Merge tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC changes from Vineet Gupta:
 "Mostly cleanup/refactoring in core intc, cache flush, IPI send..."

* tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  mm, arc: remove obsolete pagefault oom killer comment
  ARC: help gcc elide icache helper for !SMP
  ARC: move common ops for line/full cache into helpers
  ARC: cache boot reporting updates
  ARC: [intc] mask/unmask can be hidden again
  ARC: [plat-arcfpga] No need for init_irq hack
  ARC: [intc] don't mask all IRQ by default
  ARC: prune extra header includes from smp.c
  ARC: update some comments
  ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)

13 files changed, 159 insertions, 174 deletions

diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index 355cb47..372466b 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -296,7 +296,7 @@ struct cpuinfo_arc_mmu {
 };
 
 struct cpuinfo_arc_cache {
-	unsigned int sz, line_len, assoc, ver;
+	unsigned int sz_k:8, line_len:8, assoc:4, ver:4, alias:1, vipt:1, pad:6;
 };
 
 struct cpuinfo_arc_ccm {
diff --git a/arch/arc/include/asm/irq.h b/arch/arc/include/asm/irq.h
index fb4efb6..f38652f 100644
--- a/arch/arc/include/asm/irq.h
+++ b/arch/arc/include/asm/irq.h
@@ -16,9 +16,13 @@
 #define TIMER0_IRQ      3
 #define TIMER1_IRQ      4
 
+#include <linux/interrupt.h>
 #include <asm-generic/irq.h>
 
 extern void arc_init_IRQ(void);
 void arc_local_timer_setup(void);
+void arc_request_percpu_irq(int irq, int cpu,
+                            irqreturn_t (*isr)(int irq, void *dev),
+                            const char *irq_nm, void *percpu_dev);
 
 #endif
diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h
index cb7efc2..587df82 100644
--- a/arch/arc/include/asm/irqflags.h
+++ b/arch/arc/include/asm/irqflags.h
@@ -131,24 +131,6 @@ static inline int arch_irqs_disabled(void)
 	return arch_irqs_disabled_flags(arch_local_save_flags());
 }
 
-static inline void arch_mask_irq(unsigned int irq)
-{
-	unsigned int ienb;
-
-	ienb = read_aux_reg(AUX_IENABLE);
-	ienb &= ~(1 << irq);
-	write_aux_reg(AUX_IENABLE, ienb);
-}
-
-static inline void arch_unmask_irq(unsigned int irq)
-{
-	unsigned int ienb;
-
-	ienb = read_aux_reg(AUX_IENABLE);
-	ienb |= (1 << irq);
-	write_aux_reg(AUX_IENABLE, ienb);
-}
-
 #else
 
 #ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index 7d653c0..620ec2f 100644
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -19,21 +19,16 @@
 
 /*
  * 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)
- * -Platform Independent (must for any ARC700)
- * -Needed for each CPU (hence not foldable into init_IRQ)
  *
  * what it does ?
- * -Disable all IRQs (on CPU side)
  * -Optionally, setup the High priority Interrupts as Level 2 IRQs
  */
 void arc_init_IRQ(void)
 {
 	int level_mask = 0;
 
-	/* Disable all IRQs: enable them as devices request */
-	write_aux_reg(AUX_IENABLE, 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;
@@ -60,20 +55,28 @@ void arc_init_IRQ(void)
  * below, per IRQ.
  */
 
-static void arc_mask_irq(struct irq_data *data)
+static void arc_irq_mask(struct irq_data *data)
 {
-	arch_mask_irq(data->irq);
+	unsigned int ienb;
+
+	ienb = read_aux_reg(AUX_IENABLE);
+	ienb &= ~(1 << data->irq);
+	write_aux_reg(AUX_IENABLE, ienb);
 }
 
-static void arc_unmask_irq(struct irq_data *data)
+static void arc_irq_unmask(struct irq_data *data)
 {
-	arch_unmask_irq(data->irq);
+	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_mask_irq,
-	.irq_unmask	= arc_unmask_irq,
+	.irq_mask	= arc_irq_mask,
+	.irq_unmask	= arc_irq_unmask,
 };
 
 static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq,
@@ -150,6 +153,32 @@ void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }
 
+void arc_request_percpu_irq(int irq, int cpu,
+                            irqreturn_t (*isr)(int irq, void *dev),
+                            const char *irq_nm,
+                            void *percpu_dev)
+{
+	/* Boot cpu calls request, all call enable */
+	if (!cpu) {
+		int rc;
+
+		/*
+		 * These 2 calls are essential to making percpu IRQ APIs work
+		 * Ideally these details could be hidden in irq chip map function
+		 * but the issue is IPIs IRQs being static (non-DT) and platform
+		 * specific, so we can't identify them there.
+		 */
+		irq_set_percpu_devid(irq);
+		irq_modify_status(irq, IRQ_NOAUTOEN, 0);  /* @irq, @clr, @set */
+
+		rc = request_percpu_irq(irq, isr, irq_nm, percpu_dev);
+		if (rc)
+			panic("Percpu IRQ request failed for %d\n", irq);
+	}
+
+	enable_percpu_irq(irq, 0);
+}
+
 /*
  * arch_local_irq_enable - Enable interrupts.
  *
diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
index c802bb5..dcd317c 100644
--- a/arch/arc/kernel/smp.c
+++ b/arch/arc/kernel/smp.c
@@ -12,23 +12,15 @@
  *    -- Initial Write (Borrowed heavily from ARM)
  */
 
-#include <linux/module.h>
-#include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/profile.h>
-#include <linux/errno.h>
-#include <linux/err.h>
 #include <linux/mm.h>
 #include <linux/cpu.h>
-#include <linux/smp.h>
 #include <linux/irq.h>
-#include <linux/delay.h>
 #include <linux/atomic.h>
-#include <linux/percpu.h>
 #include <linux/cpumask.h>
-#include <linux/spinlock_types.h>
 #include <linux/reboot.h>
 #include <asm/processor.h>
 #include <asm/setup.h>
@@ -136,7 +128,7 @@ void start_kernel_secondary(void)
 	pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
 
 	if (machine_desc->init_smp)
-		machine_desc->init_smp(smp_processor_id());
+		machine_desc->init_smp(cpu);
 
 	arc_local_timer_setup();
 
@@ -338,18 +330,11 @@ irqreturn_t do_IPI(int irq, void *dev_id)
  */
 static DEFINE_PER_CPU(int, ipi_dev);
 
-static struct irqaction arc_ipi_irq = {
-        .name    = "IPI Interrupt",
-        .flags   = IRQF_PERCPU,
-        .handler = do_IPI,
-};
-
 int smp_ipi_irq_setup(int cpu, int irq)
 {
-	if (!cpu)
-		return setup_irq(irq, &arc_ipi_irq);
-	else
-		arch_unmask_irq(irq);
+	int *dev = per_cpu_ptr(&ipi_dev, cpu);
+
+	arc_request_percpu_irq(irq, cpu, do_IPI, "IPI Interrupt", dev);
 
 	return 0;
 }
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c
index 36c2aa9..dbe74f4 100644
--- a/arch/arc/kernel/time.c
+++ b/arch/arc/kernel/time.c
@@ -144,12 +144,12 @@ static struct clocksource arc_counter = {
 /********** Clock Event Device *********/
 
 /*
- * Arm the timer to interrupt after @limit cycles
+ * Arm the timer to interrupt after @cycles
  * The distinction for oneshot/periodic is done in arc_event_timer_ack() below
  */
-static void arc_timer_event_setup(unsigned int limit)
+static void arc_timer_event_setup(unsigned int cycles)
 {
-	write_aux_reg(ARC_REG_TIMER0_LIMIT, limit);
+	write_aux_reg(ARC_REG_TIMER0_LIMIT, cycles);
 	write_aux_reg(ARC_REG_TIMER0_CNT, 0);	/* start from 0 */
 
 	write_aux_reg(ARC_REG_TIMER0_CTRL, TIMER_CTRL_IE | TIMER_CTRL_NH);
@@ -168,6 +168,10 @@ static void arc_clkevent_set_mode(enum clock_event_mode mode,
 {
 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
+                /*
+                 * At X Hz, 1 sec = 1000ms -> X cycles;
+                 *                    10ms -> X / 100 cycles
+                 */
 		arc_timer_event_setup(arc_get_core_freq() / HZ);
 		break;
 	case CLOCK_EVT_MODE_ONESHOT:
@@ -210,12 +214,6 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static struct irqaction arc_timer_irq = {
-	.name    = "Timer0 (clock-evt-dev)",
-	.flags   = IRQF_TIMER | IRQF_PERCPU,
-	.handler = timer_irq_handler,
-};
-
 /*
  * Setup the local event timer for @cpu
  */
@@ -228,15 +226,9 @@ void arc_local_timer_setup()
 	clockevents_config_and_register(evt, arc_get_core_freq(),
 					0, ARC_TIMER_MAX);
 
-	/*
-	 * setup the per-cpu timer IRQ handler - for all cpus
-	 * For non boot CPU explicitly unmask at intc
-	 * setup_irq() -> .. -> irq_startup() already does this on boot-cpu
-	 */
-	if (!cpu)
-		setup_irq(TIMER0_IRQ, &arc_timer_irq);
-	else
-		arch_unmask_irq(TIMER0_IRQ);
+	/* setup the per-cpu timer IRQ handler - for all cpus */
+	arc_request_percpu_irq(TIMER0_IRQ, cpu, timer_irq_handler,
+			       "Timer0 (per-cpu-tick)", evt);
 }
 
 /*
diff --git a/arch/arc/mm/cache_arc700.c b/arch/arc/mm/cache_arc700.c
index 353b202..4670afc 100644
--- a/arch/arc/mm/cache_arc700.c
+++ b/arch/arc/mm/cache_arc700.c
@@ -77,21 +77,19 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len)
 {
 	int n = 0;
 
-#define PR_CACHE(p, enb, str)						\
-{									\
+#define PR_CACHE(p, cfg, str)						\
 	if (!(p)->ver)							\
 		n += scnprintf(buf + n, len - n, str"\t\t: N/A\n");	\
 	else								\
 		n += scnprintf(buf + n, len - n,			\
-			str"\t\t: (%uK) VIPT, %dway set-asc, %ub Line %s\n", \
-			TO_KB((p)->sz), (p)->assoc, (p)->line_len,	\
-			enb ?  "" : "DISABLED (kernel-build)");		\
-}
+			str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n",	\
+			(p)->sz_k, (p)->assoc, (p)->line_len,		\
+			(p)->vipt ? "VIPT" : "PIPT",			\
+			(p)->alias ? " aliasing" : "",			\
+			IS_ENABLED(cfg) ? "" : " (not used)");
 
-	PR_CACHE(&cpuinfo_arc700[c].icache, IS_ENABLED(CONFIG_ARC_HAS_ICACHE),
-			"I-Cache");
-	PR_CACHE(&cpuinfo_arc700[c].dcache, IS_ENABLED(CONFIG_ARC_HAS_DCACHE),
-			"D-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache");
 
 	return buf;
 }
@@ -116,20 +114,31 @@ void read_decode_cache_bcr(void)
 	p_ic = &cpuinfo_arc700[cpu].icache;
 	READ_BCR(ARC_REG_IC_BCR, ibcr);
 
+	if (!ibcr.ver)
+		goto dc_chk;
+
 	BUG_ON(ibcr.config != 3);
 	p_ic->assoc = 2;		/* Fixed to 2w set assoc */
 	p_ic->line_len = 8 << ibcr.line_len;
-	p_ic->sz = 0x200 << ibcr.sz;
+	p_ic->sz_k = 1 << (ibcr.sz - 1);
 	p_ic->ver = ibcr.ver;
+	p_ic->vipt = 1;
+	p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1;
 
+dc_chk:
 	p_dc = &cpuinfo_arc700[cpu].dcache;
 	READ_BCR(ARC_REG_DC_BCR, dbcr);
 
+	if (!dbcr.ver)
+		return;
+
 	BUG_ON(dbcr.config != 2);
 	p_dc->assoc = 4;		/* Fixed to 4w set assoc */
 	p_dc->line_len = 16 << dbcr.line_len;
-	p_dc->sz = 0x200 << dbcr.sz;
+	p_dc->sz_k = 1 << (dbcr.sz - 1);
 	p_dc->ver = dbcr.ver;
+	p_dc->vipt = 1;
+	p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1;
 }
 
 /*
@@ -142,14 +151,16 @@ void read_decode_cache_bcr(void)
 void arc_cache_init(void)
 {
 	unsigned int __maybe_unused cpu = smp_processor_id();
-	struct cpuinfo_arc_cache __maybe_unused *ic, __maybe_unused *dc;
 	char str[256];
 
 	printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
 
-#ifdef CONFIG_ARC_HAS_ICACHE
-	ic = &cpuinfo_arc700[cpu].icache;
-	if (ic->ver) {
+	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);
@@ -158,26 +169,26 @@ void arc_cache_init(void)
 			panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
 			      ic->ver, CONFIG_ARC_MMU_VER);
 	}
-#endif
 
-#ifdef CONFIG_ARC_HAS_DCACHE
-	dc = &cpuinfo_arc700[cpu].dcache;
-	if (dc->ver) {
-		unsigned int dcache_does_alias;
+	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 */
-		dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
+		handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
 
-		if (dcache_does_alias && !cache_is_vipt_aliasing())
+		if (dc->alias && !handled)
 			panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
-		else if (!dcache_does_alias && cache_is_vipt_aliasing())
+		else if (!dc->alias && handled)
 			panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
 	}
-#endif
 }
 
 #define OP_INV		0x1
@@ -255,10 +266,32 @@ 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 void wait_for_flush(void)
+static unsigned int __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)
+			;
+	}
+
+	return reg;
+}
+
+static void __after_dc_op(const int op, unsigned int reg)
 {
-	while (read_aux_reg(ARC_REG_DC_CTRL) & DC_CTRL_FLUSH_STATUS)
-		;
+	if (op & OP_FLUSH)	/* flush / flush-n-inv both wait */
+		while (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);
 }
 
 /*
@@ -269,18 +302,10 @@ static inline void wait_for_flush(void)
  */
 static inline void __dc_entire_op(const int cacheop)
 {
-	unsigned int tmp = tmp;
+	unsigned int ctrl_reg;
 	int aux;
 
-	if (cacheop == 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
-		 * Default INV sub-mode is DISCARD, which needs to be toggled
-		 */
-		tmp = read_aux_reg(ARC_REG_DC_CTRL);
-		write_aux_reg(ARC_REG_DC_CTRL, tmp | DC_CTRL_INV_MODE_FLUSH);
-	}
+	ctrl_reg = __before_dc_op(cacheop);
 
 	if (cacheop & OP_INV)	/* Inv or flush-n-inv use same cmd reg */
 		aux = ARC_REG_DC_IVDC;
@@ -289,12 +314,7 @@ static inline void __dc_entire_op(const int cacheop)
 
 	write_aux_reg(aux, 0x1);
 
-	if (cacheop & OP_FLUSH)	/* flush / flush-n-inv both wait */
-		wait_for_flush();
-
-	/* Switch back the DISCARD ONLY Invalidate mode */
-	if (cacheop == OP_FLUSH_N_INV)
-		write_aux_reg(ARC_REG_DC_CTRL, tmp & ~DC_CTRL_INV_MODE_FLUSH);
+	__after_dc_op(cacheop, ctrl_reg);
 }
 
 /* For kernel mappings cache operation: index is same as paddr */
@@ -306,29 +326,16 @@ static inline void __dc_entire_op(const int cacheop)
 static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
 				unsigned long sz, const int cacheop)
 {
-	unsigned long flags, tmp = tmp;
+	unsigned long flags;
+	unsigned int ctrl_reg;
 
 	local_irq_save(flags);
 
-	if (cacheop == 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
-		 * Default INV sub-mode is DISCARD, which needs to be toggled
-		 */
-		tmp = read_aux_reg(ARC_REG_DC_CTRL);
-		write_aux_reg(ARC_REG_DC_CTRL, tmp | DC_CTRL_INV_MODE_FLUSH);
-	}
+	ctrl_reg = __before_dc_op(cacheop);
 
 	__cache_line_loop(paddr, vaddr, sz, cacheop);
 
-	if (cacheop & OP_FLUSH)	/* flush / flush-n-inv both wait */
-		wait_for_flush();
-
-	/* Switch back the DISCARD ONLY Invalidate mode */
-	if (cacheop == OP_FLUSH_N_INV)
-		write_aux_reg(ARC_REG_DC_CTRL, tmp & ~DC_CTRL_INV_MODE_FLUSH);
+	__after_dc_op(cacheop, ctrl_reg);
 
 	local_irq_restore(flags);
 }
@@ -389,8 +396,16 @@ static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
 /***********************************************************
  * Machine specific helper for per line I-Cache invalidate.
  */
-static void __ic_line_inv_vaddr_local(unsigned long paddr, unsigned long vaddr,
-				unsigned long sz)
+
+static inline void __ic_entire_inv(void)
+{
+	write_aux_reg(ARC_REG_IC_IVIC, 1);
+	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
+}
+
+static inline void
+__ic_line_inv_vaddr_local(unsigned long paddr, unsigned long vaddr,
+			  unsigned long sz)
 {
 	unsigned long flags;
 
@@ -399,30 +414,39 @@ static void __ic_line_inv_vaddr_local(unsigned long paddr, unsigned long vaddr,
 	local_irq_restore(flags);
 }
 
-static inline void __ic_entire_inv(void)
-{
-	write_aux_reg(ARC_REG_IC_IVIC, 1);
-	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
-}
+#ifndef CONFIG_SMP
+
+#define __ic_line_inv_vaddr(p, v, s)	__ic_line_inv_vaddr_local(p, v, s)
 
-struct ic_line_inv_vaddr_ipi {
+#else
+
+struct ic_inv_args {
 	unsigned long paddr, vaddr;
 	int sz;
 };
 
 static void __ic_line_inv_vaddr_helper(void *info)
 {
-        struct ic_line_inv_vaddr_ipi *ic_inv = (struct ic_line_inv_vaddr_ipi*) info;
+        struct ic_inv *ic_inv_args = (struct ic_inv_args *) info;
+
         __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz);
 }
 
 static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
 				unsigned long sz)
 {
-	struct ic_line_inv_vaddr_ipi ic_inv = { paddr, vaddr , sz};
+	struct ic_inv_args ic_inv = {
+		.paddr = paddr,
+		.vaddr = vaddr,
+		.sz    = sz
+	};
+
 	on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1);
 }
-#else
+
+#endif	/* CONFIG_SMP */
+
+#else	/* !CONFIG_ARC_HAS_ICACHE */
 
 #define __ic_entire_inv()
 #define __ic_line_inv_vaddr(pstart, vstart, sz)
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 9c69552..6f7e3a6 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -159,7 +159,6 @@ good_area:
 		return;
 	}
 
-	/* TBD: switch to pagefault_out_of_memory() */
 	if (fault & VM_FAULT_OOM)
 		goto out_of_memory;
 	else if (fault & VM_FAULT_SIGBUS)
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index 79bfc81..d572f1c 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -220,9 +220,9 @@ ex_saved_reg1:
 
 .macro CONV_PTE_TO_TLB
 	and    r3, r0, PTE_BITS_RWX	;       r w x
-	lsl    r2, r3, 3		; r w x 0 0 0
+	lsl    r2, r3, 3		; r w x 0 0 0 (GLOBAL, kernel only)
 	and.f  0,  r0, _PAGE_GLOBAL
-	or.z   r2, r2, r3		; r w x r w x
+	or.z   r2, r2, r3		; r w x r w x (!GLOBAL, user page)
 
 	and r3, r0, PTE_BITS_NON_RWX_IN_PD1 ; Extract PFN+cache bits from PTE
 	or  r3, r3, r2
diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
index 4d1bddc..66fd0ec 100644
--- a/arch/arc/plat-arcfpga/Makefile
+++ b/arch/arc/plat-arcfpga/Makefile
@@ -8,5 +8,5 @@
 
 KBUILD_CFLAGS	+= -Iarch/arc/plat-arcfpga/include
 
-obj-y := platform.o irq.o
+obj-y := platform.o
 obj-$(CONFIG_ISS_SMP_EXTN)		+= smp.o
diff --git a/arch/arc/plat-arcfpga/include/plat/irq.h b/arch/arc/plat-arcfpga/include/plat/irq.h
index 6adbc53..2c9dea6 100644
--- a/arch/arc/plat-arcfpga/include/plat/irq.h
+++ b/arch/arc/plat-arcfpga/include/plat/irq.h
@@ -24,6 +24,4 @@
 #define IDU_INTERRUPT_0 16
 #endif
 
-extern void __init plat_fpga_init_IRQ(void);
-
 #endif
diff --git a/arch/arc/plat-arcfpga/irq.c b/arch/arc/plat-arcfpga/irq.c
deleted file mode 100644
index d2215fd..0000000
--- a/arch/arc/plat-arcfpga/irq.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * ARC FPGA Platform IRQ hookups
- *
- * Copyright (C) 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.
- */
-
-#include <linux/interrupt.h>
-#include <plat/irq.h>
-
-void __init plat_fpga_init_IRQ(void)
-{
-	/*
-	 * SMP Hack because UART IRQ hardwired to cpu0 (boot-cpu) but if the
-	 * request_irq() comes from any other CPU, the low level IRQ unamsking
-	 * essential for getting Interrupts won't be enabled on cpu0, locking
-	 * up the UART state machine.
-	 */
-#ifdef CONFIG_SMP
-	arch_unmask_irq(UART0_IRQ);
-#endif
-}
diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
index b8d0d45..1038949 100644
--- a/arch/arc/plat-arcfpga/platform.c
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -57,7 +57,6 @@ MACHINE_START(ANGEL4, "angel4")
 	.dt_compat	= aa4_compat,
 	.init_early	= plat_fpga_early_init,
 	.init_machine	= plat_fpga_populate_dev,
-	.init_irq	= plat_fpga_init_IRQ,
 #ifdef CONFIG_ISS_SMP_EXTN
 	.init_smp	= iss_model_init_smp,
 #endif
@@ -72,7 +71,6 @@ MACHINE_START(ML509, "ml509")
 	.dt_compat	= ml509_compat,
 	.init_early	= plat_fpga_early_init,
 	.init_machine	= plat_fpga_populate_dev,
-	.init_irq	= plat_fpga_init_IRQ,
 #ifdef CONFIG_SMP
 	.init_smp	= iss_model_init_smp,
 #endif
@@ -87,5 +85,4 @@ MACHINE_START(NSIMOSCI, "nsimosci")
 	.dt_compat	= nsimosci_compat,
 	.init_early	= NULL,
 	.init_machine	= plat_fpga_populate_dev,
-	.init_irq	= NULL,
 MACHINE_END