Re: [PATCH 2/3] ACPI: APEI: GHES: Extract helper functions for error status handling

[Shuai Xue]

On 12/17/25 9:25 AM, Hanjun Guo wrote:
> On 2025/12/3 21:02, Shuai Xue wrote:
> > Refactors the GHES driver by extracting common functionality into
> > reusable helper functions:
> >
> > 1. ghes_has_active_errors() - Checks if any error sources in a given list
> >     have active errors
> > 2. ghes_map_error_status() - Maps error status address to virtual address
> > 3. ghes_unmap_error_status() - Unmaps error status virtual address
> >
> > These helpers eliminate code duplication in the NMI path and prepare for
> > similar usage in the SEA path in a subsequent patch.
> >
> > No functional change intended.
> >
> > Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/acpi/apei/ghes.c | 92 +++++++++++++++++++++++++++++++---------
> >   1 file changed, 72 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > index 62713b612865..2c7f3ca6ce50 100644
> > --- a/drivers/acpi/apei/ghes.c
> > +++ b/drivers/acpi/apei/ghes.c
> > @@ -1375,6 +1375,74 @@ static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list,
> >       return ret;
> >   }
> > +/**
> > + * ghes_has_active_errors - Check if there are active errors in error sources
> > + * @ghes_list: List of GHES entries to check for active errors
> > + *
> > + * This function iterates through all GHES entries in the given list and
> > + * checks if any of them has active error status by reading the error
> > + * status register.
> > + *
> > + * Return: true if at least one source has active error, false otherwise.
> > + */
> > +static bool __maybe_unused ghes_has_active_errors(struct list_head *ghes_list)
> > +{
> > +    bool active_error = false;
> > +    struct ghes *ghes;
> > +
> > +    rcu_read_lock();
> > +    list_for_each_entry_rcu(ghes, ghes_list, list) {
> > +        if (ghes->error_status_vaddr &&
> > +            readl(ghes->error_status_vaddr)) {
> > +            active_error = true;
> > +            break;
> > +        }
> > +    }
> > +    rcu_read_unlock();
> > +
> > +    return active_error;
> > +}
> > +
> > +/**
> > + * ghes_map_error_status - Map error status address to virtual address
> > + * @ghes: pointer to GHES structure
> > + *
> > + * Reads the error status address from ACPI HEST table and maps it to a virtual
> > + * address that can be accessed by the kernel.
> > + *
> > + * Return: 0 on success, error code on failure.
> > + */
> > +static int __maybe_unused ghes_map_error_status(struct ghes *ghes)
> > +{
> > +    struct acpi_hest_generic *g = ghes->generic;
> > +    u64 paddr;
> > +    int rc;
> > +
> > +    rc = apei_read(&paddr, &g->error_status_address);
> > +    if (rc)
> > +        return rc;
> > +    ghes->error_status_vaddr =
> > +        acpi_os_ioremap(paddr, sizeof(ghes->estatus->block_status));
> > +    if (!ghes->error_status_vaddr)
> > +        return AE_BAD_ADDRESS;
>
> Same update here.

Got it. Will fix it.

> > +
> > +    return 0;
> > +}
> > +
> > +/**
> > + * ghes_unmap_error_status - Unmap error status virtual address
> > + * @ghes: pointer to GHES structure
> > + *
> > + * Unmaps the error status address if it was previously mapped.
> > + */
> > +static void __maybe_unused ghes_unmap_error_status(struct ghes *ghes)
> > +{
> > +    if (ghes->error_status_vaddr) {
> > +        iounmap(ghes->error_status_vaddr);
> > +        ghes->error_status_vaddr = NULL;
> > +    }
> > +}
> > +
> >   #ifdef CONFIG_ACPI_APEI_SEA
> >   static LIST_HEAD(ghes_sea);
> > @@ -1425,20 +1493,9 @@ static LIST_HEAD(ghes_nmi);
> >   static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
> >   {
> >       static DEFINE_RAW_SPINLOCK(ghes_notify_lock_nmi);
> > -    bool active_error = false;
> >       int ret = NMI_DONE;
> > -    struct ghes *ghes;
> > -    rcu_read_lock();
> > -    list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
> > -        if (ghes->error_status_vaddr && readl(ghes->error_status_vaddr)) {
> > -            active_error = true;
> > -            break;
> > -        }
> > -    }
> > -    rcu_read_unlock();
> > -
> > -    if (!active_error)
> > +    if (!ghes_has_active_errors(&ghes_nmi))
> >           return ret;
> >       if (!atomic_add_unless(&ghes_in_nmi, 1, 1))
> > @@ -1455,16 +1512,11 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
> >   static int ghes_nmi_add(struct ghes *ghes)
> >   {
> > -    struct acpi_hest_generic *g = ghes->generic;
> > -    u64 paddr;
> >       int rc;
> > -    rc = apei_read(&paddr, &g->error_status_address);
> > +    rc = ghes_map_error_status(ghes);
> >       if (rc)
> >           return rc;
> > -    ghes->error_status_vaddr = acpi_os_ioremap(paddr, sizeof(ghes->estatus->block_status));
> > -    if (!ghes->error_status_vaddr)
> > -        return AE_BAD_ADDRESS;
> >       mutex_lock(&ghes_list_mutex);
> >       if (list_empty(&ghes_nmi))
> > @@ -1483,8 +1535,7 @@ static void ghes_nmi_remove(struct ghes *ghes)
> >           unregister_nmi_handler(NMI_LOCAL, "ghes");
> >       mutex_unlock(&ghes_list_mutex);
> > -    if (ghes->error_status_vaddr)
> > -        iounmap(ghes->error_status_vaddr);
> > +    ghes_unmap_error_status(ghes);
> >       /*
> >        * To synchronize with NMI handler, ghes can only be
> > @@ -1492,6 +1543,7 @@ static void ghes_nmi_remove(struct ghes *ghes)
> >        */
> >       synchronize_rcu();
> >   }
> > +
>
> I think it's not belong to this patch.

Will drop it.

> Thanks
> Hanjun
Thanks.
Shuai