[PATCH v5 4/6] pv-qspinlock: powerpc support pv-qspinlock

[Pan Xinhui]

As we need let pv-qspinlock-kernel run on all environment which might
have no powervm, we should runtime choose which qspinlock version to
use.

The default pv-qspinlock use native version. pv_lock initialization
should be done in bootstage with irq disabled. And if there is PHYP,
restore pv_lock_ops callbacks to pv version.

There is also a hash table, we store cpu number into it and the key is
lock. So everytime pv_wait can know who is the lock holder by searching
the lock. Also store the lock in a per_cpu struct, and remove it when we
own the lock. pv_wait need know which lock we are spinning on.

Signed-off-by: Pan Xinhui 
---
 arch/powerpc/include/asm/qspinlock.h   |  15 +++
 arch/powerpc/include/asm/qspinlock_paravirt.h  |  38 +++
 .../powerpc/include/asm/qspinlock_paravirt_types.h |  13 +++
 arch/powerpc/kernel/paravirt.c | 121 +
 arch/powerpc/platforms/pseries/setup.c |   5 +
 5 files changed, 192 insertions(+)
 create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt.h
 create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt_types.h
 create mode 100644 arch/powerpc/kernel/paravirt.c

diff --git a/arch/powerpc/include/asm/qspinlock.h 
b/arch/powerpc/include/asm/qspinlock.h
index fc83cd2..61a0d00 100644
--- a/arch/powerpc/include/asm/qspinlock.h
+++ b/arch/powerpc/include/asm/qspinlock.h
@@ -16,10 +16,25 @@ static inline void native_queued_spin_unlock(struct 
qspinlock *lock)
smp_store_release(locked, 0);
 }
 
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+
+#include 
+
+static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+{
+   pv_queued_spin_lock(lock, val);
+}
+
+static inline void queued_spin_unlock(struct qspinlock *lock)
+{
+   pv_queued_spin_unlock(lock);
+}
+#else
 static inline void queued_spin_unlock(struct qspinlock *lock)
 {
native_queued_spin_unlock(lock);
 }
+#endif
 
 #include 
 
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt.h 
b/arch/powerpc/include/asm/qspinlock_paravirt.h
new file mode 100644
index 000..cd17a79
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt.h
@@ -0,0 +1,38 @@
+#ifndef CONFIG_PARAVIRT_SPINLOCKS
+#error "do not include this file"
+#endif
+
+#ifndef _ASM_QSPINLOCK_PARAVIRT_H
+#define _ASM_QSPINLOCK_PARAVIRT_H
+
+#include  
+
+extern void pv_lock_init(void);
+extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_init_lock_hash(void);
+extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_queued_spin_unlock(struct qspinlock *lock);
+
+static inline void pv_queued_spin_lock(struct qspinlock *lock, u32 val)
+{
+   CLEAR_IO_SYNC;
+   pv_lock_op.lock(lock, val);
+}
+
+static inline void pv_queued_spin_unlock(struct qspinlock *lock)
+{
+   SYNC_IO;
+   pv_lock_op.unlock(lock);
+}
+
+static inline void pv_wait(u8 *ptr, u8 val, int lockcpu)
+{
+   pv_lock_op.wait(ptr, val, lockcpu);
+}
+
+static inline void pv_kick(int cpu)
+{
+   pv_lock_op.kick(cpu);
+}
+
+#endif
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt_types.h 
b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
new file mode 100644
index 000..e1fdeb0
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
@@ -0,0 +1,13 @@
+#ifndef _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+#define _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+
+struct pv_lock_ops {
+   void (*lock)(struct qspinlock *lock, u32 val);
+   void (*unlock)(struct qspinlock *lock);
+   void (*wait)(u8 *ptr, u8 val, int cpu);
+   void (*kick)(int cpu);
+};
+
+extern struct pv_lock_ops pv_lock_op;
+
+#endif
diff --git a/arch/powerpc/kernel/paravirt.c b/arch/powerpc/kernel/paravirt.c
new file mode 100644
index 000..2e87fa6
--- /dev/null
+++ b/arch/powerpc/kernel/paravirt.c
@@ -0,0 +1,121 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include 
+#include 
+#include 
+#include 
+
+#define NUM_LOCK_CPU_ENTRY_SHIFT 16
+#define NUM_LOCK_CPU_ENTRY (1 << NUM_LOCK_CPU_ENTRY_SHIFT)
+#define NUM_LOCKS_PER_CPU 4
+
+static u16 *hash_lock_cpu_ptr;
+
+struct locks_on_cpu {
+   void *l[NUM_LOCKS_PER_CPU];
+   int count;
+};
+
+static DEFINE_PER_CPU(struct locks_on_cpu, node);
+
+static u16 *hash(void *l)
+{
+   int val = hash_ptr(l, NUM_LOCK_CPU_ENTRY_SHIFT);
+
+   return _lock_cpu_ptr[val];
+}
+
+static void __init init_hash(void)
+{
+   int size = NUM_LOCK_CPU_ENTRY * sizeof(*hash_lock_cpu_ptr);
+
+   hash_lock_cpu_ptr = memblock_virt_alloc(size, 0);
+   memset(hash_lock_cpu_ptr, 0, size);
+}
+
+#define lock_get_holder(l) \
+   ((int)*hash(l) - 1)
+
+#define lock_set_holder(l) \
+ 

[PATCH v5 4/6] pv-qspinlock: powerpc support pv-qspinlock

[Pan Xinhui]

As we need let pv-qspinlock-kernel run on all environment which might
have no powervm, we should runtime choose which qspinlock version to
use.

The default pv-qspinlock use native version. pv_lock initialization
should be done in bootstage with irq disabled. And if there is PHYP,
restore pv_lock_ops callbacks to pv version.

There is also a hash table, we store cpu number into it and the key is
lock. So everytime pv_wait can know who is the lock holder by searching
the lock. Also store the lock in a per_cpu struct, and remove it when we
own the lock. pv_wait need know which lock we are spinning on.

Signed-off-by: Pan Xinhui 
---
 arch/powerpc/include/asm/qspinlock.h   |  15 +++
 arch/powerpc/include/asm/qspinlock_paravirt.h  |  38 +++
 .../powerpc/include/asm/qspinlock_paravirt_types.h |  13 +++
 arch/powerpc/kernel/paravirt.c | 121 +
 arch/powerpc/platforms/pseries/setup.c |   5 +
 5 files changed, 192 insertions(+)
 create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt.h
 create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt_types.h
 create mode 100644 arch/powerpc/kernel/paravirt.c

diff --git a/arch/powerpc/include/asm/qspinlock.h 
b/arch/powerpc/include/asm/qspinlock.h
index fc83cd2..61a0d00 100644
--- a/arch/powerpc/include/asm/qspinlock.h
+++ b/arch/powerpc/include/asm/qspinlock.h
@@ -16,10 +16,25 @@ static inline void native_queued_spin_unlock(struct 
qspinlock *lock)
smp_store_release(locked, 0);
 }
 
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+
+#include 
+
+static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+{
+   pv_queued_spin_lock(lock, val);
+}
+
+static inline void queued_spin_unlock(struct qspinlock *lock)
+{
+   pv_queued_spin_unlock(lock);
+}
+#else
 static inline void queued_spin_unlock(struct qspinlock *lock)
 {
native_queued_spin_unlock(lock);
 }
+#endif
 
 #include 
 
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt.h 
b/arch/powerpc/include/asm/qspinlock_paravirt.h
new file mode 100644
index 000..cd17a79
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt.h
@@ -0,0 +1,38 @@
+#ifndef CONFIG_PARAVIRT_SPINLOCKS
+#error "do not include this file"
+#endif
+
+#ifndef _ASM_QSPINLOCK_PARAVIRT_H
+#define _ASM_QSPINLOCK_PARAVIRT_H
+
+#include  
+
+extern void pv_lock_init(void);
+extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_init_lock_hash(void);
+extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_queued_spin_unlock(struct qspinlock *lock);
+
+static inline void pv_queued_spin_lock(struct qspinlock *lock, u32 val)
+{
+   CLEAR_IO_SYNC;
+   pv_lock_op.lock(lock, val);
+}
+
+static inline void pv_queued_spin_unlock(struct qspinlock *lock)
+{
+   SYNC_IO;
+   pv_lock_op.unlock(lock);
+}
+
+static inline void pv_wait(u8 *ptr, u8 val, int lockcpu)
+{
+   pv_lock_op.wait(ptr, val, lockcpu);
+}
+
+static inline void pv_kick(int cpu)
+{
+   pv_lock_op.kick(cpu);
+}
+
+#endif
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt_types.h 
b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
new file mode 100644
index 000..e1fdeb0
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
@@ -0,0 +1,13 @@
+#ifndef _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+#define _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+
+struct pv_lock_ops {
+   void (*lock)(struct qspinlock *lock, u32 val);
+   void (*unlock)(struct qspinlock *lock);
+   void (*wait)(u8 *ptr, u8 val, int cpu);
+   void (*kick)(int cpu);
+};
+
+extern struct pv_lock_ops pv_lock_op;
+
+#endif
diff --git a/arch/powerpc/kernel/paravirt.c b/arch/powerpc/kernel/paravirt.c
new file mode 100644
index 000..2e87fa6
--- /dev/null
+++ b/arch/powerpc/kernel/paravirt.c
@@ -0,0 +1,121 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include 
+#include 
+#include 
+#include 
+
+#define NUM_LOCK_CPU_ENTRY_SHIFT 16
+#define NUM_LOCK_CPU_ENTRY (1 << NUM_LOCK_CPU_ENTRY_SHIFT)
+#define NUM_LOCKS_PER_CPU 4
+
+static u16 *hash_lock_cpu_ptr;
+
+struct locks_on_cpu {
+   void *l[NUM_LOCKS_PER_CPU];
+   int count;
+};
+
+static DEFINE_PER_CPU(struct locks_on_cpu, node);
+
+static u16 *hash(void *l)
+{
+   int val = hash_ptr(l, NUM_LOCK_CPU_ENTRY_SHIFT);
+
+   return _lock_cpu_ptr[val];
+}
+
+static void __init init_hash(void)
+{
+   int size = NUM_LOCK_CPU_ENTRY * sizeof(*hash_lock_cpu_ptr);
+
+   hash_lock_cpu_ptr = memblock_virt_alloc(size, 0);
+   memset(hash_lock_cpu_ptr, 0, size);
+}
+
+#define lock_get_holder(l) \
+   ((int)*hash(l) - 1)
+
+#define lock_set_holder(l) \
+