Commit feb2d380 authored by Shuai Xue's avatar Shuai Xue Committed by Rafael J. Wysocki
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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: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarShuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: default avatarBreno Leitao <leitao@debian.org>
Reviewed-by: default avatarHanjun Guo <guohanjun@huawei.com>
Link: https://patch.msgid.link/20260112032239.30023-3-xueshuai@linux.alibaba.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f2edc1fb

drivers/acpi/apei/ghes.c

+68 −21
Original line number Diff line number Diff line
@@ -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