Re: [PATCH cmpxchg 14/14] riscv: Emulate one-byte cmpxchg

Paul E. McKenney
2024-04-09T18:08:46Z

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