Re: [PATCH v4 2/7] cxl/core: Remove CONFIG_CXL_SUSPEND and always build suspend.o

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Mon, 9 Jun 2025 16:25:49 -0700
"Koralahalli Channabasappa, Smita" <Smita.KoralahalliChannabasappa@amd.com> wrote:

> On 6/9/2025 4:02 AM, Jonathan Cameron wrote:
> > On Tue, 3 Jun 2025 22:19:44 +0000
> > Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> wrote:
> >   
> >> In preparation for soft-reserved resource handling, make the suspend
> >> infrastructure always available by removing the CONFIG_CXL_SUSPEND
> >> Kconfig option.
> >>
> >> This ensures cxl_mem_active_inc()/dec() and cxl_mem_active() are
> >> unconditionally available, enabling coordination between cxl_pci and
> >> cxl_mem drivers during region setup and hotplug operations.  
> > 
> > If these are no longer just being used for suspend, given there
> > is nothing else in the file, maybe move them to somewhere else?  
> 
> There was recommendation to move the wait queue declaration and its
> related changes to acpi.c. I was considering that. Let me know if there 
> is any other best place for this.
> 
I wasn't sure on the best location (which is why I was lazy an didn't
suggest one ;)  Dan, Dave etc anyone have strong mental model for where
this should be?

> Thanks
> Smita
> > 
> >   
> >>
> >> Co-developed-by: Nathan Fontenot <Nathan.Fontenot@amd.com>
> >> Signed-off-by: Nathan Fontenot <Nathan.Fontenot@amd.com>
> >> Co-developed-by: Terry Bowman <terry.bowman@amd.com>
> >> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> >> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
> >> ---
> >>   drivers/cxl/Kconfig        | 4 ----
> >>   drivers/cxl/core/Makefile  | 2 +-
> >>   drivers/cxl/core/suspend.c | 5 ++++-
> >>   drivers/cxl/cxlmem.h       | 9 ---------
> >>   include/linux/pm.h         | 7 -------
> >>   5 files changed, 5 insertions(+), 22 deletions(-)
> >>
> >> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
> >> index cf1ba673b8c2..d09144c2002e 100644
> >> --- a/drivers/cxl/Kconfig
> >> +++ b/drivers/cxl/Kconfig
> >> @@ -118,10 +118,6 @@ config CXL_PORT
> >>   	default CXL_BUS
> >>   	tristate
> >>   
> >> -config CXL_SUSPEND
> >> -	def_bool y
> >> -	depends on SUSPEND && CXL_MEM
> >> -
> >>   config CXL_REGION
> >>   	bool "CXL: Region Support"
> >>   	default CXL_BUS
> >> diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
> >> index 086df97a0fcf..035864db8a32 100644
> >> --- a/drivers/cxl/core/Makefile
> >> +++ b/drivers/cxl/core/Makefile
> >> @@ -1,6 +1,6 @@
> >>   # SPDX-License-Identifier: GPL-2.0
> >>   obj-$(CONFIG_CXL_BUS) += cxl_core.o
> >> -obj-$(CONFIG_CXL_SUSPEND) += suspend.o
> >> +obj-y += suspend.o
> >>   
> >>   ccflags-y += -I$(srctree)/drivers/cxl
> >>   CFLAGS_trace.o = -DTRACE_INCLUDE_PATH=. -I$(src)
> >> diff --git a/drivers/cxl/core/suspend.c b/drivers/cxl/core/suspend.c
> >> index 29aa5cc5e565..5ba4b4de0e33 100644
> >> --- a/drivers/cxl/core/suspend.c
> >> +++ b/drivers/cxl/core/suspend.c
> >> @@ -8,7 +8,10 @@ static atomic_t mem_active;
> >>   
> >>   bool cxl_mem_active(void)
> >>   {
> >> -	return atomic_read(&mem_active) != 0;
> >> +	if (IS_ENABLED(CONFIG_CXL_MEM))
> >> +		return atomic_read(&mem_active) != 0;
> >> +
> >> +	return false;
> >>   }
> >>   
> >>   void cxl_mem_active_inc(void)
> >> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> >> index 3ec6b906371b..1bd1e88c4cc0 100644
> >> --- a/drivers/cxl/cxlmem.h
> >> +++ b/drivers/cxl/cxlmem.h
> >> @@ -853,17 +853,8 @@ int cxl_trigger_poison_list(struct cxl_memdev *cxlmd);
> >>   int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa);
> >>   int cxl_clear_poison(struct cxl_memdev *cxlmd, u64 dpa);
> >>   
> >> -#ifdef CONFIG_CXL_SUSPEND
> >>   void cxl_mem_active_inc(void);
> >>   void cxl_mem_active_dec(void);
> >> -#else
> >> -static inline void cxl_mem_active_inc(void)
> >> -{
> >> -}
> >> -static inline void cxl_mem_active_dec(void)
> >> -{
> >> -}
> >> -#endif
> >>   
> >>   int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd);
> >>   
> >> diff --git a/include/linux/pm.h b/include/linux/pm.h
> >> index f0bd8fbae4f2..415928e0b6ca 100644
> >> --- a/include/linux/pm.h
> >> +++ b/include/linux/pm.h
> >> @@ -35,14 +35,7 @@ static inline void pm_vt_switch_unregister(struct device *dev)
> >>   }
> >>   #endif /* CONFIG_VT_CONSOLE_SLEEP */
> >>   
> >> -#ifdef CONFIG_CXL_SUSPEND
> >>   bool cxl_mem_active(void);
> >> -#else
> >> -static inline bool cxl_mem_active(void)
> >> -{
> >> -	return false;
> >> -}
> >> -#endif
> >>   
> >>   /*
> >>    * Device power management  
> >   
>