diff mbox series

[V11,01/17] asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock

Message ID 20230910082911.3378782-2-guoren@kernel.org (mailing list archive)
State Changes Requested
Headers show
Series riscv: Add Native/Paravirt qspinlock support | expand

Checks

Context Check Description
conchuod/tree_selection fail Failed to apply to next/pending-fixes, riscv/for-next or riscv/master

Commit Message

Guo Ren Sept. 10, 2023, 8:28 a.m. UTC
From: Guo Ren <guoren@linux.alibaba.com>

The arch_spinlock_t of qspinlock has contained the atomic_t val, which
satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
into qspinlock_types.h. This is the preparation for the next combo
spinlock.

Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
 include/asm-generic/spinlock.h       | 14 +++++++-------
 include/asm-generic/spinlock_types.h | 12 ++----------
 2 files changed, 9 insertions(+), 17 deletions(-)

Comments

Leonardo Bras Sept. 11, 2023, 7:05 p.m. UTC | #1
On Sun, 2023-09-10 at 04:28 -0400, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> The arch_spinlock_t of qspinlock has contained the atomic_t val, which
> satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
> into qspinlock_types.h. This is the preparation for the next combo
> spinlock.
> 
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> ---
>  include/asm-generic/spinlock.h       | 14 +++++++-------
>  include/asm-generic/spinlock_types.h | 12 ++----------
>  2 files changed, 9 insertions(+), 17 deletions(-)
> 
> diff --git a/include/asm-generic/spinlock.h b/include/asm-generic/spinlock.h
> index 90803a826ba0..4773334ee638 100644
> --- a/include/asm-generic/spinlock.h
> +++ b/include/asm-generic/spinlock.h
> @@ -32,7 +32,7 @@
>  
>  static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
>  {
> -	u32 val = atomic_fetch_add(1<<16, lock);
> +	u32 val = atomic_fetch_add(1<<16, &lock->val);
>  	u16 ticket = val >> 16;
>  
>  	if (ticket == (u16)val)
> @@ -46,31 +46,31 @@ static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
>  	 * have no outstanding writes due to the atomic_fetch_add() the extra
>  	 * orderings are free.
>  	 */
> -	atomic_cond_read_acquire(lock, ticket == (u16)VAL);
> +	atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
>  	smp_mb();
>  }
>  
>  static __always_inline bool arch_spin_trylock(arch_spinlock_t *lock)
>  {
> -	u32 old = atomic_read(lock);
> +	u32 old = atomic_read(&lock->val);
>  
>  	if ((old >> 16) != (old & 0xffff))
>  		return false;
>  
> -	return atomic_try_cmpxchg(lock, &old, old + (1<<16)); /* SC, for RCsc */
> +	return atomic_try_cmpxchg(&lock->val, &old, old + (1<<16)); /* SC, for RCsc */
>  }
>  
>  static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)
>  {
>  	u16 *ptr = (u16 *)lock + IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> -	u32 val = atomic_read(lock);
> +	u32 val = atomic_read(&lock->val);
>  
>  	smp_store_release(ptr, (u16)val + 1);
>  }
>  
>  static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
>  {
> -	u32 val = lock.counter;
> +	u32 val = lock.val.counter;
>  
>  	return ((val >> 16) == (val & 0xffff));
>  }

This one seems to be different in torvalds/master, but I suppose it's because of
the requirement patches I have not merged.

> @@ -84,7 +84,7 @@ static __always_inline int arch_spin_is_locked(arch_spinlock_t *lock)
>  
>  static __always_inline int arch_spin_is_contended(arch_spinlock_t *lock)
>  {
> -	u32 val = atomic_read(lock);
> +	u32 val = atomic_read(&lock->val);
>  
>  	return (s16)((val >> 16) - (val & 0xffff)) > 1;
>  }
> diff --git a/include/asm-generic/spinlock_types.h b/include/asm-generic/spinlock_types.h
> index 8962bb730945..f534aa5de394 100644
> --- a/include/asm-generic/spinlock_types.h
> +++ b/include/asm-generic/spinlock_types.h
> @@ -3,15 +3,7 @@
>  #ifndef __ASM_GENERIC_SPINLOCK_TYPES_H
>  #define __ASM_GENERIC_SPINLOCK_TYPES_H
>  
> -#include <linux/types.h>
> -typedef atomic_t arch_spinlock_t;
> -
> -/*
> - * qrwlock_types depends on arch_spinlock_t, so we must typedef that before the
> - * include.
> - */
> -#include <asm/qrwlock_types.h>
> -
> -#define __ARCH_SPIN_LOCK_UNLOCKED	ATOMIC_INIT(0)
> +#include <asm-generic/qspinlock_types.h>
> +#include <asm-generic/qrwlock_types.h>
>  
>  #endif /* __ASM_GENERIC_SPINLOCK_TYPES_H */

FWIW, LGTM:

Reviewed-by: Leonardo Bras <leobras@redhat.com>


Just a suggestion: In this patch I could see a lot of usage changes to
arch_spinlock_t, and only at the end I could see the actual change in the .h
file.

In cases like this, it looks nicer to see the .h file first.

I recently found out about this git diff.orderFile option, which helps to
achieve exactly this.

I use the following git.orderfile, adapted from qemu:

############################################################################
#
# order file for git, to produce patches which are easier to review
# by diffing the important stuff like interface changes first.
#
# one-off usage:
#   git diff -O scripts/git.orderfile ...
#
# add to git config:
#   git config diff.orderFile scripts/git.orderfile
#

MAINTAINERS

# Documentation
Documentation/*
*.rst
*.rst.inc

# build system
Kbuild
Makefile*
*.mak

# semantic patches
*.cocci

# headers
*.h
*.h.inc

# code
*.c
*.c.inc
Guo Ren Sept. 13, 2023, 1:55 a.m. UTC | #2
On Tue, Sep 12, 2023 at 3:05 AM Leonardo Brás <leobras@redhat.com> wrote:
>
> On Sun, 2023-09-10 at 04:28 -0400, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > The arch_spinlock_t of qspinlock has contained the atomic_t val, which
> > satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
> > into qspinlock_types.h. This is the preparation for the next combo
> > spinlock.
> >
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > ---
> >  include/asm-generic/spinlock.h       | 14 +++++++-------
> >  include/asm-generic/spinlock_types.h | 12 ++----------
> >  2 files changed, 9 insertions(+), 17 deletions(-)
> >
> > diff --git a/include/asm-generic/spinlock.h b/include/asm-generic/spinlock.h
> > index 90803a826ba0..4773334ee638 100644
> > --- a/include/asm-generic/spinlock.h
> > +++ b/include/asm-generic/spinlock.h
> > @@ -32,7 +32,7 @@
> >
> >  static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
> >  {
> > -     u32 val = atomic_fetch_add(1<<16, lock);
> > +     u32 val = atomic_fetch_add(1<<16, &lock->val);
> >       u16 ticket = val >> 16;
> >
> >       if (ticket == (u16)val)
> > @@ -46,31 +46,31 @@ static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
> >        * have no outstanding writes due to the atomic_fetch_add() the extra
> >        * orderings are free.
> >        */
> > -     atomic_cond_read_acquire(lock, ticket == (u16)VAL);
> > +     atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
> >       smp_mb();
> >  }
> >
> >  static __always_inline bool arch_spin_trylock(arch_spinlock_t *lock)
> >  {
> > -     u32 old = atomic_read(lock);
> > +     u32 old = atomic_read(&lock->val);
> >
> >       if ((old >> 16) != (old & 0xffff))
> >               return false;
> >
> > -     return atomic_try_cmpxchg(lock, &old, old + (1<<16)); /* SC, for RCsc */
> > +     return atomic_try_cmpxchg(&lock->val, &old, old + (1<<16)); /* SC, for RCsc */
> >  }
> >
> >  static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)
> >  {
> >       u16 *ptr = (u16 *)lock + IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> > -     u32 val = atomic_read(lock);
> > +     u32 val = atomic_read(&lock->val);
> >
> >       smp_store_release(ptr, (u16)val + 1);
> >  }
> >
> >  static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
> >  {
> > -     u32 val = lock.counter;
> > +     u32 val = lock.val.counter;
> >
> >       return ((val >> 16) == (val & 0xffff));
> >  }
>
> This one seems to be different in torvalds/master, but I suppose it's because of
> the requirement patches I have not merged.
>
> > @@ -84,7 +84,7 @@ static __always_inline int arch_spin_is_locked(arch_spinlock_t *lock)
> >
> >  static __always_inline int arch_spin_is_contended(arch_spinlock_t *lock)
> >  {
> > -     u32 val = atomic_read(lock);
> > +     u32 val = atomic_read(&lock->val);
> >
> >       return (s16)((val >> 16) - (val & 0xffff)) > 1;
> >  }
> > diff --git a/include/asm-generic/spinlock_types.h b/include/asm-generic/spinlock_types.h
> > index 8962bb730945..f534aa5de394 100644
> > --- a/include/asm-generic/spinlock_types.h
> > +++ b/include/asm-generic/spinlock_types.h
> > @@ -3,15 +3,7 @@
> >  #ifndef __ASM_GENERIC_SPINLOCK_TYPES_H
> >  #define __ASM_GENERIC_SPINLOCK_TYPES_H
> >
> > -#include <linux/types.h>
> > -typedef atomic_t arch_spinlock_t;
> > -
> > -/*
> > - * qrwlock_types depends on arch_spinlock_t, so we must typedef that before the
> > - * include.
> > - */
> > -#include <asm/qrwlock_types.h>
> > -
> > -#define __ARCH_SPIN_LOCK_UNLOCKED    ATOMIC_INIT(0)
> > +#include <asm-generic/qspinlock_types.h>
> > +#include <asm-generic/qrwlock_types.h>
> >
> >  #endif /* __ASM_GENERIC_SPINLOCK_TYPES_H */
>
> FWIW, LGTM:
>
> Reviewed-by: Leonardo Bras <leobras@redhat.com>
>
>
> Just a suggestion: In this patch I could see a lot of usage changes to
> arch_spinlock_t, and only at the end I could see the actual change in the .h
> file.
 include/asm-generic/spinlock.h       | 14 +++++++-------
 include/asm-generic/spinlock_types.h | 12 ++----------

All are .h files. So, how to use git.orderfile?

>
> In cases like this, it looks nicer to see the .h file first.
>
> I recently found out about this git diff.orderFile option, which helps to
> achieve exactly this.
>
> I use the following git.orderfile, adapted from qemu:
>
> ############################################################################
> #
> # order file for git, to produce patches which are easier to review
> # by diffing the important stuff like interface changes first.
> #
> # one-off usage:
> #   git diff -O scripts/git.orderfile ...
> #
> # add to git config:
> #   git config diff.orderFile scripts/git.orderfile
> #
>
> MAINTAINERS
>
> # Documentation
> Documentation/*
> *.rst
> *.rst.inc
>
> # build system
> Kbuild
> Makefile*
> *.mak
>
> # semantic patches
> *.cocci
>
> # headers
> *.h
> *.h.inc
>
> # code
> *.c
> *.c.inc
>
>
Leonardo Bras Sept. 13, 2023, 7:59 a.m. UTC | #3
On Wed, Sep 13, 2023 at 09:55:31AM +0800, Guo Ren wrote:
> On Tue, Sep 12, 2023 at 3:05 AM Leonardo Brás <leobras@redhat.com> wrote:
> >
> > On Sun, 2023-09-10 at 04:28 -0400, guoren@kernel.org wrote:
> > > From: Guo Ren <guoren@linux.alibaba.com>
> > >
> > > The arch_spinlock_t of qspinlock has contained the atomic_t val, which
> > > satisfies the ticket-lock requirement. Thus, unify the arch_spinlock_t
> > > into qspinlock_types.h. This is the preparation for the next combo
> > > spinlock.
> > >
> > > Signed-off-by: Guo Ren <guoren@kernel.org>
> > > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > > ---
> > >  include/asm-generic/spinlock.h       | 14 +++++++-------
> > >  include/asm-generic/spinlock_types.h | 12 ++----------
> > >  2 files changed, 9 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/include/asm-generic/spinlock.h b/include/asm-generic/spinlock.h
> > > index 90803a826ba0..4773334ee638 100644
> > > --- a/include/asm-generic/spinlock.h
> > > +++ b/include/asm-generic/spinlock.h
> > > @@ -32,7 +32,7 @@
> > >
> > >  static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
> > >  {
> > > -     u32 val = atomic_fetch_add(1<<16, lock);
> > > +     u32 val = atomic_fetch_add(1<<16, &lock->val);
> > >       u16 ticket = val >> 16;
> > >
> > >       if (ticket == (u16)val)
> > > @@ -46,31 +46,31 @@ static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
> > >        * have no outstanding writes due to the atomic_fetch_add() the extra
> > >        * orderings are free.
> > >        */
> > > -     atomic_cond_read_acquire(lock, ticket == (u16)VAL);
> > > +     atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
> > >       smp_mb();
> > >  }
> > >
> > >  static __always_inline bool arch_spin_trylock(arch_spinlock_t *lock)
> > >  {
> > > -     u32 old = atomic_read(lock);
> > > +     u32 old = atomic_read(&lock->val);
> > >
> > >       if ((old >> 16) != (old & 0xffff))
> > >               return false;
> > >
> > > -     return atomic_try_cmpxchg(lock, &old, old + (1<<16)); /* SC, for RCsc */
> > > +     return atomic_try_cmpxchg(&lock->val, &old, old + (1<<16)); /* SC, for RCsc */
> > >  }
> > >
> > >  static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)
> > >  {
> > >       u16 *ptr = (u16 *)lock + IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> > > -     u32 val = atomic_read(lock);
> > > +     u32 val = atomic_read(&lock->val);
> > >
> > >       smp_store_release(ptr, (u16)val + 1);
> > >  }
> > >
> > >  static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
> > >  {
> > > -     u32 val = lock.counter;
> > > +     u32 val = lock.val.counter;
> > >
> > >       return ((val >> 16) == (val & 0xffff));
> > >  }
> >
> > This one seems to be different in torvalds/master, but I suppose it's because of
> > the requirement patches I have not merged.
> >
> > > @@ -84,7 +84,7 @@ static __always_inline int arch_spin_is_locked(arch_spinlock_t *lock)
> > >
> > >  static __always_inline int arch_spin_is_contended(arch_spinlock_t *lock)
> > >  {
> > > -     u32 val = atomic_read(lock);
> > > +     u32 val = atomic_read(&lock->val);
> > >
> > >       return (s16)((val >> 16) - (val & 0xffff)) > 1;
> > >  }
> > > diff --git a/include/asm-generic/spinlock_types.h b/include/asm-generic/spinlock_types.h
> > > index 8962bb730945..f534aa5de394 100644
> > > --- a/include/asm-generic/spinlock_types.h
> > > +++ b/include/asm-generic/spinlock_types.h
> > > @@ -3,15 +3,7 @@
> > >  #ifndef __ASM_GENERIC_SPINLOCK_TYPES_H
> > >  #define __ASM_GENERIC_SPINLOCK_TYPES_H
> > >
> > > -#include <linux/types.h>
> > > -typedef atomic_t arch_spinlock_t;
> > > -
> > > -/*
> > > - * qrwlock_types depends on arch_spinlock_t, so we must typedef that before the
> > > - * include.
> > > - */
> > > -#include <asm/qrwlock_types.h>
> > > -
> > > -#define __ARCH_SPIN_LOCK_UNLOCKED    ATOMIC_INIT(0)
> > > +#include <asm-generic/qspinlock_types.h>
> > > +#include <asm-generic/qrwlock_types.h>
> > >
> > >  #endif /* __ASM_GENERIC_SPINLOCK_TYPES_H */
> >
> > FWIW, LGTM:
> >
> > Reviewed-by: Leonardo Bras <leobras@redhat.com>
> >
> >
> > Just a suggestion: In this patch I could see a lot of usage changes to
> > arch_spinlock_t, and only at the end I could see the actual change in the .h
> > file.
>  include/asm-generic/spinlock.h       | 14 +++++++-------
>  include/asm-generic/spinlock_types.h | 12 ++----------
> 
> All are .h files. So, how to use git.orderfile?

Yeap, you are right.

For some reason I got confused about seeing functions before type definition.

But in any way, we can get the same result with:

*types.h
*.h
*.c

Meaning 'spinlock_types.h' will appear before 'spinlock.h'.

After first suggesting this, I also sent a patch providing a default
orderFile for the kernel, and I also added this to the latest version:

https://lore.kernel.org/all/20230913075550.90934-2-leobras@redhat.com/

> 
> >
> > In cases like this, it looks nicer to see the .h file first.
> >
> > I recently found out about this git diff.orderFile option, which helps to
> > achieve exactly this.
> >
> > I use the following git.orderfile, adapted from qemu:
> >
> > ############################################################################
> > #
> > # order file for git, to produce patches which are easier to review
> > # by diffing the important stuff like interface changes first.
> > #
> > # one-off usage:
> > #   git diff -O scripts/git.orderfile ...
> > #
> > # add to git config:
> > #   git config diff.orderFile scripts/git.orderfile
> > #
> >
> > MAINTAINERS
> >
> > # Documentation
> > Documentation/*
> > *.rst
> > *.rst.inc
> >
> > # build system
> > Kbuild
> > Makefile*
> > *.mak
> >
> > # semantic patches
> > *.cocci
> >
> > # headers
> > *.h
> > *.h.inc
> >
> > # code
> > *.c
> > *.c.inc
> >
> >
> 
> 
> -- 
> Best Regards
>  Guo Ren
>
diff mbox series

Patch

diff --git a/include/asm-generic/spinlock.h b/include/asm-generic/spinlock.h
index 90803a826ba0..4773334ee638 100644
--- a/include/asm-generic/spinlock.h
+++ b/include/asm-generic/spinlock.h
@@ -32,7 +32,7 @@ 
 
 static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
 {
-	u32 val = atomic_fetch_add(1<<16, lock);
+	u32 val = atomic_fetch_add(1<<16, &lock->val);
 	u16 ticket = val >> 16;
 
 	if (ticket == (u16)val)
@@ -46,31 +46,31 @@  static __always_inline void arch_spin_lock(arch_spinlock_t *lock)
 	 * have no outstanding writes due to the atomic_fetch_add() the extra
 	 * orderings are free.
 	 */
-	atomic_cond_read_acquire(lock, ticket == (u16)VAL);
+	atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
 	smp_mb();
 }
 
 static __always_inline bool arch_spin_trylock(arch_spinlock_t *lock)
 {
-	u32 old = atomic_read(lock);
+	u32 old = atomic_read(&lock->val);
 
 	if ((old >> 16) != (old & 0xffff))
 		return false;
 
-	return atomic_try_cmpxchg(lock, &old, old + (1<<16)); /* SC, for RCsc */
+	return atomic_try_cmpxchg(&lock->val, &old, old + (1<<16)); /* SC, for RCsc */
 }
 
 static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)
 {
 	u16 *ptr = (u16 *)lock + IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
-	u32 val = atomic_read(lock);
+	u32 val = atomic_read(&lock->val);
 
 	smp_store_release(ptr, (u16)val + 1);
 }
 
 static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
 {
-	u32 val = lock.counter;
+	u32 val = lock.val.counter;
 
 	return ((val >> 16) == (val & 0xffff));
 }
@@ -84,7 +84,7 @@  static __always_inline int arch_spin_is_locked(arch_spinlock_t *lock)
 
 static __always_inline int arch_spin_is_contended(arch_spinlock_t *lock)
 {
-	u32 val = atomic_read(lock);
+	u32 val = atomic_read(&lock->val);
 
 	return (s16)((val >> 16) - (val & 0xffff)) > 1;
 }
diff --git a/include/asm-generic/spinlock_types.h b/include/asm-generic/spinlock_types.h
index 8962bb730945..f534aa5de394 100644
--- a/include/asm-generic/spinlock_types.h
+++ b/include/asm-generic/spinlock_types.h
@@ -3,15 +3,7 @@ 
 #ifndef __ASM_GENERIC_SPINLOCK_TYPES_H
 #define __ASM_GENERIC_SPINLOCK_TYPES_H
 
-#include <linux/types.h>
-typedef atomic_t arch_spinlock_t;
-
-/*
- * qrwlock_types depends on arch_spinlock_t, so we must typedef that before the
- * include.
- */
-#include <asm/qrwlock_types.h>
-
-#define __ARCH_SPIN_LOCK_UNLOCKED	ATOMIC_INIT(0)
+#include <asm-generic/qspinlock_types.h>
+#include <asm-generic/qrwlock_types.h>
 
 #endif /* __ASM_GENERIC_SPINLOCK_TYPES_H */