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ACPI: APEI: GHES: Extract helper functions for error status handling 

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
4. Use `guard(rcu)()` instead of explicit `rcu_read_lock()`/`rcu_read_unlock()`.

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.

Tested-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Link: https://patch.msgid.link/20260112032239.30023-3-xueshuai@linux.alibaba.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Shuai Xue 2026-01-12 11:22:38 +08:00 committed by Rafael J. Wysocki
parent f2edc1fb9c
commit feb2d38013
1 changed files with 68 additions and 21 deletions
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89
drivers/acpi/apei/ghes.c
View File

@ -1434,6 +1434,71 @@ 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)
{
struct ghes *ghes;
guard(rcu)();
list_for_each_entry_rcu(ghes, ghes_list, list) {
if (ghes->error_status_vaddr &&
readl(ghes->error_status_vaddr))
return true;
}
return false;
}
/**
* 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 -EINVAL;
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);
@ -1484,20 +1549,9 @@ 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))
@ -1514,18 +1568,12 @@ 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 -EINVAL;
mutex_lock(&ghes_list_mutex);
if (list_empty(&ghes_nmi))
register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes");
@ -1543,8 +1591,7 @@ 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