[PATCH 00/10] MIPS CPC fixup and CPU Idle for MIPSr6 CPUs

[PATCH 00/10] MIPS CPC fixup and CPU Idle for MIPSr6 CPUs

[Matt Redfearn]

This series fixes a small issue with the CPC driver when A CM3 is
present, where a redundant lock was taken.

There are then additions to the pm-cps driver to add support for R6 CPUs
such as the I6400, and additionally the CM3 present in the I6400.

Finally we enable the cpuidle-cps driver for MIPSr6 CPUs.

Applies atop v4.8-rc4



Matt Redfearn (10):
  MIPS: CPC: Convert bare 'unsigned' to 'unsigned int'
  MIPS: CPC: Avoid lock when MIPS CM >= 3 is present
  MIPS: pm-cps: Change FSB workaround to CPU blacklist
  MIPS: pm-cps: Remove I6400 sync types
  MIPS: pm-cps: Add P6600 implementation lightweight sync types
  MIPS: pm-cps: Use MIPS standard lightweight ordering barrier
  MIPS: pm-cps: Add MIPSr6 CPU support
  MIPS: pm-cps: Support CM3 changes to Coherence Enable Register
  MIPS: SMP: Wrap call to mips_cpc_lock_other in mips_cm_lock_other
  cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs.

 arch/mips/include/asm/barrier.h | 10 ++++++
 arch/mips/include/asm/mips-cm.h |  1 +
 arch/mips/include/asm/pm-cps.h  |  6 ++--
 arch/mips/kernel/mips-cpc.c     | 17 +++++++++--
 arch/mips/kernel/pm-cps.c       | 67 ++++++++++++++++++++++++-----------------
 arch/mips/kernel/smp.c          |  2 ++
 drivers/cpuidle/Kconfig.mips    |  2 +-
 drivers/cpuidle/cpuidle-cps.c   |  2 +-
 8 files changed, 73 insertions(+), 34 deletions(-)

-- 
2.7.4

[PATCH 00/10] MIPS CPC fixup and CPU Idle for MIPSr6 CPUs

[Matt Redfearn]

This series fixes a small issue with the CPC driver when A CM3 is
present, where a redundant lock was taken.

There are then additions to the pm-cps driver to add support for R6 CPUs
such as the I6400, and additionally the CM3 present in the I6400.

Finally we enable the cpuidle-cps driver for MIPSr6 CPUs.

Applies atop v4.8-rc4



Matt Redfearn (10):
  MIPS: CPC: Convert bare 'unsigned' to 'unsigned int'
  MIPS: CPC: Avoid lock when MIPS CM >= 3 is present
  MIPS: pm-cps: Change FSB workaround to CPU blacklist
  MIPS: pm-cps: Remove I6400 sync types
  MIPS: pm-cps: Add P6600 implementation lightweight sync types
  MIPS: pm-cps: Use MIPS standard lightweight ordering barrier
  MIPS: pm-cps: Add MIPSr6 CPU support
  MIPS: pm-cps: Support CM3 changes to Coherence Enable Register
  MIPS: SMP: Wrap call to mips_cpc_lock_other in mips_cm_lock_other
  cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs.

 arch/mips/include/asm/barrier.h | 10 ++++++
 arch/mips/include/asm/mips-cm.h |  1 +
 arch/mips/include/asm/pm-cps.h  |  6 ++--
 arch/mips/kernel/mips-cpc.c     | 17 +++++++++--
 arch/mips/kernel/pm-cps.c       | 67 ++++++++++++++++++++++++-----------------
 arch/mips/kernel/smp.c          |  2 ++
 drivers/cpuidle/Kconfig.mips    |  2 +-
 drivers/cpuidle/cpuidle-cps.c   |  2 +-
 8 files changed, 73 insertions(+), 34 deletions(-)

-- 
2.7.4

[PATCH 00/10] MIPS CPC fixup and CPU Idle for MIPSr6 CPUs

[Matt Redfearn]

This series fixes a small issue with the CPC driver when A CM3 is
present, where a redundant lock was taken.

There are then additions to the pm-cps driver to add support for R6 CPUs
such as the I6400, and additionally the CM3 present in the I6400.

Finally we enable the cpuidle-cps driver for MIPSr6 CPUs.

Applies atop v4.8-rc4



Matt Redfearn (10):
  MIPS: CPC: Convert bare 'unsigned' to 'unsigned int'
  MIPS: CPC: Avoid lock when MIPS CM >= 3 is present
  MIPS: pm-cps: Change FSB workaround to CPU blacklist
  MIPS: pm-cps: Remove I6400 sync types
  MIPS: pm-cps: Add P6600 implementation lightweight sync types
  MIPS: pm-cps: Use MIPS standard lightweight ordering barrier
  MIPS: pm-cps: Add MIPSr6 CPU support
  MIPS: pm-cps: Support CM3 changes to Coherence Enable Register
  MIPS: SMP: Wrap call to mips_cpc_lock_other in mips_cm_lock_other
  cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs.

 arch/mips/include/asm/barrier.h | 10 ++++++
 arch/mips/include/asm/mips-cm.h |  1 +
 arch/mips/include/asm/pm-cps.h  |  6 ++--
 arch/mips/kernel/mips-cpc.c     | 17 +++++++++--
 arch/mips/kernel/pm-cps.c       | 67 ++++++++++++++++++++++++-----------------
 arch/mips/kernel/smp.c          |  2 ++
 drivers/cpuidle/Kconfig.mips    |  2 +-
 drivers/cpuidle/cpuidle-cps.c   |  2 +-
 8 files changed, 73 insertions(+), 34 deletions(-)

-- 
2.7.4

[PATCH 01/10] MIPS: CPC: Convert bare 'unsigned' to 'unsigned int'

[Matt Redfearn]

Checkpatch complains about use of bare unsigned type.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/mips-cpc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 566b8d2c092c..0e337f55ac60 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -52,7 +52,7 @@ static phys_addr_t mips_cpc_phys_base(void)
 int mips_cpc_probe(void)
 {
 	phys_addr_t addr;
-	unsigned cpu;
+	unsigned int cpu;
 
 	for_each_possible_cpu(cpu)
 		spin_lock_init(&per_cpu(cpc_core_lock, cpu));
@@ -70,7 +70,7 @@ int mips_cpc_probe(void)
 
 void mips_cpc_lock_other(unsigned int core)
 {
-	unsigned curr_core;
+	unsigned int curr_core;
 	preempt_disable();
 	curr_core = current_cpu_data.core;
 	spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
@@ -86,7 +86,7 @@ void mips_cpc_lock_other(unsigned int core)
 
 void mips_cpc_unlock_other(void)
 {
-	unsigned curr_core = current_cpu_data.core;
+	unsigned int curr_core = current_cpu_data.core;
 	spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
 			       per_cpu(cpc_core_lock_flags, curr_core));
 	preempt_enable();
-- 
2.7.4

[PATCH 01/10] MIPS: CPC: Convert bare 'unsigned' to 'unsigned int'

[Matt Redfearn]

Checkpatch complains about use of bare unsigned type.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/mips-cpc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 566b8d2c092c..0e337f55ac60 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -52,7 +52,7 @@ static phys_addr_t mips_cpc_phys_base(void)
 int mips_cpc_probe(void)
 {
 	phys_addr_t addr;
-	unsigned cpu;
+	unsigned int cpu;
 
 	for_each_possible_cpu(cpu)
 		spin_lock_init(&per_cpu(cpc_core_lock, cpu));
@@ -70,7 +70,7 @@ int mips_cpc_probe(void)
 
 void mips_cpc_lock_other(unsigned int core)
 {
-	unsigned curr_core;
+	unsigned int curr_core;
 	preempt_disable();
 	curr_core = current_cpu_data.core;
 	spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
@@ -86,7 +86,7 @@ void mips_cpc_lock_other(unsigned int core)
 
 void mips_cpc_unlock_other(void)
 {
-	unsigned curr_core = current_cpu_data.core;
+	unsigned int curr_core = current_cpu_data.core;
 	spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
 			       per_cpu(cpc_core_lock_flags, curr_core));
 	preempt_enable();
-- 
2.7.4

[PATCH 02/10] MIPS: CPC: Avoid lock when MIPS CM >= 3 is present

[Matt Redfearn]

MIPS CM version 3 removed the CPC_CL_OTHER register and instead the
CM_CL_OTHER register is used to redirect the CPC_OTHER region. As such,
we should not write the unimplmented register and can avoid the
spinlock as well.
These lock functions should aleady be called within the context of a
mips_cm_{lock,unlock}_other pair ensuring the correct CPC_OTHER region
will be accessed.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/mips-cpc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 0e337f55ac60..2a45867d3b4f 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -71,6 +71,11 @@ int mips_cpc_probe(void)
 void mips_cpc_lock_other(unsigned int core)
 {
 	unsigned int curr_core;
+
+	if (mips_cm_revision() >= CM_REV_CM3)
+		/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
+		return;
+
 	preempt_disable();
 	curr_core = current_cpu_data.core;
 	spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
@@ -86,7 +91,13 @@ void mips_cpc_lock_other(unsigned int core)
 
 void mips_cpc_unlock_other(void)
 {
-	unsigned int curr_core = current_cpu_data.core;
+	unsigned int curr_core;
+
+	if (mips_cm_revision() >= CM_REV_CM3)
+		/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
+		return;
+
+	curr_core = current_cpu_data.core;
 	spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
 			       per_cpu(cpc_core_lock_flags, curr_core));
 	preempt_enable();
-- 
2.7.4

[PATCH 02/10] MIPS: CPC: Avoid lock when MIPS CM >= 3 is present

[Matt Redfearn]

MIPS CM version 3 removed the CPC_CL_OTHER register and instead the
CM_CL_OTHER register is used to redirect the CPC_OTHER region. As such,
we should not write the unimplmented register and can avoid the
spinlock as well.
These lock functions should aleady be called within the context of a
mips_cm_{lock,unlock}_other pair ensuring the correct CPC_OTHER region
will be accessed.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/mips-cpc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c
index 0e337f55ac60..2a45867d3b4f 100644
--- a/arch/mips/kernel/mips-cpc.c
+++ b/arch/mips/kernel/mips-cpc.c
@@ -71,6 +71,11 @@ int mips_cpc_probe(void)
 void mips_cpc_lock_other(unsigned int core)
 {
 	unsigned int curr_core;
+
+	if (mips_cm_revision() >= CM_REV_CM3)
+		/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
+		return;
+
 	preempt_disable();
 	curr_core = current_cpu_data.core;
 	spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core),
@@ -86,7 +91,13 @@ void mips_cpc_lock_other(unsigned int core)
 
 void mips_cpc_unlock_other(void)
 {
-	unsigned int curr_core = current_cpu_data.core;
+	unsigned int curr_core;
+
+	if (mips_cm_revision() >= CM_REV_CM3)
+		/* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */
+		return;
+
+	curr_core = current_cpu_data.core;
 	spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core),
 			       per_cpu(cpc_core_lock_flags, curr_core));
 	preempt_enable();
-- 
2.7.4

[PATCH 03/10] MIPS: pm-cps: Change FSB workaround to CPU blacklist

[Matt Redfearn]

The check for whether a CPU required the FSB flush workaround
previously required every CPU not requiring it to be whitelisted. That
approach does not scale well as new CPUs are introduced so change the
default from a WARN and returning an error to just returning 0. Any CPUs
requiring the workaround can then be added to the blacklist.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 5b31a9405ebc..2faa227a032e 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -272,14 +272,9 @@ static int __init cps_gen_flush_fsb(u32 **pp, struct uasm_label **pl,
 		/* On older ones it's unavailable */
 		return -1;
 
-	/* CPUs which do not require the workaround */
-	case CPU_P5600:
-	case CPU_I6400:
-		return 0;
-
 	default:
-		WARN_ONCE(1, "pm-cps: FSB flush unsupported for this CPU\n");
-		return -1;
+		/* Assume that the CPU does not need this workaround */
+		return 0;
 	}
 
 	/*
-- 
2.7.4

[PATCH 03/10] MIPS: pm-cps: Change FSB workaround to CPU blacklist

[Matt Redfearn]

The check for whether a CPU required the FSB flush workaround
previously required every CPU not requiring it to be whitelisted. That
approach does not scale well as new CPUs are introduced so change the
default from a WARN and returning an error to just returning 0. Any CPUs
requiring the workaround can then be added to the blacklist.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 5b31a9405ebc..2faa227a032e 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -272,14 +272,9 @@ static int __init cps_gen_flush_fsb(u32 **pp, struct uasm_label **pl,
 		/* On older ones it's unavailable */
 		return -1;
 
-	/* CPUs which do not require the workaround */
-	case CPU_P5600:
-	case CPU_I6400:
-		return 0;
-
 	default:
-		WARN_ONCE(1, "pm-cps: FSB flush unsupported for this CPU\n");
-		return -1;
+		/* Assume that the CPU does not need this workaround */
+		return 0;
 	}
 
 	/*
-- 
2.7.4

[PATCH 04/10] MIPS: pm-cps: Remove I6400 sync types

[Matt Redfearn]

Commit 4e88a8621301 ("MIPS: Add cases for CPU_I6400") added a case for
I6400 to the selection of lightweight sync types, but these are not
implemented. Remove the case.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 2faa227a032e..c6b9ad2256f0 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -674,7 +674,6 @@ static int __init cps_pm_init(void)
 	case CPU_PROAPTIV:
 	case CPU_M5150:
 	case CPU_P5600:
-	case CPU_I6400:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
 		stype_ordering = 0x10;
-- 
2.7.4

[PATCH 04/10] MIPS: pm-cps: Remove I6400 sync types

[Matt Redfearn]

Commit 4e88a8621301 ("MIPS: Add cases for CPU_I6400") added a case for
I6400 to the selection of lightweight sync types, but these are not
implemented. Remove the case.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 2faa227a032e..c6b9ad2256f0 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -674,7 +674,6 @@ static int __init cps_pm_init(void)
 	case CPU_PROAPTIV:
 	case CPU_M5150:
 	case CPU_P5600:
-	case CPU_I6400:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
 		stype_ordering = 0x10;
-- 
2.7.4

[PATCH 05/10] MIPS: pm-cps: Add P6600 implementation lightweight sync types

[Matt Redfearn]

P6600 implements the same lightweight sync types as previous CPUs.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index c6b9ad2256f0..f8c8edd0a451 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -674,6 +674,7 @@ static int __init cps_pm_init(void)
 	case CPU_PROAPTIV:
 	case CPU_M5150:
 	case CPU_P5600:
+	case CPU_P6600:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
 		stype_ordering = 0x10;
-- 
2.7.4

[PATCH 05/10] MIPS: pm-cps: Add P6600 implementation lightweight sync types

[Matt Redfearn]

P6600 implements the same lightweight sync types as previous CPUs.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/pm-cps.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index c6b9ad2256f0..f8c8edd0a451 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -674,6 +674,7 @@ static int __init cps_pm_init(void)
 	case CPU_PROAPTIV:
 	case CPU_M5150:
 	case CPU_P5600:
+	case CPU_P6600:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
 		stype_ordering = 0x10;
-- 
2.7.4

[PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but
architecturally defined ordering barrier. If a CPU does not implement it,
the arch specifies that it must fall back to SYNC(0).

Define the barrier type and always use it in the pm-cps code rather than
falling back to the heavyweight sync(0) such that we can benefit from
the lighter weight sync.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/barrier.h | 10 ++++++++++
 arch/mips/kernel/pm-cps.c       |  3 +--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
index d296633d890e..90c7a97db7e1 100644
--- a/arch/mips/include/asm/barrier.h
+++ b/arch/mips/include/asm/barrier.h
@@ -10,6 +10,16 @@
 
 #include <asm/addrspace.h>
 
+/*
+ * Lightweight sync types defined by the MIPS architecture
+ * These values are used with the sync instruction to perform memory barriers
+ * other than the standard heavyweight sync(0) completion barrier.
+ */
+
+/* Lightweight ordering barrier */
+#define STYPE_SYNC_MB 0x10
+
+
 #ifdef CONFIG_CPU_HAS_SYNC
 #define __sync()				\
 	__asm__ __volatile__(			\
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index f8c8edd0a451..572dc1d016a0 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -76,7 +76,7 @@ static struct uasm_reloc relocs[32] __initdata;
 /* CPU dependant sync types */
 static unsigned stype_intervention;
 static unsigned stype_memory;
-static unsigned stype_ordering;
+static unsigned stype_ordering = STYPE_SYNC_MB;
 
 enum mips_reg {
 	zero, at, v0, v1, a0, a1, a2, a3,
@@ -677,7 +677,6 @@ static int __init cps_pm_init(void)
 	case CPU_P6600:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
-		stype_ordering = 0x10;
 		break;
 
 	default:
-- 
2.7.4

[PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but
architecturally defined ordering barrier. If a CPU does not implement it,
the arch specifies that it must fall back to SYNC(0).

Define the barrier type and always use it in the pm-cps code rather than
falling back to the heavyweight sync(0) such that we can benefit from
the lighter weight sync.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/barrier.h | 10 ++++++++++
 arch/mips/kernel/pm-cps.c       |  3 +--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
index d296633d890e..90c7a97db7e1 100644
--- a/arch/mips/include/asm/barrier.h
+++ b/arch/mips/include/asm/barrier.h
@@ -10,6 +10,16 @@
 
 #include <asm/addrspace.h>
 
+/*
+ * Lightweight sync types defined by the MIPS architecture
+ * These values are used with the sync instruction to perform memory barriers
+ * other than the standard heavyweight sync(0) completion barrier.
+ */
+
+/* Lightweight ordering barrier */
+#define STYPE_SYNC_MB 0x10
+
+
 #ifdef CONFIG_CPU_HAS_SYNC
 #define __sync()				\
 	__asm__ __volatile__(			\
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index f8c8edd0a451..572dc1d016a0 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -76,7 +76,7 @@ static struct uasm_reloc relocs[32] __initdata;
 /* CPU dependant sync types */
 static unsigned stype_intervention;
 static unsigned stype_memory;
-static unsigned stype_ordering;
+static unsigned stype_ordering = STYPE_SYNC_MB;
 
 enum mips_reg {
 	zero, at, v0, v1, a0, a1, a2, a3,
@@ -677,7 +677,6 @@ static int __init cps_pm_init(void)
 	case CPU_P6600:
 		stype_intervention = 0x2;
 		stype_memory = 0x3;
-		stype_ordering = 0x10;
 		break;
 
 	default:
-- 
2.7.4

[PATCH 07/10] MIPS: pm-cps: Add MIPSr6 CPU support

[Matt Redfearn]

This patch adds support for CPUs implementing the MIPSr6 ISA to the CPS
power management code. Three changes are necessary:

1. In MIPSr6, coupled coherence is necessary when CPUS implement multiple
   Virtual Processors (VPs).

2. MIPSr6 virtual processors are more like real cores and cannot yield
   to other VPs on the same core, so drop the MT ASE yield instruction.

3. To halt a MIPSr6 VP, the CPC VP_STOP register is used rather than the
   MT ASE TCHalt CP0 register.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/pm-cps.h |  6 ++++--
 arch/mips/kernel/pm-cps.c      | 22 ++++++++++++++++++----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/mips/include/asm/pm-cps.h b/arch/mips/include/asm/pm-cps.h
index 625eda53d571..89d58d80b77b 100644
--- a/arch/mips/include/asm/pm-cps.h
+++ b/arch/mips/include/asm/pm-cps.h
@@ -13,10 +13,12 @@
 
 /*
  * The CM & CPC can only handle coherence & power control on a per-core basis,
- * thus in an MT system the VPEs within each core are coupled and can only
+ * thus in an MT system the VP(E)s within each core are coupled and can only
  * enter or exit states requiring CM or CPC assistance in unison.
  */
-#ifdef CONFIG_MIPS_MT
+#if defined(CONFIG_CPU_MIPSR6)
+# define coupled_coherence cpu_has_vp
+#elif defined(CONFIG_MIPS_MT)
 # define coupled_coherence cpu_has_mipsmt
 #else
 # define coupled_coherence 0
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 572dc1d016a0..11c951f4f0b9 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -134,7 +134,7 @@ int cps_pm_enter_state(enum cps_pm_state state)
 		return -EINVAL;
 
 	/* Calculate which coupled CPUs (VPEs) are online */
-#ifdef CONFIG_MIPS_MT
+#if defined(CONFIG_MIPS_MT) || defined(CONFIG_CPU_MIPSR6)
 	if (cpu_online(cpu)) {
 		cpumask_and(coupled_mask, cpu_online_mask,
 			    &cpu_sibling_map[cpu]);
@@ -436,7 +436,8 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 			uasm_i_lw(&p, t0, 0, r_nc_count);
 			uasm_il_bltz(&p, &r, t0, lbl_secondary_cont);
 			uasm_i_ehb(&p);
-			uasm_i_yield(&p, zero, t1);
+			if (cpu_has_mipsmt)
+				uasm_i_yield(&p, zero, t1);
 			uasm_il_b(&p, &r, lbl_poll_cont);
 			uasm_i_nop(&p);
 		} else {
@@ -444,8 +445,21 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 			 * The core will lose power & this VPE will not continue
 			 * so it can simply halt here.
 			 */
-			uasm_i_addiu(&p, t0, zero, TCHALT_H);
-			uasm_i_mtc0(&p, t0, 2, 4);
+			if (cpu_has_mipsmt) {
+				/* Halt the VPE via C0 tchalt register */
+				uasm_i_addiu(&p, t0, zero, TCHALT_H);
+				uasm_i_mtc0(&p, t0, 2, 4);
+			} else if (cpu_has_vp) {
+				/* Halt the VP via the CPC VP_STOP register */
+				unsigned int vpe_id;
+
+				vpe_id = cpu_vpe_id(&cpu_data[cpu]);
+				uasm_i_addiu(&p, t0, zero, 1 << vpe_id);
+				UASM_i_LA(&p, t1, (long)addr_cpc_cl_vp_stop());
+				uasm_i_sw(&p, t0, 0, t1);
+			} else {
+				BUG();
+			}
 			uasm_build_label(&l, p, lbl_secondary_hang);
 			uasm_il_b(&p, &r, lbl_secondary_hang);
 			uasm_i_nop(&p);
-- 
2.7.4

[PATCH 07/10] MIPS: pm-cps: Add MIPSr6 CPU support

[Matt Redfearn]

This patch adds support for CPUs implementing the MIPSr6 ISA to the CPS
power management code. Three changes are necessary:

1. In MIPSr6, coupled coherence is necessary when CPUS implement multiple
   Virtual Processors (VPs).

2. MIPSr6 virtual processors are more like real cores and cannot yield
   to other VPs on the same core, so drop the MT ASE yield instruction.

3. To halt a MIPSr6 VP, the CPC VP_STOP register is used rather than the
   MT ASE TCHalt CP0 register.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/pm-cps.h |  6 ++++--
 arch/mips/kernel/pm-cps.c      | 22 ++++++++++++++++++----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/mips/include/asm/pm-cps.h b/arch/mips/include/asm/pm-cps.h
index 625eda53d571..89d58d80b77b 100644
--- a/arch/mips/include/asm/pm-cps.h
+++ b/arch/mips/include/asm/pm-cps.h
@@ -13,10 +13,12 @@
 
 /*
  * The CM & CPC can only handle coherence & power control on a per-core basis,
- * thus in an MT system the VPEs within each core are coupled and can only
+ * thus in an MT system the VP(E)s within each core are coupled and can only
  * enter or exit states requiring CM or CPC assistance in unison.
  */
-#ifdef CONFIG_MIPS_MT
+#if defined(CONFIG_CPU_MIPSR6)
+# define coupled_coherence cpu_has_vp
+#elif defined(CONFIG_MIPS_MT)
 # define coupled_coherence cpu_has_mipsmt
 #else
 # define coupled_coherence 0
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 572dc1d016a0..11c951f4f0b9 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -134,7 +134,7 @@ int cps_pm_enter_state(enum cps_pm_state state)
 		return -EINVAL;
 
 	/* Calculate which coupled CPUs (VPEs) are online */
-#ifdef CONFIG_MIPS_MT
+#if defined(CONFIG_MIPS_MT) || defined(CONFIG_CPU_MIPSR6)
 	if (cpu_online(cpu)) {
 		cpumask_and(coupled_mask, cpu_online_mask,
 			    &cpu_sibling_map[cpu]);
@@ -436,7 +436,8 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 			uasm_i_lw(&p, t0, 0, r_nc_count);
 			uasm_il_bltz(&p, &r, t0, lbl_secondary_cont);
 			uasm_i_ehb(&p);
-			uasm_i_yield(&p, zero, t1);
+			if (cpu_has_mipsmt)
+				uasm_i_yield(&p, zero, t1);
 			uasm_il_b(&p, &r, lbl_poll_cont);
 			uasm_i_nop(&p);
 		} else {
@@ -444,8 +445,21 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 			 * The core will lose power & this VPE will not continue
 			 * so it can simply halt here.
 			 */
-			uasm_i_addiu(&p, t0, zero, TCHALT_H);
-			uasm_i_mtc0(&p, t0, 2, 4);
+			if (cpu_has_mipsmt) {
+				/* Halt the VPE via C0 tchalt register */
+				uasm_i_addiu(&p, t0, zero, TCHALT_H);
+				uasm_i_mtc0(&p, t0, 2, 4);
+			} else if (cpu_has_vp) {
+				/* Halt the VP via the CPC VP_STOP register */
+				unsigned int vpe_id;
+
+				vpe_id = cpu_vpe_id(&cpu_data[cpu]);
+				uasm_i_addiu(&p, t0, zero, 1 << vpe_id);
+				UASM_i_LA(&p, t1, (long)addr_cpc_cl_vp_stop());
+				uasm_i_sw(&p, t0, 0, t1);
+			} else {
+				BUG();
+			}
 			uasm_build_label(&l, p, lbl_secondary_hang);
 			uasm_il_b(&p, &r, lbl_secondary_hang);
 			uasm_i_nop(&p);
-- 
2.7.4

[PATCH 08/10] MIPS: pm-cps: Support CM3 changes to Coherence Enable Register

[Matt Redfearn]

MIPS CM3 changed the management of coherence. Instead of a coherence
control register with a bitmask of coherent domains, CM3 simply has a
coherence enable register with a single bit to enable coherence of the
local core. Support this by clearing and setting this single bit to
disable / enable coherence.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/mips-cm.h |  1 +
 arch/mips/kernel/pm-cps.c       | 31 ++++++++++++++++++-------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 58e7874e9347..ac30981a8360 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -359,6 +359,7 @@ BUILD_CM_Cx_R_(tcid_8_priority,	0x80)
 /* GCR_Cx_COHERENCE register fields */
 #define CM_GCR_Cx_COHERENCE_COHDOMAINEN_SHF	0
 #define CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK	(_ULCAST_(0xff) << 0)
+#define CM3_GCR_Cx_COHERENCE_COHEN_MSK		(_ULCAST_(0x1) << 0)
 
 /* GCR_Cx_CONFIG register fields */
 #define CM_GCR_Cx_CONFIG_IOCUTYPE_SHF		10
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 11c951f4f0b9..9def81cd4f63 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -485,18 +485,20 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 	uasm_i_sync(&p, stype_memory);
 	uasm_i_ehb(&p);
 
-	/*
-	 * Disable all but self interventions. The load from COHCTL is defined
-	 * by the interAptiv & proAptiv SUMs as ensuring that the operation
-	 * resulting from the preceding store is complete.
-	 */
-	uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
-	uasm_i_sw(&p, t0, 0, r_pcohctl);
-	uasm_i_lw(&p, t0, 0, r_pcohctl);
-
-	/* Sync to ensure previous interventions are complete */
-	uasm_i_sync(&p, stype_intervention);
-	uasm_i_ehb(&p);
+	if (mips_cm_revision() < CM_REV_CM3) {
+		/*
+		* Disable all but self interventions. The load from COHCTL is
+		* defined by the interAptiv & proAptiv SUMs as ensuring that the
+		*  operation resulting from the preceding store is complete.
+		*/
+		uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
+		uasm_i_sw(&p, t0, 0, r_pcohctl);
+		uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+		/* Sync to ensure previous interventions are complete */
+		uasm_i_sync(&p, stype_intervention);
+		uasm_i_ehb(&p);
+	}
 
 	/* Disable coherence */
 	uasm_i_sw(&p, zero, 0, r_pcohctl);
@@ -571,7 +573,10 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 	 * will run this. The first will actually re-enable coherence & the
 	 * rest will just be performing a rather unusual nop.
 	 */
-	uasm_i_addiu(&p, t0, zero, CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK);
+	uasm_i_addiu(&p, t0, zero, mips_cm_revision() < CM_REV_CM3
+				? CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK
+				: CM3_GCR_Cx_COHERENCE_COHEN_MSK);
+
 	uasm_i_sw(&p, t0, 0, r_pcohctl);
 	uasm_i_lw(&p, t0, 0, r_pcohctl);
 
-- 
2.7.4

[PATCH 08/10] MIPS: pm-cps: Support CM3 changes to Coherence Enable Register

[Matt Redfearn]

MIPS CM3 changed the management of coherence. Instead of a coherence
control register with a bitmask of coherent domains, CM3 simply has a
coherence enable register with a single bit to enable coherence of the
local core. Support this by clearing and setting this single bit to
disable / enable coherence.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/mips-cm.h |  1 +
 arch/mips/kernel/pm-cps.c       | 31 ++++++++++++++++++-------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 58e7874e9347..ac30981a8360 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -359,6 +359,7 @@ BUILD_CM_Cx_R_(tcid_8_priority,	0x80)
 /* GCR_Cx_COHERENCE register fields */
 #define CM_GCR_Cx_COHERENCE_COHDOMAINEN_SHF	0
 #define CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK	(_ULCAST_(0xff) << 0)
+#define CM3_GCR_Cx_COHERENCE_COHEN_MSK		(_ULCAST_(0x1) << 0)
 
 /* GCR_Cx_CONFIG register fields */
 #define CM_GCR_Cx_CONFIG_IOCUTYPE_SHF		10
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 11c951f4f0b9..9def81cd4f63 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -485,18 +485,20 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 	uasm_i_sync(&p, stype_memory);
 	uasm_i_ehb(&p);
 
-	/*
-	 * Disable all but self interventions. The load from COHCTL is defined
-	 * by the interAptiv & proAptiv SUMs as ensuring that the operation
-	 * resulting from the preceding store is complete.
-	 */
-	uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
-	uasm_i_sw(&p, t0, 0, r_pcohctl);
-	uasm_i_lw(&p, t0, 0, r_pcohctl);
-
-	/* Sync to ensure previous interventions are complete */
-	uasm_i_sync(&p, stype_intervention);
-	uasm_i_ehb(&p);
+	if (mips_cm_revision() < CM_REV_CM3) {
+		/*
+		* Disable all but self interventions. The load from COHCTL is
+		* defined by the interAptiv & proAptiv SUMs as ensuring that the
+		*  operation resulting from the preceding store is complete.
+		*/
+		uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
+		uasm_i_sw(&p, t0, 0, r_pcohctl);
+		uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+		/* Sync to ensure previous interventions are complete */
+		uasm_i_sync(&p, stype_intervention);
+		uasm_i_ehb(&p);
+	}
 
 	/* Disable coherence */
 	uasm_i_sw(&p, zero, 0, r_pcohctl);
@@ -571,7 +573,10 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
 	 * will run this. The first will actually re-enable coherence & the
 	 * rest will just be performing a rather unusual nop.
 	 */
-	uasm_i_addiu(&p, t0, zero, CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK);
+	uasm_i_addiu(&p, t0, zero, mips_cm_revision() < CM_REV_CM3
+				? CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK
+				: CM3_GCR_Cx_COHERENCE_COHEN_MSK);
+
 	uasm_i_sw(&p, t0, 0, r_pcohctl);
 	uasm_i_lw(&p, t0, 0, r_pcohctl);
 
-- 
2.7.4

[PATCH 09/10] MIPS: SMP: Wrap call to mips_cpc_lock_other in mips_cm_lock_other

[Matt Redfearn]

All calls to mips_cpc_lock_other should be wrapped in
mips_cm_lock_other. This only matters if the system has CM3 and is using
cpu idle, since otherwise a) the CPC lock is sufficent for CM < 3 and b)
any systems with CM > 3 have not been able to use cpu idle until now.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/smp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index f95f094f36e4..78ccd5388654 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -192,9 +192,11 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
 				continue;
 
 			while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
+				mips_cm_lock_other(core, 0);
 				mips_cpc_lock_other(core);
 				write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
 				mips_cpc_unlock_other();
+				mips_cm_unlock_other();
 			}
 		}
 	}
-- 
2.7.4

[PATCH 09/10] MIPS: SMP: Wrap call to mips_cpc_lock_other in mips_cm_lock_other

[Matt Redfearn]

All calls to mips_cpc_lock_other should be wrapped in
mips_cm_lock_other. This only matters if the system has CM3 and is using
cpu idle, since otherwise a) the CPC lock is sufficent for CM < 3 and b)
any systems with CM > 3 have not been able to use cpu idle until now.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/kernel/smp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index f95f094f36e4..78ccd5388654 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -192,9 +192,11 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
 				continue;
 
 			while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
+				mips_cm_lock_other(core, 0);
 				mips_cpc_lock_other(core);
 				write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
 				mips_cpc_unlock_other();
+				mips_cm_unlock_other();
 			}
 		}
 	}
-- 
2.7.4

[PATCH 10/10] cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs.

[Matt Redfearn]

This patch enables the MIPS CPS driver for MIPSr6 CPUs.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>

---

 drivers/cpuidle/Kconfig.mips  | 2 +-
 drivers/cpuidle/cpuidle-cps.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/Kconfig.mips b/drivers/cpuidle/Kconfig.mips
index 4102be01d06a..512ee37b374b 100644
--- a/drivers/cpuidle/Kconfig.mips
+++ b/drivers/cpuidle/Kconfig.mips
@@ -5,7 +5,7 @@ config MIPS_CPS_CPUIDLE
 	bool "CPU Idle driver for MIPS CPS platforms"
 	depends on CPU_IDLE && MIPS_CPS
 	depends on SYS_SUPPORTS_MIPS_CPS
-	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT
+	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT || CPU_MIPSR6
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select MIPS_CPS_PM
 	default y
diff --git a/drivers/cpuidle/cpuidle-cps.c b/drivers/cpuidle/cpuidle-cps.c
index 1adb6980b707..926ba9871c62 100644
--- a/drivers/cpuidle/cpuidle-cps.c
+++ b/drivers/cpuidle/cpuidle-cps.c
@@ -163,7 +163,7 @@ static int __init cps_cpuidle_init(void)
 		core = cpu_data[cpu].core;
 		device = &per_cpu(cpuidle_dev, cpu);
 		device->cpu = cpu;
-#ifdef CONFIG_MIPS_MT
+#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 		cpumask_copy(&device->coupled_cpus, &cpu_sibling_map[cpu]);
 #endif
 
-- 
2.7.4

[PATCH 10/10] cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs.

[Matt Redfearn]

This patch enables the MIPS CPS driver for MIPSr6 CPUs.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>

---

 drivers/cpuidle/Kconfig.mips  | 2 +-
 drivers/cpuidle/cpuidle-cps.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/Kconfig.mips b/drivers/cpuidle/Kconfig.mips
index 4102be01d06a..512ee37b374b 100644
--- a/drivers/cpuidle/Kconfig.mips
+++ b/drivers/cpuidle/Kconfig.mips
@@ -5,7 +5,7 @@ config MIPS_CPS_CPUIDLE
 	bool "CPU Idle driver for MIPS CPS platforms"
 	depends on CPU_IDLE && MIPS_CPS
 	depends on SYS_SUPPORTS_MIPS_CPS
-	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT
+	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT || CPU_MIPSR6
 	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
 	select MIPS_CPS_PM
 	default y
diff --git a/drivers/cpuidle/cpuidle-cps.c b/drivers/cpuidle/cpuidle-cps.c
index 1adb6980b707..926ba9871c62 100644
--- a/drivers/cpuidle/cpuidle-cps.c
+++ b/drivers/cpuidle/cpuidle-cps.c
@@ -163,7 +163,7 @@ static int __init cps_cpuidle_init(void)
 		core = cpu_data[cpu].core;
 		device = &per_cpu(cpuidle_dev, cpu);
 		device->cpu = cpu;
-#ifdef CONFIG_MIPS_MT
+#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 		cpumask_copy(&device->coupled_cpus, &cpu_sibling_map[cpu]);
 #endif
 
-- 
2.7.4

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Peter Zijlstra]

On Wed, Aug 31, 2016 at 11:44:35AM +0100, Matt Redfearn wrote:
> Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but
> architecturally defined ordering barrier. If a CPU does not implement it,
> the arch specifies that it must fall back to SYNC(0).
> 
> Define the barrier type and always use it in the pm-cps code rather than
> falling back to the heavyweight sync(0) such that we can benefit from
> the lighter weight sync.
> 

Changelog does not explain what 0x10 is, nor why its sufficient for this
case.

Changelog also fails to explain why you do this.

How do you expect anybody to review this?

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

On 31/08/16 12:48, Peter Zijlstra wrote:
> On Wed, Aug 31, 2016 at 11:44:35AM +0100, Matt Redfearn wrote:
>> Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but
>> architecturally defined ordering barrier. If a CPU does not implement it,
>> the arch specifies that it must fall back to SYNC(0).
>>
>> Define the barrier type and always use it in the pm-cps code rather than
>> falling back to the heavyweight sync(0) such that we can benefit from
>> the lighter weight sync.
>>
> Changelog does not explain what 0x10 is, nor why its sufficient for this
> case.

Hi Peter,

The code previously had 0x10 as a magic number, this patch just replaces 
that with a #defined name. The value is documented in the MIPS64 
instruction set manual, https://imgtec.com/?do-download=4302, table 6.5.

This sync type has been standard since MIPSr2. That document also states 
that "If an implementation does not use one of these non-zero values to 
define a different synchronization behavior, then that non-zero value of 
stype must act the same as stype zero completion barrier." As such, 
stype_ordering can always be set to this sync type rather than setting 
it only for certain CPUs.

Thanks,
Matt

>
> Changelog also fails to explain why you do this.
> How do you expect anybody to review this?

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

On 31/08/16 12:48, Peter Zijlstra wrote:
> On Wed, Aug 31, 2016 at 11:44:35AM +0100, Matt Redfearn wrote:
>> Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but
>> architecturally defined ordering barrier. If a CPU does not implement it,
>> the arch specifies that it must fall back to SYNC(0).
>>
>> Define the barrier type and always use it in the pm-cps code rather than
>> falling back to the heavyweight sync(0) such that we can benefit from
>> the lighter weight sync.
>>
> Changelog does not explain what 0x10 is, nor why its sufficient for this
> case.

Hi Peter,

The code previously had 0x10 as a magic number, this patch just replaces 
that with a #defined name. The value is documented in the MIPS64 
instruction set manual, https://imgtec.com/?do-download=4302, table 6.5.

This sync type has been standard since MIPSr2. That document also states 
that "If an implementation does not use one of these non-zero values to 
define a different synchronization behavior, then that non-zero value of 
stype must act the same as stype zero completion barrier." As such, 
stype_ordering can always be set to this sync type rather than setting 
it only for certain CPUs.

Thanks,
Matt

>
> Changelog also fails to explain why you do this.
> How do you expect anybody to review this?

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Peter Zijlstra]

On Wed, Aug 31, 2016 at 02:36:26PM +0100, Matt Redfearn wrote:
> 
> The code previously had 0x10 as a magic number, this patch just replaces
> that with a #defined name. The value is documented in the MIPS64 instruction
> set manual, https://imgtec.com/?do-download=4302, table 6.5.
> 
> This sync type has been standard since MIPSr2. That document also states
> that "If an implementation does not use one of these non-zero values to
> define a different synchronization behavior, then that non-zero value of
> stype must act the same as stype zero completion barrier." As such,
> stype_ordering can always be set to this sync type rather than setting it
> only for certain CPUs.

Right. We all had a bunch of fun trying to decode that manual a while
back, and IIRC were left with a bunch of questions on what it all meant
in 3+ CPU scenarios.

In anycase, not sure why I was Cc'ed to this patch, but in general I
have low confidence in barrier patches that lack lots of detail. And the
code in question has woefully inadequate comments:

                /* Ordering barrier */
                uasm_i_sync(&p, stype_ordering);

Order what against what and why? Is my first question. A comment really
should explain.

In any case, you've removed the only (runtime) assignment to the
variable, it can become 'const'.

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

On 31/08/16 15:28, Peter Zijlstra wrote:
> On Wed, Aug 31, 2016 at 02:36:26PM +0100, Matt Redfearn wrote:
>> The code previously had 0x10 as a magic number, this patch just replaces
>> that with a #defined name. The value is documented in the MIPS64 instruction
>> set manual, https://imgtec.com/?do-download=4302, table 6.5.
>>
>> This sync type has been standard since MIPSr2. That document also states
>> that "If an implementation does not use one of these non-zero values to
>> define a different synchronization behavior, then that non-zero value of
>> stype must act the same as stype zero completion barrier." As such,
>> stype_ordering can always be set to this sync type rather than setting it
>> only for certain CPUs.

Hi Peter,

> Right. We all had a bunch of fun trying to decode that manual a while
> back, and IIRC were left with a bunch of questions on what it all meant
> in 3+ CPU scenarios.

Yes, I remember that fun....

>
> In anycase, not sure why I was Cc'ed to this patch, but in general I

Patman decided to CC you as you've touched arch/mips/include/barrier.h I 
suppose.

> have low confidence in barrier patches that lack lots of detail. And the
> code in question has woefully inadequate comments:
>
>                  /* Ordering barrier */
>                  uasm_i_sync(&p, stype_ordering);
>
> Order what against what and why? Is my first question. A comment really
> should explain.

Fair enough - we'll put something together to improve the comments.

>
> In any case, you've removed the only (runtime) assignment to the
> variable, it can become 'const'.

True enough.

Thanks,
Matt

Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier

[Matt Redfearn]

On 31/08/16 15:28, Peter Zijlstra wrote:
> On Wed, Aug 31, 2016 at 02:36:26PM +0100, Matt Redfearn wrote:
>> The code previously had 0x10 as a magic number, this patch just replaces
>> that with a #defined name. The value is documented in the MIPS64 instruction
>> set manual, https://imgtec.com/?do-download=4302, table 6.5.
>>
>> This sync type has been standard since MIPSr2. That document also states
>> that "If an implementation does not use one of these non-zero values to
>> define a different synchronization behavior, then that non-zero value of
>> stype must act the same as stype zero completion barrier." As such,
>> stype_ordering can always be set to this sync type rather than setting it
>> only for certain CPUs.

Hi Peter,

> Right. We all had a bunch of fun trying to decode that manual a while
> back, and IIRC were left with a bunch of questions on what it all meant
> in 3+ CPU scenarios.

Yes, I remember that fun....

>
> In anycase, not sure why I was Cc'ed to this patch, but in general I

Patman decided to CC you as you've touched arch/mips/include/barrier.h I 
suppose.

> have low confidence in barrier patches that lack lots of detail. And the
> code in question has woefully inadequate comments:
>
>                  /* Ordering barrier */
>                  uasm_i_sync(&p, stype_ordering);
>
> Order what against what and why? Is my first question. A comment really
> should explain.

Fair enough - we'll put something together to improve the comments.

>
> In any case, you've removed the only (runtime) assignment to the
> variable, it can become 'const'.

True enough.

Thanks,
Matt