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

[Shuai Xue <xueshuai@linux.alibaba.com>]

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@linux.alibaba.com>
>> ---
>>   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