[PATCH 1/2] MIPS: Octeon: Replace rwlocks in irq_chip handlers with raw_spinlocks.

[PATCH 1/2] MIPS: Octeon: Replace rwlocks in irq_chip handlers with raw_spinlocks.

[David Daney]

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
---
 arch/mips/cavium-octeon/octeon-irq.c |   42 +++++++++++----------------------
 1 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c
index 8f4a664..e0e5a59 100644
--- a/arch/mips/cavium-octeon/octeon-irq.c
+++ b/arch/mips/cavium-octeon/octeon-irq.c
@@ -13,8 +13,8 @@
 #include <asm/octeon/cvmx-pexp-defs.h>
 #include <asm/octeon/cvmx-npi-defs.h>
 
-DEFINE_RWLOCK(octeon_irq_ciu0_rwlock);
-DEFINE_RWLOCK(octeon_irq_ciu1_rwlock);
+static DEFINE_RAW_SPINLOCK(octeon_irq_ciu0_lock);
+static DEFINE_RAW_SPINLOCK(octeon_irq_ciu1_lock);
 static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
 
 static int octeon_coreid_for_cpu(int cpu)
@@ -138,19 +138,12 @@ static void octeon_irq_ciu0_enable(unsigned int irq)
 	uint64_t en0;
 	int bit = irq - OCTEON_IRQ_WORKQ0;	/* Bit 0-63 of EN0 */
 
-	/*
-	 * A read lock is used here to make sure only one core is ever
-	 * updating the CIU enable bits at a time. During an enable
-	 * the cores don't interfere with each other. During a disable
-	 * the write lock stops any enables that might cause a
-	 * problem.
-	 */
-	read_lock_irqsave(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu0_lock, flags);
 	en0 = cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
 	en0 |= 1ull << bit;
 	cvmx_write_csr(CVMX_CIU_INTX_EN0(coreid * 2), en0);
 	cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
-	read_unlock_irqrestore(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu0_lock, flags);
 }
 
 static void octeon_irq_ciu0_disable(unsigned int irq)
@@ -159,7 +152,7 @@ static void octeon_irq_ciu0_disable(unsigned int irq)
 	unsigned long flags;
 	uint64_t en0;
 	int cpu;
-	write_lock_irqsave(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu0_lock, flags);
 	for_each_online_cpu(cpu) {
 		int coreid = octeon_coreid_for_cpu(cpu);
 		en0 = cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
@@ -171,7 +164,7 @@ static void octeon_irq_ciu0_disable(unsigned int irq)
 	 * of them are done.
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
-	write_unlock_irqrestore(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu0_lock, flags);
 }
 
 /*
@@ -257,7 +250,7 @@ static int octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *
 	unsigned long flags;
 	int bit = irq - OCTEON_IRQ_WORKQ0;	/* Bit 0-63 of EN0 */
 
-	write_lock_irqsave(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu0_lock, flags);
 	for_each_online_cpu(cpu) {
 		int coreid = octeon_coreid_for_cpu(cpu);
 		uint64_t en0 =
@@ -273,7 +266,7 @@ static int octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *
 	 * of them are done.
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
-	write_unlock_irqrestore(&octeon_irq_ciu0_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu0_lock, flags);
 
 	return 0;
 }
@@ -378,19 +371,12 @@ static void octeon_irq_ciu1_enable(unsigned int irq)
 	uint64_t en1;
 	int bit = irq - OCTEON_IRQ_WDOG0;	/* Bit 0-63 of EN1 */
 
-	/*
-	 * A read lock is used here to make sure only one core is ever
-	 * updating the CIU enable bits at a time.  During an enable
-	 * the cores don't interfere with each other.  During a disable
-	 * the write lock stops any enables that might cause a
-	 * problem.
-	 */
-	read_lock_irqsave(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu1_lock, flags);
 	en1 = cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
 	en1 |= 1ull << bit;
 	cvmx_write_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1), en1);
 	cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
-	read_unlock_irqrestore(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu1_lock, flags);
 }
 
 static void octeon_irq_ciu1_disable(unsigned int irq)
@@ -399,7 +385,7 @@ static void octeon_irq_ciu1_disable(unsigned int irq)
 	unsigned long flags;
 	uint64_t en1;
 	int cpu;
-	write_lock_irqsave(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu1_lock, flags);
 	for_each_online_cpu(cpu) {
 		int coreid = octeon_coreid_for_cpu(cpu);
 		en1 = cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
@@ -411,7 +397,7 @@ static void octeon_irq_ciu1_disable(unsigned int irq)
 	 * of them are done.
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
-	write_unlock_irqrestore(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu1_lock, flags);
 }
 
 /*
@@ -475,7 +461,7 @@ static int octeon_irq_ciu1_set_affinity(unsigned int irq,
 	unsigned long flags;
 	int bit = irq - OCTEON_IRQ_WDOG0;	/* Bit 0-63 of EN1 */
 
-	write_lock_irqsave(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_lock_irqsave(&octeon_irq_ciu1_lock, flags);
 	for_each_online_cpu(cpu) {
 		int coreid = octeon_coreid_for_cpu(cpu);
 		uint64_t en1 =
@@ -492,7 +478,7 @@ static int octeon_irq_ciu1_set_affinity(unsigned int irq,
 	 * of them are done.
 	 */
 	cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
-	write_unlock_irqrestore(&octeon_irq_ciu1_rwlock, flags);
+	raw_spin_unlock_irqrestore(&octeon_irq_ciu1_lock, flags);
 
 	return 0;
 }
-- 
1.6.6

Re: [PATCH 1/2] MIPS: Octeon: Replace rwlocks in irq_chip handlers with raw_spinlocks.

[Ralf Baechle]

On Thu, Feb 18, 2010 at 11:47:40AM -0800, David Daney wrote:

Thanks, queued for 2.6.34 as part of the great locking cleanup.

  Ralf