Openwrt/target/linux/brcm63xx/patches-3.9/319-MIPS-BCM63XX-protect-irq-register-accesses.patch

From 05e32e9dc84ee96728596c0b8b86de7eae8de229 Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jogo@openwrt.org>
Date: Sun, 21 Apr 2013 15:38:56 +0200
Subject: [PATCH 11/14] MIPS: BCM63XX: protect irq register accesses

---
 arch/mips/bcm63xx/irq.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

--- a/arch/mips/bcm63xx/irq.c
+++ b/arch/mips/bcm63xx/irq.c
@@ -12,6 +12,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/irq.h>
+#include <linux/spinlock.h>
 #include <asm/irq_cpu.h>
 #include <asm/mipsregs.h>
 #include <bcm63xx_cpu.h>
@@ -26,6 +27,9 @@ static void __internal_irq_mask_64(unsig
 static void __internal_irq_unmask_32(unsigned int irq) __maybe_unused;
 static void __internal_irq_unmask_64(unsigned int irq) __maybe_unused;
 
+static DEFINE_SPINLOCK(ipic_lock);
+static DEFINE_SPINLOCK(epic_lock);
+
 #ifndef BCMCPU_RUNTIME_DETECT
 #ifdef CONFIG_BCM63XX_CPU_3368
 #define irq_stat_reg0		PERF_IRQSTAT_3368_REG
@@ -324,8 +328,10 @@ void __dispatch_internal_##width(int cpu
 	u32 irq_stat_addr = get_irq_stat_addr(cpu);			\
 	u32 irq_mask_addr = get_irq_mask_addr(cpu);			\
 	int *next = &i[cpu];						\
+	unsigned long flags;						\
 									\
 	/* read registers in reverse order */				\
+	spin_lock_irqsave(&ipic_lock, flags);				\
 	for (src = 0, tgt = (width / 32); src < (width / 32); src++) {	\
 		u32 val;						\
 									\
@@ -336,6 +342,7 @@ void __dispatch_internal_##width(int cpu
 		if (val)						\
 			irqs_pending = true;				\
 	}								\
+	spin_unlock_irqrestore(&ipic_lock, flags);			\
 									\
 	if (!irqs_pending)						\
 		return;							\
@@ -357,10 +364,13 @@ static void __internal_irq_mask_##width(
 	unsigned reg = (irq / 32) ^ (width/32 - 1);			\
 	unsigned bit = irq & 0x1f;					\
 	u32 irq_mask_addr = get_irq_mask_addr(0);			\
+	unsigned long flags;						\
 									\
+	spin_lock_irqsave(&ipic_lock, flags);				\
 	val = bcm_readl(irq_mask_addr + reg * sizeof(u32));		\
 	val &= ~(1 << bit);						\
 	bcm_writel(val, irq_mask_addr + reg * sizeof(u32));		\
+	spin_unlock_irqrestore(&ipic_lock, flags);			\
 }									\
 									\
 static void __internal_irq_unmask_##width(unsigned int irq)		\
@@ -369,10 +379,13 @@ static void __internal_irq_unmask_##widt
 	unsigned reg = (irq / 32) ^ (width/32 - 1);			\
 	unsigned bit = irq & 0x1f; 					\
 	u32 irq_mask_addr = get_irq_mask_addr(0);			\
+	unsigned long flags;						\
 									\
+	spin_lock_irqsave(&ipic_lock, flags);				\
 	val = bcm_readl(irq_mask_addr + reg * sizeof(u32));		\
 	val |= (1 << bit); 						\
 	bcm_writel(val, irq_mask_addr + reg * sizeof(u32));		\
+	spin_unlock_irqrestore(&ipic_lock, flags);			\
 }
 
 BUILD_IPIC_INTERNAL(32);
@@ -431,8 +444,10 @@ static void bcm63xx_external_irq_mask(st
 {
 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 	u32 reg, regaddr;
+	unsigned long flags;
 
 	regaddr = get_ext_irq_perf_reg(irq);
+	spin_lock_irqsave(&epic_lock, flags);
 	reg = bcm_perf_readl(regaddr);
 
 	if (BCMCPU_IS_6348())
@@ -441,6 +456,8 @@ static void bcm63xx_external_irq_mask(st
 		reg &= ~EXTIRQ_CFG_MASK(irq % 4);
 
 	bcm_perf_writel(reg, regaddr);
+	spin_unlock_irqrestore(&epic_lock, flags);
+
 	if (is_ext_irq_cascaded)
 		internal_irq_mask(irq + ext_irq_start);
 }
@@ -449,8 +466,10 @@ static void bcm63xx_external_irq_unmask(
 {
 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 	u32 reg, regaddr;
+	unsigned long flags;
 
 	regaddr = get_ext_irq_perf_reg(irq);
+	spin_lock_irqsave(&epic_lock, flags);
 	reg = bcm_perf_readl(regaddr);
 
 	if (BCMCPU_IS_6348())
@@ -459,6 +478,7 @@ static void bcm63xx_external_irq_unmask(
 		reg |= EXTIRQ_CFG_MASK(irq % 4);
 
 	bcm_perf_writel(reg, regaddr);
+	spin_unlock_irqrestore(&epic_lock, flags);
 
 	if (is_ext_irq_cascaded)
 		internal_irq_unmask(irq + ext_irq_start);
@@ -468,8 +488,10 @@ static void bcm63xx_external_irq_clear(s
 {
 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 	u32 reg, regaddr;
+	unsigned long flags;
 
 	regaddr = get_ext_irq_perf_reg(irq);
+	spin_lock_irqsave(&epic_lock, flags);
 	reg = bcm_perf_readl(regaddr);
 
 	if (BCMCPU_IS_6348())
@@ -478,6 +500,7 @@ static void bcm63xx_external_irq_clear(s
 		reg |= EXTIRQ_CFG_CLEAR(irq % 4);
 
 	bcm_perf_writel(reg, regaddr);
+	spin_unlock_irqrestore(&epic_lock, flags);
 }
 
 static int bcm63xx_external_irq_set_type(struct irq_data *d,
@@ -486,6 +509,7 @@ static int bcm63xx_external_irq_set_type
 	unsigned int irq = d->irq - IRQ_EXTERNAL_BASE;
 	u32 reg, regaddr;
 	int levelsense, sense, bothedge;
+	unsigned long flags;
 
 	flow_type &= IRQ_TYPE_SENSE_MASK;
 
@@ -520,6 +544,7 @@ static int bcm63xx_external_irq_set_type
 	}
 
 	regaddr = get_ext_irq_perf_reg(irq);
+	spin_lock_irqsave(&epic_lock, flags);
 	reg = bcm_perf_readl(regaddr);
 	irq %= 4;
 
@@ -564,6 +589,7 @@ static int bcm63xx_external_irq_set_type
 	}
 
 	bcm_perf_writel(reg, regaddr);
+	spin_unlock_irqrestore(&epic_lock, flags);
 
 	irqd_set_trigger_type(d, flow_type);
 	if (flow_type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))