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Date: Tue, 9 Apr 2024 11:08:45 -0700
From: "Paul E. McKenney" <paulmck@kernel.org>
To: Andrea Parri <parri.andrea@gmail.com>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	elver@google.com, akpm@linux-foundation.org, tglx@linutronix.de,
	peterz@infradead.org, dianders@chromium.org, pmladek@suse.com,
	torvalds@linux-foundation.org, Arnd Bergmann <arnd@arndb.de>,
	Yujie Liu <yujie.liu@intel.com>,
	Andi Shyti <andi.shyti@linux.intel.com>,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	linux-riscv@lists.infradead.org,
	Palmer Dabbelt <palmer@rivosinc.com>
Subject: Re: [PATCH cmpxchg 14/14] riscv: Emulate one-byte cmpxchg
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 <20240408174944.907695-14-paulmck@kernel.org>
 <ZhV8a+pWAnJQ3Ljp@andrea>
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In-Reply-To: <ZhV8a+pWAnJQ3Ljp@andrea>

On Tue, Apr 09, 2024 at 07:35:39PM +0200, Andrea Parri wrote:
> Hi Paul,
> 
> > @@ -170,6 +171,9 @@
> >  	__typeof__(*(ptr)) __ret;					\
> >  	register unsigned int __rc;					\
> >  	switch (size) {							\
> > +	case 1:								\
> > +		__ret = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)__ptr, (uintptr_t)__old, (uintptr_t)__new); \
> > +		break;							\
> >  	case 4:								\
> >  		__asm__ __volatile__ (					\
> >  			"0:	lr.w %0, %2\n"				\
> > @@ -214,6 +218,9 @@
> >  	__typeof__(*(ptr)) __ret;					\
> >  	register unsigned int __rc;					\
> >  	switch (size) {							\
> > +	case 1:								\
> > +		__ret = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)__ptr, __old, __new); \
> > +		break;							\
> >  	case 4:								\
> >  		__asm__ __volatile__ (					\
> >  			"0:	lr.w %0, %2\n"				\
> > @@ -260,6 +267,9 @@
> >  	__typeof__(*(ptr)) __ret;					\
> >  	register unsigned int __rc;					\
> >  	switch (size) {							\
> > +	case 1:								\
> > +		__ret = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)__ptr, __old, __new); \
> > +		break;							\
> >  	case 4:								\
> >  		__asm__ __volatile__ (					\
> >  			RISCV_RELEASE_BARRIER				\
> > @@ -306,6 +316,9 @@
> >  	__typeof__(*(ptr)) __ret;					\
> >  	register unsigned int __rc;					\
> >  	switch (size) {							\
> > +	case 1:								\
> > +		__ret = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)__ptr, __old, __new); \
> > +		break;							\
> >  	case 4:								\
> >  		__asm__ __volatile__ (					\
> >  			"0:	lr.w %0, %2\n"				\
> 
> Seems the last three are missing uintptr_t casts?

Indeed they are, and good eyes!

However, Liu, Yujie beat you to it, and this commit contains the fix:

4d5c72a34948 ("riscv: Emulate one-byte cmpxchg")

							Thanx, Paul