Subject: Re: [PATCH v5 06/10] ACPI: APEI: GHES: move CXL CPER helpers

From: Jonathan Cameron <[email-masked]>
Date: Fri, 29 May 2026 17:16:19 +0100

On Fri, 29 May 2026 10:50:46 +0100
Ahmed Tiba <[email-masked]> wrote:

> Move the CXL CPER handling paths out of ghes.c and into ghes_cper.c so the
> helpers can be reused. The code is moved as-is, with the public
> prototypes updated so GHES keeps calling into the new translation unit.
> 
> Signed-off-by: Ahmed Tiba <[email-masked]>
This is going to clash with the series Terry is working on for CXL error handling.
I think this patch in particular:
https://lore.kernel.org/all/[email-masked]/

That series is high priority to land from a CXL point of view. +CC Terry

Subject to that,
Reviewed-by: Jonathan Cameron <[email-masked]>

Patch left so Terry can see it. No comments.

> ---
>  drivers/acpi/apei/ghes.c      | 132 -----------------------------------------
>  drivers/acpi/apei/ghes_cper.c | 134 ++++++++++++++++++++++++++++++++++++++++++
>  include/acpi/ghes_cper.h      |  11 ++++
>  3 files changed, 145 insertions(+), 132 deletions(-)
> 
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index 81ac51632f21..85be2ebf4d3e 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -383,69 +383,6 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
>  #endif
>  }
>  
> -/* Room for 8 entries */
> -#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
> -static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
> -		    CXL_CPER_PROT_ERR_FIFO_DEPTH);
> -
> -/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
> -static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
> -struct work_struct *cxl_cper_prot_err_work;
> -
> -static void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
> -				   int severity)
> -{
> -#ifdef CONFIG_ACPI_APEI_PCIEAER
> -	struct cxl_cper_prot_err_work_data wd;
> -
> -	if (cxl_cper_sec_prot_err_valid(prot_err))
> -		return;
> -
> -	guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
> -
> -	if (!cxl_cper_prot_err_work)
> -		return;
> -
> -	if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
> -		return;
> -
> -	if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
> -		pr_err_ratelimited("CXL CPER kfifo overflow\n");
> -		return;
> -	}
> -
> -	schedule_work(cxl_cper_prot_err_work);
> -#endif
> -}
> -
> -int cxl_cper_register_prot_err_work(struct work_struct *work)
> -{
> -	if (cxl_cper_prot_err_work)
> -		return -EINVAL;
> -
> -	guard(spinlock)(&cxl_cper_prot_err_work_lock);
> -	cxl_cper_prot_err_work = work;
> -	return 0;
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
> -
> -int cxl_cper_unregister_prot_err_work(struct work_struct *work)
> -{
> -	if (cxl_cper_prot_err_work != work)
> -		return -EINVAL;
> -
> -	guard(spinlock)(&cxl_cper_prot_err_work_lock);
> -	cxl_cper_prot_err_work = NULL;
> -	return 0;
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
> -
> -int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
> -{
> -	return kfifo_get(&cxl_cper_prot_err_fifo, wd);
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
> -
>  static void ghes_vendor_record_notifier_destroy(void *nb)
>  {
>  	ghes_unregister_vendor_record_notifier(nb);
> @@ -464,75 +401,6 @@ int devm_ghes_register_vendor_record_notifier(struct device *dev,
>  }
>  EXPORT_SYMBOL_GPL(devm_ghes_register_vendor_record_notifier);
>  
> -/* Room for 8 entries for each of the 4 event log queues */
> -#define CXL_CPER_FIFO_DEPTH 32
> -DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
> -
> -/* Synchronize schedule_work() with cxl_cper_work changes */
> -static DEFINE_SPINLOCK(cxl_cper_work_lock);
> -struct work_struct *cxl_cper_work;
> -
> -static void cxl_cper_post_event(enum cxl_event_type event_type,
> -				struct cxl_cper_event_rec *rec)
> -{
> -	struct cxl_cper_work_data wd;
> -
> -	if (rec->hdr.length <= sizeof(rec->hdr) ||
> -	    rec->hdr.length > sizeof(*rec)) {
> -		pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
> -		       rec->hdr.length);
> -		return;
> -	}
> -
> -	if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
> -		pr_err(FW_WARN "CXL CPER invalid event\n");
> -		return;
> -	}
> -
> -	guard(spinlock_irqsave)(&cxl_cper_work_lock);
> -
> -	if (!cxl_cper_work)
> -		return;
> -
> -	wd.event_type = event_type;
> -	memcpy(&wd.rec, rec, sizeof(wd.rec));
> -
> -	if (!kfifo_put(&cxl_cper_fifo, wd)) {
> -		pr_err_ratelimited("CXL CPER kfifo overflow\n");
> -		return;
> -	}
> -
> -	schedule_work(cxl_cper_work);
> -}
> -
> -int cxl_cper_register_work(struct work_struct *work)
> -{
> -	if (cxl_cper_work)
> -		return -EINVAL;
> -
> -	guard(spinlock)(&cxl_cper_work_lock);
> -	cxl_cper_work = work;
> -	return 0;
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
> -
> -int cxl_cper_unregister_work(struct work_struct *work)
> -{
> -	if (cxl_cper_work != work)
> -		return -EINVAL;
> -
> -	guard(spinlock)(&cxl_cper_work_lock);
> -	cxl_cper_work = NULL;
> -	return 0;
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
> -
> -int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
> -{
> -	return kfifo_get(&cxl_cper_fifo, wd);
> -}
> -EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
> -
>  static void ghes_log_hwerr(int sev, guid_t *sec_type)
>  {
>  	if (sev != CPER_SEV_RECOVERABLE)
> diff --git a/drivers/acpi/apei/ghes_cper.c b/drivers/acpi/apei/ghes_cper.c
> index 131980d36064..d7a666a163c3 100644
> --- a/drivers/acpi/apei/ghes_cper.c
> +++ b/drivers/acpi/apei/ghes_cper.c
> @@ -12,10 +12,12 @@
>   *   Author: Huang Ying <[email-masked]>
>   */
>  
> +#include <linux/aer.h>
>  #include <linux/err.h>
>  #include <linux/genalloc.h>
>  #include <linux/irq_work.h>
>  #include <linux/io.h>
> +#include <linux/kfifo.h>
>  #include <linux/kernel.h>
>  #include <linux/list.h>
>  #include <linux/math64.h>
> @@ -321,6 +323,138 @@ void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
>  	schedule_work(&entry->work);
>  }
>  
> +/* Room for 8 entries */
> +#define CXL_CPER_PROT_ERR_FIFO_DEPTH 8
> +static DEFINE_KFIFO(cxl_cper_prot_err_fifo, struct cxl_cper_prot_err_work_data,
> +		    CXL_CPER_PROT_ERR_FIFO_DEPTH);
> +
> +/* Synchronize schedule_work() with cxl_cper_prot_err_work changes */
> +static DEFINE_SPINLOCK(cxl_cper_prot_err_work_lock);
> +struct work_struct *cxl_cper_prot_err_work;
> +
> +void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
> +			    int severity)
> +{
> +#ifdef CONFIG_ACPI_APEI_PCIEAER
> +	struct cxl_cper_prot_err_work_data wd;
> +
> +	if (cxl_cper_sec_prot_err_valid(prot_err))
> +		return;
> +
> +	guard(spinlock_irqsave)(&cxl_cper_prot_err_work_lock);
> +
> +	if (!cxl_cper_prot_err_work)
> +		return;
> +
> +	if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
> +		return;
> +
> +	if (!kfifo_put(&cxl_cper_prot_err_fifo, wd)) {
> +		pr_err_ratelimited("CXL CPER kfifo overflow\n");
> +		return;
> +	}
> +
> +	schedule_work(cxl_cper_prot_err_work);
> +#endif
> +}
> +
> +int cxl_cper_register_prot_err_work(struct work_struct *work)
> +{
> +	if (cxl_cper_prot_err_work)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&cxl_cper_prot_err_work_lock);
> +	cxl_cper_prot_err_work = work;
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_register_prot_err_work, "CXL");
> +
> +int cxl_cper_unregister_prot_err_work(struct work_struct *work)
> +{
> +	if (cxl_cper_prot_err_work != work)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&cxl_cper_prot_err_work_lock);
> +	cxl_cper_prot_err_work = NULL;
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_prot_err_work, "CXL");
> +
> +int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd)
> +{
> +	return kfifo_get(&cxl_cper_prot_err_fifo, wd);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_prot_err_kfifo_get, "CXL");
> +
> +/* Room for 8 entries for each of the 4 event log queues */
> +#define CXL_CPER_FIFO_DEPTH 32
> +static DEFINE_KFIFO(cxl_cper_fifo, struct cxl_cper_work_data, CXL_CPER_FIFO_DEPTH);
> +
> +/* Synchronize schedule_work() with cxl_cper_work changes */
> +static DEFINE_SPINLOCK(cxl_cper_work_lock);
> +struct work_struct *cxl_cper_work;
> +
> +void cxl_cper_post_event(enum cxl_event_type event_type,
> +			 struct cxl_cper_event_rec *rec)
> +{
> +	struct cxl_cper_work_data wd;
> +
> +	if (rec->hdr.length <= sizeof(rec->hdr) ||
> +	    rec->hdr.length > sizeof(*rec)) {
> +		pr_err(FW_WARN "CXL CPER Invalid section length (%u)\n",
> +		       rec->hdr.length);
> +		return;
> +	}
> +
> +	if (!(rec->hdr.validation_bits & CPER_CXL_COMP_EVENT_LOG_VALID)) {
> +		pr_err(FW_WARN "CXL CPER invalid event\n");
> +		return;
> +	}
> +
> +	guard(spinlock_irqsave)(&cxl_cper_work_lock);
> +
> +	if (!cxl_cper_work)
> +		return;
> +
> +	wd.event_type = event_type;
> +	memcpy(&wd.rec, rec, sizeof(wd.rec));
> +
> +	if (!kfifo_put(&cxl_cper_fifo, wd)) {
> +		pr_err_ratelimited("CXL CPER kfifo overflow\n");
> +		return;
> +	}
> +
> +	schedule_work(cxl_cper_work);
> +}
> +
> +int cxl_cper_register_work(struct work_struct *work)
> +{
> +	if (cxl_cper_work)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&cxl_cper_work_lock);
> +	cxl_cper_work = work;
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_register_work, "CXL");
> +
> +int cxl_cper_unregister_work(struct work_struct *work)
> +{
> +	if (cxl_cper_work != work)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&cxl_cper_work_lock);
> +	cxl_cper_work = NULL;
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_unregister_work, "CXL");
> +
> +int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd)
> +{
> +	return kfifo_get(&cxl_cper_fifo, wd);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_cper_kfifo_get, "CXL");
> +
>  /*
>   * GHES error status reporting throttle, to report more kinds of
>   * errors, instead of just most frequently occurred errors.
> diff --git a/include/acpi/ghes_cper.h b/include/acpi/ghes_cper.h
> index 51725f25c516..dd49e9179b63 100644
> --- a/include/acpi/ghes_cper.h
> +++ b/include/acpi/ghes_cper.h
> @@ -20,6 +20,7 @@
>  #include <linux/workqueue.h>
>  
>  #include <acpi/ghes.h>
> +#include <cxl/event.h>
>  
>  #define GHES_PFX	"GHES: "
>  
> @@ -106,5 +107,15 @@ void ghes_estatus_cache_add(struct acpi_hest_generic *generic,
>  			    struct acpi_hest_generic_status *estatus);
>  void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata,
>  				   int sev);
> +void cxl_cper_post_prot_err(struct cxl_cper_sec_prot_err *prot_err,
> +			    int severity);
> +int cxl_cper_register_prot_err_work(struct work_struct *work);
> +int cxl_cper_unregister_prot_err_work(struct work_struct *work);
> +int cxl_cper_prot_err_kfifo_get(struct cxl_cper_prot_err_work_data *wd);
> +void cxl_cper_post_event(enum cxl_event_type event_type,
> +			 struct cxl_cper_event_rec *rec);
> +int cxl_cper_register_work(struct work_struct *work);
> +int cxl_cper_unregister_work(struct work_struct *work);
> +int cxl_cper_kfifo_get(struct cxl_cper_work_data *wd);
>  
>  #endif /* ACPI_APEI_GHES_CPER_H */
>