called from soft-ISR, it must re-enable all interrupts
+ *    soft ISR are low prioity jobs which can be very slow, thus all IRQs
+ *    must be enabled while they run.
+ *    Now hardware context wise we may still be in L2 ISR (not done rtie)
+ *    still we must re-enable both L1 and L2 IRQs
+ *  Another twist is prev scenario with flow being
+ *     L1 ISR ==> interrupted by L2 ISR  ==> L2 soft ISR
+ *     here we must not re-enable Ll as prev Ll Interrupt's h/w context will get
+ *     over-written (this is deficiency in ARC700 Interrupt mechanism)
+ */
+
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS	/* Complex version for 2 IRQ levels */
+
+void arch_local_irq_enable(void)
+{
+
+	unsigned long flags;
+	flags = arch_local_save_flags();
+
+	/* Allow both L1 and L2 at the onset */
+	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);
+
+	/* Called from hard ISR (between irq_enter and irq_exit) */
+	if (in_irq()) {
+
+		/* If in L2 ISR, don't re-enable any further IRQs as this can
+		 * cause IRQ priorities to get upside down. e.g. it could allow
+		 * L1 be taken while in L2 hard ISR which is wrong not only in
+		 * theory, it can also cause the dreaded L1-L2-L1 scenario
+		 */
+		if (flags & STATUS_A2_MASK)
+			flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK);
+
+		/* Even if in L1 ISR, allowe Higher prio L2 IRQs */
+		else if (flags & STATUS_A1_MASK)
+			flags &= ~(STATUS_E1_MASK);
+	}
+
+	/* called from soft IRQ, ideally we want to re-enable all levels */
+
+	else if (in_softirq()) {
+
+		/* However if this is case of L1 interrupted by L2,
+		 * re-enabling both may cause whaco L1-L2-L1 scenario
+		 * because ARC700 allows level 1 to interrupt an active L2 ISR
+		 * Thus we disable both
+		 * However some code, executing in soft ISR wants some IRQs
+		 * to be enabled so we re-enable L2 only
+		 *
+		 * How do we determine L1 intr by L2
+		 *  -A2 is set (means in L2 ISR)
+		 *  -E1 is set in this ISR's pt_regs->status32 which is
+		 *      saved copy of status32_l2 when l2 ISR happened
+		 */
+		struct pt_regs *pt = get_irq_regs();
+		if ((flags & STATUS_A2_MASK) && pt &&
+		    (pt->status32 & STATUS_A1_MASK)) {
+			/*flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK); */
+			flags &= ~(STATUS_E1_MASK);
+		}
+	}
+
+	arch_local_irq_restore(flags);
+}
+
+#else /* ! CONFIG_ARC_COMPACT_IRQ_LEVELS */
+
+/*
+ * Simpler version for only 1 level of interrupt
+ * Here we only Worry about Level 1 Bits
+ */
+void arch_local_irq_enable(void)
+{
+	unsigned long flags;
+
+	/*
+	 * ARC IDE Drivers tries to re-enable interrupts from hard-isr
+	 * context which is simply wrong
+	 */
+	if (in_irq()) {
+		WARN_ONCE(1, "IRQ enabled from hard-isr");
+		return;
+	}
+
+	flags = arch_local_save_flags();
+	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);
+	arch_local_irq_restore(flags);
+}
+#endif
+EXPORT_SYMBOL(arch_local_irq_enable);
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index 620ec2fe32a9..2989a7bcf8a8 100644
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -8,116 +8,10 @@
  */
 
 #include <linux/interrupt.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/irqdomain.h>
 #include <linux/irqchip.h>
-#include "../../drivers/irqchip/irqchip.h"
-#include <asm/sections.h>
-#include <asm/irq.h>
 #include <asm/mach_desc.h>
 
 /*
- * Early Hardware specific Interrupt setup
- * -Platform independent, needed for each CPU (not foldable into init_IRQ)
- * -Called very early (start_kernel -> setup_arch -> setup_processor)
- *
- * what it does ?
- * -Optionally, setup the High priority Interrupts as Level 2 IRQs
- */
-void arc_init_IRQ(void)
-{
-	int level_mask = 0;
-
-       /* setup any high priority Interrupts (Level2 in ARCompact jargon) */
-	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ3_LV2) << 3;
-	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ5_LV2) << 5;
-	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ6_LV2) << 6;
-
-	/*
-	 * Write to register, even if no LV2 IRQs configured to reset it
-	 * in case bootloader had mucked with it
-	 */
-	write_aux_reg(AUX_IRQ_LEV, level_mask);
-
-	if (level_mask)
-		pr_info("Level-2 interrupts bitset %x\n", level_mask);
-}
-
-/*
- * ARC700 core includes a simple on-chip intc supporting
- * -per IRQ enable/disable
- * -2 levels of interrupts (high/low)
- * -all interrupts being level triggered
- *
- * To reduce platform code, we assume all IRQs directly hooked-up into intc.
- * Platforms with external intc, hence cascaded IRQs, are free to over-ride
- * below, per IRQ.
- */
-
-static void arc_irq_mask(struct irq_data *data)
-{
-	unsigned int ienb;
-
-	ienb = read_aux_reg(AUX_IENABLE);
-	ienb &= ~(1 << data->irq);
-	write_aux_reg(AUX_IENABLE, ienb);
-}
-
-static void arc_irq_unmask(struct irq_data *data)
-{
-	unsigned int ienb;
-
-	ienb = read_aux_reg(AUX_IENABLE);
-	ienb |= (1 << data->irq);
-	write_aux_reg(AUX_IENABLE, ienb);
-}
-
-static struct irq_chip onchip_intc = {
-	.name           = "ARC In-core Intc",
-	.irq_mask	= arc_irq_mask,
-	.irq_unmask	= arc_irq_unmask,
-};
-
-static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq,
-				irq_hw_number_t hw)
-{
-	if (irq == TIMER0_IRQ)
-		irq_set_chip_and_handler(irq, &onchip_intc, handle_percpu_irq);
-	else
-		irq_set_chip_and_handler(irq, &onchip_intc, handle_level_irq);
-
-	return 0;
-}
-
-static const struct irq_domain_ops arc_intc_domain_ops = {
-	.xlate = irq_domain_xlate_onecell,
-	.map = arc_intc_domain_map,
-};
-
-static struct irq_domain *root_domain;
-
-static int __init
-init_onchip_IRQ(struct device_node *intc, struct device_node *parent)
-{
-	if (parent)
-		panic("DeviceTree incore intc not a root irq controller\n");
-
-	root_domain = irq_domain_add_legacy(intc, NR_CPU_IRQS, 0, 0,
-					    &arc_intc_domain_ops, NULL);
-
-	if (!root_domain)
-		panic("root irq domain not avail\n");
-
-	/* with this we don't need to export root_domain */
-	irq_set_default_host(root_domain);
-
-	return 0;
-}
-
-IRQCHIP_DECLARE(arc_intc, "snps,arc700-intc", init_onchip_IRQ);
-
-/*
  * Late Interrupt system init called from start_kernel for Boot CPU only
  *
  * Since slab must already be initialized, platforms can start doing any
@@ -178,107 +72,3 @@ void arc_request_percpu_irq(int irq, int cpu,
 
 	enable_percpu_irq(irq, 0);
 }
-
-/*
- * arch_local_irq_enable - Enable interrupts.
- *
- * 1. Explicitly called to re-enable interrupts
- * 2. Implicitly called from spin_unlock_irq, write_unlock_irq etc
- *    which maybe in hard ISR itself
- *
- * Semantics of this function change depending on where it is called from:
- *
- * -If called from hard-ISR, it must not invert interrupt priorities
- *  e.g. suppose TIMER is high priority (Level 2) IRQ
- *    Time hard-ISR, timer_interrupt( ) calls spin_unlock_irq several times.
- *    Here local_irq_enable( ) shd not re-enable lower priority interrupts
- * -If called from soft-ISR, it must re-enable all interrupts
- *    soft ISR are low prioity jobs which can be very slow, thus all IRQs
- *    must be enabled while they run.
- *    Now hardware context wise we may still be in L2 ISR (not done rtie)
- *    still we must re-enable both L1 and L2 IRQs
- *  Another twist is prev scenario with flow being
- *     L1 ISR ==> interrupted by L2 ISR  ==> L2 soft ISR
- *     here we must not re-enable Ll as prev Ll Interrupt's h/w context will get
- *     over-written (this is deficiency in ARC700 Interrupt mechanism)
- */
-
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS	/* Complex version for 2 IRQ levels */
-
-void arch_local_irq_enable(void)
-{
-
-	unsigned long flags;
-	flags = arch_local_save_flags();
-
-	/* Allow both L1 and L2 at the onset */
-	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);
-
-	/* Called from hard ISR (between irq_enter and irq_exit) */
-	if (in_irq()) {
-
-		/* If in L2 ISR, don't re-enable any further IRQs as this can
-		 * cause IRQ priorities to get upside down. e.g. it could allow
-		 * L1 be taken while in L2 hard ISR which is wrong not only in
-		 * theory, it can also cause the dreaded L1-L2-L1 scenario
-		 */
-		if (flags & STATUS_A2_MASK)
-			flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK);
-
-		/* Even if in L1 ISR, allowe Higher prio L2 IRQs */
-		else if (flags & STATUS_A1_MASK)
-			flags &= ~(STATUS_E1_MASK);
-	}
-
-	/* called from soft IRQ, ideally we want to re-enable all levels */
-
-	else if (in_softirq()) {
-
-		/* However if this is case of L1 interrupted by L2,
-		 * re-enabling both may cause whaco L1-L2-L1 scenario
-		 * because ARC700 allows level 1 to interrupt an active L2 ISR
-		 * Thus we disable both
-		 * However some code, executing in soft ISR wants some IRQs
-		 * to be enabled so we re-enable L2 only
-		 *
-		 * How do we determine L1 intr by L2
-		 *  -A2 is set (means in L2 ISR)
-		 *  -E1 is set in this ISR's pt_regs->status32 which is
-		 *      saved copy of status32_l2 when l2 ISR happened
-		 */
-		struct pt_regs *pt = get_irq_regs();
-		if ((flags & STATUS_A2_MASK) && pt &&
-		    (pt->status32 & STATUS_A1_MASK)) {
-			/*flags &= ~(STATUS_E1_MASK | STATUS_E2_MASK); */
-			flags &= ~(STATUS_E1_MASK);
-		}
-	}
-
-	arch_local_irq_restore(flags);
-}
-
-#else /* ! CONFIG_ARC_COMPACT_IRQ_LEVELS */
-
-/*
- * Simpler version for only 1 level of interrupt
- * Here we only Worry about Level 1 Bits
- */
-void arch_local_irq_enable(void)
-{
-	unsigned long flags;
-
-	/*
-	 * ARC IDE Drivers tries to re-enable interrupts from hard-isr
-	 * context which is simply wrong
-	 */
-	if (in_irq()) {
-		WARN_ONCE(1, "IRQ enabled from hard-isr");
-		return;
-	}
-
-	flags = arch_local_save_flags();
-	flags |= (STATUS_E1_MASK | STATUS_E2_MASK);
-	arch_local_irq_restore(flags);
-}
-#endif
-EXPORT_SYMBOL(arch_local_irq_enable);
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index e095c557afdd..b5426babd3c8 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -166,8 +166,7 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp)
 	 * [L] ZOL loop inhibited to begin with - cleared by a LP insn
 	 * Interrupts enabled
 	 */
-	regs->status32 = STATUS_U_MASK | STATUS_L_MASK |
-			 STATUS_E1_MASK | STATUS_E2_MASK;
+	regs->status32 = STATUS_U_MASK | STATUS_L_MASK | STATUS_IE_MASK;
 
 	/* bogus seed values for debugging */
 	regs->lp_start = 0x10;
-- 
1.9.1

Re: [PATCH 00/19] ARCv2 port to Linux - (A) prepratory patches

[Vineet Gupta]

On Sunday 07 June 2015 02:08 PM, Vineet Gupta wrote:
> Hi,
>
> ARCv2 is the next generation ISA from Synopsys and basis for the
> HS3{4,6,8} families of processors which retain the traditional ARC mantra of
> low power and configurability and are now more performant and feature rich.
>
> Linux has been ported to HS38x series, a 10 stage pipeline core which
> supports MMU (with huge pages) and SMP (upto 4 cores) among other features.
>
>  - www.synopsys.com/dw/ipdir.php?ds=arc-hs38-processor
>  - http://news.synopsys.com/2014-10-14-New-DesignWare-ARC-HS38-Processor-Doubles-Performance-for-Embedded-Linux-Applications
>  - http://www.embedded.com/electronics-news/4435975/Synopsys-ARC-HS38-core-gives-2X-boost-to-Linux-based-apps
>
> This sub-series introduces changes to existing in-tree port of ARC700 core
> (based on ARCompact ISA) to allow for better code sharing with new ARCv2 code.
>
> The actual ARCv2 port will follow as a seperate series.
>
> Please review !

The complete code is also available in git tree

git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc.git  # for-HS-upstream

Thx,
-Vineet