linux-kernel - Re: [PATCH v4 3/7] cxl/pci: Add pci_loaded tracking to mark PCI driver readiness

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2b5c1df3-a279-4208-ab21-7ae033403939@fujitsu.com>
Date: Wed, 4 Jun 2025 09:29:35 +0000
From: "Zhijian Li (Fujitsu)" <lizhijian@...itsu.com>
To: Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>,
	"linux-cxl@...r.kernel.org" <linux-cxl@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"nvdimm@...ts.linux.dev" <nvdimm@...ts.linux.dev>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>
CC: Davidlohr Bueso <dave@...olabs.net>, Jonathan Cameron
	<jonathan.cameron@...wei.com>, Dave Jiang <dave.jiang@...el.com>, Alison
 Schofield <alison.schofield@...el.com>, Vishal Verma
	<vishal.l.verma@...el.com>, Ira Weiny <ira.weiny@...el.com>, Dan Williams
	<dan.j.williams@...el.com>, Matthew Wilcox <willy@...radead.org>, Jan Kara
	<jack@...e.cz>, "Rafael J . Wysocki" <rafael@...nel.org>, Len Brown
	<len.brown@...el.com>, Pavel Machek <pavel@...nel.org>, Li Ming
	<ming.li@...omail.com>, Jeff Johnson <jeff.johnson@....qualcomm.com>, Ying
 Huang <huang.ying.caritas@...il.com>, "Xingtao Yao (Fujitsu)"
	<yaoxt.fnst@...itsu.com>, Peter Zijlstra <peterz@...radead.org>, Greg KH
	<gregkh@...uxfoundation.org>, Nathan Fontenot <nathan.fontenot@....com>,
	Terry Bowman <terry.bowman@....com>, Robert Richter <rrichter@....com>,
	Benjamin Cheatham <benjamin.cheatham@....com>, PradeepVineshReddy Kodamati
	<PradeepVineshReddy.Kodamati@....com>
Subject: Re: [PATCH v4 3/7] cxl/pci: Add pci_loaded tracking to mark PCI
 driver readiness



On 04/06/2025 06:19, Smita Koralahalli wrote:
> Introduce a pci_loaded flag similar to mem_active, and define
> mark_cxl_pci_loaded() to indicate when the PCI driver has initialized.
> 
> This will be used by other CXL components, such as cxl_acpi and the soft
> reserved resource handling logic, to coordinate initialization and ensure
> that dependent operations proceed only after both cxl_pci and cxl_mem
> drivers are ready.
> 
> Co-developed-by: Nathan Fontenot <Nathan.Fontenot@....com>
> Signed-off-by: Nathan Fontenot <Nathan.Fontenot@....com>
> Co-developed-by: Terry Bowman <terry.bowman@....com>
> Signed-off-by: Terry Bowman <terry.bowman@....com>
> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>
> ---
>   drivers/cxl/core/suspend.c | 8 ++++++++
>   drivers/cxl/cxlpci.h       | 1 +
>   drivers/cxl/pci.c          | 2 ++
>   3 files changed, 11 insertions(+)
> 
> diff --git a/drivers/cxl/core/suspend.c b/drivers/cxl/core/suspend.c
> index 5ba4b4de0e33..72818a2c8ec8 100644
> --- a/drivers/cxl/core/suspend.c
> +++ b/drivers/cxl/core/suspend.c
> @@ -3,8 +3,10 @@
>   #include <linux/atomic.h>
>   #include <linux/export.h>
>   #include "cxlmem.h"
> +#include "cxlpci.h"
>   
>   static atomic_t mem_active;
> +static atomic_t pci_loaded;


I find it odd to place these changes in suspend.c. Also, I noticed that in a
subsequent patch, DJ has mentioned (and I agree) that this patch is unnecessary.


Thanks
Zhijian


>   
>   bool cxl_mem_active(void)
>   {
> @@ -25,3 +27,9 @@ void cxl_mem_active_dec(void)
>   	atomic_dec(&mem_active);
>   }
>   EXPORT_SYMBOL_NS_GPL(cxl_mem_active_dec, "CXL");
> +
> +void mark_cxl_pci_loaded(void)
> +{
> +	atomic_inc(&pci_loaded);
> +}
> +EXPORT_SYMBOL_NS_GPL(mark_cxl_pci_loaded, "CXL");
> diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
> index 54e219b0049e..5a811ac63fcf 100644
> --- a/drivers/cxl/cxlpci.h
> +++ b/drivers/cxl/cxlpci.h
> @@ -135,4 +135,5 @@ void read_cdat_data(struct cxl_port *port);
>   void cxl_cor_error_detected(struct pci_dev *pdev);
>   pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
>   				    pci_channel_state_t state);
> +void mark_cxl_pci_loaded(void);
>   #endif /* __CXL_PCI_H__ */
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 785aa2af5eaa..b019bd324dba 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -1189,6 +1189,8 @@ static int __init cxl_pci_driver_init(void)
>   	if (rc)
>   		pci_unregister_driver(&cxl_pci_driver);
>   
> +	mark_cxl_pci_loaded();
> +
>   	return rc;
>   }
>